The attempt to handle huge page allocations was originally added since
the comments around stripping __GFP_COMP in other implementations were
nonsensical, and we naively assumed that split_huge_page() could simply
be called equivalently to split_page(). It turns out that this doesn't
actually work correctly, so just get rid of it - there's little point
going to the effort of allocating huge pages if we're only going to
split them anyway.
Reported-by: Roman Gushchin <guro@xxxxxx>
Signed-off-by: Robin Murphy <robin.murphy@xxxxxxx>
---
drivers/iommu/dma-iommu.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)
diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c
index 4959f5df21bd..9194088b088f 100644
--- a/drivers/iommu/dma-iommu.c
+++ b/drivers/iommu/dma-iommu.c
@@ -524,6 +524,9 @@ static struct page **__iommu_dma_alloc_pages(struct device *dev,
/* IOMMU can map any pages, so himem can also be used here */
gfp |= __GFP_NOWARN | __GFP_HIGHMEM;
+ /* It makes no sense to muck about with huge pages */
+ gfp &= ~__GFP_COMP;
+
while (count) {
struct page *page = NULL;
unsigned int order_size;
@@ -544,15 +547,9 @@ static struct page **__iommu_dma_alloc_pages(struct device *dev,
page = alloc_pages_node(nid, alloc_flags, order);
if (!page)
continue;
- if (!order)
- break;
- if (!PageCompound(page)) {
+ if (order)
split_page(page, order);
- break;
- } else if (!split_huge_page(page)) {
- break;
- }
- __free_pages(page, order);
+ break;
}
if (!page) {
__iommu_dma_free_pages(pages, i);
--
2.28.0.dirty
