[PATCHv2] nvme: simplify stripe quirk

[Keith Busch]

Some OEMs believe they own the Identify Controller vendor specific
region and will repurpose it with their own values. While not common,
we can't rely on the PCI VID:DID to tell use how to decode the field
we reserved for this as the stripe size so we need to do something else
for the list of devices using this quirk.

The field was supposed to allow flexibility on the device's back-end
striping, but it turned out that never materialized; the chunk is always
the same as MDTS in the products subscribing to this quirk, so this
patch removes the stripe_size field and sets the chunk to the max hw
transfer size for the devices using this quirk.

Signed-off-by: Keith Busch <keith.busch at intel.com>
Acked-by: Christoph Hellwig <hch at lst.de>
---
v1->v2:
  Updated change log to something much less ambiguous.

 drivers/nvme/host/core.c | 17 ++---------------
 drivers/nvme/host/nvme.h |  1 -
 2 files changed, 2 insertions(+), 16 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index b40cfb0..2fc86dc 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -1193,8 +1193,8 @@ static void nvme_set_queue_limits(struct nvme_ctrl *ctrl,
 		blk_queue_max_hw_sectors(q, ctrl->max_hw_sectors);
 		blk_queue_max_segments(q, min_t(u32, max_segments, USHRT_MAX));
 	}
-	if (ctrl->stripe_size)
-		blk_queue_chunk_sectors(q, ctrl->stripe_size >> 9);
+	if (ctrl->quirks & NVME_QUIRK_STRIPE_SIZE)
+		blk_queue_chunk_sectors(q, ctrl->max_hw_sectors);
 	blk_queue_virt_boundary(q, ctrl->page_size - 1);
 	if (ctrl->vwc & NVME_CTRL_VWC_PRESENT)
 		vwc = true;
@@ -1250,19 +1250,6 @@ int nvme_init_identify(struct nvme_ctrl *ctrl)
 	ctrl->max_hw_sectors =
 		min_not_zero(ctrl->max_hw_sectors, max_hw_sectors);
 
-	if ((ctrl->quirks & NVME_QUIRK_STRIPE_SIZE) && id->vs[3]) {
-		unsigned int max_hw_sectors;
-
-		ctrl->stripe_size = 1 << (id->vs[3] + page_shift);
-		max_hw_sectors = ctrl->stripe_size >> (page_shift - 9);
-		if (ctrl->max_hw_sectors) {
-			ctrl->max_hw_sectors = min(max_hw_sectors,
-							ctrl->max_hw_sectors);
-		} else {
-			ctrl->max_hw_sectors = max_hw_sectors;
-		}
-	}
-
 	nvme_set_queue_limits(ctrl, ctrl->admin_q);
 	ctrl->sgls = le32_to_cpu(id->sgls);
 	ctrl->kas = le16_to_cpu(id->kas);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index bd53214..6377e14 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -135,7 +135,6 @@ struct nvme_ctrl {
 
 	u32 page_size;
 	u32 max_hw_sectors;
-	u32 stripe_size;
 	u16 oncs;
 	u16 vid;
 	atomic_t abort_limit;
-- 
2.5.5