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.
Also make the tag management functions static, where possible.
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
drivers/scsi/mvsas/mv_defs.h | 1 +
drivers/scsi/mvsas/mv_init.c | 9 +++++----
drivers/scsi/mvsas/mv_sas.c | 38 ++++++++++++++++++++++++------------
drivers/scsi/mvsas/mv_sas.h | 7 +------
4 files changed, 32 insertions(+), 23 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..cfe84473a515 100644
--- a/drivers/scsi/mvsas/mv_init.c
+++ b/drivers/scsi/mvsas/mv_init.c
@@ -142,7 +142,7 @@ static void mvs_free(struct mvs_info *mvi)
scsi_host_put(mvi->shost);
list_for_each_entry(mwq, &mvi->wq_list, entry)
cancel_delayed_work(&mwq->work_q);
- kfree(mvi->tags);
+ kfree(mvi->rsvd_tags);
kfree(mvi);
}
@@ -284,7 +284,6 @@ 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;
return 0;
err_out:
@@ -367,8 +366,8 @@ 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);
- if (!mvi->tags)
+ mvi->rsvd_tags = bitmap_zalloc(MVS_RSVD_SLOTS, GFP_KERNEL);
+ if (!mvi->rsvd_tags)
goto err_out;
if (MVS_CHIP_DISP->chip_ioremap(mvi))
@@ -469,6 +468,8 @@ static void mvs_post_sas_ha_init(struct Scsi_Host *shost,
else
can_queue = MVS_CHIP_SLOT_SZ;
+ can_queue -= MVS_RSVD_SLOTS;
+
shost->sg_tablesize = min_t(u16, SG_ALL, MVS_MAX_SG);
shost->can_queue = can_queue;
mvi->shost->cmd_per_lun = MVS_QUEUE_SIZE;
diff --git a/drivers/scsi/mvsas/mv_sas.c b/drivers/scsi/mvsas/mv_sas.c
index 0810e6c930e1..00b3a2781d21 100644
--- a/drivers/scsi/mvsas/mv_sas.c
+++ b/drivers/scsi/mvsas/mv_sas.c
@@ -20,33 +20,39 @@ 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;
+ void *bitmap = mvi->rsvd_tags;
clear_bit(tag, bitmap);
}
-void mvs_tag_free(struct mvs_info *mvi, u32 tag)
+static 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);
}
-void mvs_tag_set(struct mvs_info *mvi, unsigned int tag)
+static void mvs_tag_set(struct mvs_info *mvi, unsigned int tag)
{
- void *bitmap = mvi->tags;
+ void *bitmap = mvi->rsvd_tags;
set_bit(tag, bitmap);
}
-inline int mvs_tag_alloc(struct mvs_info *mvi, u32 *tag_out)
+static int mvs_tag_alloc(struct mvs_info *mvi, u32 *tag_out)
{
unsigned int index, tag;
- void *bitmap = mvi->tags;
+ void *bitmap = mvi->rsvd_tags;
- index = find_first_zero_bit(bitmap, mvi->tags_num);
+ index = find_first_zero_bit(bitmap, MVS_RSVD_SLOTS);
tag = index;
- if (tag >= mvi->tags_num)
+ if (tag >= MVS_RSVD_SLOTS)
return -SAS_QUEUE_FULL;
mvs_tag_set(mvi, tag);
+ tag += mvi->shost->can_queue;
*tag_out = tag;
return 0;
}
