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linux/drivers/net/ns83820.c

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#define VERSION "0.23"
/* ns83820.c by Benjamin LaHaise with contributions.
*
* Questions/comments/discussion to linux-ns83820@kvack.org.
*
* $Revision: 1.34.2.23 $
*
* Copyright 2001 Benjamin LaHaise.
* Copyright 2001, 2002 Red Hat.
*
* Mmmm, chocolate vanilla mocha...
*
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
*
* ChangeLog
* =========
* 20010414 0.1 - created
* 20010622 0.2 - basic rx and tx.
* 20010711 0.3 - added duplex and link state detection support.
* 20010713 0.4 - zero copy, no hangs.
* 0.5 - 64 bit dma support (davem will hate me for this)
* - disable jumbo frames to avoid tx hangs
* - work around tx deadlocks on my 1.02 card via
* fiddling with TXCFG
* 20010810 0.6 - use pci dma api for ringbuffers, work on ia64
* 20010816 0.7 - misc cleanups
* 20010826 0.8 - fix critical zero copy bugs
* 0.9 - internal experiment
* 20010827 0.10 - fix ia64 unaligned access.
* 20010906 0.11 - accept all packets with checksum errors as
* otherwise fragments get lost
* - fix >> 32 bugs
* 0.12 - add statistics counters
* - add allmulti/promisc support
* 20011009 0.13 - hotplug support, other smaller pci api cleanups
* 20011204 0.13a - optical transceiver support added
* by Michael Clark <michael@metaparadigm.com>
* 20011205 0.13b - call register_netdev earlier in initialization
* suppress duplicate link status messages
* 20011117 0.14 - ethtool GDRVINFO, GLINK support from jgarzik
* 20011204 0.15 get ppc (big endian) working
* 20011218 0.16 various cleanups
* 20020310 0.17 speedups
* 20020610 0.18 - actually use the pci dma api for highmem
* - remove pci latency register fiddling
* 0.19 - better bist support
* - add ihr and reset_phy parameters
* - gmii bus probing
* - fix missed txok introduced during performance
* tuning
* 0.20 - fix stupid RFEN thinko. i am such a smurf.
* 20040828 0.21 - add hardware vlan accleration
* by Neil Horman <nhorman@redhat.com>
* 20050406 0.22 - improved DAC ifdefs from Andi Kleen
* - removal of dead code from Adrian Bunk
* - fix half duplex collision behaviour
* Driver Overview
* ===============
*
* This driver was originally written for the National Semiconductor
* 83820 chip, a 10/100/1000 Mbps 64 bit PCI ethernet NIC. Hopefully
* this code will turn out to be a) clean, b) correct, and c) fast.
* With that in mind, I'm aiming to split the code up as much as
* reasonably possible. At present there are X major sections that
* break down into a) packet receive, b) packet transmit, c) link
* management, d) initialization and configuration. Where possible,
* these code paths are designed to run in parallel.
*
* This driver has been tested and found to work with the following
* cards (in no particular order):
*
* Cameo SOHO-GA2000T SOHO-GA2500T
* D-Link DGE-500T
* PureData PDP8023Z-TG
* SMC SMC9452TX SMC9462TX
* Netgear GA621
*
* Special thanks to SMC for providing hardware to test this driver on.
*
* Reports of success or failure would be greatly appreciated.
*/
//#define dprintk printk
#define dprintk(x...) do { } while (0)
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/types.h>
#include <linux/pci.h>
#include <linux/dma-mapping.h>
#include <linux/netdevice.h>
#include <linux/etherdevice.h>
#include <linux/delay.h>
#include <linux/workqueue.h>
#include <linux/init.h>
#include <linux/ip.h> /* for iph */
#include <linux/in.h> /* for IPPROTO_... */
#include <linux/compiler.h>
#include <linux/prefetch.h>
#include <linux/ethtool.h>
#include <linux/timer.h>
#include <linux/if_vlan.h>
#include <linux/rtnetlink.h>
#include <linux/jiffies.h>
#include <asm/io.h>
#include <asm/uaccess.h>
#include <asm/system.h>
#define DRV_NAME "ns83820"
/* Global parameters. See module_param near the bottom. */
static int ihr = 2;
static int reset_phy = 0;
static int lnksts = 0; /* CFG_LNKSTS bit polarity */
/* Dprintk is used for more interesting debug events */
#undef Dprintk
#define Dprintk dprintk
/* tunables */
#define RX_BUF_SIZE 1500 /* 8192 */
#if defined(CONFIG_VLAN_8021Q) || defined(CONFIG_VLAN_8021Q_MODULE)
#define NS83820_VLAN_ACCEL_SUPPORT
#endif
/* Must not exceed ~65000. */
#define NR_RX_DESC 64
#define NR_TX_DESC 128
/* not tunable */
#define REAL_RX_BUF_SIZE (RX_BUF_SIZE + 14) /* rx/tx mac addr + type */
#define MIN_TX_DESC_FREE 8
/* register defines */
#define CFGCS 0x04
#define CR_TXE 0x00000001
#define CR_TXD 0x00000002
/* Ramit : Here's a tip, don't do a RXD immediately followed by an RXE
* The Receive engine skips one descriptor and moves
* onto the next one!! */
#define CR_RXE 0x00000004
#define CR_RXD 0x00000008
#define CR_TXR 0x00000010
#define CR_RXR 0x00000020
#define CR_SWI 0x00000080
#define CR_RST 0x00000100
#define PTSCR_EEBIST_FAIL 0x00000001
#define PTSCR_EEBIST_EN 0x00000002
#define PTSCR_EELOAD_EN 0x00000004
#define PTSCR_RBIST_FAIL 0x000001b8
#define PTSCR_RBIST_DONE 0x00000200
#define PTSCR_RBIST_EN 0x00000400
#define PTSCR_RBIST_RST 0x00002000
#define MEAR_EEDI 0x00000001
#define MEAR_EEDO 0x00000002
#define MEAR_EECLK 0x00000004
#define MEAR_EESEL 0x00000008
#define MEAR_MDIO 0x00000010
#define MEAR_MDDIR 0x00000020
#define MEAR_MDC 0x00000040
#define ISR_TXDESC3 0x40000000
#define ISR_TXDESC2 0x20000000
#define ISR_TXDESC1 0x10000000
#define ISR_TXDESC0 0x08000000
#define ISR_RXDESC3 0x04000000
#define ISR_RXDESC2 0x02000000
#define ISR_RXDESC1 0x01000000
#define ISR_RXDESC0 0x00800000
#define ISR_TXRCMP 0x00400000
#define ISR_RXRCMP 0x00200000
#define ISR_DPERR 0x00100000
#define ISR_SSERR 0x00080000
#define ISR_RMABT 0x00040000
#define ISR_RTABT 0x00020000
#define ISR_RXSOVR 0x00010000
#define ISR_HIBINT 0x00008000
#define ISR_PHY 0x00004000
#define ISR_PME 0x00002000
#define ISR_SWI 0x00001000
#define ISR_MIB 0x00000800
#define ISR_TXURN 0x00000400
#define ISR_TXIDLE 0x00000200
#define ISR_TXERR 0x00000100
#define ISR_TXDESC 0x00000080
#define ISR_TXOK 0x00000040
#define ISR_RXORN 0x00000020
#define ISR_RXIDLE 0x00000010
#define ISR_RXEARLY 0x00000008
#define ISR_RXERR 0x00000004
#define ISR_RXDESC 0x00000002
#define ISR_RXOK 0x00000001
#define TXCFG_CSI 0x80000000
#define TXCFG_HBI 0x40000000
#define TXCFG_MLB 0x20000000
#define TXCFG_ATP 0x10000000
#define TXCFG_ECRETRY 0x00800000
#define TXCFG_BRST_DIS 0x00080000
#define TXCFG_MXDMA1024 0x00000000
#define TXCFG_MXDMA512 0x00700000
#define TXCFG_MXDMA256 0x00600000
#define TXCFG_MXDMA128 0x00500000
#define TXCFG_MXDMA64 0x00400000
#define TXCFG_MXDMA32 0x00300000
#define TXCFG_MXDMA16 0x00200000
#define TXCFG_MXDMA8 0x00100000
#define CFG_LNKSTS 0x80000000
#define CFG_SPDSTS 0x60000000
#define CFG_SPDSTS1 0x40000000
#define CFG_SPDSTS0 0x20000000
#define CFG_DUPSTS 0x10000000
#define CFG_TBI_EN 0x01000000
#define CFG_MODE_1000 0x00400000
/* Ramit : Dont' ever use AUTO_1000, it never works and is buggy.
