[PATCH 2/2] nvme: remove virtual boundary for sgl capable devices

[Keith Busch]

From: Keith Busch <kbusch at kernel.org>

The nvme virtual boundary is only for the PRP format. Devices that can
use the SGL format don't need it for IO queues. Drop reporting it for
such PCIe devices; fabrics target will continue to use the limit.

Applications can still continue to align to it, and the driver can still
decide to use the PRP format if the IO allows it.

Signed-off-by: Keith Busch <kbusch at kernel.org>
---
 drivers/nvme/host/core.c | 14 +++++++++-----
 drivers/nvme/host/pci.c  |  2 ++
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 812c1565114fd..c012c209c7670 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -2065,13 +2065,17 @@ static u32 nvme_max_drv_segments(struct nvme_ctrl *ctrl)
 }
 
 static void nvme_set_ctrl_limits(struct nvme_ctrl *ctrl,
-		struct queue_limits *lim)
+		struct queue_limits *lim, bool admin)
 {
 	lim->max_hw_sectors = ctrl->max_hw_sectors;
 	lim->max_segments = min_t(u32, USHRT_MAX,
 		min_not_zero(nvme_max_drv_segments(ctrl), ctrl->max_segments));
 	lim->max_integrity_segments = ctrl->max_integrity_segments;
-	lim->virt_boundary_mask = NVME_CTRL_PAGE_SIZE - 1;
+	if (!nvme_ctrl_sgl_supported(ctrl) || admin ||
+	    ctrl->ops->flags & NVME_F_FABRICS)
+		lim->virt_boundary_mask = NVME_CTRL_PAGE_SIZE - 1;
+	else
+		lim->virt_boundary_mask = 0;
 	lim->max_segment_size = UINT_MAX;
 	lim->dma_alignment = 3;
 }
@@ -2173,7 +2177,7 @@ static int nvme_update_ns_info_generic(struct nvme_ns *ns,
 	int ret;
 
 	lim = queue_limits_start_update(ns->disk->queue);
-	nvme_set_ctrl_limits(ns->ctrl, &lim);
+	nvme_set_ctrl_limits(ns->ctrl, &lim, false);
 
 	memflags = blk_mq_freeze_queue(ns->disk->queue);
 	ret = queue_limits_commit_update(ns->disk->queue, &lim);
@@ -2377,7 +2381,7 @@ static int nvme_update_ns_info_block(struct nvme_ns *ns,
 	ns->head->lba_shift = id->lbaf[lbaf].ds;
 	ns->head->nuse = le64_to_cpu(id->nuse);
 	capacity = nvme_lba_to_sect(ns->head, le64_to_cpu(id->nsze));
-	nvme_set_ctrl_limits(ns->ctrl, &lim);
+	nvme_set_ctrl_limits(ns->ctrl, &lim, false);
 	nvme_configure_metadata(ns->ctrl, ns->head, id, nvm, info);
 	nvme_set_chunk_sectors(ns, id, &lim);
 	if (!nvme_update_disk_info(ns, id, &lim))
@@ -3580,7 +3584,7 @@ static int nvme_init_identify(struct nvme_ctrl *ctrl)
 		min_not_zero(ctrl->max_hw_sectors, max_hw_sectors);
 
 	lim = queue_limits_start_update(ctrl->admin_q);
-	nvme_set_ctrl_limits(ctrl, &lim);
+	nvme_set_ctrl_limits(ctrl, &lim, true);
 	ret = queue_limits_commit_update(ctrl->admin_q, &lim);
 	if (ret)
 		goto out_free;
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index 4a23729f399ac..ec9eb158b43d7 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -623,6 +623,8 @@ static inline enum nvme_use_sgl nvme_pci_use_sgls(struct nvme_dev *dev,
 			return SGL_FORCED;
 		if (req->nr_integrity_segments > 1)
 			return SGL_FORCED;
+		if (blk_rq_page_gaps(req) & (NVME_CTRL_PAGE_SIZE - 1))
+			return SGL_FORCED;
 		return SGL_SUPPORTED;
 	}
 
-- 
2.47.3