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dma-coherent: introduce interface for default DMA pool 

Christoph noticed [1] that default DMA pool in current form overload
the DMA coherent infrastructure. In reply, Robin suggested [2] to
split the per-device vs. global pool interfaces, so allocation/release
from default DMA pool is driven by dma ops implementation.

This patch implements Robin's idea and provide interface to
allocate/release/mmap the default (aka global) DMA pool.

To make it clear that existing *_from_coherent routines work on
per-device pool rename them to *_from_dev_coherent.

[1] https://lkml.org/lkml/2017/7/7/370
[2] https://lkml.org/lkml/2017/7/7/431

Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Ralf Baechle <ralf@linux-mips.org>
Suggested-by: Robin Murphy <robin.murphy@arm.com>
Tested-by: Andras Szemzo <sza@esh.hu>
Reviewed-by: Robin Murphy <robin.murphy@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Vladimir Murzin 2017-07-20 11:19:58 +01:00 committed by Christoph Hellwig
parent 5771a8c088
commit 43fc509c3e
7 changed files with 149 additions and 77 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
arch/arc/mm/dma.c
View File

@ -117,7 +117,7 @@ static int arc_dma_mmap(struct device *dev, struct vm_area_struct *vma,
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
if (off < count && user_count <= (count - off)) {

2
arch/arm/mm/dma-mapping.c
View File

@ -851,7 +851,7 @@ static int __arm_dma_mmap(struct device *dev, struct vm_area_struct *vma,
unsigned long pfn = dma_to_pfn(dev, dma_addr);
unsigned long off = vma->vm_pgoff;
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
if (off < nr_pages && nr_vma_pages <= (nr_pages - off)) {

4
arch/arm64/mm/dma-mapping.c
View File

@ -329,7 +329,7 @@ static int __swiotlb_mmap(struct device *dev,
vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
is_device_dma_coherent(dev));
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
return __swiotlb_mmap_pfn(vma, pfn, size);
@ -706,7 +706,7 @@ static int __iommu_mmap_attrs(struct device *dev, struct vm_area_struct *vma,
vma->vm_page_prot = __get_dma_pgprot(attrs, vma->vm_page_prot,
is_device_dma_coherent(dev));
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {

2
arch/mips/mm/dma-default.c
View File

@ -232,7 +232,7 @@ static int mips_dma_mmap(struct device *dev, struct vm_area_struct *vma,
else
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
if (off < count && user_count <= (count - off)) {

