linux/drivers/scsi/sun3_scsi_vme.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

585 lines
13 KiB
C

/*
* Sun3 SCSI stuff by Erik Verbruggen (erik@bigmama.xtdnet.nl)
*
* Sun3 DMA routines added by Sam Creasey (sammy@sammy.net)
*
* VME support added by Sam Creasey
*
* Adapted from sun3_scsi.c -- see there for other headers
*
* TODO: modify this driver to support multiple Sun3 SCSI VME boards
*
*/
#define AUTOSENSE
#include <linux/types.h>
#include <linux/stddef.h>
#include <linux/ctype.h>
#include <linux/delay.h>
#include <linux/module.h>
#include <linux/signal.h>
#include <linux/sched.h>
#include <linux/ioport.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <asm/io.h>
#include <asm/system.h>
#include <asm/sun3ints.h>
#include <asm/dvma.h>
#include <asm/idprom.h>
#include <asm/machines.h>
#define SUN3_SCSI_VME
#undef SUN3_SCSI_DEBUG
/* dma on! */
#define REAL_DMA
#include "scsi.h"
#include <scsi/scsi_host.h>
#include "sun3_scsi.h"
#include "NCR5380.h"
extern int sun3_map_test(unsigned long, char *);
#define USE_WRAPPER
/*#define RESET_BOOT */
#define DRIVER_SETUP
#define NDEBUG 0
/*
* BUG can be used to trigger a strange code-size related hang on 2.1 kernels
*/
#ifdef BUG
#undef RESET_BOOT
#undef DRIVER_SETUP
#endif
/* #define SUPPORT_TAGS */
//#define ENABLE_IRQ() enable_irq( SUN3_VEC_VMESCSI0 );
#define ENABLE_IRQ()
static irqreturn_t scsi_sun3_intr(int irq, void *dummy);
static inline unsigned char sun3scsi_read(int reg);
static inline void sun3scsi_write(int reg, int value);
static int setup_can_queue = -1;
module_param(setup_can_queue, int, 0);
static int setup_cmd_per_lun = -1;
module_param(setup_cmd_per_lun, int, 0);
static int setup_sg_tablesize = -1;
module_param(setup_sg_tablesize, int, 0);
#ifdef SUPPORT_TAGS
static int setup_use_tagged_queuing = -1;
module_param(setup_use_tagged_queuing, int, 0);
#endif
static int setup_hostid = -1;
module_param(setup_hostid, int, 0);
static Scsi_Cmnd *sun3_dma_setup_done = NULL;
#define AFTER_RESET_DELAY (HZ/2)
/* ms to wait after hitting dma regs */
#define SUN3_DMA_DELAY 10
/* dvma buffer to allocate -- 32k should hopefully be more than sufficient */
#define SUN3_DVMA_BUFSIZE 0xe000
/* minimum number of bytes to do dma on */
#define SUN3_DMA_MINSIZE 128
static volatile unsigned char *sun3_scsi_regp;
static volatile struct sun3_dma_regs *dregs;
#ifdef OLDDMA
static unsigned char *dmabuf = NULL; /* dma memory buffer */
#endif
static unsigned char *sun3_dma_orig_addr = NULL;
static unsigned long sun3_dma_orig_count = 0;
static int sun3_dma_active = 0;
static unsigned long last_residual = 0;
/*
* NCR 5380 register access functions
*/
static inline unsigned char sun3scsi_read(int reg)
{
return( sun3_scsi_regp[reg] );
}
static inline void sun3scsi_write(int reg, int value)
{
sun3_scsi_regp[reg] = value;
}
/*
* XXX: status debug
*/
static struct Scsi_Host *default_instance;
/*
* Function : int sun3scsi_detect(struct scsi_host_template * tpnt)
*
* Purpose : initializes mac NCR5380 driver based on the
* command line / compile time port and irq definitions.
*
* Inputs : tpnt - template for this SCSI adapter.
*
* Returns : 1 if a host adapter was found, 0 if not.
