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authorChristoph Hellwig <hch@lst.de>2023-10-05 09:05:36 +0200
committerChristoph Hellwig <hch@lst.de>2023-10-22 16:38:54 +0200
commit2c8ed1b960fb97c82ede5afc974329bfdb457f5f (patch)
treee6ec8ae5530fa02461f8c2ba7ef2b0551d375576 /kernel
parentda323d4640704001f2287f729124e1cd9d5684d0 (diff)
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: 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>
Diffstat (limited to 'kernel')
-rw-r--r--kernel/dma/Kconfig9
-rw-r--r--kernel/dma/direct.c12
2 files changed, 11 insertions, 10 deletions
diff --git a/kernel/dma/Kconfig b/kernel/dma/Kconfig
index 4524db877eba..d62f5957f36b 100644
--- a/kernel/dma/Kconfig
+++ b/kernel/dma/Kconfig
@@ -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
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 9596ae1aa0da..c078090cd38e 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -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);