| Message ID | 20210909032528.24517-1-wanglu@dapustor.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Bjorn Helgaas |
| Headers | show |
| Series | PCI/P2PDMA: fix the wrong dma address calculation when map sg | expand |
On 2021-09-08 9:25 p.m., Wang Lu wrote: > 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@dapustor.com> Thanks, yes I believe my math was wrong here. It was never tested on any machine that has a non-zero bus-offset. Reviewed-by: Logan Gunthorpe <logang@deltatee.com>
On Thu, Sep 09, 2021 at 11:25:28AM +0800, Wang Lu wrote: > 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@dapustor.com> Applied with Logan's reviewed-by to pci/p2pdma for v5.16, thanks! I fixed the subject line and commit log for you to follow the usual conventions. > --- > 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 > > >
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; }
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@dapustor.com> --- drivers/pci/p2pdma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)