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linux/drivers/serial/jsm/jsm.h
David Howells 7d12e780e0 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 15:10:12 +01:00

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/************************************************************************
* Copyright 2003 Digi International (www.digi.com)
*
* Copyright (C) 2004 IBM Corporation. All rights reserved.
*
* 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, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY, EXPRESS OR IMPLIED; 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.
*
* Contact Information:
* Scott H Kilau <Scott_Kilau@digi.com>
* Wendy Xiong <wendyx@us.ibm.com>
*
***********************************************************************/
#ifndef __JSM_DRIVER_H
#define __JSM_DRIVER_H
#include <linux/kernel.h>
#include <linux/types.h> /* To pick up the varions Linux types */
#include <linux/tty.h>
#include <linux/serial_core.h>
#include <linux/device.h>
/*
* Debugging levels can be set using debug insmod variable
* They can also be compiled out completely.
*/
enum {
DBG_INIT = 0x01,
DBG_BASIC = 0x02,
DBG_CORE = 0x04,
DBG_OPEN = 0x08,
DBG_CLOSE = 0x10,
DBG_READ = 0x20,
DBG_WRITE = 0x40,
DBG_IOCTL = 0x80,
DBG_PROC = 0x100,
DBG_PARAM = 0x200,
DBG_PSCAN = 0x400,
DBG_EVENT = 0x800,
DBG_DRAIN = 0x1000,
DBG_MSIGS = 0x2000,
DBG_MGMT = 0x4000,
DBG_INTR = 0x8000,
DBG_CARR = 0x10000,
};
#define jsm_printk(nlevel, klevel, pdev, fmt, args...) \
if ((DBG_##nlevel & jsm_debug)) \
dev_printk(KERN_##klevel, pdev->dev, fmt, ## args)
#define MAXPORTS 8
#define MAX_STOPS_SENT 5
/* Board type definitions */
#define T_NEO 0000
#define T_CLASSIC 0001
#define T_PCIBUS 0400
/* Board State Definitions */
#define BD_RUNNING 0x0
#define BD_REASON 0x7f
#define BD_NOTFOUND 0x1
#define BD_NOIOPORT 0x2
#define BD_NOMEM 0x3
#define BD_NOBIOS 0x4
#define BD_NOFEP 0x5
#define BD_FAILED 0x6
#define BD_ALLOCATED 0x7
#define BD_TRIBOOT 0x8
#define BD_BADKME 0x80
/* 4 extra for alignment play space */
#define WRITEBUFLEN ((4096) + 4)
#define MYFLIPLEN N_TTY_BUF_SIZE
#define JSM_VERSION "jsm: 1.2-1-INKERNEL"
#define JSM_PARTNUM "40002438_A-INKERNEL"
struct jsm_board;
struct jsm_channel;
/************************************************************************
* Per board operations structure *
************************************************************************/
struct board_ops {
irq_handler_t intr;
void (*uart_init) (struct jsm_channel *ch);
void (*uart_off) (struct jsm_channel *ch);
void (*param) (struct jsm_channel *ch);
void (*assert_modem_signals) (struct jsm_channel *ch);
void (*flush_uart_write) (struct jsm_channel *ch);
void (*flush_uart_read) (struct jsm_channel *ch);
void (*disable_receiver) (struct jsm_channel *ch);
void (*enable_receiver) (struct jsm_channel *ch);
void (*send_break) (struct jsm_channel *ch);
void (*clear_break) (struct jsm_channel *ch, int);
void (*send_start_character) (struct jsm_channel *ch);
void (*send_stop_character) (struct jsm_channel *ch);
void (*copy_data_from_queue_to_uart) (struct jsm_channel *ch);
u32 (*get_uart_bytes_left) (struct jsm_channel *ch);
void (*send_immediate_char) (struct jsm_channel *ch, unsigned char);
};
/*
* Per-board information
*/
struct jsm_board
{
int boardnum; /* Board number: 0-32 */
int type; /* Type of board */
u8 rev; /* PCI revision ID */
struct pci_dev *pci_dev;
u32 maxports; /* MAX ports this board can handle */
spinlock_t bd_lock; /* Used to protect board */
spinlock_t bd_intr_lock; /* Used to protect the poller tasklet and
* the interrupt routine from each other.
