Convert the per-device scalar variables that are protected by the
queue lock into atomics such that it becomes safe to access these
variables without holding the queue lock.
Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Hannes Reinecke <hare@xxxxxxx>
Cc: Johannes Thumshirn <jthumshirn@xxxxxxx>
---
drivers/block/skd_main.c | 68 ++++++++++++++++++++++++++----------------------
1 file changed, 37 insertions(+), 31 deletions(-)
diff --git a/drivers/block/skd_main.c b/drivers/block/skd_main.c
index 35343fbf4144..4b92d711d2d3 100644
--- a/drivers/block/skd_main.c
+++ b/drivers/block/skd_main.c
@@ -243,7 +243,7 @@ struct skd_device {
enum skd_drvr_state state;
u32 drive_state;
- u32 in_flight;
+ atomic_t in_flight;
u32 cur_max_queue_depth;
u32 queue_low_water_mark;
u32 dev_max_queue_depth;
@@ -251,8 +251,8 @@ struct skd_device {
u32 num_fitmsg_context;
u32 num_req_context;
- u32 timeout_slot[SKD_N_TIMEOUT_SLOT];
- u32 timeout_stamp;
+ atomic_t timeout_slot[SKD_N_TIMEOUT_SLOT];
+ atomic_t timeout_stamp;
struct skd_fitmsg_context *skmsg_table;
struct skd_request_context *skreq_table;
@@ -517,7 +517,8 @@ static void skd_request_fn(struct request_queue *q)
}
if (blk_queue_stopped(skdev->queue)) {
- if (skdev->in_flight >= skdev->queue_low_water_mark)
+ if (atomic_read(&skdev->in_flight) >=
+ skdev->queue_low_water_mark)
/* There is still some kind of shortage */
return;
@@ -559,9 +560,11 @@ static void skd_request_fn(struct request_queue *q)
/* At this point we know there is a request */
/* Are too many requets already in progress? */
- if (skdev->in_flight >= skdev->cur_max_queue_depth) {
+ if (atomic_read(&skdev->in_flight) >=
+ skdev->cur_max_queue_depth) {
dev_dbg(&skdev->pdev->dev, "qdepth %d, limit %d\n",
- skdev->in_flight, skdev->cur_max_queue_depth);
+ atomic_read(&skdev->in_flight),
+ skdev->cur_max_queue_depth);
break;
}
@@ -647,12 +650,12 @@ static void skd_request_fn(struct request_queue *q)
* Update the active request counts.
* Capture the timeout timestamp.
*/
- skreq->timeout_stamp = skdev->timeout_stamp;
+ skreq->timeout_stamp = atomic_read(&skdev->timeout_stamp);
timo_slot = skreq->timeout_stamp & SKD_TIMEOUT_SLOT_MASK;
- skdev->timeout_slot[timo_slot]++;
- skdev->in_flight++;
+ atomic_inc(&skdev->timeout_slot[timo_slot]);
+ atomic_inc(&skdev->in_flight);
dev_dbg(&skdev->pdev->dev, "req=0x%x busy=%d\n", skreq->id,
- skdev->in_flight);
+ atomic_read(&skdev->in_flight));
/*
* If the FIT msg buffer is full send it.
@@ -805,22 +808,24 @@ static void skd_timer_tick(ulong arg)
skd_timer_tick_not_online(skdev);
goto timer_func_out;
}
- skdev->timeout_stamp++;
- timo_slot = skdev->timeout_stamp & SKD_TIMEOUT_SLOT_MASK;
+ timo_slot = atomic_inc_return(&skdev->timeout_stamp) &
+ SKD_TIMEOUT_SLOT_MASK;
/*
* All requests that happened during the previous use of
* this slot should be done by now. The previous use was
* over 7 seconds ago.
