From 4ca8d95ce1e71995052e81f1854a23803ca48b73 Mon Sep 17 00:00:00 2001 From: Alexander Sowarka Date: Sun, 28 Aug 2022 21:30:20 +0200 Subject: [PATCH] nvme: Fix multipage prp-list The nvme driver falsely assumed that the last entry on a page of the prp-list always points to the next page of the prp-list. This potentially can lead to the illegal creation of pages on the prp-list with only a single entry. This change now ensures that splitting the prp-list into multiple pages, behaves now as required by the NVME-Spec. Related to this, also the size of the memory allocation is adjusted accordingly. Signed-off-by: Alexander Sowarka --- drivers/nvme/nvme.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/drivers/nvme/nvme.c b/drivers/nvme/nvme.c index a305305..31cf700 100644 --- a/drivers/nvme/nvme.c +++ b/drivers/nvme/nvme.c @@ -72,7 +72,7 @@ static int nvme_setup_prps(struct nvme_dev *dev, u64 *prp2, } nprps = DIV_ROUND_UP(length, page_size); - num_pages = DIV_ROUND_UP(nprps, prps_per_page); + num_pages = DIV_ROUND_UP(nprps - 1, prps_per_page - 1); if (nprps > dev->prp_entry_num) { free(dev->prp_pool); @@ -85,13 +85,13 @@ static int nvme_setup_prps(struct nvme_dev *dev, u64 *prp2, printf("Error: malloc prp_pool fail\n"); return -ENOMEM; } - dev->prp_entry_num = prps_per_page * num_pages; + dev->prp_entry_num = num_pages * (prps_per_page - 1) + 1; } prp_pool = dev->prp_pool; i = 0; while (nprps) { - if (i == ((page_size >> 3) - 1)) { + if ((i == (prps_per_page - 1)) && nprps > 1) { *(prp_pool + i) = cpu_to_le64((ulong)prp_pool + page_size); i = 0; @@ -104,7 +104,7 @@ static int nvme_setup_prps(struct nvme_dev *dev, u64 *prp2, *prp2 = (ulong)dev->prp_pool; flush_dcache_range((ulong)dev->prp_pool, (ulong)dev->prp_pool + - dev->prp_entry_num * sizeof(u64)); + num_pages * page_size); return 0; } -- 2.7.4