[PATCH 16/28] x86: isolate coherent mapping functions

Glauber Costa
2008-04-08T16:20:58Z

i386 implements the declare coherent memory API, and x86_64 does not
it is reflected in pieces of dma_alloc_coherent and dma_free_coherent.
Those pieces are isolated in separate functions, that are declared
as empty macros in x86_64. This way we can make the code the same.

Signed-off-by: Glauber Costa <gcosta@redhat.com>
---
arch/x86/kernel/pci-dma_32.c | 51 ++++++++++++++++++++++++++++-------------
arch/x86/kernel/pci-dma_64.c | 11 ++++++++-
2 files changed, 45 insertions(+), 17 deletions(-)

diff --git a/arch/x86/kernel/pci-dma_32.c b/arch/x86/kernel/pci-dma_32.c
index 818d95e..78c7640 100644
--- a/arch/x86/kernel/pci-dma_32.c
+++ b/arch/x86/kernel/pci-dma_32.c
@@ -18,27 +18,50 @@
dma_addr_t bad_dma_address __read_mostly = 0x0;
EXPORT_SYMBOL(bad_dma_address);

-void *dma_alloc_coherent(struct device *dev, size_t size,
- dma_addr_t *dma_handle, gfp_t gfp)
+static int dma_alloc_from_coherent_mem(struct device *dev, ssize_t size,
+ dma_addr_t *dma_handle, void **ret)
{
- void *ret;
struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
int order = get_order(size);
- /* ignore region specifiers */
- gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);

if (mem) {
int page = bitmap_find_free_region(mem->bitmap, mem->size,
order);
if (page >= 0) {
*dma_handle = mem->device_base + (page << PAGE_SHIFT);
- ret = mem->virt_base + (page << PAGE_SHIFT);
- memset(ret, 0, size);
- return ret;
+ *ret = mem->virt_base + (page << PAGE_SHIFT);
+ memset(*ret, 0, size);
}
if (mem->flags & DMA_MEMORY_EXCLUSIVE)
- return NULL;
+ *ret = NULL;
+ }
+ return (mem != NULL);
+}
+
+static int dma_release_coherent(struct device *dev, int order, void *vaddr)
+{
+ struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
+
+ if (mem && vaddr >= mem->virt_base && vaddr <
+ (mem->virt_base + (mem->size << PAGE_SHIFT))) {
+ int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
+
+ bitmap_release_region(mem->bitmap, page, order);
+ return 1;
}
+ return 0;
+}
+
+void *dma_alloc_coherent(struct device *dev, size_t size,
+ dma_addr_t *dma_handle, gfp_t gfp)
+{
+ void *ret = NULL;
+ int order = get_order(size);
+ /* ignore region specifiers */
+ gfp &= ~(__GFP_DMA | __GFP_HIGHMEM);
+
+ if (dma_alloc_from_coherent_mem(dev, size, dma_handle, &ret))
+ return ret;

if (dev == NULL || (dev->coherent_dma_mask < 0xffffffff))
gfp |= GFP_DMA;
@@ -56,15 +79,11 @@ EXPORT_SYMBOL(dma_alloc_coherent);
void dma_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t dma_handle)
{
- struct dma_coherent_mem *mem = dev ? dev->dma_mem : NULL;
int order = get_order(size);

WARN_ON(irqs_disabled()); /* for portability */
- if (mem && vaddr >= mem->virt_base && vaddr < (mem->virt_base + (mem->size << PAGE_SHIFT))) {
- int page = (vaddr - mem->virt_base) >> PAGE_SHIFT;
-
- bitmap_release_region(mem->bitmap, page, order);
- } else
- free_pages((unsigned long)vaddr, order);
+ if (dma_release_coherent(dev, order, vaddr))
+ return;
+ free_pages((unsigned long)vaddr, order);
}
EXPORT_SYMBOL(dma_free_coherent);
diff --git a/arch/x86/kernel/pci-dma_64.c b/arch/x86/kernel/pci-dma_64.c
index e7d45cf..6eacd58 100644
--- a/arch/x86/kernel/pci-dma_64.c
+++ b/arch/x86/kernel/pci-dma_64.c
@@ -39,6 +39,8 @@ dma_alloc_pages(struct device *dev, gfp_t gfp, unsigned order)
return page ? page_address(page) : NULL;
}

+#define dma_alloc_from_coherent_mem(dev, size, handle, ret) (0)
+#define dma_release_coherent(dev, order, vaddr) (0)
/*
* Allocate memory for a coherent mapping.
*/
@@ -50,6 +52,10 @@ dma_alloc_coherent(struct device *dev, size_t size, dma_addr_t *dma_handle,
unsigned long dma_mask = 0;
u64 bus;

+
+ if (dma_alloc_from_coherent_mem(dev, size, dma_handle, &memory))
+ return memory;
+
if (!dev)
dev = &fallback_dev;
dma_mask = dev->coherent_dma_mask;
@@ -141,9 +147,12 @@ EXPORT_SYMBOL(dma_alloc_coherent);
void dma_free_coherent(struct device *dev, size_t size,
void *vaddr, dma_addr_t bus)
{
+ int order = get_order(size);
WARN_ON(irqs_disabled()); /* for portability */
+ if (dma_release_coherent(dev, order, vaddr))
+ return;
if (dma_ops->unmap_single)
dma_ops->unmap_single(dev, bus, size, 0);
- free_pages((unsigned long)vaddr, get_order(size));
+ free_pages((unsigned long)vaddr, order);
}
EXPORT_SYMBOL(dma_free_coherent);
--
1.5.0.6