*/
- if (skdev->timeout_slot[timo_slot] == 0)
+ if (atomic_read(&skdev->timeout_slot[timo_slot]) == 0)
goto timer_func_out;
/* Something is overdue */
dev_dbg(&skdev->pdev->dev, "found %d timeouts, draining busy=%d\n",
- skdev->timeout_slot[timo_slot], skdev->in_flight);
+ atomic_read(&skdev->timeout_slot[timo_slot]),
+ atomic_read(&skdev->in_flight));
dev_err(&skdev->pdev->dev, "Overdue IOs (%d), busy %d\n",
- skdev->timeout_slot[timo_slot], skdev->in_flight);
+ atomic_read(&skdev->timeout_slot[timo_slot]),
+ atomic_read(&skdev->in_flight));
skdev->timer_countdown = SKD_DRAINING_TIMO;
skdev->state = SKD_DRVR_STATE_DRAINING_TIMEOUT;
@@ -900,10 +905,10 @@ static void skd_timer_tick_not_online(struct skd_device *skdev)
dev_dbg(&skdev->pdev->dev,
"draining busy [%d] tick[%d] qdb[%d] tmls[%d]\n",
skdev->timo_slot, skdev->timer_countdown,
- skdev->in_flight,
- skdev->timeout_slot[skdev->timo_slot]);
+ atomic_read(&skdev->in_flight),
+ atomic_read(&skdev->timeout_slot[skdev->timo_slot]));
/* if the slot has cleared we can let the I/O continue */
- if (skdev->timeout_slot[skdev->timo_slot] == 0) {
+ if (atomic_read(&skdev->timeout_slot[skdev->timo_slot]) == 0) {
dev_dbg(&skdev->pdev->dev,
"Slot drained, starting queue.\n");
skdev->state = SKD_DRVR_STATE_ONLINE;
@@ -1310,7 +1315,7 @@ static void skd_send_fitmsg(struct skd_device *skdev,
u64 qcmd;
dev_dbg(&skdev->pdev->dev, "dma address 0x%llx, busy=%d\n",
- skmsg->mb_dma_address, skdev->in_flight);
+ skmsg->mb_dma_address, atomic_read(&skdev->in_flight));
dev_dbg(&skdev->pdev->dev, "msg_buf %p\n", skmsg->msg_buf);
qcmd = skmsg->mb_dma_address;
@@ -1550,12 +1555,12 @@ static void skd_release_skreq(struct skd_device *skdev,
* Decrease the number of active requests.
* Also decrements the count in the timeout slot.
*/
- SKD_ASSERT(skdev->in_flight > 0);
- skdev->in_flight -= 1;
+ SKD_ASSERT(atomic_read(&skdev->in_flight) > 0);
+ atomic_dec(&skdev->in_flight);
timo_slot = skreq->timeout_stamp & SKD_TIMEOUT_SLOT_MASK;
- SKD_ASSERT(skdev->timeout_slot[timo_slot] > 0);
- skdev->timeout_slot[timo_slot] -= 1;
+ SKD_ASSERT(atomic_read(&skdev->timeout_slot[timo_slot]) > 0);
+ atomic_dec(&skdev->timeout_slot[timo_slot]);
/*
* Reset backpointer
@@ -1615,8 +1620,8 @@ static int skd_isr_completion_posted(struct skd_device *skdev,
dev_dbg(&skdev->pdev->dev,
"cycle=%d ix=%d got cycle=%d cmdctxt=0x%x stat=%d busy=%d rbytes=0x%x proto=%d\n",
skdev->skcomp_cycle, skdev->skcomp_ix, cmp_cycle,
- cmp_cntxt, cmp_status, skdev->in_flight, cmp_bytes,
- skdev->proto_ver);
+ cmp_cntxt, cmp_status, atomic_read(&skdev->in_flight),
+ cmp_bytes, skdev->proto_ver);
if (cmp_cycle != skdev->skcomp_cycle) {
dev_dbg(&skdev->pdev->dev, "end of completions\n");
@@ -1707,8 +1712,8 @@ static int skd_isr_completion_posted(struct skd_device *skdev,
}
}
- if ((skdev->state == SKD_DRVR_STATE_PAUSING)
- && (skdev->in_flight) == 0) {
+ if (skdev->state == SKD_DRVR_STATE_PAUSING &&
+ atomic_read(&skdev->in_flight) == 0) {
skdev->state = SKD_DRVR_STATE_PAUSED;
wake_up_interruptible(&skdev->waitq);
}
@@ -2053,9 +2058,9 @@ static void skd_recover_requests(struct skd_device *skdev)
}
for (i = 0; i < SKD_N_TIMEOUT_SLOT; i++)
- skdev->timeout_slot[i] = 0;
+ atomic_set(&skdev->timeout_slot[i], 0);
- skdev->in_flight = 0;
+ atomic_set(&skdev->in_flight, 0);
}
static void skd_isr_msg_from_dev(struct skd_device *skdev)
@@ -3714,10 +3719,11 @@ static void skd_log_skdev(struct skd_device *skdev, const char *event)
skd_drive_state_to_str(skdev->drive_state), skdev->drive_state,
skd_skdev_state_to_str(skdev->state), skdev->state);
dev_dbg(&skdev->pdev->dev, " busy=%d limit=%d dev=%d lowat=%d\n",
- skdev->in_flight, skdev->cur_max_queue_depth,
+ atomic_read(&skdev->in_flight), skdev->cur_max_queue_depth,
skdev->dev_max_queue_depth, skdev->queue_low_water_mark);
dev_dbg(&skdev->pdev->dev, " timestamp=0x%x cycle=%d cycle_ix=%d\n",
- skdev->timeout_stamp, skdev->skcomp_cycle, skdev->skcomp_ix);
+ atomic_read(&skdev->timeout_stamp), skdev->skcomp_cycle,
+ skdev->skcomp_ix);
}
static void skd_log_skreq(struct skd_device *skdev,
--
2.14.0