*
*/
static int sun3scsi_detect(struct scsi_host_template * tpnt)
{
unsigned long ioaddr, irq = 0;
static int called = 0;
struct Scsi_Host *instance;
int i;
unsigned long addrs[3] = { IOBASE_SUN3_VMESCSI,
IOBASE_SUN3_VMESCSI + 0x4000,
0 };
unsigned long vecs[3] = { SUN3_VEC_VMESCSI0,
SUN3_VEC_VMESCSI1,
0 };
/* check that this machine has an onboard 5380 */
switch(idprom->id_machtype) {
case SM_SUN3|SM_3_160:
case SM_SUN3|SM_3_260:
break;
default:
return 0;
}
if(called)
return 0;
tpnt->proc_name = "Sun3 5380 VME SCSI";
/* setup variables */
tpnt->can_queue =
(setup_can_queue > 0) ? setup_can_queue : CAN_QUEUE;
tpnt->cmd_per_lun =
(setup_cmd_per_lun > 0) ? setup_cmd_per_lun : CMD_PER_LUN;
tpnt->sg_tablesize =
(setup_sg_tablesize >= 0) ? setup_sg_tablesize : SG_TABLESIZE;
if (setup_hostid >= 0)
tpnt->this_id = setup_hostid;
else {
/* use 7 as default */
tpnt->this_id = 7;
}
ioaddr = 0;
for(i = 0; addrs[i] != 0; i++) {
unsigned char x;
ioaddr = (unsigned long)sun3_ioremap(addrs[i], PAGE_SIZE,
SUN3_PAGE_TYPE_VME16);
irq = vecs[i];
sun3_scsi_regp = (unsigned char *)ioaddr;
dregs = (struct sun3_dma_regs *)(((unsigned char *)ioaddr) + 8);
if(sun3_map_test((unsigned long)dregs, &x)) {
unsigned short oldcsr;
oldcsr = dregs->csr;
dregs->csr = 0;
udelay(SUN3_DMA_DELAY);
if(dregs->csr == 0x1400)
break;
dregs->csr = oldcsr;
}
iounmap((void *)ioaddr);
ioaddr = 0;
}
if(!ioaddr)
return 0;
#ifdef SUPPORT_TAGS
if (setup_use_tagged_queuing < 0)
setup_use_tagged_queuing = USE_TAGGED_QUEUING;
#endif
instance = scsi_register (tpnt, sizeof(struct NCR5380_hostdata));
if(instance == NULL)
return 0;
default_instance = instance;
instance->io_port = (unsigned long) ioaddr;
instance->irq = irq;
NCR5380_init(instance, 0);
instance->n_io_port = 32;
((struct NCR5380_hostdata *)instance->hostdata)->ctrl = 0;
if (request_irq(instance->irq, scsi_sun3_intr,
0, "Sun3SCSI-5380VME", NULL)) {
#ifndef REAL_DMA
printk("scsi%d: IRQ%d not free, interrupts disabled\n",
instance->host_no, instance->irq);
instance->irq = SCSI_IRQ_NONE;
#else
printk("scsi%d: IRQ%d not free, bailing out\n",
instance->host_no, instance->irq);
return 0;
#endif
}
printk("scsi%d: Sun3 5380 VME at port %lX irq", instance->host_no, instance->io_port);
if (instance->irq == SCSI_IRQ_NONE)
printk ("s disabled");
else
printk (" %d", instance->irq);
printk(" options CAN_QUEUE=%d CMD_PER_LUN=%d release=%d",
instance->can_queue, instance->cmd_per_lun,
SUN3SCSI_PUBLIC_RELEASE);
printk("\nscsi%d:", instance->host_no);
NCR5380_print_options(instance);
printk("\n");
dregs->csr = 0;
udelay(SUN3_DMA_DELAY);
dregs->csr = CSR_SCSI | CSR_FIFO | CSR_INTR;
udelay(SUN3_DMA_DELAY);
dregs->fifo_count = 0;
dregs->fifo_count_hi = 0;
dregs->dma_addr_hi = 0;
dregs->dma_addr_lo = 0;
dregs->dma_count_hi = 0;
dregs->dma_count_lo = 0;
dregs->ivect = VME_DATA24 | (instance->irq & 0xff);
called = 1;
#ifdef RESET_BOOT
sun3_scsi_reset_boot(instance);
#endif
return 1;
}
int sun3scsi_release (struct Scsi_Host *shpnt)
{
if (shpnt->irq != SCSI_IRQ_NONE)
free_irq (shpnt->irq, NULL);
iounmap((void *)sun3_scsi_regp);
return 0;
}
#ifdef RESET_BOOT
/*
* Our 'bus reset on boot' function
*/
static void sun3_scsi_reset_boot(struct Scsi_Host *instance)
{
unsigned long end;
NCR5380_local_declare();
NCR5380_setup(instance);
/*
* Do a SCSI reset to clean up the bus during initialization. No
* messing with the queues, interrupts, or locks necessary here.