* Read the Phy response and then configure the MAC accordingly */
#define CFG_AUTO_1000 0x00200000
#define CFG_PINT_CTL 0x001c0000
#define CFG_PINT_DUPSTS 0x00100000
#define CFG_PINT_LNKSTS 0x00080000
#define CFG_PINT_SPDSTS 0x00040000
#define CFG_TMRTEST 0x00020000
#define CFG_MRM_DIS 0x00010000
#define CFG_MWI_DIS 0x00008000
#define CFG_T64ADDR 0x00004000
#define CFG_PCI64_DET 0x00002000
#define CFG_DATA64_EN 0x00001000
#define CFG_M64ADDR 0x00000800
#define CFG_PHY_RST 0x00000400
#define CFG_PHY_DIS 0x00000200
#define CFG_EXTSTS_EN 0x00000100
#define CFG_REQALG 0x00000080
#define CFG_SB 0x00000040
#define CFG_POW 0x00000020
#define CFG_EXD 0x00000010
#define CFG_PESEL 0x00000008
#define CFG_BROM_DIS 0x00000004
#define CFG_EXT_125 0x00000002
#define CFG_BEM 0x00000001
#define EXTSTS_UDPPKT 0x00200000
#define EXTSTS_TCPPKT 0x00080000
#define EXTSTS_IPPKT 0x00020000
#define EXTSTS_VPKT 0x00010000
#define EXTSTS_VTG_MASK 0x0000ffff
#define SPDSTS_POLARITY (CFG_SPDSTS1 | CFG_SPDSTS0 | CFG_DUPSTS | (lnksts ? CFG_LNKSTS : 0))
#define MIBC_MIBS 0x00000008
#define MIBC_ACLR 0x00000004
#define MIBC_FRZ 0x00000002
#define MIBC_WRN 0x00000001
#define PCR_PSEN (1 << 31)
#define PCR_PS_MCAST (1 << 30)
#define PCR_PS_DA (1 << 29)
#define PCR_STHI_8 (3 << 23)
#define PCR_STLO_4 (1 << 23)
#define PCR_FFHI_8K (3 << 21)
#define PCR_FFLO_4K (1 << 21)
#define PCR_PAUSE_CNT 0xFFFE
#define RXCFG_AEP 0x80000000
#define RXCFG_ARP 0x40000000
#define RXCFG_STRIPCRC 0x20000000
#define RXCFG_RX_FD 0x10000000
#define RXCFG_ALP 0x08000000
#define RXCFG_AIRL 0x04000000
#define RXCFG_MXDMA512 0x00700000
#define RXCFG_DRTH 0x0000003e
#define RXCFG_DRTH0 0x00000002
#define RFCR_RFEN 0x80000000
#define RFCR_AAB 0x40000000
#define RFCR_AAM 0x20000000
#define RFCR_AAU 0x10000000
#define RFCR_APM 0x08000000
#define RFCR_APAT 0x07800000
#define RFCR_APAT3 0x04000000
#define RFCR_APAT2 0x02000000
#define RFCR_APAT1 0x01000000
#define RFCR_APAT0 0x00800000
#define RFCR_AARP 0x00400000
#define RFCR_MHEN 0x00200000
#define RFCR_UHEN 0x00100000
#define RFCR_ULM 0x00080000
#define VRCR_RUDPE 0x00000080
#define VRCR_RTCPE 0x00000040
#define VRCR_RIPE 0x00000020
#define VRCR_IPEN 0x00000010
#define VRCR_DUTF 0x00000008
#define VRCR_DVTF 0x00000004
#define VRCR_VTREN 0x00000002
#define VRCR_VTDEN 0x00000001
#define VTCR_PPCHK 0x00000008
#define VTCR_GCHK 0x00000004
#define VTCR_VPPTI 0x00000002
#define VTCR_VGTI 0x00000001
#define CR 0x00
#define CFG 0x04
#define MEAR 0x08
#define PTSCR 0x0c
#define ISR 0x10
#define IMR 0x14
#define IER 0x18
#define IHR 0x1c
#define TXDP 0x20
#define TXDP_HI 0x24
#define TXCFG 0x28
#define GPIOR 0x2c
#define RXDP 0x30
#define RXDP_HI 0x34
#define RXCFG 0x38
#define PQCR 0x3c
#define WCSR 0x40
#define PCR 0x44
#define RFCR 0x48
#define RFDR 0x4c
#define SRR 0x58
#define VRCR 0xbc
#define VTCR 0xc0
#define VDR 0xc4
#define CCSR 0xcc
#define TBICR 0xe0
#define TBISR 0xe4
#define TANAR 0xe8
#define TANLPAR 0xec
#define TANER 0xf0
#define TESR 0xf4
#define TBICR_MR_AN_ENABLE 0x00001000
#define TBICR_MR_RESTART_AN 0x00000200
#define TBISR_MR_LINK_STATUS 0x00000020
#define TBISR_MR_AN_COMPLETE 0x00000004
#define TANAR_PS2 0x00000100
#define TANAR_PS1 0x00000080
#define TANAR_HALF_DUP 0x00000040
#define TANAR_FULL_DUP 0x00000020
#define GPIOR_GP5_OE 0x00000200
#define GPIOR_GP4_OE 0x00000100
#define GPIOR_GP3_OE 0x00000080
#define GPIOR_GP2_OE 0x00000040
#define GPIOR_GP1_OE 0x00000020
#define GPIOR_GP3_OUT 0x00000004
#define GPIOR_GP1_OUT 0x00000001
#define LINK_AUTONEGOTIATE 0x01
#define LINK_DOWN 0x02
#define LINK_UP 0x04
#define HW_ADDR_LEN sizeof(dma_addr_t)
#define desc_addr_set(desc, addr) \
do { \
((desc)[0] = cpu_to_le32(addr)); \
if (HW_ADDR_LEN == 8) \
(desc)[1] = cpu_to_le32(((u64)addr) >> 32); \
} while(0)
#define desc_addr_get(desc) \
(le32_to_cpu((desc)[0]) | \
(HW_ADDR_LEN == 8 ? ((dma_addr_t)le32_to_cpu((desc)[1]))<<32 : 0))
#define DESC_LINK 0
#define DESC_BUFPTR (DESC_LINK + HW_ADDR_LEN/4)
#define DESC_CMDSTS (DESC_BUFPTR + HW_ADDR_LEN/4)
#define DESC_EXTSTS (DESC_CMDSTS + 4/4)
#define CMDSTS_OWN 0x80000000
#define CMDSTS_MORE 0x40000000
#define CMDSTS_INTR 0x20000000
#define CMDSTS_ERR 0x10000000
#define CMDSTS_OK 0x08000000
#define CMDSTS_RUNT 0x00200000
#define CMDSTS_LEN_MASK 0x0000ffff
#define CMDSTS_DEST_MASK 0x01800000
#define CMDSTS_DEST_SELF 0x00800000
#define CMDSTS_DEST_MULTI 0x01000000
#define DESC_SIZE 8 /* Should be cache line sized */
struct rx_info {
spinlock_t lock;
int up;
long idle;
struct sk_buff *skbs[NR_RX_DESC];
__le32 *next_rx_desc;
u16 next_rx, next_empty;
__le32 *descs;
dma_addr_t phy_descs;
};
struct ns83820 {
struct net_device_stats stats;
u8 __iomem *base;
struct pci_dev *pci_dev;
struct net_device *ndev;
#ifdef NS83820_VLAN_ACCEL_SUPPORT
struct vlan_group *vlgrp;
#endif
struct rx_info rx_info;
struct tasklet_struct rx_tasklet;
unsigned ihr;
struct work_struct tq_refill;
/* protects everything below. irqsave when using. */
spinlock_t misc_lock;
u32 CFG_cache;
u32 MEAR_cache;
u32 IMR_cache;
unsigned linkstate;
spinlock_t tx_lock;
u16 tx_done_idx;
u16 tx_idx;
volatile u16 tx_free_idx; /* idx of free desc chain */
u16 tx_intr_idx;
atomic_t nr_tx_skbs;
struct sk_buff *tx_skbs[NR_TX_DESC];
char pad[16] __attribute__((aligned(16)));
__le32 *tx_descs;
dma_addr_t tx_phy_descs;
struct timer_list tx_watchdog;
};
static inline struct ns83820 *PRIV(struct net_device *dev)
{
return netdev_priv(dev);
}
#define __kick_rx(dev) writel(CR_RXE, dev->base + CR)
static inline void kick_rx(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
dprintk("kick_rx: maybe kicking\n");
if (test_and_clear_bit(0, &dev->rx_info.idle)) {
dprintk("actually kicking\n");
writel(dev->rx_info.phy_descs +
(4 * DESC_SIZE * dev->rx_info.next_rx),
dev->base + RXDP);
if (dev->rx_info.next_rx == dev->rx_info.next_empty)
printk(KERN_DEBUG "%s: uh-oh: next_rx == next_empty???\n",
ndev->name);
__kick_rx(dev);
}
}
//free = (tx_done_idx + NR_TX_DESC-2 - free_idx) % NR_TX_DESC
#define start_tx_okay(dev) \
(((NR_TX_DESC-2 + dev->tx_done_idx - dev->tx_free_idx) % NR_TX_DESC) > MIN_TX_DESC_FREE)
#ifdef NS83820_VLAN_ACCEL_SUPPORT
static void ns83820_vlan_rx_register(struct net_device *ndev, struct vlan_group *grp)
{
struct ns83820 *dev = PRIV(ndev);
spin_lock_irq(&dev->misc_lock);
spin_lock(&dev->tx_lock);
dev->vlgrp = grp;
spin_unlock(&dev->tx_lock);
spin_unlock_irq(&dev->misc_lock);
}
#endif
/* Packet Receiver
*
* The hardware supports linked lists of receive descriptors for
* which ownership is transfered back and forth by means of an
* ownership bit. While the hardware does support the use of a
* ring for receive descriptors, we only make use of a chain in
* an attempt to reduce bus traffic under heavy load scenarios.
* This will also make bugs a bit more obvious. The current code
* only makes use of a single rx chain; I hope to implement
* priority based rx for version 1.0. Goal: even under overload
* conditions, still route realtime traffic with as low jitter as
* possible.
*/
static inline void build_rx_desc(struct ns83820 *dev, __le32 *desc, dma_addr_t link, dma_addr_t buf, u32 cmdsts, u32 extsts)
{
desc_addr_set(desc + DESC_LINK, link);
desc_addr_set(desc + DESC_BUFPTR, buf);
desc[DESC_EXTSTS] = cpu_to_le32(extsts);
mb();
desc[DESC_CMDSTS] = cpu_to_le32(cmdsts);
}
#define nr_rx_empty(dev) ((NR_RX_DESC-2 + dev->rx_info.next_rx - dev->rx_info.next_empty) % NR_RX_DESC)
static inline int ns83820_add_rx_skb(struct ns83820 *dev, struct sk_buff *skb)
{
unsigned next_empty;
u32 cmdsts;
__le32 *sg;
dma_addr_t buf;
next_empty = dev->rx_info.next_empty;
/* don't overrun last rx marker */
if (unlikely(nr_rx_empty(dev) <= 2)) {
kfree_skb(skb);
return 1;
}
#if 0
dprintk("next_empty[%d] nr_used[%d] next_rx[%d]\n",
dev->rx_info.next_empty,
dev->rx_info.nr_used,
dev->rx_info.next_rx
);
#endif
sg = dev->rx_info.descs + (next_empty * DESC_SIZE);
BUG_ON(NULL != dev->rx_info.skbs[next_empty]);
dev->rx_info.skbs[next_empty] = skb;
dev->rx_info.next_empty = (next_empty + 1) % NR_RX_DESC;
cmdsts = REAL_RX_BUF_SIZE | CMDSTS_INTR;
buf = pci_map_single(dev->pci_dev, skb->data,
REAL_RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
build_rx_desc(dev, sg, 0, buf, cmdsts, 0);
/* update link of previous rx */
if (likely(next_empty != dev->rx_info.next_rx))
dev->rx_info.descs[((NR_RX_DESC + next_empty - 1) % NR_RX_DESC) * DESC_SIZE] = cpu_to_le32(dev->rx_info.phy_descs + (next_empty * DESC_SIZE * 4));
