[PATCH v2 3/7] nvme: update nvme_id_ns OPTPERF constants

[Caleb Sander Mateos <csander@purestorage.com>]

In NVMe verson 2.0 and below, OPTPERF comprises only bit 4 of NSFEAT in
the Identify Namespace structure. Since version 2.1, OPTPERF includes
both bits 4 and 5 of NSFEAT. Replace the NVME_NS_FEAT_IO_OPT constant
with NVME_NS_FEAT_OPTPERF_SHIFT, NVME_NS_FEAT_OPTPERF_MASK, and
NVME_NS_FEAT_OPTPERF_MASK_2_1, representing the first bit, pre-2.1 bit
width, and post-2.1 bit width of OPTPERF.

Update nvme_update_disk_info() to check both OPTPERF bits for
controllers that report version 2.1 or newer, as NPWG and NOWS are
supported even if only bit 5 is set.

Signed-off-by: Caleb Sander Mateos <csander@purestorage.com>
---
 drivers/nvme/host/core.c | 8 +++++++-
 include/linux/nvme.h     | 4 +++-
 2 files changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 8dda2fe69789..bff6f26d7bcf 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2062,10 +2062,11 @@ static bool nvme_update_disk_info(struct nvme_ns *ns, struct nvme_id_ns *id,
 	struct nvme_ns_head *head = ns->head;
 	struct nvme_ctrl *ctrl = ns->ctrl;
 	u32 bs = 1U << head->lba_shift;
 	u32 atomic_bs, phys_bs, io_opt = 0;
 	bool valid = true;
+	u8 optperf;
 
 	/*
 	 * The block layer can't support LBA sizes larger than the page size
 	 * or smaller than a sector size yet, so catch this early and don't
 	 * allow block I/O.
@@ -2076,11 +2077,16 @@ static bool nvme_update_disk_info(struct nvme_ns *ns, struct nvme_id_ns *id,
 	}
 
 	phys_bs = bs;
 	atomic_bs = nvme_configure_atomic_write(ns, id, lim, bs);
 
-	if (id->nsfeat & NVME_NS_FEAT_IO_OPT) {
+	optperf = id->nsfeat >> NVME_NS_FEAT_OPTPERF_SHIFT;
+	if (ctrl->vs >= NVME_VS(2, 1, 0))
+		optperf &= NVME_NS_FEAT_OPTPERF_MASK_2_1;
+	else
+		optperf &= NVME_NS_FEAT_OPTPERF_MASK;
+	if (optperf) {
 		/* NPWG = Namespace Preferred Write Granularity */
 		phys_bs = bs * (1 + le16_to_cpu(id->npwg));
 		/* NOWS = Namespace Optimal Write Size */
 		if (id->nows)
 			io_opt = bs * (1 + le16_to_cpu(id->nows));
diff --git a/include/linux/nvme.h b/include/linux/nvme.h
index 1134e6bf2d5c..a025447212f8 100644
--- a/include/linux/nvme.h
+++ b/include/linux/nvme.h
@@ -595,11 +595,13 @@ enum {
 };
 
 enum {
 	NVME_NS_FEAT_THIN	= 1 << 0,
 	NVME_NS_FEAT_ATOMICS	= 1 << 1,
-	NVME_NS_FEAT_IO_OPT	= 1 << 4,
+	NVME_NS_FEAT_OPTPERF_SHIFT = 4,
+	NVME_NS_FEAT_OPTPERF_MASK = 0x1,
+	NVME_NS_FEAT_OPTPERF_MASK_2_1 = 0x3,
 	NVME_NS_ATTR_RO		= 1 << 0,
 	NVME_NS_FLBAS_LBA_MASK	= 0xf,
 	NVME_NS_FLBAS_LBA_UMASK	= 0x60,
 	NVME_NS_FLBAS_LBA_SHIFT	= 1,
 	NVME_NS_FLBAS_META_EXT	= 0x10,
-- 
2.45.2