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authorStefano Stabellini <stefano.stabellini@eu.citrix.com>2015-04-24 10:16:40 +0100
committerDavid Vrabel <david.vrabel@citrix.com>2015-05-06 15:02:58 +0100
commit8746515d7f04c9ea94cf43e2db1fd2cfca93276d (patch)
treed6770d527bfdffc9e9a4fe2f970304a547cde20d /arch/arm/xen
parenta71dbdaa8ca2933391b08e0ae5567083e3af0892 (diff)
downloadblackbird-op-linux-8746515d7f04c9ea94cf43e2db1fd2cfca93276d.tar.gz
blackbird-op-linux-8746515d7f04c9ea94cf43e2db1fd2cfca93276d.zip
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.c15
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,
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