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authorKonrad Rzeszutek Wilk <konrad.wilk@oracle.com>2016-12-20 10:02:02 -0500
committerKonrad Rzeszutek Wilk <konrad@kernel.org>2017-01-06 13:00:01 -0500
commit7453c549f5f6485c0d79cad7844870dcc7d1b34d (patch)
treed6303358532275cd114b471810d6fc2333780367 /drivers/xen
parentswiotlb: Add swiotlb=noforce debug option (diff)
downloadlinux-dev-7453c549f5f6485c0d79cad7844870dcc7d1b34d.tar.xz
linux-dev-7453c549f5f6485c0d79cad7844870dcc7d1b34d.zip
swiotlb: Export swiotlb_max_segment to users
So they can figure out what is the optimal number of pages that can be contingously stitched together without fear of bounce buffer. We also expose an mechanism for sub-users of SWIOTLB API, such as Xen-SWIOTLB to set the max segment value. And lastly if swiotlb=force is set (which mandates we bounce buffer everything) we set max_segment so at least we can bounce buffer one 4K page instead of a giant 512KB one for which we may not have space. Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Reported-and-Tested-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'drivers/xen')
-rw-r--r--drivers/xen/swiotlb-xen.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/drivers/xen/swiotlb-xen.c b/drivers/xen/swiotlb-xen.c
index aba12009422e..f905d6eeb048 100644
--- a/drivers/xen/swiotlb-xen.c
+++ b/drivers/xen/swiotlb-xen.c
@@ -275,6 +275,10 @@ retry:
rc = 0;
} else
rc = swiotlb_late_init_with_tbl(xen_io_tlb_start, xen_io_tlb_nslabs);
+
+ if (!rc)
+ swiotlb_set_max_segment(PAGE_SIZE);
+
return rc;
error:
if (repeat--) {