return 0;
}
static inline int rx_refill(struct net_device *ndev, gfp_t gfp)
{
struct ns83820 *dev = PRIV(ndev);
unsigned i;
unsigned long flags = 0;
if (unlikely(nr_rx_empty(dev) <= 2))
return 0;
dprintk("rx_refill(%p)\n", ndev);
if (gfp == GFP_ATOMIC)
spin_lock_irqsave(&dev->rx_info.lock, flags);
for (i=0; i<NR_RX_DESC; i++) {
struct sk_buff *skb;
long res;
/* extra 16 bytes for alignment */
skb = __netdev_alloc_skb(ndev, REAL_RX_BUF_SIZE+16, gfp);
if (unlikely(!skb))
break;
skb_reserve(skb, skb->data - PTR_ALIGN(skb->data, 16));
if (gfp != GFP_ATOMIC)
spin_lock_irqsave(&dev->rx_info.lock, flags);
res = ns83820_add_rx_skb(dev, skb);
if (gfp != GFP_ATOMIC)
spin_unlock_irqrestore(&dev->rx_info.lock, flags);
if (res) {
i = 1;
break;
}
}
if (gfp == GFP_ATOMIC)
spin_unlock_irqrestore(&dev->rx_info.lock, flags);
return i ? 0 : -ENOMEM;
}
static void rx_refill_atomic(struct net_device *ndev)
{
rx_refill(ndev, GFP_ATOMIC);
}
/* REFILL */
static inline void queue_refill(struct work_struct *work)
{
struct ns83820 *dev = container_of(work, struct ns83820, tq_refill);
struct net_device *ndev = dev->ndev;
rx_refill(ndev, GFP_KERNEL);
if (dev->rx_info.up)
kick_rx(ndev);
}
static inline void clear_rx_desc(struct ns83820 *dev, unsigned i)
{
build_rx_desc(dev, dev->rx_info.descs + (DESC_SIZE * i), 0, 0, CMDSTS_OWN, 0);
}
static void phy_intr(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
2006-03-03 19:33:57 -07:00
static const char *speeds[] = { "10", "100", "1000", "1000(?)", "1000F" };
u32 cfg, new_cfg;
u32 tbisr, tanar, tanlpar;
int speed, fullduplex, newlinkstate;
cfg = readl(dev->base + CFG) ^ SPDSTS_POLARITY;
if (dev->CFG_cache & CFG_TBI_EN) {
/* we have an optical transceiver */
tbisr = readl(dev->base + TBISR);
tanar = readl(dev->base + TANAR);
tanlpar = readl(dev->base + TANLPAR);
dprintk("phy_intr: tbisr=%08x, tanar=%08x, tanlpar=%08x\n",
tbisr, tanar, tanlpar);
if ( (fullduplex = (tanlpar & TANAR_FULL_DUP)
&& (tanar & TANAR_FULL_DUP)) ) {
/* both of us are full duplex */
writel(readl(dev->base + TXCFG)
| TXCFG_CSI | TXCFG_HBI | TXCFG_ATP,
dev->base + TXCFG);
writel(readl(dev->base + RXCFG) | RXCFG_RX_FD,
dev->base + RXCFG);
/* Light up full duplex LED */
writel(readl(dev->base + GPIOR) | GPIOR_GP1_OUT,
dev->base + GPIOR);
} else if(((tanlpar & TANAR_HALF_DUP)
&& (tanar & TANAR_HALF_DUP))
|| ((tanlpar & TANAR_FULL_DUP)
&& (tanar & TANAR_HALF_DUP))
|| ((tanlpar & TANAR_HALF_DUP)
&& (tanar & TANAR_FULL_DUP))) {
/* one or both of us are half duplex */
writel((readl(dev->base + TXCFG)
& ~(TXCFG_CSI | TXCFG_HBI)) | TXCFG_ATP,
dev->base + TXCFG);
writel(readl(dev->base + RXCFG) & ~RXCFG_RX_FD,
dev->base + RXCFG);
/* Turn off full duplex LED */
writel(readl(dev->base + GPIOR) & ~GPIOR_GP1_OUT,
dev->base + GPIOR);
}
speed = 4; /* 1000F */
} else {
/* we have a copper transceiver */
new_cfg = dev->CFG_cache & ~(CFG_SB | CFG_MODE_1000 | CFG_SPDSTS);
if (cfg & CFG_SPDSTS1)
new_cfg |= CFG_MODE_1000;
else
new_cfg &= ~CFG_MODE_1000;
speed = ((cfg / CFG_SPDSTS0) & 3);
fullduplex = (cfg & CFG_DUPSTS);
if (fullduplex) {
new_cfg |= CFG_SB;
writel(readl(dev->base + TXCFG)
| TXCFG_CSI | TXCFG_HBI,
dev->base + TXCFG);
writel(readl(dev->base + RXCFG) | RXCFG_RX_FD,
dev->base + RXCFG);
} else {
writel(readl(dev->base + TXCFG)
& ~(TXCFG_CSI | TXCFG_HBI),
dev->base + TXCFG);
writel(readl(dev->base + RXCFG) & ~(RXCFG_RX_FD),
dev->base + RXCFG);
}
if ((cfg & CFG_LNKSTS) &&
((new_cfg ^ dev->CFG_cache) != 0)) {
writel(new_cfg, dev->base + CFG);
dev->CFG_cache = new_cfg;
}
dev->CFG_cache &= ~CFG_SPDSTS;
dev->CFG_cache |= cfg & CFG_SPDSTS;
}
newlinkstate = (cfg & CFG_LNKSTS) ? LINK_UP : LINK_DOWN;
if (newlinkstate & LINK_UP
&& dev->linkstate != newlinkstate) {
netif_start_queue(ndev);
netif_wake_queue(ndev);
printk(KERN_INFO "%s: link now %s mbps, %s duplex and up.\n",
ndev->name,
speeds[speed],
fullduplex ? "full" : "half");
} else if (newlinkstate & LINK_DOWN
&& dev->linkstate != newlinkstate) {
netif_stop_queue(ndev);
printk(KERN_INFO "%s: link now down.\n", ndev->name);
}
dev->linkstate = newlinkstate;
}
static int ns83820_setup_rx(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
unsigned i;
int ret;
dprintk("ns83820_setup_rx(%p)\n", ndev);
dev->rx_info.idle = 1;
dev->rx_info.next_rx = 0;
dev->rx_info.next_rx_desc = dev->rx_info.descs;
dev->rx_info.next_empty = 0;
for (i=0; i<NR_RX_DESC; i++)
clear_rx_desc(dev, i);
writel(0, dev->base + RXDP_HI);
writel(dev->rx_info.phy_descs, dev->base + RXDP);
ret = rx_refill(ndev, GFP_KERNEL);
if (!ret) {
dprintk("starting receiver\n");
/* prevent the interrupt handler from stomping on us */
spin_lock_irq(&dev->rx_info.lock);
writel(0x0001, dev->base + CCSR);
writel(0, dev->base + RFCR);
writel(0x7fc00000, dev->base + RFCR);
writel(0xffc00000, dev->base + RFCR);
dev->rx_info.up = 1;
phy_intr(ndev);
/* Okay, let it rip */
spin_lock_irq(&dev->misc_lock);
dev->IMR_cache |= ISR_PHY;
dev->IMR_cache |= ISR_RXRCMP;
//dev->IMR_cache |= ISR_RXERR;
//dev->IMR_cache |= ISR_RXOK;
dev->IMR_cache |= ISR_RXORN;
dev->IMR_cache |= ISR_RXSOVR;
dev->IMR_cache |= ISR_RXDESC;
dev->IMR_cache |= ISR_RXIDLE;
dev->IMR_cache |= ISR_TXDESC;
dev->IMR_cache |= ISR_TXIDLE;
writel(dev->IMR_cache, dev->base + IMR);
writel(1, dev->base + IER);
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
spin_unlock(&dev->misc_lock);
kick_rx(ndev);
spin_unlock_irq(&dev->rx_info.lock);
}
return ret;
}
static void ns83820_cleanup_rx(struct ns83820 *dev)
{
unsigned i;
unsigned long flags;
dprintk("ns83820_cleanup_rx(%p)\n", dev);
/* disable receive interrupts */
spin_lock_irqsave(&dev->misc_lock, flags);
dev->IMR_cache &= ~(ISR_RXOK | ISR_RXDESC | ISR_RXERR | ISR_RXEARLY | ISR_RXIDLE);
writel(dev->IMR_cache, dev->base + IMR);
spin_unlock_irqrestore(&dev->misc_lock, flags);
/* synchronize with the interrupt handler and kill it */
dev->rx_info.up = 0;
synchronize_irq(dev->pci_dev->irq);
/* touch the pci bus... */
readl(dev->base + IMR);
/* assumes the transmitter is already disabled and reset */
writel(0, dev->base + RXDP_HI);
writel(0, dev->base + RXDP);
for (i=0; i<NR_RX_DESC; i++) {
struct sk_buff *skb = dev->rx_info.skbs[i];
dev->rx_info.skbs[i] = NULL;
clear_rx_desc(dev, i);
if (skb)
kfree_skb(skb);
}
}
static void ns83820_rx_kick(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
/*if (nr_rx_empty(dev) >= NR_RX_DESC/4)*/ {
if (dev->rx_info.up) {
rx_refill_atomic(ndev);
kick_rx(ndev);
}
}
if (dev->rx_info.up && nr_rx_empty(dev) > NR_RX_DESC*3/4)
schedule_work(&dev->tq_refill);
else
kick_rx(ndev);
if (dev->rx_info.idle)
printk(KERN_DEBUG "%s: BAD\n", ndev->name);
}
/* rx_irq
*
*/
static void rx_irq(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
struct rx_info *info = &dev->rx_info;
unsigned next_rx;
int rx_rc, len;
u32 cmdsts;
__le32 *desc;
unsigned long flags;
int nr = 0;
dprintk("rx_irq(%p)\n", ndev);
dprintk("rxdp: %08x, descs: %08lx next_rx[%d]: %p next_empty[%d]: %p\n",
readl(dev->base + RXDP),
(long)(dev->rx_info.phy_descs),
(int)dev->rx_info.next_rx,
(dev->rx_info.descs + (DESC_SIZE * dev->rx_info.next_rx)),
(int)dev->rx_info.next_empty,
(dev->rx_info.descs + (DESC_SIZE * dev->rx_info.next_empty))
);
spin_lock_irqsave(&info->lock, flags);
if (!info->up)
goto out;
dprintk("walking descs\n");
next_rx = info->next_rx;
desc = info->next_rx_desc;
while ((CMDSTS_OWN & (cmdsts = le32_to_cpu(desc[DESC_CMDSTS]))) &&
(cmdsts != CMDSTS_OWN)) {
struct sk_buff *skb;
u32 extsts = le32_to_cpu(desc[DESC_EXTSTS]);
dma_addr_t bufptr = desc_addr_get(desc + DESC_BUFPTR);
dprintk("cmdsts: %08x\n", cmdsts);
dprintk("link: %08x\n", cpu_to_le32(desc[DESC_LINK]));
dprintk("extsts: %08x\n", extsts);
skb = info->skbs[next_rx];
info->skbs[next_rx] = NULL;
info->next_rx = (next_rx + 1) % NR_RX_DESC;
mb();
clear_rx_desc(dev, next_rx);
pci_unmap_single(dev->pci_dev, bufptr,
RX_BUF_SIZE, PCI_DMA_FROMDEVICE);
len = cmdsts & CMDSTS_LEN_MASK;
#ifdef NS83820_VLAN_ACCEL_SUPPORT
/* NH: As was mentioned below, this chip is kinda
* brain dead about vlan tag stripping. Frames
* that are 64 bytes with a vlan header appended
* like arp frames, or pings, are flagged as Runts
* when the tag is stripped and hardware. This
* also means that the OK bit in the descriptor
* is cleared when the frame comes in so we have
* to do a specific length check here to make sure
* the frame would have been ok, had we not stripped
* the tag.
