From:   "Bao D. Nguyen" <quic_nguyenb@quicinc.com>
To:     <quic_asutoshd@quicinc.com>, <quic_cang@quicinc.com>,
        <bvanassche@acm.org>, <mani@kernel.org>,
        <stanley.chu@mediatek.com>, <adrian.hunter@intel.com>,
        <beanhuo@micron.com>, <avri.altman@wdc.com>,
        <martin.petersen@oracle.com>
CC:     <linux-scsi@vger.kernel.org>,
        "Bao D. Nguyen" <quic_nguyenb@quicinc.com>,
        Alim Akhtar <alim.akhtar@samsung.com>,
        "James E.J. Bottomley" <jejb@linux.ibm.com>,
        Arthur Simchaev <Arthur.Simchaev@wdc.com>,
        open list <linux-kernel@vger.kernel.org>
Subject: [RFC PATCH v2 1/3] ufs: mcq: Add supporting functions for mcq abort
Date:   Wed, 8 Mar 2023 21:28:55 -0800
Message-ID: <68b786f390dbd93218a482d18c513bc332e82da3.1678338926.git.quic_nguyenb@quicinc.com>
In-Reply-To: <cover.1678338926.git.quic_nguyenb@quicinc.com>
References: <cover.1678338926.git.quic_nguyenb@quicinc.com>
MIME-Version: 1.0
Content-Type: text/plain
Precedence: bulk

Add supporting functions to handle ufs abort in mcq mode.

Signed-off-by: Bao D. Nguyen <quic_nguyenb@quicinc.com>
---
 drivers/ufs/core/ufs-mcq.c     | 181 +++++++++++++++++++++++++++++++++++++++++
 drivers/ufs/core/ufshcd-priv.h |  14 ++++
 drivers/ufs/core/ufshcd.c      |   3 +-
 include/ufs/ufshcd.h           |   1 +
 include/ufs/ufshci.h           |  16 ++++
 5 files changed, 214 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
index 31df052..4c33c1a 100644
--- a/drivers/ufs/core/ufs-mcq.c
+++ b/drivers/ufs/core/ufs-mcq.c
@@ -12,6 +12,9 @@
 #include <linux/module.h>
 #include <linux/platform_device.h>
 #include "ufshcd-priv.h"
+#include <linux/delay.h>
+#include <scsi/scsi_cmnd.h>
+#include <linux/bitfield.h>
 
 #define MAX_QUEUE_SUP GENMASK(7, 0)
 #define UFS_MCQ_MIN_RW_QUEUES 2
@@ -27,6 +30,9 @@
 #define MCQ_ENTRY_SIZE_IN_DWORD	8
 #define CQE_UCD_BA GENMASK_ULL(63, 7)
 
