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| author | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2015-04-24 12:16:40 +0300 |
|---|---|---|
| committer | David Vrabel <david.vrabel@citrix.com> | 2015-05-06 17:02:58 +0300 |
| commit | 8746515d7f04c9ea94cf43e2db1fd2cfca93276d (patch) | |
| tree | d6770d527bfdffc9e9a4fe2f970304a547cde20d /arch/arm/xen | |
| parent | a71dbdaa8ca2933391b08e0ae5567083e3af0892 (diff) | |
| download | linux-8746515d7f04c9ea94cf43e2db1fd2cfca93276d.tar.xz | |
xen: Add __GFP_DMA flag when xen_swiotlb_init gets free pages on ARM
Make sure that xen_swiotlb_init allocates buffers that are DMA capable
when at least one memblock is available below 4G. Otherwise we assume
that all devices on the SoC can cope with >4G addresses. We do this on
ARM and ARM64, where dom0 is mapped 1:1, so pfn == mfn in this case.
No functional changes on x86.
From: Chen Baozi <baozich@gmail.com>
Signed-off-by: Chen Baozi <baozich@gmail.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Tested-by: Chen Baozi <baozich@gmail.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Diffstat (limited to 'arch/arm/xen')
| -rw-r--r-- | arch/arm/xen/mm.c | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index 793551d15f1d..498325074a06 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -4,6 +4,7 @@ #include <linux/gfp.h> #include <linux/highmem.h> #include <linux/export.h> +#include <linux/memblock.h> #include <linux/of_address.h> #include <linux/slab.h> #include <linux/types.h> @@ -21,6 +22,20 @@ #include <asm/xen/hypercall.h> #include <asm/xen/interface.h> +unsigned long xen_get_swiotlb_free_pages(unsigned int order) +{ + struct memblock_region *reg; + gfp_t flags = __GFP_NOWARN; + + for_each_memblock(memory, reg) { + if (reg->base < (phys_addr_t)0xffffffff) { + flags |= __GFP_DMA; + break; + } + } + return __get_free_pages(flags, order); +} + enum dma_cache_op { DMA_UNMAP, DMA_MAP, |