From: Will Davis <[email protected]> Implement 'map_resource' for the AMD IOMMU driver. Generalize the existing map_page implementation to operate on a physical address, and make both map_page and map_resource wrappers around that helper (and similiarly, for unmap_page and unmap_resource).
This allows a device to map another's resource, to enable peer-to-peer transactions. Signed-off-by: Will Davis <[email protected]> Reviewed-by: Terence Ripperda <[email protected]> Reviewed-by: John Hubbard <[email protected]> --- drivers/iommu/amd_iommu.c | 76 +++++++++++++++++++++++++++++++++++++++-------- 1 file changed, 63 insertions(+), 13 deletions(-) diff --git a/drivers/iommu/amd_iommu.c b/drivers/iommu/amd_iommu.c index e43d489..ca2dac6 100644 --- a/drivers/iommu/amd_iommu.c +++ b/drivers/iommu/amd_iommu.c @@ -503,6 +503,8 @@ DECLARE_STATS_COUNTER(cnt_map_single); DECLARE_STATS_COUNTER(cnt_unmap_single); DECLARE_STATS_COUNTER(cnt_map_sg); DECLARE_STATS_COUNTER(cnt_unmap_sg); +DECLARE_STATS_COUNTER(cnt_map_resource); +DECLARE_STATS_COUNTER(cnt_unmap_resource); DECLARE_STATS_COUNTER(cnt_alloc_coherent); DECLARE_STATS_COUNTER(cnt_free_coherent); DECLARE_STATS_COUNTER(cross_page); @@ -541,6 +543,8 @@ static void amd_iommu_stats_init(void) amd_iommu_stats_add(&cnt_unmap_single); amd_iommu_stats_add(&cnt_map_sg); amd_iommu_stats_add(&cnt_unmap_sg); + amd_iommu_stats_add(&cnt_map_resource); + amd_iommu_stats_add(&cnt_unmap_resource); amd_iommu_stats_add(&cnt_alloc_coherent); amd_iommu_stats_add(&cnt_free_coherent); amd_iommu_stats_add(&cross_page); @@ -2752,20 +2756,16 @@ static void __unmap_single(struct dma_ops_domain *dma_dom, } /* - * The exported map_single function for dma_ops. + * Wrapper function that contains code common to mapping a physical address + * range from a page or a resource. */ -static dma_addr_t map_page(struct device *dev, struct page *page, - unsigned long offset, size_t size, - enum dma_data_direction dir, - struct dma_attrs *attrs) +static dma_addr_t __map_phys(struct device *dev, phys_addr_t paddr, + size_t size, enum dma_data_direction dir) { unsigned long flags; struct protection_domain *domain; dma_addr_t addr; u64 dma_mask; - phys_addr_t paddr = page_to_phys(page) + offset; - - INC_STATS_COUNTER(cnt_map_single); domain = get_domain(dev); if (PTR_ERR(domain) == -EINVAL) @@ -2791,16 +2791,15 @@ out: } /* - * The exported unmap_single function for dma_ops. + * Wrapper function that contains code common to unmapping a physical address + * range from a page or a resource. */ -static void unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size, - enum dma_data_direction dir, struct dma_attrs *attrs) +static void __unmap_phys(struct device *dev, dma_addr_t dma_addr, size_t size, + enum dma_data_direction dir) { unsigned long flags; struct protection_domain *domain; - INC_STATS_COUNTER(cnt_unmap_single); - domain = get_domain(dev); if (IS_ERR(domain)) return; @@ -2815,6 +2814,55 @@ static void unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size, } /* + * The exported map_single function for dma_ops. + */ +static dma_addr_t map_page(struct device *dev, struct page *page, + unsigned long offset, size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + INC_STATS_COUNTER(cnt_map_single); + + return __map_phys(dev, page_to_phys(page) + offset, size, dir); +} + +/* + * The exported unmap_single function for dma_ops. + */ +static void unmap_page(struct device *dev, dma_addr_t dma_addr, size_t size, + enum dma_data_direction dir, struct dma_attrs *attrs) +{ + INC_STATS_COUNTER(cnt_unmap_single); + + __unmap_phys(dev, dma_addr, size, dir); +} + +/* + * The exported map_resource function for dma_ops. + */ +static dma_addr_t map_resource(struct device *dev, struct resource *res, + unsigned long offset, size_t size, + enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + INC_STATS_COUNTER(cnt_map_resource); + + return __map_phys(dev, res->start + offset, size, dir); +} + +/* + * The exported unmap_resource function for dma_ops. + */ +static void unmap_resource(struct device *dev, dma_addr_t dma_addr, + size_t size, enum dma_data_direction dir, + struct dma_attrs *attrs) +{ + INC_STATS_COUNTER(cnt_unmap_resource); + + __unmap_phys(dev, dma_addr, size, dir); +} + +/* * The exported map_sg function for dma_ops (handles scatter-gather * lists). */ @@ -3066,6 +3114,8 @@ static struct dma_map_ops amd_iommu_dma_ops = { .unmap_page = unmap_page, .map_sg = map_sg, .unmap_sg = unmap_sg, + .map_resource = map_resource, + .unmap_resource = unmap_resource, .dma_supported = amd_iommu_dma_supported, }; -- 2.4.0 _______________________________________________ iommu mailing list [email protected] https://lists.linuxfoundation.org/mailman/listinfo/iommu