174
drivers/base/dma-coherent.c
View File

@ -25,7 +25,7 @@ static inline struct dma_coherent_mem *dev_get_coherent_memory(struct device *de
{
if (dev && dev->dma_mem)
return dev->dma_mem;
return dma_coherent_default_memory;
return NULL;
}
static inline dma_addr_t dma_get_device_base(struct device *dev,
@ -165,9 +165,45 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
}
EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
static void *__dma_alloc_from_coherent(struct dma_coherent_mem *mem,
ssize_t size, dma_addr_t *dma_handle)
{
int order = get_order(size);
unsigned long flags;
int pageno;
int dma_memory_map;
void *ret;
spin_lock_irqsave(&mem->spinlock, flags);
if (unlikely(size > (mem->size << PAGE_SHIFT)))
goto err;
pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
if (unlikely(pageno < 0))
goto err;
/*
* Memory was found in the coherent area.
*/
*dma_handle = mem->device_base + (pageno << PAGE_SHIFT);
ret = mem->virt_base + (pageno << PAGE_SHIFT);
dma_memory_map = (mem->flags & DMA_MEMORY_MAP);
spin_unlock_irqrestore(&mem->spinlock, flags);
if (dma_memory_map)
memset(ret, 0, size);
else
memset_io(ret, 0, size);
return ret;
err:
spin_unlock_irqrestore(&mem->spinlock, flags);
return NULL;
}
/**
* dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area
*
* dma_alloc_from_dev_coherent() - allocate memory from device coherent pool
* @dev: device from which we allocate memory
* @size: size of requested memory area
* @dma_handle: This will be filled with the correct dma handle
@ -180,44 +216,18 @@ EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
* Returns 0 if dma_alloc_coherent should continue with allocating from
* generic memory areas, or !0 if dma_alloc_coherent should return @ret.
*/
int dma_alloc_from_coherent(struct device *dev, ssize_t size,
dma_addr_t *dma_handle, void **ret)
int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,
dma_addr_t *dma_handle, void **ret)
{
struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
int order = get_order(size);
unsigned long flags;
int pageno;
int dma_memory_map;
if (!mem)
return 0;
*ret = NULL;
spin_lock_irqsave(&mem->spinlock, flags);
*ret = __dma_alloc_from_coherent(mem, size, dma_handle);
if (*ret)
return 1;
if (unlikely(size > (mem->size << PAGE_SHIFT)))
goto err;
pageno = bitmap_find_free_region(mem->bitmap, mem->size, order);
if (unlikely(pageno < 0))
goto err;
/*
* Memory was found in the per-device area.
*/
*dma_handle = dma_get_device_base(dev, mem) + (pageno << PAGE_SHIFT);
*ret = mem->virt_base + (pageno << PAGE_SHIFT);
dma_memory_map = (mem->flags & DMA_MEMORY_MAP);
spin_unlock_irqrestore(&mem->spinlock, flags);
if (dma_memory_map)
memset(*ret, 0, size);
else
memset_io(*ret, 0, size);
return 1;
err:
spin_unlock_irqrestore(&mem->spinlock, flags);
/*
* In the case where the allocation can not be satisfied from the
* per-device area, try to fall back to generic memory if the
@ -225,25 +235,20 @@ err:
*/
return mem->flags & DMA_MEMORY_EXCLUSIVE;
}
EXPORT_SYMBOL(dma_alloc_from_coherent);
EXPORT_SYMBOL(dma_alloc_from_dev_coherent);
/**
* dma_release_from_coherent() - try to free the memory allocated from per-device coherent memory pool
* @dev: device from which the memory was allocated
* @order: the order of pages allocated
* @vaddr: virtual address of allocated pages
*
* This checks whether the memory was allocated from the per-device
* coherent memory pool and if so, releases that memory.
*
* Returns 1 if we correctly released the memory, or 0 if
* dma_release_coherent() should proceed with releasing memory from
* generic pools.
*/
int dma_release_from_coherent(struct device *dev, int order, void *vaddr)
void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle)
{
struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
if (!dma_coherent_default_memory)
return NULL;
return __dma_alloc_from_coherent(dma_coherent_default_memory, size,
dma_handle);
}
static int __dma_release_from_coherent(struct dma_coherent_mem *mem,
int order, void *vaddr)
{
if (mem && vaddr >= mem->virt_base && vaddr <
(mem->virt_base + (mem->size << PAGE_SHIFT))) {
int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
@ -256,28 +261,39 @@ int dma_release_from_coherent(struct device *dev, int order, void *vaddr)
}
return 0;
}
EXPORT_SYMBOL(dma_release_from_coherent);
/**
* dma_mmap_from_coherent() - try to mmap the memory allocated from
* per-device coherent memory pool to userspace
* dma_release_from_dev_coherent() - free memory to device coherent memory pool
* @dev: device from which the memory was allocated
* @vma: vm_area for the userspace memory
* @vaddr: cpu address returned by dma_alloc_from_coherent
* @size: size of the memory buffer allocated by dma_alloc_from_coherent
* @ret: result from remap_pfn_range()
* @order: the order of pages allocated
* @vaddr: virtual address of allocated pages
*
* This checks whether the memory was allocated from the per-device
* coherent memory pool and if so, maps that memory to the provided vma.
* coherent memory pool and if so, releases that memory.
*
* Returns 1 if we correctly mapped the memory, or 0 if the caller should
* proceed with mapping memory from generic pools.
* Returns 1 if we correctly released the memory, or 0 if the caller should
* proceed with releasing memory from generic pools.
*/
int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma,
void *vaddr, size_t size, int *ret)
int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr)
{
struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
return __dma_release_from_coherent(mem, order, vaddr);
}
EXPORT_SYMBOL(dma_release_from_dev_coherent);
int dma_release_from_global_coherent(int order, void *vaddr)
{
if (!dma_coherent_default_memory)
return 0;
return __dma_release_from_coherent(dma_coherent_default_memory, order,
vaddr);
}
static int __dma_mmap_from_coherent(struct dma_coherent_mem *mem,
struct vm_area_struct *vma, void *vaddr, size_t size, int *ret)
{
if (mem && vaddr >= mem->virt_base && vaddr + size <=
(mem->virt_base + (mem->size << PAGE_SHIFT))) {
unsigned long off = vma->vm_pgoff;
@ -296,7 +312,39 @@ int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma,
}
return 0;
}
EXPORT_SYMBOL(dma_mmap_from_coherent);
/**
* dma_mmap_from_dev_coherent() - mmap memory from the device coherent pool
* @dev: device from which the memory was allocated
* @vma: vm_area for the userspace memory
* @vaddr: cpu address returned by dma_alloc_from_dev_coherent
* @size: size of the memory buffer allocated
* @ret: result from remap_pfn_range()
*
* This checks whether the memory was allocated from the per-device
* coherent memory pool and if so, maps that memory to the provided vma.
*
* Returns 1 if we correctly mapped the memory, or 0 if the caller should
* proceed with mapping memory from generic pools.
*/
int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma,
void *vaddr, size_t size, int *ret)
{
struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
return __dma_mmap_from_coherent(mem, vma, vaddr, size, ret);
}
EXPORT_SYMBOL(dma_mmap_from_dev_coherent);
int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *vaddr,
size_t size, int *ret)
{
if (!dma_coherent_default_memory)
return 0;
return __dma_mmap_from_coherent(dma_coherent_default_memory, vma,
vaddr, size, ret);
}
/*
* Support for reserved memory regions defined in device tree

