From 7f73eac3a7137eabfb0c005c7ba55eb7994b9673 Mon Sep 17 00:00:00 2001 From: Logan Gunthorpe Date: Mon, 12 Aug 2019 11:30:43 -0600 Subject: PCI/P2PDMA: Introduce pci_p2pdma_unmap_sg() Add pci_p2pdma_unmap_sg() to the two places that call pci_p2pdma_map_sg(). This is a prep patch to introduce correct mappings for p2pdma transactions that go through the root complex. Link: https://lore.kernel.org/r/20190730163545.4915-10-logang@deltatee.com Link: https://lore.kernel.org/r/20190812173048.9186-10-logang@deltatee.com Signed-off-by: Logan Gunthorpe Signed-off-by: Bjorn Helgaas Reviewed-by: Christoph Hellwig --- drivers/pci/p2pdma.c | 18 +++++++++++++++++- 1 file changed, 17 insertions(+), 1 deletion(-) (limited to 'drivers/pci') diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index 94fbacbcbbd0..1eec7a5ec27e 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -800,7 +800,8 @@ EXPORT_SYMBOL_GPL(pci_p2pmem_publish); * @dir: DMA direction * @attrs: DMA attributes passed to dma_map_sg() (if called) * - * Scatterlists mapped with this function should not be unmapped in any way. + * Scatterlists mapped with this function should be unmapped using + * pci_p2pdma_unmap_sg_attrs(). * * Returns the number of SG entries mapped or 0 on error. */ @@ -834,6 +835,21 @@ int pci_p2pdma_map_sg_attrs(struct device *dev, struct scatterlist *sg, } EXPORT_SYMBOL_GPL(pci_p2pdma_map_sg_attrs); +/** + * pci_p2pdma_unmap_sg - unmap a PCI peer-to-peer scatterlist that was + * mapped with pci_p2pdma_map_sg() + * @dev: device doing the DMA request + * @sg: scatter list to map + * @nents: number of elements returned by pci_p2pdma_map_sg() + * @dir: DMA direction + * @attrs: DMA attributes passed to dma_unmap_sg() (if called) + */ +void pci_p2pdma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, + int nents, enum dma_data_direction dir, unsigned long attrs) +{ +} +EXPORT_SYMBOL_GPL(pci_p2pdma_unmap_sg_attrs); + /** * pci_p2pdma_enable_store - parse a configfs/sysfs attribute store * to enable p2pdma -- cgit v1.2.3-59-g8ed1b