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

nguyenb
2020-12-02T08:44:47Z

On 2020-12-02 00:24, Can Guo wrote:
> 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;
Reviewed-by: Bao D. Nguyen <nguyenb@codeaurora.org>