[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 <martin.petersen@oracle.com>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 5276e73..ee6be59 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -197,11 +197,43 @@
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
* @gfp_mask: allocation mask
@@ -214,7 +246,7 @@
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 @@
/*
* 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;