2023-03-29 10:14:37

by Bao D. Nguyen

[permalink] [raw]
Subject: [PATCH v1 1/5] ufs: mcq: Add supporting functions for mcq abort

Add supporting functions to handle ufs abort in mcq mode.

Signed-off-by: Bao D. Nguyen <[email protected]>
---
drivers/ufs/core/ufs-mcq.c | 174 +++++++++++++++++++++++++++++++++++++++++
drivers/ufs/core/ufshcd-priv.h | 10 +++
drivers/ufs/core/ufshcd.c | 2 -
include/ufs/ufshci.h | 17 ++++
4 files changed, 201 insertions(+), 2 deletions(-)

diff --git a/drivers/ufs/core/ufs-mcq.c b/drivers/ufs/core/ufs-mcq.c
index 31df052..6f6b22c 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 micro second unit */
+#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,
@@ -429,3 +436,170 @@ 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 i = hwq->id, val;
+ 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 = 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__, 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, val;
+ 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 = 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__, 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, val;
+ int err;
+
+ if (task_tag != hba->nutrs - UFSHCD_NUM_RESERVED) {
+ if (!cmd)
+ return FAILED;
+ hwq = ufshcd_mcq_req_to_hwq(hba, scsi_cmd_to_rq(cmd));
+ } else {
+ hwq = hba->dev_cmd_queue;
+ }
+
+ 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 = read_poll_timeout(readl, val, val & SQ_CUS, 20,
+ MCQ_POLL_US, false, reg);
+ 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));
+
+ if (ufshcd_mcq_sq_start(hba, hwq))
+ err = FAILED;
+
+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 sq_head_slot;
+
+ spin_lock(&hwq->sq_lock);
+
+ 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;
+
+ addr = ufshcd_mcq_get_cmd_desc_addr(hba, task_tag);
+ while (sq_head_slot != hwq->sq_tail_slot) {
+ utrd = (struct utp_transfer_req_desc *)(hwq->sqe_base_addr +
+ sq_head_slot * 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;
+ }
+ sq_head_slot = (sq_head_slot + 1) & mask;
+ }
+
+out:
+ ufshcd_mcq_sq_start(hba, hwq);
+ 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..1a40cf7 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 +405,12 @@ 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 35a3bd9..808387c 100644
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -56,7 +56,6 @@
#define NOP_OUT_RETRIES 10
/* Timeout after 50 msecs if NOP OUT hangs without response */
#define NOP_OUT_TIMEOUT 50 /* msecs */
-
/* Query request retries */
#define QUERY_REQ_RETRIES 3
/* Query request timeout */
@@ -173,7 +172,6 @@ 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/ufshci.h b/include/ufs/ufshci.h
index 11424bb..ceb8664 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


2023-04-11 13:16:02

by Po-Wen Kao

[permalink] [raw]
Subject: Re: [PATCH v1 1/5] ufs: mcq: Add supporting functions for mcq abort

Hi Bao D.,

We have done some test based on your RFC v3 patches and an issue is
reported.

kworker/u16:4: BUG: scheduling while atomic:
kworker/u16:4/5736/0x00000002
kworker/u16:4: [name:core&]Preemption disabled at:
kworker/u16:4: [<ffffffef97e33024>] ufshcd_mcq_sq_cleanup+0x9c/0x27c
kworker/u16:4: CPU: 2 PID: 5736 Comm: kworker/u16:4 Tainted: G
S W OE
kworker/u16:4: Workqueue: ufs_eh_wq_0 ufshcd_err_handler
kworker/u16:4: Call trace:
kworker/u16:4: dump_backtrace+0x108/0x15c
kworker/u16:4: show_stack+0x20/0x30
kworker/u16:4: dump_stack_lvl+0x6c/0x8c
kworker/u16:4: dump_stack+0x20/0x44
kworker/u16:4: __schedule_bug+0xd4/0x100
kworker/u16:4: __schedule+0x660/0xa5c
kworker/u16:4: schedule+0x80/0xec
kworker/u16:4: schedule_hrtimeout_range_clock+0xa0/0x140
kworker/u16:4: schedule_hrtimeout_range+0x1c/0x30
kworker/u16:4: usleep_range_state+0x88/0xd8
kworker/u16:4: ufshcd_mcq_sq_cleanup+0x170/0x27c
kworker/u16:4: ufshcd_clear_cmds+0x78/0x184
kworker/u16:4: ufshcd_wait_for_dev_cmd+0x234/0x348
kworker/u16:4: ufshcd_exec_dev_cmd+0x220/0x298
kworker/u16:4: ufshcd_verify_dev_init+0x68/0x124
kworker/u16:4: ufshcd_probe_hba+0x390/0x9bc
kworker/u16:4: ufshcd_host_reset_and_restore+0x74/0x158
kworker/u16:4: ufshcd_reset_and_restore+0x70/0x31c
kworker/u16:4: ufshcd_err_handler+0xad4/0xe58
kworker/u16:4: process_one_work+0x214/0x5b8
kworker/u16:4: worker_thread+0x2d4/0x448
kworker/u16:4: kthread+0x110/0x1e0
kworker/u16:4: ret_from_fork+0x10/0x20
kworker/u16:4: ------------[ cut here ]------------


On Wed, 2023-03-29 at 03:01 -0700, Bao D. Nguyen wrote:

