[PATCH] common: dma-mapping: add support for generic dma_mmap_* calls
From: Marek Szyprowski
Date: Fri Jun 15 2012 - 02:19:13 EST
Commit 9adc5374 ('common: dma-mapping: introduce mmap method') added a
generic method for implementing mmap user call to dma_map_ops structure.
This patch converts ARM and PowerPC architectures (the only providers of
dma_mmap_coherent/dma_mmap_writecombine calls) to use this generic
dma_map_ops based call and adds a generic cross architecture
definition for dma_mmap_attrs, dma_mmap_coherent, dma_mmap_writecombine
functions.
The generic mmap virt_to_page-based fallback implementation is provided for
architectures which don't provide their own implementation for mmap method.
Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
Reviewed-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx>
---
Hello,
This patch is a continuation of my works on dma-mapping cleanup and
unification. Previous works (commit 58bca4a8fa ('Merge branch
'for-linus' of git://git.linaro.org/people/mszyprowski/linux-dma-mapping')
has been merged to v3.4-rc2. Now I've focuses on providing implementation
for all architectures so the drivers and some cross-architecture common
helpers (like for example videobuf2) can start using this new api.
I'm not 100% sure if the PowerPC changes are correct. The cases of
dma_iommu_ops and vio_dma_mapping_ops are a bit suspicious for me, but I
have no way to test and check if my changes works for that hardware.
Best regards
Marek Szyprowski
Samsung Poland R&D Center
---
arch/arm/include/asm/dma-mapping.h | 19 ---------------
arch/powerpc/include/asm/dma-mapping.h | 8 +++---
arch/powerpc/kernel/dma-iommu.c | 1 +
arch/powerpc/kernel/dma-swiotlb.c | 1 +
arch/powerpc/kernel/dma.c | 36 +++++++++++++++-------------
arch/powerpc/kernel/vio.c | 1 +
drivers/base/dma-mapping.c | 31 +++++++++++++++++++++++++
include/asm-generic/dma-coherent.h | 1 +
include/asm-generic/dma-mapping-common.h | 37 ++++++++++++++++++++++++++++++
9 files changed, 95 insertions(+), 40 deletions(-)
diff --git a/arch/arm/include/asm/dma-mapping.h b/arch/arm/include/asm/dma-mapping.h
index bbef15d..8645088 100644
--- a/arch/arm/include/asm/dma-mapping.h
+++ b/arch/arm/include/asm/dma-mapping.h
@@ -186,17 +186,6 @@ extern int arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size,
struct dma_attrs *attrs);
-#define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, NULL)
-
-static inline int dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
- void *cpu_addr, dma_addr_t dma_addr,
- size_t size, struct dma_attrs *attrs)
-{
- struct dma_map_ops *ops = get_dma_ops(dev);
- BUG_ON(!ops);
- return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
-}
-
static inline void *dma_alloc_writecombine(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag)
{
@@ -213,14 +202,6 @@ static inline void dma_free_writecombine(struct device *dev, size_t size,
return dma_free_attrs(dev, size, cpu_addr, dma_handle, &attrs);
}
-static inline int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
- void *cpu_addr, dma_addr_t dma_addr, size_t size)
-{
- DEFINE_DMA_ATTRS(attrs);
- dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
- return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, &attrs);
-}
-
/*
* This can be called during boot to increase the size of the consistent
* DMA region above it's default value of 2MB. It must be called before the
diff --git a/arch/powerpc/include/asm/dma-mapping.h b/arch/powerpc/include/asm/dma-mapping.h
index 62678e3..7816087 100644
--- a/arch/powerpc/include/asm/dma-mapping.h
+++ b/arch/powerpc/include/asm/dma-mapping.h
@@ -27,7 +27,10 @@ extern void *dma_direct_alloc_coherent(struct device *dev, size_t size,
extern void dma_direct_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle,
struct dma_attrs *attrs);
-
+extern int dma_direct_mmap_coherent(struct device *dev,
+ struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t handle,
+ size_t size, struct dma_attrs *attrs);
#ifdef CONFIG_NOT_COHERENT_CACHE
/*
@@ -207,11 +210,8 @@ static inline phys_addr_t dma_to_phys(struct device *dev, dma_addr_t daddr)
