Commit a3632fa3 authored by Jack Hammer's avatar Jack Hammer Committed by James Bottomley
Browse files

[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: default avatarJames Bottomley <James.Bottomley@SteelEye.com>
parent eb66fff7

drivers/scsi/ips.c

+36 −13
Original line number Diff line number Diff line
@@ -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)
@@ -1622,11 +1621,21 @@ 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;

		}