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kernel-fxtec-pro1x/drivers/scsi/arm/cumana_2.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

554 lines
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/*
* linux/drivers/acorn/scsi/cumana_2.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.
*
* Changelog:
* 30-08-1997 RMK 0.0.0 Created, READONLY version.
* 22-01-1998 RMK 0.0.1 Updated to 2.1.80.
* 15-04-1998 RMK 0.0.1 Only do PIO if FAS216 will allow it.
* 02-05-1998 RMK 0.0.2 Updated & added DMA support.
* 27-06-1998 RMK Changed asm/delay.h to linux/delay.h
* 18-08-1998 RMK 0.0.3 Fixed synchronous transfer depth.
* 02-04-2000 RMK 0.0.4 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/dma.h>
#include <asm/ecard.h>
#include <asm/io.h>
#include <asm/pgtable.h>
#include "../scsi.h"
#include <scsi/scsi_host.h>
#include "fas216.h"
#include "scsi.h"
#include <scsi/scsicam.h>
#define CUMANASCSI2_STATUS (0x0000)
#define STATUS_INT (1 << 0)
#define STATUS_DRQ (1 << 1)
#define STATUS_LATCHED (1 << 3)
#define CUMANASCSI2_ALATCH (0x0014)
#define ALATCH_ENA_INT (3)
#define ALATCH_DIS_INT (2)
#define ALATCH_ENA_TERM (5)
#define ALATCH_DIS_TERM (4)
#define ALATCH_ENA_BIT32 (11)
#define ALATCH_DIS_BIT32 (10)
#define ALATCH_ENA_DMA (13)
#define ALATCH_DIS_DMA (12)
#define ALATCH_DMA_OUT (15)
#define ALATCH_DMA_IN (14)
#define CUMANASCSI2_PSEUDODMA (0x0200)
#define CUMANASCSI2_FAS216_OFFSET (0x0300)
#define CUMANASCSI2_FAS216_SHIFT 2
/*
* Version
*/
#define VERSION "1.00 (13/11/2002 2.5.47)"
/*
* 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 cumanascsi2_info {
FAS216_Info info;
struct expansion_card *ec;
void __iomem *base;
unsigned int terms; /* Terminator state */
struct scatterlist sg[NR_SG]; /* Scatter DMA list */
};
#define CSTATUS_IRQ (1 << 0)
#define CSTATUS_DRQ (1 << 1)
/* Prototype: void cumanascsi_2_irqenable(ec, irqnr)
* Purpose : Enable interrupts on Cumana SCSI 2 card
* Params : ec - expansion card structure
* : irqnr - interrupt number
*/
static void
cumanascsi_2_irqenable(struct expansion_card *ec, int irqnr)
{
struct cumanascsi2_info *info = ec->irq_data;
writeb(ALATCH_ENA_INT, info->base + CUMANASCSI2_ALATCH);
}
/* Prototype: void cumanascsi_2_irqdisable(ec, irqnr)
* Purpose : Disable interrupts on Cumana SCSI 2 card
* Params : ec - expansion card structure
* : irqnr - interrupt number
*/
static void
cumanascsi_2_irqdisable(struct expansion_card *ec, int irqnr)
{
struct cumanascsi2_info *info = ec->irq_data;
writeb(ALATCH_DIS_INT, info->base + CUMANASCSI2_ALATCH);
}
static const expansioncard_ops_t cumanascsi_2_ops = {
.irqenable = cumanascsi_2_irqenable,
.irqdisable = cumanascsi_2_irqdisable,
};
/* Prototype: void cumanascsi_2_terminator_ctl(host, on_off)
* Purpose : Turn the Cumana SCSI 2 terminators on or off
* Params : host - card to turn on/off
* : on_off - !0 to turn on, 0 to turn off
*/
static void
cumanascsi_2_terminator_ctl(struct Scsi_Host *host, int on_off)
{
struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;
if (on_off) {
info->terms = 1;
writeb(ALATCH_ENA_TERM, info->base + CUMANASCSI2_ALATCH);
} else {
info->terms = 0;
writeb(ALATCH_DIS_TERM, info->base + CUMANASCSI2_ALATCH);
}
}
/* Prototype: void cumanascsi_2_intr(irq, *dev_id, *regs)
* Purpose : handle interrupts from Cumana SCSI 2 card
* Params : irq - interrupt number
* dev_id - user-defined (Scsi_Host structure)
*/
static irqreturn_t
cumanascsi_2_intr(int irq, void *dev_id)
{
struct cumanascsi2_info *info = dev_id;
return fas216_intr(&info->info);
}
/* Prototype: fasdmatype_t cumanascsi_2_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
