From: "Matthew R. Ochs" <mrochs@xxxxxxxxxxxxxxxxxx>
AFUs can only process a single AFU command at a time. This is enforced
with a global mutex situated within the AFU send routine. As this mutex
has a global scope, it has the potential to unnecessarily block commands
destined for other AFUs.
Instead of using a global mutex, transition the mutex to be per-AFU. This
will allow commands to only be blocked by siblings of the same AFU.
Signed-off-by: Matthew R. Ochs <mrochs@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Uma Krishnan <ukrishn@xxxxxxxxxxxxxxxxxx>
---
drivers/scsi/cxlflash/common.h | 1 +
drivers/scsi/cxlflash/main.c | 6 +++---
2 files changed, 4 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/cxlflash/common.h b/drivers/scsi/cxlflash/common.h
index 3556b1d..dfcbecb 100644
--- a/drivers/scsi/cxlflash/common.h
+++ b/drivers/scsi/cxlflash/common.h
@@ -240,6 +240,7 @@ struct afu {
struct cxlflash_afu_map __iomem *afu_map; /* entire MMIO map */
atomic_t cmds_active; /* Number of currently active AFU commands */
+ struct mutex sync_active; /* Mutex to serialize AFU commands */
u64 hb;
u32 internal_lun; /* User-desired LUN mode for this AFU */
diff --git a/drivers/scsi/cxlflash/main.c b/drivers/scsi/cxlflash/main.c
index cf0b407..c91e912 100644
--- a/drivers/scsi/cxlflash/main.c
+++ b/drivers/scsi/cxlflash/main.c
@@ -2126,6 +2126,7 @@ static int init_afu(struct cxlflash_cfg *cfg)
cfg->ops->perst_reloads_same_image(cfg->afu_cookie, true);
+ mutex_init(&afu->sync_active);
afu->num_hwqs = afu->desired_hwqs;
for (i = 0; i < afu->num_hwqs; i++) {
rc = init_mc(cfg, i);
@@ -2309,7 +2310,6 @@ static int send_afu_cmd(struct afu *afu, struct sisl_ioarcb *rcb)
char *buf = NULL;
int rc = 0;
int nretry = 0;
- static DEFINE_MUTEX(sync_active);
if (cfg->state != STATE_NORMAL) {
dev_dbg(dev, "%s: Sync not required state=%u\n",
@@ -2317,7 +2317,7 @@ static int send_afu_cmd(struct afu *afu, struct sisl_ioarcb *rcb)
return 0;
}
- mutex_lock(&sync_active);
+ mutex_lock(&afu->sync_active);
atomic_inc(&afu->cmds_active);
buf = kmalloc(sizeof(*cmd) + __alignof__(*cmd) - 1, GFP_KERNEL);
if (unlikely(!buf)) {
@@ -2372,7 +2372,7 @@ static int send_afu_cmd(struct afu *afu, struct sisl_ioarcb *rcb)
*rcb->ioasa = cmd->sa;
out:
atomic_dec(&afu->cmds_active);
- mutex_unlock(&sync_active);
+ mutex_unlock(&afu->sync_active);
kfree(buf);
dev_dbg(dev, "%s: returning rc=%d\n", __func__, rc);
return rc;
--
2.1.0
