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| author | Joerg Roedel <jroedel@suse.de> | 2019-02-07 12:59:13 +0100 |
|---|---|---|
| committer | Michael S. Tsirkin <mst@redhat.com> | 2019-03-06 17:18:50 +0100 |
| commit | abe420bfae528c92bd8cc5ecb62dc95672b1fd6f (patch) | |
| tree | 54603461fce846d9f72f3e3934cc2f96f3dd5d0c | |
| parent | Linux 5.0 (diff) | |
| download | linux-abe420bfae528c92bd8cc5ecb62dc95672b1fd6f.tar.xz linux-abe420bfae528c92bd8cc5ecb62dc95672b1fd6f.zip | |
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 <konrad.wilk@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
| -rw-r--r-- | include/linux/swiotlb.h | 5 | ||||
| -rw-r--r-- | kernel/dma/swiotlb.c | 5 |
2 files changed, 10 insertions, 0 deletions
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index 7c007ed7505f..d3980aeed4a0 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 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; +} |