From abe420bfae528c92bd8cc5ecb62dc95672b1fd6f Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 7 Feb 2019 12:59:13 +0100 Subject: 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 --- kernel/dma/swiotlb.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'kernel') diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 1fb6fd68b9c7..9cb21259cb0b 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; +} -- cgit v1.2.3-71-gd317