*/
if (likely((CMDSTS_OK & cmdsts) ||
((cmdsts & CMDSTS_RUNT) && len >= 56))) {
#else
if (likely(CMDSTS_OK & cmdsts)) {
#endif
skb_put(skb, len);
if (unlikely(!skb))
goto netdev_mangle_me_harder_failed;
if (cmdsts & CMDSTS_DEST_MULTI)
dev->stats.multicast ++;
dev->stats.rx_packets ++;
dev->stats.rx_bytes += len;
if ((extsts & 0x002a0000) && !(extsts & 0x00540000)) {
skb->ip_summed = CHECKSUM_UNNECESSARY;
} else {
skb->ip_summed = CHECKSUM_NONE;
}
skb->protocol = eth_type_trans(skb, ndev);
#ifdef NS83820_VLAN_ACCEL_SUPPORT
if(extsts & EXTSTS_VPKT) {
unsigned short tag;
tag = ntohs(extsts & EXTSTS_VTG_MASK);
rx_rc = vlan_hwaccel_rx(skb,dev->vlgrp,tag);
} else {
rx_rc = netif_rx(skb);
}
#else
rx_rc = netif_rx(skb);
#endif
if (NET_RX_DROP == rx_rc) {
netdev_mangle_me_harder_failed:
dev->stats.rx_dropped ++;
}
} else {
kfree_skb(skb);
}
nr++;
next_rx = info->next_rx;
desc = info->descs + (DESC_SIZE * next_rx);
}
info->next_rx = next_rx;
info->next_rx_desc = info->descs + (DESC_SIZE * next_rx);
out:
if (0 && !nr) {
Dprintk("dazed: cmdsts_f: %08x\n", cmdsts);
}
spin_unlock_irqrestore(&info->lock, flags);
}
static void rx_action(unsigned long _dev)
{
struct net_device *ndev = (void *)_dev;
struct ns83820 *dev = PRIV(ndev);
rx_irq(ndev);
writel(ihr, dev->base + IHR);
spin_lock_irq(&dev->misc_lock);
dev->IMR_cache |= ISR_RXDESC;
writel(dev->IMR_cache, dev->base + IMR);
spin_unlock_irq(&dev->misc_lock);
rx_irq(ndev);
ns83820_rx_kick(ndev);
}
/* Packet Transmit code
*/
static inline void kick_tx(struct ns83820 *dev)
{
dprintk("kick_tx(%p): tx_idx=%d free_idx=%d\n",
dev, dev->tx_idx, dev->tx_free_idx);
writel(CR_TXE, dev->base + CR);
}
/* No spinlock needed on the transmit irq path as the interrupt handler is
* serialized.
*/
static void do_tx_done(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
u32 cmdsts, tx_done_idx;
__le32 *desc;
dprintk("do_tx_done(%p)\n", ndev);
tx_done_idx = dev->tx_done_idx;
desc = dev->tx_descs + (tx_done_idx * DESC_SIZE);
dprintk("tx_done_idx=%d free_idx=%d cmdsts=%08x\n",
tx_done_idx, dev->tx_free_idx, le32_to_cpu(desc[DESC_CMDSTS]));
while ((tx_done_idx != dev->tx_free_idx) &&
!(CMDSTS_OWN & (cmdsts = le32_to_cpu(desc[DESC_CMDSTS]))) ) {
struct sk_buff *skb;
unsigned len;
dma_addr_t addr;
if (cmdsts & CMDSTS_ERR)
dev->stats.tx_errors ++;
if (cmdsts & CMDSTS_OK)
dev->stats.tx_packets ++;
if (cmdsts & CMDSTS_OK)
dev->stats.tx_bytes += cmdsts & 0xffff;
dprintk("tx_done_idx=%d free_idx=%d cmdsts=%08x\n",
tx_done_idx, dev->tx_free_idx, cmdsts);
skb = dev->tx_skbs[tx_done_idx];
dev->tx_skbs[tx_done_idx] = NULL;
dprintk("done(%p)\n", skb);
len = cmdsts & CMDSTS_LEN_MASK;
addr = desc_addr_get(desc + DESC_BUFPTR);
if (skb) {
pci_unmap_single(dev->pci_dev,
addr,
len,
PCI_DMA_TODEVICE);
dev_kfree_skb_irq(skb);
atomic_dec(&dev->nr_tx_skbs);
} else
pci_unmap_page(dev->pci_dev,
addr,
len,
PCI_DMA_TODEVICE);
tx_done_idx = (tx_done_idx + 1) % NR_TX_DESC;
dev->tx_done_idx = tx_done_idx;
desc[DESC_CMDSTS] = cpu_to_le32(0);
mb();
desc = dev->tx_descs + (tx_done_idx * DESC_SIZE);
}
/* Allow network stack to resume queueing packets after we've
* finished transmitting at least 1/4 of the packets in the queue.
*/
if (netif_queue_stopped(ndev) && start_tx_okay(dev)) {
dprintk("start_queue(%p)\n", ndev);
netif_start_queue(ndev);
netif_wake_queue(ndev);
}
}
static void ns83820_cleanup_tx(struct ns83820 *dev)
{
unsigned i;
for (i=0; i<NR_TX_DESC; i++) {
struct sk_buff *skb = dev->tx_skbs[i];
dev->tx_skbs[i] = NULL;
if (skb) {
__le32 *desc = dev->tx_descs + (i * DESC_SIZE);
pci_unmap_single(dev->pci_dev,
desc_addr_get(desc + DESC_BUFPTR),
le32_to_cpu(desc[DESC_CMDSTS]) & CMDSTS_LEN_MASK,
PCI_DMA_TODEVICE);
dev_kfree_skb_irq(skb);
atomic_dec(&dev->nr_tx_skbs);
}
}
memset(dev->tx_descs, 0, NR_TX_DESC * DESC_SIZE * 4);
}
/* transmit routine. This code relies on the network layer serializing
* its calls in, but will run happily in parallel with the interrupt
* handler. This code currently has provisions for fragmenting tx buffers
* while trying to track down a bug in either the zero copy code or
* the tx fifo (hence the MAX_FRAG_LEN).
*/
static int ns83820_hard_start_xmit(struct sk_buff *skb, struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
u32 free_idx, cmdsts, extsts;
int nr_free, nr_frags;
unsigned tx_done_idx, last_idx;
dma_addr_t buf;
unsigned len;
skb_frag_t *frag;
int stopped = 0;
int do_intr = 0;
volatile __le32 *first_desc;
dprintk("ns83820_hard_start_xmit\n");
nr_frags = skb_shinfo(skb)->nr_frags;
again:
if (unlikely(dev->CFG_cache & CFG_LNKSTS)) {
netif_stop_queue(ndev);
if (unlikely(dev->CFG_cache & CFG_LNKSTS))
return 1;
netif_start_queue(ndev);
}
last_idx = free_idx = dev->tx_free_idx;
tx_done_idx = dev->tx_done_idx;
nr_free = (tx_done_idx + NR_TX_DESC-2 - free_idx) % NR_TX_DESC;
nr_free -= 1;
if (nr_free <= nr_frags) {
dprintk("stop_queue - not enough(%p)\n", ndev);
netif_stop_queue(ndev);
/* Check again: we may have raced with a tx done irq */
if (dev->tx_done_idx != tx_done_idx) {
dprintk("restart queue(%p)\n", ndev);
netif_start_queue(ndev);
goto again;
}
return 1;
}
if (free_idx == dev->tx_intr_idx) {
do_intr = 1;
dev->tx_intr_idx = (dev->tx_intr_idx + NR_TX_DESC/4) % NR_TX_DESC;
}
nr_free -= nr_frags;
if (nr_free < MIN_TX_DESC_FREE) {
dprintk("stop_queue - last entry(%p)\n", ndev);
netif_stop_queue(ndev);
stopped = 1;
}
frag = skb_shinfo(skb)->frags;
if (!nr_frags)
frag = NULL;
extsts = 0;
if (skb->ip_summed == CHECKSUM_PARTIAL) {
extsts |= EXTSTS_IPPKT;
if (IPPROTO_TCP == ip_hdr(skb)->protocol)
extsts |= EXTSTS_TCPPKT;
else if (IPPROTO_UDP == ip_hdr(skb)->protocol)
extsts |= EXTSTS_UDPPKT;
}
#ifdef NS83820_VLAN_ACCEL_SUPPORT
if(vlan_tx_tag_present(skb)) {
/* fetch the vlan tag info out of the
* ancilliary data if the vlan code
* is using hw vlan acceleration
*/
short tag = vlan_tx_tag_get(skb);
extsts |= (EXTSTS_VPKT | htons(tag));
}
#endif
len = skb->len;
if (nr_frags)
len -= skb->data_len;
buf = pci_map_single(dev->pci_dev, skb->data, len, PCI_DMA_TODEVICE);
first_desc = dev->tx_descs + (free_idx * DESC_SIZE);
for (;;) {
volatile __le32 *desc = dev->tx_descs + (free_idx * DESC_SIZE);
dprintk("frag[%3u]: %4u @ 0x%08Lx\n", free_idx, len,
(unsigned long long)buf);
last_idx = free_idx;
free_idx = (free_idx + 1) % NR_TX_DESC;
desc[DESC_LINK] = cpu_to_le32(dev->tx_phy_descs + (free_idx * DESC_SIZE * 4));
desc_addr_set(desc + DESC_BUFPTR, buf);
desc[DESC_EXTSTS] = cpu_to_le32(extsts);
cmdsts = ((nr_frags) ? CMDSTS_MORE : do_intr ? CMDSTS_INTR : 0);
cmdsts |= (desc == first_desc) ? 0 : CMDSTS_OWN;
cmdsts |= len;
desc[DESC_CMDSTS] = cpu_to_le32(cmdsts);
if (!nr_frags)
break;
buf = pci_map_page(dev->pci_dev, frag->page,
frag->page_offset,
frag->size, PCI_DMA_TODEVICE);
dprintk("frag: buf=%08Lx page=%08lx offset=%08lx\n",
(long long)buf, (long) page_to_pfn(frag->page),
frag->page_offset);
len = frag->size;
frag++;
nr_frags--;
}
dprintk("done pkt\n");
spin_lock_irq(&dev->tx_lock);
dev->tx_skbs[last_idx] = skb;
first_desc[DESC_CMDSTS] |= cpu_to_le32(CMDSTS_OWN);
dev->tx_free_idx = free_idx;
atomic_inc(&dev->nr_tx_skbs);
spin_unlock_irq(&dev->tx_lock);
kick_tx(dev);
/* Check again: we may have raced with a tx done irq */
if (stopped && (dev->tx_done_idx != tx_done_idx) && start_tx_okay(dev))
netif_start_queue(ndev);
/* set the transmit start time to catch transmit timeouts */
ndev->trans_start = jiffies;
return 0;
}
static void ns83820_update_stats(struct ns83820 *dev)
{
u8 __iomem *base = dev->base;
/* the DP83820 will freeze counters, so we need to read all of them */
dev->stats.rx_errors += readl(base + 0x60) & 0xffff;
dev->stats.rx_crc_errors += readl(base + 0x64) & 0xffff;
dev->stats.rx_missed_errors += readl(base + 0x68) & 0xffff;
dev->stats.rx_frame_errors += readl(base + 0x6c) & 0xffff;
/*dev->stats.rx_symbol_errors +=*/ readl(base + 0x70);
dev->stats.rx_length_errors += readl(base + 0x74) & 0xffff;
dev->stats.rx_length_errors += readl(base + 0x78) & 0xffff;
/*dev->stats.rx_badopcode_errors += */ readl(base + 0x7c);
/*dev->stats.rx_pause_count += */ readl(base + 0x80);
/*dev->stats.tx_pause_count += */ readl(base + 0x84);
dev->stats.tx_carrier_errors += readl(base + 0x88) & 0xff;
}
static struct net_device_stats *ns83820_get_stats(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
/* somewhat overkill */
spin_lock_irq(&dev->misc_lock);
ns83820_update_stats(dev);
spin_unlock_irq(&dev->misc_lock);
return &dev->stats;
}
/* Let ethtool retrieve info */
static int ns83820_get_settings(struct net_device *ndev,
struct ethtool_cmd *cmd)
{
struct ns83820 *dev = PRIV(ndev);
u32 cfg, tanar, tbicr;
int have_optical = 0;
int fullduplex = 0;
/*
* Here's the list of available ethtool commands from other drivers:
* cmd->advertising =
* cmd->speed =
* cmd->duplex =
* cmd->port = 0;
* cmd->phy_address =
* cmd->transceiver = 0;
* cmd->autoneg =
* cmd->maxtxpkt = 0;
* cmd->maxrxpkt = 0;
*/
/* read current configuration */
