| Message ID | 20211130233324.1402448-11-bvanassche@acm.org |
|---|---|
| State | Superseded |
| Headers | show |
| Series | UFS patches for kernel v5.17 | expand |
On 12/1/21 5:48 AM, Adrian Hunter wrote: > I think cmd_queue is not used anymore after this. Let's remove cmd_queue via a separate patch. I have started testing this patch: Subject: [PATCH] scsi: ufs: Remove hba->cmd_queue Suggested-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- drivers/scsi/ufs/ufshcd.c | 11 +---------- drivers/scsi/ufs/ufshcd.h | 2 -- 2 files changed, 1 insertion(+), 12 deletions(-) diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 5b3efc880246..d379c2b0c058 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -9409,7 +9409,6 @@ void ufshcd_remove(struct ufs_hba *hba) ufs_sysfs_remove_nodes(hba->dev); blk_cleanup_queue(hba->tmf_queue); blk_mq_free_tag_set(&hba->tmf_tag_set); - blk_cleanup_queue(hba->cmd_queue); scsi_remove_host(hba->host); /* disable interrupts */ ufshcd_disable_intr(hba, hba->intr_mask); @@ -9630,12 +9629,6 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) goto out_disable; } - hba->cmd_queue = blk_mq_init_queue(&hba->host->tag_set); - if (IS_ERR(hba->cmd_queue)) { - err = PTR_ERR(hba->cmd_queue); - goto out_remove_scsi_host; - } - hba->tmf_tag_set = (struct blk_mq_tag_set) { .nr_hw_queues = 1, .queue_depth = hba->nutmrs, @@ -9644,7 +9637,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) }; err = blk_mq_alloc_tag_set(&hba->tmf_tag_set); if (err < 0) - goto free_cmd_queue; + goto out_remove_scsi_host; hba->tmf_queue = blk_mq_init_queue(&hba->tmf_tag_set); if (IS_ERR(hba->tmf_queue)) { err = PTR_ERR(hba->tmf_queue); @@ -9713,8 +9706,6 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) blk_cleanup_queue(hba->tmf_queue); free_tmf_tag_set: blk_mq_free_tag_set(&hba->tmf_tag_set); -free_cmd_queue: - blk_cleanup_queue(hba->cmd_queue); out_remove_scsi_host: scsi_remove_host(hba->host); out_disable: diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index 411c6015bbfe..88c20f3608c2 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -738,7 +738,6 @@ struct ufs_hba_monitor { * @host: Scsi_Host instance of the driver * @dev: device handle * @lrb: local reference block - * @cmd_queue: Used to allocate command tags from hba->host->tag_set. * @outstanding_tasks: Bits representing outstanding task requests * @outstanding_lock: Protects @outstanding_reqs. * @outstanding_reqs: Bits representing outstanding transfer requests @@ -805,7 +804,6 @@ struct ufs_hba { struct Scsi_Host *host; struct device *dev; - struct request_queue *cmd_queue; /* * This field is to keep a reference to "scsi_device" corresponding to * "UFS device" W-LU.
On 01/12/2021 23:26, Bart Van Assche wrote: > On 12/1/21 5:48 AM, Adrian Hunter wrote: >> I think cmd_queue is not used anymore after this. > > Let's remove cmd_queue via a separate patch. I have started testing this patch: > > Subject: [PATCH] scsi: ufs: Remove hba->cmd_queue > > Suggested-by: Adrian Hunter <adrian.hunter@intel.com> > Signed-off-by: Bart Van Assche <bvanassche@acm.org> Reviewed-by: Adrian Hunter <adrian.hunter@intel.com> > --- > drivers/scsi/ufs/ufshcd.c | 11 +---------- > drivers/scsi/ufs/ufshcd.h | 2 -- > 2 files changed, 1 insertion(+), 12 deletions(-) > > diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c > index 5b3efc880246..d379c2b0c058 100644 > --- a/drivers/scsi/ufs/ufshcd.c > +++ b/drivers/scsi/ufs/ufshcd.c > @@ -9409,7 +9409,6 @@ void ufshcd_remove(struct ufs_hba *hba) > ufs_sysfs_remove_nodes(hba->dev); > blk_cleanup_queue(hba->tmf_queue); > blk_mq_free_tag_set(&hba->tmf_tag_set); > - blk_cleanup_queue(hba->cmd_queue); > scsi_remove_host(hba->host); > /* disable