mmc: core: Add MMC BKOPS statistics and debugfs ability to print them

The BKOPS statistics are used for BKOPS unit tests and APT tests
to determine test success or failure.
the BKOPS statstics provide the following information:
The number of times BKOPS were issued according to it's severity level
The number of times BKOPS were interrupted by HPI.
The number of times the host went into suspend

Change-Id: Ib84319aedfb49dc022bc27efbda842a5db38c7e9
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>

drivers/mmc/core/bus.c

@@ -250,6 +250,7 @@ struct mmc_card *mmc_alloc_card(struct mmc_host *host, struct device_type *type)
 	card->dev.release = mmc_release_card;
 	card->dev.type = type;
 
+	spin_lock_init(&card->bkops_info.bkops_stats.lock);
 	spin_lock_init(&card->wr_pack_stats.lock);
 
 	return card;

drivers/mmc/core/core.c

@@ -83,6 +83,30 @@ MODULE_PARM_DESC(
 	removable,
 	"MMC/SD cards are removable and may be removed during suspend");
 
+#define MMC_UPDATE_BKOPS_STATS_HPI(stats)	\
+	do {					\
+		spin_lock(&stats.lock);		\
+		if (stats.enabled)		\
+			stats.hpi++;		\
+		spin_unlock(&stats.lock);	\
+	} while (0);
+#define MMC_UPDATE_BKOPS_STATS_SUSPEND(stats)	\
+	do {					\
+		spin_lock(&stats.lock);		\
+		if (stats.enabled)		\
+			stats.suspend++;	\
+		spin_unlock(&stats.lock);	\
+	} while (0);
+#define MMC_UPDATE_STATS_BKOPS_SEVERITY_LEVEL(stats, level)		\
+	do {								\
+		if (level <= 0 || level > BKOPS_NUM_OF_SEVERITY_LEVELS)	\
+			break;						\
+		spin_lock(&stats.lock);					\
+		if (stats.enabled)					\
+			stats.bkops_level[level-1]++;			\
+		spin_unlock(&stats.lock);				\
+	} while (0);
+
 /*
  * Internal function. Schedule delayed work in the MMC work queue.
  */
@@ -286,6 +310,29 @@ mmc_start_request(struct mmc_host *host, struct mmc_request *mrq)
 	host->ops->request(host, mrq);
 }
 
+void mmc_blk_init_bkops_statistics(struct mmc_card *card)
+{
+	int i;
+	struct mmc_bkops_stats *bkops_stats;
+
+	if (!card)
+		return;
+
+	bkops_stats = &card->bkops_info.bkops_stats;
+
+	spin_lock(&bkops_stats->lock);
+
+	for (i = 0 ; i < BKOPS_NUM_OF_SEVERITY_LEVELS ; ++i)
+		bkops_stats->bkops_level[i] = 0;
+
+	bkops_stats->suspend = 0;
+	bkops_stats->hpi = 0;
+	bkops_stats->enabled = true;
+
+	spin_unlock(&bkops_stats->lock);
+}
+EXPORT_SYMBOL(mmc_blk_init_bkops_statistics);
+
 /**
  * mmc_start_delayed_bkops() - Start a delayed work to check for
  *      the need of non urgent BKOPS
@@ -392,6 +439,8 @@ void mmc_start_bkops(struct mmc_card *card, bool from_exception)
 			mmc_hostname(card->host), err);
 		goto out;
 	}
+	MMC_UPDATE_STATS_BKOPS_SEVERITY_LEVEL(card->bkops_info.bkops_stats,
+					card->ext_csd.raw_bkops_status);
 
 	/*
 	 * For urgent bkops status (LEVEL_2 and more)
@@ -895,6 +944,8 @@ int mmc_stop_bkops(struct mmc_card *card)
 		err = 0;
 	}
 
+	MMC_UPDATE_BKOPS_STATS_HPI(card->bkops_info.bkops_stats);
+
 out:
 	mmc_release_host(card->host);
 	return err;
@@ -2932,6 +2983,8 @@ int mmc_suspend_host(struct mmc_host *host)
 						goto out;
 				}
 				err = host->bus_ops->suspend(host);
+				MMC_UPDATE_BKOPS_STATS_SUSPEND(host->
+						card->bkops_info.bkops_stats);
 			}
 			if (!(host->card && mmc_card_sdio(host->card)))
 				mmc_release_host(host);

drivers/mmc/core/debugfs.c

@@ -552,6 +552,113 @@ static const struct file_operations mmc_dbg_wr_pack_stats_fops = {
 	.write		= mmc_wr_pack_stats_write,
 };
 
