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ARM: dma-mapping: remove unconditional dependency on CMA 

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>
This commit is contained in:
Marek Szyprowski 2012-05-30 10:48:29 +02:00
parent f8f5701bda
commit f1ae98da85
2 changed files with 4 additions and 7 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/arm/Kconfig
View File

@ -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

10
arch/arm/mm/dma-mapping.c
View File

@ -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 {