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dma-direct: add a CONFIG_ARCH_HAS_DMA_ALLOC symbol

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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: Christoph Hellwig <hch@lst.de>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Reviewed-by: Greg Ungerer <gerg@linux-m68k.org>
Tested-by: Greg Ungerer <gerg@linux-m68k.org>
This commit is contained in:
Christoph Hellwig 2023-10-05 09:05:36 +02:00
parent da323d4640
commit 2c8ed1b960
5 changed files with 14 additions and 10 deletions
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1
arch/arm/Kconfig
View file

@ -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

1
arch/m68k/Kconfig
View file

@ -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

1
arch/parisc/Kconfig
View file

@ -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

9
kernel/dma/Kconfig
View file

@ -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

12
kernel/dma/direct.c
View file

@ -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);