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

[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
......@@ -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;
......
......@@ -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:
......
......@@ -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
......
......@@ -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 */
......@@ -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"
......
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