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alistair23-linux/drivers/scsi/mac_esp.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

752 lines
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/*
* 68k mac 53c9[46] scsi driver
*
* copyright (c) 1998, David Weis weisd3458@uni.edu
*
* debugging on Quadra 800 and 660AV Michael Schmitz, Dave Kilzer 7/98
*
* based loosely on cyber_esp.c
*/
/* these are unused for now */
#define myreadl(addr) (*(volatile unsigned int *) (addr))
#define mywritel(b, addr) ((*(volatile unsigned int *) (addr)) = (b))
#include <linux/kernel.h>
#include <linux/delay.h>
#include <linux/types.h>
#include <linux/ctype.h>
#include <linux/string.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/proc_fs.h>
#include <linux/stat.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include "scsi.h"
#include <scsi/scsi_host.h>
#include "NCR53C9x.h"
#include <asm/io.h>
#include <asm/setup.h>
#include <asm/irq.h>
#include <asm/macints.h>
#include <asm/machw.h>
#include <asm/mac_via.h>
#include <asm/pgtable.h>
#include <asm/macintosh.h>
/* #define DEBUG_MAC_ESP */
extern void esp_handle(struct NCR_ESP *esp);
extern void mac_esp_intr(int irq, void *dev_id);
static int dma_bytes_sent(struct NCR_ESP * esp, int fifo_count);
static int dma_can_transfer(struct NCR_ESP * esp, Scsi_Cmnd *sp);
static void dma_dump_state(struct NCR_ESP * esp);
static void dma_init_read(struct NCR_ESP * esp, char * vaddress, int length);
static void dma_init_write(struct NCR_ESP * esp, char * vaddress, int length);
static void dma_ints_off(struct NCR_ESP * esp);
static void dma_ints_on(struct NCR_ESP * esp);
static int dma_irq_p(struct NCR_ESP * esp);
static int dma_irq_p_quick(struct NCR_ESP * esp);
static void dma_led_off(struct NCR_ESP * esp);
static void dma_led_on(struct NCR_ESP *esp);
static int dma_ports_p(struct NCR_ESP *esp);
static void dma_setup(struct NCR_ESP * esp, __u32 addr, int count, int write);
static void dma_setup_quick(struct NCR_ESP * esp, __u32 addr, int count, int write);
static int esp_dafb_dma_irq_p(struct NCR_ESP * espdev);
static int esp_iosb_dma_irq_p(struct NCR_ESP * espdev);
static volatile unsigned char cmd_buffer[16];
/* This is where all commands are put
* before they are transferred to the ESP chip
* via PIO.
*/
static int esp_initialized = 0;
static int setup_num_esps = -1;
static int setup_disconnect = -1;
static int setup_nosync = -1;
static int setup_can_queue = -1;
static int setup_cmd_per_lun = -1;
static int setup_sg_tablesize = -1;
#ifdef SUPPORT_TAGS
static int setup_use_tagged_queuing = -1;
#endif
static int setup_hostid = -1;
/*
* Experimental ESP inthandler; check macints.c to make sure dev_id is
* set up properly!
*/
void mac_esp_intr(int irq, void *dev_id)
{
struct NCR_ESP *esp = (struct NCR_ESP *) dev_id;
int irq_p = 0;
/* Handle the one ESP interrupt showing at this IRQ level. */
if(((esp)->irq & 0xff) == irq) {
/*
* Debug ..
*/
irq_p = esp->dma_irq_p(esp);
printk("mac_esp: irq_p %x current %p disconnected %p\n",
irq_p, esp->current_SC, esp->disconnected_SC);
/*
* Mac: if we're here, it's an ESP interrupt for sure!
*/
if((esp->current_SC || esp->disconnected_SC)) {
esp->dma_ints_off(esp);
ESPIRQ(("I%d(", esp->esp_id));
esp_handle(esp);
ESPIRQ((")"));
esp->dma_ints_on(esp);
}
}
}
/*
* Debug hooks; use for playing with the interrupt flag testing and interrupt
* acknowledge on the various machines
*/
void scsi_esp_polled(int irq, void *dev_id)
{
if (esp_initialized == 0)
return;
mac_esp_intr(irq, dev_id);
}
void fake_intr(int irq, void *dev_id)
{
#ifdef DEBUG_MAC_ESP
printk("mac_esp: got irq\n");
#endif
mac_esp_intr(irq, dev_id);
}
irqreturn_t fake_drq(int irq, void *dev_id)
{
printk("mac_esp: got drq\n");
return IRQ_HANDLED;
}
#define DRIVER_SETUP
/*
* Function : mac_esp_setup(char *str)
*
* Purpose : booter command line initialization of the overrides array,
*
* Inputs : str - parameters, separated by commas.
