[PATCH v6 2/8] dma-mapping: replace set_arch_dma_coherent_ops with arch_setup_dma_ops

Will Deacon
2014-12-01T16:57:08Z

set_arch_dma_coherent_ops is called from of_dma_configure in order to
swizzle the architectural dma-mapping functions over to a cache-coherent
implementation. This is currently implemented only for ARM.

In anticipation of re-using this mechanism for IOMMU-backed dma-mapping
ops too, this patch replaces the function with a broader
arch_setup_dma_ops callback which will be extended in future.

Acked-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>
Tested-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Will Deacon <will.deacon@arm.com>
---
arch/arm/include/asm/dma-mapping.h | 8 ++++----
drivers/of/platform.c | 31 +++++++++++++------------------
include/linux/dma-mapping.h | 7 ++-----
3 files changed, 19 insertions(+), 27 deletions(-)

diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 85738b200023..dc3420e77758 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -121,12 +121,12 @@ static inline unsigned long dma_max_pfn(struct device *dev)
}
#define dma_max_pfn(dev) dma_max_pfn(dev)

-static inline int set_arch_dma_coherent_ops(struct device *dev)
+static inline void arch_setup_dma_ops(struct device *dev, bool coherent)
{
- set_dma_ops(dev, &arm_coherent_dma_ops);
- return 0;
+ if (coherent)
+ set_dma_ops(dev, &arm_coherent_dma_ops);
}
-#define set_arch_dma_coherent_ops(dev) set_arch_dma_coherent_ops(dev)
+#define arch_setup_dma_ops arch_setup_dma_ops

static inline dma_addr_t phys_to_dma(struct device *dev, phys_addr_t paddr)
{
diff --git a/drivers/of/platform.c b/drivers/of/platform.c
index 3b64d0bf5bba..ff1f4e9afccb 100644
--- a/drivers/of/platform.c
+++ b/drivers/of/platform.c
@@ -164,6 +164,8 @@ static void of_dma_configure(struct device *dev)
{
u64 dma_addr, paddr, size;
int ret;
+ bool coherent;
+ unsigned long offset;

/*
* Set default dma-mask to 32 bit. Drivers are expected to setup
@@ -178,28 +180,21 @@ static void of_dma_configure(struct device *dev)
if (!dev->dma_mask)
dev->dma_mask = &dev->coherent_dma_mask;

- /*
- * if dma-coherent property exist, call arch hook to setup
- * dma coherent operations.
- */
- if (of_dma_is_coherent(dev->of_node)) {
- set_arch_dma_coherent_ops(dev);
- dev_dbg(dev, "device is dma coherent\n");
- }
-
- /*
- * if dma-ranges property doesn't exist - just return else
- * setup the dma offset
- */
ret = of_dma_get_range(dev->of_node, &dma_addr, &paddr, &size);
if (ret < 0) {
- dev_dbg(dev, "no dma range information to setup\n");
- return;
+ dma_addr = offset = 0;
+ size = dev->coherent_dma_mask;
+ } else {
+ offset = PFN_DOWN(paddr - dma_addr);
+ dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", dev->dma_pfn_offset);
}
+ dev->dma_pfn_offset = offset;
+
+ coherent = of_dma_is_coherent(dev->of_node);
+ dev_dbg(dev, "device is%sdma coherent\n",
+ coherent ? " " : " not ");

- /* DMA ranges found. Calculate and set dma_pfn_offset */
- dev->dma_pfn_offset = PFN_DOWN(paddr - dma_addr);
- dev_dbg(dev, "dma_pfn_offset(%#08lx)\n", dev->dma_pfn_offset);
+ arch_setup_dma_ops(dev, coherent);
}

/**
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index d5d388160f42..8a1560f95d4a 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -129,11 +129,8 @@ static inline int dma_coerce_mask_and_coherent(struct device *dev, u64 mask)

extern u64 dma_get_required_mask(struct device *dev);

-#ifndef set_arch_dma_coherent_ops
-static inline int set_arch_dma_coherent_ops(struct device *dev)
-{
- return 0;
-}
+#ifndef arch_setup_dma_ops
+static inline void arch_setup_dma_ops(struct device *dev, bool coherent) { }
#endif

static inline unsigned int dma_get_max_seg_size(struct device *dev)
--
2.1.1