scsi: ufs: Verify UIC locking requirements at runtime

Instead of documenting the locking requirements of the UIC code as
comments, use lockdep_assert_held() such that lockdep verifies the lockdep
requirements at runtime if lockdep is enabled.

Link: https://lore.kernel.org/r/20210722033439.26550-8-bvanassche@acm.org
Cc: Adrian Hunter <adrian.hunter@intel.com>
Cc: Stanley Chu <stanley.chu@mediatek.com>
Cc: Can Guo <cang@codeaurora.org>
Cc: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Avri Altman <avri.altman@wdc.com>
Reviewed-by: Bean Huo <beanhuo@micron.com>
Reviewed-by: Daejun Park <daejun7.park@samsung.com>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 17ef4ceafb22d81530005fb7b8588794650b9458..8e3873e00bc4144854f13509e06d40a0b53039ca 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -2242,15 +2242,15 @@ static inline u8 ufshcd_get_upmcrs(struct ufs_hba *hba)
 }
 
 /**
- * ufshcd_dispatch_uic_cmd - Dispatch UIC commands to unipro layers
+ * ufshcd_dispatch_uic_cmd - Dispatch an UIC command to the Unipro layer
  * @hba: per adapter instance
  * @uic_cmd: UIC command
- *
- * Mutex must be held.
  */
 static inline void
 ufshcd_dispatch_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
 {
+       lockdep_assert_held(&hba->uic_cmd_mutex);
+
        WARN_ON(hba->active_uic_cmd);
 
        hba->active_uic_cmd = uic_cmd;
@@ -2268,11 +2268,10 @@ ufshcd_dispatch_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
 }
 
 /**
- * ufshcd_wait_for_uic_cmd - Wait complectioin of UIC command
+ * ufshcd_wait_for_uic_cmd - Wait for completion of an UIC command
  * @hba: per adapter instance
  * @uic_cmd: UIC command
  *
- * Must be called with mutex held.
  * Returns 0 only if success.
  */
 static int
@@ -2281,6 +2280,8 @@ ufshcd_wait_for_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
        int ret;
        unsigned long flags;
 
+       lockdep_assert_held(&hba->uic_cmd_mutex);
+
        if (wait_for_completion_timeout(&uic_cmd->done,
                                        msecs_to_jiffies(UIC_CMD_TIMEOUT))) {
                ret = uic_cmd->argument2 & MASK_UIC_COMMAND_RESULT;
@@ -2310,14 +2311,15 @@ ufshcd_wait_for_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd)
  * @uic_cmd: UIC command
  * @completion: initialize the completion only if this is set to true
  *
- * Identical to ufshcd_send_uic_cmd() expect mutex. Must be called
- * with mutex held and host_lock locked.
  * Returns 0 only if success.
  */
 static int
 __ufshcd_send_uic_cmd(struct ufs_hba *hba, struct uic_command *uic_cmd,
                      bool completion)
 {
+       lockdep_assert_held(&hba->uic_cmd_mutex);
+       lockdep_assert_held(hba->host->host_lock);
+
        if (!ufshcd_ready_for_uic_cmd(hba)) {
                dev_err(hba->dev,
                        "Controller not ready to accept UIC commands\n");

diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 26f2128b8f3ec57f03e45f003bf783e674fd5950..139e43c6f77689bd04827413646ac61d64e2485a 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -708,7 +708,7 @@ struct ufs_hba_monitor {
  * @priv: pointer to variant specific private data
  * @irq: Irq number of the controller
  * @active_uic_cmd: handle of active UIC command
- * @uic_cmd_mutex: mutex for uic command
+ * @uic_cmd_mutex: mutex for UIC command
  * @tmf_tag_set: TMF tag set.
  * @tmf_queue: Used to allocate TMF tags.
  * @pwr_done: completion for power mode change