*
* Currently unused in the new driver; need to add settable parameters to the
* detect function.
*
*/
static int __init mac_esp_setup(char *str) {
#ifdef DRIVER_SETUP
/* Format of mac53c9x parameter is:
* mac53c9x=<num_esps>,<disconnect>,<nosync>,<can_queue>,<cmd_per_lun>,<sg_tablesize>,<hostid>,<use_tags>
* Negative values mean don't change.
*/
char *this_opt;
long opt;
this_opt = strsep (&str, ",");
if(this_opt) {
opt = simple_strtol( this_opt, NULL, 0 );
if (opt >= 0 && opt <= 2)
setup_num_esps = opt;
else if (opt > 2)
printk( "mac_esp_setup: invalid number of hosts %ld !\n", opt );
this_opt = strsep (&str, ",");
}
if(this_opt) {
opt = simple_strtol( this_opt, NULL, 0 );
if (opt > 0)
setup_disconnect = opt;
this_opt = strsep (&str, ",");
}
if(this_opt) {
opt = simple_strtol( this_opt, NULL, 0 );
if (opt >= 0)
setup_nosync = opt;
this_opt = strsep (&str, ",");
}
if(this_opt) {
opt = simple_strtol( this_opt, NULL, 0 );
if (opt > 0)
setup_can_queue = opt;
this_opt = strsep (&str, ",");
}
if(this_opt) {
opt = simple_strtol( this_opt, NULL, 0 );
if (opt > 0)
setup_cmd_per_lun = opt;
this_opt = strsep (&str, ",");
}
if(this_opt) {
opt = simple_strtol( this_opt, NULL, 0 );
if (opt >= 0) {
setup_sg_tablesize = opt;
/* Must be <= SG_ALL (255) */
if (setup_sg_tablesize > SG_ALL)
setup_sg_tablesize = SG_ALL;
}
this_opt = strsep (&str, ",");
}
if(this_opt) {
opt = simple_strtol( this_opt, NULL, 0 );
/* Must be between 0 and 7 */
if (opt >= 0 && opt <= 7)
setup_hostid = opt;
else if (opt > 7)
printk( "mac_esp_setup: invalid host ID %ld !\n", opt);
this_opt = strsep (&str, ",");
}
#ifdef SUPPORT_TAGS
if(this_opt) {
opt = simple_strtol( this_opt, NULL, 0 );
if (opt >= 0)
setup_use_tagged_queuing = !!opt;
}
#endif
#endif
return 1;
}
__setup("mac53c9x=", mac_esp_setup);
/*
* ESP address 'detection'
*/
unsigned long get_base(int chip_num)
{
/*
* using the chip_num and mac model, figure out where the
* chips are mapped
*/
unsigned long io_base = 0x50f00000;
unsigned int second_offset = 0x402;
unsigned long scsi_loc = 0;
switch (macintosh_config->scsi_type) {
/* 950, 900, 700 */
case MAC_SCSI_QUADRA2:
scsi_loc = io_base + 0xf000 + ((chip_num == 0) ? 0 : second_offset);
break;
/* av's */
case MAC_SCSI_QUADRA3:
scsi_loc = io_base + 0x18000 + ((chip_num == 0) ? 0 : second_offset);
break;
/* most quadra/centris models are like this */
case MAC_SCSI_QUADRA:
scsi_loc = io_base + 0x10000;
break;
default:
printk("mac_esp: get_base: hit default!\n");
scsi_loc = io_base + 0x10000;
break;
} /* switch */
printk("mac_esp: io base at 0x%lx\n", scsi_loc);
return scsi_loc;
}
/*
* Model dependent ESP setup
*/
int mac_esp_detect(struct scsi_host_template * tpnt)
{
int quick = 0;
int chipnum, chipspresent = 0;
#if 0
unsigned long timeout;
#endif
if (esp_initialized > 0)
return -ENODEV;
/* what do we have in this machine... */
if (MACHW_PRESENT(MAC_SCSI_96)) {
chipspresent ++;
}
if (MACHW_PRESENT(MAC_SCSI_96_2)) {
chipspresent ++;
}
/* number of ESPs present ? */
if (setup_num_esps >= 0) {
if (chipspresent >= setup_num_esps)
chipspresent = setup_num_esps;
else
printk("mac_esp_detect: num_hosts detected %d setup %d \n",
chipspresent, setup_num_esps);
}
/* TODO: add disconnect / nosync flags */
/* setup variables */
tpnt->can_queue =
(setup_can_queue > 0) ? setup_can_queue : 7;
tpnt->cmd_per_lun =
