diff options
| -rw-r--r-- | include/linux/swiotlb.h | 6 | ||||
| -rw-r--r-- | kernel/dma/swiotlb.c | 9 |
2 files changed, 15 insertions, 0 deletions
diff --git a/include/linux/swiotlb.h b/include/linux/swiotlb.h index d3980aeed4a0..29bc3a203283 100644 --- a/include/linux/swiotlb.h +++ b/include/linux/swiotlb.h @@ -77,6 +77,7 @@ bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr, void __init swiotlb_exit(void); unsigned int swiotlb_max_segment(void); size_t swiotlb_max_mapping_size(struct device *dev); +bool is_swiotlb_active(void); #else #define swiotlb_force SWIOTLB_NO_FORCE static inline bool is_swiotlb_buffer(phys_addr_t paddr) @@ -100,6 +101,11 @@ static inline size_t swiotlb_max_mapping_size(struct device *dev) { return SIZE_MAX; } + +static inline bool is_swiotlb_active(void) +{ + return false; +} #endif /* CONFIG_SWIOTLB */ extern void swiotlb_print_info(void); diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index 9cb21259cb0b..c873f9cc2146 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -667,3 +667,12 @@ size_t swiotlb_max_mapping_size(struct device *dev) { return ((size_t)1 << IO_TLB_SHIFT) * IO_TLB_SEGSIZE; } + +bool is_swiotlb_active(void) +{ + /* + * When SWIOTLB is initialized, even if io_tlb_start points to physical + * address zero, io_tlb_end surely doesn't. + */ + return io_tlb_end != 0; +} |