Commit 150745b4 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-debug: remove DMA_API_DEBUG_SG 



The scatterlist validity checks are pretty simple and cheap, perform them
unconditionally.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
parent 9d4f645a

kernel/dma/Kconfig

+0 −17
Original line number Diff line number Diff line
@@ -260,23 +260,6 @@ config DMA_API_DEBUG 


	  If unsure, say N.



config DMA_API_DEBUG_SG

	bool "Debug DMA scatter-gather usage"

	default y

	depends on DMA_API_DEBUG

	help

	  Perform extra checking that callers of dma_map_sg() have respected the

	  appropriate segment length/boundary limits for the given device when

	  preparing DMA scatterlists.



	  This is particularly likely to have been overlooked in cases where the

	  dma_map_sg() API is used for general bulk mapping of pages rather than

	  preparing literal scatter-gather descriptors, where there is a risk of

	  unexpected behaviour from DMA API implementations if the scatterlist

	  is technically out-of-spec.



	  If unsure, say N.



config DMA_MAP_BENCHMARK

	bool "Enable benchmarking of streaming DMA mapping"

	depends on DEBUG_FS

kernel/dma/debug.c

+0 −2
Original line number Diff line number Diff line
@@ -1163,7 +1163,6 @@ static void check_sync(struct device *dev, 


static void check_sg_segment(struct device *dev, struct scatterlist *sg)

{

#ifdef CONFIG_DMA_API_DEBUG_SG

	unsigned int max_seg = dma_get_max_seg_size(dev);

	u64 start, end, boundary = dma_get_seg_boundary(dev);
@@ -1184,7 +1183,6 @@ static void check_sg_segment(struct device *dev, struct scatterlist *sg) 
	if ((start ^ end) & ~boundary)

		err_printk(dev, NULL, "mapping sg segment across boundary [start=0x%016llx] [end=0x%016llx] [boundary=0x%016llx]\n",

			   start, end, boundary);

#endif

}



void debug_dma_map_single(struct device *dev, const void *addr,