cfg = readl(dev->base + CFG) ^ SPDSTS_POLARITY;
tanar = readl(dev->base + TANAR);
tbicr = readl(dev->base + TBICR);
if (dev->CFG_cache & CFG_TBI_EN) {
/* we have an optical interface */
have_optical = 1;
fullduplex = (cfg & CFG_DUPSTS) ? 1 : 0;
} else {
/* We have copper */
fullduplex = (cfg & CFG_DUPSTS) ? 1 : 0;
}
cmd->supported = SUPPORTED_Autoneg;
/* we have optical interface */
if (dev->CFG_cache & CFG_TBI_EN) {
cmd->supported |= SUPPORTED_1000baseT_Half |
SUPPORTED_1000baseT_Full |
SUPPORTED_FIBRE;
cmd->port = PORT_FIBRE;
} /* TODO: else copper related support */
cmd->duplex = fullduplex ? DUPLEX_FULL : DUPLEX_HALF;
switch (cfg / CFG_SPDSTS0 & 3) {
case 2:
cmd->speed = SPEED_1000;
break;
case 1:
cmd->speed = SPEED_100;
break;
default:
cmd->speed = SPEED_10;
break;
}
cmd->autoneg = (tbicr & TBICR_MR_AN_ENABLE) ? 1: 0;
return 0;
}
/* Let ethool change settings*/
static int ns83820_set_settings(struct net_device *ndev,
struct ethtool_cmd *cmd)
{
struct ns83820 *dev = PRIV(ndev);
u32 cfg, tanar;
int have_optical = 0;
int fullduplex = 0;
/* read current configuration */
cfg = readl(dev->base + CFG) ^ SPDSTS_POLARITY;
tanar = readl(dev->base + TANAR);
if (dev->CFG_cache & CFG_TBI_EN) {
/* we have optical */
have_optical = 1;
fullduplex = (tanar & TANAR_FULL_DUP);
} else {
/* we have copper */
fullduplex = cfg & CFG_DUPSTS;
}
spin_lock_irq(&dev->misc_lock);
spin_lock(&dev->tx_lock);
/* Set duplex */
if (cmd->duplex != fullduplex) {
if (have_optical) {
/*set full duplex*/
if (cmd->duplex == DUPLEX_FULL) {
/* force full duplex */
writel(readl(dev->base + TXCFG)
| TXCFG_CSI | TXCFG_HBI | TXCFG_ATP,
dev->base + TXCFG);
writel(readl(dev->base + RXCFG) | RXCFG_RX_FD,
dev->base + RXCFG);
/* Light up full duplex LED */
writel(readl(dev->base + GPIOR) | GPIOR_GP1_OUT,
dev->base + GPIOR);
} else {
/*TODO: set half duplex */
}
} else {
/*we have copper*/
/* TODO: Set duplex for copper cards */
}
printk(KERN_INFO "%s: Duplex set via ethtool\n",
ndev->name);
}
/* Set autonegotiation */
if (1) {
if (cmd->autoneg == AUTONEG_ENABLE) {
/* restart auto negotiation */
writel(TBICR_MR_AN_ENABLE | TBICR_MR_RESTART_AN,
dev->base + TBICR);
writel(TBICR_MR_AN_ENABLE, dev->base + TBICR);
dev->linkstate = LINK_AUTONEGOTIATE;
printk(KERN_INFO "%s: autoneg enabled via ethtool\n",
ndev->name);
} else {
/* disable auto negotiation */
writel(0x00000000, dev->base + TBICR);
}
printk(KERN_INFO "%s: autoneg %s via ethtool\n", ndev->name,
cmd->autoneg ? "ENABLED" : "DISABLED");
}
phy_intr(ndev);
spin_unlock(&dev->tx_lock);
spin_unlock_irq(&dev->misc_lock);
return 0;
}
/* end ethtool get/set support -df */
static void ns83820_get_drvinfo(struct net_device *ndev, struct ethtool_drvinfo *info)
{
struct ns83820 *dev = PRIV(ndev);
strcpy(info->driver, "ns83820");
strcpy(info->version, VERSION);
strcpy(info->bus_info, pci_name(dev->pci_dev));
}
static u32 ns83820_get_link(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
u32 cfg = readl(dev->base + CFG) ^ SPDSTS_POLARITY;
return cfg & CFG_LNKSTS ? 1 : 0;
}
static const struct ethtool_ops ops = {
.get_settings = ns83820_get_settings,
.set_settings = ns83820_set_settings,
.get_drvinfo = ns83820_get_drvinfo,
.get_link = ns83820_get_link
};
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
/* this function is called in irq context from the ISR */
static void ns83820_mib_isr(struct ns83820 *dev)
{
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
unsigned long flags;
spin_lock_irqsave(&dev->misc_lock, flags);
ns83820_update_stats(dev);
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
spin_unlock_irqrestore(&dev->misc_lock, flags);
}
static void ns83820_do_isr(struct net_device *ndev, u32 isr);
IRQ: Maintain regs pointer globally rather than passing to IRQ handlers Maintain a per-CPU global "struct pt_regs *" variable which can be used instead of passing regs around manually through all ~1800 interrupt handlers in the Linux kernel. The regs pointer is used in few places, but it potentially costs both stack space and code to pass it around. On the FRV arch, removing the regs parameter from all the genirq function results in a 20% speed up of the IRQ exit path (ie: from leaving timer_interrupt() to leaving do_IRQ()). Where appropriate, an arch may override the generic storage facility and do something different with the variable. On FRV, for instance, the address is maintained in GR28 at all times inside the kernel as part of general exception handling. Having looked over the code, it appears that the parameter may be handed down through up to twenty or so layers of functions. Consider a USB character device attached to a USB hub, attached to a USB controller that posts its interrupts through a cascaded auxiliary interrupt controller. A character device driver may want to pass regs to the sysrq handler through the input layer which adds another few layers of parameter passing. I've build this code with allyesconfig for x86_64 and i386. I've runtested the main part of the code on FRV and i386, though I can't test most of the drivers. I've also done partial conversion for powerpc and MIPS - these at least compile with minimal configurations. This will affect all archs. Mostly the changes should be relatively easy. Take do_IRQ(), store the regs pointer at the beginning, saving the old one: struct pt_regs *old_regs = set_irq_regs(regs); And put the old one back at the end: set_irq_regs(old_regs); Don't pass regs through to generic_handle_irq() or __do_IRQ(). In timer_interrupt(), this sort of change will be necessary: - update_process_times(user_mode(regs)); - profile_tick(CPU_PROFILING, regs); + update_process_times(user_mode(get_irq_regs())); + profile_tick(CPU_PROFILING); I'd like to move update_process_times()'s use of get_irq_regs() into itself, except that i386, alone of the archs, uses something other than user_mode(). Some notes on the interrupt handling in the drivers: (*) input_dev() is now gone entirely. The regs pointer is no longer stored in the input_dev struct. (*) finish_unlinks() in drivers/usb/host/ohci-q.c needs checking. It does something different depending on whether it's been supplied with a regs pointer or not. (*) Various IRQ handler function pointers have been moved to type irq_handler_t. Signed-Off-By: David Howells <dhowells@redhat.com> (cherry picked from 1b16e7ac850969f38b375e511e3fa2f474a33867 commit)
2006-10-05 06:55:46 -07:00
static irqreturn_t ns83820_irq(int foo, void *data)
{
struct net_device *ndev = data;
struct ns83820 *dev = PRIV(ndev);
u32 isr;
dprintk("ns83820_irq(%p)\n", ndev);
dev->ihr = 0;
isr = readl(dev->base + ISR);
dprintk("irq: %08x\n", isr);
ns83820_do_isr(ndev, isr);
return IRQ_HANDLED;
}
static void ns83820_do_isr(struct net_device *ndev, u32 isr)
{
struct ns83820 *dev = PRIV(ndev);
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
unsigned long flags;
#ifdef DEBUG
if (isr & ~(ISR_PHY | ISR_RXDESC | ISR_RXEARLY | ISR_RXOK | ISR_RXERR | ISR_TXIDLE | ISR_TXOK | ISR_TXDESC))
Dprintk("odd isr? 0x%08x\n", isr);
#endif
if (ISR_RXIDLE & isr) {
dev->rx_info.idle = 1;
Dprintk("oh dear, we are idle\n");
ns83820_rx_kick(ndev);
}
if ((ISR_RXDESC | ISR_RXOK) & isr) {
prefetch(dev->rx_info.next_rx_desc);
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
spin_lock_irqsave(&dev->misc_lock, flags);
dev->IMR_cache &= ~(ISR_RXDESC | ISR_RXOK);
writel(dev->IMR_cache, dev->base + IMR);
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
spin_unlock_irqrestore(&dev->misc_lock, flags);
tasklet_schedule(&dev->rx_tasklet);
//rx_irq(ndev);
//writel(4, dev->base + IHR);
}
if ((ISR_RXIDLE | ISR_RXORN | ISR_RXDESC | ISR_RXOK | ISR_RXERR) & isr)
ns83820_rx_kick(ndev);
if (unlikely(ISR_RXSOVR & isr)) {
//printk("overrun: rxsovr\n");
dev->stats.rx_fifo_errors ++;
}
if (unlikely(ISR_RXORN & isr)) {
//printk("overrun: rxorn\n");
dev->stats.rx_fifo_errors ++;
}
if ((ISR_RXRCMP & isr) && dev->rx_info.up)
writel(CR_RXE, dev->base + CR);
if (ISR_TXIDLE & isr) {
u32 txdp;
txdp = readl(dev->base + TXDP);
dprintk("txdp: %08x\n", txdp);
txdp -= dev->tx_phy_descs;
dev->tx_idx = txdp / (DESC_SIZE * 4);
if (dev->tx_idx >= NR_TX_DESC) {
printk(KERN_ALERT "%s: BUG -- txdp out of range\n", ndev->name);
dev->tx_idx = 0;
}
/* The may have been a race between a pci originated read
* and the descriptor update from the cpu. Just in case,
* kick the transmitter if the hardware thinks it is on a
* different descriptor than we are.
*/
if (dev->tx_idx != dev->tx_free_idx)
kick_tx(dev);
}
/* Defer tx ring processing until more than a minimum amount of
* work has accumulated
*/
if ((ISR_TXDESC | ISR_TXIDLE | ISR_TXOK | ISR_TXERR) & isr) {
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
spin_lock_irqsave(&dev->tx_lock, flags);
do_tx_done(ndev);
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
spin_unlock_irqrestore(&dev->tx_lock, flags);
/* Disable TxOk if there are no outstanding tx packets.
