[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>
diff --git a/drivers/scsi/ips.c b/drivers/scsi/ips.c
index eeae7cc..0a252e7 100644
--- a/drivers/scsi/ips.c
+++ b/drivers/scsi/ips.c
@@ -219,15 +219,12 @@
#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 @@
static int
ips_is_passthru(Scsi_Cmnd * SC)
{
+ unsigned long flags;
+
METHOD_TRACE("ips_is_passthru", 1);
if (!SC)
@@ -1622,10 +1621,20 @@
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 @@
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 @@
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;
}