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[SCSI] ips: Fix up for correct scatter/gather processing 

Added kmap_atomic/kunmap_atomic. Added protection of KM_IRQ0 slot with
local_irq_save(), local_irq_restore(), and comments.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
This commit is contained in:
Jack Hammer 2005-10-25 14:13:03 -04:00 committed by James Bottomley
parent eb66fff7d9
commit a3632fa3ec
1 changed files with 36 additions and 13 deletions
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49
drivers/scsi/ips.c
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@ -219,15 +219,12 @@ module_param(ips, charp, 0);
#if LINUX_VERSION_CODE <= KERNEL_VERSION(2,5,0)
#include <linux/blk.h>
#include "sd.h"
#define IPS_SG_ADDRESS(sg) ((sg)->address)
#define IPS_LOCK_SAVE(lock,flags) spin_lock_irqsave(&io_request_lock,flags)
#define IPS_UNLOCK_RESTORE(lock,flags) spin_unlock_irqrestore(&io_request_lock,flags)
#ifndef __devexit_p
#define __devexit_p(x) x
#endif
#else
#define IPS_SG_ADDRESS(sg) (page_address((sg)->page) ? \
page_address((sg)->page)+(sg)->offset : NULL)
#define IPS_LOCK_SAVE(lock,flags) do{spin_lock(lock);(void)flags;}while(0)
#define IPS_UNLOCK_RESTORE(lock,flags) do{spin_unlock(lock);(void)flags;}while(0)
#endif
@ -1605,6 +1602,8 @@ ips_proc_info(struct Scsi_Host *host, char *buffer, char **start, off_t offset,
static int
ips_is_passthru(Scsi_Cmnd * SC)
{
unsigned long flags;
METHOD_TRACE("ips_is_passthru", 1);
if (!SC)
@ -1622,10 +1621,20 @@ ips_is_passthru(Scsi_Cmnd * SC)
return 1;
else if (SC->use_sg) {
struct scatterlist *sg = SC->request_buffer;
char *buffer = IPS_SG_ADDRESS(sg);
char *buffer;
/* kmap_atomic() ensures addressability of the user buffer.*/
/* local_irq_save() protects the KM_IRQ0 address slot. */
local_irq_save(flags);
buffer = kmap_atomic(sg->page, KM_IRQ0) + sg->offset;
if (buffer && buffer[0] == 'C' && buffer[1] == 'O' &&
buffer[2] == 'P' && buffer[3] == 'P')
buffer[2] == 'P' && buffer[3] == 'P') {
kunmap_atomic(buffer - sg->offset, KM_IRQ0);
local_irq_restore(flags);
return 1;
}
kunmap_atomic(buffer - sg->offset, KM_IRQ0);
local_irq_restore(flags);
}
}
return 0;
@ -3656,14 +3665,21 @@ ips_scmd_buf_write(Scsi_Cmnd * scmd, void *data, unsigned
int i;
unsigned int min_cnt, xfer_cnt;
char *cdata = (char *) data;
unsigned char *buffer;
unsigned long flags;
struct scatterlist *sg = scmd->request_buffer;
for (i = 0, xfer_cnt = 0;
(i < scmd->use_sg) && (xfer_cnt < count); i++) {
if (!IPS_SG_ADDRESS(&sg[i]))
return;
min_cnt = min(count - xfer_cnt, sg[i].length);
memcpy(IPS_SG_ADDRESS(&sg[i]), &cdata[xfer_cnt],
min_cnt);
/* kmap_atomic() ensures addressability of the data buffer.*/
/* local_irq_save() protects the KM_IRQ0 address slot. */
local_irq_save(flags);
buffer = kmap_atomic(sg[i].page, KM_IRQ0) + sg[i].offset;
memcpy(buffer, &cdata[xfer_cnt], min_cnt);
kunmap_atomic(buffer - sg[i].offset, KM_IRQ0);
local_irq_restore(flags);
xfer_cnt += min_cnt;
}
@ -3688,14 +3704,21 @@ ips_scmd_buf_read(Scsi_Cmnd * scmd, void *data, unsigned
int i;
unsigned int min_cnt, xfer_cnt;
char *cdata = (char *) data;
unsigned char *buffer;
unsigned long flags;
struct scatterlist *sg = scmd->request_buffer;
for (i = 0, xfer_cnt = 0;
(i < scmd->use_sg) && (xfer_cnt < count); i++) {
if (!IPS_SG_ADDRESS(&sg[i]))
return;
min_cnt = min(count - xfer_cnt, sg[i].length);
memcpy(&cdata[xfer_cnt], IPS_SG_ADDRESS(&sg[i]),
min_cnt);
/* kmap_atomic() ensures addressability of the data buffer.*/
/* local_irq_save() protects the KM_IRQ0 address slot. */
local_irq_save(flags);
buffer = kmap_atomic(sg[i].page, KM_IRQ0) + sg[i].offset;
memcpy(&cdata[xfer_cnt], buffer, min_cnt);
kunmap_atomic(buffer - sg[i].offset, KM_IRQ0);
local_irq_restore(flags);
xfer_cnt += min_cnt;
}