#define dma_alloc_noncoherent(d, s, h, f) dma_alloc_coherent(d, s, h, f)
#define dma_free_noncoherent(d, s, v, h) dma_free_coherent(d, s, v, h)
-extern int dma_mmap_coherent(struct device *, struct vm_area_struct *,
- void *, dma_addr_t, size_t);
#define ARCH_HAS_DMA_MMAP_COHERENT
-
static inline void dma_cache_sync(struct device *dev, void *vaddr, size_t size,
enum dma_data_direction direction)
{
diff --git a/arch/powerpc/kernel/dma-iommu.c b/arch/powerpc/kernel/dma-iommu.c
index bcfdcd2..2d7bb8c 100644
--- a/arch/powerpc/kernel/dma-iommu.c
+++ b/arch/powerpc/kernel/dma-iommu.c
@@ -109,6 +109,7 @@ static u64 dma_iommu_get_required_mask(struct device *dev)
struct dma_map_ops dma_iommu_ops = {
.alloc = dma_iommu_alloc_coherent,
.free = dma_iommu_free_coherent,
+ .mmap = dma_direct_mmap_coherent,
.map_sg = dma_iommu_map_sg,
.unmap_sg = dma_iommu_unmap_sg,
.dma_supported = dma_iommu_dma_supported,
diff --git a/arch/powerpc/kernel/dma-swiotlb.c b/arch/powerpc/kernel/dma-swiotlb.c
index 4ab88da..4694365 100644
--- a/arch/powerpc/kernel/dma-swiotlb.c
+++ b/arch/powerpc/kernel/dma-swiotlb.c
@@ -49,6 +49,7 @@ static u64 swiotlb_powerpc_get_required(struct device *dev)
struct dma_map_ops swiotlb_dma_ops = {
.alloc = dma_direct_alloc_coherent,
.free = dma_direct_free_coherent,
+ .mmap = dma_direct_mmap_coherent,
.map_sg = swiotlb_map_sg_attrs,
.unmap_sg = swiotlb_unmap_sg_attrs,
.dma_supported = swiotlb_dma_supported,
diff --git a/arch/powerpc/kernel/dma.c b/arch/powerpc/kernel/dma.c
index b1ec983..062bf20 100644
--- a/arch/powerpc/kernel/dma.c
+++ b/arch/powerpc/kernel/dma.c
@@ -65,6 +65,24 @@ void dma_direct_free_coherent(struct device *dev, size_t size,
#endif
}
+int dma_direct_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t handle, size_t size,
+ struct dma_attrs *attrs)
+{
+ unsigned long pfn;
+
+#ifdef CONFIG_NOT_COHERENT_CACHE
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+ pfn = __dma_get_coherent_pfn((unsigned long)cpu_addr);
+#else
+ pfn = page_to_pfn(virt_to_page(cpu_addr));
+#endif
+ return remap_pfn_range(vma, vma->vm_start,
+ pfn + vma->vm_pgoff,
+ vma->vm_end - vma->vm_start,
+ vma->vm_page_prot);
+}
+
static int dma_direct_map_sg(struct device *dev, struct scatterlist *sgl,
int nents, enum dma_data_direction direction,
struct dma_attrs *attrs)
@@ -154,6 +172,7 @@ static inline void dma_direct_sync_single(struct device *dev,
struct dma_map_ops dma_direct_ops = {
.alloc = dma_direct_alloc_coherent,
.free = dma_direct_free_coherent,
+ .mmap = dma_direct_mmap_coherent,
.map_sg = dma_direct_map_sg,
.unmap_sg = dma_direct_unmap_sg,
.dma_supported = dma_direct_dma_supported,
@@ -211,20 +230,3 @@ static int __init dma_init(void)
}
fs_initcall(dma_init);
-int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
- void *cpu_addr, dma_addr_t handle, size_t size)
-{
- unsigned long pfn;
-
-#ifdef CONFIG_NOT_COHERENT_CACHE
- vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
- pfn = __dma_get_coherent_pfn((unsigned long)cpu_addr);
-#else
- pfn = page_to_pfn(virt_to_page(cpu_addr));
-#endif
- return remap_pfn_range(vma, vma->vm_start,
- pfn + vma->vm_pgoff,
- vma->vm_end - vma->vm_start,
- vma->vm_page_prot);
-}
-EXPORT_SYMBOL_GPL(dma_mmap_coherent);
diff --git a/arch/powerpc/kernel/vio.c b/arch/powerpc/kernel/vio.c
index cb87301..dda3d9a 100644
--- a/arch/powerpc/kernel/vio.c
+++ b/arch/powerpc/kernel/vio.c
@@ -613,6 +613,7 @@ static u64 vio_dma_get_required_mask(struct device *dev)
struct dma_map_ops vio_dma_mapping_ops = {
.alloc = vio_dma_iommu_alloc_coherent,
.free = vio_dma_iommu_free_coherent,
+ .mmap = dma_direct_mmap_coherent,
.map_sg = vio_dma_iommu_map_sg,
.unmap_sg = vio_dma_iommu_unmap_sg,
.map_page = vio_dma_iommu_map_page,
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 6f3676f..db5db02 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -10,6 +10,7 @@
#include <linux/dma-mapping.h>
#include <linux/export.h>
#include <linux/gfp.h>
+#include <asm-generic/dma-coherent.h>
/*
* Managed DMA API
@@ -218,3 +219,33 @@ void dmam_release_declared_memory(struct device *dev)
EXPORT_SYMBOL(dmam_release_declared_memory);
#endif
+
+/*
+ * Create userspace mapping for the DMA-coherent memory.
