[PATCH 1/2] drivers: dma-coherent: Introduce interface for default DMA pool
From: Vladimir Murzin
Date: Thu Jul 20 2017 - 06:21:19 EST
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@xxxxxxxxxxxx>
Cc: Russell King <linux@xxxxxxxxxxxxxxx>
Cc: Catalin Marinas <catalin.marinas@xxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Suggested-by: Robin Murphy <robin.murphy@xxxxxxx>
Tested-by: Andras Szemzo <sza@xxxxxx>
Signed-off-by: Vladimir Murzin <vladimir.murzin@xxxxxxx>
---
arch/arc/mm/dma.c | 2 +-
arch/arm/mm/dma-mapping.c | 2 +-
arch/arm64/mm/dma-mapping.c | 4 +-
arch/mips/mm/dma-default.c | 2 +-
drivers/base/dma-coherent.c | 169 +++++++++++++++++++++++++++++---------------
drivers/base/dma-mapping.c | 2 +-
include/linux/dma-mapping.h | 40 ++++++++---
7 files changed, 149 insertions(+), 72 deletions(-)
diff --git a/arch/arc/mm/dma.c b/arch/arc/mm/dma.c
index 2a07e6e..71d3eff 100644
--- a/arch/arc/mm/dma.c
+++ b/arch/arc/mm/dma.c
@@ -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)) {
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index e7380ba..fcf1473 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -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)) {
diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index e90cd1d..f27d4dd 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -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) {
diff --git a/arch/mips/mm/dma-default.c b/arch/mips/mm/dma-default.c
index e08598c..8e78251 100644
--- a/arch/mips/mm/dma-default.c
+++ b/arch/mips/mm/dma-default.c
@@ -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)) {
diff --git a/drivers/base/dma-coherent.c b/drivers/base/dma-coherent.c
index 2ae24c2..d6f231c 100644
--- a/drivers/base/dma-coherent.c
+++ b/drivers/base/dma-coherent.c
@@ -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,
@@ -165,34 +165,15 @@ void *dma_mark_declared_memory_occupied(struct device *dev,
}
EXPORT_SYMBOL(dma_mark_declared_memory_occupied);
-/**
- * dma_alloc_from_coherent() - try to allocate memory from the per-device coherent area
- *
- * @dev: device from which we allocate memory
- * @size: size of requested memory area
- * @dma_handle: This will be filled with the correct dma handle
- * @ret: This pointer will be filled with the virtual address
- * to allocated area.
- *
- * This function should be only called from per-arch dma_alloc_coherent()
- * to support allocation from per-device coherent memory pools.
- *
- * 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)
+static void *__dma_alloc_from_dev_coherent(struct dma_coherent_mem *mem,
+ ssize_t size, dma_addr_t *dma_handle)
{
- struct dma_coherent_mem *mem = dev_get_coherent_memory(dev);
int order = get_order(size);
unsigned long flags;
int pageno;
int dma_memory_map;
+ void *ret;
- if (!mem)
- return 0;
-
- *ret = NULL;
spin_lock_irqsave(&mem->spinlock, flags);
if (unlikely(size > (mem->size << PAGE_SHIFT)))
@@ -203,21 +184,51 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size,
goto err;
/*
- * Memory was found in the per-device area.
+ * Memory was found in the coherent area.
*/
- *dma_handle = dma_get_device_base(dev, mem) + (pageno << PAGE_SHIFT);
- *ret = mem->virt_base + (pageno << PAGE_SHIFT);
+ *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);
+ memset(ret, 0, size);
else
- memset_io(*ret, 0, size);
+ memset_io(ret, 0, size);
- return 1;
+ return ret;
err:
spin_unlock_irqrestore(&mem->spinlock, flags);
+ return NULL;
+}
+
+/**
+ * dma_alloc_from_dev_coherent() - try to allocate memory from the per-device coherent area
+ *
+ * @dev: device from which we allocate memory
+ * @size: size of requested memory area
+ * @dma_handle: This will be filled with the correct dma handle
+ * @ret: This pointer will be filled with the virtual address
+ * to allocated area.
+ *
+ * This function should be only called from per-arch dma_alloc_coherent()
+ * to support allocation from per-device coherent memory pools.
+ *
+ * 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_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);
+
+ if (!mem)
+ return 0;
+
+ *ret = __dma_alloc_from_dev_coherent(mem, size, dma_handle);
+ if (*ret)
+ return 1;
+
/*
* 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 +236,20 @@ int dma_alloc_from_coherent(struct device *dev, ssize_t size,
*/
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_dev_coherent(dma_coherent_default_memory, size, dma_handle);
+}
+
+
+static int __dma_release_from_dev_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 +262,42 @@ 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() - try to free the memory allocated from per-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
+ * dma_release_coherent() 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_dev_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_dev_coherent(dma_coherent_default_memory,
+ order, vaddr);
+}
+
+static int __dma_mmap_from_dev_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 +316,40 @@ 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() - try to mmap the memory allocated from
+ * per-device coherent memory pool to userspace
+ * @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 by dma_alloc_from_dev_coherent
+ * @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_dev_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_dev_coherent(dma_coherent_default_memory, vma,
+ vaddr, size, ret);
+}
/*
* Support for reserved memory regions defined in device tree
diff --git a/drivers/base/dma-mapping.c b/drivers/base/dma-mapping.c
index 5096755..b555ff9 100644
--- a/drivers/base/dma-mapping.c
+++ b/drivers/base/dma-mapping.c
@@ -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)) {
diff --git a/include/linux/dma-mapping.h b/include/linux/dma-mapping.h
index 843ab86..03c0196 100644
--- a/include/linux/dma-mapping.h
+++ b/include/linux/dma-mapping.h
@@ -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)
--
2.0.0