+/* Max mcq register polling time in millisecond unit */
+#define MCQ_POLL_MS 500
+
 static int rw_queue_count_set(const char *val, const struct kernel_param *kp)
 {
 	return param_set_uint_minmax(val, kp, UFS_MCQ_MIN_RW_QUEUES,
@@ -429,3 +435,178 @@ int ufshcd_mcq_init(struct ufs_hba *hba)
 	host->host_tagset = 1;
 	return 0;
 }
+
+static int ufshcd_mcq_poll_register(void __iomem *reg, u32 mask,
+			u32 val, unsigned long timeout_ms)
+{
+	unsigned long timeout = jiffies + msecs_to_jiffies(timeout_ms);
+	int err = 0;
+
+	/* ignore bits that we don't intend to wait on */
+	val = val & mask;
+
+	while ((readl(reg) & mask) != val) {
+		usleep_range(10, 50);
+		if (time_after(jiffies, timeout)) {
+			err = -ETIMEDOUT;
+			break;
+		}
+	}
+
+	return err;
+}
+
+static int ufshcd_mcq_sq_stop(struct ufs_hba *hba, struct ufs_hw_queue *hwq)
+{
+	void __iomem *reg;
+	u32 i = hwq->id;
+	int err;
+
+	writel(SQ_STOP, mcq_opr_base(hba, OPR_SQD, i) + REG_SQRTC);
+	reg = mcq_opr_base(hba, OPR_SQD, i) + REG_SQRTS;
+	err = ufshcd_mcq_poll_register(reg, SQ_STS, SQ_STS, MCQ_POLL_MS);
+	if (err)
+		dev_err(hba->dev, "%s: failed. hwq-id=%d, err=%d\n",
+			__func__, i, err);
+	return err;
+}
+
+static int ufshcd_mcq_sq_start(struct ufs_hba *hba, struct ufs_hw_queue *hwq)
+{
+	void __iomem *reg;
+	u32 i = hwq->id;
+	int err;
+
+	writel(SQ_START, mcq_opr_base(hba, OPR_SQD, i) + REG_SQRTC);
+	reg = mcq_opr_base(hba, OPR_SQD, i) + REG_SQRTS;
+	err = ufshcd_mcq_poll_register(reg, SQ_STS, 0, MCQ_POLL_MS);
+	if (err)
+		dev_err(hba->dev, "%s: failed. hwq-id=%d, err=%d\n",
+			__func__, i, err);
+	return err;
+}
+
+/**
+ * ufshcd_mcq_sq_cleanup - Clean up Submission Queue resources
+ * associated with the pending command.
+ * @hba - per adapter instance.
+ * @task_tag - The command's task tag.
+ * @result - Result of the Clean up operation.
+ *
+ * Returns 0 and result on completion. Returns error code if
+ * the operation fails.
+ */
+int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag, int *result)
+{
+	struct ufshcd_lrb *lrbp = &hba->lrb[task_tag];
+	struct scsi_cmnd *cmd = lrbp->cmd;
+	struct ufs_hw_queue *hwq;
+	void __iomem *reg, *opr_sqd_base;
+	u32 nexus, i;
+	int err;
+
+	hwq = ufshcd_mcq_req_to_hwq(hba, scsi_cmd_to_rq(cmd));
+	i = hwq->id;
+
+	spin_lock(&hwq->sq_lock);
+
+	/* stop the SQ fetching before working on it */
+	err = ufshcd_mcq_sq_stop(hba, hwq);
+	if (err)
+		goto unlock;
+
+	/* SQCTI = EXT_IID, IID, LUN, Task Tag */
+	nexus = lrbp->lun << 8 | task_tag;
+	opr_sqd_base = mcq_opr_base(hba, OPR_SQD, i);
+	writel(nexus, opr_sqd_base + REG_SQCTI);
+
+	/* SQRTCy.ICU = 1 */
+	writel(SQ_ICU, opr_sqd_base + REG_SQRTC);
+
+	/* Poll SQRTSy.CUS = 1. Return result from SQRTSy.RTC */
+	reg = opr_sqd_base + REG_SQRTS;
+	err = ufshcd_mcq_poll_register(reg, SQ_CUS, SQ_CUS, MCQ_POLL_MS);
+	if (err) {
+		dev_err(hba->dev, "%s: failed. hwq=%d, lun=0x%x, tag=%d\n",
+			__func__, i, lrbp->lun, task_tag);
+		*result = FIELD_GET(SQ_ICU_ERR_CODE_MASK, readl(reg));
+	}
+
+	err = ufshcd_mcq_sq_start(hba, hwq);
+
+unlock:
+	spin_unlock(&hwq->sq_lock);
+	return err;
+}
+
+static u64 ufshcd_mcq_get_cmd_desc_addr(struct ufs_hba *hba,
+					int task_tag)
+{
+	struct ufshcd_lrb *lrbp = &hba->lrb[task_tag];
+	__le32 hi = lrbp->utr_descriptor_ptr->command_desc_base_addr_hi;
+	__le32 lo = lrbp->utr_descriptor_ptr->command_desc_base_addr_lo;
+
+	return le64_to_cpu((__le64)hi << 32 | lo);
+}
+
+/**
+ * ufshcd_mcq_nullify_cmd - Nullify utrd. Host controller does not fetch
+ * transfer with Command Type = 0xF. post the Completion Queue with OCS=ABORTED.
+ * @hba - per adapter instance.
+ * @hwq - Hardware Queue of the nullified utrd.
+ */
+static void ufshcd_mcq_nullify_cmd(struct ufs_hba *hba, struct ufs_hw_queue *hwq)
+{
+	struct utp_transfer_req_desc *utrd;
+	u32 dword_0;
+
+	utrd = (struct utp_transfer_req_desc *)(hwq->sqe_base_addr +
+			hwq->id * sizeof(struct utp_transfer_req_desc));
+	dword_0 = le32_to_cpu(utrd->header.dword_0);
+	dword_0 &= ~UPIU_COMMAND_TYPE_MASK;
+	dword_0 |= FIELD_PREP(UPIU_COMMAND_TYPE_MASK, 0xF);
+	utrd->header.dword_0 = cpu_to_le32(dword_0);
+}
+
+/**
+ * ufshcd_mcq_sqe_search - Search for the cmd in the Submission Queue (SQ)
+ * @hba - per adapter instance.
+ * @hwq - Hardware Queue to be searched.
+ * @task_tag - The command's task tag.
+ *
+ * Returns true if the SQE containing the command is present in the SQ
+ * (not fetched by the controller); returns false if the SQE is not in the SQ.
+ */
+static bool ufshcd_mcq_sqe_search(struct ufs_hba *hba,
+		struct ufs_hw_queue *hwq, int task_tag)
+{
+	struct utp_transfer_req_desc *utrd;
+	u32 mask = hwq->max_entries - 1;
+	bool ret = false;
+	u64 addr, match;
+	u32 i;
+
+	spin_lock(&hwq->sq_lock);
+
+	ufshcd_mcq_update_sq_head_slot(hwq);
+	if (ufshcd_mcq_is_sq_empty(hwq))
+		goto out;
+
+	addr = ufshcd_mcq_get_cmd_desc_addr(hba, task_tag);
+	i = hwq->sq_head_slot;
+	while (i != hwq->sq_tail_slot) {
+		utrd = (struct utp_transfer_req_desc *)(hwq->sqe_base_addr +
+				i * sizeof(struct utp_transfer_req_desc));
+		match = le64_to_cpu((__le64)utrd->command_desc_base_addr_hi << 32 |
+				utrd->command_desc_base_addr_lo) & CQE_UCD_BA;
+		if (addr == match) {
+			ret = true;
+			goto out;
+		}
+		i = (i + 1) & mask;
+	}
+
+out:
+	spin_unlock(&hwq->sq_lock);
+	return ret;
+}
diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
index 529f850..e25a852 100644
--- a/drivers/ufs/core/ufshcd-priv.h
+++ b/drivers/ufs/core/ufshcd-priv.h
@@ -78,6 +78,8 @@ struct ufs_hw_queue *ufshcd_mcq_req_to_hwq(struct ufs_hba *hba,
 unsigned long ufshcd_mcq_poll_cqe_lock(struct ufs_hba *hba,
 				       struct ufs_hw_queue *hwq);
 