*/
u32 nasync; /* Number of ports on card */
u32 irq; /* Interrupt request number */
u64 intr_count; /* Count of interrupts */
u64 membase; /* Start of base memory of the card */
u64 membase_end; /* End of base memory of the card */
u8 __iomem *re_map_membase;/* Remapped memory of the card */
u64 iobase; /* Start of io base of the card */
u64 iobase_end; /* End of io base of the card */
u32 bd_uart_offset; /* Space between each UART */
struct jsm_channel *channels[MAXPORTS]; /* array of pointers to our channels. */
char *flipbuf; /* Our flip buffer, alloced if board is found */
u32 bd_dividend; /* Board/UARTs specific dividend */
struct board_ops *bd_ops;
struct list_head jsm_board_entry;
};
/************************************************************************
* Device flag definitions for ch_flags.
************************************************************************/
#define CH_PRON 0x0001 /* Printer on string */
#define CH_STOP 0x0002 /* Output is stopped */
#define CH_STOPI 0x0004 /* Input is stopped */
#define CH_CD 0x0008 /* Carrier is present */
#define CH_FCAR 0x0010 /* Carrier forced on */
#define CH_HANGUP 0x0020 /* Hangup received */
#define CH_RECEIVER_OFF 0x0040 /* Receiver is off */
#define CH_OPENING 0x0080 /* Port in fragile open state */
#define CH_CLOSING 0x0100 /* Port in fragile close state */
#define CH_FIFO_ENABLED 0x0200 /* Port has FIFOs enabled */
#define CH_TX_FIFO_EMPTY 0x0400 /* TX Fifo is completely empty */
#define CH_TX_FIFO_LWM 0x0800 /* TX Fifo is below Low Water */
#define CH_BREAK_SENDING 0x1000 /* Break is being sent */
#define CH_LOOPBACK 0x2000 /* Channel is in lookback mode */
#define CH_FLIPBUF_IN_USE 0x4000 /* Channel's flipbuf is in use */
#define CH_BAUD0 0x08000 /* Used for checking B0 transitions */
/* Our Read/Error/Write queue sizes */
#define RQUEUEMASK 0x1FFF /* 8 K - 1 */
#define EQUEUEMASK 0x1FFF /* 8 K - 1 */
#define WQUEUEMASK 0x0FFF /* 4 K - 1 */
#define RQUEUESIZE (RQUEUEMASK + 1)
#define EQUEUESIZE RQUEUESIZE
#define WQUEUESIZE (WQUEUEMASK + 1)
/************************************************************************
* Channel information structure.
************************************************************************/
struct jsm_channel {
struct uart_port uart_port;
struct jsm_board *ch_bd; /* Board structure pointer */
spinlock_t ch_lock; /* provide for serialization */
wait_queue_head_t ch_flags_wait;
u32 ch_portnum; /* Port number, 0 offset. */
u32 ch_open_count; /* open count */
u32 ch_flags; /* Channel flags */
u64 ch_close_delay; /* How long we should drop RTS/DTR for */
u64 ch_cpstime; /* Time for CPS calculations */
tcflag_t ch_c_iflag; /* channel iflags */
tcflag_t ch_c_cflag; /* channel cflags */
tcflag_t ch_c_oflag; /* channel oflags */
tcflag_t ch_c_lflag; /* channel lflags */
u8 ch_stopc; /* Stop character */
u8 ch_startc; /* Start character */
u32 ch_old_baud; /* Cache of the current baud */
u32 ch_custom_speed;/* Custom baud, if set */
u32 ch_wopen; /* Waiting for open process cnt */
u8 ch_mostat; /* FEP output modem status */
u8 ch_mistat; /* FEP input modem status */
struct neo_uart_struct __iomem *ch_neo_uart; /* Pointer to the "mapped" UART struct */
u8 ch_cached_lsr; /* Cached value of the LSR register */
u8 *ch_rqueue; /* Our read queue buffer - malloc'ed */
u16 ch_r_head; /* Head location of the read queue */
u16 ch_r_tail; /* Tail location of the read queue */
u8 *ch_equeue; /* Our error queue buffer - malloc'ed */
u16 ch_e_head; /* Head location of the error queue */
u16 ch_e_tail; /* Tail location of the error queue */
u8 *ch_wqueue; /* Our write queue buffer - malloc'ed */
u16 ch_w_head; /* Head location of the write queue */
u16 ch_w_tail; /* Tail location of the write queue */
u64 ch_rxcount; /* total of data received so far */
u64 ch_txcount; /* total of data transmitted so far */
u8 ch_r_tlevel; /* Receive Trigger level */
u8 ch_t_tlevel; /* Transmit Trigger level */
u8 ch_r_watermark; /* Receive Watermark */
u32 ch_stops_sent; /* How many times I have sent a stop character
* to try to stop the other guy sending.
