The request associated with a scsi command coming from the block layer
has a unique tag, so use that when possible for getting a slot.
Unfortunately we don't support reserved commands in the SCSI midlayer yet.
As such, SMP tasks - as an example - will not have a request associated, so
in the interim continue to manage those tags for that type of sas_task
internally.
We reserve an arbitrary 4 tags for these internal tags. Indeed, we already
decrement MVS_RSVD_SLOTS by 2 for the shost can_queue when flag
MVF_FLAG_SOC is set. This change was made in commit 20b09c2992fef
("[PATCH] [SCSI] mvsas: add support for 94xx; layout change; bug fixes"),
but what those 2 slots are used for is not obvious.
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
drivers/scsi/mvsas/mv_defs.h | 1 +
drivers/scsi/mvsas/mv_init.c | 4 ++--
drivers/scsi/mvsas/mv_sas.c | 22 +++++++++++++++++-----
drivers/scsi/mvsas/mv_sas.h | 1 -
4 files changed, 20 insertions(+), 8 deletions(-)
diff --git a/drivers/scsi/mvsas/mv_defs.h b/drivers/scsi/mvsas/mv_defs.h
index 7123a2efbf58..8ef174cd4d37 100644
--- a/drivers/scsi/mvsas/mv_defs.h
+++ b/drivers/scsi/mvsas/mv_defs.h
@@ -40,6 +40,7 @@ enum driver_configuration {
MVS_ATA_CMD_SZ = 96, /* SATA command table buffer size */
MVS_OAF_SZ = 64, /* Open address frame buffer size */
MVS_QUEUE_SIZE = 64, /* Support Queue depth */
+ MVS_RSVD_SLOTS = 4,
MVS_SOC_CAN_QUEUE = MVS_SOC_SLOTS - 2,
};
diff --git a/drivers/scsi/mvsas/mv_init.c b/drivers/scsi/mvsas/mv_init.c
index c85fb812ad43..d834ed9e8e4a 100644
--- a/drivers/scsi/mvsas/mv_init.c
+++ b/drivers/scsi/mvsas/mv_init.c
@@ -284,7 +284,7 @@ static int mvs_alloc(struct mvs_info *mvi, struct Scsi_Host *shost)
printk(KERN_DEBUG "failed to create dma pool %s.\n", pool_name);
goto err_out;
}
- mvi->tags_num = slot_nr;
+ mvi->tags_num = MVS_RSVD_SLOTS;
return 0;
err_out:
@@ -367,7 +367,7 @@ static struct mvs_info *mvs_pci_alloc(struct pci_dev *pdev,
mvi->sas = sha;
mvi->shost = shost;
- mvi->tags = kzalloc(MVS_CHIP_SLOT_SZ>>3, GFP_KERNEL);
+ mvi->tags = kzalloc(MVS_RSVD_SLOTS, GFP_KERNEL);
if (!mvi->tags)
goto err_out;
diff --git a/drivers/scsi/mvsas/mv_sas.c b/drivers/scsi/mvsas/mv_sas.c
index 0810e6c930e1..549d2ec89f60 100644
--- a/drivers/scsi/mvsas/mv_sas.c
+++ b/drivers/scsi/mvsas/mv_sas.c
@@ -20,7 +20,7 @@ static int mvs_find_tag(struct mvs_info *mvi, struct sas_task *task, u32 *tag)
return 0;
}
-void mvs_tag_clear(struct mvs_info *mvi, u32 tag)
+static void mvs_tag_clear(struct mvs_info *mvi, u32 tag)
{
void *bitmap = mvi->tags;
clear_bit(tag, bitmap);
@@ -28,6 +28,11 @@ void mvs_tag_clear(struct mvs_info *mvi, u32 tag)
void mvs_tag_free(struct mvs_info *mvi, u32 tag)
{
+ if (tag < mvi->shost->can_queue)
+ return;
+
+ tag -= mvi->shost->can_queue;
+
mvs_tag_clear(mvi, tag);
}
@@ -47,6 +52,7 @@ inline int mvs_tag_alloc(struct mvs_info *mvi, u32 *tag_out)
if (tag >= mvi->tags_num)
return -SAS_QUEUE_FULL;
mvs_tag_set(mvi, tag);
+ tag += mvi->shost->can_queue;
*tag_out = tag;
return 0;
}
@@ -696,6 +702,7 @@ static int mvs_task_prep(struct sas_task *task, struct mvs_info *mvi, int is_tmf
struct mvs_task_exec_info tei;
struct mvs_slot_info *slot;
u32 tag = 0xdeadbeef, n_elem = 0;
+ struct request *rq;
int rc = 0;
if (!dev->port) {
@@ -760,9 +767,14 @@ static int mvs_task_prep(struct sas_task *task, struct mvs_info *mvi, int is_tmf
n_elem = task->num_scatter;
}
- rc = mvs_tag_alloc(mvi, &tag);
- if (rc)
- goto err_out;
+ rq = sas_task_find_rq(task);
+ if (rq) {
+ tag = rq->tag;
+ } else {
+ rc = mvs_tag_alloc(mvi, &tag);
+ if (rc)
+ goto err_out;
+ }
slot = &mvi->slot_info[tag];
@@ -857,7 +869,7 @@ int mvs_queue_command(struct sas_task *task, gfp_t gfp_flags)
static void mvs_slot_free(struct mvs_info *mvi, u32 rx_desc)
{
u32 slot_idx = rx_desc & RXQ_SLOT_MASK;
- mvs_tag_clear(mvi, slot_idx);
+ mvs_tag_free(mvi, slot_idx);
}
static void mvs_slot_task_free(struct mvs_info *mvi, struct sas_task *task,
diff --git a/drivers/scsi/mvsas/mv_sas.h b/drivers/scsi/mvsas/mv_sas.h
index fe57665bdb50..e6c70786ded9 100644
--- a/drivers/scsi/mvsas/mv_sas.h
+++ b/drivers/scsi/mvsas/mv_sas.h
@@ -424,7 +424,6 @@ struct mvs_task_exec_info {
/******************** function prototype *********************/
void mvs_get_sas_addr(void *buf, u32 buflen);
-void mvs_tag_clear(struct mvs_info *mvi, u32 tag);
void mvs_tag_free(struct mvs_info *mvi, u32 tag);
void mvs_tag_set(struct mvs_info *mvi, unsigned int tag);
int mvs_tag_alloc(struct mvs_info *mvi, u32 *tag_out);
--
2.35.3
