[PATCH v7 3/7] ufs: mcq: Add supporting functions for mcq abort

Bao D. Nguyen
2023-05-29T22:13:55Z

Add supporting functions to handle ufs abort in mcq mode.

Signed-off-by: Bao D. Nguyen <quic_nguyenb@quicinc.com>
Reviewed-by: Bart Van Assche <bvanassche@acm.org>
---
drivers/ufs/core/ufs-mcq.c | 167 +++++++++++++++++++++++++++++++++++++++++
drivers/ufs/core/ufshcd-priv.h | 10 +++
drivers/ufs/core/ufshcd.c | 1 -
include/ufs/ufshcd.h | 3 +
include/ufs/ufshci.h | 17 +++++
5 files changed, 197 insertions(+), 1 deletion(-)

diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
index 202ff71..655f220 100644
--- a/drivers/ufs/core/ufs-mcq.c
+++ b/drivers/ufs/core/ufs-mcq.c
@@ -12,6 +12,10 @@
#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>
+#include <linux/iopoll.h>

#define MAX_QUEUE_SUP GENMASK(7, 0)
#define UFS_MCQ_MIN_RW_QUEUES 2
@@ -27,6 +31,9 @@
#define MCQ_ENTRY_SIZE_IN_DWORD 8
#define CQE_UCD_BA GENMASK_ULL(63, 7)

+/* Max mcq register polling time in microseconds */
+#define MCQ_POLL_US 500000
+
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,
@@ -419,6 +426,7 @@ int ufshcd_mcq_init(struct ufs_hba *hba)
hwq->max_entries = hba->nutrs;
spin_lock_init(&hwq->sq_lock);
spin_lock_init(&hwq->cq_lock);
+ mutex_init(&hwq->sq_mutex);
}

/* The very first HW queue serves device commands */
@@ -429,3 +437,162 @@ int ufshcd_mcq_init(struct ufs_hba *hba)
host->host_tagset = 1;
return 0;
}
+
+static int ufshcd_mcq_sq_stop(struct ufs_hba *hba, struct ufs_hw_queue *hwq)
+{
+ void __iomem *reg;
+ u32 id = hwq->id, val;
+ int err;
+
+ writel(SQ_STOP, mcq_opr_base(hba, OPR_SQD, id) + REG_SQRTC);
+ reg = mcq_opr_base(hba, OPR_SQD, id) + REG_SQRTS;
+ err = read_poll_timeout(readl, val, val & SQ_STS, 20,
+ MCQ_POLL_US, false, reg);
+ if (err)
+ dev_err(hba->dev, "%s: failed. hwq-id=%d, err=%d\n",
+ __func__, id, err);
+ return err;
+}
+
+static int ufshcd_mcq_sq_start(struct ufs_hba *hba, struct ufs_hw_queue *hwq)
+{
+ void __iomem *reg;
+ u32 id = hwq->id, val;
+ int err;
+
+ writel(SQ_START, mcq_opr_base(hba, OPR_SQD, id) + REG_SQRTC);
+ reg = mcq_opr_base(hba, OPR_SQD, id) + REG_SQRTS;
+ err = read_poll_timeout(readl, val, !(val & SQ_STS), 20,
+ MCQ_POLL_US, false, reg);
+ if (err)
+ dev_err(hba->dev, "%s: failed. hwq-id=%d, err=%d\n",
+ __func__, id, 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.
+ *
+ * Returns 0 for success; error code otherwise.
+ */
+int ufshcd_mcq_sq_cleanup(struct ufs_hba *hba, int task_tag)
+{
+ 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, id, val;
+ int err;
+
+ if (task_tag != hba->nutrs - UFSHCD_NUM_RESERVED) {
+ if (!cmd)
+ return -EINVAL;
+ hwq = ufshcd_mcq_req_to_hwq(hba, scsi_cmd_to_rq(cmd));
+ } else {
+ hwq = hba->dev_cmd_queue;
+ }
+
+ id = hwq->id;
+
+ mutex_lock(&hwq->sq_mutex);
+
+ /* 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, id);
+ 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 = read_poll_timeout(readl, val, val & SQ_CUS, 20,
+ MCQ_POLL_US, false, reg);
+ if (err)
+ dev_err(hba->dev, "%s: failed. hwq=%d, tag=%d err=%ld\n",
+ __func__, id, task_tag,
+ FIELD_GET(SQ_ICU_ERR_CODE_MASK, readl(reg)));
+
+ if (ufshcd_mcq_sq_start(hba, hwq))
+ err = -ETIMEDOUT;
+
+unlock:
+ mutex_unlock(&hwq->sq_mutex);
+ return err;
+}
+
+/**
+ * ufshcd_mcq_nullify_sqe - Nullify the submission queue entry.
+ * Write the sqe's Command Type to 0xF. The host controller will not
+ * fetch any sqe with Command Type = 0xF.
+ *
+ * @utrd - UTP Transfer Request Descriptor to be nullified.
+ */
+static void ufshcd_mcq_nullify_sqe(struct utp_transfer_req_desc *utrd)
+{
+ u32 dword_0;
+
+ 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 command in the submission queue
+ * If the command is in the submission queue and not issued to the device yet,
+ * nullify the sqe so the host controller will skip fetching the sqe.
+ *
+ * @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 ufshcd_lrb *lrbp = &hba->lrb[task_tag];
+ struct utp_transfer_req_desc *utrd;
+ u32 mask = hwq->max_entries - 1;
+ __le64 cmd_desc_base_addr;
+ bool ret = false;
+ u64 addr, match;
+ u32 sq_head_slot;
+
+ mutex_lock(&hwq->sq_mutex);
+
+ ufshcd_mcq_sq_stop(hba, hwq);
+ sq_head_slot = ufshcd_mcq_get_sq_head_slot(hwq);
+ if (sq_head_slot == hwq->sq_tail_slot)
+ goto out;
+
+ cmd_desc_base_addr = lrbp->utr_descriptor_ptr->command_desc_base_addr;
+ addr = le64_to_cpu(cmd_desc_base_addr) & CQE_UCD_BA;
+
+ while (sq_head_slot != hwq->sq_tail_slot) {
+ utrd = hwq->sqe_base_addr +
+ sq_head_slot * sizeof(struct utp_transfer_req_desc);
+ match = le64_to_cpu(utrd->command_desc_base_addr) & CQE_UCD_BA;
+ if (addr == match) {
+ ufshcd_mcq_nullify_sqe(utrd);
+ ret = true;
+ goto out;
+ }
+ sq_head_slot = (sq_head_slot + 1) & mask;
+ }
+
+out:
+ ufshcd_mcq_sq_start(hba, hwq);
+ mutex_unlock(&hwq->sq_mutex);
+ return ret;
+}
diff --git a/drivers/ufs/core/ufshcd-priv.h b/drivers/ufs/core/ufshcd-priv.h
index d53b93c2..40727e8 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);
+
#define UFSHCD_MCQ_IO_QUEUE_OFFSET 1
#define SD_ASCII_STD true
#define SD_RAW false
@@ -404,4 +406,12 @@ static inline struct cq_entry *ufshcd_mcq_cur_cqe(struct ufs_hw_queue *q)

