From 90ae409f9eb3bcaf38688f9ec22375816053a08e Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
Date: Tue, 20 Aug 2019 11:45:49 +0900
Subject: dma-direct: fix zone selection after an unaddressable CMA allocation
The new dma_alloc_contiguous hides if we allocate CMA or regular
pages, and thus fails to retry a ZONE_NORMAL allocation if the CMA
allocation succeeds but isn't addressable. That means we either fail
outright or dip into a small zone that might not succeed either.
Thanks to Hillf Danton for debugging this issue.
Fixes: b1d2dc009dec ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Reported-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Tested-by: Tobias Klausmann <tobias.johannes.klausmann@mni.thm.de>
---
kernel/dma/contiguous.c | 8 ++------
kernel/dma/direct.c | 10 +++++++++-
2 files changed, 11 insertions(+), 7 deletions(-)
(limited to 'kernel/dma')
diff --git a/kernel/dma/contiguous.c b/kernel/dma/contiguous.c
index 2bd410f934b3..69cfb4345388 100644
--- a/kernel/dma/contiguous.c
+++ b/kernel/dma/contiguous.c
@@ -230,9 +230,7 @@ bool dma_release_from_contiguous(struct device *dev, struct page *pages,
*/
struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp)
{
- int node = dev ? dev_to_node(dev) : NUMA_NO_NODE;
- size_t count = PAGE_ALIGN(size) >> PAGE_SHIFT;
- size_t align = get_order(PAGE_ALIGN(size));
+ size_t count = size >> PAGE_SHIFT;
struct page *page = NULL;
struct cma *cma = NULL;
@@ -243,14 +241,12 @@ struct page *dma_alloc_contiguous(struct device *dev, size_t size, gfp_t gfp)
/* CMA can be used only in the context which permits sleeping */
if (cma && gfpflags_allow_blocking(gfp)) {
+ size_t align = get_order(size);
size_t cma_align = min_t(size_t, align, CONFIG_CMA_ALIGNMENT);
page = cma_alloc(cma, count, cma_align, gfp & __GFP_NOWARN);
}
- /* Fallback allocation of normal pages */
- if (!page)
- page = alloc_pages_node(node, gfp, align);
return page;
}
diff --git a/kernel/dma/direct.c b/kernel/dma/direct.c
index 795c9b095d75..706113c6bebc 100644
--- a/kernel/dma/direct.c
+++ b/kernel/dma/direct.c
@@ -85,6 +85,8 @@ static bool dma_coherent_ok(struct device *dev, phys_addr_t phys, size_t size)
struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
dma_addr_t *dma_handle, gfp_t gfp, unsigned long attrs)
{
+ size_t alloc_size = PAGE_ALIGN(size);
+ int node = dev_to_node(dev);
struct page *page = NULL;
u64 phys_mask;
@@ -95,8 +97,14 @@ struct page *__dma_direct_alloc_pages(struct device *dev, size_t size,
gfp &= ~__GFP_ZERO;
gfp |= __dma_direct_optimal_gfp_mask(dev, dev->coherent_dma_mask,
&phys_mask);
+ page = dma_alloc_contiguous(dev, alloc_size, gfp);
+ if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
+ dma_free_contiguous(dev, page, alloc_size);
+ page = NULL;
+ }
again:
- page = dma_alloc_contiguous(dev, size, gfp);
+ if (!page)
+ page = alloc_pages_node(node, gfp, get_order(alloc_size));
if (page && !dma_coherent_ok(dev, page_to_phys(page), size)) {
dma_free_contiguous(dev, page, size);
page = NULL;
--
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