*/
if ((dev->tx_done_idx == dev->tx_free_idx) &&
(dev->IMR_cache & ISR_TXOK)) {
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
spin_lock_irqsave(&dev->misc_lock, flags);
dev->IMR_cache &= ~ISR_TXOK;
writel(dev->IMR_cache, dev->base + IMR);
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
spin_unlock_irqrestore(&dev->misc_lock, flags);
}
}
/* The TxIdle interrupt can come in before the transmit has
* completed. Normally we reap packets off of the combination
* of TxDesc and TxIdle and leave TxOk disabled (since it
* occurs on every packet), but when no further irqs of this
* nature are expected, we must enable TxOk.
*/
if ((ISR_TXIDLE & isr) && (dev->tx_done_idx != dev->tx_free_idx)) {
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
spin_lock_irqsave(&dev->misc_lock, flags);
dev->IMR_cache |= ISR_TXOK;
writel(dev->IMR_cache, dev->base + IMR);
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
spin_unlock_irqrestore(&dev->misc_lock, flags);
}
/* MIB interrupt: one of the statistics counters is about to overflow */
if (unlikely(ISR_MIB & isr))
ns83820_mib_isr(dev);
/* PHY: Link up/down/negotiation state change */
if (unlikely(ISR_PHY & isr))
phy_intr(ndev);
#if 0 /* Still working on the interrupt mitigation strategy */
if (dev->ihr)
writel(dev->ihr, dev->base + IHR);
#endif
}
static void ns83820_do_reset(struct ns83820 *dev, u32 which)
{
Dprintk("resetting chip...\n");
writel(which, dev->base + CR);
do {
schedule();
} while (readl(dev->base + CR) & which);
Dprintk("okay!\n");
}
static int ns83820_stop(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
/* FIXME: protect against interrupt handler? */
del_timer_sync(&dev->tx_watchdog);
/* disable interrupts */
writel(0, dev->base + IMR);
writel(0, dev->base + IER);
readl(dev->base + IER);
dev->rx_info.up = 0;
synchronize_irq(dev->pci_dev->irq);
ns83820_do_reset(dev, CR_RST);
synchronize_irq(dev->pci_dev->irq);
spin_lock_irq(&dev->misc_lock);
dev->IMR_cache &= ~(ISR_TXURN | ISR_TXIDLE | ISR_TXERR | ISR_TXDESC | ISR_TXOK);
spin_unlock_irq(&dev->misc_lock);
ns83820_cleanup_rx(dev);
ns83820_cleanup_tx(dev);
return 0;
}
static void ns83820_tx_timeout(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
u32 tx_done_idx;
__le32 *desc;
unsigned long flags;
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
spin_lock_irqsave(&dev->tx_lock, flags);
tx_done_idx = dev->tx_done_idx;
desc = dev->tx_descs + (tx_done_idx * DESC_SIZE);
printk(KERN_INFO "%s: tx_timeout: tx_done_idx=%d free_idx=%d cmdsts=%08x\n",
ndev->name,
tx_done_idx, dev->tx_free_idx, le32_to_cpu(desc[DESC_CMDSTS]));
#if defined(DEBUG)
{
u32 isr;
isr = readl(dev->base + ISR);
printk("irq: %08x imr: %08x\n", isr, dev->IMR_cache);
ns83820_do_isr(ndev, isr);
}
#endif
do_tx_done(ndev);
tx_done_idx = dev->tx_done_idx;
desc = dev->tx_descs + (tx_done_idx * DESC_SIZE);
printk(KERN_INFO "%s: after: tx_done_idx=%d free_idx=%d cmdsts=%08x\n",
ndev->name,
tx_done_idx, dev->tx_free_idx, le32_to_cpu(desc[DESC_CMDSTS]));
[PATCH] lock validator: fix ns83820.c irq-flags bug Barry K. Nathan reported the following lockdep warning: [ 197.343948] BUG: warning at kernel/lockdep.c:1856/trace_hardirqs_on() [ 197.345928] [<c010329b>] show_trace_log_lvl+0x5b/0x105 [ 197.346359] [<c0103896>] show_trace+0x1b/0x20 [ 197.346759] [<c01038ed>] dump_stack+0x1f/0x24 [ 197.347159] [<c012efa2>] trace_hardirqs_on+0xfb/0x185 [ 197.348873] [<c029b009>] _spin_unlock_irq+0x24/0x2d [ 197.350620] [<e09034e8>] do_tx_done+0x171/0x179 [ns83820] [ 197.350895] [<e090445c>] ns83820_irq+0x149/0x20b [ns83820] [ 197.351166] [<c013b4b8>] handle_IRQ_event+0x1d/0x52 [ 197.353216] [<c013c6c2>] handle_level_irq+0x97/0xe1 [ 197.355157] [<c01048c3>] do_IRQ+0x8b/0xac [ 197.355612] [<c0102d9d>] common_interrupt+0x25/0x2c this is caused because the ns83820 driver re-enables irq flags in hardirq context. While legal in theory, in practice it should only be done if the hardware is really old and has some very high overhead in its ISR. (such as PIO IDE) For modern hardware, running ISRs with irqs enabled is discouraged, because 1) new hardware is fast enough to not cause latency problems 2) allowing the nesting of hardware interrupts only 'spreads out' the handling of the current ISR, causing extra cachemisses that would otherwise not happen. Furthermore, on architectures where ISRs share the kernel stacks, enabling interrupts in ISRs introduces a much higher kernel-stack-nesting and thus kernel-stack-overflow risk. 3) not managing irq-flags via the _irqsave / _irqrestore variants is dangerous: it's easy to forget whether one function nests inside another, and irq flags might be mismanaged. In the few cases where re-enabling interrupts in an ISR is considered useful (and unavoidable), it has to be taught to the lock validator explicitly (because the lock validator needs the "no ISR ever enables hardirqs" artificial simplification to keep the IRQ/softirq locking dependencies manageable). This teaching is done via the explicit use local_irq_enable_in_hardirq(). On a stock kernel this maps to local_irq_enable(). If the lock validator is enabled then this does not enable interrupts. Now, the analysis of drivers/net/ns83820.c's irq flags use: the irq-enabling in irq context seems intentional, but i dont think it's justified. Furthermore, the driver suffers from problem #3 above too, in ns83820_tx_timeout() it disables irqs via local_irq_save(), but then it calls do_tx_done() which does a spin_unlock_irq(), re-enabling for a function that does not expect it! While currently this bug seems harmless (only some debug printout seems to be affected by it), it's nevertheless something to be fixed. So this patch makes the ns83820 ISR irq-flags-safe, and cleans up do_tx_done() use and locking to avoid the ns83820_tx_timeout() bug. From: Arjan van de Ven <arjan@linux.intel.com> ns83820_mib_isr takes the misc_lock in IRQ context. All other places that do this in the ISR already use _irqsave versions, make this consistent at least. At some point in the future someone should audit the driver to see if all _irqsave's in the ISR can go away, this is generally an iffy/fragile proposition though; for now get it safe, simple and consistent. From: Arjan van de Ven <arjan@linux.intel.com> ok this is a real driver deadlock: The ns83820 driver enabled interrupts (by unlocking the misc_lock with _irq) while still holding the rx_info.lock, which is required to be irq safe since it's used in the ISR like this: writel(1, dev->base + IER); spin_unlock_irq(&dev->misc_lock); kick_rx(ndev); spin_unlock_irq(&dev->rx_info.lock); This is can cause a deadlock if an irq was pending at the first spin_unlock_irq already, or if one would hit during kick_rx(). Simply remove the first _irq solves this Signed-off-by: Ingo Molnar <mingo@elte.hu> Cc: Benjamin LaHaise <bcrl@kvack.org> Cc: Jeff Garzik <jeff@garzik.org> Signed-off-by: Arjan van de Ven <arjan@linux.intel.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Jeff Garzik <jeff@garzik.org>
2006-06-30 02:25:06 -07:00
spin_unlock_irqrestore(&dev->tx_lock, flags);
}
static void ns83820_tx_watch(unsigned long data)
{
struct net_device *ndev = (void *)data;
struct ns83820 *dev = PRIV(ndev);
#if defined(DEBUG)
printk("ns83820_tx_watch: %u %u %d\n",
dev->tx_done_idx, dev->tx_free_idx, atomic_read(&dev->nr_tx_skbs)
);
#endif
if (time_after(jiffies, ndev->trans_start + 1*HZ) &&
dev->tx_done_idx != dev->tx_free_idx) {
printk(KERN_DEBUG "%s: ns83820_tx_watch: %u %u %d\n",
ndev->name,
dev->tx_done_idx, dev->tx_free_idx,
atomic_read(&dev->nr_tx_skbs));
ns83820_tx_timeout(ndev);
}
mod_timer(&dev->tx_watchdog, jiffies + 2*HZ);
}
static int ns83820_open(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
unsigned i;
u32 desc;
int ret;
dprintk("ns83820_open\n");
writel(0, dev->base + PQCR);
ret = ns83820_setup_rx(ndev);
if (ret)
goto failed;
memset(dev->tx_descs, 0, 4 * NR_TX_DESC * DESC_SIZE);
for (i=0; i<NR_TX_DESC; i++) {
dev->tx_descs[(i * DESC_SIZE) + DESC_LINK]
= cpu_to_le32(
dev->tx_phy_descs
+ ((i+1) % NR_TX_DESC) * DESC_SIZE * 4);
}
dev->tx_idx = 0;
dev->tx_done_idx = 0;
desc = dev->tx_phy_descs;
writel(0, dev->base + TXDP_HI);
writel(desc, dev->base + TXDP);
init_timer(&dev->tx_watchdog);
dev->tx_watchdog.data = (unsigned long)ndev;
dev->tx_watchdog.function = ns83820_tx_watch;
mod_timer(&dev->tx_watchdog, jiffies + 2*HZ);
netif_start_queue(ndev); /* FIXME: wait for phy to come up */
return 0;
failed:
ns83820_stop(ndev);
return ret;
}
static void ns83820_getmac(struct ns83820 *dev, u8 *mac)
{
unsigned i;
for (i=0; i<3; i++) {
u32 data;
/* Read from the perfect match memory: this is loaded by
* the chip from the EEPROM via the EELOAD self test.
