From 6c9c6d6301287e369a754d628230fa6e50cdb74b Mon Sep 17 00:00:00 2001 From: Shuah Khan Date: Mon, 8 Oct 2012 11:08:06 -0600 Subject: dma-debug: New interfaces to debug dma mapping errors Add dma-debug interface debug_dma_mapping_error() to debug drivers that fail to check dma mapping errors on addresses returned by dma_map_single() and dma_map_page() interfaces. This interface clears a flag set by debug_dma_map_page() to indicate that dma_mapping_error() has been called by the driver. When driver does unmap, debug_dma_unmap() checks the flag and if this flag is still set, prints warning message that includes call trace that leads up to the unmap. This interface can be called from dma_mapping_error() routines to enable dma mapping error check debugging. Tested: Intel iommu and swiotlb (iommu=soft) on x86-64 with CONFIG_DMA_API_DEBUG enabled and disabled. Signed-off-by: Shuah Khan Reviewed-by: Konrad Rzeszutek Wilk Signed-off-by: Joerg Roedel --- Documentation/DMA-API.txt | 12 ++++++++++++ 1 file changed, 12 insertions(+) (limited to 'Documentation/DMA-API.txt') diff --git a/Documentation/DMA-API.txt b/Documentation/DMA-API.txt index 66bd97a95f10..78a6c569d204 100644 --- a/Documentation/DMA-API.txt +++ b/Documentation/DMA-API.txt @@ -678,3 +678,15 @@ out of dma_debug_entries. These entries are preallocated at boot. The number of preallocated entries is defined per architecture. If it is too low for you boot with 'dma_debug_entries=' to overwrite the architectural default. + +void debug_dmap_mapping_error(struct device *dev, dma_addr_t dma_addr); + +dma-debug interface debug_dma_mapping_error() to debug drivers that fail +to check dma mapping errors on addresses returned by dma_map_single() and +dma_map_page() interfaces. This interface clears a flag set by +debug_dma_map_page() to indicate that dma_mapping_error() has been called by +the driver. When driver does unmap, debug_dma_unmap() checks the flag and if +this flag is still set, prints warning message that includes call trace that +leads up to the unmap. This interface can be called from dma_mapping_error() +routines to enable dma mapping error check debugging. + -- cgit v1.2.3-59-g8ed1b