From 133d624b1cee16906134e92d5befb843b58bcf31 Mon Sep 17 00:00:00 2001 From: Joerg Roedel Date: Thu, 7 Feb 2019 12:59:15 +0100 Subject: dma: Introduce dma_max_mapping_size() The function returns the maximum size that can be mapped using DMA-API functions. The patch also adds the implementation for direct DMA and a new dma_map_ops pointer so that other implementations can expose their limit. 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/direct.c | 11 +++++++++++ kernel/dma/mapping.c | 14 ++++++++++++++ 2 files changed, 25 insertions(+) (limited to 'kernel') diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c index 355d16acee6d..6310ad01f915 100644 --- a/kernel/dma/direct.c +++ b/kernel/dma/direct.c @@ -380,3 +380,14 @@ 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 a11006b6d8e8..5753008ab286 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -357,3 +357,17 @@ 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); -- cgit v1.2.3-58-ga151