[PATCH v9 10/13] nvme-pci: Add support for P2P memory in requests
From: Logan Gunthorpe <logang@deltatee.com>
Date: 2018-10-04 21:28:05
Also in:
linux-nvme, linux-pci, linux-rdma, lkml, nvdimm
Subsystem:
nvm express driver, the rest · Maintainers:
Keith Busch, Jens Axboe, Christoph Hellwig, Sagi Grimberg, Linus Torvalds
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: Logan Gunthorpe <logang@deltatee.com> Reviewed-by: Sagi Grimberg <sagi@grimberg.me> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Keith Busch <redacted> --- drivers/nvme/host/core.c | 4 ++++ drivers/nvme/host/nvme.h | 1 + drivers/nvme/host/pci.c | 17 +++++++++++++---- 3 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index dd8ec1dd9219..6033ce2fd3e9 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c@@ -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;
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index bb4a2003c097..4030743c90aa 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h@@ -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);
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index f434706a04e8..0d6c41bc2b35 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c@@ -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) { - dma_unmap_sg(dev->dev, iod->sg, iod->nents, dma_dir); + /* 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,
--
2.19.0