interrupts */ > ufshcd_disable_intr(hba, hba->intr_mask); > @@ -9630,12 +9629,6 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) > goto out_disable; > } > > - hba->cmd_queue = blk_mq_init_queue(&hba->host->tag_set); > - if (IS_ERR(hba->cmd_queue)) { > - err = PTR_ERR(hba->cmd_queue); > - goto out_remove_scsi_host; > - } > - > hba->tmf_tag_set = (struct blk_mq_tag_set) { > .nr_hw_queues = 1, > .queue_depth = hba->nutmrs, > @@ -9644,7 +9637,7 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) > }; > err = blk_mq_alloc_tag_set(&hba->tmf_tag_set); > if (err < 0) > - goto free_cmd_queue; > + goto out_remove_scsi_host; > hba->tmf_queue = blk_mq_init_queue(&hba->tmf_tag_set); > if (IS_ERR(hba->tmf_queue)) { > err = PTR_ERR(hba->tmf_queue); > @@ -9713,8 +9706,6 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) > blk_cleanup_queue(hba->tmf_queue); > free_tmf_tag_set: > blk_mq_free_tag_set(&hba->tmf_tag_set); > -free_cmd_queue: > - blk_cleanup_queue(hba->cmd_queue); > out_remove_scsi_host: > scsi_remove_host(hba->host); > out_disable: > diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h > index 411c6015bbfe..88c20f3608c2 100644 > --- a/drivers/scsi/ufs/ufshcd.h > +++ b/drivers/scsi/ufs/ufshcd.h > @@ -738,7 +738,6 @@ struct ufs_hba_monitor { > * @host: Scsi_Host instance of the driver > * @dev: device handle > * @lrb: local reference block > - * @cmd_queue: Used to allocate command tags from hba->host->tag_set. > * @outstanding_tasks: Bits representing outstanding task requests > * @outstanding_lock: Protects @outstanding_reqs. > * @outstanding_reqs: Bits representing outstanding transfer requests > @@ -805,7 +804,6 @@ struct ufs_hba { > > struct Scsi_Host *host; > struct device *dev; > - struct request_queue *cmd_queue; > /* > * This field is to keep a reference to "scsi_device" corresponding to > * "UFS device" W-LU.
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c index 2d0f59424b00..da4714aaa850 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -128,8 +128,9 @@ EXPORT_SYMBOL_GPL(ufshcd_dump_regs); enum { UFSHCD_MAX_CHANNEL = 0, UFSHCD_MAX_ID = 1, - UFSHCD_CMD_PER_LUN = 32, - UFSHCD_CAN_QUEUE = 32, + UFSHCD_NUM_RESERVED = 1, + UFSHCD_CMD_PER_LUN = 32 - UFSHCD_NUM_RESERVED, + UFSHCD_CAN_QUEUE = 32 - UFSHCD_NUM_RESERVED, }; static const char *const ufshcd_state_name[] = { @@ -2170,6 +2171,7 @@ static inline int ufshcd_hba_capabilities(struct ufs_hba *hba) hba->nutrs = (hba->capabilities & MASK_TRANSFER_REQUESTS_SLOTS) + 1; hba->nutmrs = ((hba->capabilities & MASK_TASK_MANAGEMENT_REQUEST_SLOTS) >> 16) + 1; + hba->reserved_slot = hba->nutrs - 1; /* Read crypto capabilities */ err = ufshcd_hba_init_crypto_capabilities(hba); @@ -2912,30 +2914,15 @@ static int ufshcd_wait_for_dev_cmd(struct ufs_hba *hba, static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, enum dev_cmd_type cmd_type, int timeout) { - struct request_queue *q = hba->cmd_queue; DECLARE_COMPLETION_ONSTACK(wait); - struct request *req; + const u32 tag = hba->reserved_slot; struct ufshcd_lrb *lrbp; int err; - int tag; - down_read(&hba->clk_scaling_lock); + /* Protects use of hba->reserved_slot. */ + lockdep_assert_held(&hba->dev_cmd.lock); - /* - * Get free slot, sleep if slots are unavailable. - * Even though we use wait_event() which sleeps indefinitely, - * the maximum wait time is bounded by SCSI request timeout. - */ - req = blk_mq_alloc_request(q, REQ_OP_DRV_OUT, 0); - if (IS_ERR(req)) { - err = PTR_ERR(req); - goto out_unlock; - } - tag = req->tag; - WARN_ONCE(tag < 0, "Invalid tag %d\n", tag); - /* Set the timeout such that the SCSI error handler