scsi: ufs: core: Use local_clock() for debugging timestamps

CLOCK_MONOTONIC is not advanced when the system is in suspend. This becomes
problematic when debugging issues related to suspend-resume: the timestamps
printed by ufshcd_print_trs can not be correlated with dmesg entries, which
are timestamped with local_clock().

Change the used clock to local_clock() for the informational timestamp
variables and adds mirroring *_local_clock instances for variables used in
subsequent derevations (to not change the semantics of those derevations).

Link: https://lore.kernel.org/r/20220804065019.v5.1.I699244ea7efbd326a34a6dfd9b5a31e78400cf68@changeid
Acked-by: Stanley Chu <stanley.chu@mediatek.com>
Acked-by: Avri Altman <avri.altman@wdc.com>
Signed-off-by: Daniil Lunev <dlunev@chromium.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/ufs/core/ufshcd.c b/drivers/ufs/core/ufshcd.c
index 6bc679d..0391b66 100644 (file)
--- a/drivers/ufs/core/ufshcd.c
+++ b/drivers/ufs/core/ufshcd.c
@@ -21,6 +21,7 @@
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/regulator/consumer.h>
+#include <linux/sched/clock.h>
 #include <scsi/scsi_cmnd.h>
 #include <scsi/scsi_dbg.h>
 #include <scsi/scsi_driver.h>
@@ -457,7 +458,7 @@ static void ufshcd_print_evt(struct ufs_hba *hba, u32 id,
                if (e->tstamp[p] == 0)
                        continue;
                dev_err(hba->dev, "%s[%d] = 0x%x at %lld us\n", err_name, p,
-                       e->val[p], ktime_to_us(e->tstamp[p]));
+                       e->val[p], div_u64(e->tstamp[p], 1000));
                found = true;
        }
 
@@ -502,9 +503,9 @@ void ufshcd_print_trs(struct ufs_hba *hba, unsigned long bitmap, bool pr_prdt)
                lrbp = &hba->lrb[tag];
 
                dev_err(hba->dev, "UPIU[%d] - issue time %lld us\n",
-                               tag, ktime_to_us(lrbp->issue_time_stamp));
+                               tag, div_u64(lrbp->issue_time_stamp_local_clock, 1000));
                dev_err(hba->dev, "UPIU[%d] - complete time %lld us\n",
-                               tag, ktime_to_us(lrbp->compl_time_stamp));
+                               tag, div_u64(lrbp->compl_time_stamp_local_clock, 1000));
                dev_err(hba->dev,
                        "UPIU[%d] - Transfer Request Descriptor phys@0x%llx\n",
                        tag, (u64)lrbp->utrd_dma_addr);
@@ -566,10 +567,10 @@ static void ufshcd_print_host_state(struct ufs_hba *hba)
        dev_err(hba->dev, "Clk gate=%d\n", hba->clk_gating.state);
        dev_err(hba->dev,
                "last_hibern8_exit_tstamp at %lld us, hibern8_exit_cnt=%d\n",
-               ktime_to_us(hba->ufs_stats.last_hibern8_exit_tstamp),
+               div_u64(hba->ufs_stats.last_hibern8_exit_tstamp, 1000),
                hba->ufs_stats.hibern8_exit_cnt);
        dev_err(hba->dev, "last intr at %lld us, last intr status=0x%x\n",
-               ktime_to_us(hba->ufs_stats.last_intr_ts),
+               div_u64(hba->ufs_stats.last_intr_ts, 1000),
                hba->ufs_stats.last_intr_status);
        dev_err(hba->dev, "error handling flags=0x%x, req. abort count=%d\n",
                hba->eh_flags, hba->req_abort_count);
@@ -2140,7 +2141,9 @@ void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
        unsigned long flags;
 
        lrbp->issue_time_stamp = ktime_get();
+       lrbp->issue_time_stamp_local_clock = local_clock();
        lrbp->compl_time_stamp = ktime_set(0, 0);
+       lrbp->compl_time_stamp_local_clock = 0;
        ufshcd_add_command_trace(hba, task_tag, UFS_CMD_SEND);
        ufshcd_clk_scaling_start_busy(hba);
        if (unlikely(ufshcd_should_inform_monitor(hba, lrbp)))
@@ -4222,7 +4225,7 @@ int ufshcd_uic_hibern8_exit(struct ufs_hba *hba)
        } else {
                ufshcd_vops_hibern8_notify(hba, UIC_CMD_DME_HIBER_EXIT,
                                                                POST_CHANGE);
-               hba->ufs_stats.last_hibern8_exit_tstamp = ktime_get();
+               hba->ufs_stats.last_hibern8_exit_tstamp = local_clock();
                hba->ufs_stats.hibern8_exit_cnt++;
        }
 