*/
printk( "Sun3 SCSI: resetting the SCSI bus..." );
/* switch off SCSI IRQ - catch an interrupt without IRQ bit set else */
// sun3_disable_irq( IRQ_SUN3_SCSI );
/* get in phase */
NCR5380_write( TARGET_COMMAND_REG,
PHASE_SR_TO_TCR( NCR5380_read(STATUS_REG) ));
/* assert RST */
NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE | ICR_ASSERT_RST );
/* The min. reset hold time is 25us, so 40us should be enough */
udelay( 50 );
/* reset RST and interrupt */
NCR5380_write( INITIATOR_COMMAND_REG, ICR_BASE );
NCR5380_read( RESET_PARITY_INTERRUPT_REG );
for( end = jiffies + AFTER_RESET_DELAY; time_before(jiffies, end); )
barrier();
/* switch on SCSI IRQ again */
// sun3_enable_irq( IRQ_SUN3_SCSI );
printk( " done\n" );
}
#endif
static const char * sun3scsi_info (struct Scsi_Host *spnt) {
return "";
}
// safe bits for the CSR
#define CSR_GOOD 0x060f
static irqreturn_t scsi_sun3_intr(int irq, void *dummy)
{
unsigned short csr = dregs->csr;
int handled = 0;
dregs->csr &= ~CSR_DMA_ENABLE;
#ifdef SUN3_SCSI_DEBUG
printk("scsi_intr csr %x\n", csr);
#endif
if(csr & ~CSR_GOOD) {
if(csr & CSR_DMA_BUSERR) {
printk("scsi%d: bus error in dma\n", default_instance->host_no);
#ifdef SUN3_SCSI_DEBUG
printk("scsi: residual %x count %x addr %p dmaaddr %x\n",
dregs->fifo_count,
dregs->dma_count_lo | (dregs->dma_count_hi << 16),
sun3_dma_orig_addr,
dregs->dma_addr_lo | (dregs->dma_addr_hi << 16));
#endif
}
if(csr & CSR_DMA_CONFLICT) {
printk("scsi%d: dma conflict\n", default_instance->host_no);
}
handled = 1;
}
if(csr & (CSR_SDB_INT | CSR_DMA_INT)) {
NCR5380_intr(irq, dummy);
handled = 1;
}
return IRQ_RETVAL(handled);
}
/*
* Debug stuff - to be called on NMI, or sysrq key. Use at your own risk;
* reentering NCR5380_print_status seems to have ugly side effects
*/
/* this doesn't seem to get used at all -- sam */
#if 0
void sun3_sun3_debug (void)
{
unsigned long flags;
NCR5380_local_declare();
if (default_instance) {
local_irq_save(flags);
NCR5380_print_status(default_instance);
local_irq_restore(flags);
}
}
#endif
/* sun3scsi_dma_setup() -- initialize the dma controller for a read/write */
static unsigned long sun3scsi_dma_setup(void *data, unsigned long count, int write_flag)
{
void *addr;
if(sun3_dma_orig_addr != NULL)
dvma_unmap(sun3_dma_orig_addr);
// addr = sun3_dvma_page((unsigned long)data, (unsigned long)dmabuf);
addr = (void *)dvma_map_vme((unsigned long) data, count);
sun3_dma_orig_addr = addr;
sun3_dma_orig_count = count;
#ifdef SUN3_SCSI_DEBUG
printk("scsi: dma_setup addr %p count %x\n", addr, count);
#endif
// dregs->fifo_count = 0;
#if 0
/* reset fifo */
dregs->csr &= ~CSR_FIFO;
dregs->csr |= CSR_FIFO;
#endif
/* set direction */
if(write_flag)
dregs->csr |= CSR_SEND;
else
dregs->csr &= ~CSR_SEND;
/* reset fifo */
// dregs->csr &= ~CSR_FIFO;
// dregs->csr |= CSR_FIFO;
dregs->csr |= CSR_PACK_ENABLE;
