diff options
| author | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2014-11-21 11:07:39 +0000 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2015-02-05 22:36:10 -0800 |
| commit | a6df13631781815752638547a49222610929f89e (patch) | |
| tree | aef6ba965b3b4aa5513c914fd28dc440eda5f275 /arch/arm/xen/mm.c | |
| parent | b2f21d1b7bc80150f2b7d1fecae5f64c9ead26fa (diff) | |
xen/arm/arm64: introduce xen_arch_need_swiotlb
commit a4dba130891271084344c12537731542ec77cb85 upstream.
Introduce an arch specific function to find out whether a particular dma
mapping operation needs to bounce on the swiotlb buffer.
On ARM and ARM64, if the page involved is a foreign page and the device
is not coherent, we need to bounce because at unmap time we cannot
execute any required cache maintenance operations (we don't know how to
find the pfn from the mfn).
No change of behaviour for x86.
Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Reviewed-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'arch/arm/xen/mm.c')
| -rw-r--r-- | arch/arm/xen/mm.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c index b0e77de99148..f8a576b1d9bb 100644 --- a/arch/arm/xen/mm.c +++ b/arch/arm/xen/mm.c @@ -16,6 +16,13 @@ #include <asm/xen/hypercall.h> #include <asm/xen/interface.h> +bool xen_arch_need_swiotlb(struct device *dev, + unsigned long pfn, + unsigned long mfn) +{ + return (pfn != mfn); +} + int xen_create_contiguous_region(phys_addr_t pstart, unsigned int order, unsigned int address_bits, dma_addr_t *dma_handle) |