diff options
Diffstat (limited to 'kernel/dma/mapping.c')
| -rw-r--r-- | kernel/dma/mapping.c | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/kernel/dma/mapping.c b/kernel/dma/mapping.c index 33437d620644..68106e3791f6 100644 --- a/kernel/dma/mapping.c +++ b/kernel/dma/mapping.c @@ -498,6 +498,14 @@ void *dma_alloc_attrs(struct device *dev, size_t size, dma_addr_t *dma_handle, WARN_ON_ONCE(!dev->coherent_dma_mask); + /* + * DMA allocations can never be turned back into a page pointer, so + * requesting compound pages doesn't make sense (and can't even be + * supported at all by various backends). + */ + if (WARN_ON_ONCE(flag & __GFP_COMP)) + return NULL; + if (dma_alloc_from_dev_coherent(dev, size, dma_handle, &cpu_addr)) return cpu_addr; @@ -552,6 +560,8 @@ static struct page *__dma_alloc_pages(struct device *dev, size_t size, return NULL; if (WARN_ON_ONCE(gfp & (__GFP_DMA | __GFP_DMA32 | __GFP_HIGHMEM))) return NULL; + if (WARN_ON_ONCE(gfp & __GFP_COMP)) + return NULL; size = PAGE_ALIGN(size); if (dma_alloc_direct(dev, ops)) @@ -637,6 +647,8 @@ struct sg_table *dma_alloc_noncontiguous(struct device *dev, size_t size, if (WARN_ON_ONCE(attrs & ~DMA_ATTR_ALLOC_SINGLE_PAGES)) return NULL; + if (WARN_ON_ONCE(gfp & __GFP_COMP)) + return NULL; if (ops && ops->alloc_noncontiguous) sgt = ops->alloc_noncontiguous(dev, size, dir, gfp, attrs); |