mmc: block: Add MMC write packing statistics

The write packing statistics are used for the packed commands unit tests
in order to determine test success or failure

Change-Id: I5eea513991c794543fbb3d009d8b7db0b0912fc5
Signed-off-by: Maya Erez <merez@codeaurora.org>
Signed-off-by: Tatyana Brokhman <tlinder@codeaurora.org>
[subhashj@codeaurora.org: fixed trivial merge conflicts]
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>
[xiaonian@codeaurora.org: fix trivial merge conflict]
Signed-off-by: Xiaonian Wang <xiaonian@codeaurora.org>
diff --git a/drivers/mmc/card/block.c b/drivers/mmc/card/block.c
index 3244d04..383992d8 100644
--- a/drivers/mmc/card/block.c
+++ b/drivers/mmc/card/block.c
@@ -69,6 +69,12 @@
 #define PACKED_CMD_VER	0x01
 #define PACKED_CMD_WR	0x02
 
+#define MMC_BLK_UPDATE_STOP_REASON(stats, reason)			\
+	do {								\
+		if (stats->enabled)					\
+			stats->pack_stop_reason[reason]++;		\
+	} while (0)
+
 static DEFINE_MUTEX(block_mutex);
 
 /*
@@ -1992,6 +1998,35 @@
 		mq->wr_packing_enabled = true;
 }
 
+struct mmc_wr_pack_stats *mmc_blk_get_packed_statistics(struct mmc_card *card)
+{
+	if (!card)
+		return NULL;
+
+	return &card->wr_pack_stats;
+}
+EXPORT_SYMBOL(mmc_blk_get_packed_statistics);
+
+void mmc_blk_init_packed_statistics(struct mmc_card *card)
+{
+	int max_num_of_packed_reqs = 0;
+
+	if (!card || !card->wr_pack_stats.packing_events)
+		return;
+
+	max_num_of_packed_reqs = card->ext_csd.max_packed_writes;
+
+	spin_lock(&card->wr_pack_stats.lock);
+	memset(card->wr_pack_stats.packing_events, 0,
+		(max_num_of_packed_reqs + 1) *
+	       sizeof(*card->wr_pack_stats.packing_events));
+	memset(&card->wr_pack_stats.pack_stop_reason, 0,
+		sizeof(card->wr_pack_stats.pack_stop_reason));
+	card->wr_pack_stats.enabled = true;
+	spin_unlock(&card->wr_pack_stats.lock);
+}
+EXPORT_SYMBOL(mmc_blk_init_packed_statistics);
+
 static u8 mmc_blk_prep_packed_list(struct mmc_queue *mq, struct request *req)
 {
 	struct request_queue *q = mq->queue;
@@ -2005,6 +2040,7 @@
 	bool put_back = true;
 	u8 max_packed_rw = 0;
 	u8 reqs = 0;
+	struct mmc_wr_pack_stats *stats = &card->wr_pack_stats;
 
 	/*
 	 * We don't need to check packed for any further
@@ -2055,6 +2091,7 @@
 		phys_segments += mmc_calc_packed_hdr_segs(q, card);
 	}
 
+	spin_lock(&stats->lock);
 	do {
 		if (reqs >= max_packed_rw - 1) {
 			put_back = false;
@@ -2065,33 +2102,48 @@
 		next = blk_fetch_request(q);
 		spin_unlock_irq(q->queue_lock);
 		if (!next) {
+			MMC_BLK_UPDATE_STOP_REASON(stats, EMPTY_QUEUE);
 			put_back = false;
 			break;
 		}
 
 		if (mmc_large_sector(card) &&
-		    !IS_ALIGNED(blk_rq_sectors(next), 8))
+		    !IS_ALIGNED(blk_rq_sectors(next), 8)) {
+			MMC_BLK_UPDATE_STOP_REASON(stats, LARGE_SEC_ALIGN);
 			break;
+		}
 
 		if (req_op(next) == REQ_OP_DISCARD ||
 		    req_op(next) == REQ_OP_SECURE_ERASE ||
-		    req_op(next) == REQ_OP_FLUSH)
+		    req_op(next) == REQ_OP_FLUSH) {
+			if (req_op(next) != REQ_OP_SECURE_ERASE)
+				MMC_BLK_UPDATE_STOP_REASON(stats, FLUSH_OR_DISCARD);
 			break;
+		}
 
-		if (rq_data_dir(cur) != rq_data_dir(next))
+		if (rq_data_dir(cur) != rq_data_dir(next)) {
+			MMC_BLK_UPDATE_STOP_REASON(stats, WRONG_DATA_DIR);
 			break;
+		}
 
 		if (mmc_req_rel_wr(next) &&
-		    (md->flags & MMC_BLK_REL_WR) && !en_rel_wr)
+		    (md->flags & MMC_BLK_REL_WR) && !en_rel_wr) {
+			MMC_BLK_UPDATE_STOP_REASON(stats, REL_WRITE);
 			break;
+		}
 
 		req_sectors += blk_rq_sectors(next);
-		if (req_sectors > max_blk_count)
+		if (req_sectors > max_blk_count) {
+			if (stats->enabled)
+				stats->pack_stop_reason[EXCEEDS_SECTORS]++;
 			break;
+		}
 
 		phys_segments +=  next->nr_phys_segments;
-		if (phys_segments > max_phys_segs)
+		if (phys_segments > max_phys_segs) {
+			MMC_BLK_UPDATE_STOP_REASON(stats, EXCEEDS_SEGMENTS);
 			break;
+		}
 
 		if (rq_data_dir(next) == WRITE)
 			mq->num_of_potential_packed_wr_reqs++;
@@ -2106,6 +2158,15 @@
 		spin_unlock_irq(q->queue_lock);
 	}
 
+	if (stats->enabled) {
+		if (reqs + 1 <= card->ext_csd.max_packed_writes)
+			stats->packing_events[reqs + 1]++;
+		if (reqs + 1 == max_packed_rw)
+			MMC_BLK_UPDATE_STOP_REASON(stats, THRESHOLD);
+	}
+
+	spin_unlock(&stats->lock);
+
 	if (reqs > 0) {
 		list_add(&req->queuelist, &mqrq->packed->list);
 		mqrq->packed->nr_entries = ++reqs;