From: Christoph Hellwig <hch@xxxxxx> Use the blk_rq_dma_map API to DMA map requests instead of scatterlists. This also removes the fast path single segment code as the blk_rq_dma_map naturally inlines single IOVA segment mappings into the preallocated structure. Signed-off-by: Christoph Hellwig <hch@xxxxxx> Signed-off-by: Leon Romanovsky <leonro@xxxxxxxxxx> --- drivers/nvme/host/pci.c | 382 +++++++++++++++++++++------------------- 1 file changed, 205 insertions(+), 177 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 79cd65a5f311..f41db1efecb1 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -7,7 +7,7 @@ #include <linux/acpi.h> #include <linux/async.h> #include <linux/blkdev.h> -#include <linux/blk-mq.h> +#include <linux/blk-mq-dma.h> #include <linux/blk-mq-pci.h> #include <linux/blk-integrity.h> #include <linux/dmi.h> @@ -27,7 +27,6 @@ #include <linux/io-64-nonatomic-lo-hi.h> #include <linux/io-64-nonatomic-hi-lo.h> #include <linux/sed-opal.h> -#include <linux/pci-p2pdma.h> #include "trace.h" #include "nvme.h" @@ -227,10 +226,9 @@ struct nvme_iod { bool aborted; u8 nr_descriptors; /* # of PRP/SGL descriptors */ bool large_descriptors; /* uses the full page sized descriptor pool */ - unsigned int dma_len; /* length of single DMA segment mapping */ - dma_addr_t first_dma; + unsigned int total_len; /* length of the entire transfer */ dma_addr_t meta_dma; - struct sg_table sgt; + struct dma_iova_state dma_state; void *descriptors[NVME_MAX_NR_DESCRIPTORS]; }; @@ -527,9 +525,14 @@ static void nvme_free_descriptors(struct nvme_dev *dev, struct request *req) { const int last_prp = NVME_CTRL_PAGE_SIZE / sizeof(__le64) - 1; struct nvme_iod *iod = blk_mq_rq_to_pdu(req); - dma_addr_t dma_addr = iod->first_dma; + dma_addr_t dma_addr; int i; + if (iod->cmd.common.flags & NVME_CMD_SGL_METABUF) + dma_addr = le64_to_cpu(iod->cmd.common.dptr.sgl.addr); + else + dma_addr = le64_to_cpu(iod->cmd.common.dptr.prp2); + if (iod->nr_descriptors == 1) { dma_pool_free(nvme_dma_pool(dev, iod), iod->descriptors[0], dma_addr); @@ -545,67 +548,143 @@ static void nvme_free_descriptors(struct nvme_dev *dev, struct request *req) } } -static void nvme_unmap_data(struct nvme_dev *dev, struct request *req) +static void nvme_free_prps(struct nvme_dev *dev, struct request *req) { struct nvme_iod *iod = blk_mq_rq_to_pdu(req); - - if (iod->dma_len) { - dma_unmap_page(dev->dev, iod->first_dma, iod->dma_len, - rq_dma_dir(req)); + enum dma_data_direction dir = rq_dma_dir(req); + int length = iod->total_len; + dma_addr_t dma_addr; + int prp_len, nprps, i, desc; + __le64 *prp_list; + dma_addr_t dma_start; + u32 dma_len; + + dma_addr = le64_to_cpu(iod->cmd.common.dptr.prp1); + prp_len = NVME_CTRL_PAGE_SIZE - (dma_addr & (NVME_CTRL_PAGE_SIZE - 1)); + prp_len = min(length, prp_len); + length -= prp_len; + if (!length) { + dma_unmap_page(dev->dev, dma_addr, prp_len, dir); return; } - WARN_ON_ONCE(!iod->sgt.nents); + dma_start = dma_addr; + dma_len = prp_len; - dma_unmap_sgtable(dev->dev, &iod->sgt, rq_dma_dir(req), 