From 1755b32516bb42123b0030080226d6079999621d Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Sat, 10 May 2025 05:49:41 +0200 Subject: [PATCH] nvme-pci: remove struct nvme_descriptor There is no real point in having a union of two pointer types here, just use a void pointer as we mix and match types between the arms of the union between the allocation and freeing side already. Also rename the nr_allocations field to nr_descriptors to better describe what it does. Signed-off-by: Christoph Hellwig [leon: ported forward to include metadata SGL support] Signed-off-by: Leon Romanovsky Reviewed-by: Keith Busch Reviewed-by: Kanchan Joshi --- drivers/nvme/host/pci.c | 57 +++++++++++++++++------------------------ 1 file changed, 24 insertions(+), 33 deletions(-) diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c index 51430f5e6a66..f332b4ee7809 100644 --- a/drivers/nvme/host/pci.c +++ b/drivers/nvme/host/pci.c @@ -44,7 +44,7 @@ #define NVME_MAX_KB_SZ 8192 #define NVME_MAX_SEGS 128 #define NVME_MAX_META_SEGS 15 -#define NVME_MAX_NR_ALLOCATIONS 5 +#define NVME_MAX_NR_DESCRIPTORS 5 static int use_threaded_interrupts; module_param(use_threaded_interrupts, int, 0444); @@ -225,11 +225,6 @@ struct nvme_queue { struct completion delete_done; }; -union nvme_descriptor { - struct nvme_sgl_desc *sg_list; - __le64 *prp_list; -}; - /* bits for iod->flags */ enum nvme_iod_flags { /* this command has been aborted by the timeout handler */ @@ -238,23 +233,19 @@ enum nvme_iod_flags { /* * The nvme_iod describes the data in an I/O. - * - * The sg pointer contains the list of PRP/SGL chunk allocations in addition - * to the actual struct scatterlist. */ struct nvme_iod { struct nvme_request req; struct nvme_command cmd; u8 flags; - s8 nr_allocations; /* PRP list pool allocations. 0 means small - pool in use */ + s8 nr_descriptors; unsigned int dma_len; /* length of single DMA segment mapping */ dma_addr_t first_dma; dma_addr_t meta_dma; struct sg_table sgt; struct sg_table meta_sgt; - union nvme_descriptor meta_list; - union nvme_descriptor list[NVME_MAX_NR_ALLOCATIONS]; + struct nvme_sgl_desc *meta_descriptor; + void *descriptors[NVME_MAX_NR_DESCRIPTORS]; }; static inline unsigned int nvme_dbbuf_size(struct nvme_dev *dev) @@ -607,8 +598,8 @@ static void nvme_free_prps(struct nvme_queue *nvmeq, struct request *req) dma_addr_t dma_addr = iod->first_dma; int i; - for (i = 0; i < iod->nr_allocations; i++) { - __le64 *prp_list = iod->list[i].prp_list; + for (i = 0; i < iod->nr_descriptors; i++) { + __le64 *prp_list = iod->descriptors[i]; dma_addr_t next_dma_addr = le64_to_cpu(prp_list[last_prp]); dma_pool_free(nvmeq->prp_pools.large, prp_list, dma_addr); @@ -631,11 +622,11 @@ static void nvme_unmap_data(struct nvme_dev *dev, struct nvme_queue *nvmeq, dma_unmap_sgtable(dev->dev, &iod->sgt, rq_dma_dir(req), 0); - if (iod->nr_allocations == 0) - dma_pool_free(nvmeq->prp_pools.small, iod->list[0].sg_list, + if (iod->nr_descriptors == 0) + dma_pool_free(nvmeq->prp_pools.small, iod->descriptors[0], iod->first_dma); - else if (iod->nr_allocations == 1) - dma_pool_free(nvmeq->prp_pools.large, iod->list[0].sg_list, + else if (iod->nr_descriptors == 1) + dma_pool_free(nvmeq->prp_pools.large, iod->descriptors[0], iod->first_dma); else nvme_free_prps(nvmeq, req); @@ -693,18 +684,18 @@ static blk_status_t nvme_pci_setup_prps(struct nvme_queue *nvmeq, nprps = DIV_ROUND_UP(length, NVME_CTRL_PAGE_SIZE); if (nprps <= (256 / 8)) { pool = nvmeq->prp_pools.small; - iod->nr_allocations = 0; + iod->nr_descriptors = 0; } else { pool = nvmeq->prp_pools.large; - iod->nr_allocations = 1; + iod->nr_descriptors = 1; } prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma); if (!prp_list) { - iod->nr_allocations = -1; + iod->nr_descriptors = -1; return BLK_STS_RESOURCE; } - iod->list[0].prp_list = prp_list; + iod->descriptors[0] = prp_list; iod->first_dma = prp_dma; i = 0; for (;;) { @@ -713,7 +704,7 @@ static blk_status_t nvme_pci_setup_prps(struct nvme_queue *nvmeq, prp_list = dma_pool_alloc(pool, GFP_ATOMIC, &prp_dma); if (!prp_list) goto free_prps; - iod->list[iod->nr_allocations++].prp_list = prp_list; + 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); i = 1; @@ -783,19 +774,19 @@ static blk_status_t nvme_pci_setup_sgls(struct nvme_queue *nvmeq, if (entries <= (256 / sizeof(struct nvme_sgl_desc))) { pool = nvmeq->prp_pools.small; - iod->nr_allocations = 0; + iod->nr_descriptors = 0; } else { pool = nvmeq->prp_pools.large; - iod->nr_allocations = 1; + iod->nr_descriptors = 1; } sg_list = dma_pool_alloc(pool, GFP_ATOMIC, &sgl_dma); if (!sg_list) { - iod->nr_allocations = -1; + iod->nr_descriptors = -1; return BLK_STS_RESOURCE; } - iod->list[0].sg_list = sg_list; + iod->descriptors[0] = sg_list; iod->first_dma = sgl_dma; nvme_pci_sgl_set_seg(&cmd->dptr.sgl, sgl_dma, entries); @@ -935,7 +926,7 @@ static blk_status_t nvme_pci_setup_meta_sgls(struct nvme_dev *dev, goto out_unmap_sg; entries = iod->meta_sgt.nents; - iod->meta_list.sg_list = sg_list; + iod->meta_descriptor = sg_list; iod->meta_dma = sgl_dma; cmnd->flags = NVME_CMD_SGL_METASEG; @@ -991,7 +982,7 @@ static blk_status_t nvme_prep_rq(struct nvme_dev *dev, struct request *req) blk_status_t ret; iod->flags = 0; - iod->nr_allocations = -1; + iod->nr_descriptors = -1; iod->sgt.nents = 0; iod->meta_sgt.nents = 0; @@ -1117,8 +1108,8 @@ static __always_inline void nvme_unmap_metadata(struct nvme_dev *dev, return; } - dma_pool_free(nvmeq->prp_pools.small, iod->meta_list.sg_list, - iod->meta_dma); + dma_pool_free(nvmeq->prp_pools.small, iod->meta_descriptor, + iod->meta_dma); dma_unmap_sgtable(dev->dev, &iod->meta_sgt, rq_dma_dir(req), 0); mempool_free(iod->meta_sgt.sgl, dev->iod_meta_mempool); } @@ -3842,7 +3833,7 @@ static int __init nvme_init(void) BUILD_BUG_ON(IRQ_AFFINITY_MAX_SETS < 2); BUILD_BUG_ON(NVME_MAX_SEGS > SGES_PER_PAGE); BUILD_BUG_ON(sizeof(struct scatterlist) * NVME_MAX_SEGS > PAGE_SIZE); - BUILD_BUG_ON(nvme_pci_npages_prp() > NVME_MAX_NR_ALLOCATIONS); + BUILD_BUG_ON(nvme_pci_npages_prp() > NVME_MAX_NR_DESCRIPTORS); return pci_register_driver(&nvme_driver); } -- 2.25.1