cumanascsi_2_dma_setup(struct Scsi_Host *host, struct scsi_pointer *SCp,
fasdmadir_t direction, fasdmatype_t min_type)
{
struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;
struct device *dev = scsi_get_device(host);
int dmach = info->info.scsi.dma;
writeb(ALATCH_DIS_DMA, info->base + CUMANASCSI2_ALATCH);
if (dmach != NO_DMA &&
(min_type == fasdma_real_all || SCp->this_residual >= 512)) {
int bufs, map_dir, dma_dir, alatch_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,
alatch_dir = ALATCH_DMA_OUT;
else
map_dir = DMA_FROM_DEVICE,
dma_dir = DMA_MODE_READ,
alatch_dir = ALATCH_DMA_IN;
dma_map_sg(dev, info->sg, bufs + 1, map_dir);
disable_dma(dmach);
set_dma_sg(dmach, info->sg, bufs + 1);
writeb(alatch_dir, info->base + CUMANASCSI2_ALATCH);
set_dma_mode(dmach, dma_dir);
enable_dma(dmach);
writeb(ALATCH_ENA_DMA, info->base + CUMANASCSI2_ALATCH);
writeb(ALATCH_DIS_BIT32, info->base + CUMANASCSI2_ALATCH);
return fasdma_real_all;
}
/*
* If we're not doing DMA,
* we'll do pseudo DMA
*/
return fasdma_pio;
}
/*
* Prototype: void cumanascsi_2_dma_pseudo(host, SCpnt, direction, transfer)
* Purpose : handles pseudo DMA
* Params : host - host
* SCpnt - command
* direction - DMA on to/off of card
* transfer - minimum number of bytes we expect to transfer
*/
static void
cumanascsi_2_dma_pseudo(struct Scsi_Host *host, struct scsi_pointer *SCp,
fasdmadir_t direction, int transfer)
{
struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;
unsigned int length;
unsigned char *addr;
length = SCp->this_residual;
addr = SCp->ptr;
if (direction == DMA_OUT)
#if 0
while (length > 1) {
unsigned long word;
unsigned int status = readb(info->base + CUMANASCSI2_STATUS);
if (status & STATUS_INT)
goto end;
if (!(status & STATUS_DRQ))
continue;
word = *addr | *(addr + 1) << 8;
writew(word, info->base + CUMANASCSI2_PSEUDODMA);
addr += 2;
length -= 2;
}
#else
printk ("PSEUDO_OUT???\n");
#endif
else {
if (transfer && (transfer & 255)) {
while (length >= 256) {
unsigned int status = readb(info->base + CUMANASCSI2_STATUS);
if (status & STATUS_INT)
return;
if (!(status & STATUS_DRQ))
continue;
readsw(info->base + CUMANASCSI2_PSEUDODMA,
addr, 256 >> 1);
addr += 256;
length -= 256;
}
}
while (length > 0) {
unsigned long word;
unsigned int status = readb(info->base + CUMANASCSI2_STATUS);
if (status & STATUS_INT)
return;
if (!(status & STATUS_DRQ))
continue;
word = readw(info->base + CUMANASCSI2_PSEUDODMA);
*addr++ = word;
if (--length > 0) {
*addr++ = word >> 8;
length --;
}
}
}
}
/* Prototype: int cumanascsi_2_dma_stop(host, SCpnt)
* Purpose : stops DMA/PIO
* Params : host - host
* SCpnt - command
*/
static void
cumanascsi_2_dma_stop(struct Scsi_Host *host, struct scsi_pointer *SCp)
{
struct cumanascsi2_info *info = (struct cumanascsi2_info *)host->hostdata;
if (info->info.scsi.dma != NO_DMA) {
writeb(ALATCH_DIS_DMA, info->base + CUMANASCSI2_ALATCH);
disable_dma(info->info.scsi.dma);
}
}
/* Prototype: const char *cumanascsi_2_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 *cumanascsi_2_info(struct Scsi_Host *host)
{
struct cumanascsi2_info *info = (struct cumanascsi2_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->terms ? "n" : "ff");
return string;
}
/* Prototype: int cumanascsi_2_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
cumanascsi_2_set_proc_info(struct Scsi_Host *host, char *buffer, int length)
{
int ret = length;
if (length >= 11 && strcmp(buffer, "CUMANASCSI2") == 0) {
buffer += 11;
length -= 11;
if (length >= 5 && strncmp(buffer, "term=", 5) == 0) {
if (buffer[5] == '1')
cumanascsi_2_terminator_ctl(host, 1);
else if (buffer[5] == '0')
cumanascsi_2_terminator_ctl(host, 0);
