On Tue, Jul 02, 2019 at 11:35:44AM -0600, Logan Gunthorpe wrote:
> Drivers that use dma_virt_ops were meant to be rejected when testing
> compatibility for P2PDMA.
>
> This check got inadvertantly dropped in one of the later versions of the
> original patchset, so add it back.
>
> Fixes: 52916982af48 ("PCI/P2PDMA: Support peer-to-peer memory")
> Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx>
Applied to pci/peer-to-peer for v5.3, thanks!
> ---
> drivers/pci/p2pdma.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c
> index a4994aa3acc0..ab48babdf214 100644
> --- a/drivers/pci/p2pdma.c
> +++ b/drivers/pci/p2pdma.c
> @@ -487,6 +487,14 @@ int pci_p2pdma_distance_many(struct pci_dev *provider, struct device **clients,
> return -1;
>
> for (i = 0; i < num_clients; i++) {
> + if (IS_ENABLED(CONFIG_DMA_VIRT_OPS) &&
> + clients[i]->dma_ops == &dma_virt_ops) {
> + if (verbose)
> + dev_warn(clients[i],
> + "cannot be used for peer-to-peer DMA because the driver makes use of dma_virt_ops\n");
> + return -1;
> + }
> +
> pci_client = find_parent_pci_dev(clients[i]);
> if (!pci_client) {
> if (verbose)
> @@ -765,7 +773,7 @@ int pci_p2pdma_map_sg(struct device *dev, struct scatterlist *sg, int nents,
> * p2pdma mappings are not compatible with devices that use
> * dma_virt_ops. If the upper layers do the right thing
> * this should never happen because it will be prevented
> - * by the check in pci_p2pdma_add_client()
> + * by the check in pci_p2pdma_distance_many()
> */
> if (WARN_ON_ONCE(IS_ENABLED(CONFIG_DMA_VIRT_OPS) &&
> dev->dma_ops == &dma_virt_ops))
> --
> 2.20.1
>