2
drivers/base/dma-mapping.c
View File

@ -235,7 +235,7 @@ int dma_common_mmap(struct device *dev, struct vm_area_struct *vma,
vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
if (dma_mmap_from_coherent(dev, vma, cpu_addr, size, &ret))
if (dma_mmap_from_dev_coherent(dev, vma, cpu_addr, size, &ret))
return ret;
if (off < count && user_count <= (count - off)) {

40
include/linux/dma-mapping.h
View File

@ -157,16 +157,40 @@ static inline int is_device_dma_capable(struct device *dev)
* These three functions are only for dma allocator.
* Don't use them in device drivers.
*/
int dma_alloc_from_coherent(struct device *dev, ssize_t size,
int dma_alloc_from_dev_coherent(struct device *dev, ssize_t size,
dma_addr_t *dma_handle, void **ret);
int dma_release_from_coherent(struct device *dev, int order, void *vaddr);
int dma_release_from_dev_coherent(struct device *dev, int order, void *vaddr);
int dma_mmap_from_coherent(struct device *dev, struct vm_area_struct *vma,
int dma_mmap_from_dev_coherent(struct device *dev, struct vm_area_struct *vma,
void *cpu_addr, size_t size, int *ret);
void *dma_alloc_from_global_coherent(ssize_t size, dma_addr_t *dma_handle);
int dma_release_from_global_coherent(int order, void *vaddr);
int dma_mmap_from_global_coherent(struct vm_area_struct *vma, void *cpu_addr,
size_t size, int *ret);
#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)
#define dma_alloc_from_dev_coherent(dev, size, handle, ret) (0)
#define dma_release_from_dev_coherent(dev, order, vaddr) (0)
#define dma_mmap_from_dev_coherent(dev, vma, vaddr, order, ret) (0)
static inline void *dma_alloc_from_global_coherent(ssize_t size,
dma_addr_t *dma_handle)
{
return NULL;
}
static inline int dma_release_from_global_coherent(int order, void *vaddr)
{
return 0;
}
static inline int dma_mmap_from_global_coherent(struct vm_area_struct *vma,
void *cpu_addr, size_t size,
int *ret)
{
return 0;
}
#endif /* CONFIG_HAVE_GENERIC_DMA_COHERENT */
#ifdef CONFIG_HAS_DMA
@ -481,7 +505,7 @@ static inline void *dma_alloc_attrs(struct device *dev, size_t size,
BUG_ON(!ops);
if (dma_alloc_from_coherent(dev, size, dma_handle, &cpu_addr))
if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr))
return cpu_addr;
if (!arch_dma_alloc_attrs(&dev, &flag))
@ -503,7 +527,7 @@ static inline void dma_free_attrs(struct device *dev, size_t size,
BUG_ON(!ops);
WARN_ON(irqs_disabled());
if (dma_release_from_coherent(dev, get_order(size), cpu_addr))
if (dma_release_from_dev_coherent(dev, get_order(size), cpu_addr))
return;
if (!ops->free || !cpu_addr)