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authorJuergen Gross <jgross@suse.com>2019-06-14 07:46:04 +0200
committerJuergen Gross <jgross@suse.com>2019-08-01 06:39:33 +0200
commitb877ac9815a8fe7e5f6d7fdde3dc34652408840a (patch)
tree0b1477601024cd45a16c092feffde094070cf6cd /drivers/xen
parentbf70726668c6116aa4976e0cc87f470be6268a2f (diff)
downloadlinux-b877ac9815a8fe7e5f6d7fdde3dc34652408840a.tar.gz
xen/swiotlb: remember having called xen_create_contiguous_region()
Instead of always calling xen_destroy_contiguous_region() in case the
memory is DMA-able for the used device, do so only in case it has been
made DMA-able via xen_create_contiguous_region() before.

This will avoid a lot of xen_destroy_contiguous_region() calls for
64-bit capable devices.

As the memory in question is owned by swiotlb-xen the PG_owner_priv_1
flag of the first allocated page can be used for remembering.

Signed-off-by: Juergen Gross <jgross@suse.com>
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/swiotlb-xen.c4
1 files changed, 3 insertions, 1 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index 37ddcfcfbb21..ceb681cf64bb 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -322,6 +322,7 @@ xen_swiotlb_alloc_coherent(struct device *hwdev, size_t size,
 			xen_free_coherent_pages(hwdev, size, ret, (dma_addr_t)phys, attrs);
 			return NULL;
 		}
+		SetPageXenRemapped(virt_to_page(ret));
 	}
 	memset(ret, 0, size);
 	return ret;
@@ -346,7 +347,8 @@ xen_swiotlb_free_coherent(struct device *hwdev, size_t size, void *vaddr,
 	size = 1UL << (order + XEN_PAGE_SHIFT);
 
 	if (!WARN_ON((dev_addr + size - 1 > dma_mask) ||
-		     range_straddles_page_boundary(phys, size)))
+		     range_straddles_page_boundary(phys, size)) &&
+	    TestClearPageXenRemapped(virt_to_page(vaddr)))
 		xen_destroy_contiguous_region(phys, order);
 
 	xen_free_coherent_pages(hwdev, size, vaddr, (dma_addr_t)phys, attrs);