@@ -4724,7 +4727,7 @@ void ufshcd_update_evt_hist(struct ufs_hba *hba, u32 id, u32 val)
 
        e = &hba->ufs_stats.event[id];
        e->val[e->pos] = val;
-       e->tstamp[e->pos] = ktime_get();
+       e->tstamp[e->pos] = local_clock();
        e->cnt += 1;
        e->pos = (e->pos + 1) % UFS_EVENT_HIST_LENGTH;
 
@@ -5357,6 +5360,7 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
        for_each_set_bit(index, &completed_reqs, hba->nutrs) {
                lrbp = &hba->lrb[index];
                lrbp->compl_time_stamp = ktime_get();
+               lrbp->compl_time_stamp_local_clock = local_clock();
                cmd = lrbp->cmd;
                if (cmd) {
                        if (unlikely(ufshcd_should_inform_monitor(hba, lrbp)))
@@ -6645,7 +6649,7 @@ static irqreturn_t ufshcd_intr(int irq, void *__hba)
 
        intr_status = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
        hba->ufs_stats.last_intr_status = intr_status;
-       hba->ufs_stats.last_intr_ts = ktime_get();
+       hba->ufs_stats.last_intr_ts = local_clock();
 
        /*
         * There could be max of hba->nutrs reqs in flight and in worst case

diff --git a/include/ufs/ufshcd.h b/include/ufs/ufshcd.h
index 7fe1a92..d81e9a5 100644 (file)
--- a/include/ufs/ufshcd.h
+++ b/include/ufs/ufshcd.h
@@ -160,8 +160,10 @@ struct ufs_pm_lvl_states {
  * @task_tag: Task tag of the command
  * @lun: LUN of the command
  * @intr_cmd: Interrupt command (doesn't participate in interrupt aggregation)
- * @issue_time_stamp: time stamp for debug purposes
- * @compl_time_stamp: time stamp for statistics
+ * @issue_time_stamp: time stamp for debug purposes (CLOCK_MONOTONIC)
+ * @issue_time_stamp_local_clock: time stamp for debug purposes (local_clock)
+ * @compl_time_stamp: time stamp for statistics (CLOCK_MONOTONIC)
+ * @compl_time_stamp_local_clock: time stamp for debug purposes (local_clock)
  * @crypto_key_slot: the key slot to use for inline crypto (-1 if none)
  * @data_unit_num: the data unit number for the first block for inline crypto
  * @req_abort_skip: skip request abort task flag
@@ -185,7 +187,9 @@ struct ufshcd_lrb {
        u8 lun; /* UPIU LUN id field is only 8-bit wide */
        bool intr_cmd;
        ktime_t issue_time_stamp;
+       u64 issue_time_stamp_local_clock;
        ktime_t compl_time_stamp;
+       u64 compl_time_stamp_local_clock;
 #ifdef CONFIG_SCSI_UFS_CRYPTO
        int crypto_key_slot;
        u64 data_unit_num;
@@ -430,7 +434,7 @@ struct ufs_clk_scaling {
 struct ufs_event_hist {
        int pos;
        u32 val[UFS_EVENT_HIST_LENGTH];
-       ktime_t tstamp[UFS_EVENT_HIST_LENGTH];
+       u64 tstamp[UFS_EVENT_HIST_LENGTH];
        unsigned long long cnt;
 };
 
@@ -446,10 +450,10 @@ struct ufs_event_hist {
  */
 struct ufs_stats {
        u32 last_intr_status;
-       ktime_t last_intr_ts;
+       u64 last_intr_ts;
 
        u32 hibern8_exit_cnt;
-       ktime_t last_hibern8_exit_tstamp;
+       u64 last_hibern8_exit_tstamp;
        struct ufs_event_hist event[UFS_EVT_CNT];
 };