scsi: ufs-debug: add debugfs capability to collect query statistics

This patch adds a new debugfs capability to collect query statistics.
It counts how many times each IDN (index) was sent to device for each
query opcode.

A usage example:
1. to clean current query statistics:
   echo 1 > /d/ufshcd0/stats/query_stats

2. to dump the current query statistics:
   cat /d/ufshcd0/stats/query_stats

This capability is always on, and can not be turned off.

Change-Id: I46ec405aae480c0dc161dca015b407bde6335cf7
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>

4 files changed, 104 insertions, 1 deletions

diff --git a/drivers/scsi/ufs/ufs-debugfs.c b/drivers/scsi/ufs/ufs-debugfs.c
index 03cda3099673..bdb12352e8c4 100644
--- a/drivers/scsi/ufs/ufs-debugfs.c
+++ b/drivers/scsi/ufs/ufs-debugfs.c
@@ -678,6 +678,77 @@ static const struct file_operations ufsdbg_tag_stats_fops = {
 	.write		= ufsdbg_tag_stats_write,
 };
 
+static int ufsdbg_query_stats_show(struct seq_file *file, void *data)
+{
+	struct ufs_hba *hba = (struct ufs_hba *)file->private;
+	struct ufs_stats *ufs_stats = &hba->ufs_stats;
+	int i, j;
+	static const char *opcode_name[UPIU_QUERY_OPCODE_MAX] = {
+		"QUERY_OPCODE_NOP:",
+		"QUERY_OPCODE_READ_DESC:",
+		"QUERY_OPCODE_WRITE_DESC:",
+		"QUERY_OPCODE_READ_ATTR:",
+		"QUERY_OPCODE_WRITE_ATTR:",
+		"QUERY_OPCODE_READ_FLAG:",
+		"QUERY_OPCODE_SET_FLAG:",
+		"QUERY_OPCODE_CLEAR_FLAG:",
+		"QUERY_OPCODE_TOGGLE_FLAG:",
+	};
+
+	seq_puts(file, "\n");
+	seq_puts(file, "The following table shows how many TIMES each IDN was sent to device for each QUERY OPCODE:\n");
+	seq_puts(file, "\n");
+
+	for (i = 0; i < UPIU_QUERY_OPCODE_MAX; i++) {
+		seq_printf(file, "%-30s", opcode_name[i]);
+
+		for (j = 0; j < MAX_QUERY_IDN; j++) {
+			/*
+			 * we would like to print only the non-zero data,
+			 * (non-zero number of times that IDN was sent
+			 * to the device per opcode). There is no
+			 * importance to the "table structure" of the output.
+			 */
+			if (ufs_stats->query_stats_arr[i][j])
+				seq_printf(file, "IDN 0x%02X: %d,\t", j,
+					   ufs_stats->query_stats_arr[i][j]);
+		}
+		seq_puts(file, "\n");
+	}
+
+	return 0;
+}
+
+static int ufsdbg_query_stats_open(struct inode *inode, struct file *file)
+{
+	return single_open(file, ufsdbg_query_stats_show, inode->i_private);
+}
+
+static ssize_t ufsdbg_query_stats_write(struct file *filp,
+				      const char __user *ubuf, size_t cnt,
+				       loff_t *ppos)
+{
+	struct ufs_hba *hba = filp->f_mapping->host->i_private;
+	struct ufs_stats *ufs_stats = &hba->ufs_stats;
+	int i, j;
+
+	mutex_lock(&hba->dev_cmd.lock);
+
+	for (i = 0; i < UPIU_QUERY_OPCODE_MAX; i++)
+		for (j = 0; j < MAX_QUERY_IDN; j++)
+			ufs_stats->query_stats_arr[i][j] = 0;
+
+	mutex_unlock(&hba->dev_cmd.lock);
+
+	return cnt;
+}
+
+static const struct file_operations ufsdbg_query_stats_fops = {
+	.open		= ufsdbg_query_stats_open,
+	.read		= seq_read,
+	.write		= ufsdbg_query_stats_write,
+};
+
 static int ufsdbg_err_stats_show(struct seq_file *file, void *data)
 {
 	struct ufs_hba *hba = (struct ufs_hba *)file->private;
@@ -1482,6 +1553,16 @@ void ufsdbg_add_debugfs(struct ufs_hba *hba)
 		goto err;
 	}
 