(setup_cmd_per_lun > 0) ? setup_cmd_per_lun : 1;
tpnt->sg_tablesize =
(setup_sg_tablesize >= 0) ? setup_sg_tablesize : SG_ALL;
if (setup_hostid >= 0)
tpnt->this_id = setup_hostid;
else {
/* use 7 as default */
tpnt->this_id = 7;
}
#ifdef SUPPORT_TAGS
if (setup_use_tagged_queuing < 0)
setup_use_tagged_queuing = DEFAULT_USE_TAGGED_QUEUING;
#endif
for (chipnum = 0; chipnum < chipspresent; chipnum ++) {
struct NCR_ESP * esp;
esp = esp_allocate(tpnt, (void *) NULL);
esp->eregs = (struct ESP_regs *) get_base(chipnum);
esp->dma_irq_p = &esp_dafb_dma_irq_p;
if (chipnum == 0) {
if (macintosh_config->scsi_type == MAC_SCSI_QUADRA) {
/* most machines except those below :-) */
quick = 1;
esp->dma_irq_p = &esp_iosb_dma_irq_p;
} else if (macintosh_config->scsi_type == MAC_SCSI_QUADRA3) {
/* mostly av's */
quick = 0;
} else {
/* q950, 900, 700 */
quick = 1;
out_be32(0xf9800024, 0x1d1);
esp->dregs = (void *) 0xf9800024;
}
} else { /* chipnum */
quick = 1;
out_be32(0xf9800028, 0x1d1);
esp->dregs = (void *) 0xf9800028;
} /* chipnum == 0 */
/* use pio for command bytes; pio for message/data: TBI */
esp->do_pio_cmds = 1;
/* Set the command buffer */
esp->esp_command = (volatile unsigned char*) cmd_buffer;
esp->esp_command_dvma = (__u32) cmd_buffer;
/* various functions */
esp->dma_bytes_sent = &dma_bytes_sent;
esp->dma_can_transfer = &dma_can_transfer;
esp->dma_dump_state = &dma_dump_state;
esp->dma_init_read = NULL;
esp->dma_init_write = NULL;
esp->dma_ints_off = &dma_ints_off;
esp->dma_ints_on = &dma_ints_on;
esp->dma_ports_p = &dma_ports_p;
/* Optional functions */
esp->dma_barrier = NULL;
esp->dma_drain = NULL;
esp->dma_invalidate = NULL;
esp->dma_irq_entry = NULL;
esp->dma_irq_exit = NULL;
esp->dma_led_on = NULL;
esp->dma_led_off = NULL;
esp->dma_poll = NULL;
esp->dma_reset = NULL;
/* SCSI chip speed */
/* below esp->cfreq = 40000000; */
if (quick) {
/* 'quick' means there's handshake glue logic like in the 5380 case */
esp->dma_setup = &dma_setup_quick;
} else {
esp->dma_setup = &dma_setup;
}
if (chipnum == 0) {
esp->irq = IRQ_MAC_SCSI;
request_irq(IRQ_MAC_SCSI, esp_intr, 0, "Mac ESP SCSI", esp->ehost);
#if 0 /* conflicts with IOP ADB */
request_irq(IRQ_MAC_SCSIDRQ, fake_drq, 0, "Mac ESP DRQ", esp->ehost);
#endif
if (macintosh_config->scsi_type == MAC_SCSI_QUADRA) {
esp->cfreq = 16500000;
} else {
esp->cfreq = 25000000;
}
} else { /* chipnum == 1 */
esp->irq = IRQ_MAC_SCSIDRQ;
#if 0 /* conflicts with IOP ADB */
request_irq(IRQ_MAC_SCSIDRQ, esp_intr, 0, "Mac ESP SCSI 2", esp->ehost);
#endif
esp->cfreq = 25000000;
}
if (quick) {
printk("esp: using quick version\n");
}
printk("esp: addr at 0x%p\n", esp->eregs);
esp->scsi_id = 7;
esp->diff = 0;
esp_initialize(esp);
} /* for chipnum */
if (chipspresent)
printk("\nmac_esp: %d esp controllers found\n", chipspresent);
esp_initialized = chipspresent;
return chipspresent;
}
static int mac_esp_release(struct Scsi_Host *shost)
{
if (shost->irq)
free_irq(shost->irq, NULL);
if (shost->io_port && shost->n_io_port)
release_region(shost->io_port, shost->n_io_port);
scsi_unregister(shost);
return 0;
}
/*
* I've been wondering what this is supposed to do, for some time. Talking
* to Allen Briggs: These machines have an extra register someplace where the
* DRQ pin of the ESP can be monitored. That isn't useful for determining
* anything else (such as reselect interrupt or other magic) though.
