[PATCH V4 1/9] aacraid: SCSI blk tag support

Raghava Aditya Renukunta
2016-01-29T22:35:39Z

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.

Changes in V2:
Removed aac_fib_free_tag since it was a stub function
Moved population of fib fields that are constant to aac_fib_setup

Changes in V3:
None

Changes in V4:
None

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>
---
drivers/scsi/aacraid/aachba.c | 27 ++++++++++++---------------
drivers/scsi/aacraid/aacraid.h | 1 +
drivers/scsi/aacraid/commsup.c | 32 +++++++++++++++++++++++++++++---
drivers/scsi/aacraid/dpcsup.c | 2 --
drivers/scsi/aacraid/linit.c | 2 ++
5 files changed, 44 insertions(+), 20 deletions(-)

diff --git a/drivers/scsi/aacraid/aachba.c b/drivers/scsi/aacraid/aachba.c
index e4c2437..7dfd0fa 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);

/*
diff --git a/drivers/scsi/aacraid/aacraid.h b/drivers/scsi/aacraid/aacraid.h
index 074878b..f51f0a0 100644
--- a/drivers/scsi/aacraid/aacraid.h
+++ b/drivers/scsi/aacraid/aacraid.h
@@ -2114,6 +2114,7 @@ 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);
diff --git a/drivers/scsi/aacraid/commsup.c b/drivers/scsi/aacraid/commsup.c
index a1f90fe..46a2a2f 100644
--- a/drivers/scsi/aacraid/commsup.c
+++ b/drivers/scsi/aacraid/commsup.c
@@ -137,6 +137,7 @@ int aac_fib_setup(struct aac_dev * dev)
i++, fibptr++)
{
fibptr->flags = 0;
+ fibptr->size = sizeof(struct fib);
fibptr->dev = dev;
fibptr->hw_fib_va = hw_fib;
fibptr->data = (void *) fibptr->hw_fib_va->data;
@@ -156,13 +157,38 @@ 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;
}

/**
+ * aac_fib_alloc_tag-allocate a fib using tags
+ * @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];
+ /*
+ * Null out fields that depend on being zero at the start of
+ * each I/O
+ */
+ fibptr->hw_fib_va->header.XferState = 0;
+ fibptr->type = FSAFS_NTC_FIB_CONTEXT;
+ fibptr->callback_data = NULL;
+ fibptr->callback = NULL;
+
+ return fibptr;
+}
+
+/**
* aac_fib_alloc - allocate a fib
* @dev: Adapter to allocate the fib for
*
diff --git a/drivers/scsi/aacraid/dpcsup.c b/drivers/scsi/aacraid/dpcsup.c
index da9d993..d677b52 100644
--- a/drivers/scsi/aacraid/dpcsup.c
+++ b/drivers/scsi/aacraid/dpcsup.c
@@ -394,7 +394,6 @@ 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);
}
} else {
unsigned long flagv;
@@ -416,7 +415,6 @@ 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);
}

}
diff --git a/drivers/scsi/aacraid/linit.c b/drivers/scsi/aacraid/linit.c
index 76eaa38..129a515 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