+static int mmc_bkops_stats_open(struct inode *inode, struct file *filp)
+{
+	struct mmc_card *card = inode->i_private;
+
+	filp->private_data = card;
+
+	card->bkops_info.bkops_stats.print_stats = 1;
+	return 0;
+}
+
+static ssize_t mmc_bkops_stats_read(struct file *filp, char __user *ubuf,
+				     size_t cnt, loff_t *ppos)
+{
+	struct mmc_card *card = filp->private_data;
+	struct mmc_bkops_stats *bkops_stats;
+	int i;
+	char *temp_buf;
+
+	if (!card)
+		return cnt;
+
+	bkops_stats = &card->bkops_info.bkops_stats;
+
+	if (!bkops_stats->print_stats)
+		return 0;
+
+	if (!bkops_stats->enabled) {
+		pr_info("%s: bkops statistics are disabled\n",
+			 mmc_hostname(card->host));
+		goto exit;
+	}
+
+	temp_buf = kmalloc(TEMP_BUF_SIZE, GFP_KERNEL);
+	if (!temp_buf)
+		goto exit;
+
+	spin_lock(&bkops_stats->lock);
+
+	memset(ubuf, 0, cnt);
+
+	snprintf(temp_buf, TEMP_BUF_SIZE, "%s: bkops statistics:\n",
+		mmc_hostname(card->host));
+	strlcat(ubuf, temp_buf, cnt);
+
+	for (i = 0 ; i < BKOPS_NUM_OF_SEVERITY_LEVELS ; ++i) {
+		snprintf(temp_buf, TEMP_BUF_SIZE,
+			 "%s: BKOPS: due to level %d: %u\n",
+		 mmc_hostname(card->host), i, bkops_stats->bkops_level[i]);
+		strlcat(ubuf, temp_buf, cnt);
+	}
+
+	snprintf(temp_buf, TEMP_BUF_SIZE,
+		 "%s: BKOPS: stopped due to HPI: %u\n",
+		 mmc_hostname(card->host), bkops_stats->hpi);
+	strlcat(ubuf, temp_buf, cnt);
+
+	snprintf(temp_buf, TEMP_BUF_SIZE,
+		 "%s: BKOPS: how many time host was suspended: %u\n",
+		 mmc_hostname(card->host), bkops_stats->suspend);
+	strlcat(ubuf, temp_buf, cnt);
+
+	spin_unlock(&bkops_stats->lock);
+
+	kfree(temp_buf);
+
+	pr_info("%s", ubuf);
+
+exit:
+	if (bkops_stats->print_stats == 1) {
+		bkops_stats->print_stats = 0;
+		return strnlen(ubuf, cnt);
+	}
+
+	return 0;
+}
+
+static ssize_t mmc_bkops_stats_write(struct file *filp,
+				      const char __user *ubuf, size_t cnt,
+				      loff_t *ppos)
+{
+	struct mmc_card *card = filp->private_data;
+	int value;
+	struct mmc_bkops_stats *bkops_stats;
+
+	if (!card)
+		return cnt;
+
+	bkops_stats = &card->bkops_info.bkops_stats;
+
+	sscanf(ubuf, "%d", &value);
+	if (value) {
+		mmc_blk_init_bkops_statistics(card);
+	} else {
+		spin_lock(&bkops_stats->lock);
+		bkops_stats->enabled = false;
+		spin_unlock(&bkops_stats->lock);
+	}
+
+	return cnt;
+}
+
+static const struct file_operations mmc_dbg_bkops_stats_fops = {
+	.open		= mmc_bkops_stats_open,
+	.read		= mmc_bkops_stats_read,
+	.write		= mmc_bkops_stats_write,
+};
+
 void mmc_add_card_debugfs(struct mmc_card *card)
 {
 	struct mmc_host	*host = card->host;
@@ -590,6 +697,12 @@ void mmc_add_card_debugfs(struct mmc_card *card)
 					 &mmc_dbg_wr_pack_stats_fops))
 			goto err;
 
+	if (mmc_card_mmc(card) && (card->ext_csd.rev >= 6) &&
+	    card->ext_csd.bkops_en)
+		if (!debugfs_create_file("bkops_stats", S_IRUSR, root, card,
+					 &mmc_dbg_bkops_stats_fops))
+			goto err;
+
 	return;
 
 err:

include/linux/mmc/card.h

@@ -246,6 +246,16 @@ struct mmc_part {
 #define MMC_BLK_DATA_AREA_RPMB	(1<<3)
 };
 
+#define BKOPS_NUM_OF_SEVERITY_LEVELS	3
+struct mmc_bkops_stats {
+	spinlock_t		lock;
+	bool			enabled;
+	unsigned int		hpi;    /* hpi issued   */
+	unsigned int		suspend;/* card sleed issued */
+	bool			print_stats;
+	unsigned int bkops_level[BKOPS_NUM_OF_SEVERITY_LEVELS];
+};
+
 /**
  * struct mmc_bkops_info - BKOPS data
  * @dw:	Idle time bkops delayed work
@@ -266,6 +276,7 @@ struct mmc_bkops_info {
 	unsigned int		host_suspend_tout_ms;
 	unsigned int		delay_ms;
 	unsigned int		min_sectors_to_queue_delayed_work;
+	struct mmc_bkops_stats  bkops_stats;    /* BKOPS statistics */
 /*
  * A default time for checking the need for non urgent BKOPS once mmcqd
  * is idle.

include/linux/mmc/core.h

@@ -196,6 +196,8 @@ extern int mmc_flush_cache(struct mmc_card *);
 
 extern int mmc_detect_card_removed(struct mmc_host *host);
 
+extern void mmc_blk_init_bkops_statistics(struct mmc_card *card);
+
 /**
  *	mmc_claim_host - exclusively claim a host
  *	@host: mmc host to claim