[PATCH RFC/RFT 4/5] arm64: dma-mapping: Add fallback normal page allocations

Nicolin Chen
2019-03-26T22:50:19Z

from normal area. So this patch adds fallback routines.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
---
arch/arm64/mm/dma-mapping.c | 19 ++++++++++++-------
1 file changed, 12 insertions(+), 7 deletions(-)

diff --git a/arch/arm64/mm/dma-mapping.c b/arch/arm64/mm/dma-mapping.c
index 78c0a72f822c..be2302533334 100644
--- a/arch/arm64/mm/dma-mapping.c
+++ b/arch/arm64/mm/dma-mapping.c
@@ -156,17 +156,20 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size,
}
} else if (attrs & DMA_ATTR_FORCE_CONTIGUOUS) {
pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
+ unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
struct page *page;

- page = dma_alloc_from_contiguous(dev, size >> PAGE_SHIFT,
- get_order(size), gfp & __GFP_NOWARN);
+ page = dma_alloc_from_contiguous(dev, count, get_order(size),
+ gfp & __GFP_NOWARN);
+ if (!page)
+ page = alloc_pages(gfp, get_order(size));
if (!page)
return NULL;

*handle = iommu_dma_map_page(dev, page, 0, iosize, ioprot);
if (*handle == DMA_MAPPING_ERROR) {
- dma_release_from_contiguous(dev, page,
- size >> PAGE_SHIFT);
+ if (!dma_release_from_contiguous(dev, page, count))
+ __free_pages(page, get_order(size));
return NULL;
}
addr = dma_common_contiguous_remap(page, size, VM_USERMAP,
@@ -178,8 +181,8 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size,
memset(addr, 0, size);
} else {
iommu_dma_unmap_page(dev, *handle, iosize, 0, attrs);
- dma_release_from_contiguous(dev, page,
- size >> PAGE_SHIFT);
+ if (!dma_release_from_contiguous(dev, page, count))
+ __free_pages(page, get_order(size));
}
} else {
pgprot_t prot = arch_dma_mmap_pgprot(dev, PAGE_KERNEL, attrs);
@@ -201,6 +204,7 @@ static void *__iommu_alloc_attrs(struct device *dev, size_t size,
static void __iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
dma_addr_t handle, unsigned long attrs)
{
+ unsigned long count = PAGE_ALIGN(size) >> PAGE_SHIFT;
size_t iosize = size;

size = PAGE_ALIGN(size);
@@ -222,7 +226,8 @@ static void __iommu_free_attrs(struct device *dev, size_t size, void *cpu_addr,
struct page *page = vmalloc_to_page(cpu_addr);

iommu_dma_unmap_page(dev, handle, iosize, 0, attrs);
- dma_release_from_contiguous(dev, page, size >> PAGE_SHIFT);
+ if (!dma_release_from_contiguous(dev, page, count))
+ __free_pages(page, get_order(size));
dma_common_free_remap(cpu_addr, size, VM_USERMAP);
} else if (is_vmalloc_addr(cpu_addr)){
struct vm_struct *area = find_vm_area(cpu_addr);
--
2.17.1