0); - nvme_free_descriptors(dev, req); - mempool_free(iod->sgt.sgl, dev->iod_mempool); + dma_addr = le64_to_cpu(iod->cmd.common.dptr.prp2); + if (length <= NVME_CTRL_PAGE_SIZE) { + if (dma_addr != dma_start + dma_len) { + dma_unmap_page(dev->dev, dma_start, dma_len, dir); + dma_start = dma_addr; + dma_len = 0; + } + dma_len += length; + goto done; + } + + nprps = DIV_ROUND_UP(length, NVME_CTRL_PAGE_SIZE); + i = 0; + desc = 0; + prp_list = iod->descriptors[desc]; + do { + if (i == NVME_CTRL_PAGE_SIZE >> 3) { + prp_list = iod->descriptors[++desc]; + i = 0; + } + + dma_addr = le64_to_cpu(prp_list[i++]); + if (dma_addr != dma_start + dma_len) { + dma_unmap_page(dev->dev, dma_start, dma_len, dir); + dma_start = dma_addr; + dma_len = 0; + } + prp_len = min(length, NVME_CTRL_PAGE_SIZE); + dma_len += prp_len; + length -= prp_len; + } while (length); +done: + dma_unmap_page(dev->dev, dma_start, dma_len, dir); } -static void nvme_print_sgl(struct scatterlist *sgl, int nents) +static void nvme_free_sgls(struct nvme_dev *dev, struct request *req) { - int i; - struct scatterlist *sg; + struct nvme_iod *iod = blk_mq_rq_to_pdu(req); + dma_addr_t sqe_dma_addr = le64_to_cpu(iod->cmd.common.dptr.sgl.addr); + unsigned int sqe_dma_len = le32_to_cpu(iod->cmd.common.dptr.sgl.length); + struct nvme_sgl_desc *sg_list = iod->descriptors[0]; + enum dma_data_direction dir = rq_dma_dir(req); + + if (iod->nr_descriptors) { + unsigned int nr_entries = sqe_dma_len / sizeof(*sg_list), i; + + for (i = 0; i < nr_entries; i++) + dma_unmap_page(dev->dev, le64_to_cpu(sg_list[i].addr), + le32_to_cpu(sg_list[i].length), dir); + } else { + dma_unmap_page(dev->dev, sqe_dma_addr, sqe_dma_len, dir); + } +} + +static void nvme_unmap_data(struct nvme_dev *dev, struct request *req) +{ + struct nvme_iod *iod = blk_mq_rq_to_pdu(req); - for_each_sg(sgl, sg, nents, i) { - dma_addr_t phys = sg_phys(sg); - pr_warn("sg[%d] phys_addr:%pad offset:%d length:%d " - "dma_address:%pad dma_length:%d\n", - i, &phys, sg->offset, sg->length, &sg_dma_address(sg), - sg_dma_len(sg)); + if (!blk_rq_dma_unmap(req, dev->dev, &iod->dma_state)) { + if (iod->cmd.common.flags & NVME_CMD_SGL_METABUF) + nvme_free_sgls(dev, req); + else + nvme_free_prps(dev, req); } + + if (iod->nr_descriptors) + nvme_free_descriptors(dev, req); } static blk_status_t nvme_pci_setup_prps(struct nvme_dev *dev, struct request *req, struct nvme_rw_command *cmnd) { struct nvme_iod *iod = blk_mq_rq_to_pdu(req); - int length = blk_rq_payload_bytes(req); - struct scatterlist *sg = iod->sgt.sgl; - int dma_len = sg_dma_len(sg); - u64 dma_addr = sg_dma_address(sg); - int offset = dma_addr & (NVME_CTRL_PAGE_SIZE - 1); + unsigned int length = blk_rq_payload_bytes(req); + struct blk_dma_iter iter; + dma_addr_t prp1_dma, prp2_dma = 0; + unsigned int prp_len, i; __le64 *prp_list; - dma_addr_t prp_dma; - int i; - length -= (NVME_CTRL_PAGE_SIZE - offset); - if (length <= 0) { - iod->first_dma = 0; + if (!blk_rq_dma_map_iter_start(req, dev->dev, &iod->dma_state, &iter)) + return