nvme: implement NS Optimal IO Boundary from 1.3 Spec

The NVMe 1.3 spec introduces Namespace Optimal IO Boundaries (NOIOB),
which standardizes the stripe mechanism we currently have quirks for.
This patch implements the necessary logic to handle this new feature.

Signed-off-by: Scott Bauer <scott.bauer@intel.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>

drivers/nvme/host/core.c

@@ -1080,6 +1080,12 @@ static void nvme_init_integrity(struct nvme_ns *ns)
 }
 #endif /* CONFIG_BLK_DEV_INTEGRITY */
 
+static void nvme_set_chunk_size(struct nvme_ns *ns)
+{
+	u32 chunk_size = (((u32)ns->noiob) << (ns->lba_shift - 9));
+	blk_queue_chunk_sectors(ns->queue, rounddown_pow_of_two(chunk_size));
+}
+
 static void nvme_config_discard(struct nvme_ns *ns)
 {
 	struct nvme_ctrl *ctrl = ns->ctrl;
@@ -1139,12 +1145,15 @@ static void __nvme_revalidate_disk(struct gendisk *disk, struct nvme_id_ns *id)
 	if (ns->lba_shift == 0)
 		ns->lba_shift = 9;
 	bs = 1 << ns->lba_shift;
+	ns->noiob = le16_to_cpu(id->noiob);
 
 	blk_mq_freeze_queue(disk->queue);
 
 	if (ns->ctrl->ops->flags & NVME_F_METADATA_SUPPORTED)
 		nvme_prep_integrity(disk, id, bs);
 	blk_queue_logical_block_size(ns->queue, bs);
+	if (ns->noiob)
+		nvme_set_chunk_size(ns);
 	if (ns->ms && !blk_get_integrity(disk) && !ns->ext)
 		nvme_init_integrity(ns);
 	if (ns->ms && !(ns->ms == 8 && ns->pi_type) && !blk_get_integrity(disk))

drivers/nvme/host/nvme.h

@@ -202,6 +202,7 @@ struct nvme_ns {
 	bool ext;
 	u8 pi_type;
 	unsigned long flags;
+	u16 noiob;
 
 #define NVME_NS_REMOVING 0
 #define NVME_NS_DEAD     1

include/linux/nvme.h

@@ -282,7 +282,7 @@ struct nvme_id_ns {
 	__le16			nabsn;
 	__le16			nabo;
 	__le16			nabspf;
-	__u16			rsvd46;
+	__le16			noiob;
 	__u8			nvmcap[16];
 	__u8			rsvd64[40];
 	__u8			nguid[16];