Commit 2c8ed1b9 authored by Christoph Hellwig's avatar Christoph Hellwig
Browse files

dma-direct: add a CONFIG_ARCH_HAS_DMA_ALLOC symbol 



Instead of using arch_dma_alloc if none of the generic coherent
allocators are used, require the architectures to explicitly opt into
providing it.  This will used to deal with the case of m68knommu and
coldfire where we can't do any coherent allocations whatsoever, and
also makes it clear that arch_dma_alloc is a last resort.

Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
Reviewed-by: default avatarRobin Murphy <robin.murphy@arm.com>
Reviewed-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
Tested-by: default avatarGreg Ungerer <gerg@linux-m68k.org>
parent da323d46

arch/arm/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ config ARM 
	select ARCH_HAS_CPU_FINALIZE_INIT if MMU

	select ARCH_HAS_CURRENT_STACK_POINTER

	select ARCH_HAS_DEBUG_VIRTUAL if MMU

	select ARCH_HAS_DMA_ALLOC if MMU

	select ARCH_HAS_DMA_WRITE_COMBINE if !ARM_DMA_MEM_BUFFERABLE

	select ARCH_HAS_ELF_RANDOMIZE

	select ARCH_HAS_FORTIFY_SOURCE

arch/m68k/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -6,6 +6,7 @@ config M68K 
	select ARCH_HAS_BINFMT_FLAT

	select ARCH_HAS_CPU_FINALIZE_INIT if MMU

	select ARCH_HAS_CURRENT_STACK_POINTER

	select ARCH_HAS_DMA_ALLOC if !MMU || COLDFIRE

	select ARCH_HAS_DMA_PREP_COHERENT if HAS_DMA && MMU && !COLDFIRE

	select ARCH_HAS_SYNC_DMA_FOR_DEVICE if HAS_DMA

	select ARCH_HAVE_NMI_SAFE_CMPXCHG if RMW_INSNS

arch/parisc/Kconfig

+1 −0
Original line number Diff line number Diff line
@@ -8,6 +8,7 @@ config PARISC 
	select HAVE_FUNCTION_GRAPH_TRACER

	select HAVE_SYSCALL_TRACEPOINTS

	select ARCH_WANT_FRAME_POINTERS

	select ARCH_HAS_DMA_ALLOC if PA11

	select ARCH_HAS_ELF_RANDOMIZE

	select ARCH_HAS_STRICT_KERNEL_RWX

	select ARCH_HAS_STRICT_MODULE_RWX

kernel/dma/Kconfig

+9 −0
Original line number Diff line number Diff line
@@ -144,6 +144,15 @@ config DMA_DIRECT_REMAP 
	select DMA_COHERENT_POOL

	select DMA_NONCOHERENT_MMAP



#

# Fallback to arch code for DMA allocations.  This should eventually go away.

#

config ARCH_HAS_DMA_ALLOC

	depends on !ARCH_HAS_DMA_SET_UNCACHED

	depends on !DMA_DIRECT_REMAP

	depends on !DMA_GLOBAL_POOL

	bool



config DMA_CMA

	bool "DMA Contiguous Memory Allocator"

	depends on HAVE_DMA_CONTIGUOUS && CMA

kernel/dma/direct.c

+2 −10
Original line number Diff line number Diff line
@@ -220,13 +220,7 @@ void *dma_direct_alloc(struct device *dev, size_t size, 
		return dma_direct_alloc_no_mapping(dev, size, dma_handle, gfp);



	if (!dev_is_dma_coherent(dev)) {

		/*

		 * Fallback to the arch handler if it exists.  This should

		 * eventually go away.

		 */

		if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&

		    !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&

		    !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) &&

		if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_ALLOC) &&

		    !is_swiotlb_for_alloc(dev))

			return arch_dma_alloc(dev, size, dma_handle, gfp,

					      attrs);
@@ -330,9 +324,7 @@ void dma_direct_free(struct device *dev, size_t size, 
		return;

	}



	if (!IS_ENABLED(CONFIG_ARCH_HAS_DMA_SET_UNCACHED) &&

	    !IS_ENABLED(CONFIG_DMA_DIRECT_REMAP) &&

	    !IS_ENABLED(CONFIG_DMA_GLOBAL_POOL) &&

	if (IS_ENABLED(CONFIG_ARCH_HAS_DMA_ALLOC) &&

	    !dev_is_dma_coherent(dev) &&

	    !is_swiotlb_for_alloc(dev)) {

		arch_dma_free(dev, size, cpu_addr, dma_addr, attrs);