iter.status; + + /* + * PRP1 always points to the start of the DMA transfers. + * + * This is the only PRP (except for the list entries) that could be + * non-aligned. + */ + prp1_dma = iter.addr; + prp_len = min(length, NVME_CTRL_PAGE_SIZE - + (iter.addr & (NVME_CTRL_PAGE_SIZE - 1))); + iod->total_len += prp_len; + iter.addr += prp_len; + iter.len -= prp_len; + length -= prp_len; + if (!length) goto done; - } - dma_len -= (NVME_CTRL_PAGE_SIZE - offset); - if (dma_len) { - dma_addr += (NVME_CTRL_PAGE_SIZE - offset); - } else { - sg = sg_next(sg); - dma_addr = sg_dma_address(sg); - dma_len = sg_dma_len(sg); + if (!iter.len) { + if (!blk_rq_dma_map_iter_next(req, dev->dev, &iod->dma_state, + &iter)) { + if (WARN_ON_ONCE(!iter.status)) + goto bad_sgl; + goto done; + } } + /* + * PRP2 is usually a list, but can point to data if all data to be + * transferred fits into PRP1 + PRP2: + */ if (length <= NVME_CTRL_PAGE_SIZE) { - iod->first_dma = dma_addr; + prp2_dma = iter.addr; + iod->total_len += length; goto done; } @@ -614,58 +693,83 @@ static blk_status_t nvme_pci_setup_prps(struct nvme_dev *dev, iod->large_descriptors = true; prp_list = dma_pool_alloc(nvme_dma_pool(dev, iod), GFP_ATOMIC, - &prp_dma); - if (!prp_list) - return BLK_STS_RESOURCE; + &prp2_dma); + if (!prp_list) { + iter.status = BLK_STS_RESOURCE; + goto done; + } iod->descriptors[iod->nr_descriptors++] = prp_list; - iod->first_dma = prp_dma; + i = 0; for (;;) { + prp_list[i++] = cpu_to_le64(iter.addr); + prp_len = min(length, NVME_CTRL_PAGE_SIZE); + if (WARN_ON_ONCE(iter.len < prp_len)) + goto bad_sgl; + + iod->total_len += prp_len; + iter.addr += prp_len; + iter.len -= prp_len; + length -= prp_len; + if (!length) + break; + + if (iter.len == 0) { + if (!blk_rq_dma_map_iter_next(req, dev->dev, + &iod->dma_state, &iter)) { + if (WARN_ON_ONCE(!iter.status)) + goto bad_sgl; + goto done; + } + } + + /* + * If we've filled the entire descriptor, allocate a new that is + * pointed to be the last entry in the previous PRP list. To + * accommodate for that move the last actual entry to the new + * descriptor. + */ if (i == NVME_CTRL_PAGE_SIZE >> 3) { __le64 *old_prp_list = prp_list; + dma_addr_t prp_list_dma; prp_list = dma_pool_alloc(dev->prp_page_pool, - GFP_ATOMIC, &prp_dma); - if (!prp_list) - goto free_prps; + GFP_ATOMIC, &prp_list_dma); + if (!prp_list) { + iter.status = BLK_STS_RESOURCE; + goto done; + } iod->descriptors[iod->nr_descriptors++] = prp_list; + prp_list[0] = old_prp_list[i - 1]; - old_prp_list[i - 1] = cpu_to_le64(prp_dma); + old_prp_list[i - 1] = cpu_to_le64(prp_list_dma); i = 1; } - prp_list[i++] = cpu_to_le64(dma_addr); - dma_len -= NVME_CTRL_PAGE_SIZE; - dma_addr += NVME_CTRL_PAGE_SIZE; - length -= NVME_CTRL_PAGE_SIZE; - if (length <= 0) - break; - if (dma_len > 0) - continue; - if (unlikely(dma_len < 0)) - goto bad_sgl; - sg = sg_next(sg); - dma_addr = sg_dma_address(sg); - dma_len = sg_dma_len(sg); } + done: - cmnd->dptr.prp1 = cpu_to_le64(sg_dma_address(iod->sgt.sgl)); - cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma); - return