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.
- Handle protection scsi_data_buffer in command allocation.
- Preallocate protection scsi_data_buffer in command freelist if host
is DIX (integrity DMA) capable.
- Accessor function for checking whether a device has protection
enabled.
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
---
7 files changed, 97 insertions(+), 11 deletions(-)
drivers/scsi/scsi.c | 47 ++++++++++++++++++++++++++++++++++++++-----
drivers/scsi/scsi_error.c | 2 -
drivers/scsi/scsi_lib.c | 27 ++++++++++++++++++++++--
drivers/scsi/scsi_priv.h | 1
drivers/scsi/scsi_tgt_lib.c | 2 -
include/scsi/scsi_cmnd.h | 24 ++++++++++++++++++++-
include/scsi/scsi_device.h | 5 ++++
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -199,24 +199,60 @@ scsi_pool_free_command(struct scsi_host_
{
kmem_cache_free(pool->sense_slab, cmd->sense_buffer);
kmem_cache_free(pool->cmd_slab, cmd);
+
+ if (cmd->prot_sdb)
+ kmem_cache_free(scsi_sdb_cache, cmd->prot_sdb);
+}
+
+/**
+ * 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
* @gfp_mask: allocation mask
+ * @protection: allocate protection sdb
*
* Description: allocate a struct scsi_cmd from host's slab, recycling from the
* host's free_list if necessary.
*/
-struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask)
+struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *shost, gfp_t gfp_mask, int protection)
{
struct scsi_cmnd *cmd;
unsigned char *buf;
cmd = scsi_pool_alloc_command(shost->cmd_pool, gfp_mask);
- if (unlikely(!cmd)) {
+ if (protection)
+ cmd->prot_sdb = kmem_cache_zalloc(scsi_sdb_cache, gfp_mask);
+
+ if (unlikely(!cmd) || unlikely(protection && cmd->prot_sdb == NULL)) {
unsigned long flags;
spin_lock_irqsave(&shost->free_list_lock, flags);
@@ -242,10 +278,11 @@ EXPORT_SYMBOL_GPL(__scsi_get_command);
* scsi_get_command - Allocate and setup a scsi command block
* @dev: parent scsi device
* @gfp_mask: allocator flags
+ * @protection: allocate protection sdb
*
* Returns: The allocated scsi command structure.
*/
-struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask)
+struct scsi_cmnd *scsi_get_command(struct scsi_device *dev, gfp_t gfp_mask, int protection)
{
struct scsi_cmnd *cmd;
@@ -253,7 +290,7 @@ struct scsi_cmnd *scsi_get_command(struc
if (!get_device(&dev->sdev_gendev))
return NULL;
- cmd = __scsi_get_command(dev->host, gfp_mask);
+ cmd = __scsi_get_command(dev->host, gfp_mask, protection);
if (likely(cmd != NULL)) {
unsigned long flags;
@@ -457,7 +494,7 @@ int scsi_setup_command_freelist(struct S
/*
* 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_error.c b/drivers/scsi/scsi_error.c
--- a/drivers/scsi/scsi_error.c
+++ b/drivers/scsi/scsi_error.c
@@ -1769,7 +1769,7 @@ int
int
scsi_reset_provider(struct scsi_device *dev, int flag)
{
- struct scsi_cmnd *scmd = scsi_get_command(dev, GFP_KERNEL);
+ struct scsi_cmnd *scmd = scsi_get_command(dev, GFP_KERNEL, 0);
struct Scsi_Host *shost = dev->host;
struct request req;
unsigned long flags;
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -65,7 +65,7 @@ static struct scsi_host_sg_pool scsi_sg_
};
#undef SP
-static struct kmem_cache *scsi_sdb_cache;
+struct kmem_cache *scsi_sdb_cache;
static void scsi_run_queue(struct request_queue *q);
@@ -778,6 +778,9 @@ void scsi_release_buffers(struct scsi_cm
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);
@@ -1063,6 +1066,26 @@ int scsi_init_io(struct scsi_cmnd *cmd,
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:
@@ -1082,7 +1105,7 @@ static struct scsi_cmnd *scsi_get_cmd_fr
struct scsi_cmnd *cmd;
if (!req->special) {
- cmd = scsi_get_command(sdev, GFP_ATOMIC);
+ cmd = scsi_get_command(sdev, GFP_ATOMIC, blk_integrity_rq(req));
if (unlikely(!cmd))
return NULL;
req->special = cmd;
diff --git a/drivers/scsi/scsi_priv.h b/drivers/scsi/scsi_priv.h
--- a/drivers/scsi/scsi_priv.h
+++ b/drivers/scsi/scsi_priv.h
@@ -77,6 +77,7 @@ struct request_queue;
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/drivers/scsi/scsi_tgt_lib.c b/drivers/scsi/scsi_tgt_lib.c
--- a/drivers/scsi/scsi_tgt_lib.c
+++ b/drivers/scsi/scsi_tgt_lib.c
@@ -99,7 +99,7 @@ struct scsi_cmnd *scsi_host_get_command(
if (!rq)
goto free_tcmd;
- cmd = __scsi_get_command(shost, gfp_mask);
+ cmd = __scsi_get_command(shost, gfp_mask, 0);
if (!cmd)
goto release_rq;
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
--- 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 */
@@ -131,8 +133,8 @@ struct scsi_cmnd {
unsigned char tag; /* SCSI-II queued command tag */
};
-extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t);
-extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t);
+extern struct scsi_cmnd *scsi_get_command(struct scsi_device *, gfp_t, int);
+extern struct scsi_cmnd *__scsi_get_command(struct Scsi_Host *, gfp_t, int);
extern void scsi_put_command(struct scsi_cmnd *);
extern void __scsi_put_command(struct Scsi_Host *, struct scsi_cmnd *,
struct device *);
@@ -237,4 +239,22 @@ enum scsi_prot_operations {
SCSI_PROT_WRITE_CONVERT,
};
+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
--- a/include/scsi/scsi_device.h
+++ b/include/scsi/scsi_device.h
@@ -393,6 +393,11 @@ static inline int scsi_device_enclosure(
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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