+int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag, int *result);
+
 #define UFSHCD_MCQ_IO_QUEUE_OFFSET	1
 #define SD_ASCII_STD true
 #define SD_RAW false
@@ -403,4 +405,16 @@ static inline struct cq_entry *ufshcd_mcq_cur_cqe(struct ufs_hw_queue *q)
 
 	return cqe + q->cq_head_slot;
 }
+
+static inline void ufshcd_mcq_update_sq_head_slot(struct ufs_hw_queue *q)
+{
+	u32 val = readl(q->mcq_sq_head);
+
+	q->sq_head_slot = val / sizeof(struct utp_transfer_req_desc);
+}
+
+static inline bool ufshcd_mcq_is_sq_empty(struct ufs_hw_queue *q)
+{
+	return q->sq_head_slot == q->sq_tail_slot;
+}
 #endif /* _UFSHCD_PRIV_H_ */
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 629442c..49a05909 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -56,7 +56,8 @@
 #define NOP_OUT_RETRIES    10
 /* Timeout after 50 msecs if NOP OUT hangs without response */
 #define NOP_OUT_TIMEOUT    50 /* msecs */
-
+/* Maximum MCQ registers polling time */
+#define MCQ_POLL_TIMEOUT   500
 /* Query request retries */
 #define QUERY_REQ_RETRIES 3
 /* Query request timeout */
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 05e4164..6ee532e0 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -1105,6 +1105,7 @@ struct ufs_hw_queue {
 	u32 max_entries;
 	u32 id;
 	u32 sq_tail_slot;
+	u32 sq_head_slot;
 	spinlock_t sq_lock;
 	u32 cq_tail_slot;
 	u32 cq_head_slot;
diff --git a/include/ufs/ufshci.h b/include/ufs/ufshci.h
index 11424bb..252e731 100644
--- a/include/ufs/ufshci.h
+++ b/include/ufs/ufshci.h
@@ -99,6 +99,9 @@ enum {
 enum {
 	REG_SQHP		= 0x0,
 	REG_SQTP		= 0x4,
+	REG_SQRTC		= 0x8,
+	REG_SQCTI		= 0xC,
+	REG_SQRTS		= 0x10,
 };
 
 enum {
@@ -111,6 +114,19 @@ enum {
 	REG_CQIE		= 0x4,
 };
 
+enum {
+	SQ_START		= 0x0,
+	SQ_STOP			= 0x1,
+	SQ_ICU			= 0x2,
+};
+
+enum {
+	SQ_STS			= 0x1,
+	SQ_CUS			= 0x2,
+};
+
+#define SQ_ICU_ERR_CODE_MASK		GENMASK(7, 4)
+#define UPIU_COMMAND_TYPE_MASK		GENMASK(31, 28)
 #define UFS_MASK(mask, offset)		((mask) << (offset))
 
 /* UFS Version 08h */
-- 
2.7.4