return cqe + q->cq_head_slot;
}
+
+static inline u32 ufshcd_mcq_get_sq_head_slot(struct ufs_hw_queue *q)
+{
+ u32 val = readl(q->mcq_sq_head);
+
+ return val / sizeof(struct utp_transfer_req_desc);
+}
+
#endif /* _UFSHCD_PRIV_H_ */
diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index a37e1eb..140ab15 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -173,7 +173,6 @@ EXPORT_SYMBOL_GPL(ufshcd_dump_regs);
enum {
UFSHCD_MAX_CHANNEL = 0,
UFSHCD_MAX_ID = 1,
- UFSHCD_NUM_RESERVED = 1,
UFSHCD_CMD_PER_LUN = 32 - UFSHCD_NUM_RESERVED,
UFSHCD_CAN_QUEUE = 32 - UFSHCD_NUM_RESERVED,
};
diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 721ae4c..3c9ecda 100644
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -1088,6 +1088,7 @@ struct ufs_hba {
* @cq_tail_slot: current slot to which CQ tail pointer is pointing
* @cq_head_slot: current slot to which CQ head pointer is pointing
* @cq_lock: Synchronize between multiple polling instances
+ * @sq_mutex: prevent submission queue concurrent access
*/
struct ufs_hw_queue {
void __iomem *mcq_sq_head;
@@ -1106,6 +1107,8 @@ struct ufs_hw_queue {
u32 cq_tail_slot;
u32 cq_head_slot;
spinlock_t cq_lock;
+ /* prevent concurrent access to submission queue */
+ struct mutex sq_mutex;
};

static inline bool is_mcq_enabled(struct ufs_hba *hba)
diff --git a/include/ufs/ufshci.h b/include/ufs/ufshci.h
index 7c5a76b..9d291ca 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 {
@@ -111,12 +114,26 @@ 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 */
#define MINOR_VERSION_NUM_MASK UFS_MASK(0xFFFF, 0)
#define MAJOR_VERSION_NUM_MASK UFS_MASK(0xFFFF, 16)

+#define UFSHCD_NUM_RESERVED 1
/*
* Controller UFSHCI version
* - 2.x and newer use the following scheme:
--
2.7.4