+ */
+int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size)
+{
+ int ret = -ENXIO;
+#ifdef CONFIG_MMU
+ unsigned long user_count = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
+ unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
+ unsigned long pfn = page_to_pfn(virt_to_page(cpu_addr));
+ unsigned long off = vma->vm_pgoff;
+
+ vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+ if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
+ return ret;
+
+ if (off < count && user_count <= (count - off)) {
+ ret = remap_pfn_range(vma, vma->vm_start,
+ pfn + off,
+ user_count << PAGE_SHIFT,
+ vma->vm_page_prot);
+ }
+#endif /* CONFIG_MMU */
+
+ return ret;
+}
+EXPORT_SYMBOL(dma_common_mmap);
diff --git a/include/asm-generic/dma-coherent.h b/include/asm-generic/dma-coherent.h
index abfb268..2be8a2d 100644
--- a/include/asm-generic/dma-coherent.h
+++ b/include/asm-generic/dma-coherent.h
@@ -29,6 +29,7 @@ dma_mark_declared_memory_occupied(struct device *dev,
#else
#define dma_alloc_from_coherent(dev, size, handle, ret) (0)
#define dma_release_from_coherent(dev, order, vaddr) (0)
+#define dma_mmap_from_coherent(dev, vma, vaddr, order, ret) (0)
#endif
#endif
diff --git a/include/asm-generic/dma-mapping-common.h b/include/asm-generic/dma-mapping-common.h
index 2e248d8..9073aeb 100644
--- a/include/asm-generic/dma-mapping-common.h
+++ b/include/asm-generic/dma-mapping-common.h
@@ -176,4 +176,41 @@ dma_sync_sg_for_device(struct device *dev, struct scatterlist *sg,
#define dma_map_sg(d, s, n, r) dma_map_sg_attrs(d, s, n, r, NULL)
#define dma_unmap_sg(d, s, n, r) dma_unmap_sg_attrs(d, s, n, r, NULL)
+extern int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size);
+
+/**
+ * dma_mmap_attrs - map a coherent DMA allocation into user space
+ * @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
+ * @vma: vm_area_struct describing requested user mapping
+ * @cpu_addr: kernel CPU-view address returned from dma_alloc_attrs
+ * @handle: device-view address returned from dma_alloc_attrs
+ * @size: size of memory originally requested in dma_alloc_attrs
+ * @attrs: attributes of mapping properties requested in dma_alloc_attrs
+ *
+ * Map a coherent DMA buffer previously allocated by dma_alloc_attrs
+ * into user space. The coherent DMA buffer must not be freed by the
+ * driver until the user space mapping has been released.
+ */
+static inline int
+dma_mmap_attrs(struct device *dev, struct vm_area_struct *vma, void *cpu_addr,
+ dma_addr_t dma_addr, size_t size, struct dma_attrs *attrs)
+{
+ struct dma_map_ops *ops = get_dma_ops(dev);
+ BUG_ON(!ops);
+ if (ops->mmap)
+ return ops->mmap(dev, vma, cpu_addr, dma_addr, size, attrs);
+ return dma_common_mmap(dev, vma, cpu_addr, dma_addr, size);
+}
+
+#define dma_mmap_coherent(d, v, c, h, s) dma_mmap_attrs(d, v, c, h, s, NULL)
+
+static inline int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
+ void *cpu_addr, dma_addr_t dma_addr, size_t size)
+{
+ DEFINE_DMA_ATTRS(attrs);
+ dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
+ return dma_mmap_attrs(dev, vma, cpu_addr, dma_addr, size, &attrs);
+}
+
#endif
--
1.7.1.569.g6f426
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