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linux/drivers/scsi/arm/eesox.c
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

679 lines
17 KiB
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/*
* linux/drivers/acorn/scsi/eesox.c
*
* Copyright (C) 1997-2005 Russell King
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License version 2 as
* published by the Free Software Foundation.
*
* This driver is based on experimentation. Hence, it may have made
* assumptions about the particular card that I have available, and
* may not be reliable!
*
* Changelog:
* 01-10-1997 RMK Created, READONLY version
* 15-02-1998 RMK READ/WRITE version
* added DMA support and hardware definitions
* 14-03-1998 RMK Updated DMA support
* Added terminator control
* 15-04-1998 RMK Only do PIO if FAS216 will allow it.
* 27-06-1998 RMK Changed asm/delay.h to linux/delay.h
* 02-04-2000 RMK 0.0.3 Fixed NO_IRQ/NO_DMA problem, updated for new
* error handling code.
*/
#include <linux/module.h>
#include <linux/blkdev.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/ioport.h>
#include <linux/sched.h>
#include <linux/proc_fs.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/dma-mapping.h>
#include <asm/io.h>
#include <asm/dma.h>
#include <asm/ecard.h>
#include <asm/pgtable.h>
#include "../scsi.h"
#include <scsi/scsi_host.h>
#include "fas216.h"
#include "scsi.h"
#include <scsi/scsicam.h>
#define EESOX_FAS216_OFFSET 0x3000
#define EESOX_FAS216_SHIFT 5
#define EESOX_DMASTAT 0x2800
#define EESOX_STAT_INTR 0x01
#define EESOX_STAT_DMA 0x02
#define EESOX_CONTROL 0x2800
#define EESOX_INTR_ENABLE 0x04
#define EESOX_TERM_ENABLE 0x02
#define EESOX_RESET 0x01
#define EESOX_DMADATA 0x3800
#define VERSION "1.10 (17/01/2003 2.5.59)"
/*
* Use term=0,1,0,0,0 to turn terminators on/off
*/
static int term[MAX_ECARDS] = { 1, 1, 1, 1, 1, 1, 1, 1 };
#define NR_SG 256
struct eesoxscsi_info {
FAS216_Info info;
struct expansion_card *ec;
void __iomem *base;
void __iomem *ctl_port;
unsigned int control;
struct scatterlist sg[NR_SG]; /* Scatter DMA list */
};
/* Prototype: void eesoxscsi_irqenable(ec, irqnr)
* Purpose : Enable interrupts on EESOX SCSI card
* Params : ec - expansion card structure
* : irqnr - interrupt number
*/
static void
eesoxscsi_irqenable(struct expansion_card *ec, int irqnr)
{
struct eesoxscsi_info *info = (struct eesoxscsi_info *)ec->irq_data;
info->control |= EESOX_INTR_ENABLE;
writeb(info->control, info->ctl_port);
}
/* Prototype: void eesoxscsi_irqdisable(ec, irqnr)
* Purpose : Disable interrupts on EESOX SCSI card
* Params : ec - expansion card structure
* : irqnr - interrupt number
*/
static void
eesoxscsi_irqdisable(struct expansion_card *ec, int irqnr)
{
struct eesoxscsi_info *info = (struct eesoxscsi_info *)ec->irq_data;
info->control &= ~EESOX_INTR_ENABLE;
writeb(info->control, info->ctl_port);
}
static const expansioncard_ops_t eesoxscsi_ops = {
.irqenable = eesoxscsi_irqenable,
.irqdisable = eesoxscsi_irqdisable,
};
/* Prototype: void eesoxscsi_terminator_ctl(*host, on_off)
* Purpose : Turn the EESOX SCSI terminators on or off
* Params : host - card to turn on/off
* : on_off - !0 to turn on, 0 to turn off
*/
static void
eesoxscsi_terminator_ctl(struct Scsi_Host *host, int on_off)
{
struct eesoxscsi_info *info = (struct eesoxscsi_info *)host->hostdata;
unsigned long flags;
