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| author | Stefano Stabellini <stefano.stabellini@eu.citrix.com> | 2014-11-21 11:07:39 +0000 |
|---|---|---|
| committer | Luis Henriques <luis.henriques@canonical.com> | 2015-01-16 14:34:36 +0000 |
| commit | 342443e998bd2dd6406d46c5f7e62540a6d4a170 (patch) | |
| tree | 148c65c321d7c967f2b63a998df35204d748d203 /drivers/xen | |
| parent | 648d9a76555a063a16ddbff6f62e699cda5fd1e5 (diff) | |
| download | linux-stable-342443e998bd2dd6406d46c5f7e62540a6d4a170.tar.gz linux-stable-342443e998bd2dd6406d46c5f7e62540a6d4a170.tar.bz2 linux-stable-342443e998bd2dd6406d46c5f7e62540a6d4a170.zip | |
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>
[ stefano: The commit needs to be slightly modified because
is_device_dma_coherent is not available on kernels < 3.19, so I just
removed the call, thus assuming that the device is not coherent on arm
(slower but safe) ]
Cc: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
[ luis: backported to 3.16: used backport by stefano ]
Signed-off-by: Luis Henriques <luis.henriques@canonical.com>
Diffstat (limited to 'drivers/xen')
| -rw-r--r-- | drivers/xen/swiotlb-xen.c | 5 |
1 files changed, 4 insertions, 1 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c index 9df5d6ec7eec..de37cc22b9a5 100644 --- a/drivers/xen/swiotlb-xen.c +++ b/drivers/xen/swiotlb-xen.c @@ -397,7 +397,9 @@ dma_addr_t xen_swiotlb_map_page(struct device *dev, struct page *page, * buffering it. */ if (dma_capable(dev, dev_addr, size) && - !range_straddles_page_boundary(phys, size) && !swiotlb_force) { + !range_straddles_page_boundary(phys, size) && + !xen_arch_need_swiotlb(dev, PFN_DOWN(phys), PFN_DOWN(dev_addr)) && + !swiotlb_force) { /* we are not interested in the dma_addr returned by * xen_dma_map_page, only in the potential cache flushes executed * by the function. */ @@ -555,6 +557,7 @@ xen_swiotlb_map_sg_attrs(struct device *hwdev, struct scatterlist *sgl, dma_addr_t dev_addr = xen_phys_to_bus(paddr); if (swiotlb_force || + xen_arch_need_swiotlb(hwdev, PFN_DOWN(paddr), PFN_DOWN(dev_addr)) || !dma_capable(hwdev, dev_addr, sg->length) || range_straddles_page_boundary(paddr, sg->length)) { phys_addr_t map = swiotlb_tbl_map_single(hwdev, |