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Commit 7027ad72 authored by Martin K. Petersen's avatar Martin K. Petersen Committed by James Bottomley
Browse files

[SCSI] Support devices with protection information 



Implement support for DMA of protection information for devices that
are data integrity capable.

 - Add support for mapping an extra scatter-gather list containing
   the protection information.

 - Allocate protection scsi_data_buffer if host is DIX (integrity DMA)
   capable.

 - Accessor function for checking whether a device has protection
   enabled.

Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: default avatarJames Bottomley <James.Bottomley@HansenPartnership.com>
parent db007fc5

drivers/scsi/scsi.c

+34 −2
Original line number Diff line number Diff line
@@ -197,10 +197,42 @@ static void 
scsi_pool_free_command(struct scsi_host_cmd_pool *pool,

			 struct scsi_cmnd *cmd)

{

	if (cmd->prot_sdb)

		kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);



	kmem_cache_free(pool->sense_slab, cmd->sense_buffer);

	kmem_cache_free(pool->cmd_slab, cmd);

}



/**

 * scsi_host_alloc_command - internal function to allocate command

 * @shost:	SCSI host whose pool to allocate from

 * @gfp_mask:	mask for the allocation

 *

 * Returns a fully allocated command with sense buffer and protection

 * data buffer (where applicable) or NULL on failure

 */

static struct scsi_cmnd *

scsi_host_alloc_command(struct Scsi_Host *shost, gfp_t gfp_mask)

{

	struct scsi_cmnd *cmd;



	cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask);

	if (!cmd)

		return NULL;



	if (scsi_host_get_prot(shost) >= SHOST_DIX_TYPE0_PROTECTION) {

		cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask);



		if (!cmd->prot_sdb) {

			scsi_pool_free_command(shost->cmd_pool, cmd);

			return NULL;

		}

	}



	return cmd;

}



/**

 * __scsi_get_command - Allocate a struct scsi_cmnd

 * @shost: host to transmit command
@@ -214,7 +246,7 @@ struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask) 
	struct scsi_cmnd *cmd;

	unsigned char *buf;



	cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask);

	cmd = scsi_host_alloc_command(shost, gfp_mask);



	if (unlikely(!cmd)) {

		unsigned long flags;
@@ -457,7 +489,7 @@ int scsi_setup_command_freelist(struct Scsi_Host *shost) 
	/*

	 * Get one backup command for this host.

	 */

	cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask);

	cmd = scsi_host_alloc_command(shost, gfp_mask);

	if (!cmd) {

		scsi_put_host_cmd_pool(gfp_mask);

		shost->cmd_pool = NULL;

drivers/scsi/scsi_lib.c

+24 −1
Original line number Diff line number Diff line
@@ -65,7 +65,7 @@ static struct scsi_host_sg_pool scsi_sg_pools[] = { 
};

#undef SP



static struct kmem_cache *scsi_sdb_cache;

struct kmem_cache *scsi_sdb_cache;



static void scsi_run_queue(struct request_queue *q);
@@ -787,6 +787,9 @@ void scsi_release_buffers(struct scsi_cmnd *cmd) 
		kmem_cache_free(scsi_sdb_cache, bidi_sdb);

		cmd->request->next_rq->special = NULL;

	}



	if (scsi_prot_sg_count(cmd))

		scsi_free_sgtable(cmd->prot_sdb);

}

EXPORT_SYMBOL(scsi_release_buffers);
@@ -1072,6 +1075,26 @@ int scsi_init_io(struct scsi_cmnd *cmd, gfp_t gfp_mask) 
			goto err_exit;

	}



	if (blk_integrity_rq(cmd->request)) {

		struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;

		int ivecs, count;



		BUG_ON(prot_sdb == NULL);

		ivecs = blk_rq_count_integrity_sg(cmd->request);



		if (scsi_alloc_sgtable(prot_sdb, ivecs, gfp_mask)) {

			error = BLKPREP_DEFER;

			goto err_exit;

		}



		count = blk_rq_map_integrity_sg(cmd->request,

						prot_sdb->table.sgl);

		BUG_ON(unlikely(count > ivecs));



		cmd->prot_sdb = prot_sdb;

		cmd->prot_sdb->table.nents = count;

	}



	return BLKPREP_OK ;



err_exit:

drivers/scsi/scsi_priv.h

+1 −0
Original line number Diff line number Diff line
@@ -77,6 +77,7 @@ extern void scsi_exit_queue(void); 
struct request_queue;

struct request;

extern int scsi_prep_fn(struct request_queue *, struct request *);

extern struct kmem_cache *scsi_sdb_cache;



/* scsi_proc.c */

#ifdef CONFIG_SCSI_PROC_FS

include/scsi/scsi_cmnd.h

+20 −0
Original line number Diff line number Diff line
@@ -90,6 +90,8 @@ struct scsi_cmnd { 


	/* These elements define the operation we ultimately want to perform */

	struct scsi_data_buffer sdb;

	struct scsi_data_buffer *prot_sdb;



	unsigned underflow;	/* Return error if less than

				   this amount is transferred */
@@ -274,4 +276,22 @@ static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd) 
	return scmd->request->sector;

}



static inline unsigned scsi_prot_sg_count(struct scsi_cmnd *cmd)

{

	return cmd->prot_sdb ? cmd->prot_sdb->table.nents : 0;

}



static inline struct scatterlist *scsi_prot_sglist(struct scsi_cmnd *cmd)

{

	return cmd->prot_sdb ? cmd->prot_sdb->table.sgl : NULL;

}



static inline struct scsi_data_buffer *scsi_prot(struct scsi_cmnd *cmd)

{

	return cmd->prot_sdb;

}



#define scsi_for_each_prot_sg(cmd, sg, nseg, __i)		\

	for_each_sg(scsi_prot_sglist(cmd), sg, nseg, __i)



#endif /* _SCSI_SCSI_CMND_H */

include/scsi/scsi_device.h

+5 −0
Original line number Diff line number Diff line
@@ -423,6 +423,11 @@ static inline int scsi_device_enclosure(struct scsi_device *sdev) 
	return sdev->inquiry[6] & (1<<6);

}



static inline int scsi_device_protection(struct scsi_device *sdev)

{

	return sdev->inquiry[5] & (1<<0);

}



#define MODULE_ALIAS_SCSI_DEVICE(type) \

	MODULE_ALIAS("scsi:t-" __stringify(type) "*")

#define SCSI_DEVICE_MODALIAS_FMT "scsi:t-0x%02x"