*/
u64 ch_err_parity; /* Count of parity errors on channel */
u64 ch_err_frame; /* Count of framing errors on channel */
u64 ch_err_break; /* Count of breaks on channel */
u64 ch_err_overrun; /* Count of overruns on channel */
u64 ch_xon_sends; /* Count of xons transmitted */
u64 ch_xoff_sends; /* Count of xoffs transmitted */
};
/************************************************************************
* Per channel/port NEO UART structure *
************************************************************************
* Base Structure Entries Usage Meanings to Host *
* *
* W = read write R = read only *
* U = Unused. *
************************************************************************/
struct neo_uart_struct {
u8 txrx; /* WR RHR/THR - Holding Reg */
u8 ier; /* WR IER - Interrupt Enable Reg */
u8 isr_fcr; /* WR ISR/FCR - Interrupt Status Reg/Fifo Control Reg */
u8 lcr; /* WR LCR - Line Control Reg */
u8 mcr; /* WR MCR - Modem Control Reg */
u8 lsr; /* WR LSR - Line Status Reg */
u8 msr; /* WR MSR - Modem Status Reg */
u8 spr; /* WR SPR - Scratch Pad Reg */
u8 fctr; /* WR FCTR - Feature Control Reg */
u8 efr; /* WR EFR - Enhanced Function Reg */
u8 tfifo; /* WR TXCNT/TXTRG - Transmit FIFO Reg */
u8 rfifo; /* WR RXCNT/RXTRG - Recieve FIFO Reg */
u8 xoffchar1; /* WR XOFF 1 - XOff Character 1 Reg */
u8 xoffchar2; /* WR XOFF 2 - XOff Character 2 Reg */
u8 xonchar1; /* WR XON 1 - Xon Character 1 Reg */
u8 xonchar2; /* WR XON 2 - XOn Character 2 Reg */
u8 reserved1[0x2ff - 0x200]; /* U Reserved by Exar */
u8 txrxburst[64]; /* RW 64 bytes of RX/TX FIFO Data */
u8 reserved2[0x37f - 0x340]; /* U Reserved by Exar */
u8 rxburst_with_errors[64]; /* R 64 bytes of RX FIFO Data + LSR */
};
/* Where to read the extended interrupt register (32bits instead of 8bits) */
#define UART_17158_POLL_ADDR_OFFSET 0x80
/*
* These are the redefinitions for the FCTR on the XR17C158, since
* Exar made them different than their earlier design. (XR16C854)
*/
/* These are only applicable when table D is selected */
#define UART_17158_FCTR_RTS_NODELAY 0x00
#define UART_17158_FCTR_RTS_4DELAY 0x01
#define UART_17158_FCTR_RTS_6DELAY 0x02
#define UART_17158_FCTR_RTS_8DELAY 0x03
#define UART_17158_FCTR_RTS_12DELAY 0x12
#define UART_17158_FCTR_RTS_16DELAY 0x05
#define UART_17158_FCTR_RTS_20DELAY 0x13
#define UART_17158_FCTR_RTS_24DELAY 0x06
#define UART_17158_FCTR_RTS_28DELAY 0x14
#define UART_17158_FCTR_RTS_32DELAY 0x07
#define UART_17158_FCTR_RTS_36DELAY 0x16
#define UART_17158_FCTR_RTS_40DELAY 0x08
#define UART_17158_FCTR_RTS_44DELAY 0x09
#define UART_17158_FCTR_RTS_48DELAY 0x10
#define UART_17158_FCTR_RTS_52DELAY 0x11
#define UART_17158_FCTR_RTS_IRDA 0x10
#define UART_17158_FCTR_RS485 0x20
#define UART_17158_FCTR_TRGA 0x00
#define UART_17158_FCTR_TRGB 0x40
#define UART_17158_FCTR_TRGC 0x80
#define UART_17158_FCTR_TRGD 0xC0
