[PATCH 02/16] block: add blk_queue_zone_aligned and bdev_zone_aligned helper

[Pankaj Raghav]

Checking if a given sector is aligned to a zone is a very common
operation that is performed for zoned devices. Add
blk_queue_zone_aligned helper to check for this instead of opencoding it
everywhere.

The helper is made to be generic so that it can also check for alignment
for non non-power-of-2 zone size devices.

As the existing deployments of zoned devices had power-of-2
assumption, power-of-2 optimized calculation is done for devices with
power-of-2 zone size

Reviewed-by: Luis Chamberlain <mcgrof at kernel.org>
Signed-off-by: Pankaj Raghav <p.raghav at samsung.com>
---
 include/linux/blkdev.h | 31 +++++++++++++++++++++++++++++++
 1 file changed, 31 insertions(+)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index c4e4c7071b7b..f8f2d2998afb 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -676,6 +676,22 @@ static inline unsigned int blk_queue_zone_no(struct request_queue *q,
 	return div64_u64(sector, zone_sectors);
 }
 
+static inline bool blk_queue_zone_aligned(struct request_queue *q, sector_t sec)
+{
+	sector_t zone_sectors = blk_queue_zone_sectors(q);
+	u64 remainder = 0;
+
+	if (!blk_queue_is_zoned(q))
+		return false;
+
+	if (is_power_of_2(zone_sectors))
+		return IS_ALIGNED(sec, zone_sectors);
+
+	div64_u64_rem(sec, zone_sectors, &remainder);
+	/* if there is a remainder, then the sector is not aligned */
+	return remainder == 0;
+}
+
 static inline bool blk_queue_zone_is_seq(struct request_queue *q,
 					 sector_t sector)
 {
@@ -722,6 +738,12 @@ static inline unsigned int blk_queue_zone_no(struct request_queue *q,
 {
 	return 0;
 }
+
+static inline bool blk_queue_zone_aligned(struct request_queue *q, sector_t sec)
+{
+	return false;
+}
+
 static inline unsigned int queue_max_open_zones(const struct request_queue *q)
 {
 	return 0;
@@ -1361,6 +1383,15 @@ static inline sector_t bdev_zone_sectors(struct block_device *bdev)
 	return 0;
 }
 
+static inline bool bdev_zone_aligned(struct block_device *bdev, sector_t sec)
+{
+	struct request_queue *q = bdev_get_queue(bdev);
+
+	if (q)
+		return blk_queue_zone_aligned(q, sec);
+	return false;
+}
+
 static inline unsigned int bdev_max_open_zones(struct block_device *bdev)
 {
 	struct request_queue *q = bdev_get_queue(bdev);
-- 
2.25.1