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ARM: dma-mapping: use alloc, mmap, free from dma_ops
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This patch converts dma_alloc/free/mmap_{coherent,writecombine}
functions to use generic alloc/free/mmap methods from dma_map_ops
structure. A new DMA_ATTR_WRITE_COMBINE DMA attribute have been
introduced to implement writecombine methods.

Signed-off-by: Marek Szyprowski <[email protected]>
Acked-by: Kyungmin Park <[email protected]>
Acked-by: Arnd Bergmann <[email protected]>
Tested-By: Subash Patel <[email protected]>
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@mszyprow
mszyprow committed May 21, 2012
1 parent 51fde34 commit f99d603
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Showing 3 changed files with 104 additions and 66 deletions.
3 changes: 3 additions & 0 deletions arch/arm/common/dmabounce.c
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Original file line number Diff line number Diff line change
Expand Up @@ -449,6 +449,9 @@ static int dmabounce_set_mask(struct device *dev, u64 dma_mask)
}

static struct dma_map_ops dmabounce_ops = {
.alloc = arm_dma_alloc,
.free = arm_dma_free,
.mmap = arm_dma_mmap,
.map_page = dmabounce_map_page,
.unmap_page = dmabounce_unmap_page,
.sync_single_for_cpu = dmabounce_sync_for_cpu,
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107 changes: 77 additions & 30 deletions arch/arm/include/asm/dma-mapping.h
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Original file line number Diff line number Diff line change
Expand Up @@ -5,6 +5,7 @@

#include <linux/mm_types.h>
#include <linux/scatterlist.h>
#include <linux/dma-attrs.h>
#include <linux/dma-debug.h>

#include <asm-generic/dma-coherent.h>
Expand Down Expand Up @@ -110,68 +111,115 @@ static inline void dma_free_noncoherent(struct device *dev, size_t size,
extern int dma_supported(struct device *dev, u64 mask);

/**
* dma_alloc_coherent - allocate consistent memory for DMA
* arm_dma_alloc - allocate consistent memory for DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @size: required memory size
* @handle: bus-specific DMA address
* @attrs: optinal attributes that specific mapping properties
*
* Allocate some uncached, unbuffered memory for a device for
* performing DMA. This function allocates pages, and will
* return the CPU-viewed address, and sets @handle to be the
* device-viewed address.
* Allocate some memory for a device for performing DMA. This function
* allocates pages, and will return the CPU-viewed address, and sets @handle
* to be the device-viewed address.
*/
extern void *dma_alloc_coherent(struct device *, size_t, dma_addr_t *, gfp_t);
extern void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
gfp_t gfp, struct dma_attrs *attrs);

#define dma_alloc_coherent(d, s, h, f) dma_alloc_attrs(d, s, h, f, NULL)

static inline void *dma_alloc_attrs(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag,
struct dma_attrs *attrs)
{
struct dma_map_ops *ops = get_dma_ops(dev);
void *cpu_addr;
BUG_ON(!ops);

cpu_addr = ops->alloc(dev, size, dma_handle, flag, attrs);
debug_dma_alloc_coherent(dev, size, *dma_handle, cpu_addr);
return cpu_addr;
}

/**
* dma_free_coherent - free memory allocated by dma_alloc_coherent
* arm_dma_free - free memory allocated by arm_dma_alloc
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @size: size of memory originally requested in dma_alloc_coherent
* @cpu_addr: CPU-view address returned from dma_alloc_coherent
* @handle: device-view address returned from dma_alloc_coherent
* @attrs: optinal attributes that specific mapping properties
*
* Free (and unmap) a DMA buffer previously allocated by
* dma_alloc_coherent().
* arm_dma_alloc().
*
* References to memory and mappings associated with cpu_addr/handle
* during and after this call executing are illegal.
*/
extern void dma_free_coherent(struct device *, size_t, void *, dma_addr_t);
extern void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t handle, struct dma_attrs *attrs);

#define dma_free_coherent(d, s, c, h) dma_free_attrs(d, s, c, h, NULL)

static inline void dma_free_attrs(struct device *dev, size_t size,
void *cpu_addr, dma_addr_t dma_handle,
struct dma_attrs *attrs)
{
struct dma_map_ops *ops = get_dma_ops(dev);
BUG_ON(!ops);

debug_dma_free_coherent(dev, size, cpu_addr, dma_handle);
ops->free(dev, size, cpu_addr, dma_handle, attrs);
}

/**
* dma_mmap_coherent - map a coherent DMA allocation into user space
* arm_dma_mmap - 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_coherent
* @handle: device-view address returned from dma_alloc_coherent
* @size: size of memory originally requested in dma_alloc_coherent
* @attrs: optinal attributes that specific mapping properties
*
* Map a coherent DMA buffer previously allocated by dma_alloc_coherent
* into user space. The coherent DMA buffer must not be freed by the
* driver until the user space mapping has been released.
*/
int dma_mmap_coherent(struct device *, struct vm_area_struct *,
void *, dma_addr_t, size_t);
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)

/**
* dma_alloc_writecombine - allocate writecombining memory for DMA
* @dev: valid struct device pointer, or NULL for ISA and EISA-like devices
* @size: required memory size
* @handle: bus-specific DMA address
*
* Allocate some uncached, buffered memory for a device for
* performing DMA. This function allocates pages, and will
* return the CPU-viewed address, and sets @handle to be the
* device-viewed address.
*/
extern void *dma_alloc_writecombine(struct device *, size_t, dma_addr_t *,
gfp_t);
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);
}