BLK_STS_OK; -free_prps: - nvme_free_descriptors(dev, req); - return BLK_STS_RESOURCE; + /* + * nvme_unmap_data uses the DPT field in the SQE to tear down the + * mapping, so initialize it even for failures. + */ + cmnd->dptr.prp1 = cpu_to_le64(prp1_dma); + cmnd->dptr.prp2 = cpu_to_le64(prp2_dma); + if (unlikely(iter.status)) + nvme_unmap_data(dev, req); + return iter.status; + bad_sgl: - WARN(DO_ONCE(nvme_print_sgl, iod->sgt.sgl, iod->sgt.nents), - "Invalid SGL for payload:%d nents:%d\n", - blk_rq_payload_bytes(req), iod->sgt.nents); + dev_err_once(dev->dev, + "Incorrectly formed request for payload:%d nents:%d\n", + blk_rq_payload_bytes(req), blk_rq_nr_phys_segments(req)); return BLK_STS_IOERR; } static void nvme_pci_sgl_set_data(struct nvme_sgl_desc *sge, - struct scatterlist *sg) + struct blk_dma_iter *iter) { - sge->addr = cpu_to_le64(sg_dma_address(sg)); - sge->length = cpu_to_le32(sg_dma_len(sg)); + sge->addr = cpu_to_le64(iter->addr); + sge->length = cpu_to_le32(iter->len); sge->type = NVME_SGL_FMT_DATA_DESC << 4; } @@ -681,17 +785,21 @@ static blk_status_t nvme_pci_setup_sgls(struct nvme_dev *dev, struct request *req, struct nvme_rw_command *cmd) { struct nvme_iod *iod = blk_mq_rq_to_pdu(req); + unsigned int entries = blk_rq_nr_phys_segments(req); struct nvme_sgl_desc *sg_list; - struct scatterlist *sg = iod->sgt.sgl; - unsigned int entries = iod->sgt.nents; + struct blk_dma_iter iter; dma_addr_t sgl_dma; - int i = 0; + unsigned int mapped = 0; /* setting the transfer type as SGL */ cmd->flags = NVME_CMD_SGL_METABUF; - if (entries == 1) { - nvme_pci_sgl_set_data(&cmd->dptr.sgl, sg); + if (!blk_rq_dma_map_iter_start(req, dev->dev, &iod->dma_state, &iter)) + return iter.status; + + if (entries == 1 || blk_rq_dma_map_coalesce(&iod->dma_state)) { + nvme_pci_sgl_set_data(&cmd->dptr.sgl, &iter); + iod->total_len += iter.len; return BLK_STS_OK; } @@ -702,110 +810,30 @@ static blk_status_t nvme_pci_setup_sgls(struct nvme_dev *dev, if (!sg_list) return BLK_STS_RESOURCE; iod->descriptors[iod->nr_descriptors++] = sg_list; - iod->first_dma = sgl_dma; - nvme_pci_sgl_set_seg(&cmd->dptr.sgl, sgl_dma, entries); do { - nvme_pci_sgl_set_data(&sg_list[i++], sg); - sg = sg_next(sg); - } while (--entries > 0); - - return BLK_STS_OK; -} - -static blk_status_t nvme_setup_prp_simple(struct nvme_dev *dev, - struct request *req, struct nvme_rw_command *cmnd, - struct bio_vec *bv) -{ - struct nvme_iod *iod = blk_mq_rq_to_pdu(req); - unsigned int offset = bv->bv_offset & (NVME_CTRL_PAGE_SIZE - 1); - unsigned int first_prp_len = NVME_CTRL_PAGE_SIZE - offset; - - iod->first_dma = dma_map_bvec(dev->dev, bv, rq_dma_dir(req), 0); - if (dma_mapping_error(dev->dev, iod->first_dma)) - return BLK_STS_RESOURCE; - iod->dma_len = bv->bv_len; - - cmnd->dptr.prp1 = cpu_to_le64(iod->first_dma); - if (bv->bv_len > first_prp_len) - cmnd->dptr.prp2 = cpu_to_le64(iod->first_dma + first_prp_len); - else - cmnd->dptr.prp2 = 0; - return BLK_STS_OK; -} - -static