[PATCH V5 1/3] scsi: ufs: Serialize eh_work with system PM events and async scan

Can Guo
2020-12-02T08:27:49Z

Serialize eh_work with system PM events and async scan to make sure eh_work
does not run in parallel with them.

Reviewed-by: Asutosh Das <asutoshd@codeaurora.org>
Reviewed-by: Hongwu Su<hongwus@codeaurora.org>
Signed-off-by: Can Guo <cang@codeaurora.org>
---
drivers/scsi/ufs/ufshcd.c | 64 +++++++++++++++++++++++++++++------------------
drivers/scsi/ufs/ufshcd.h | 1 +
2 files changed, 41 insertions(+), 24 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 47c544d..f0bb3fc 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -5597,7 +5597,9 @@ static inline void ufshcd_schedule_eh_work(struct ufs_hba *hba)
static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
{
pm_runtime_get_sync(hba->dev);
- if (pm_runtime_suspended(hba->dev)) {
+ if (pm_runtime_status_suspended(hba->dev) || hba->is_sys_suspended) {
+ enum ufs_pm_op pm_op;
+
/*
* Don't assume anything of pm_runtime_get_sync(), if
* resume fails, irq and clocks can be OFF, and powers
@@ -5612,7 +5614,8 @@ static void ufshcd_err_handling_prepare(struct ufs_hba *hba)
if (!ufshcd_is_clkgating_allowed(hba))
ufshcd_setup_clocks(hba, true);
ufshcd_release(hba);
- ufshcd_vops_resume(hba, UFS_RUNTIME_PM);
+ pm_op = hba->is_sys_suspended ? UFS_SYSTEM_PM : UFS_RUNTIME_PM;
+ ufshcd_vops_resume(hba, pm_op);
} else {
ufshcd_hold(hba, false);
if (hba->clk_scaling.is_allowed) {
@@ -5633,7 +5636,7 @@ static void ufshcd_err_handling_unprepare(struct ufs_hba *hba)

static inline bool ufshcd_err_handling_should_stop(struct ufs_hba *hba)
{
- return (hba->ufshcd_state == UFSHCD_STATE_ERROR ||
+ return (!hba->is_powered || hba->ufshcd_state == UFSHCD_STATE_ERROR ||
(!(hba->saved_err || hba->saved_uic_err || hba->force_reset ||
ufshcd_is_link_broken(hba))));
}
@@ -5646,6 +5649,7 @@ static void ufshcd_recover_pm_error(struct ufs_hba *hba)
struct request_queue *q;
int ret;

+ hba->is_sys_suspended = false;
/*
* Set RPM status of hba device to RPM_ACTIVE,
* this also clears its runtime error.
@@ -5704,11 +5708,13 @@ static void ufshcd_err_handler(struct work_struct *work)

hba = container_of(work, struct ufs_hba, eh_work);

+ down(&hba->eh_sem);
spin_lock_irqsave(hba->host->host_lock, flags);
if (ufshcd_err_handling_should_stop(hba)) {
if (hba->ufshcd_state != UFSHCD_STATE_ERROR)
hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
spin_unlock_irqrestore(hba->host->host_lock, flags);
+ up(&hba->eh_sem);
return;
}
ufshcd_set_eh_in_progress(hba);
@@ -5716,20 +5722,18 @@ static void ufshcd_err_handler(struct work_struct *work)
ufshcd_err_handling_prepare(hba);
spin_lock_irqsave(hba->host->host_lock, flags);
ufshcd_scsi_block_requests(hba);
- /*
- * A full reset and restore might have happened after preparation
- * is finished, double check whether we should stop.
- */
- if (ufshcd_err_handling_should_stop(hba)) {
- if (hba->ufshcd_state != UFSHCD_STATE_ERROR)
- hba->ufshcd_state = UFSHCD_STATE_OPERATIONAL;
- goto out;
- }
hba->ufshcd_state = UFSHCD_STATE_RESET;

/* Complete requests that have door-bell cleared by h/w */
ufshcd_complete_requests(hba);

+ /*
+ * A full reset and restore might have happened after preparation
+ * is finished, double check whether we should stop.
+ */
+ if (ufshcd_err_handling_should_stop(hba))
+ goto skip_err_handling;
+
if (hba->dev_quirks & UFS_DEVICE_QUIRK_RECOVERY_FROM_DL_NAC_ERRORS) {
bool ret;

@@ -5737,17 +5741,10 @@ static void ufshcd_err_handler(struct work_struct *work)
/* release the lock as ufshcd_quirk_dl_nac_errors() may sleep */
ret = ufshcd_quirk_dl_nac_errors(hba);
spin_lock_irqsave(hba->host->host_lock, flags);
- if (!ret && !hba->force_reset && ufshcd_is_link_active(hba))
+ if (!ret && ufshcd_err_handling_should_stop(hba))
goto skip_err_handling;
}

