scsi: ufs: add queue fullness statistics

Add more statistics to allow tracking of tags occupancy
upon sending a new request. The statistics is kept separately
for 4 types of requests: read, write, urgent and flush.
All will consist only of data requests (eg. read, write, urgent).
This statistic is an enhancement of current tag statistic and
uses same infrastructure.

Change-Id: If5cea4aec4e94081d568a3661584b31665becfc6
Signed-off-by: Dolev Raviv <draviv@codeaurora.org>
[subhashj@codeaurora.org: resolved trivial merge conflicts]
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>

drivers/scsi/ufs/debugfs.c

@@ -169,15 +169,17 @@ static void ufsdbg_setup_fault_injection(struct ufs_hba *hba)
 #endif /* CONFIG_UFS_FAULT_INJECTION */
 
 #define BUFF_LINE_CAPACITY 16
+#define TAB_CHARS 8
 
 static int ufsdbg_tag_stats_show(struct seq_file *file, void *data)
 {
 	struct ufs_hba *hba = (struct ufs_hba *)file->private;
 	struct ufs_stats *ufs_stats;
-	int i;
+	int i, j;
 	int max_depth;
 	bool is_tag_empty = true;
 	unsigned long flags;
+	char *sep = " | * | ";
 
 	if (!hba)
 		goto exit;
@@ -186,27 +188,44 @@ static int ufsdbg_tag_stats_show(struct seq_file *file, void *data)
 
 	if (!ufs_stats->enabled) {
 		pr_debug("%s: ufs statistics are disabled\n", __func__);
+		seq_puts(file, "ufs statistics are disabled");
 		goto exit;
 	}
 
 	max_depth = hba->nutrs;
 
-	pr_debug("%s: UFS tag statistics:\n", __func__);
-	pr_debug("%s: Max tagged command queue depth is %d",
-		__func__, max_depth);
-
 	spin_lock_irqsave(hba->host->host_lock, flags);
-
-	for (i = 0 ; i < max_depth ; ++i) {
-		if (hba->ufs_stats.tag_stats[i] != 0) {
-			is_tag_empty = false;
-			seq_printf(file,
-				 "%s: Dispatched tag %d - %llu times\n",
-				__func__, i, ufs_stats->tag_stats[i]);
-
-			pr_debug("%s: Dispatched tag %d - %llu times\n",
-				__func__, i, ufs_stats->tag_stats[i]);
+	/* Header */
+	seq_printf(file, " Tag Stat\t\t%s Queue Fullness\n", sep);
+	for (i = 0; i < TAB_CHARS * (TS_NUM_STATS + 4); i++) {
+		seq_puts(file, "-");
+		if (i == (TAB_CHARS * 3 - 1))
+			seq_puts(file, sep);
 	}
+	seq_printf(file,
+		"\n #\tnum uses\t%s\t #\tAll\t Read\t Write\t Urgent\t Flush\n",
+		sep);
+
+	/* values */
+	for (i = 0; i < max_depth; i++) {
+		if (ufs_stats->tag_stats[i][0] <= 0 &&
+				ufs_stats->tag_stats[i][1] <= 0 &&
+				ufs_stats->tag_stats[i][2] <= 0 &&
+				ufs_stats->tag_stats[i][3] <= 0 &&
+				ufs_stats->tag_stats[i][4] <= 0)
+			continue;
+
+		is_tag_empty = false;
+		seq_printf(file, " %d\t ", i);
+		for (j = 0; j < TS_NUM_STATS; j++) {
+			seq_printf(file, "%llu\t ", ufs_stats->tag_stats[i][j]);
+			if (j == 0)
+				seq_printf(file, "\t%s\t %d\t%llu\t ", sep, i,
+						ufs_stats->tag_stats[i][j+1] +
+						ufs_stats->tag_stats[i][j+2] +
+						ufs_stats->tag_stats[i][j+3]);
+		}
+		seq_puts(file, "\n");
 	}
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
 