dregs->dma_addr_hi = ((unsigned long)addr >> 16);
dregs->dma_addr_lo = ((unsigned long)addr & 0xffff);
dregs->dma_count_hi = 0;
dregs->dma_count_lo = 0;
dregs->fifo_count_hi = 0;
dregs->fifo_count = 0;
#ifdef SUN3_SCSI_DEBUG
printk("scsi: dma_setup done csr %x\n", dregs->csr);
#endif
return count;
}
static inline unsigned long sun3scsi_dma_residual(struct Scsi_Host *instance)
{
return last_residual;
}
static inline unsigned long sun3scsi_dma_xfer_len(unsigned long wanted, Scsi_Cmnd *cmd,
int write_flag)
{
if(blk_fs_request(cmd->request))
return wanted;
else
return 0;
}
static int sun3scsi_dma_start(unsigned long count, char *data)
{
unsigned short csr;
csr = dregs->csr;
#ifdef SUN3_SCSI_DEBUG
printk("scsi: dma_start data %p count %x csr %x fifo %x\n", data, count, csr, dregs->fifo_count);
#endif
dregs->dma_count_hi = (sun3_dma_orig_count >> 16);
dregs->dma_count_lo = (sun3_dma_orig_count & 0xffff);
dregs->fifo_count_hi = (sun3_dma_orig_count >> 16);
dregs->fifo_count = (sun3_dma_orig_count & 0xffff);
// if(!(csr & CSR_DMA_ENABLE))
// dregs->csr |= CSR_DMA_ENABLE;
return 0;
}
/* clean up after our dma is done */
static int sun3scsi_dma_finish(int write_flag)
{
unsigned short fifo;
int ret = 0;
sun3_dma_active = 0;
dregs->csr &= ~CSR_DMA_ENABLE;
fifo = dregs->fifo_count;
if(write_flag) {
if((fifo > 0) && (fifo < sun3_dma_orig_count))
fifo++;
}
last_residual = fifo;
#ifdef SUN3_SCSI_DEBUG
printk("scsi: residual %x total %x\n", fifo, sun3_dma_orig_count);
#endif
/* empty bytes from the fifo which didn't make it */
if((!write_flag) && (dregs->csr & CSR_LEFT)) {
unsigned char *vaddr;
#ifdef SUN3_SCSI_DEBUG
printk("scsi: got left over bytes\n");
#endif
vaddr = (unsigned char *)dvma_vmetov(sun3_dma_orig_addr);
vaddr += (sun3_dma_orig_count - fifo);
vaddr--;
switch(dregs->csr & CSR_LEFT) {
case CSR_LEFT_3:
*vaddr = (dregs->bpack_lo & 0xff00) >> 8;
vaddr--;
case CSR_LEFT_2:
*vaddr = (dregs->bpack_hi & 0x00ff);
vaddr--;
case CSR_LEFT_1:
*vaddr = (dregs->bpack_hi & 0xff00) >> 8;
break;
}
}
dvma_unmap(sun3_dma_orig_addr);
sun3_dma_orig_addr = NULL;
dregs->dma_addr_hi = 0;
dregs->dma_addr_lo = 0;
dregs->dma_count_hi = 0;
dregs->dma_count_lo = 0;
dregs->fifo_count = 0;
dregs->fifo_count_hi = 0;
dregs->csr &= ~CSR_SEND;
// dregs->csr |= CSR_DMA_ENABLE;
#if 0
/* reset fifo */
dregs->csr &= ~CSR_FIFO;
dregs->csr |= CSR_FIFO;
#endif
sun3_dma_setup_done = NULL;
return ret;
}
#include "sun3_NCR5380.c"
static struct scsi_host_template driver_template = {
.name = SUN3_SCSI_NAME,
.detect = sun3scsi_detect,
.release = sun3scsi_release,
.info = sun3scsi_info,
.queuecommand = sun3scsi_queue_command,
.eh_abort_handler = sun3scsi_abort,
.eh_bus_reset_handler = sun3scsi_bus_reset,
.can_queue = CAN_QUEUE,
.this_id = 7,
.sg_tablesize = SG_TABLESIZE,
.cmd_per_lun = CMD_PER_LUN,
.use_clustering = DISABLE_CLUSTERING
};
#include "scsi_module.c"