[PATCH] PCI/P2PDMA: fix the wrong dma address calculation when map sg

From: Wang Lu
Date: Wed Sep 08 2021 - 23:27:23 EST


The bus offset is bus address - physical address,
so the calculation in __pci_p2pdma_map_sg should be:
bus address = physical address + bus offset.

Signed-off-by: Wang Lu <wanglu@xxxxxxxxxxxx>
---
drivers/pci/p2pdma.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
index 50cdde3e9a8b..327882638b30 100644
--- a/drivers/pci/p2pdma.c
+++ b/drivers/pci/p2pdma.c
@@ -874,7 +874,7 @@ static int __pci_p2pdma_map_sg(struct pci_p2pdma_pagemap *p2p_pgmap,
int i;

for_each_sg(sg, s, nents, i) {
- s->dma_address = sg_phys(s) - p2p_pgmap->bus_offset;
+ s->dma_address = sg_phys(s) + p2p_pgmap->bus_offset;
sg_dma_len(s) = s->length;
}

--
2.17.1