[PATCH v8 01/19] arm: make SWIOTLB available

From: Stefano Stabellini
Date: Thu Oct 17 2013 - 13:47:05 EST


IOMMU_HELPER is needed because SWIOTLB calls iommu_is_span_boundary,
provided by lib/iommu_helper.c.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
CC: will.deacon@xxxxxxx
CC: linux@xxxxxxxxxxxxxxxx


Changes in v8:
- use __phys_to_pfn and __pfn_to_phys.

Changes in v7:
- dma_mark_clean: empty implementation;
- in dma_capable use coherent_dma_mask if dma_mask hasn't been
allocated.

Changes in v6:
- check for dev->dma_mask being NULL in dma_capable.

Changes in v5:
- implement dma_mark_clean using dmac_flush_range.

Changes in v3:
- dma_capable: do not treat dma_mask as a limit;
- remove SWIOTLB dependency on NEED_SG_DMA_LENGTH.
---
arch/arm/Kconfig | 6 +++++
arch/arm/include/asm/dma-mapping.h | 37 ++++++++++++++++++++++++++++++++++++
2 files changed, 43 insertions(+), 0 deletions(-)

diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index ba412e0..c0bfb33 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -1832,6 +1832,12 @@ config CC_STACKPROTECTOR
neutralized via a kernel panic.
This feature requires gcc version 4.2 or above.

+config SWIOTLB
+ def_bool y
+
+config IOMMU_HELPER
+ def_bool SWIOTLB
+
config XEN_DOM0
def_bool y
depends on XEN
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 5b579b9..01b5a3d 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -10,6 +10,7 @@

#include <asm-generic/dma-coherent.h>
#include <asm/memory.h>
+#include <asm/cacheflush.h>

#define DMA_ERROR_CODE (~0)
extern struct dma_map_ops arm_dma_ops;
@@ -86,6 +87,42 @@ static inline dma_addr_t virt_to_dma(struct device *dev, void *addr)
}
#endif

+static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
+{
+ unsigned int offset = paddr & ~PAGE_MASK;
+ return pfn_to_dma(dev, __phys_to_pfn(paddr)) + offset;
+}
+
+static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t dev_addr)
+{
+ unsigned int offset = dev_addr & ~PAGE_MASK;
+ return __pfn_to_phys(dma_to_pfn(dev, dev_addr)) + offset;
+}
+
+static inline bool dma_capable(struct device *dev, dma_addr_t addr, size_t size)
+{
+ u64 limit, mask;
+
+ if (dev->dma_mask)
+ mask = *dev->dma_mask;
+ else
+ mask = dev->coherent_dma_mask;
+
+ if (mask == 0)
+ return 0;
+
+ limit = (mask + 1) & ~mask;
+ if (limit && size > limit)
+ return 0;
+
+ if ((addr | (addr + size - 1)) & ~mask)
+ return 0;
+
+ return 1;
+}
+
+static inline void dma_mark_clean(void *addr, size_t size) { }
+
/*
* DMA errors are defined by all-bits-set in the DMA address.
*/
--
1.7.2.5

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