blk_status_t nvme_setup_sgl_simple(struct nvme_dev *dev, - struct request *req, struct nvme_rw_command *cmnd, - struct bio_vec *bv) -{ - struct nvme_iod *iod = blk_mq_rq_to_pdu(req); + if (WARN_ON_ONCE(mapped == entries)) { + iter.status = BLK_STS_IOERR; + break; + } + nvme_pci_sgl_set_data(&sg_list[mapped++], &iter); + iod->total_len += iter.len; + } while (blk_rq_dma_map_iter_next(req, dev->dev, &iod->dma_state, + &iter)); - iod->first_dma = dma_map_bvec(dev->dev, bv, rq_dma_dir(req), 0); - if (dma_mapping_error(dev->dev, iod->first_dma)) - return BLK_STS_RESOURCE; - iod->dma_len = bv->bv_len; + nvme_pci_sgl_set_seg(&cmd->dptr.sgl, sgl_dma, mapped); - cmnd->flags = NVME_CMD_SGL_METABUF; - cmnd->dptr.sgl.addr = cpu_to_le64(iod->first_dma); - cmnd->dptr.sgl.length = cpu_to_le32(iod->dma_len); - cmnd->dptr.sgl.type = NVME_SGL_FMT_DATA_DESC << 4; - return BLK_STS_OK; + if (unlikely(iter.status)) + nvme_free_sgls(dev, req); + return iter.status; } static blk_status_t nvme_map_data(struct nvme_dev *dev, struct request *req, struct nvme_command *cmnd) { - struct nvme_iod *iod = blk_mq_rq_to_pdu(req); - blk_status_t ret = BLK_STS_RESOURCE; - int rc; - - if (blk_rq_nr_phys_segments(req) == 1) { - struct nvme_queue *nvmeq = req->mq_hctx->driver_data; - struct bio_vec bv = req_bvec(req); - - if (!is_pci_p2pdma_page(bv.bv_page)) { - if ((bv.bv_offset & (NVME_CTRL_PAGE_SIZE - 1)) + - bv.bv_len <= NVME_CTRL_PAGE_SIZE * 2) - return nvme_setup_prp_simple(dev, req, - &cmnd->rw, &bv); - - if (nvmeq->qid && sgl_threshold && - nvme_ctrl_sgl_supported(&dev->ctrl)) - return nvme_setup_sgl_simple(dev, req, - &cmnd->rw, &bv); - } - } - - iod->dma_len = 0; - iod->sgt.sgl = mempool_alloc(dev->iod_mempool, GFP_ATOMIC); - if (!iod->sgt.sgl) - return BLK_STS_RESOURCE; - sg_init_table(iod->sgt.sgl, blk_rq_nr_phys_segments(req)); - iod->sgt.orig_nents = blk_rq_map_sg(req->q, req, iod->sgt.sgl); - if (!iod->sgt.orig_nents) - goto out_free_sg; - - rc = dma_map_sgtable(dev->dev, &iod->sgt, rq_dma_dir(req), - DMA_ATTR_NO_WARN); - if (rc) { - if (rc == -EREMOTEIO) - ret = BLK_STS_TARGET; - goto out_free_sg; - } - - if (nvme_pci_use_sgls(dev, req, iod->sgt.nents)) - ret = nvme_pci_setup_sgls(dev, req, &cmnd->rw); - else - ret = nvme_pci_setup_prps(dev, req, &cmnd->rw); - if (ret != BLK_STS_OK) - goto out_unmap_sg; - return BLK_STS_OK; - -out_unmap_sg: - dma_unmap_sgtable(dev->dev, &iod->sgt, rq_dma_dir(req), 0); -out_free_sg: - mempool_free(iod->sgt.sgl, dev->iod_mempool); - return ret; + if (nvme_pci_use_sgls(dev, req, blk_rq_nr_phys_segments(req))) + return nvme_pci_setup_sgls(dev, req, &cmnd->rw); + return nvme_pci_setup_prps(dev, req, &cmnd->rw); } static blk_status_t nvme_map_metadata(struct nvme_dev *dev, struct request *req, @@ -829,7 +857,7 @@ static blk_status_t nvme_prep_rq(struct nvme_dev *dev, struct request *req) iod->aborted = false; iod->nr_descriptors = 0; iod->large_descriptors = false; - iod->sgt.nents = 0; + iod->total_len = 0; ret = nvme_setup_cmd(req->q->queuedata, req); if (ret) -- 2.46.2