From abe420bfae528c92bd8cc5ecb62dc95672b1fd6f Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 7 Feb 2019 12:59:13 +0100 Subject: [PATCH] swiotlb: Introduce swiotlb_max_mapping_size() The function returns the maximum size that can be remapped by the SWIOTLB implementation. This function will be later exposed to users through the DMA-API. Cc: stable@vger.kernel.org Reviewed-by: Konrad Rzeszutek Wilk Reviewed-by: Christoph Hellwig Signed-off-by: Joerg Roedel Signed-off-by: Michael S. Tsirkin --- include/linux/swiotlb.h | 5 +++++ kernel/dma/swiotlb.c | 5 +++++ 2 files changed, 10 insertions(+) diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 7c007ed..d3980ae 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -76,6 +76,7 @@ bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr, size_t size, enum dma_data_direction dir, unsigned long attrs); void __init swiotlb_exit(void); unsigned int swiotlb_max_segment(void); +size_t swiotlb_max_mapping_size(struct device *dev); #else #define swiotlb_force SWIOTLB_NO_FORCE static inline bool is_swiotlb_buffer(phys_addr_t paddr) @@ -95,6 +96,10 @@ static inline unsigned int swiotlb_max_segment(void) { return 0; } +static inline size_t swiotlb_max_mapping_size(struct device *dev) +{ + return SIZE_MAX; +} #endif /* CONFIG_SWIOTLB */ extern void swiotlb_print_info(void); diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 1fb6fd6..9cb2125 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -662,3 +662,8 @@ swiotlb_dma_supported(struct device *hwdev, u64 mask) { return __phys_to_dma(hwdev, io_tlb_end - 1) <= mask; } + +size_t swiotlb_max_mapping_size(struct device *dev) +{ + return ((size_t)1 << IO_TLB_SHIFT) * IO_TLB_SEGSIZE; +} -- 2.7.4