diff options
Diffstat (limited to 'kernel/dma')
| -rw-r--r-- | kernel/dma/direct.c | 11 | ||||
| -rw-r--r-- | kernel/dma/mapping.c | 14 | ||||
| -rw-r--r-- | kernel/dma/swiotlb.c | 14 |
3 files changed, 39 insertions, 0 deletions
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 7ff807f2121c..fcdb23e8d2fc 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -393,3 +393,14 @@ int dma_direct_supported(struct device *dev, u64 mask) */ return mask >= __phys_to_dma(dev, min_mask); } + +size_t dma_direct_max_mapping_size(struct device *dev) +{ + size_t size = SIZE_MAX; + + /* If SWIOTLB is active, use its maximum mapping size */ + if (is_swiotlb_active()) + size = swiotlb_max_mapping_size(dev); + + return size; +} diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index ef2aba503467..c000906348c9 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -360,3 +360,17 @@ void dma_cache_sync(struct device *dev, void *vaddr, size_t size, ops->cache_sync(dev, vaddr, size, dir); } EXPORT_SYMBOL(dma_cache_sync); + +size_t dma_max_mapping_size(struct device *dev) +{ + const struct dma_map_ops *ops = get_dma_ops(dev); + size_t size = SIZE_MAX; + + if (dma_is_direct(ops)) + size = dma_direct_max_mapping_size(dev); + else if (ops && ops->max_mapping_size) + size = ops->max_mapping_size(dev); + + return size; +} +EXPORT_SYMBOL_GPL(dma_max_mapping_size); diff --git a/kernel/dma/swiotlb.c b/kernel/dma/swiotlb.c index a9ad02d4d84e..9f5851064aea 100644 --- a/kernel/dma/swiotlb.c +++ b/kernel/dma/swiotlb.c @@ -666,6 +666,20 @@ bool swiotlb_map(struct device *dev, phys_addr_t *phys, dma_addr_t *dma_addr, return true; } +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; +} + #ifdef CONFIG_DEBUG_FS static int __init swiotlb_create_debugfs(void) |