+	hba->debugfs_files.query_stats =
+		debugfs_create_file("query_stats", S_IRUSR | S_IWUSR,
+					   hba->debugfs_files.stats_folder, hba,
+					   &ufsdbg_query_stats_fops);
+	if (!hba->debugfs_files.query_stats) {
+		dev_err(hba->dev, "%s:  NULL query_stats file, exiting",
+			__func__);
+		goto err;
+	}
+
 	hba->debugfs_files.err_stats =
 		debugfs_create_file("err_stats", S_IRUSR | S_IWUSR,
 					   hba->debugfs_files.stats_folder, hba,
diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index cc567cd7572e..423d32e66835 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -136,6 +136,13 @@ static void update_req_stats(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 			hba->ufs_stats.req_stats[rq_type].min = delta;
 }
 
+static void
+ufshcd_update_query_stats(struct ufs_hba *hba, enum query_opcode opcode, u8 idn)
+{
+	if (opcode < UPIU_QUERY_OPCODE_MAX && idn < MAX_QUERY_IDN)
+		hba->ufs_stats.query_stats_arr[opcode][idn]++;
+}
+
 #else
 static inline void ufshcd_update_tag_stats(struct ufs_hba *hba, int tag)
 {
@@ -154,6 +161,12 @@ static inline
 void update_req_stats(struct ufs_hba *hba, struct ufshcd_lrb *lrbp)
 {
 }
+
+static inline
+void ufshcd_update_query_stats(struct ufs_hba *hba,
+			       enum query_opcode opcode, u8 idn)
+{
+}
 #endif
 
 #define UFSHCD_REQ_SENSE_SIZE	18
@@ -2835,6 +2848,8 @@ static inline void ufshcd_init_query(struct ufs_hba *hba,
 	(*request)->upiu_req.idn = idn;
 	(*request)->upiu_req.index = index;
 	(*request)->upiu_req.selector = selector;
+
+	ufshcd_update_query_stats(hba, opcode, idn);
 }
 
 static int ufshcd_query_flag_retry(struct ufs_hba *hba,
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index e0a62791c0dd..ad454a3cc16e 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -475,6 +475,7 @@ struct debugfs_files {
 	struct dentry *dme_peer_read;
 	struct dentry *dbg_print_en;
 	struct dentry *req_stats;
+	struct dentry *query_stats;
 	u32 dme_local_attr_id;
 	u32 dme_peer_attr_id;
 	struct dentry *reset_controller;
@@ -521,7 +522,8 @@ struct ufshcd_req_stat {
  * @tag_stats: pointer to tag statistic counters
  * @q_depth: current amount of busy slots
  * @err_stats: counters to keep track of various errors
- * @req_stat: request handling time statistics per request type
+ * @req_stats: request handling time statistics per request type
+ * @query_stats_arr: array that holds query statistics
  * @hibern8_exit_cnt: Counter to keep track of number of exits,
  *		reset this after link-startup.
  * @last_hibern8_exit_tstamp: Set time after the hibern8 exit.
@@ -539,6 +541,8 @@ struct ufs_stats {
 	int q_depth;
 	int err_stats[UFS_ERR_MAX];
 	struct ufshcd_req_stat req_stats[TS_NUM_STATS];
+	int query_stats_arr[UPIU_QUERY_OPCODE_MAX][MAX_QUERY_IDN];
+
 #endif
 	u32 hibern8_exit_cnt;
 	ktime_t last_hibern8_exit_tstamp;
diff --git a/include/uapi/scsi/ufs/ufs.h b/include/uapi/scsi/ufs/ufs.h
index 894ea453737f..4b9a0049639d 100644
--- a/include/uapi/scsi/ufs/ufs.h
+++ b/include/uapi/scsi/ufs/ufs.h
@@ -1,6 +1,8 @@
 #ifndef UAPI_UFS_H_
 #define UAPI_UFS_H_
 
+#define MAX_QUERY_IDN	0x12
+
 /* Flag idn for Query Requests*/
 enum flag_idn {
 	QUERY_FLAG_IDN_FDEVICEINIT		= 0x01,
@@ -62,5 +64,6 @@ enum query_opcode {
 	UPIU_QUERY_OPCODE_SET_FLAG	= 0x6,
 	UPIU_QUERY_OPCODE_CLEAR_FLAG	= 0x7,
 	UPIU_QUERY_OPCODE_TOGGLE_FLAG	= 0x8,
+	UPIU_QUERY_OPCODE_MAX,
 };
 #endif /* UAPI_UFS_H_ */