@@ -229,7 +248,7 @@ static ssize_t ufsdbg_tag_stats_write(struct file *filp,
 	struct ufs_hba *hba = filp->f_mapping->host->i_private;
 	struct ufs_stats *ufs_stats;
 	int val = 0;
-	int ret;
+	int ret, bit = 0;
 	unsigned long flags;
 
 	ret = kstrtoint_from_user(ubuf, cnt, 0, &val);
@@ -248,8 +267,15 @@ static ssize_t ufsdbg_tag_stats_write(struct file *filp,
 		ufs_stats->enabled = true;
 		pr_debug("%s: Enabling & Resetting UFS tag statistics",
 			 __func__);
-		memset(ufs_stats->tag_stats, 0,
-		       sizeof(*ufs_stats->tag_stats) * hba->nutrs);
+		memset(hba->ufs_stats.tag_stats[0], 0,
+			sizeof(**hba->ufs_stats.tag_stats) *
+			TS_NUM_STATS * hba->nutrs);
+
+		/* initialize current queue depth */
+		ufs_stats->q_depth = 0;
+		for_each_set_bit_from(bit, &hba->outstanding_reqs, hba->nutrs)
+			ufs_stats->q_depth++;
+		pr_debug("%s: Enabled UFS tag statistics", __func__);
 	}
 
 	spin_unlock_irqrestore(hba->host->host_lock, flags);
@@ -264,19 +290,29 @@ static const struct file_operations ufsdbg_tag_stats_fops = {
 
 static int ufshcd_init_tag_statistics(struct ufs_hba *hba)
 {
+	struct ufs_stats *stats = &hba->ufs_stats;
 	int ret = 0;
+	int i;
 
-	hba->ufs_stats.tag_stats = kzalloc(hba->nutrs * sizeof(u64),
+	stats->enabled = false;
+	stats->tag_stats = kzalloc(sizeof(*stats->tag_stats) * hba->nutrs,
 			GFP_KERNEL);
-	if (!hba->ufs_stats.tag_stats) {
-		dev_err(hba->dev,
-			"%s: Unable to allocate UFS tag_stats", __func__);
-		ret = -ENOMEM;
+	if (!hba->ufs_stats.tag_stats)
+		goto no_mem;
+
+	stats->tag_stats[0] = kzalloc(sizeof(**stats->tag_stats) *
+			TS_NUM_STATS * hba->nutrs, GFP_KERNEL);
+	if (!stats->tag_stats[0])
+		goto no_mem;
+
+	for (i = 1; i < hba->nutrs; i++)
+		stats->tag_stats[i] = &stats->tag_stats[0][i * TS_NUM_STATS];
+
 	goto exit;
-	}
-
-	hba->ufs_stats.enabled = false;
 
+no_mem:
+	dev_err(hba->dev, "%s: Unable to allocate UFS tag_stats", __func__);
+	ret = -ENOMEM;
 exit:
 	return ret;
 }

drivers/scsi/ufs/ufshcd.c

@@ -3,7 +3,7 @@
  *
  * This code is based on drivers/scsi/ufs/ufshcd.c
  * Copyright (C) 2011-2013 Samsung India Software Operations
- * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
+ * Copyright (c) 2013, The Linux Foundation. All rights reserved.
  *
  * Authors:
  *	Santosh Yaraganavi <santosh.sy@samsung.com>
@@ -51,19 +51,47 @@
 #ifdef CONFIG_DEBUG_FS
 #define UFSHCD_UPDATE_TAG_STATS(hba, tag)			\
 	do {							\
-		if (hba->ufs_stats.enabled) {			\
-			hba->ufs_stats.tag_stats[tag]++;	\
-		}						\
-	} while (0);
+		struct request *rq = hba->lrb[task_tag].cmd ?	\
+			hba->lrb[task_tag].cmd->request : NULL;	\
+		u64 **tag_stats = hba->ufs_stats.tag_stats;	\
+		int rq_type = -1;				\
+		if (!hba->ufs_stats.enabled)			\
+			break;					\
+		tag_stats[tag][TS_TAG]++;			\
+		if (!rq)					\
+			break;					\
+		WARN_ON(hba->ufs_stats.q_depth > hba->nutrs);	\
+		if (rq_data_dir(rq) == READ)			\
+			rq_type = (rq->cmd_flags & REQ_URGENT) ?\
+				TS_URGENT : TS_READ;		\
+		else if (rq_data_dir(rq) == WRITE)		\
+			rq_type = TS_WRITE;			\
+		else if (rq->cmd_flags & REQ_FLUSH)		\
+			rq_type = TS_FLUSH;			\
+		else						\
+			break;					\
+		tag_stats[hba->ufs_stats.q_depth++][rq_type]++;	\
+	} while (0)
+
+#define UFSHCD_UPDATE_TAG_STATS_COMPLETION(hba, cmd)		\
+	do {							\
+		struct request *rq = cmd ? cmd->request : NULL;	\
+		if (cmd->request &&				\
+				((rq_data_dir(rq) == READ) ||	\
+				(rq_data_dir(rq) == WRITE) ||	\
+				(rq->cmd_flags & REQ_FLUSH)))	\
+			hba->ufs_stats.q_depth--;		\
+	} while (0)
 