spin_lock_irqsave(host->host_lock, flags);
if (on_off)
info->control |= EESOX_TERM_ENABLE;
else
info->control &= ~EESOX_TERM_ENABLE;
writeb(info->control, info->ctl_port);
spin_unlock_irqrestore(host->host_lock, flags);
}
/* Prototype: void eesoxscsi_intr(irq, *dev_id, *regs)
* Purpose : handle interrupts from EESOX SCSI card
* Params : irq - interrupt number
* dev_id - user-defined (Scsi_Host structure)
*/
static irqreturn_t
eesoxscsi_intr(int irq, void *dev_id)
{
struct eesoxscsi_info *info = dev_id;
return fas216_intr(&info->info);
}
/* Prototype: fasdmatype_t eesoxscsi_dma_setup(host, SCpnt, direction, min_type)
* Purpose : initialises DMA/PIO
* Params : host - host
* SCpnt - command
* direction - DMA on to/off of card
* min_type - minimum DMA support that we must have for this transfer
* Returns : type of transfer to be performed
*/
static fasdmatype_t
eesoxscsi_dma_setup(struct Scsi_Host *host, struct scsi_pointer *SCp,
fasdmadir_t direction, fasdmatype_t min_type)
{
struct eesoxscsi_info *info = (struct eesoxscsi_info *)host->hostdata;
struct device *dev = scsi_get_device(host);
int dmach = info->info.scsi.dma;
if (dmach != NO_DMA &&
(min_type == fasdma_real_all || SCp->this_residual >= 512)) {
int bufs, map_dir, dma_dir;
bufs = copy_SCp_to_sg(&info->sg[0], SCp, NR_SG);
if (direction == DMA_OUT)
map_dir = DMA_TO_DEVICE,
dma_dir = DMA_MODE_WRITE;
else
map_dir = DMA_FROM_DEVICE,
dma_dir = DMA_MODE_READ;
dma_map_sg(dev, info->sg, bufs + 1, map_dir);
disable_dma(dmach);
set_dma_sg(dmach, info->sg, bufs + 1);
set_dma_mode(dmach, dma_dir);
enable_dma(dmach);
return fasdma_real_all;
}
/*
* We don't do DMA, we only do slow PIO
*
* Some day, we will do Pseudo DMA
*/
return fasdma_pseudo;
}
static void eesoxscsi_buffer_in(void *buf, int length, void __iomem *base)
{
const void __iomem *reg_fas = base + EESOX_FAS216_OFFSET;
const void __iomem *reg_dmastat = base + EESOX_DMASTAT;
const void __iomem *reg_dmadata = base + EESOX_DMADATA;
const register unsigned long mask = 0xffff;
do {
unsigned int status;
/*
* Interrupt request?
*/
status = readb(reg_fas + (REG_STAT << EESOX_FAS216_SHIFT));
if (status & STAT_INT)
break;
/*
* DMA request active?
*/
status = readb(reg_dmastat);
if (!(status & EESOX_STAT_DMA))
continue;
/*
* Get number of bytes in FIFO
*/
status = readb(reg_fas + (REG_CFIS << EESOX_FAS216_SHIFT)) & CFIS_CF;
if (status > 16)
status = 16;
if (status > length)
status = length;
/*
* Align buffer.
*/
if (((u32)buf) & 2 && status >= 2) {
*(u16 *)buf = readl(reg_dmadata);
buf += 2;
status -= 2;
length -= 2;
}
if (status >= 8) {
unsigned long l1, l2;
l1 = readl(reg_dmadata) & mask;
l1 |= readl(reg_dmadata) << 16;
l2 = readl(reg_dmadata) & mask;
l2 |= readl(reg_dmadata) << 16;
*(u32 *)buf = l1;
buf += 4;
*(u32 *)buf = l2;
buf += 4;
length -= 8;
continue;
}
if (status >= 4) {
unsigned long l1;
l1 = readl(reg_dmadata) & mask;
l1 |= readl(reg_dmadata) << 16;
*(u32 *)buf = l1;
buf += 4;
length -= 4;
continue;
}
if (status >= 2) {
*(u16 *)buf = readl(reg_dmadata);
buf += 2;
length -= 2;
}
} while (length);
}
static void eesoxscsi_buffer_out(void *buf, int length, void __iomem *base)
{
const void __iomem *reg_fas = base + EESOX_FAS216_OFFSET;
const void __iomem *reg_dmastat = base + EESOX_DMASTAT;
const void __iomem *reg_dmadata = base + EESOX_DMADATA;
do {
unsigned int status;
/*
* Interrupt request?
