diff options
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/pci/p2pdma.c | 44 |
1 files changed, 37 insertions, 7 deletions
diff --git a/drivers/pci/p2pdma.c b/drivers/pci/p2pdma.c index 4e8bc457e29a..5d2538aa0778 100644 --- a/drivers/pci/p2pdma.c +++ b/drivers/pci/p2pdma.c @@ -10,6 +10,7 @@ #define pr_fmt(fmt) "pci-p2pdma: " fmt #include <linux/ctype.h> +#include <linux/dma-map-ops.h> #include <linux/pci-p2pdma.h> #include <linux/module.h> #include <linux/slab.h> @@ -20,13 +21,6 @@ #include <linux/seq_buf.h> #include <linux/xarray.h> -enum pci_p2pdma_map_type { - PCI_P2PDMA_MAP_UNKNOWN = 0, - PCI_P2PDMA_MAP_NOT_SUPPORTED, - PCI_P2PDMA_MAP_BUS_ADDR, - PCI_P2PDMA_MAP_THRU_HOST_BRIDGE, -}; - struct pci_p2pdma { struct gen_pool *pool; bool p2pmem_published; @@ -945,6 +939,42 @@ void pci_p2pdma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, EXPORT_SYMBOL_GPL(pci_p2pdma_unmap_sg_attrs); /** + * pci_p2pdma_map_segment - map an sg segment determining the mapping type + * @state: State structure that should be declared outside of the for_each_sg() + * loop and initialized to zero. + * @dev: DMA device that's doing the mapping operation + * @sg: scatterlist segment to map + * + * This is a helper to be used by non-IOMMU dma_map_sg() implementations where + * the sg segment is the same for the page_link and the dma_address. + * + * Attempt to map a single segment in an SGL with the PCI bus address. + * The segment must point to a PCI P2PDMA page and thus must be + * wrapped in a is_pci_p2pdma_page(sg_page(sg)) check. + * + * Returns the type of mapping used and maps the page if the type is + * PCI_P2PDMA_MAP_BUS_ADDR. + */ +enum pci_p2pdma_map_type +pci_p2pdma_map_segment(struct pci_p2pdma_map_state *state, struct device *dev, + struct scatterlist *sg) +{ + if (state->pgmap != sg_page(sg)->pgmap) { + state->pgmap = sg_page(sg)->pgmap; + state->map = pci_p2pdma_map_type(state->pgmap, dev); + state->bus_off = to_p2p_pgmap(state->pgmap)->bus_offset; + } + + if (state->map == PCI_P2PDMA_MAP_BUS_ADDR) { + sg->dma_address = sg_phys(sg) + state->bus_off; + sg_dma_len(sg) = sg->length; + sg_dma_mark_bus_address(sg); + } + + return state->map; +} + +/** * pci_p2pdma_enable_store - parse a configfs/sysfs attribute store * to enable p2pdma * @page: contents of the value to be stored |