scsi: ufs: add trace event for ufs commands

Use the ftrace infrastructure to conditionally trace ufs command events.
New trace event is created, which samples the following ufs command data:
- device name
- optional identification string
- task tag
- doorbell register
- number of transfer bytes
- interrupt status register
- request start LBA
- command opcode

Currently we only fully trace read(10) and write(10) commands.
All other commands which pass through ufshcd_send_command() will be
printed with "-1" in the lba and transfer_len fields.

Usage:
	echo 1 > /sys/kernel/debug/tracing/events/ufs/enable
	cat /sys/kernel/debug/tracing/trace_pipe

Signed-off-by: Lee Susman <lsusman@codeaurora.org>
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 58c4df4..2c88757 100644 (file)
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -293,6 +293,41 @@ static inline void ufshcd_remove_non_printable(char *val)
                *val = ' ';
 }
 
+static void ufshcd_add_command_trace(struct ufs_hba *hba,
+               unsigned int tag, const char *str)
+{
+       sector_t lba = -1;
+       u8 opcode = 0;
+       u32 intr, doorbell;
+       struct ufshcd_lrb *lrbp;
+       int transfer_len = -1;
+
+       if (!trace_ufshcd_command_enabled())
+               return;
+
+       lrbp = &hba->lrb[tag];
+
+       if (lrbp->cmd) { /* data phase exists */
+               opcode = (u8)(*lrbp->cmd->cmnd);
+               if ((opcode == READ_10) || (opcode == WRITE_10)) {
+                       /*
+                        * Currently we only fully trace read(10) and write(10)
+                        * commands
+                        */
+                       if (lrbp->cmd->request && lrbp->cmd->request->bio)
+                               lba =
+                                 lrbp->cmd->request->bio->bi_iter.bi_sector;
+                       transfer_len = be32_to_cpu(
+                               lrbp->ucd_req_ptr->sc.exp_data_transfer_len);
+               }
+       }
+
+       intr = ufshcd_readl(hba, REG_INTERRUPT_STATUS);
+       doorbell = ufshcd_readl(hba, REG_UTP_TRANSFER_REQ_DOOR_BELL);
+       trace_ufshcd_command(dev_name(hba->dev), str, tag,
+                               doorbell, transfer_len, intr, lba, opcode);
+}
+
 static void ufshcd_print_host_regs(struct ufs_hba *hba)
 {
        /*
@@ -1166,6 +1201,7 @@ void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
        ufshcd_writel(hba, 1 << task_tag, REG_UTP_TRANSFER_REQ_DOOR_BELL);
        /* Make sure that doorbell is committed immediately */
        wmb();
+       ufshcd_add_command_trace(hba, task_tag, "send");
 }
 
 /**
@@ -3955,6 +3991,7 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
                lrbp = &hba->lrb[index];
                cmd = lrbp->cmd;
                if (cmd) {
+                       ufshcd_add_command_trace(hba, index, "complete");
                        result = ufshcd_transfer_rsp_status(hba, lrbp);
                        scsi_dma_unmap(cmd);
                        cmd->result = result;
@@ -3966,8 +4003,11 @@ static void __ufshcd_transfer_req_compl(struct ufs_hba *hba,
                        __ufshcd_release(hba);
                } else if (lrbp->command_type == UTP_CMD_TYPE_DEV_MANAGE ||
                        lrbp->command_type == UTP_CMD_TYPE_UFS_STORAGE) {
-                       if (hba->dev_cmd.complete)
+                       if (hba->dev_cmd.complete) {
+                               ufshcd_add_command_trace(hba, index,
+                                               "dev_complete");
                                complete(hba->dev_cmd.complete);
+                       }
                }
        }
 

diff --git a/include/trace/events/ufs.h b/include/trace/events/ufs.h
index e9634df..bf6f826 100644 (file)
--- a/include/trace/events/ufs.h
+++ b/include/trace/events/ufs.h
@@ -219,6 +219,44 @@ DEFINE_EVENT(ufshcd_template, ufshcd_init,
             TP_PROTO(const char *dev_name, int err, s64 usecs,
                      int dev_state, int link_state),
             TP_ARGS(dev_name, err, usecs, dev_state, link_state));
+
+TRACE_EVENT(ufshcd_command,
+       TP_PROTO(const char *dev_name, const char *str, unsigned int tag,
+                       u32 doorbell, int transfer_len, u32 intr, u64 lba,
+                       u8 opcode),
+
+       TP_ARGS(dev_name, str, tag, doorbell, transfer_len, intr, lba, opcode),
+
+       TP_STRUCT__entry(
+               __string(dev_name, dev_name)
+               __string(str, str)
+               __field(unsigned int, tag)
+               __field(u32, doorbell)
+               __field(int, transfer_len)
+               __field(u32, intr)
+               __field(u64, lba)
+               __field(u8, opcode)
+       ),
+
+       TP_fast_assign(
+               __assign_str(dev_name, dev_name);
+               __assign_str(str, str);
+               __entry->tag = tag;
+               __entry->doorbell = doorbell;
+               __entry->transfer_len = transfer_len;
+               __entry->intr = intr;
+               __entry->lba = lba;
+               __entry->opcode = opcode;
+       ),
+
+       TP_printk(
+               "%s: %s: tag: %u, DB: 0x%x, size: %d, IS: %u, LBA: %llu, opcode: 0x%x",
+               __get_str(str), __get_str(dev_name), __entry->tag,
+               __entry->doorbell, __entry->transfer_len,
+               __entry->intr, __entry->lba, (u32)__entry->opcode
+       )
+);
+
 #endif /* if !defined(_TRACE_UFS_H) || defined(TRACE_HEADER_MULTI_READ) */
 
 /* This part must be outside protection */