* Maybe make the semantics should be changed like
* if (esp->current_SC)
* ... check DRQ flag ...
* else
* ... disconnected, check pending VIA interrupt ...
*
* There's a problem with using the dabf flag or mac_irq_pending() here: both
* seem to return 1 even though no interrupt is currently pending, resulting
* in esp_exec_cmd() holding off the next command, and possibly infinite loops
* in esp_intr().
* Short term fix: just use esp_status & ESP_STAT_INTR here, as long as we
* use simple PIO. The DRQ status will be important when implementing pseudo
* DMA mode (set up ESP transfer count, return, do a batch of bytes in PIO or
* 'hardware handshake' mode upon DRQ).
* If you plan on changing this (i.e. to save the esp_status register access in
* favor of a VIA register access or a shadow register for the IFR), make sure
* to try a debug version of this first to monitor what registers would be a good
* indicator of the ESP interrupt.
*/
static int esp_dafb_dma_irq_p(struct NCR_ESP * esp)
{
unsigned int ret;
int sreg = esp_read(esp->eregs->esp_status);
#ifdef DEBUG_MAC_ESP
printk("mac_esp: esp_dafb_dma_irq_p dafb %d irq %d\n",
readl(esp->dregs), mac_irq_pending(IRQ_MAC_SCSI));
#endif
sreg &= ESP_STAT_INTR;
/*
* maybe working; this is essentially what's used for iosb_dma_irq_p
*/
if (sreg)
return 1;
else
return 0;
/*
* didn't work ...
*/
#if 0
if (esp->current_SC)
ret = readl(esp->dregs) & 0x200;
else if (esp->disconnected_SC)
ret = 1; /* sreg ?? */
else
ret = mac_irq_pending(IRQ_MAC_SCSI);
return(ret);
#endif
}
/*
* See above: testing mac_irq_pending always returned 8 (SCSI IRQ) regardless
* of the actual ESP status.
*/
static int esp_iosb_dma_irq_p(struct NCR_ESP * esp)
{
int ret = mac_irq_pending(IRQ_MAC_SCSI) || mac_irq_pending(IRQ_MAC_SCSIDRQ);
int sreg = esp_read(esp->eregs->esp_status);
#ifdef DEBUG_MAC_ESP
printk("mac_esp: dma_irq_p drq %d irq %d sreg %x curr %p disc %p\n",
mac_irq_pending(IRQ_MAC_SCSIDRQ), mac_irq_pending(IRQ_MAC_SCSI),
sreg, esp->current_SC, esp->disconnected_SC);
#endif
sreg &= ESP_STAT_INTR;
if (sreg)
return (sreg);
else
return 0;
}
/*
* This seems to be OK for PIO at least ... usually 0 after PIO.
*/
static int dma_bytes_sent(struct NCR_ESP * esp, int fifo_count)
{
#ifdef DEBUG_MAC_ESP
printk("mac_esp: dma bytes sent = %x\n", fifo_count);
#endif
return fifo_count;
}
/*
* dma_can_transfer is used to switch between DMA and PIO, if DMA (pseudo)
* is ever implemented. Returning 0 here will use PIO.
