[PATCH 01/10] aacraid: SCSI blk tag support

[Raghava Aditya Renukunta <RaghavaAditya.Renukunta@pmcs.com>]

From: Raghava Aditya Renukunta <raghavaaditya.renukunta@pmcs.com>

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 2 functions
aac_fib_alloc_tag and aac_fib_free_tag were created which 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>
---
 drivers/scsi/aacraid/aachba.c  | 35 +++++++++++++++++-------------
 drivers/scsi/aacraid/aacraid.h |  2 ++
 drivers/scsi/aacraid/commsup.c | 49 +++++++++++++++++++++++++++++++++++++++---
 drivers/scsi/aacraid/dpcsup.c  |  4 ++--
 drivers/scsi/aacraid/linit.c   |  2 ++
 5 files changed, 72 insertions(+), 20 deletions(-)

diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
index e4c2437..06cbab8 100644
--- a/drivers/scsi/aacraid/aachba.c
+++ b/drivers/scsi/aacraid/aachba.c
@@ -323,7 +323,7 @@ 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);
+		aac_fib_free_tag(fibptr);
 		return 0;
 	}
 	scsicmd->SCp.phase = AAC_OWNER_MIDLEVEL;
@@ -331,7 +331,7 @@ 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);
+		aac_fib_free_tag(fibptr);
 		return 0;
 	}
 	return 1;
@@ -541,7 +541,7 @@ 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);
+	aac_fib_free_tag(fibptr);
 	scsicmd->scsi_done(scsicmd);
 }
 
@@ -557,7 +557,8 @@ 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 +587,7 @@ 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);
+	aac_fib_free_tag(cmd_fibcontext);
 	return -1;
 }
 
@@ -1024,7 +1025,7 @@ 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);
+	aac_fib_free_tag(fibptr);
 	scsicmd->scsi_done(scsicmd);
 }
 
@@ -1040,7 +1041,8 @@ 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 +1070,7 @@ 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);
+	aac_fib_free_tag(cmd_fibcontext);
 	return -1;
 }
 
@@ -1869,7 +1871,7 @@ static void io_callback(void *context, struct fib * fibptr)
 		break;
 	}
 	aac_fib_complete(fibptr);
-	aac_fib_free(fibptr);
+	aac_fib_free_tag(fibptr);
 
 	scsicmd->scsi_done(scsicmd);
 }
@@ -1954,7 +1956,8 @@ 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 +2054,8 @@ 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 +2289,7 @@ 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 +3161,7 @@ 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);
+	aac_fib_free_tag(fibptr);
 	scsicmd->scsi_done(scsicmd);
 }
 
@@ -3187,9 +3191,10 @@ 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);
 
 	/*
diff --git a/drivers/scsi/aacraid/aacraid.h b/drivers/scsi/aacraid/aacraid.h
index 074878b..da227e8 100644
--- a/drivers/scsi/aacraid/aacraid.h
+++ b/drivers/scsi/aacraid/aacraid.h
@@ -2114,9 +2114,11 @@ int aac_acquire_irq(struct aac_dev *dev);
 void aac_free_irq(struct aac_dev *dev);
 const char *aac_driverinfo(struct Scsi_Host *);
 struct fib *aac_fib_alloc(struct aac_dev *dev);
+struct fib *aac_fib_alloc_tag(struct aac_dev *dev, struct scsi_cmnd *scmd);
 int aac_fib_setup(struct aac_dev *dev);
 void aac_fib_map_free(struct aac_dev *dev);
 void aac_fib_free(struct fib * context);
+void aac_fib_free_tag(struct fib *context);
 void aac_fib_init(struct fib * context);
 void aac_printf(struct aac_dev *dev, u32 val);
 int aac_fib_send(u16 command, struct fib * context, unsigned long size, int priority, int wait, int reply, fib_callback callback, void *ctxt);
diff --git a/drivers/scsi/aacraid/commsup.c b/drivers/scsi/aacraid/commsup.c
index a1f90fe..b5b653c 100644
--- a/drivers/scsi/aacraid/commsup.c
+++ b/drivers/scsi/aacraid/commsup.c
@@ -156,9 +156,9 @@ int aac_fib_setup(struct aac_dev * dev)
 	 */
 	dev->fibs[dev->scsi_host_ptr->can_queue + AAC_NUM_MGT_FIB - 1].next = NULL;
 	/*
-	 *	Enable this to debug out of queue space
-	 */
-	dev->free_fib = &dev->fibs[0];
+	*	Set 8 fibs aside for management tools
+	*/
+	dev->free_fib = &dev->fibs[dev->scsi_host_ptr->can_queue];
 	return 0;
 }
 
@@ -166,6 +166,49 @@ int aac_fib_setup(struct aac_dev * dev)
  *	aac_fib_alloc	-	allocate a fib
  *	@dev: Adapter to allocate the fib for
  *
+ *	Allocate a fib from the adapter fib pool using tags
+ *	from the blk layer.
+ */
+
+struct fib *aac_fib_alloc_tag(struct aac_dev *dev, struct scsi_cmnd *scmd)
+{
+	struct fib *fibptr;
+
+	fibptr = &dev->fibs[scmd->request->tag];
+	/*
+	 *	Set the proper node type code and node byte size
+	 */
+	fibptr->type = FSAFS_NTC_FIB_CONTEXT;
+	fibptr->size = sizeof(struct fib);
+	/*
+	 *	Null out fields that depend on being zero at the start of
+	 *	each I/O
+	 */
+	fibptr->hw_fib_va->header.XferState = 0;
+	fibptr->flags = 0;
+	fibptr->callback = NULL;
+	fibptr->callback_data = NULL;
+
+	return fibptr;
+}
+
+/**
+ *	aac_fib_free_tag	free a fib
+ *	@fibptr: fib to free up
+ *
+ *	Placeholder to free tag allocated fibs
+ *	Does not do anything
+ */
+
+void aac_fib_free_tag(struct fib *fibptr)
+{
+	(void)fibptr;
+}
+
+/**
+ *	aac_fib_alloc	-	allocate a fib
+ *	@dev: Adapter to allocate the fib for
+ *
  *	Allocate a fib from the adapter fib pool. If the pool is empty we
  *	return NULL.
  */
diff --git a/drivers/scsi/aacraid/dpcsup.c b/drivers/scsi/aacraid/dpcsup.c
index da9d993..c0127f0 100644
--- a/drivers/scsi/aacraid/dpcsup.c
+++ b/drivers/scsi/aacraid/dpcsup.c
@@ -394,7 +394,7 @@ unsigned int aac_intr_normal(struct aac_dev *dev, u32 index,
 				fib->callback(fib->callback_data, fib);
 			} else {
 				aac_fib_complete(fib);
-				aac_fib_free(fib);
+				aac_fib_free_tag(fib);
 			}
 		} else {
 			unsigned long flagv;
@@ -416,7 +416,7 @@ unsigned int aac_intr_normal(struct aac_dev *dev, u32 index,
 				fib->done = 0;
 				spin_unlock_irqrestore(&fib->event_lock, flagv);
 				aac_fib_complete(fib);
-				aac_fib_free(fib);
+				aac_fib_free_tag(fib);
 			}
 
 		}
diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index 3b6e5c6..fa0fc44 100644
--- a/drivers/scsi/aacraid/linit.c
+++ b/drivers/scsi/aacraid/linit.c
@@ -454,6 +454,8 @@ static int aac_slave_configure(struct scsi_device *sdev)
 	} else
 		scsi_change_queue_depth(sdev, 1);
 
+		sdev->tagged_supported = 1;
+
 	return 0;
 }
 
-- 
1.9.1