> +/**
> + * 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, val;
> + int err;
> +
> + if (task_tag != hba->nutrs - UFSHCD_NUM_RESERVED) {
> + if (!cmd)
> + return FAILED;
> + hwq = ufshcd_mcq_req_to_hwq(hba,
> scsi_cmd_to_rq(cmd));
> + } else {
> + hwq = hba->dev_cmd_queue;
> + }
> +
> + i = hwq->id;
> +
> + spin_lock(&hwq->sq_lock);

As spin_lock() disable preemption

> +
> + /* 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 = read_poll_timeout(readl, val, val & SQ_CUS, 20,
> + MCQ_POLL_US, false, reg);

read_poll_timeout() was ufshcd_mcq_poll_register() in last patch,
right? ufshcd_mcq_poll_register() calls usleep_range() causing KE as
reported above. Same issue seems to still exist as read_poll_timeout()
sleeps.

Skipping ufshcd_mcq_sq_cleanup() by returning FAILED directly to
trigger reset in ufshcd error handler successfully recover host.

BTW, is there maybe a change list between RFC v3 and this v1 patch? :)
Thanks

Po-Wen


2023-04-13 06:13:43

by Bao D. Nguyen

[permalink] [raw]
Subject: Re: [PATCH v1 1/5] ufs: mcq: Add supporting functions for mcq abort

On 4/11/2023 6:14 AM, Powen Kao (高伯文) wrote:
> Hi Bao D.,
>
> We have done some test based on your RFC v3 patches and an issue is
> reported.

Hi Powen,

Thank you very much for catching this issue. It seems that I cannot use
read_poll_timeout() because it sleeps while holding the spin_lock().

I will make the change to poll the registers in a tight loop with
udelay(20) polling interval in the next revision.

Thanks,
Bao

>
> kworker/u16:4: BUG: scheduling while atomic:
> kworker/u16:4/5736/0x00000002
> kworker/u16:4: [name:core&]Preemption disabled at:
> kworker/u16:4: [<ffffffef97e33024>] ufshcd_mcq_sq_cleanup+0x9c/0x27c
> kworker/u16:4: CPU: 2 PID: 5736 Comm: kworker/u16:4 Tainted: G
> S W OE
> kworker/u16:4: Workqueue: ufs_eh_wq_0 ufshcd_err_handler
> kworker/u16:4: Call trace:
> kworker/u16:4: dump_backtrace+0x108/0x15c
> kworker/u16:4: show_stack+0x20/0x30
> kworker/u16:4: dump_stack_lvl+0x6c/0x8c
> kworker/u16:4: dump_stack+0x20/0x44
> kworker/u16:4: __schedule_bug+0xd4/0x100
> kworker/u16:4: __schedule+0x660/0xa5c
> kworker/u16:4: schedule+0x80/0xec
> kworker/u16:4: schedule_hrtimeout_range_clock+0xa0/0x140
> kworker/u16:4: schedule_hrtimeout_range+0x1c/0x30
> kworker/u16:4: usleep_range_state+0x88/0xd8
> kworker/u16:4: ufshcd_mcq_sq_cleanup+0x170/0x27c
> kworker/u16:4: ufshcd_clear_cmds+0x78/0x184
> kworker/u16:4: ufshcd_wait_for_dev_cmd+0x234/0x348
> kworker/u16:4: ufshcd_exec_dev_cmd+0x220/0x298
> kworker/u16:4: ufshcd_verify_dev_init+0x68/0x124
> kworker/u16:4: ufshcd_probe_hba+0x390/0x9bc
> kworker/u16:4: ufshcd_host_reset_and_restore+0x74/0x158
> kworker/u16:4: ufshcd_reset_and_restore+0x70/0x31c
> kworker/u16:4: ufshcd_err_handler+0xad4/0xe58
> kworker/u16:4: process_one_work+0x214/0x5b8
> kworker/u16:4: worker_thread+0x2d4/0x448
> kworker/u16:4: kthread+0x110/0x1e0
> kworker/u16:4: ret_from_fork+0x10/0x20
> kworker/u16:4: ------------[ cut here ]------------
>
>
> On Wed, 2023-03-29 at 03:01 -0700, Bao D. Nguyen wrote:
>
>> +/**
>> + * 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, val;
>> + int err;
>> +
>> + if (task_tag != hba->nutrs - UFSHCD_NUM_RESERVED) {
>> + if (!cmd)
>> + return FAILED;
>> + hwq = ufshcd_mcq_req_to_hwq(hba,
>> scsi_cmd_to_rq(cmd));
>> + } else {
>> + hwq = hba->dev_cmd_queue;
>> + }
>> +
>> + i = hwq->id;
>> +
>> + spin_lock(&hwq->sq_lock);
> As spin_lock() disable preemption
>
>> +
>> + /* 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 = read_poll_timeout(readl, val, val & SQ_CUS, 20,
>> + MCQ_POLL_US, false, reg);
> read_poll_timeout() was ufshcd_mcq_poll_register() in last patch,
> right? ufshcd_mcq_poll_register() calls usleep_range() causing KE as
> reported above. Same issue seems to still exist as read_poll_timeout()
> sleeps.
>
> Skipping ufshcd_mcq_sq_cleanup() by returning FAILED directly to
> trigger reset in ufshcd error handler successfully recover host.
>
> BTW, is there maybe a change list between RFC v3 and this v1 patch? :)
> Thanks
>
> Po-Wen
>
>