CMA has been enabled unconditionally on all ARMv6+ systems to solve the long standing issue of double kernel mappings for all dma coherent buffers. This however created a dependency on CONFIG_EXPERIMENTAL for the whole ARM architecture what should be really avoided. This patch removes this dependency and lets one use old, well-tested dma-mapping implementation also on ARMv6+ systems without the need to use EXPERIMENTAL stuff.
Reported-by: Russell King linux@arm.linux.org.uk Signed-off-by: Marek Szyprowski m.szyprowski@samsung.com --- arch/arm/Kconfig | 1 - arch/arm/mm/dma-mapping.c | 10 ++++------ 2 files changed, 4 insertions(+), 7 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig index 5e76013..ca7354f 100644 --- a/arch/arm/Kconfig +++ b/arch/arm/Kconfig @@ -7,7 +7,6 @@ config ARM select HAVE_IDE if PCI || ISA || PCMCIA select HAVE_DMA_ATTRS select HAVE_DMA_CONTIGUOUS if (CPU_V6 || CPU_V6K || CPU_V7) - select CMA if (CPU_V6 || CPU_V6K || CPU_V7) select HAVE_MEMBLOCK select RTC_LIB select SYS_SUPPORTS_APM_EMULATION diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index ea6b431..106c4c0 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -268,10 +268,8 @@ static int __init consistent_init(void) unsigned long base = consistent_base; unsigned long num_ptes = (CONSISTENT_END - base) >> PMD_SHIFT;
-#ifndef CONFIG_ARM_DMA_USE_IOMMU - if (cpu_architecture() >= CPU_ARCH_ARMv6) + if (IS_ENABLED(CONFIG_CMA) && !IS_ENABLED(CONFIG_ARM_DMA_USE_IOMMU)) return 0; -#endif
consistent_pte = kmalloc(num_ptes * sizeof(pte_t), GFP_KERNEL); if (!consistent_pte) { @@ -342,7 +340,7 @@ static int __init coherent_init(void) struct page *page; void *ptr;
- if (cpu_architecture() < CPU_ARCH_ARMv6) + if (!IS_ENABLED(CONFIG_CMA)) return 0;
ptr = __alloc_from_contiguous(NULL, size, prot, &page); @@ -704,7 +702,7 @@ static void *__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
if (arch_is_coherent() || nommu()) addr = __alloc_simple_buffer(dev, size, gfp, &page); - else if (cpu_architecture() < CPU_ARCH_ARMv6) + else if (!IS_ENABLED(CONFIG_CMA)) addr = __alloc_remap_buffer(dev, size, gfp, prot, &page, caller); else if (gfp & GFP_ATOMIC) addr = __alloc_from_pool(dev, size, &page, caller); @@ -773,7 +771,7 @@ void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
if (arch_is_coherent() || nommu()) { __dma_free_buffer(page, size); - } else if (cpu_architecture() < CPU_ARCH_ARMv6) { + } else if (!IS_ENABLED(CONFIG_CMA)) { __dma_free_remap(cpu_addr, size); __dma_free_buffer(page, size); } else {