*/
status = readb(reg_fas + (REG_STAT << EESOX_FAS216_SHIFT));
if (status & STAT_INT)
break;
/*
* DMA request active?
*/
status = readb(reg_dmastat);
if (!(status & EESOX_STAT_DMA))
continue;
/*
* Get number of bytes in FIFO
*/
status = readb(reg_fas + (REG_CFIS << EESOX_FAS216_SHIFT)) & CFIS_CF;
if (status > 16)
status = 16;
status = 16 - status;
if (status > length)
status = length;
status &= ~1;
/*
* Align buffer.
*/
if (((u32)buf) & 2 && status >= 2) {
writel(*(u16 *)buf << 16, reg_dmadata);
buf += 2;
status -= 2;
length -= 2;
}
if (status >= 8) {
unsigned long l1, l2;
l1 = *(u32 *)buf;
buf += 4;
l2 = *(u32 *)buf;
buf += 4;
writel(l1 << 16, reg_dmadata);
writel(l1, reg_dmadata);
writel(l2 << 16, reg_dmadata);
writel(l2, reg_dmadata);
length -= 8;
continue;
}
if (status >= 4) {
unsigned long l1;
l1 = *(u32 *)buf;
buf += 4;
writel(l1 << 16, reg_dmadata);
writel(l1, reg_dmadata);
length -= 4;
continue;
}
if (status >= 2) {
writel(*(u16 *)buf << 16, reg_dmadata);
buf += 2;
length -= 2;
}
} while (length);
}
static void
eesoxscsi_dma_pseudo(struct Scsi_Host *host, struct scsi_pointer *SCp,
fasdmadir_t dir, int transfer_size)
{
struct eesoxscsi_info *info = (struct eesoxscsi_info *)host->hostdata;
if (dir == DMA_IN) {
eesoxscsi_buffer_in(SCp->ptr, SCp->this_residual, info->base);
} else {
eesoxscsi_buffer_out(SCp->ptr, SCp->this_residual, info->base);
}
}
/* Prototype: int eesoxscsi_dma_stop(host, SCpnt)
* Purpose : stops DMA/PIO
* Params : host - host
* SCpnt - command
*/
static void
eesoxscsi_dma_stop(struct Scsi_Host *host, struct scsi_pointer *SCp)
{
struct eesoxscsi_info *info = (struct eesoxscsi_info *)host->hostdata;
if (info->info.scsi.dma != NO_DMA)
disable_dma(info->info.scsi.dma);
}
/* Prototype: const char *eesoxscsi_info(struct Scsi_Host * host)
* Purpose : returns a descriptive string about this interface,
* Params : host - driver host structure to return info for.
* Returns : pointer to a static buffer containing null terminated string.
*/
const char *eesoxscsi_info(struct Scsi_Host *host)
{
struct eesoxscsi_info *info = (struct eesoxscsi_info *)host->hostdata;
static char string[150];
sprintf(string, "%s (%s) in slot %d v%s terminators o%s",
host->hostt->name, info->info.scsi.type, info->ec->slot_no,
VERSION, info->control & EESOX_TERM_ENABLE ? "n" : "ff");
return string;
}
/* Prototype: int eesoxscsi_set_proc_info(struct Scsi_Host *host, char *buffer, int length)
* Purpose : Set a driver specific function
* Params : host - host to setup
* : buffer - buffer containing string describing operation
* : length - length of string
* Returns : -EINVAL, or 0
*/
static int
eesoxscsi_set_proc_info(struct Scsi_Host *host, char *buffer, int length)
{
int ret = length;
if (length >= 9 && strncmp(buffer, "EESOXSCSI", 9) == 0) {
buffer += 9;
length -= 9;
if (length >= 5 && strncmp(buffer, "term=", 5) == 0) {
if (buffer[5] == '1')
eesoxscsi_terminator_ctl(host, 1);
else if (buffer[5] == '0')
eesoxscsi_terminator_ctl(host, 0);
else
ret = -EINVAL;
} else
ret = -EINVAL;
} else
ret = -EINVAL;
return ret;
}
/* Prototype: int eesoxscsi_proc_info(char *buffer, char **start, off_t offset,
* int length, int host_no, int inout)
* Purpose : Return information about the driver to a user process accessing
* the /proc filesystem.