is not activated. */ - req->timeout = msecs_to_jiffies(2 * timeout); - blk_mq_start_request(req); + down_read(&hba->clk_scaling_lock); lrbp = &hba->lrb[tag]; WARN_ON(lrbp->cmd); @@ -2953,8 +2940,6 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, (struct utp_upiu_req *)lrbp->ucd_rsp_ptr); out: - blk_mq_free_request(req); -out_unlock: up_read(&hba->clk_scaling_lock); return err; } @@ -6689,23 +6674,16 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, enum dev_cmd_type cmd_type, enum query_opcode desc_op) { - struct request_queue *q = hba->cmd_queue; DECLARE_COMPLETION_ONSTACK(wait); - struct request *req; + const u32 tag = hba->reserved_slot; struct ufshcd_lrb *lrbp; int err = 0; - int tag; u8 upiu_flags; - down_read(&hba->clk_scaling_lock); + /* Protects use of hba->reserved_slot. */ + lockdep_assert_held(&hba->dev_cmd.lock); - req = blk_mq_alloc_request(q, REQ_OP_DRV_OUT, 0); - if (IS_ERR(req)) { - err = PTR_ERR(req); - goto out_unlock; - } - tag = req->tag; - WARN_ONCE(tag < 0, "Invalid tag %d\n", tag); + down_read(&hba->clk_scaling_lock); lrbp = &hba->lrb[tag]; WARN_ON(lrbp->cmd); @@ -6774,9 +6752,6 @@ static int ufshcd_issue_devman_upiu_cmd(struct ufs_hba *hba, ufshcd_add_query_upiu_trace(hba, err ? UFS_QUERY_ERR : UFS_QUERY_COMP, (struct utp_upiu_req *)lrbp->ucd_rsp_ptr); - blk_mq_free_request(req); - -out_unlock: up_read(&hba->clk_scaling_lock); return err; } @@ -9507,8 +9482,8 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) /* Configure LRB */ ufshcd_host_memory_configure(hba); - host->can_queue = hba->nutrs; - host->cmd_per_lun = hba->nutrs; + host->can_queue = hba->nutrs - UFSHCD_NUM_RESERVED; + host->cmd_per_lun = hba->nutrs - UFSHCD_NUM_RESERVED; host->max_id = UFSHCD_MAX_ID; host->max_lun = UFS_MAX_LUNS; host->max_channel = UFSHCD_MAX_CHANNEL; diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index ecc6c545a19d..c3c2792f309f 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -745,6 +745,7 @@ struct ufs_hba_monitor { * @capabilities: UFS Controller Capabilities * @nutrs: Transfer Request Queue depth supported by controller * @nutmrs: Task Management Queue depth supported by controller + * @reserved_slot: Used to submit device commands. Protected by @dev_cmd.lock. * @ufs_version: UFS Version to which controller complies * @vops: pointer to variant specific operations * @priv: pointer to variant specific private data @@ -836,6 +837,7 @@ struct ufs_hba { u32 capabilities; int nutrs; int nutmrs; + u32 reserved_slot; u32 ufs_version; const struct ufs_hba_variant_ops *vops; struct ufs_hba_variant_params *vps;
The following deadlock has been observed on a test setup: * All tags allocated. * The SCSI error handler calls ufshcd_eh_host_reset_handler() * ufshcd_eh_host_reset_handler() queues work that calls ufshcd_err_handler() * ufshcd_err_handler() locks up as follows: Workqueue: ufs_eh_wq_0 ufshcd_err_handler.cfi_jt Call trace: __switch_to+0x298/0x5d8 __schedule+0x6cc/0xa94 schedule+0x12c/0x298 blk_mq_get_tag+0x210/0x480 __blk_mq_alloc_request+0x1c8/0x284 blk_get_request+0x74/0x134 ufshcd_exec_dev_cmd+0x68/0x640 ufshcd_verify_dev_init+0x68/0x35c ufshcd_probe_hba+0x12c/0x1cb8 ufshcd_host_reset_and_restore+0x88/0x254 ufshcd_reset_and_restore+0xd0/0x354 ufshcd_err_handler+0x408/0xc58 process_one_work+0x24c/0x66c worker_thread+0x3e8/0xa4c kthread+0x150/0x1b4 ret_from_fork+0x10/0x30 Fix this lockup by making ufshcd_exec_dev_cmd() allocate a reserved request. Signed-off-by: Bart Van Assche <bvanassche@acm.org> --- drivers/scsi/ufs/ufshcd.c | 53 +++++++++++---------------------------- drivers/scsi/ufs/ufshcd.h | 2 ++ 2 files changed, 16 insertions(+), 39 deletions(-)