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linux/drivers/scsi/gvp11.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

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#include <linux/types.h>
#include <linux/mm.h>
#include <linux/blkdev.h>
#include <linux/sched.h>
#include <linux/init.h>
#include <linux/interrupt.h>
#include <asm/setup.h>
#include <asm/page.h>
#include <asm/pgtable.h>
#include <asm/amigaints.h>
#include <asm/amigahw.h>
#include <linux/zorro.h>
#include <asm/irq.h>
#include <linux/spinlock.h>
#include "scsi.h"
#include <scsi/scsi_host.h>
#include "wd33c93.h"
#include "gvp11.h"
#include<linux/stat.h>
#define DMA(ptr) ((gvp11_scsiregs *)((ptr)->base))
#define HDATA(ptr) ((struct WD33C93_hostdata *)((ptr)->hostdata))
static irqreturn_t gvp11_intr (int irq, void *_instance)
{
unsigned long flags;
unsigned int status;
struct Scsi_Host *instance = (struct Scsi_Host *)_instance;
status = DMA(instance)->CNTR;
if (!(status & GVP11_DMAC_INT_PENDING))
return IRQ_NONE;
spin_lock_irqsave(instance->host_lock, flags);
wd33c93_intr(instance);
spin_unlock_irqrestore(instance->host_lock, flags);
return IRQ_HANDLED;
}
static int gvp11_xfer_mask = 0;
void gvp11_setup (char *str, int *ints)
{
gvp11_xfer_mask = ints[1];
}
static int dma_setup(struct scsi_cmnd *cmd, int dir_in)
{
unsigned short cntr = GVP11_DMAC_INT_ENABLE;
unsigned long addr = virt_to_bus(cmd->SCp.ptr);
int bank_mask;
static int scsi_alloc_out_of_range = 0;
/* use bounce buffer if the physical address is bad */
if (addr & HDATA(cmd->device->host)->dma_xfer_mask ||
(!dir_in && mm_end_of_chunk (addr, cmd->SCp.this_residual)))
{
HDATA(cmd->device->host)->dma_bounce_len = (cmd->SCp.this_residual + 511)
& ~0x1ff;
if( !scsi_alloc_out_of_range ) {
HDATA(cmd->device->host)->dma_bounce_buffer =
kmalloc (HDATA(cmd->device->host)->dma_bounce_len, GFP_KERNEL);
HDATA(cmd->device->host)->dma_buffer_pool = BUF_SCSI_ALLOCED;
}
if (scsi_alloc_out_of_range ||
!HDATA(cmd->device->host)->dma_bounce_buffer) {
HDATA(cmd->device->host)->dma_bounce_buffer =
amiga_chip_alloc(HDATA(cmd->device->host)->dma_bounce_len,
"GVP II SCSI Bounce Buffer");
if(!HDATA(cmd->device->host)->dma_bounce_buffer)
{
HDATA(cmd->device->host)->dma_bounce_len = 0;
return 1;
}
HDATA(cmd->device->host)->dma_buffer_pool = BUF_CHIP_ALLOCED;
}
/* check if the address of the bounce buffer is OK */
addr = virt_to_bus(HDATA(cmd->device->host)->dma_bounce_buffer);
if (addr & HDATA(cmd->device->host)->dma_xfer_mask) {
/* fall back to Chip RAM if address out of range */
if( HDATA(cmd->device->host)->dma_buffer_pool == BUF_SCSI_ALLOCED) {
kfree (HDATA(cmd->device->host)->dma_bounce_buffer);
scsi_alloc_out_of_range = 1;
} else {
amiga_chip_free (HDATA(cmd->device->host)->dma_bounce_buffer);
}
HDATA(cmd->device->host)->dma_bounce_buffer =
amiga_chip_alloc(HDATA(cmd->device->host)->dma_bounce_len,
"GVP II SCSI Bounce Buffer");
if(!HDATA(cmd->device->host)->dma_bounce_buffer)
{
HDATA(cmd->device->host)->dma_bounce_len = 0;
return 1;
}
addr = virt_to_bus(HDATA(cmd->device->host)->dma_bounce_buffer);
HDATA(cmd->device->host)->dma_buffer_pool = BUF_CHIP_ALLOCED;
}
if (!dir_in) {
/* copy to bounce buffer for a write */
memcpy (HDATA(cmd->device->host)->dma_bounce_buffer,
cmd->SCp.ptr, cmd->SCp.this_residual);
}
}
/* setup dma direction */
if (!dir_in)
cntr |= GVP11_DMAC_DIR_WRITE;
HDATA(cmd->device->host)->dma_dir = dir_in;
DMA(cmd->device->host)->CNTR = cntr;
/* setup DMA *physical* address */
DMA(cmd->device->host)->ACR = addr;
if (dir_in)
/* invalidate any cache */
cache_clear (addr, cmd->SCp.this_residual);
else
/* push any dirty cache */
cache_push (addr, cmd->SCp.this_residual);