#define dma_free_writecombine(dev,size,cpu_addr,handle) \
dma_free_coherent(dev,size,cpu_addr,handle)
static inline void *dma_alloc_writecombine(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t flag)
{
DEFINE_DMA_ATTRS(attrs);
dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
return dma_alloc_attrs(dev, size, dma_handle, flag, &attrs);
}

int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
void *, dma_addr_t, size_t);
static inline void dma_free_writecombine(struct device *dev, size_t size,
void *cpu_addr, dma_addr_t dma_handle)
{
DEFINE_DMA_ATTRS(attrs);
dma_set_attr(DMA_ATTR_WRITE_COMBINE, &attrs);
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
Expand All @@ -180,7 +228,6 @@ int dma_mmap_writecombine(struct device *, struct vm_area_struct *,
*/
extern void __init init_consistent_dma_size(unsigned long size);


/*
* For SA-1111, IXP425, and ADI systems the dma-mapping functions are "magic"
* and utilize bounce buffers as needed to work around limited DMA windows.
Expand Down
60 changes: 24 additions & 36 deletions arch/arm/mm/dma-mapping.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -113,6 +113,9 @@ static void arm_dma_sync_single_for_device(struct device *dev,
static int arm_dma_set_mask(struct device *dev, u64 dma_mask);

struct dma_map_ops arm_dma_ops = {
.alloc = arm_dma_alloc,
.free = arm_dma_free,
.mmap = arm_dma_mmap,
.map_page = arm_dma_map_page,
.unmap_page = arm_dma_unmap_page,
.map_sg = arm_dma_map_sg,
Expand Down Expand Up @@ -415,10 +418,19 @@ static void __dma_free_remap(void *cpu_addr, size_t size)
arm_vmregion_free(&consistent_head, c);
}

static inline pgprot_t __get_dma_pgprot(struct dma_attrs *attrs, pgprot_t prot)
{
prot = dma_get_attr(DMA_ATTR_WRITE_COMBINE, attrs) ?
pgprot_writecombine(prot) :
pgprot_dmacoherent(prot);
return prot;
}

#else /* !CONFIG_MMU */

#define __dma_alloc_remap(page, size, gfp, prot, c) page_address(page)
#define __dma_free_remap(addr, size) do { } while (0)
#define __get_dma_pgprot(attrs, prot) __pgprot(0)

#endif /* CONFIG_MMU */

Expand Down Expand Up @@ -462,41 +474,33 @@ __dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
* Allocate DMA-coherent memory space and return both the kernel remapped
* virtual and bus address for that space.
*/
void *
dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
void *arm_dma_alloc(struct device *dev, size_t size, dma_addr_t *handle,
gfp_t gfp, struct dma_attrs *attrs)
{
pgprot_t prot = __get_dma_pgprot(attrs, pgprot_kernel);
void *memory;

if (dma_alloc_from_coherent(dev, size, handle, &memory))
return memory;

return __dma_alloc(dev, size, handle, gfp,
pgprot_dmacoherent(pgprot_kernel),
return __dma_alloc(dev, size, handle, gfp, prot,
__builtin_return_address(0));
}
EXPORT_SYMBOL(dma_alloc_coherent);

/*
* Allocate a writecombining region, in much the same way as
* dma_alloc_coherent above.
* Create userspace mapping for the DMA-coherent memory.
*/
void *
dma_alloc_writecombine(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp)
{
return __dma_alloc(dev, size, handle, gfp,
pgprot_writecombine(pgprot_kernel),
__builtin_return_address(0));
}
EXPORT_SYMBOL(dma_alloc_writecombine);

static int dma_mmap(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
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)
{
int ret = -ENXIO;
#ifdef CONFIG_MMU
unsigned long user_size, kern_size;
struct arm_vmregion *c;

vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot);

if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
return ret;

Expand All @@ -521,27 +525,12 @@ static int dma_mmap(struct device *dev, struct vm_area_struct *vma,
return ret;
}

int dma_mmap_coherent(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
vma->vm_page_prot = pgprot_dmacoherent(vma->vm_page_prot);
return dma_mmap(dev, vma, cpu_addr, dma_addr, size);
}
EXPORT_SYMBOL(dma_mmap_coherent);

int dma_mmap_writecombine(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, dma_addr_t dma_addr, size_t size)
{
vma->vm_page_prot = pgprot_writecombine(vma->vm_page_prot);
return dma_mmap(dev, vma, cpu_addr, dma_addr, size);
}
EXPORT_SYMBOL(dma_mmap_writecombine);

/*
* free a page as defined by the above mapping.
* Must not be called with IRQs disabled.
*/
void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr_t handle)
void arm_dma_free(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t handle, struct dma_attrs *attrs)
{
WARN_ON(irqs_disabled());

Expand All @@ -555,7 +544,6 @@ void dma_free_coherent(struct device *dev, size_t size, void *cpu_addr, dma_addr

__dma_free_buffer(pfn_to_page(dma_to_pfn(dev, handle)), size);
}
EXPORT_SYMBOL(dma_free_coherent);

static void dma_cache_maint_page(struct page *page, unsigned long offset,
size_t size, enum dma_data_direction dir,
Expand Down

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