[RFC PATCH v2] arm DMA: Fix allocation from CMA for coherent DMA
From: Lorenzo Nava <hidden>
Date: 2015-05-26 18:55:45
Also in:
lkml
Subsystem:
arm port, the rest · Maintainers:
Russell King, Linus Torvalds
This patch allows the use of CMA for DMA coherent memory allocation. At the moment if "is_coherent" is set to true the allocation can't use the CMA, which I think is not the desired behaviour. Changes in v2: correct __arm_dma_free() according to __dma_alloc() allocation --- arch/arm/mm/dma-mapping.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 7e7583d..15643b9 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c@@ -645,9 +645,9 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, size = PAGE_ALIGN(size); want_vaddr = !dma_get_attr(DMA_ATTR_NO_KERNEL_MAPPING, attrs); - if (is_coherent || nommu()) + if (nommu()) addr = __alloc_simple_buffer(dev, size, gfp, &page); - else if (!(gfp & __GFP_WAIT)) + else if (!is_coherent && !(gfp & __GFP_WAIT)) addr = __alloc_from_pool(size, &page); else if (!dev_get_cma_area(dev)) addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller, want_vaddr);
@@ -735,7 +735,7 @@ static void __arm_dma_free(struct device *dev, size_t size, void *cpu_addr, size = PAGE_ALIGN(size); - if (is_coherent || nommu()) { + if (nommu()) { __dma_free_buffer(page, size); } else if (__free_from_pool(cpu_addr, size)) { return;
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1.7.10.4