[PATCH v2 18/22] nvme-pci: Check DMA ops when indicating support for PCI P2PDMA

From: Logan Gunthorpe <logang@deltatee.com>
To: linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org,
	linux-block@vger.kernel.org, linux-pci@vger.kernel.org,
	linux-mm@kvack.org, iommu@lists.linux-foundation.org
Cc: "Stephen Bates" <sbates@raithlin.com>,
	"Christoph Hellwig" <hch@lst.de>,
	"Dan Williams" <dan.j.williams@intel.com>,
	"Jason Gunthorpe" <jgg@ziepe.ca>,
	"Christian König" <christian.koenig@amd.com>,
	"John Hubbard" <jhubbard@nvidia.com>,
	"Don Dutile" <ddutile@redhat.com>,
	"Matthew Wilcox" <willy@infradead.org>,
	"Daniel Vetter" <daniel.vetter@ffwll.ch>,
	"Jakowski Andrzej" <andrzej.jakowski@intel.com>,
	"Minturn Dave B" <dave.b.minturn@intel.com>,
	"Jason Ekstrand" <jason@jlekstrand.net>,
	"Dave Hansen" <dave.hansen@linux.intel.com>,
	"Xiong Jianxin" <jianxin.xiong@intel.com>,
	"Bjorn Helgaas" <helgaas@kernel.org>,
	"Ira Weiny" <ira.weiny@intel.com>,
	"Robin Murphy" <robin.murphy@arm.com>,
	"Logan Gunthorpe" <logang@deltatee.com>
Subject: [PATCH v2 18/22] nvme-pci: Check DMA ops when indicating support for PCI P2PDMA
Date: Thu, 13 May 2021 16:31:59 -0600	[thread overview]
Message-ID: <20210513223203.5542-19-logang@deltatee.com> (raw)
In-Reply-To: <20210513223203.5542-1-logang@deltatee.com>

Introduce a supports_pci_p2pdma() operation in nvme_ctrl_ops to
replace the fixed NVME_F_PCI_P2PDMA flag such that the dma_map_ops
flags can be checked for PCI P2PDMA support.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
 drivers/nvme/host/core.c |  3 ++-
 drivers/nvme/host/nvme.h |  2 +-
 drivers/nvme/host/pci.c  | 11 +++++++++--
 3 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 522c9b229f80..9544a8948bc4 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3682,7 +3682,8 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid,
 		blk_queue_flag_set(QUEUE_FLAG_STABLE_WRITES, ns->queue);
 
 	blk_queue_flag_set(QUEUE_FLAG_NONROT, ns->queue);
-	if (ctrl->ops->flags & NVME_F_PCI_P2PDMA)
+	if (ctrl->ops->supports_pci_p2pdma &&
+	    ctrl->ops->supports_pci_p2pdma(ctrl))
 		blk_queue_flag_set(QUEUE_FLAG_PCI_P2PDMA, ns->queue);
 
 	ns->queue->queuedata = ns;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 05f31a2c64bb..84649ce6c206 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -487,7 +487,6 @@ struct nvme_ctrl_ops {
 	unsigned int flags;
 #define NVME_F_FABRICS			(1 << 0)
 #define NVME_F_METADATA_SUPPORTED	(1 << 1)
-#define NVME_F_PCI_P2PDMA		(1 << 2)
 	int (*reg_read32)(struct nvme_ctrl *ctrl, u32 off, u32 *val);
 	int (*reg_write32)(struct nvme_ctrl *ctrl, u32 off, u32 val);
 	int (*reg_read64)(struct nvme_ctrl *ctrl, u32 off, u64 *val);
@@ -495,6 +494,7 @@ struct nvme_ctrl_ops {
 	void (*submit_async_event)(struct nvme_ctrl *ctrl);
 	void (*delete_ctrl)(struct nvme_ctrl *ctrl);
 	int (*get_address)(struct nvme_ctrl *ctrl, char *buf, int size);
+	bool (*supports_pci_p2pdma)(struct nvme_ctrl *ctrl);
 };
 
 #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index a29b170701fc..9912291f43af 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2756,17 +2756,24 @@ static int nvme_pci_get_address(struct nvme_ctrl *ctrl, char *buf, int size)
 	return snprintf(buf, size, "%s\n", dev_name(&pdev->dev));
 }
 
+static bool nvme_pci_supports_pci_p2pdma(struct nvme_ctrl *ctrl)
+{
+	struct nvme_dev *dev = to_nvme_dev(ctrl);
+
+	return dma_pci_p2pdma_supported(dev->dev);
+}
+
 static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
 	.name			= "pcie",
 	.module			= THIS_MODULE,
-	.flags			= NVME_F_METADATA_SUPPORTED |
-				  NVME_F_PCI_P2PDMA,
+	.flags			= NVME_F_METADATA_SUPPORTED,
 	.reg_read32		= nvme_pci_reg_read32,
 	.reg_write32		= nvme_pci_reg_write32,
 	.reg_read64		= nvme_pci_reg_read64,
 	.free_ctrl		= nvme_pci_free_ctrl,
 	.submit_async_event	= nvme_pci_submit_async_event,
 	.get_address		= nvme_pci_get_address,
+	.supports_pci_p2pdma	= nvme_pci_supports_pci_p2pdma,
 };
 
 static int nvme_dev_map(struct nvme_dev *dev)
-- 
2.20.1

