Re: [PATCH] arm: dma-mapping: fix compilation error when CONFIG_MMU is not present

From: Marek Szyprowski
Date: Mon Oct 20 2014 - 03:43:11 EST


Hello,

On 2014-10-19 17:59, Stefan Hengelein wrote:
When CONFIG_MMU is not present, the variable 'atomic_pool' and the
function '__in_atomic_pool' are undeclared but used in part of the
code. Therefore, the compilation breaks.
Now, they are defined to dummy values when CONFIG_MMU is undefined.

This error was found with vampyr.

Frankly, those variables are used only when CONFIG_MMU or
CONFIG_ARM_DMA_USE_IOMMU are set. The latter imho makes only sense
together with CONFIG_MMU, so the issue reported here doesn't really
happen in real world.

Signed-off-by: Stefan Hengelein <stefan.hengelein@xxxxxx>
---
arch/arm/mm/dma-mapping.c | 2 ++
1 file changed, 2 insertions(+)

diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index c245d90..7d04cf7 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -573,12 +573,14 @@ static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot)
#else /* !CONFIG_MMU */
#define nommu() 1
+#define atomic_pool 0
#define __get_dma_pgprot(attrs, prot) __pgprot(0)
#define __alloc_remap_buffer(dev, size, gfp, prot, ret, c) NULL
#define __alloc_from_pool(size, ret_page) NULL
#define __alloc_from_contiguous(dev, size, prot, ret, c) NULL
#define __free_from_pool(cpu_addr, size) 0
+#define __in_atomic_pool(start, size) 0
#define __free_from_contiguous(dev, page, cpu_addr, size) do { } while (0)
#define __dma_free_remap(cpu_addr, size) do { } while (0)

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland

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