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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,
        iommu@lists.linux.dev
Cc:     Stephen Bates <sbates@raithlin.com>,
        Christoph Hellwig <hch@lst.de>,
        Dan Williams <dan.j.williams@intel.com>,
        Jason Gunthorpe <jgg@ziepe.ca>,
        =?UTF-8?q?Christian=20K=C3=B6nig?= <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>,
        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>,
        Martin Oliveira <martin.oliveira@eideticom.com>,
        Chaitanya Kulkarni <ckulkarnilinux@gmail.com>,
        Ralph Campbell <rcampbell@nvidia.com>,
        Logan Gunthorpe <logang@deltatee.com>,
        Chaitanya Kulkarni <kch@nvidia.com>
Date:   Fri,  8 Jul 2022 10:51:00 -0600
Message-Id: <20220708165104.5005-10-logang@deltatee.com>
In-Reply-To: <20220708165104.5005-1-logang@deltatee.com>
References: <20220708165104.5005-1-logang@deltatee.com>
MIME-Version: 1.0
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Subject: [PATCH v8 09/13] nvme-pci: check DMA ops when indicating support for PCI P2PDMA
Precedence: bulk

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>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
---
 drivers/nvme/host/core.c |  3 ++-
 drivers/nvme/host/nvme.h |  2 +-
 drivers/nvme/host/pci.c  | 12 +++++++++---
 3 files changed, 12 insertions(+), 5 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index ec6ac298d8de..2831e248dd71 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -3996,7 +3996,8 @@ 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->ctrl = ctrl;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 5558f8812157..ea097bb1edde 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -495,7 +495,6 @@ 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);
@@ -505,6 +504,7 @@ struct nvme_ctrl_ops {
 	void (*stop_ctrl)(struct nvme_ctrl *ctrl);
 	int (*get_address)(struct nvme_ctrl *ctrl, char *buf, int size);
 	void (*print_device_info)(struct nvme_ctrl *ctrl);
+	bool (*supports_pci_p2pdma)(struct nvme_ctrl *ctrl);
 };
 
 /*
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index e7af2234e53b..0f556e954ffc 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -2984,7 +2984,6 @@ 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 void nvme_pci_print_device_info(struct nvme_ctrl *ctrl)
 {
 	struct pci_dev *pdev = to_pci_dev(to_nvme_dev(ctrl)->dev);
@@ -2999,11 +2998,17 @@ static void nvme_pci_print_device_info(struct nvme_ctrl *ctrl)
 		subsys->firmware_rev);
 }
 
+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,
@@ -3011,6 +3016,7 @@ static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {
 	.submit_async_event	= nvme_pci_submit_async_event,
 	.get_address		= nvme_pci_get_address,
 	.print_device_info	= nvme_pci_print_device_info,
+	.supports_pci_p2pdma	= nvme_pci_supports_pci_p2pdma,
 };
 
 static int nvme_dev_map(struct nvme_dev *dev)
-- 
2.30.2