From 7027ad72a689797475973c6feb5f0b673382f779 Mon Sep 17 00:00:00 2001 From: "Martin K. Petersen" Date: Thu, 17 Jul 2008 17:08:48 -0400 Subject: [PATCH] [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: Martin K. Petersen Signed-off-by: James Bottomley --- drivers/scsi/scsi.c | 36 ++++++++++++++++++++++++++++++++++-- drivers/scsi/scsi_lib.c | 25 ++++++++++++++++++++++++- drivers/scsi/scsi_priv.h | 1 + include/scsi/scsi_cmnd.h | 20 ++++++++++++++++++++ include/scsi/scsi_device.h | 5 +++++ 5 files changed, 84 insertions(+), 3 deletions(-) diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c index 5276e73c58fc..ee6be596503d 100644 --- a/drivers/scsi/scsi.c +++ b/drivers/scsi/scsi.c @@ -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; diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c index fe77ccacf319..a47c05d7829a 100644 --- a/drivers/scsi/scsi_lib.c +++ b/drivers/scsi/scsi_lib.c @@ -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: diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h index b33e72516ef8..79f0f7511204 100644 --- a/drivers/scsi/scsi_priv.h +++ b/drivers/scsi/scsi_priv.h @@ -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 diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h index 402c1078d01c..f9f6e793575c 100644 --- a/include/scsi/scsi_cmnd.h +++ b/include/scsi/scsi_cmnd.h @@ -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 */ diff --git a/include/scsi/scsi_device.h b/include/scsi/scsi_device.h index 4deb9349eebf..9cecc409f0f8 100644 --- a/include/scsi/scsi_device.h +++ b/include/scsi/scsi_device.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" -- 2.20.1