Skip to contentSkip to conversation

nvme: Implement NS Optimal IO Boundary from 1.3 Spec

PATCH Superseded Scott Bauer 3 participants 5 messages Jun 15, 2017 NVMe

v2 of 3 Superseded Latest is v3 →

lore
Share & tools
lore

Scott Bauer

author
#0 lore raw

PATCH v2 1/1 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 at intel.com>
---
 drivers/nvme/host/core.c | 9 +++++++++
 drivers/nvme/host/nvme.h | 1 +
 include/linux/nvme.h     | 2 +-
 3 files changed, 11 insertions(+), 1 deletion(-)
drivers/nvme/host/core.c +9 -0
index 4ff5114f467d..dfa72bb2ef0c 100644
@@ -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)
+{
+	unsigned int 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 +1 -0
index f27c58b860f4..ec8c7363934d 100644
@@ -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 +1 -1
index 6d476f242ee6..291587a0743f 100644
@@ -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];
Signature · 1 line
2.11.0
author
#1 lore raw

PATCH v2 1/1 nvme: Implement NS Optimal IO Boundary from 1.3 Spec

Quoted 29 lines · Scott Bauer

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 at intel.com>
---
 drivers/nvme/host/core.c | 9 +++++++++
 drivers/nvme/host/nvme.h | 1 +
 include/linux/nvme.h     | 2 +-
 3 files changed, 11 insertions(+), 1 deletion(-)
drivers/nvme/host/core.c +6 -0
index 4ff5114f467d..dfa72bb2ef0c 100644
@@ -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)
+{
+	unsigned int 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;

drivers/nvme/host/core.c static void __nvme_revalidate_disk(struct gendisk *disk, struct nvme_id_ns *id) · line 1148

Quoted 4 lines
drivers/nvme/host/core.c +1 -0
@@ -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);

I need to re-spin this one more time. I forgot to add the 1.3 version check before accessing the register here.

maintainer
#2 lore raw

PATCH v2 1/1 nvme: Implement NS Optimal IO Boundary from 1.3 Spec

Quoted 2 lines · Scott Bauer

I need to re-spin this one more time. I forgot to add the 1.3 version check before accessing the register here.

NVMe TPs also apply to older versions, so we should be fine without the check.

#3 lore raw

PATCH v2 1/1 nvme: Implement NS Optimal IO Boundary from 1.3 Spec

In reply to Scott Bauer
Quoted 16 lines · Scott Bauer

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 at intel.com>
---
 drivers/nvme/host/core.c | 9 +++++++++
 drivers/nvme/host/nvme.h | 1 +
 include/linux/nvme.h     | 2 +-
 3 files changed, 11 insertions(+), 1 deletion(-)
drivers/nvme/host/core.c +0 -0
index 4ff5114f467d..dfa72bb2ef0c 100644

drivers/nvme/host/core.c static void nvme_init_integrity(struct nvme_ns *ns) · line 1085

Quoted 6 lines
drivers/nvme/host/core.c +3 -0
@@ -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)
+{
+	unsigned int chunk_size = (((u32)ns->noiob) << ns->lba_shift) >> 9;

Let's say we've a large noiob (16k) with a 4k block size. The above would shift beyond 32-bits, so I would rewrite this as:

	unsigned int chunk_size = (((u32)ns->noiob) << (ns->lba_shift - 9));
#4 lore raw

PATCH v2 1/1 nvme: Implement NS Optimal IO Boundary from 1.3 Spec

Quoted 4 lines · Keith Busch

Let's say we've a large noiob (16k) with a 4k block size. The above would shift beyond 32-bits, so I would rewrite this as:

	unsigned int chunk_size = (((u32)ns->noiob) << (ns->lba_shift - 9));

Oops, please disregard the fact I'm can't count overflow correctly...

I still prefer the alternate shift calculation, though.