else
ret = -EINVAL;
} else
ret = -EINVAL;
} else
ret = -EINVAL;
return ret;
}
/* Prototype: int cumanascsi_2_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 cumanascsi_2_proc_info (struct Scsi_Host *host, char *buffer, char **start, off_t offset,
int length, int inout)
{
struct cumanascsi2_info *info;
char *p = buffer;
int pos;
if (inout == 1)
return cumanascsi_2_set_proc_info(host, buffer, length);
info = (struct cumanascsi2_info *)host->hostdata;
p += sprintf(p, "Cumana SCSI II driver v%s\n", VERSION);
p += fas216_print_host(&info->info, p);
p += sprintf(p, "Term : o%s\n",
info->terms ? "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 struct scsi_host_template cumanascsi2_template = {
.module = THIS_MODULE,
.proc_info = cumanascsi_2_proc_info,
.name = "Cumana SCSI II",
.info = cumanascsi_2_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 = "cumanascsi2",
};
static int __devinit
cumanascsi2_probe(struct expansion_card *ec, const struct ecard_id *id)
{
struct Scsi_Host *host;
struct cumanascsi2_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_MEMC);
reslen = ecard_resource_len(ec, ECARD_RES_MEMC);
base = ioremap(resbase, reslen);
if (!base) {
ret = -ENOMEM;
goto out_region;
}
host = scsi_host_alloc(&cumanascsi2_template,
sizeof(struct cumanascsi2_info));
if (!host) {
ret = -ENOMEM;
goto out_unmap;
}
ecard_set_drvdata(ec, host);
info = (struct cumanascsi2_info *)host->hostdata;
info->ec = ec;
info->base = base;
cumanascsi_2_terminator_ctl(host, term[ec->slot_no]);
info->info.scsi.io_base = base + CUMANASCSI2_FAS216_OFFSET;
info->info.scsi.io_shift = CUMANASCSI2_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_BS8 | 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 = cumanascsi_2_dma_setup;
info->info.dma.pseudo = cumanascsi_2_dma_pseudo;
info->info.dma.stop = cumanascsi_2_dma_stop;
ec->irqaddr = info->base + CUMANASCSI2_STATUS;
ec->irqmask = STATUS_INT;
ec->irq_data = info;
ec->ops = &cumanascsi_2_ops;
ret = fas216_init(host);
if (ret)
goto out_free;
ret = request_irq(ec->irq, cumanascsi_2_intr,
IRQF_DISABLED, "cumanascsi2", info);
if (ret) {
printk("scsi%d: IRQ%d not free: %d\n",
host->host_no, ec->irq, ret);
goto out_release;
}
if (info->info.scsi.dma != NO_DMA) {
if (request_dma(info->info.scsi.dma, "cumanascsi2")) {
printk("scsi%d: DMA%d not free, using PIO\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;
}
}
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_release:
fas216_release(host);
out_free:
scsi_host_put(host);
out_unmap:
iounmap(base);
out_region:
ecard_release_resources(ec);
out:
return ret;
}
static void __devexit cumanascsi2_remove(struct expansion_card *ec)
{
struct Scsi_Host *host = ecard_get_drvdata(ec);
struct cumanascsi2_info *info = (struct cumanascsi2_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);
iounmap(info->base);
fas216_release(host);
scsi_host_put(host);
ecard_release_resources(ec);
}
static const struct ecard_id cumanascsi2_cids[] = {
{ MANU_CUMANA, PROD_CUMANA_SCSI_2 },
{ 0xffff, 0xffff },
};
static struct ecard_driver cumanascsi2_driver = {
.probe = cumanascsi2_probe,
.remove = __devexit_p(cumanascsi2_remove),
.id_table = cumanascsi2_cids,
.drv = {
.name = "cumanascsi2",
},
};
static int __init cumanascsi2_init(void)
{
return ecard_register_driver(&cumanascsi2_driver);
}
static void __exit cumanascsi2_exit(void)
{
ecard_remove_driver(&cumanascsi2_driver);
}
module_init(cumanascsi2_init);
module_exit(cumanascsi2_exit);
MODULE_AUTHOR("Russell King");
MODULE_DESCRIPTION("Cumana SCSI-2 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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