The patch below does not apply to the 5.4-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From f5ef336fd2e4c36dedae4e7ca66cf5349d6fda62 Mon Sep 17 00:00:00 2001

From: Adrian Hunter adrian.hunter@intel.com Date: Wed, 22 Sep 2021 12:10:59 +0300 Subject: [PATCH] scsi: ufs: core: Fix task management completion

The UFS driver uses blk_mq_tagset_busy_iter() when identifying task management requests to complete, however blk_mq_tagset_busy_iter() doesn't work.

blk_mq_tagset_busy_iter() only iterates requests dispatched by the block layer. That appears as if it might have started since commit 37f4a24c2469 ("blk-mq: centralise related handling into blk_mq_get_driver_tag") which removed 'data->hctx->tags->rqs[rq->tag] = rq' from blk_mq_rq_ctx_init() which gets called:

blk_get_request blk_mq_alloc_request __blk_mq_alloc_request blk_mq_rq_ctx_init

Since UFS task management requests are not dispatched by the block layer, hctx->tags->rqs[rq->tag] remains NULL, and since blk_mq_tagset_busy_iter() relies on finding requests using hctx->tags->rqs[rq->tag], UFS task management requests are never found by blk_mq_tagset_busy_iter().

By using blk_mq_tagset_busy_iter(), the UFS driver was relying on internal details of the block layer, which was fragile and subsequently got broken. Fix by removing the use of blk_mq_tagset_busy_iter() and having the driver keep track of task management requests.

Link: https://lore.kernel.org/r/20210922091059.4040-1-adrian.hunter@intel.com Fixes: 1235fc569e0b ("scsi: ufs: core: Fix task management request completion timeout") Fixes: 69a6c269c097 ("scsi: ufs: Use blk_{get,put}_request() to allocate and free TMFs") Cc: stable@vger.kernel.org Tested-by: Bart Van Assche bvanassche@acm.org Reviewed-by: Bart Van Assche bvanassche@acm.org Signed-off-by: Adrian Hunter adrian.hunter@intel.com 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 188de6f91050..95be7ecdfe10 100644 --- a/drivers/scsi/ufs/ufshcd.c +++ b/drivers/scsi/ufs/ufshcd.c @@ -6377,27 +6377,6 @@ static irqreturn_t ufshcd_check_errors(struct ufs_hba *hba, u32 intr_status) return retval; }

-struct ctm_info { - struct ufs_hba *hba; - unsigned long pending; - unsigned int ncpl; -}; - -static bool ufshcd_compl_tm(struct request *req, void *priv, bool reserved) -{ - struct ctm_info *const ci = priv; - struct completion *c; - - WARN_ON_ONCE(reserved); - if (test_bit(req->tag, &ci->pending)) - return true; - ci->ncpl++; - c = req->end_io_data; - if (c) - complete(c); - return true; -} - /** * ufshcd_tmc_handler - handle task management function completion * @hba: per adapter instance @@ -6408,18 +6387,24 @@ static bool ufshcd_compl_tm(struct request *req, void *priv, bool reserved) */ static irqreturn_t ufshcd_tmc_handler(struct ufs_hba *hba) { - unsigned long flags; - struct request_queue *q = hba->tmf_queue; - struct ctm_info ci = { - .hba = hba, - }; + unsigned long flags, pending, issued; + irqreturn_t ret = IRQ_NONE; + int tag; + + pending = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL);

spin_lock_irqsave(hba->host->host_lock, flags); - ci.pending = ufshcd_readl(hba, REG_UTP_TASK_REQ_DOOR_BELL); - blk_mq_tagset_busy_iter(q->tag_set, ufshcd_compl_tm, &ci); + issued = hba->outstanding_tasks & ~pending; + for_each_set_bit(tag, &issued, hba->nutmrs) { + struct request *req = hba->tmf_rqs[tag]; + struct completion *c = req->end_io_data; + + complete(c); + ret = IRQ_HANDLED; + } spin_unlock_irqrestore(hba->host->host_lock, flags);

- return ci.ncpl ? IRQ_HANDLED : IRQ_NONE; + return ret; }

/** @@ -6542,9 +6527,9 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba, ufshcd_hold(hba, false);

spin_lock_irqsave(host->host_lock, flags); - blk_mq_start_request(req);

task_tag = req->tag; + hba->tmf_rqs[req->tag] = req; treq->upiu_req.req_header.dword_0 |= cpu_to_be32(task_tag);

memcpy(hba->utmrdl_base_addr + task_tag, treq, sizeof(*treq)); @@ -6585,6 +6570,7 @@ static int __ufshcd_issue_tm_cmd(struct ufs_hba *hba, }

spin_lock_irqsave(hba->host->host_lock, flags); + hba->tmf_rqs[req->tag] = NULL; __clear_bit(task_tag, &hba->outstanding_tasks); spin_unlock_irqrestore(hba->host->host_lock, flags);

@@ -9635,6 +9621,12 @@ int ufshcd_init(struct ufs_hba *hba, void __iomem *mmio_base, unsigned int irq) err = PTR_ERR(hba->tmf_queue); goto free_tmf_tag_set; } + hba->tmf_rqs = devm_kcalloc(hba->dev, hba->nutmrs, + sizeof(*hba->tmf_rqs), GFP_KERNEL); + if (!hba->tmf_rqs) { + err = -ENOMEM; + goto free_tmf_queue; + }

/* Reset the attached device */ ufshcd_device_reset(hba); diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h index f0da5d3db1fa..41f6e06f9185 100644 --- a/drivers/scsi/ufs/ufshcd.h +++ b/drivers/scsi/ufs/ufshcd.h @@ -828,6 +828,7 @@ struct ufs_hba {

struct blk_mq_tag_set tmf_tag_set; struct request_queue *tmf_queue; + struct request **tmf_rqs;

struct uic_command *active_uic_cmd; struct mutex uic_cmd_mutex;