Commit 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 Fixes: fdaeec198ada ("dma-contiguous: add dma_{alloc,free}_contiguous() helpers") Reported-by: Nathan Chancellor <natechancel...@gmail.com> Signed-off-by: Nicolin Chen <nicoleots...@gmail.com> --- include/linux/dma-contiguous.h | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/include/linux/dma-contiguous.h b/include/linux/dma-contiguous.h index 428f3b7b1c42..c05d4e661489 100644 --- a/include/linux/dma-contiguous.h +++ b/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 device *dev, struct page *pages, 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 -- 2.17.1