- if (hba->force_reset || ufshcd_is_link_broken(hba) ||
- ufshcd_is_saved_err_fatal(hba) ||
- ((hba->saved_err & UIC_ERROR) &&
- (hba->saved_uic_err & (UFSHCD_UIC_DL_NAC_RECEIVED_ERROR |
- UFSHCD_UIC_DL_TCx_REPLAY_ERROR))))
- needs_reset = true;
-
if ((hba->saved_err & (INT_FATAL_ERRORS | UFSHCD_UIC_HIBERN8_MASK)) ||
(hba->saved_uic_err &&
(hba->saved_uic_err != UFSHCD_UIC_PA_GENERIC_ERROR))) {
@@ -5767,8 +5764,14 @@ static void ufshcd_err_handler(struct work_struct *work)
* transfers forcefully because they will get cleared during
* host reset and restore
*/
- if (needs_reset)
+ if (hba->force_reset || ufshcd_is_link_broken(hba) ||
+ ufshcd_is_saved_err_fatal(hba) ||
+ ((hba->saved_err & UIC_ERROR) &&
+ (hba->saved_uic_err & (UFSHCD_UIC_DL_NAC_RECEIVED_ERROR |
+ UFSHCD_UIC_DL_TCx_REPLAY_ERROR)))) {
+ needs_reset = true;
goto do_reset;
+ }

/*
* If LINERESET was caught, UFS might have been put to PWM mode,
@@ -5876,12 +5879,11 @@ static void ufshcd_err_handler(struct work_struct *work)
dev_err_ratelimited(hba->dev, "%s: exit: saved_err 0x%x saved_uic_err 0x%x",
__func__, hba->saved_err, hba->saved_uic_err);
}
-
-out:
ufshcd_clear_eh_in_progress(hba);
spin_unlock_irqrestore(hba->host->host_lock, flags);
ufshcd_scsi_unblock_requests(hba);
ufshcd_err_handling_unprepare(hba);
+ up(&hba->eh_sem);
}

/**
@@ -6856,6 +6858,7 @@ static int ufshcd_reset_and_restore(struct ufs_hba *hba)
*/
scsi_report_bus_reset(hba->host, 0);
if (err) {
+ hba->ufshcd_state = UFSHCD_STATE_ERROR;
hba->saved_err |= saved_err;
hba->saved_uic_err |= saved_uic_err;
}
@@ -7704,8 +7707,10 @@ static void ufshcd_async_scan(void *data, async_cookie_t cookie)
struct ufs_hba *hba = (struct ufs_hba *)data;
int ret;

+ down(&hba->eh_sem);
/* Initialize hba, detect and initialize UFS device */
ret = ufshcd_probe_hba(hba, true);
+ up(&hba->eh_sem);
if (ret)
goto out;

@@ -8718,6 +8723,7 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
int ret = 0;
ktime_t start = ktime_get();

+ down(&hba->eh_sem);
if (!hba || !hba->is_powered)
return 0;

@@ -8748,6 +8754,8 @@ int ufshcd_system_suspend(struct ufs_hba *hba)
hba->curr_dev_pwr_mode, hba->uic_link_state);
if (!ret)
hba->is_sys_suspended = true;
+ else
+ up(&hba->eh_sem);
return ret;
}
EXPORT_SYMBOL(ufshcd_system_suspend);
@@ -8764,8 +8772,10 @@ int ufshcd_system_resume(struct ufs_hba *hba)
int ret = 0;
ktime_t start = ktime_get();

- if (!hba)
+ if (!hba) {
+ up(&hba->eh_sem);
return -EINVAL;
+ }

if (!hba->is_powered || pm_runtime_suspended(hba->dev))
/*
@@ -8781,6 +8791,7 @@ int ufshcd_system_resume(struct ufs_hba *hba)
hba->curr_dev_pwr_mode, hba->uic_link_state);
if (!ret)
hba->is_sys_suspended = false;
+ up(&hba->eh_sem);
return ret;
}
EXPORT_SYMBOL(ufshcd_system_resume);
@@ -8872,6 +8883,7 @@ int ufshcd_shutdown(struct ufs_hba *hba)
{
int ret = 0;

+ down(&hba->eh_sem);
if (!hba->is_powered)
goto out;

@@ -8888,6 +8900,8 @@ int ufshcd_shutdown(struct ufs_hba *hba)
out:
if (ret)
dev_err(hba->dev, "%s failed, err %d\n", __func__, ret);
+ hba->is_powered = false;
+ up(&hba->eh_sem);
/* allow force shutdown even in case of errors */
return 0;
}
@@ -9082,6 +9096,8 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq)
INIT_WORK(&hba->eh_work, ufshcd_err_handler);
INIT_WORK(&hba->eeh_work, ufshcd_exception_event_handler);

+ sema_init(&hba->eh_sem, 1);
+
/* Initialize UIC command mutex */
mutex_init(&hba->uic_cmd_mutex);

diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 47eb143..1e680bf 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -728,6 +728,7 @@ struct ufs_hba {
u32 intr_mask;
u16 ee_ctrl_mask;
bool is_powered;
+ struct semaphore eh_sem;

/* Work Queues */
struct workqueue_struct *eh_wq;
--
Qualcomm Innovation Center, Inc. is a member of Code Aurora Forum, a Linux Foundation Collaborative Project.