ARM: add dma coherent region reporting via procfs
Add a new seqfile for reporting coherent DMA allocations. This contains
the address range, size and the function which was used to allocate
each region, allowing these allocations to be viewed in much the same
way as /proc/vmallocinfo.
The DMA coherent region has limited space, so this allows allocation
failures to be viewed, as well as finding out how much space is being
used.
Make sure this file is only readable by root - same as vmallocinfo - to
prevent information leakage.
Acked-by: Nicolas Pitre <nico@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index 1aa664a..db23ae4 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -214,7 +214,8 @@
core_initcall(consistent_init);
static void *
-__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot)
+__dma_alloc_remap(struct page *page, size_t size, gfp_t gfp, pgprot_t prot,
+ const void *caller)
{
struct arm_vmregion *c;
size_t align;
@@ -241,7 +242,7 @@
* Allocate a virtual address in the consistent mapping region.
*/
c = arm_vmregion_alloc(&consistent_head, align, size,
- gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
+ gfp & ~(__GFP_DMA | __GFP_HIGHMEM), caller);
if (c) {
pte_t *pte;
int idx = CONSISTENT_PTE_INDEX(c->vm_start);
@@ -320,14 +321,14 @@
#else /* !CONFIG_MMU */
-#define __dma_alloc_remap(page, size, gfp, prot) page_address(page)
+#define __dma_alloc_remap(page, size, gfp, prot, c) page_address(page)
#define __dma_free_remap(addr, size) do { } while (0)
#endif /* CONFIG_MMU */
static void *
__dma_alloc(struct device *dev, size_t size, dma_addr_t *handle, gfp_t gfp,
- pgprot_t prot)
+ pgprot_t prot, const void *caller)
{
struct page *page;
void *addr;
@@ -349,7 +350,7 @@
return NULL;
if (!arch_is_coherent())
- addr = __dma_alloc_remap(page, size, gfp, prot);
+ addr = __dma_alloc_remap(page, size, gfp, prot, caller);
else
addr = page_address(page);
@@ -374,7 +375,8 @@
return memory;
return __dma_alloc(dev, size, handle, gfp,
- pgprot_dmacoherent(pgprot_kernel));
+ pgprot_dmacoherent(pgprot_kernel),
+ __builtin_return_address(0));
}
EXPORT_SYMBOL(dma_alloc_coherent);
@@ -386,7 +388,8 @@
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));
+ pgprot_writecombine(pgprot_kernel),
+ __builtin_return_address(0));
}
EXPORT_SYMBOL(dma_alloc_writecombine);
@@ -723,6 +726,9 @@
static int __init dma_debug_do_init(void)
{
+#ifdef CONFIG_MMU
+ arm_vmregion_create_proc("dma-mappings", &consistent_head);
+#endif
dma_debug_init(PREALLOC_DMA_DEBUG_ENTRIES);
return 0;
}