__alloc_fill_pages() allocates power of 2 page number allocation at most repeatedly.
Signed-off-by: Hiroshi Doyu hdoyu@nvidia.com --- arch/arm/mm/dma-mapping.c | 50 ++++++++++++++++++++++++++++++-------------- 1 files changed, 34 insertions(+), 16 deletions(-)
diff --git a/arch/arm/mm/dma-mapping.c b/arch/arm/mm/dma-mapping.c index b64475a..7ab016b 100644 --- a/arch/arm/mm/dma-mapping.c +++ b/arch/arm/mm/dma-mapping.c @@ -1022,20 +1022,11 @@ static inline void __free_iova(struct dma_iommu_mapping *mapping, spin_unlock_irqrestore(&mapping->lock, flags); }
-static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, gfp_t gfp) +static int __alloc_fill_pages(struct page ***ppages, int count, gfp_t gfp) { - struct page **pages; - int count = size >> PAGE_SHIFT; - int array_size = count * sizeof(struct page *); + struct page **pages = *ppages; int i = 0;
- if ((array_size <= PAGE_SIZE) || (gfp & GFP_ATOMIC)) - pages = kzalloc(array_size, gfp); - else - pages = vzalloc(array_size); - if (!pages) - return NULL; - while (count) { int j, order = __fls(count);
@@ -1045,22 +1036,49 @@ static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, gfp_t if (!pages[i]) goto error;
- if (order) + if (order) { split_page(pages[i], order); - j = 1 << order; - while (--j) - pages[i + j] = pages[i] + j; + j = 1 << order; + while (--j) + pages[i + j] = pages[i] + j; + }
__dma_clear_buffer(pages[i], PAGE_SIZE << order); i += 1 << order; count -= 1 << order; }
- return pages; + return 0; + error: while (i--) if (pages[i]) __free_pages(pages[i], 0); + return -ENOMEM; +} + +static struct page **__iommu_alloc_buffer(struct device *dev, size_t size, + gfp_t gfp) +{ + struct page **pages; + int count = size >> PAGE_SHIFT; + int array_size = count * sizeof(struct page *); + int err; + + if ((array_size <= PAGE_SIZE) || (gfp & GFP_ATOMIC)) + pages = kzalloc(array_size, gfp); + else + pages = vzalloc(array_size); + if (!pages) + return NULL; + + err = __alloc_fill_pages(&pages, count, gfp); + if (err) + goto error + + return pages; + +error: if ((array_size <= PAGE_SIZE) || (gfp & GFP_ATOMIC)) kfree(pages); else