 #define UFSDBG_ADD_DEBUGFS(hba)		ufsdbg_add_debugfs(hba);
 
 #define UFSDBG_REMOVE_DEBUGFS(hba)	ufsdbg_remove_debugfs(hba);
 
 #else
-#define UFSHCD_UPDATE_TAG_STATS(hba, tag)	do {} while (0);
-#define UFSDBG_ADD_DEBUGFS(hba)		do {} while (0);
-#define UFSDBG_REMOVE_DEBUGFS(hba)		do {} while (0);
+#define UFSHCD_UPDATE_TAG_STATS(hba, tag)
+#define UFSHCD_UPDATE_TAG_STATS_COMPLETION(hba, cmd)
+#define UFSDBG_ADD_DEBUGFS(hba)
+#define UFSDBG_REMOVE_DEBUGFS(hba)
 
 #endif
 
@@ -934,7 +962,7 @@ void ufshcd_send_command(struct ufs_hba *hba, unsigned int task_tag)
 	ufshcd_clk_scaling_start_busy(hba);
 	__set_bit(task_tag, &hba->outstanding_reqs);
 	ufshcd_writel(hba, 1 << task_tag, REG_UTP_TRANSFER_REQ_DOOR_BELL);
-	UFSHCD_UPDATE_TAG_STATS(hba, task_tag)
+	UFSHCD_UPDATE_TAG_STATS(hba, task_tag);
 }
 
 /**
@@ -3467,6 +3495,7 @@ static void ufshcd_transfer_req_compl(struct ufs_hba *hba)
 		lrbp = &hba->lrb[index];
 		cmd = lrbp->cmd;
 		if (cmd) {
+			UFSHCD_UPDATE_TAG_STATS_COMPLETION(hba, cmd);
 			result = ufshcd_transfer_rsp_status(hba, lrbp);
 			scsi_dma_unmap(cmd);
 			cmd->result = result;

drivers/scsi/ufs/ufshcd.h

@@ -3,6 +3,7 @@
  *
  * This code is based on drivers/scsi/ufs/ufshcd.h
  * Copyright (C) 2011-2013 Samsung India Software Operations
+ * Copyright (c) 2013-2014, The Linux Foundation. All rights reserved.
  *
  * Authors:
  *	Santosh Yaraganavi <santosh.sy@samsung.com>
@@ -337,8 +338,9 @@ struct ufs_init_prefetch {
 
 #ifdef CONFIG_DEBUG_FS
 struct ufs_stats {
-	u64 *tag_stats;
 	bool enabled;
+	u64 **tag_stats;
+	int q_depth;
 };
 
 struct debugfs_files {
@@ -351,6 +353,17 @@ struct debugfs_files {
 	struct fault_attr fail_attr;
 #endif
 };
+
+/* tag stats statistics types */
+enum ts_types {
+	TS_NOT_SUPPORTED	= -1,
+	TS_TAG			= 0,
+	TS_READ			= 1,
+	TS_WRITE		= 2,
+	TS_URGENT		= 3,
+	TS_FLUSH		= 4,
+	TS_NUM_STATS		= 5,
+};
 #endif
 
 /**