Makes use of the same atomic pool from DMA, and skips kernel page
mapping which can involves sleep'able operation at allocating a kernel
page table.
Signed-off-by: Hiroshi Doyu <hdoyu@xxxxxxxxxx>
---
arch/arm/mm/dma-mapping.c | 22 ++++++++++++++++++----
1 files changed, 18 insertions(+), 4 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c
index aec0c06..9260107 100644
--- a/arch/arm/mm/dma-mapping.c
+++ b/arch/arm/mm/dma-mapping.c
@@ -1028,7 +1028,6 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size,
struct page **pages;
int count = size >> PAGE_SHIFT;
int array_size = count * sizeof(struct page *);
- int err;
if (array_size <= PAGE_SIZE)
pages = kzalloc(array_size, gfp);
@@ -1037,9 +1036,20 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size,
if (!pages)
return NULL;
- err = __alloc_fill_pages(&pages, count, gfp);
- if (err)
- goto error
+ if (gfp & GFP_ATOMIC) {
+ struct page *page;
+ int i;
+ void *addr = __alloc_from_pool(size, &page);
+ if (!addr)
+ goto err_out;
+
+ for (i = 0; i < count; i++)
+ pages[i] = page + i;
+ } else {
+ int err = __alloc_fill_pages(&pages, count, gfp);
+ if (err)
+ goto error;
+ }
return pages;
error:
@@ -1055,6 +1065,10 @@ static int __iommu_free_buffer(struct device *dev, struct page **pages, size_t s
int count = size >> PAGE_SHIFT;
int array_size = count * sizeof(struct page *);
int i;
+
+ if (__free_from_pool(page_address(pages[0]), size))
+ return 0;
+
for (i = 0; i < count; i++)
if (pages[i])
__free_pages(pages[i], 0);
--
1.7.5.4
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>