*/
static int dma_can_transfer(struct NCR_ESP * esp, Scsi_Cmnd * sp)
{
unsigned long sz = sp->SCp.this_residual;
#if 0 /* no DMA yet; make conditional */
if (sz > 0x10000000) {
sz = 0x10000000;
}
printk("mac_esp: dma can transfer = 0lx%x\n", sz);
#else
#ifdef DEBUG_MAC_ESP
printk("mac_esp: pio to transfer = %ld\n", sz);
#endif
sz = 0;
#endif
return sz;
}
/*
* Not yet ...
*/
static void dma_dump_state(struct NCR_ESP * esp)
{
#ifdef DEBUG_MAC_ESP
printk("mac_esp: dma_dump_state: called\n");
#endif
#if 0
ESPLOG(("esp%d: dma -- cond_reg<%02x>\n",
esp->esp_id, ((struct mac_dma_registers *)
(esp->dregs))->cond_reg));
#endif
}
/*
* DMA setup: should be used to set up the ESP transfer count for pseudo
* DMA transfers; need a DRQ transfer function to do the actual transfer
*/
static void dma_init_read(struct NCR_ESP * esp, char * vaddress, int length)
{
printk("mac_esp: dma_init_read\n");
}
static void dma_init_write(struct NCR_ESP * esp, char * vaddress, int length)
{
printk("mac_esp: dma_init_write\n");
}
static void dma_ints_off(struct NCR_ESP * esp)
{
disable_irq(esp->irq);
}
static void dma_ints_on(struct NCR_ESP * esp)
{
enable_irq(esp->irq);
}
/*
* generic dma_irq_p(), unused
*/
static int dma_irq_p(struct NCR_ESP * esp)
{
int i = esp_read(esp->eregs->esp_status);
#ifdef DEBUG_MAC_ESP
printk("mac_esp: dma_irq_p status %d\n", i);
#endif
return (i & ESP_STAT_INTR);
}
static int dma_irq_p_quick(struct NCR_ESP * esp)
{
/*
* Copied from iosb_dma_irq_p()
*/
int ret = mac_irq_pending(IRQ_MAC_SCSI) || mac_irq_pending(IRQ_MAC_SCSIDRQ);
int sreg = esp_read(esp->eregs->esp_status);
#ifdef DEBUG_MAC_ESP
printk("mac_esp: dma_irq_p drq %d irq %d sreg %x curr %p disc %p\n",
mac_irq_pending(IRQ_MAC_SCSIDRQ), mac_irq_pending(IRQ_MAC_SCSI),
sreg, esp->current_SC, esp->disconnected_SC);
#endif
sreg &= ESP_STAT_INTR;
if (sreg)
return (sreg);
else
return 0;
}
static void dma_led_off(struct NCR_ESP * esp)
{
#ifdef DEBUG_MAC_ESP
printk("mac_esp: dma_led_off: called\n");
#endif
}
static void dma_led_on(struct NCR_ESP * esp)
{
#ifdef DEBUG_MAC_ESP
printk("mac_esp: dma_led_on: called\n");
#endif
}
static int dma_ports_p(struct NCR_ESP * esp)
{
return 0;
}
static void dma_setup(struct NCR_ESP * esp, __u32 addr, int count, int write)
{
#ifdef DEBUG_MAC_ESP
printk("mac_esp: dma_setup\n");
#endif
if (write) {
dma_init_read(esp, (char *) addr, count);
} else {
dma_init_write(esp, (char *) addr, count);
}
}
static void dma_setup_quick(struct NCR_ESP * esp, __u32 addr, int count, int write)
{
#ifdef DEBUG_MAC_ESP
printk("mac_esp: dma_setup_quick\n");
#endif
}
static struct scsi_host_template driver_template = {
.proc_name = "mac_esp",
.name = "Mac 53C9x SCSI",
.detect = mac_esp_detect,
.slave_alloc = esp_slave_alloc,
.slave_destroy = esp_slave_destroy,
.release = mac_esp_release,
.info = esp_info,
.queuecommand = esp_queue,
.eh_abort_handler = esp_abort,
.eh_bus_reset_handler = esp_reset,
.can_queue = 7,
.this_id = 7,
.sg_tablesize = SG_ALL,
.cmd_per_lun = 1,
.use_clustering = DISABLE_CLUSTERING
};
#include "scsi_module.c"
MODULE_LICENSE("GPL");
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