From f69e342eec008e1bab772d3963c3dd9979293e13 Mon Sep 17 00:00:00 2001 From: Leon Romanovsky Date: Wed, 24 Jul 2024 21:04:48 +0300 Subject: [PATCH] dma-mapping: call ->unmap_page and ->unmap_sg unconditionally Almost all instances of the dma_map_ops ->map_page()/map_sg() methods implement ->unmap_page()/unmap_sg() too. The once instance which doesn't dma_dummy_ops which is used to fail the DMA mapping and thus there won't be any calls to ->unmap_page()/unmap_sg(). Remove the checks for ->unmap_page()/unmap_sg() and call them directly to create an interface that is symmetrical to ->map_page()/map_sg(). Signed-off-by: Leon Romanovsky Signed-off-by: Leon Romanovsky Reviewed-by: Robin Murphy Signed-off-by: Christoph Hellwig --- kernel/dma/dummy.c | 21 +++++++++++++++++++++ kernel/dma/mapping.c | 4 ++-- 2 files changed, 23 insertions(+), 2 deletions(-) diff --git a/kernel/dma/dummy.c b/kernel/dma/dummy.c index b492d59ac77e..92de80e5b057 100644 --- a/kernel/dma/dummy.c +++ b/kernel/dma/dummy.c @@ -17,6 +17,15 @@ static dma_addr_t dma_dummy_map_page(struct device *dev, struct page *page, { return DMA_MAPPING_ERROR; } +static void dma_dummy_unmap_page(struct device *dev, dma_addr_t dma_handle, + size_t size, enum dma_data_direction dir, unsigned long attrs) +{ + /* + * Dummy ops doesn't support map_page, so unmap_page should never be + * called. + */ + WARN_ON_ONCE(true); +} static int dma_dummy_map_sg(struct device *dev, struct scatterlist *sgl, int nelems, enum dma_data_direction dir, @@ -25,6 +34,16 @@ static int dma_dummy_map_sg(struct device *dev, struct scatterlist *sgl, return -EINVAL; } +static void dma_dummy_unmap_sg(struct device *dev, struct scatterlist *sgl, + int nelems, enum dma_data_direction dir, + unsigned long attrs) +{ + /* + * Dummy ops doesn't support map_sg, so unmap_sg should never be called. + */ + WARN_ON_ONCE(true); +} + static int dma_dummy_supported(struct device *hwdev, u64 mask) { return 0; @@ -33,6 +52,8 @@ static int dma_dummy_supported(struct device *hwdev, u64 mask) const struct dma_map_ops dma_dummy_ops = { .mmap = dma_dummy_mmap, .map_page = dma_dummy_map_page, + .unmap_page = dma_dummy_unmap_page, .map_sg = dma_dummy_map_sg, + .unmap_sg = dma_dummy_unmap_sg, .dma_supported = dma_dummy_supported, }; diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index b1c18058d55f..71416b156bb5 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -177,7 +177,7 @@ void dma_unmap_page_attrs(struct device *dev, dma_addr_t addr, size_t size, if (dma_map_direct(dev, ops) || arch_dma_unmap_page_direct(dev, addr + size)) dma_direct_unmap_page(dev, addr, size, dir, attrs); - else if (ops->unmap_page) + else ops->unmap_page(dev, addr, size, dir, attrs); debug_dma_unmap_page(dev, addr, size, dir); } @@ -291,7 +291,7 @@ void dma_unmap_sg_attrs(struct device *dev, struct scatterlist *sg, if (dma_map_direct(dev, ops) || arch_dma_unmap_sg_direct(dev, sg, nents)) dma_direct_unmap_sg(dev, sg, nents, dir, attrs); - else if (ops->unmap_sg) + else ops->unmap_sg(dev, sg, nents, dir, attrs); } EXPORT_SYMBOL(dma_unmap_sg_attrs);