| Message ID | 1345630830-9586-3-git-send-email-hdoyu@nvidia.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
Hi. vzalloc() call in __iommu_alloc_buffer() also causes BUG() in atomic context. On Wed, Aug 22, 2012 at 7:20 PM, Hiroshi Doyu <hdoyu@nvidia.com> wrote: > 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@nvidia.com> > --- > 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@kvack.org. For more info on Linux MM, > see: http://www.linux-mm.org/ . > Don't email: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>
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);
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@nvidia.com> --- arch/arm/mm/dma-mapping.c | 22 ++++++++++++++++++---- 1 files changed, 18 insertions(+), 4 deletions(-)