Manage TMF tags with blk_{get,put}_request() instead of
ufshcd_get_tm_free_slot() / ufshcd_put_tm_slot(). Store a per-request
completion pointer in request.end_io_data instead of using a waitqueue
to report TMF completion.
Cc: Yaniv Gardi <ygardi@xxxxxxxxxxxxxx>
Cc: Subhash Jadavani <subhashj@xxxxxxxxxxxxxx>
Cc: Stanley Chu <stanley.chu@xxxxxxxxxxxx>
Cc: Avri Altman <avri.altman@xxxxxxx>
Cc: Tomas Winkler <tomas.winkler@xxxxxxxxx>
Signed-off-by: Bart Van Assche <bvanassche@xxxxxxx>
---
drivers/scsi/ufs/ufshcd.c | 84 +++++++++++++++++----------------------
drivers/scsi/ufs/ufshcd.h | 9 -----
2 files changed, 36 insertions(+), 57 deletions(-)
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index c8124db6665e..a2100f9d51a3 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -645,40 +645,6 @@ static inline int ufshcd_get_tr_ocs(struct ufshcd_lrb *lrbp)
return le32_to_cpu(lrbp->utr_descriptor_ptr->header.dword_2) & MASK_OCS;
}
-/**
- * ufshcd_get_tm_free_slot - get a free slot for task management request
- * @hba: per adapter instance
- * @free_slot: pointer to variable with available slot value
- *
- * Get a free tag and lock it until ufshcd_put_tm_slot() is called.
- * Returns 0 if free slot is not available, else return 1 with tag value
- * in @free_slot.
- */
-static bool ufshcd_get_tm_free_slot(struct ufs_hba *hba, int *free_slot)
-{
- int tag;
- bool ret = false;
-
- if (!free_slot)
- goto out;
-
- do {
- tag = find_first_zero_bit(&hba->tm_slots_in_use, hba->nutmrs);
- if (tag >= hba->nutmrs)
- goto out;
- } while (test_and_set_bit_lock(tag, &hba->tm_slots_in_use));
-
- *free_slot = tag;
- ret = true;
-out:
- return ret;
-}
-
-static inline void ufshcd_put_tm_slot(struct ufs_hba *hba, int slot)
-{
- clear_bit_unlock(slot, &hba->tm_slots_in_use);
-}
-
/**
* ufshcd_utrl_clear - Clear a bit in UTRLCLR register
* @hba: per adapter instance
@@ -5519,17 +5485,35 @@ static void ufshcd_check_errors(struct ufs_hba *hba)
*/
}
+struct ctm_info {
+ struct ufs_hba *hba;
+ unsigned long pending;
+};
+
+static bool ufshcd_compl_tm(struct request *req, void *priv, bool reserved)
+{
+ const struct ctm_info *const ci = priv;
+ struct completion *c;
+
+ if (!reserved || test_bit(req->tag, &ci->pending))
+ return true;
+ c = req->end_io_data;
+ if (c)
+ complete(c);
+ return true;
+}
+
/**
* ufshcd_tmc_handler - handle task management function completion
* @hba: per adapter instance
*/
static void ufshcd_tmc_handler(struct ufs_hba *hba)
{
- u32 tm_doorbell;
+ struct request_queue *q = hba->tag_alloc_queue;
+ struct ctm_info ci = { .hba = hba };
- tm_doorbell = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);
- hba->tm_condition = tm_doorbell ^ hba->outstanding_tasks;
- wake_up(&hba->tm_wq);
+ ci.pending = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);
+ blk_mq_tagset_busy_iter(q->tag_set, ufshcd_compl_tm, &ci);
}
/**
@@ -5622,7 +5606,10 @@ static int ufshcd_clear_tm_cmd(struct ufs_hba *hba, int tag)
static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
struct utp_task_req_desc *treq, u8 tm_function)
{
+ struct request_queue *q = hba->tag_alloc_queue;
struct Scsi_Host *host = hba->host;
+ DECLARE_COMPLETION_ONSTACK(wait);
+ struct request *req;
unsigned long flags;
int free_slot, task_tag, err;
@@ -5631,7 +5618,10 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
* Even though we use wait_event() which sleeps indefinitely,
* the maximum wait time is bounded by %TM_CMD_TIMEOUT.
*/
- wait_event(hba->tm_tag_wq, ufshcd_get_tm_free_slot(hba, &free_slot));
+ req = blk_get_request(q, REQ_OP_DRV_OUT, BLK_MQ_REQ_RESERVED);
+ 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);
@@ -5657,10 +5647,14 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
ufshcd_add_tm_upiu_trace(hba, task_tag, "tm_send");
/* wait until the task management command is completed */
- err = wait_event_timeout(hba->tm_wq,
- test_bit(free_slot, &hba->tm_condition),
+ err = wait_for_completion_io_timeout(&wait,
msecs_to_jiffies(TM_CMD_TIMEOUT));
if (!err) {
+ /*
+ * Make sure that ufshcd_compl_tm() does not trigger a
+ * use-after-free.
+ */
+ req->end_io_data = NULL;
ufshcd_add_tm_upiu_trace(hba, task_tag, "tm_complete_err");
dev_err(hba->dev, "%s: task management cmd 0x%.2x timed-out\n",
__func__, tm_function);
@@ -5679,9 +5673,7 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba,
__clear_bit(free_slot, &hba->outstanding_tasks);
spin_unlock_irqrestore(hba->host->host_lock, flags);
- clear_bit(free_slot, &hba->tm_condition);
- ufshcd_put_tm_slot(hba, free_slot);
- wake_up(&hba->tm_tag_wq);
+ blk_put_request(req);
ufshcd_release(hba);
return err;
@@ -8315,10 +8307,6 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
hba->max_pwr_info.is_valid = false;
- /* Initailize wait queue for task management */
- init_waitqueue_head(&hba->tm_wq);
- init_waitqueue_head(&hba->tm_tag_wq);
-
/* Initialize work queues */
INIT_WORK(&hba->eh_work, ufshcd_err_handler);
INIT_WORK(&hba->eeh_work, ufshcd_exception_event_handler);
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 8fa33fb71237..0d8867db43db 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -493,11 +493,7 @@ struct ufs_stats {
* @irq: Irq number of the controller
* @active_uic_cmd: handle of active UIC command
* @uic_cmd_mutex: mutex for uic command
- * @tm_wq: wait queue for task management
- * @tm_tag_wq: wait queue for free task management slots
- * @tm_slots_in_use: bit map of task management request slots in use
* @pwr_done: completion for power mode change
- * @tm_condition: condition variable for task management
* @ufshcd_state: UFSHCD states
* @eh_flags: Error handling flags
* @intr_mask: Interrupt Mask Bits
@@ -641,11 +637,6 @@ struct ufs_hba {
/* Device deviations from standard UFS device spec. */
unsigned int dev_quirks;
- wait_queue_head_t tm_wq;
- wait_queue_head_t tm_tag_wq;
- unsigned long tm_condition;
- unsigned long tm_slots_in_use;
-
struct uic_command *active_uic_cmd;
struct mutex uic_cmd_mutex;
struct completion *uic_async_done;
--
2.24.0.rc1.363.gb1bccd3e3d-goog