*/
writel(i*2, dev->base + RFCR);
data = readl(dev->base + RFDR);
*mac++ = data;
*mac++ = data >> 8;
}
}
static int ns83820_change_mtu(struct net_device *ndev, int new_mtu)
{
if (new_mtu > RX_BUF_SIZE)
return -EINVAL;
ndev->mtu = new_mtu;
return 0;
}
static void ns83820_set_multicast(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
u8 __iomem *rfcr = dev->base + RFCR;
u32 and_mask = 0xffffffff;
u32 or_mask = 0;
u32 val;
if (ndev->flags & IFF_PROMISC)
or_mask |= RFCR_AAU | RFCR_AAM;
else
and_mask &= ~(RFCR_AAU | RFCR_AAM);
if (ndev->flags & IFF_ALLMULTI || ndev->mc_count)
or_mask |= RFCR_AAM;
else
and_mask &= ~RFCR_AAM;
spin_lock_irq(&dev->misc_lock);
val = (readl(rfcr) & and_mask) | or_mask;
/* Ramit : RFCR Write Fix doc says RFEN must be 0 modify other bits */
writel(val & ~RFCR_RFEN, rfcr);
writel(val, rfcr);
spin_unlock_irq(&dev->misc_lock);
}
static void ns83820_run_bist(struct net_device *ndev, const char *name, u32 enable, u32 done, u32 fail)
{
struct ns83820 *dev = PRIV(ndev);
int timed_out = 0;
unsigned long start;
u32 status;
int loops = 0;
dprintk("%s: start %s\n", ndev->name, name);
start = jiffies;
writel(enable, dev->base + PTSCR);
for (;;) {
loops++;
status = readl(dev->base + PTSCR);
if (!(status & enable))
break;
if (status & done)
break;
if (status & fail)
break;
if (time_after_eq(jiffies, start + HZ)) {
timed_out = 1;
break;
}
schedule_timeout_uninterruptible(1);
}
if (status & fail)
printk(KERN_INFO "%s: %s failed! (0x%08x & 0x%08x)\n",
ndev->name, name, status, fail);
else if (timed_out)
printk(KERN_INFO "%s: run_bist %s timed out! (%08x)\n",
ndev->name, name, status);
dprintk("%s: done %s in %d loops\n", ndev->name, name, loops);
}
#ifdef PHY_CODE_IS_FINISHED
static void ns83820_mii_write_bit(struct ns83820 *dev, int bit)
{
/* drive MDC low */
dev->MEAR_cache &= ~MEAR_MDC;
writel(dev->MEAR_cache, dev->base + MEAR);
readl(dev->base + MEAR);
/* enable output, set bit */
dev->MEAR_cache |= MEAR_MDDIR;
if (bit)
dev->MEAR_cache |= MEAR_MDIO;
else
dev->MEAR_cache &= ~MEAR_MDIO;
/* set the output bit */
writel(dev->MEAR_cache, dev->base + MEAR);
readl(dev->base + MEAR);
/* Wait. Max clock rate is 2.5MHz, this way we come in under 1MHz */
udelay(1);
/* drive MDC high causing the data bit to be latched */
dev->MEAR_cache |= MEAR_MDC;
writel(dev->MEAR_cache, dev->base + MEAR);
readl(dev->base + MEAR);
/* Wait again... */
udelay(1);
}
static int ns83820_mii_read_bit(struct ns83820 *dev)
{
int bit;
/* drive MDC low, disable output */
dev->MEAR_cache &= ~MEAR_MDC;
dev->MEAR_cache &= ~MEAR_MDDIR;
writel(dev->MEAR_cache, dev->base + MEAR);
readl(dev->base + MEAR);
/* Wait. Max clock rate is 2.5MHz, this way we come in under 1MHz */
udelay(1);
/* drive MDC high causing the data bit to be latched */
bit = (readl(dev->base + MEAR) & MEAR_MDIO) ? 1 : 0;
dev->MEAR_cache |= MEAR_MDC;
writel(dev->MEAR_cache, dev->base + MEAR);
/* Wait again... */
udelay(1);
return bit;
}
static unsigned ns83820_mii_read_reg(struct ns83820 *dev, unsigned phy, unsigned reg)
{
unsigned data = 0;
int i;
/* read some garbage so that we eventually sync up */
for (i=0; i<64; i++)
ns83820_mii_read_bit(dev);
ns83820_mii_write_bit(dev, 0); /* start */
ns83820_mii_write_bit(dev, 1);
ns83820_mii_write_bit(dev, 1); /* opcode read */
ns83820_mii_write_bit(dev, 0);
/* write out the phy address: 5 bits, msb first */
for (i=0; i<5; i++)
ns83820_mii_write_bit(dev, phy & (0x10 >> i));
/* write out the register address, 5 bits, msb first */
for (i=0; i<5; i++)
ns83820_mii_write_bit(dev, reg & (0x10 >> i));
ns83820_mii_read_bit(dev); /* turn around cycles */
ns83820_mii_read_bit(dev);
/* read in the register data, 16 bits msb first */
for (i=0; i<16; i++) {
data <<= 1;
data |= ns83820_mii_read_bit(dev);
}
return data;
}
static unsigned ns83820_mii_write_reg(struct ns83820 *dev, unsigned phy, unsigned reg, unsigned data)
{
int i;
/* read some garbage so that we eventually sync up */
for (i=0; i<64; i++)
ns83820_mii_read_bit(dev);
ns83820_mii_write_bit(dev, 0); /* start */
ns83820_mii_write_bit(dev, 1);
ns83820_mii_write_bit(dev, 0); /* opcode read */
ns83820_mii_write_bit(dev, 1);
/* write out the phy address: 5 bits, msb first */
for (i=0; i<5; i++)
ns83820_mii_write_bit(dev, phy & (0x10 >> i));
/* write out the register address, 5 bits, msb first */
for (i=0; i<5; i++)
ns83820_mii_write_bit(dev, reg & (0x10 >> i));
ns83820_mii_read_bit(dev); /* turn around cycles */
ns83820_mii_read_bit(dev);
/* read in the register data, 16 bits msb first */
for (i=0; i<16; i++)
ns83820_mii_write_bit(dev, (data >> (15 - i)) & 1);
return data;
}
static void ns83820_probe_phy(struct net_device *ndev)
{
struct ns83820 *dev = PRIV(ndev);
static int first;
int i;
#define MII_PHYIDR1 0x02
#define MII_PHYIDR2 0x03
#if 0
if (!first) {
unsigned tmp;
ns83820_mii_read_reg(dev, 1, 0x09);
ns83820_mii_write_reg(dev, 1, 0x10, 0x0d3e);
tmp = ns83820_mii_read_reg(dev, 1, 0x00);
ns83820_mii_write_reg(dev, 1, 0x00, tmp | 0x8000);
udelay(1300);
ns83820_mii_read_reg(dev, 1, 0x09);
}
#endif
first = 1;
for (i=1; i<2; i++) {
int j;
unsigned a, b;
a = ns83820_mii_read_reg(dev, i, MII_PHYIDR1);
b = ns83820_mii_read_reg(dev, i, MII_PHYIDR2);
//printk("%s: phy %d: 0x%04x 0x%04x\n",
// ndev->name, i, a, b);
for (j=0; j<0x16; j+=4) {
dprintk("%s: [0x%02x] %04x %04x %04x %04x\n",
ndev->name, j,
ns83820_mii_read_reg(dev, i, 0 + j),
ns83820_mii_read_reg(dev, i, 1 + j),
ns83820_mii_read_reg(dev, i, 2 + j),
ns83820_mii_read_reg(dev, i, 3 + j)
);
}
}
{
unsigned a, b;
/* read firmware version: memory addr is 0x8402 and 0x8403 */
ns83820_mii_write_reg(dev, 1, 0x16, 0x000d);
ns83820_mii_write_reg(dev, 1, 0x1e, 0x810e);
a = ns83820_mii_read_reg(dev, 1, 0x1d);
ns83820_mii_write_reg(dev, 1, 0x16, 0x000d);
ns83820_mii_write_reg(dev, 1, 0x1e, 0x810e);
b = ns83820_mii_read_reg(dev, 1, 0x1d);
dprintk("version: 0x%04x 0x%04x\n", a, b);
}
}
#endif
static int __devinit ns83820_init_one(struct pci_dev *pci_dev, const struct pci_device_id *id)
{
struct net_device *ndev;
struct ns83820 *dev;
long addr;
int err;
int using_dac = 0;
DECLARE_MAC_BUF(mac);
/* See if we can set the dma mask early on; failure is fatal. */
if (sizeof(dma_addr_t) == 8 &&
!pci_set_dma_mask(pci_dev, DMA_64BIT_MASK)) {
using_dac = 1;
} else if (!pci_set_dma_mask(pci_dev, DMA_32BIT_MASK)) {
using_dac = 0;
} else {
dev_warn(&pci_dev->dev, "pci_set_dma_mask failed!\n");
return -ENODEV;
}
ndev = alloc_etherdev(sizeof(struct ns83820));
dev = PRIV(ndev);
err = -ENOMEM;
if (!dev)
goto out;
dev->ndev = ndev;
spin_lock_init(&dev->rx_info.lock);
spin_lock_init(&dev->tx_lock);
spin_lock_init(&dev->misc_lock);
dev->pci_dev = pci_dev;
SET_NETDEV_DEV(ndev, &pci_dev->dev);
INIT_WORK(&dev->tq_refill, queue_refill);
tasklet_init(&dev->rx_tasklet, rx_action, (unsigned long)ndev);
err = pci_enable_device(pci_dev);
if (err) {
dev_info(&pci_dev->dev, "pci_enable_dev failed: %d\n", err);
goto out_free;
}
pci_set_master(pci_dev);
addr = pci_resource_start(pci_dev, 1);
dev->base = ioremap_nocache(addr, PAGE_SIZE);
dev->tx_descs = pci_alloc_consistent(pci_dev,
4 * DESC_SIZE * NR_TX_DESC, &dev->tx_phy_descs);
dev->rx_info.descs = pci_alloc_consistent(pci_dev,
4 * DESC_SIZE * NR_RX_DESC, &dev->rx_info.phy_descs);
err = -ENOMEM;
if (!dev->base || !dev->tx_descs || !dev->rx_info.descs)
goto out_disable;
dprintk("%p: %08lx %p: %08lx\n",
dev->tx_descs, (long)dev->tx_phy_descs,
dev->rx_info.descs, (long)dev->rx_info.phy_descs);
/* disable interrupts */
writel(0, dev->base + IMR);
writel(0, dev->base + IER);
readl(dev->base + IER);
dev->IMR_cache = 0;
err = request_irq(pci_dev->irq, ns83820_irq, IRQF_SHARED,
DRV_NAME, ndev);
if (err) {
dev_info(&pci_dev->dev, "unable to register irq %d, err %d\n",
pci_dev->irq, err);
goto out_disable;
}
/*
* FIXME: we are holding rtnl_lock() over obscenely long area only
* because some of the setup code uses dev->name. It's Wrong(tm) -
* we should be using driver-specific names for all that stuff.
* For now that will do, but we really need to come back and kill
* most of the dev_alloc_name() users later.