if ((bank_mask = (~HDATA(cmd->device->host)->dma_xfer_mask >> 18) & 0x01c0))
DMA(cmd->device->host)->BANK = bank_mask & (addr >> 18);
/* start DMA */
DMA(cmd->device->host)->ST_DMA = 1;
/* return success */
return 0;
}
static void dma_stop(struct Scsi_Host *instance, struct scsi_cmnd *SCpnt,
int status)
{
/* stop DMA */
DMA(instance)->SP_DMA = 1;
/* remove write bit from CONTROL bits */
DMA(instance)->CNTR = GVP11_DMAC_INT_ENABLE;
/* copy from a bounce buffer, if necessary */
if (status && HDATA(instance)->dma_bounce_buffer) {
if (HDATA(instance)->dma_dir && SCpnt)
memcpy (SCpnt->SCp.ptr,
HDATA(instance)->dma_bounce_buffer,
SCpnt->SCp.this_residual);
if (HDATA(instance)->dma_buffer_pool == BUF_SCSI_ALLOCED)
kfree (HDATA(instance)->dma_bounce_buffer);
else
amiga_chip_free(HDATA(instance)->dma_bounce_buffer);
HDATA(instance)->dma_bounce_buffer = NULL;
HDATA(instance)->dma_bounce_len = 0;
}
}
#define CHECK_WD33C93
int __init gvp11_detect(struct scsi_host_template *tpnt)
{
static unsigned char called = 0;
struct Scsi_Host *instance;
unsigned long address;
unsigned int epc;
struct zorro_dev *z = NULL;
unsigned int default_dma_xfer_mask;
wd33c93_regs regs;
int num_gvp11 = 0;
#ifdef CHECK_WD33C93
volatile unsigned char *sasr_3393, *scmd_3393;
unsigned char save_sasr;
unsigned char q, qq;
#endif
if (!MACH_IS_AMIGA || called)
return 0;
called = 1;
tpnt->proc_name = "GVP11";
tpnt->proc_info = &wd33c93_proc_info;
while ((z = zorro_find_device(ZORRO_WILDCARD, z))) {
/*
* This should (hopefully) be the correct way to identify
* all the different GVP SCSI controllers (except for the
* SERIES I though).
*/
if (z->id == ZORRO_PROD_GVP_COMBO_030_R3_SCSI ||
z->id == ZORRO_PROD_GVP_SERIES_II)
default_dma_xfer_mask = ~0x00ffffff;
else if (z->id == ZORRO_PROD_GVP_GFORCE_030_SCSI ||
z->id == ZORRO_PROD_GVP_A530_SCSI ||
z->id == ZORRO_PROD_GVP_COMBO_030_R4_SCSI)
default_dma_xfer_mask = ~0x01ffffff;
else if (z->id == ZORRO_PROD_GVP_A1291 ||
z->id == ZORRO_PROD_GVP_GFORCE_040_SCSI_1)
default_dma_xfer_mask = ~0x07ffffff;
else
continue;
/*
* Rumors state that some GVP ram boards use the same product
* code as the SCSI controllers. Therefore if the board-size
* is not 64KB we asume it is a ram board and bail out.
*/
if (z->resource.end-z->resource.start != 0xffff)
continue;
address = z->resource.start;
if (!request_mem_region(address, 256, "wd33c93"))
continue;
#ifdef CHECK_WD33C93
/*
* These darn GVP boards are a problem - it can be tough to tell
* whether or not they include a SCSI controller. This is the
* ultimate Yet-Another-GVP-Detection-Hack in that it actually
* probes for a WD33c93 chip: If we find one, it's extremely
* likely that this card supports SCSI, regardless of Product_
* Code, Board_Size, etc.
*/
/* Get pointers to the presumed register locations and save contents */
sasr_3393 = &(((gvp11_scsiregs *)(ZTWO_VADDR(address)))->SASR);
scmd_3393 = &(((gvp11_scsiregs *)(ZTWO_VADDR(address)))->SCMD);
save_sasr = *sasr_3393;
/* First test the AuxStatus Reg */
q = *sasr_3393; /* read it */
if (q & 0x08) /* bit 3 should always be clear */
goto release;
*sasr_3393 = WD_AUXILIARY_STATUS; /* setup indirect address */
if (*sasr_3393 == WD_AUXILIARY_STATUS) { /* shouldn't retain the write */
*sasr_3393 = save_sasr; /* Oops - restore this byte */
goto release;
}
if (*sasr_3393 != q) { /* should still read the same */
*sasr_3393 = save_sasr; /* Oops - restore this byte */
goto release;
}
if (*scmd_3393 != q) /* and so should the image at 0x1f */
goto release;
/* Ok, we probably have a wd33c93, but let's check a few other places
* for good measure. Make sure that this works for both 'A and 'B
* chip versions.
