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authorJoerg Roedel <jroedel@suse.de>2019-02-07 12:59:13 +0100
committerMichael S. Tsirkin <mst@redhat.com>2019-03-06 11:18:50 -0500
commitabe420bfae528c92bd8cc5ecb62dc95672b1fd6f (patch)
tree54603461fce846d9f72f3e3934cc2f96f3dd5d0c
parent1c163f4c7b3f621efff9b28a47abb36f7378d783 (diff)
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.h5
-rw-r--r--kernel/dma/swiotlb.c5
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;
+}