*/
rtnl_lock();
err = dev_alloc_name(ndev, ndev->name);
if (err < 0) {
dev_info(&pci_dev->dev, "unable to get netdev name: %d\n", err);
goto out_free_irq;
}
printk("%s: ns83820.c: 0x22c: %08x, subsystem: %04x:%04x\n",
ndev->name, le32_to_cpu(readl(dev->base + 0x22c)),
pci_dev->subsystem_vendor, pci_dev->subsystem_device);
ndev->open = ns83820_open;
ndev->stop = ns83820_stop;
ndev->hard_start_xmit = ns83820_hard_start_xmit;
ndev->get_stats = ns83820_get_stats;
ndev->change_mtu = ns83820_change_mtu;
ndev->set_multicast_list = ns83820_set_multicast;
SET_ETHTOOL_OPS(ndev, &ops);
ndev->tx_timeout = ns83820_tx_timeout;
ndev->watchdog_timeo = 5 * HZ;
pci_set_drvdata(pci_dev, ndev);
ns83820_do_reset(dev, CR_RST);
/* Must reset the ram bist before running it */
writel(PTSCR_RBIST_RST, dev->base + PTSCR);
ns83820_run_bist(ndev, "sram bist", PTSCR_RBIST_EN,
PTSCR_RBIST_DONE, PTSCR_RBIST_FAIL);
ns83820_run_bist(ndev, "eeprom bist", PTSCR_EEBIST_EN, 0,
PTSCR_EEBIST_FAIL);
ns83820_run_bist(ndev, "eeprom load", PTSCR_EELOAD_EN, 0, 0);
/* I love config registers */
dev->CFG_cache = readl(dev->base + CFG);
if ((dev->CFG_cache & CFG_PCI64_DET)) {
printk(KERN_INFO "%s: detected 64 bit PCI data bus.\n",
ndev->name);
/*dev->CFG_cache |= CFG_DATA64_EN;*/
if (!(dev->CFG_cache & CFG_DATA64_EN))
printk(KERN_INFO "%s: EEPROM did not enable 64 bit bus. Disabled.\n",
ndev->name);
} else
dev->CFG_cache &= ~(CFG_DATA64_EN);
dev->CFG_cache &= (CFG_TBI_EN | CFG_MRM_DIS | CFG_MWI_DIS |
CFG_T64ADDR | CFG_DATA64_EN | CFG_EXT_125 |
CFG_M64ADDR);
dev->CFG_cache |= CFG_PINT_DUPSTS | CFG_PINT_LNKSTS | CFG_PINT_SPDSTS |
CFG_EXTSTS_EN | CFG_EXD | CFG_PESEL;
dev->CFG_cache |= CFG_REQALG;
dev->CFG_cache |= CFG_POW;
dev->CFG_cache |= CFG_TMRTEST;
/* When compiled with 64 bit addressing, we must always enable
* the 64 bit descriptor format.
*/
if (sizeof(dma_addr_t) == 8)
dev->CFG_cache |= CFG_M64ADDR;
if (using_dac)
dev->CFG_cache |= CFG_T64ADDR;
/* Big endian mode does not seem to do what the docs suggest */
dev->CFG_cache &= ~CFG_BEM;
/* setup optical transceiver if we have one */
if (dev->CFG_cache & CFG_TBI_EN) {
printk(KERN_INFO "%s: enabling optical transceiver\n",
ndev->name);
writel(readl(dev->base + GPIOR) | 0x3e8, dev->base + GPIOR);
/* setup auto negotiation feature advertisement */
writel(readl(dev->base + TANAR)
| TANAR_HALF_DUP | TANAR_FULL_DUP,
dev->base + TANAR);
/* start auto negotiation */
writel(TBICR_MR_AN_ENABLE | TBICR_MR_RESTART_AN,
dev->base + TBICR);
writel(TBICR_MR_AN_ENABLE, dev->base + TBICR);
dev->linkstate = LINK_AUTONEGOTIATE;
dev->CFG_cache |= CFG_MODE_1000;
}
writel(dev->CFG_cache, dev->base + CFG);
dprintk("CFG: %08x\n", dev->CFG_cache);
if (reset_phy) {
printk(KERN_INFO "%s: resetting phy\n", ndev->name);
writel(dev->CFG_cache | CFG_PHY_RST, dev->base + CFG);
msleep(10);
writel(dev->CFG_cache, dev->base + CFG);
}
#if 0 /* Huh? This sets the PCI latency register. Should be done via
* the PCI layer. FIXME.
*/
if (readl(dev->base + SRR))
writel(readl(dev->base+0x20c) | 0xfe00, dev->base + 0x20c);
#endif
/* Note! The DMA burst size interacts with packet
* transmission, such that the largest packet that
* can be transmitted is 8192 - FLTH - burst size.
* If only the transmit fifo was larger...
*/
/* Ramit : 1024 DMA is not a good idea, it ends up banging
* some DELL and COMPAQ SMP systems */
writel(TXCFG_CSI | TXCFG_HBI | TXCFG_ATP | TXCFG_MXDMA512
| ((1600 / 32) * 0x100),
dev->base + TXCFG);
/* Flush the interrupt holdoff timer */
writel(0x000, dev->base + IHR);
writel(0x100, dev->base + IHR);
writel(0x000, dev->base + IHR);
/* Set Rx to full duplex, don't accept runt, errored, long or length
* range errored packets. Use 512 byte DMA.
*/
/* Ramit : 1024 DMA is not a good idea, it ends up banging
* some DELL and COMPAQ SMP systems
* Turn on ALP, only we are accpeting Jumbo Packets */
writel(RXCFG_AEP | RXCFG_ARP | RXCFG_AIRL | RXCFG_RX_FD
| RXCFG_STRIPCRC
//| RXCFG_ALP
| (RXCFG_MXDMA512) | 0, dev->base + RXCFG);
/* Disable priority queueing */
writel(0, dev->base + PQCR);
/* Enable IP checksum validation and detetion of VLAN headers.
* Note: do not set the reject options as at least the 0x102
* revision of the chip does not properly accept IP fragments
* at least for UDP.
*/
/* Ramit : Be sure to turn on RXCFG_ARP if VLAN's are enabled, since
* the MAC it calculates the packetsize AFTER stripping the VLAN
* header, and if a VLAN Tagged packet of 64 bytes is received (like
* a ping with a VLAN header) then the card, strips the 4 byte VLAN
* tag and then checks the packet size, so if RXCFG_ARP is not enabled,
* it discrards it!. These guys......
* also turn on tag stripping if hardware acceleration is enabled
*/
#ifdef NS83820_VLAN_ACCEL_SUPPORT
#define VRCR_INIT_VALUE (VRCR_IPEN|VRCR_VTDEN|VRCR_VTREN)
#else
#define VRCR_INIT_VALUE (VRCR_IPEN|VRCR_VTDEN)
#endif
writel(VRCR_INIT_VALUE, dev->base + VRCR);
/* Enable per-packet TCP/UDP/IP checksumming
* and per packet vlan tag insertion if
* vlan hardware acceleration is enabled
*/
#ifdef NS83820_VLAN_ACCEL_SUPPORT
#define VTCR_INIT_VALUE (VTCR_PPCHK|VTCR_VPPTI)
#else
#define VTCR_INIT_VALUE VTCR_PPCHK
#endif
writel(VTCR_INIT_VALUE, dev->base + VTCR);
/* Ramit : Enable async and sync pause frames */
/* writel(0, dev->base + PCR); */
writel((PCR_PS_MCAST | PCR_PS_DA | PCR_PSEN | PCR_FFLO_4K |
PCR_FFHI_8K | PCR_STLO_4 | PCR_STHI_8 | PCR_PAUSE_CNT),
dev->base + PCR);
/* Disable Wake On Lan */
writel(0, dev->base + WCSR);
ns83820_getmac(dev, ndev->dev_addr);
/* Yes, we support dumb IP checksum on transmit */
ndev->features |= NETIF_F_SG;
ndev->features |= NETIF_F_IP_CSUM;
#ifdef NS83820_VLAN_ACCEL_SUPPORT
/* We also support hardware vlan acceleration */
ndev->features |= NETIF_F_HW_VLAN_TX | NETIF_F_HW_VLAN_RX;
ndev->vlan_rx_register = ns83820_vlan_rx_register;
#endif
if (using_dac) {
printk(KERN_INFO "%s: using 64 bit addressing.\n",
ndev->name);
ndev->features |= NETIF_F_HIGHDMA;
}
printk(KERN_INFO "%s: ns83820 v" VERSION ": DP83820 v%u.%u: %s io=0x%08lx irq=%d f=%s\n",
ndev->name,
(unsigned)readl(dev->base + SRR) >> 8,
(unsigned)readl(dev->base + SRR) & 0xff,
print_mac(mac, ndev->dev_addr),
addr, pci_dev->irq,
(ndev->features & NETIF_F_HIGHDMA) ? "h,sg" : "sg"
);
#ifdef PHY_CODE_IS_FINISHED
ns83820_probe_phy(ndev);
#endif
err = register_netdevice(ndev);
if (err) {
printk(KERN_INFO "ns83820: unable to register netdev: %d\n", err);
goto out_cleanup;
}
rtnl_unlock();
return 0;
out_cleanup:
writel(0, dev->base + IMR); /* paranoia */
writel(0, dev->base + IER);
readl(dev->base + IER);
out_free_irq:
rtnl_unlock();
free_irq(pci_dev->irq, ndev);
out_disable:
if (dev->base)
iounmap(dev->base);
pci_free_consistent(pci_dev, 4 * DESC_SIZE * NR_TX_DESC, dev->tx_descs, dev->tx_phy_descs);
pci_free_consistent(pci_dev, 4 * DESC_SIZE * NR_RX_DESC, dev->rx_info.descs, dev->rx_info.phy_descs);
pci_disable_device(pci_dev);
out_free:
free_netdev(ndev);
pci_set_drvdata(pci_dev, NULL);
out:
return err;
}
static void __devexit ns83820_remove_one(struct pci_dev *pci_dev)
{
struct net_device *ndev = pci_get_drvdata(pci_dev);
struct ns83820 *dev = PRIV(ndev); /* ok even if NULL */
if (!ndev) /* paranoia */
return;
writel(0, dev->base + IMR); /* paranoia */
writel(0, dev->base + IER);
readl(dev->base + IER);
unregister_netdev(ndev);
free_irq(dev->pci_dev->irq, ndev);
iounmap(dev->base);
pci_free_consistent(dev->pci_dev, 4 * DESC_SIZE * NR_TX_DESC,
dev->tx_descs, dev->tx_phy_descs);
pci_free_consistent(dev->pci_dev, 4 * DESC_SIZE * NR_RX_DESC,
dev->rx_info.descs, dev->rx_info.phy_descs);
pci_disable_device(dev->pci_dev);
free_netdev(ndev);
pci_set_drvdata(pci_dev, NULL);
}
static struct pci_device_id ns83820_pci_tbl[] = {
{ 0x100b, 0x0022, PCI_ANY_ID, PCI_ANY_ID, 0, .driver_data = 0, },
{ 0, },
};
static struct pci_driver driver = {
.name = "ns83820",
.id_table = ns83820_pci_tbl,
.probe = ns83820_init_one,
.remove = __devexit_p(ns83820_remove_one),
#if 0 /* FIXME: implement */
.suspend = ,
.resume = ,
#endif
};
static int __init ns83820_init(void)
{
printk(KERN_INFO "ns83820.c: National Semiconductor DP83820 10/100/1000 driver.\n");
return pci_register_driver(&driver);
}
static void __exit ns83820_exit(void)
{
pci_unregister_driver(&driver);
}
MODULE_AUTHOR("Benjamin LaHaise <bcrl@kvack.org>");
MODULE_DESCRIPTION("National Semiconductor DP83820 10/100/1000 driver");
MODULE_LICENSE("GPL");
MODULE_DEVICE_TABLE(pci, ns83820_pci_tbl);
module_param(lnksts, int, 0);
MODULE_PARM_DESC(lnksts, "Polarity of LNKSTS bit");
module_param(ihr, int, 0);
MODULE_PARM_DESC(ihr, "Time in 100 us increments to delay interrupts (range 0-127)");
module_param(reset_phy, int, 0);
MODULE_PARM_DESC(reset_phy, "Set to 1 to reset the PHY on startup");
module_init(ns83820_init);
module_exit(ns83820_exit);