From 0fef6bb730c490fcdc4347dbd21646d3ffe62cf5 Mon Sep 17 00:00:00 2001 From: Stanley Chu Date: Sat, 10 Jun 2023 10:15:51 +0800 Subject: [PATCH] scsi: ufs: core: mcq: Fix the incorrect OCS value for the device command In MCQ mode, when a device command uses a hardware queue shared with other commands, a race condition may occur in the following scenario: 1. A device command is completed in CQx with CQE entry "e". 2. The interrupt handler copies the "cqe" pointer to "hba->dev_cmd.cqe" and completes "hba->dev_cmd.complete". 3. The "ufshcd_wait_for_dev_cmd()" function is awakened and retrieves the OCS value from "hba->dev_cmd.cqe". However, there is a possibility that the CQE entry "e" will be overwritten by newly completed commands in CQx, resulting in an incorrect OCS value being received by "ufshcd_wait_for_dev_cmd()". To avoid this race condition, the OCS value should be immediately copied to the struct "lrb" of the device command. Then "ufshcd_wait_for_dev_cmd()" can retrieve the OCS value from the struct "lrb". Fixes: 57b1c0ef89ac ("scsi: ufs: core: mcq: Add support to allocate multiple queues") Suggested-by: Can Guo Signed-off-by: Stanley Chu Link: https://lore.kernel.org/r/20230610021553.1213-2-powen.kao@mediatek.com Tested-by: Po-Wen Kao Reviewed-by: Bart Van Assche Signed-off-by: Martin K. Petersen --- drivers/ufs/core/ufshcd.c | 10 +++++++--- include/ufs/ufshcd.h | 1 - 2 files changed, 7 insertions(+), 4 deletions(-) diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c index add9ec12aa4d..ee4229c0e364 100644 --- a/drivers/ufs/core/ufshcd.c +++ b/drivers/ufs/core/ufshcd.c @@ -3086,7 +3086,7 @@ retry: * not trigger any race conditions. */ hba->dev_cmd.complete = NULL; - err = ufshcd_get_tr_ocs(lrbp, hba->dev_cmd.cqe); + err = ufshcd_get_tr_ocs(lrbp, NULL); if (!err) err = ufshcd_dev_cmd_completion(hba, lrbp); } else { @@ -3182,7 +3182,6 @@ static int ufshcd_exec_dev_cmd(struct ufs_hba *hba, goto out; hba->dev_cmd.complete = &wait; - hba->dev_cmd.cqe = NULL; ufshcd_add_query_upiu_trace(hba, UFS_QUERY_SEND, lrbp->ucd_req_ptr); @@ -5431,6 +5430,7 @@ void ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag, { struct ufshcd_lrb *lrbp; struct scsi_cmnd *cmd; + enum utp_ocs ocs; lrbp = &hba->lrb[task_tag]; lrbp->compl_time_stamp = ktime_get(); @@ -5446,7 +5446,11 @@ void ufshcd_compl_one_cqe(struct ufs_hba *hba, int task_tag, } else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE || lrbp->command_type == UTP_CMD_TYPE_UFS_STORAGE) { if (hba->dev_cmd.complete) { - hba->dev_cmd.cqe = cqe; + if (cqe) { + ocs = le32_to_cpu(cqe->status) & MASK_OCS; + lrbp->utr_descriptor_ptr->header.dword_2 = + cpu_to_le32(ocs); + } complete(hba->dev_cmd.complete); ufshcd_clk_scaling_update_busy(hba); } diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h index d65c9d07694d..92f073bda405 100644 --- a/include/ufs/ufshcd.h +++ b/include/ufs/ufshcd.h @@ -225,7 +225,6 @@ struct ufs_dev_cmd { struct mutex lock; struct completion *complete; struct ufs_query query; - struct cq_entry *cqe; }; /**