aacraid: SCSI blk tag support

The method to allocate and free FIB's in the present code utilizes
spinlocks. Multiple IO's have to wait on the spinlock to acquire or free
fibs creating a performance bottleneck.

An alternative solution would be to use block layer tags to keep track
of the fibs allocated and freed. To this end aac_fib_alloc_tag was
created to utilize the blk layer tags to plug into the Fib pool.These
functions are used exclusively in the IO path. 8 fibs are reserved for
the use of AIF management software and utilize the previous spinlock
based implementations.

Signed-off-by: Raghava Aditya Renukunta <RaghavaAditya.Renukunta@pmcs.com>
Reviewed-by: Shane Seymour <shane.seymour@hpe.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

1 files changed, 12 insertions, 15 deletions

diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
index e4c243748a97..7dfd0fa27255 100644
--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -323,7 +323,6 @@ static inline int aac_valid_context(struct scsi_cmnd *scsicmd,
 	if (unlikely(!scsicmd || !scsicmd->scsi_done)) {
 		dprintk((KERN_WARNING "aac_valid_context: scsi command corrupt\n"));
 		aac_fib_complete(fibptr);
-		aac_fib_free(fibptr);
 		return 0;
 	}
 	scsicmd->SCp.phase = AAC_OWNER_MIDLEVEL;
@@ -331,7 +330,6 @@ static inline int aac_valid_context(struct scsi_cmnd *scsicmd,
 	if (unlikely(!device || !scsi_device_online(device))) {
 		dprintk((KERN_WARNING "aac_valid_context: scsi device corrupt\n"));
 		aac_fib_complete(fibptr);
-		aac_fib_free(fibptr);
 		return 0;
 	}
 	return 1;
@@ -541,7 +539,6 @@ static void get_container_name_callback(void *context, struct fib * fibptr)
 	scsicmd->result = DID_OK << 16 | COMMAND_COMPLETE << 8 | SAM_STAT_GOOD;
 
 	aac_fib_complete(fibptr);
-	aac_fib_free(fibptr);
 	scsicmd->scsi_done(scsicmd);
 }
 
@@ -557,7 +554,8 @@ static int aac_get_container_name(struct scsi_cmnd * scsicmd)
 
 	dev = (struct aac_dev *)scsicmd->device->host->hostdata;
 
-	if (!(cmd_fibcontext = aac_fib_alloc(dev)))
+	cmd_fibcontext = aac_fib_alloc_tag(dev, scsicmd);
+	if (!cmd_fibcontext)
 		return -ENOMEM;
 
 	aac_fib_init(cmd_fibcontext);
@@ -586,7 +584,6 @@ static int aac_get_container_name(struct scsi_cmnd * scsicmd)
 
 	printk(KERN_WARNING "aac_get_container_name: aac_fib_send failed with status: %d.\n", status);
 	aac_fib_complete(cmd_fibcontext);
-	aac_fib_free(cmd_fibcontext);
 	return -1;
 }
 
@@ -1024,7 +1021,6 @@ static void get_container_serial_callback(void *context, struct fib * fibptr)
 	scsicmd->result = DID_OK << 16 | COMMAND_COMPLETE << 8 | SAM_STAT_GOOD;
 
 	aac_fib_complete(fibptr);
-	aac_fib_free(fibptr);
 	scsicmd->scsi_done(scsicmd);
 }
 
@@ -1040,7 +1036,8 @@ static int aac_get_container_serial(struct scsi_cmnd * scsicmd)
 
 	dev = (struct aac_dev *)scsicmd->device->host->hostdata;
 
-	if (!(cmd_fibcontext = aac_fib_alloc(dev)))
+	cmd_fibcontext = aac_fib_alloc_tag(dev, scsicmd);
+	if (!cmd_fibcontext)
 		return -ENOMEM;
 
 	aac_fib_init(cmd_fibcontext);
@@ -1068,7 +1065,6 @@ static int aac_get_container_serial(struct scsi_cmnd * scsicmd)
 
 	printk(KERN_WARNING "aac_get_container_serial: aac_fib_send failed with status: %d.\n", status);
 	aac_fib_complete(cmd_fibcontext);
-	aac_fib_free(cmd_fibcontext);
 	return -1;
 }
 
@@ -1869,7 +1865,6 @@ static void io_callback(void *context, struct fib * fibptr)
 		break;
 	}
 	aac_fib_complete(fibptr);
-	aac_fib_free(fibptr);
 
 	scsicmd->scsi_done(scsicmd);
 }
@@ -1954,7 +1949,8 @@ static int aac_read(struct scsi_cmnd * scsicmd)
 	/*
 	 *	Alocate and initialize a Fib
 	 */
-	if (!(cmd_fibcontext = aac_fib_alloc(dev))) {
+	cmd_fibcontext = aac_fib_alloc_tag(dev, scsicmd);
+	if (!cmd_fibcontext) {
 		printk(KERN_WARNING "aac_read: fib allocation failed\n");
 		return -1;
 	}
@@ -2051,7 +2047,8 @@ static int aac_write(struct scsi_cmnd * scsicmd)
 	/*
 	 *	Allocate and initialize a Fib then setup a BlockWrite command
 	 */
-	if (!(cmd_fibcontext = aac_fib_alloc(dev))) {
+	cmd_fibcontext = aac_fib_alloc_tag(dev, scsicmd);
+	if (!cmd_fibcontext) {
 		/* FIB temporarily unavailable,not catastrophic failure */
 
 		/* scsicmd->result = DID_ERROR << 16;
@@ -2285,7 +2282,7 @@ static int aac_start_stop(struct scsi_cmnd *scsicmd)
 	/*
 	 *	Allocate and initialize a Fib
 	 */
-	cmd_fibcontext = aac_fib_alloc(aac);
+	cmd_fibcontext = aac_fib_alloc_tag(aac, scsicmd);
 	if (!cmd_fibcontext)
 		return SCSI_MLQUEUE_HOST_BUSY;
 
@@ -3157,7 +3154,6 @@ static void aac_srb_callback(void *context, struct fib * fibptr)
 	scsicmd->result |= le32_to_cpu(srbreply->scsi_status);
 
 	aac_fib_complete(fibptr);
-	aac_fib_free(fibptr);
 	scsicmd->scsi_done(scsicmd);
 }
 
@@ -3187,9 +3183,10 @@ static int aac_send_srb_fib(struct scsi_cmnd* scsicmd)
 	/*
 	 *	Allocate and initialize a Fib then setup a BlockWrite command
 	 */
-	if (!(cmd_fibcontext = aac_fib_alloc(dev))) {
+	cmd_fibcontext = aac_fib_alloc_tag(dev, scsicmd);
+	if (!cmd_fibcontext)
 		return -1;
-	}
+
 	status = aac_adapter_scsi(cmd_fibcontext, scsicmd);
 
 	/*