* Params : buffer - a buffer to write information to
* start - a pointer into this buffer set by this routine to the start
* of the required information.
* offset - offset into information that we have read upto.
* length - length of buffer
* host_no - host number to return information for
* inout - 0 for reading, 1 for writing.
* Returns : length of data written to buffer.
*/
int eesoxscsi_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset,
int length, int inout)
{
struct eesoxscsi_info *info;
char *p = buffer;
int pos;
if (inout == 1)
return eesoxscsi_set_proc_info(host, buffer, length);
info = (struct eesoxscsi_info *)host->hostdata;
p += sprintf(p, "EESOX SCSI driver v%s\n", VERSION);
p += fas216_print_host(&info->info, p);
p += sprintf(p, "Term : o%s\n",
info->control & EESOX_TERM_ENABLE ? "n" : "ff");
p += fas216_print_stats(&info->info, p);
p += fas216_print_devices(&info->info, p);
*start = buffer + offset;
pos = p - buffer - offset;
if (pos > length)
pos = length;
return pos;
}
static ssize_t eesoxscsi_show_term(struct device *dev, struct device_attribute *attr, char *buf)
{
struct expansion_card *ec = ECARD_DEV(dev);
struct Scsi_Host *host = ecard_get_drvdata(ec);
struct eesoxscsi_info *info = (struct eesoxscsi_info *)host->hostdata;
return sprintf(buf, "%d\n", info->control & EESOX_TERM_ENABLE ? 1 : 0);
}
static ssize_t eesoxscsi_store_term(struct device *dev, struct device_attribute *attr, const char *buf, size_t len)
{
struct expansion_card *ec = ECARD_DEV(dev);
struct Scsi_Host *host = ecard_get_drvdata(ec);
struct eesoxscsi_info *info = (struct eesoxscsi_info *)host->hostdata;
unsigned long flags;
if (len > 1) {
spin_lock_irqsave(host->host_lock, flags);
if (buf[0] != '0') {
info->control |= EESOX_TERM_ENABLE;
} else {
info->control &= ~EESOX_TERM_ENABLE;
}
writeb(info->control, info->ctl_port);
spin_unlock_irqrestore(host->host_lock, flags);
}
return len;
}
static DEVICE_ATTR(bus_term, S_IRUGO | S_IWUSR,
eesoxscsi_show_term, eesoxscsi_store_term);
static struct scsi_host_template eesox_template = {
.module = THIS_MODULE,
.proc_info = eesoxscsi_proc_info,
.name = "EESOX SCSI",
.info = eesoxscsi_info,
.queuecommand = fas216_queue_command,
.eh_host_reset_handler = fas216_eh_host_reset,
.eh_bus_reset_handler = fas216_eh_bus_reset,
.eh_device_reset_handler = fas216_eh_device_reset,
.eh_abort_handler = fas216_eh_abort,
.can_queue = 1,
.this_id = 7,
.sg_tablesize = SG_ALL,
.cmd_per_lun = 1,
.use_clustering = DISABLE_CLUSTERING,
.proc_name = "eesox",
};
static int __devinit
eesoxscsi_probe(struct expansion_card *ec, const struct ecard_id *id)
{
struct Scsi_Host *host;
struct eesoxscsi_info *info;
unsigned long resbase, reslen;
void __iomem *base;
int ret;
ret = ecard_request_resources(ec);
if (ret)
goto out;
resbase = ecard_resource_start(ec, ECARD_RES_IOCFAST);
reslen = ecard_resource_len(ec, ECARD_RES_IOCFAST);
base = ioremap(resbase, reslen);
if (!base) {
ret = -ENOMEM;
goto out_region;
}
host = scsi_host_alloc(&eesox_template,
sizeof(struct eesoxscsi_info));
if (!host) {
ret = -ENOMEM;
goto out_unmap;
}
ecard_set_drvdata(ec, host);
info = (struct eesoxscsi_info *)host->hostdata;
