The patch titled
Subject: dma-contiguous: fix !CONFIG_DMA_CMA version of dma_{alloc,free}_contiguous()
has been added to the -mm tree. Its filename is
dma-contiguous-fix-config_dma_cma-version-of-dma_allocfree_contiguous.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/dma-contiguous-fix-config_dma_cma-version-of-dma_allocfree_contiguous.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/dma-contiguous-fix-config_dma_cma-version-of-dma_allocfree_contiguous.patch
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------------------------------------------------------
From: Nicolin Chen <nicoleotsuka@xxxxxxxxx>
Subject: dma-contiguous: fix !CONFIG_DMA_CMA version of dma_{alloc,free}_contiguous()
fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
adds a pair of new helper functions so as to abstract code in the
dma-direct (and other places in the future), however it breaks QEMU boot
feature using x86_64 defconfig.
That's because x86_64 defconfig has CONFIG_DMA_CMA=n so those two newly
introduced helper functions are empty in their !CONFIG_DMA_CMA version,
while previously the platform independent dma-direct code had fallback
alloc_pages_node() and __free_pages().
So this patch fixes it by adding alloc_pages_node() and __free_pages() in
the !CONFIG_DMA_CMA version of the two helper functions.
Tested with below QEMU command:
qemu-system-x86_64 -m 512m \
-drive file=images/x86_64/rootfs.ext4,format=raw,if=ide \
-append 'console=ttyS0 root=/dev/sda' -nographic \
-kernel arch/x86_64/boot/bzImage
with the rootfs from the below link:
https://github.com/ClangBuiltLinux/continuous-integration/raw/master/images/x86_64/rootfs.ext4
Link: http://lkml.kernel.org/r/20190530005425.7184-1-nicoleotsuka@xxxxxxxxx
Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers")
Signed-off-by: Nicolin Chen <nicoleotsuka@xxxxxxxxx>
Reported-by: Nathan Chancellor <natechancellor@xxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/dma-contiguous.h | 8 +++++++-
1 file changed, 7 insertions(+), 1 deletion(-)
--- a/include/linux/dma-contiguous.h~dma-contiguous-fix-config_dma_cma-version-of-dma_allocfree_contiguous
+++ a/include/linux/dma-contiguous.h
@@ -50,6 +50,7 @@
#ifdef __KERNEL__
#include <linux/device.h>
+#include <linux/mm.h>
struct cma;
struct page;
@@ -155,15 +156,20 @@ bool dma_release_from_contiguous(struct
return false;
}
+/* Use fallback alloc() and free() when CONFIG_DMA_CMA=n */
static inline struct page *dma_alloc_contiguous(struct device *dev, size_t size,
gfp_t gfp)
{
- return NULL;
+ int node = dev ? dev_to_node(dev) : NUMA_NO_NODE;
+ size_t align = get_order(PAGE_ALIGN(size));
+
+ return alloc_pages_node(node, gfp, align);
}
static inline void dma_free_contiguous(struct device *dev, struct page *page,
size_t size)
{
+ __free_pages(page, get_order(size));
}
#endif
_
Patches currently in -mm which might be from nicoleotsuka@xxxxxxxxx are
dma-contiguous-fix-config_dma_cma-version-of-dma_allocfree_contiguous.patch
