Commit e0596ab2 authored by Logan Gunthorpe's avatar Logan Gunthorpe Committed by Bjorn Helgaas
Browse files

nvme-pci: Add support for P2P memory in requests 



For P2P requests, we must use the pci_p2pmem_map_sg() function instead of
the dma_map_sg functions.

With that, we can then indicate PCI_P2P support in the request queue.  For
this, we create an NVME_F_PCI_P2P flag which tells the core to set
QUEUE_FLAG_PCI_P2P in the request queue.

Signed-off-by: default avatarLogan Gunthorpe <logang@deltatee.com>
Signed-off-by: default avatarBjorn Helgaas <bhelgaas@google.com>
Reviewed-by: default avatarSagi Grimberg <sagi@grimberg.me>
Reviewed-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarKeith Busch <keith.busch@intel.com>
parent 0f238ff5

drivers/nvme/host/core.c

+4 −0
Original line number Diff line number Diff line
@@ -3051,7 +3051,11 @@ static void nvme_alloc_ns(struct nvme_ctrl *ctrl, unsigned nsid) 
	ns->queue = blk_mq_init_queue(ctrl->tagset);

	if (IS_ERR(ns->queue))

		goto out_free_ns;



	blk_queue_flag_set(QUEUE_FLAG_NONROT, ns->queue);

	if (ctrl->ops->flags & NVME_F_PCI_P2PDMA)

		blk_queue_flag_set(QUEUE_FLAG_PCI_P2PDMA, ns->queue);



	ns->queue->queuedata = ns;

	ns->ctrl = ctrl;

drivers/nvme/host/nvme.h

+1 −0
Original line number Diff line number Diff line
@@ -343,6 +343,7 @@ 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);

drivers/nvme/host/pci.c

+13 −4
Original line number Diff line number Diff line
@@ -745,8 +745,13 @@ static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, 
		goto out;



	ret = BLK_STS_RESOURCE;

	nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents, dma_dir,

			DMA_ATTR_NO_WARN);



	if (is_pci_p2pdma_page(sg_page(iod->sg)))

		nr_mapped = pci_p2pdma_map_sg(dev->dev, iod->sg, iod->nents,

					  dma_dir);

	else

		nr_mapped = dma_map_sg_attrs(dev->dev, iod->sg, iod->nents,

					     dma_dir,  DMA_ATTR_NO_WARN);

	if (!nr_mapped)

		goto out;
@@ -788,7 +793,10 @@ static void nvme_unmap_data(struct nvme_dev *dev, struct request *req) 
			DMA_TO_DEVICE : DMA_FROM_DEVICE;



	if (iod->nents) {

		/* P2PDMA requests do not need to be unmapped */

		if (!is_pci_p2pdma_page(sg_page(iod->sg)))

			dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir);



		if (blk_integrity_rq(req))

			dma_unmap_sg(dev->dev, &iod->meta_sg, 1, dma_dir);

	}
@@ -2400,7 +2408,8 @@ static int nvme_pci_get_address(struct nvme_ctrl *ctrl, char *buf, int size) 
static const struct nvme_ctrl_ops nvme_pci_ctrl_ops = {

	.name			= "pcie",

	.module			= THIS_MODULE,

	.flags			= NVME_F_METADATA_SUPPORTED,

	.flags			= NVME_F_METADATA_SUPPORTED |

				  NVME_F_PCI_P2PDMA,

	.reg_read32		= nvme_pci_reg_read32,

	.reg_write32		= nvme_pci_reg_write32,

	.reg_read64		= nvme_pci_reg_read64,

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