[PATCH 7/8] ARM: integrate CMA with dma-mapping subsystem
From: Marek Szyprowski
Date: Tue Jul 05 2011 - 03:42:09 EST
This patch adds support for CMA to dma-mapping subsystem for ARM
architecture. By default a global CMA area is used, but specific devices
are allowed to have their private memory areas if required (they can be
created with dma_declare_contiguous() function during board
initialization).
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
arch/arm/Kconfig | 1 +
arch/arm/include/asm/device.h | 3 ++
arch/arm/include/asm/dma-mapping.h | 20 ++++++++++++++
arch/arm/mm/dma-mapping.c | 51 +++++++++++++++++++++++++++--------
arch/arm/mm/init.c | 3 ++
5 files changed, 66 insertions(+), 12 deletions(-)
diff --git a/arch/arm/Kconfig b/arch/arm/Kconfig
index 9adc278..3cca8cc 100644
--- a/arch/arm/Kconfig
+++ b/arch/arm/Kconfig
@@ -3,6 +3,7 @@ config ARM
default y
select HAVE_AOUT
select HAVE_DMA_API_DEBUG
+ select HAVE_DMA_CONTIGUOUS
select HAVE_IDE
select HAVE_MEMBLOCK
select RTC_LIB
diff --git a/arch/arm/include/asm/device.h b/arch/arm/include/asm/device.h
index 9f390ce..942913e 100644
--- a/arch/arm/include/asm/device.h
+++ b/arch/arm/include/asm/device.h
@@ -10,6 +10,9 @@ struct dev_archdata {
#ifdef CONFIG_DMABOUNCE
struct dmabounce_device_info *dmabounce;
#endif
+#ifdef CONFIG_CMA
+ struct cma *cma_area;
+#endif
};
struct pdev_archdata {
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index 4fff837..a3e1e48c 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -6,6 +6,7 @@
#include <linux/mm_types.h>
#include <linux/scatterlist.h>
#include <linux/dma-debug.h>
+#include <linux/dma-contiguous.h>
#include <asm-generic/dma-coherent.h>
#include <asm/memory.h>
@@ -14,6 +15,25 @@
#error Please update to __arch_pfn_to_dma
#endif
+#ifdef CONFIG_CMA
+static inline struct cma *get_dev_cma_area(struct device *dev)
+{
+ if (dev->archdata.cma_area)
+ return dev->archdata.cma_area;
+ return dma_contiguous_default_area;
+}
+
+static inline void set_dev_cma_area(struct device *dev, struct cma *cma)
+{
+ dev->archdata.cma_area = cma;
+}
+#else
+static inline struct cma *get_dev_cma_area(struct device *dev)
+{
+ return NULL;
+}
+#endif
+
/*
* dma_to_pfn/pfn_to_dma/dma_to_virt/virt_to_dma are architecture private
* functions used internally by the DMA-mapping API to provide DMA
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 82a093c..1d4e916 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -17,6 +17,7 @@
#include <linux/init.h>
#include <linux/device.h>
#include <linux/dma-mapping.h>
+#include <linux/dma-contiguous.h>
#include <linux/highmem.h>
#include <asm/memory.h>
@@ -52,16 +53,35 @@ static u64 get_coherent_dma_mask(struct device *dev)
return mask;
}
+
+static struct page *__alloc_system_pages(size_t count, unsigned int order, gfp_t gfp)
+{
+ struct page *page, *p, *e;
+
+ page = alloc_pages(gfp, order);
+ if (!page)
+ return NULL;
+
+ /*
+ * Now split the huge page and free the excess pages
+ */
+ split_page(page, order);
+ for (p = page + count, e = page + (1 << order); p < e; p++)
+ __free_page(p);
+ return page;
+}
+
/*
* Allocate a DMA buffer for 'dev' of size 'size' using the
* specified gfp mask. Note that 'size' must be page aligned.
*/
static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gfp)
{
- unsigned long order = get_order(size);
- struct page *page, *p, *e;
+ struct page *page;
+ size_t count = size >> PAGE_SHIFT;
void *ptr;
u64 mask = get_coherent_dma_mask(dev);
+ unsigned long order = get_order(count << PAGE_SHIFT);
#ifdef CONFIG_DMA_API_DEBUG
u64 limit = (mask + 1) & ~mask;
@@ -78,16 +98,19 @@ static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gf
if (mask < 0xffffffffULL)
gfp |= GFP_DMA;
- page = alloc_pages(gfp, order);
- if (!page)
- return NULL;
+ /*
+ * First, try to allocate memory from contiguous area
+ */
+ page = dma_alloc_from_contiguous(dev, count, order);
/*
- * Now split the huge page and free the excess pages
+ * Fallback if contiguous alloc fails or is not available
*/
- split_page(page, order);
- for (p = page + (size >> PAGE_SHIFT), e = page + (1 << order); p < e; p++)
- __free_page(p);
+ if (!page)
+ page = __alloc_system_pages(count, order, gfp);
+
+ if (!page)
+ return NULL;
/*
* Ensure that the allocated pages are zeroed, and that any data
@@ -104,9 +127,13 @@ static struct page *__dma_alloc_buffer(struct device *dev, size_t size, gfp_t gf
/*
* Free a DMA buffer. 'size' must be page aligned.
*/
-static void __dma_free_buffer(struct page *page, size_t size)
+static void __dma_free_buffer(struct device *dev, struct page *page, size_t size)
{
- struct page *e = page + (size >> PAGE_SHIFT);
+ size_t count = size >> PAGE_SHIFT;
+ struct page *e = page + count;
+
+ if (dma_release_from_contiguous(dev, page, count))
+ return;
while (page < e) {
__free_page(page);
@@ -416,7 +443,7 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr
if (!arch_is_coherent())
__dma_free_remap(cpu_addr, size);
- __dma_free_buffer(pfn_to_page(dma_to_pfn(dev, handle)), size);
+ __dma_free_buffer(dev, pfn_to_page(dma_to_pfn(dev, handle)), size);
}
EXPORT_SYMBOL(dma_free_coherent);
diff --git a/arch/arm/mm/init.c b/arch/arm/mm/init.c
index c19571c..b2dfdeb 100644
--- a/arch/arm/mm/init.c
+++ b/arch/arm/mm/init.c
@@ -20,6 +20,7 @@
#include <linux/gfp.h>
#include <linux/memblock.h>
#include <linux/sort.h>
+#include <linux/dma-contiguous.h>
#include <asm/mach-types.h>
#include <asm/prom.h>
@@ -358,6 +359,8 @@ void __init arm_memblock_init(struct meminfo *mi, struct machine_desc *mdesc)
if (mdesc->reserve)
mdesc->reserve();
+ dma_contiguous_reserve();
+
memblock_analyze();
memblock_dump_all();
}
--
1.7.1.569.g6f426
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