ufshcd_compl_tm() looks for all 0 bits in the REG_UTP_TASK_REQ_DOOR_BELL
and call complete() for each req who has the req->end_io_data set. There
can be a race condition btw tmc send/compl, because the req->end_io_data is
set, in __ufshcd_issue_tm_cmd(), without host lock protection, so it is
possible that when ufshcd_compl_tm() checks the req->end_io_data, it is set
but the corresponding tag has not been set in REG_UTP_TASK_REQ_DOOR_BELL.
Thus, ufshcd_tmc_handler() may wrongly complete TMRs which have not been
sent out. Fix it by protecting req->end_io_data with host lock, and let
ufshcd_compl_tm() only handle those tm cmds which have been completed
instead of looking for 0 bits in the REG_UTP_TASK_REQ_DOOR_BELL.
Fixes: 69a6c269c097 ("scsi: ufs: Use blk_{get,put}_request() to allocate and
free TMFs")
Signed-off-by: Can Guo <c...@codeaurora.org>
---
drivers/scsi/ufs/ufshcd.c | 33 +++++++++++++++++++++------------
1 file changed, 21 insertions(+), 12 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c0c5925..43894a3 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -6225,7 +6225,7 @@ static irqreturn_t ufshcd_check_errors(struct ufs_hba
*hba)
struct ctm_info {
struct ufs_hba *hba;
- unsigned long pending;
+ unsigned long completed;
unsigned int ncpl;
};
@@ -6234,13 +6234,13 @@ static bool ufshcd_compl_tm(struct request *req, void
*priv, bool reserved)
struct ctm_info *const ci = priv;
struct completion *c;
- WARN_ON_ONCE(reserved);
- if (test_bit(req->tag, &ci->pending))
- return true;
- ci->ncpl++;
- c = req->end_io_data;
- if (c)
- complete(c);
+ if (test_bit(req->tag, &ci->completed)) {
+ __clear_bit(req->tag, &ci->hba->outstanding_tasks);
+ ci->ncpl++;
+ c = req->end_io_data;
+ if (c)
+ complete(c);
+ }
return true;
}
@@ -6255,12 +6255,19 @@ static bool ufshcd_compl_tm(struct request *req, void
*priv, bool reserved)
static irqreturn_t ufshcd_tmc_handler(struct ufs_hba *hba)
{
struct request_queue *q = hba->tmf_queue;
+ u32 tm_doorbell;
+ unsigned long completed;
struct ctm_info ci = {
- .hba = hba,
- .pending = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL),
+ .hba = hba,
+ .ncpl = 0,
};
- blk_mq_tagset_busy_iter(q->tag_set, ufshcd_compl_tm, &ci);
+ tm_doorbell = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);
+ completed = tm_doorbell ^ hba->outstanding_tasks;
+ if (completed) {
+ ci.completed = completed;
+ blk_mq_tagset_busy_iter(q->tag_set, ufshcd_compl_tm, &ci);
+ }
return ci.ncpl ? IRQ_HANDLED : IRQ_NONE;
}
@@ -6388,12 +6395,12 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
if (IS_ERR(req))
return PTR_ERR(req);
- req->end_io_data = &wait;
free_slot = req->tag;
WARN_ON_ONCE(free_slot < 0 || free_slot >= hba->nutmrs);
ufshcd_hold(hba, false);
spin_lock_irqsave(host->host_lock, flags);
+ req->end_io_data = &wait;
task_tag = hba->nutrs + free_slot;
blk_mq_start_request(req);
@@ -6420,11 +6427,13 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
err = wait_for_completion_io_timeout(&wait,
msecs_to_jiffies(TM_CMD_TIMEOUT));
if (!err) {
+ spin_lock_irqsave(hba->host->host_lock, flags);
/*
* Make sure that ufshcd_compl_tm() does not trigger a
* use-after-free.
*/
req->end_io_data = NULL;
+ spin_unlock_irqrestore(hba->host->host_lock, flags);
ufshcd_add_tm_upiu_trace(hba, task_tag, UFS_TM_ERR);
dev_err(hba->dev, "%s: task management cmd 0x%.2x timed-out\n",
__func__, tm_function);
--
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Foundation Collaborative Project.