info->ec = ec;
info->base = base;
info->ctl_port = base + EESOX_CONTROL;
info->control = term[ec->slot_no] ? EESOX_TERM_ENABLE : 0;
writeb(info->control, info->ctl_port);
info->info.scsi.io_base = base + EESOX_FAS216_OFFSET;
info->info.scsi.io_shift = EESOX_FAS216_SHIFT;
info->info.scsi.irq = ec->irq;
info->info.scsi.dma = ec->dma;
info->info.ifcfg.clockrate = 40; /* MHz */
info->info.ifcfg.select_timeout = 255;
info->info.ifcfg.asyncperiod = 200; /* ns */
info->info.ifcfg.sync_max_depth = 7;
info->info.ifcfg.cntl3 = CNTL3_FASTSCSI | CNTL3_FASTCLK;
info->info.ifcfg.disconnect_ok = 1;
info->info.ifcfg.wide_max_size = 0;
info->info.ifcfg.capabilities = FASCAP_PSEUDODMA;
info->info.dma.setup = eesoxscsi_dma_setup;
info->info.dma.pseudo = eesoxscsi_dma_pseudo;
info->info.dma.stop = eesoxscsi_dma_stop;
ec->irqaddr = base + EESOX_DMASTAT;
ec->irqmask = EESOX_STAT_INTR;
ec->irq_data = info;
ec->ops = &eesoxscsi_ops;
device_create_file(&ec->dev, &dev_attr_bus_term);
ret = fas216_init(host);
if (ret)
goto out_free;
ret = request_irq(ec->irq, eesoxscsi_intr, 0, "eesoxscsi", info);
if (ret) {
printk("scsi%d: IRQ%d not free: %d\n",
host->host_no, ec->irq, ret);
goto out_remove;
}
if (info->info.scsi.dma != NO_DMA) {
if (request_dma(info->info.scsi.dma, "eesox")) {
printk("scsi%d: DMA%d not free, DMA disabled\n",
host->host_no, info->info.scsi.dma);
info->info.scsi.dma = NO_DMA;
} else {
set_dma_speed(info->info.scsi.dma, 180);
info->info.ifcfg.capabilities |= FASCAP_DMA;
info->info.ifcfg.cntl3 |= CNTL3_BS8;
}
}
ret = fas216_add(host, &ec->dev);
if (ret == 0)
goto out;
if (info->info.scsi.dma != NO_DMA)
free_dma(info->info.scsi.dma);
free_irq(ec->irq, host);
out_remove:
fas216_remove(host);
out_free:
device_remove_file(&ec->dev, &dev_attr_bus_term);
scsi_host_put(host);
out_unmap:
iounmap(base);
out_region:
ecard_release_resources(ec);
out:
return ret;
}
static void __devexit eesoxscsi_remove(struct expansion_card *ec)
{
struct Scsi_Host *host = ecard_get_drvdata(ec);
struct eesoxscsi_info *info = (struct eesoxscsi_info *)host->hostdata;
ecard_set_drvdata(ec, NULL);
fas216_remove(host);
if (info->info.scsi.dma != NO_DMA)
free_dma(info->info.scsi.dma);
free_irq(ec->irq, info);
device_remove_file(&ec->dev, &dev_attr_bus_term);
iounmap(info->base);
fas216_release(host);
scsi_host_put(host);
ecard_release_resources(ec);
}
static const struct ecard_id eesoxscsi_cids[] = {
{ MANU_EESOX, PROD_EESOX_SCSI2 },
{ 0xffff, 0xffff },
};
static struct ecard_driver eesoxscsi_driver = {
.probe = eesoxscsi_probe,
.remove = __devexit_p(eesoxscsi_remove),
.id_table = eesoxscsi_cids,
.drv = {
.name = "eesoxscsi",
},
};
static int __init eesox_init(void)
{
return ecard_register_driver(&eesoxscsi_driver);
}
static void __exit eesox_exit(void)
{
ecard_remove_driver(&eesoxscsi_driver);
}
module_init(eesox_init);
module_exit(eesox_exit);
MODULE_AUTHOR("Russell King");
MODULE_DESCRIPTION("EESOX 'Fast' SCSI driver for Acorn machines");
module_param_array(term, int, NULL, 0);
MODULE_PARM_DESC(term, "SCSI bus termination");
MODULE_LICENSE("GPL");
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