*/
*sasr_3393 = WD_SCSI_STATUS;
q = *scmd_3393;
*sasr_3393 = WD_SCSI_STATUS;
*scmd_3393 = ~q;
*sasr_3393 = WD_SCSI_STATUS;
qq = *scmd_3393;
*sasr_3393 = WD_SCSI_STATUS;
*scmd_3393 = q;
if (qq != q) /* should be read only */
goto release;
*sasr_3393 = 0x1e; /* this register is unimplemented */
q = *scmd_3393;
*sasr_3393 = 0x1e;
*scmd_3393 = ~q;
*sasr_3393 = 0x1e;
qq = *scmd_3393;
*sasr_3393 = 0x1e;
*scmd_3393 = q;
if (qq != q || qq != 0xff) /* should be read only, all 1's */
goto release;
*sasr_3393 = WD_TIMEOUT_PERIOD;
q = *scmd_3393;
*sasr_3393 = WD_TIMEOUT_PERIOD;
*scmd_3393 = ~q;
*sasr_3393 = WD_TIMEOUT_PERIOD;
qq = *scmd_3393;
*sasr_3393 = WD_TIMEOUT_PERIOD;
*scmd_3393 = q;
if (qq != (~q & 0xff)) /* should be read/write */
goto release;
#endif
instance = scsi_register (tpnt, sizeof (struct WD33C93_hostdata));
if(instance == NULL)
goto release;
instance->base = ZTWO_VADDR(address);
instance->irq = IRQ_AMIGA_PORTS;
instance->unique_id = z->slotaddr;
if (gvp11_xfer_mask)
HDATA(instance)->dma_xfer_mask = gvp11_xfer_mask;
else
HDATA(instance)->dma_xfer_mask = default_dma_xfer_mask;
DMA(instance)->secret2 = 1;
DMA(instance)->secret1 = 0;
DMA(instance)->secret3 = 15;
while (DMA(instance)->CNTR & GVP11_DMAC_BUSY) ;
DMA(instance)->CNTR = 0;
DMA(instance)->BANK = 0;
epc = *(unsigned short *)(ZTWO_VADDR(address) + 0x8000);
/*
* Check for 14MHz SCSI clock
*/
regs.SASR = &(DMA(instance)->SASR);
regs.SCMD = &(DMA(instance)->SCMD);
wd33c93_init(instance, regs, dma_setup, dma_stop,
(epc & GVP_SCSICLKMASK) ? WD33C93_FS_8_10
: WD33C93_FS_12_15);
request_irq(IRQ_AMIGA_PORTS, gvp11_intr, IRQF_SHARED, "GVP11 SCSI",
instance);
DMA(instance)->CNTR = GVP11_DMAC_INT_ENABLE;
num_gvp11++;
continue;
release:
release_mem_region(address, 256);
}
return num_gvp11;
}
static int gvp11_bus_reset(struct scsi_cmnd *cmd)
{
/* FIXME perform bus-specific reset */
/* FIXME 2: shouldn't we no-op this function (return
FAILED), and fall back to host reset function,
wd33c93_host_reset ? */
spin_lock_irq(cmd->device->host->host_lock);
wd33c93_host_reset(cmd);
spin_unlock_irq(cmd->device->host->host_lock);
return SUCCESS;
}
#define HOSTS_C
#include "gvp11.h"
static struct scsi_host_template driver_template = {
.proc_name = "GVP11",
.name = "GVP Series II SCSI",
.detect = gvp11_detect,
.release = gvp11_release,
.queuecommand = wd33c93_queuecommand,
.eh_abort_handler = wd33c93_abort,
.eh_bus_reset_handler = gvp11_bus_reset,
.eh_host_reset_handler = wd33c93_host_reset,
.can_queue = CAN_QUEUE,
.this_id = 7,
.sg_tablesize = SG_ALL,
.cmd_per_lun = CMD_PER_LUN,
.use_clustering = DISABLE_CLUSTERING
};
#include "scsi_module.c"
int gvp11_release(struct Scsi_Host *instance)
{
#ifdef MODULE
DMA(instance)->CNTR = 0;
release_mem_region(ZTWO_PADDR(instance->base), 256);
free_irq(IRQ_AMIGA_PORTS, instance);
wd33c93_release();
#endif
return 1;
}
MODULE_LICENSE("GPL");
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