/* 17158 trigger table selects.. */
#define UART_17158_FCTR_BIT6 0x40
#define UART_17158_FCTR_BIT7 0x80
/* 17158 TX/RX memmapped buffer offsets */
#define UART_17158_RX_FIFOSIZE 64
#define UART_17158_TX_FIFOSIZE 64
/* 17158 Extended IIR's */
#define UART_17158_IIR_RDI_TIMEOUT 0x0C /* Receiver data TIMEOUT */
#define UART_17158_IIR_XONXOFF 0x10 /* Received an XON/XOFF char */
#define UART_17158_IIR_HWFLOW_STATE_CHANGE 0x20 /* CTS/DSR or RTS/DTR state change */
#define UART_17158_IIR_FIFO_ENABLED 0xC0 /* 16550 FIFOs are Enabled */
/*
* These are the extended interrupts that get sent
* back to us from the UART's 32bit interrupt register
*/
#define UART_17158_RX_LINE_STATUS 0x1 /* RX Ready */
#define UART_17158_RXRDY_TIMEOUT 0x2 /* RX Ready Timeout */
#define UART_17158_TXRDY 0x3 /* TX Ready */
#define UART_17158_MSR 0x4 /* Modem State Change */
#define UART_17158_TX_AND_FIFO_CLR 0x40 /* Transmitter Holding Reg Empty */
#define UART_17158_RX_FIFO_DATA_ERROR 0x80 /* UART detected an RX FIFO Data error */
/*
* These are the EXTENDED definitions for the 17C158's Interrupt
* Enable Register.
*/
#define UART_17158_EFR_ECB 0x10 /* Enhanced control bit */
#define UART_17158_EFR_IXON 0x2 /* Receiver compares Xon1/Xoff1 */
#define UART_17158_EFR_IXOFF 0x8 /* Transmit Xon1/Xoff1 */
#define UART_17158_EFR_RTSDTR 0x40 /* Auto RTS/DTR Flow Control Enable */
#define UART_17158_EFR_CTSDSR 0x80 /* Auto CTS/DSR Flow COntrol Enable */
#define UART_17158_XOFF_DETECT 0x1 /* Indicates whether chip saw an incoming XOFF char */
#define UART_17158_XON_DETECT 0x2 /* Indicates whether chip saw an incoming XON char */
#define UART_17158_IER_RSVD1 0x10 /* Reserved by Exar */
#define UART_17158_IER_XOFF 0x20 /* Xoff Interrupt Enable */
#define UART_17158_IER_RTSDTR 0x40 /* Output Interrupt Enable */
#define UART_17158_IER_CTSDSR 0x80 /* Input Interrupt Enable */
#define PCI_DEVICE_NEO_2DB9_PCI_NAME "Neo 2 - DB9 Universal PCI"
#define PCI_DEVICE_NEO_2DB9PRI_PCI_NAME "Neo 2 - DB9 Universal PCI - Powered Ring Indicator"
#define PCI_DEVICE_NEO_2RJ45_PCI_NAME "Neo 2 - RJ45 Universal PCI"
#define PCI_DEVICE_NEO_2RJ45PRI_PCI_NAME "Neo 2 - RJ45 Universal PCI - Powered Ring Indicator"
/*
* Our Global Variables.
*/
extern struct uart_driver jsm_uart_driver;
extern struct board_ops jsm_neo_ops;
extern int jsm_debug;
/*************************************************************************
*
* Prototypes for non-static functions used in more than one module
*
*************************************************************************/
int jsm_tty_write(struct uart_port *port);
int jsm_tty_init(struct jsm_board *);
int jsm_uart_port_init(struct jsm_board *);
int jsm_remove_uart_port(struct jsm_board *);
void jsm_input(struct jsm_channel *ch);
void jsm_check_queue_flow_control(struct jsm_channel *ch);
#endif
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