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authorStefano Stabellini <stefano.stabellini@xilinx.com>2021-03-19 13:01:40 -0700
committerJuergen Gross <jgross@suse.com>2021-04-23 11:33:50 +0200
commitf5079a9a2a31607a2343e544e9182ce35b030578 (patch)
tree845187f971beecc8c97874a6789a4661e3951056 /arch/arm
parenta929e124060c448b367f56b28a0c118876147b1f (diff)
xen/arm: introduce XENFEAT_direct_mapped and XENFEAT_not_direct_mapped
Newer Xen versions expose two Xen feature flags to tell us if the domain is directly mapped or not. Only when a domain is directly mapped it makes sense to enable swiotlb-xen on ARM. Introduce a function on ARM to check the new Xen feature flags and also to deal with the legacy case. Call the function xen_swiotlb_detect. Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20210319200140.12512-1-sstabellini@kernel.org Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch/arm')
-rw-r--r--arch/arm/include/asm/xen/swiotlb-xen.h1
-rw-r--r--arch/arm/xen/mm.c14
2 files changed, 14 insertions, 1 deletions
diff --git a/arch/arm/include/asm/xen/swiotlb-xen.h b/arch/arm/include/asm/xen/swiotlb-xen.h
new file mode 100644
index 000000000000..455ade5d5320
--- /dev/null
+++ b/arch/arm/include/asm/xen/swiotlb-xen.h
@@ -0,0 +1 @@
+#include <xen/arm/swiotlb-xen.h>
diff --git a/arch/arm/xen/mm.c b/arch/arm/xen/mm.c
index 467fa225c3d0..e1b12b242a32 100644
--- a/arch/arm/xen/mm.c
+++ b/arch/arm/xen/mm.c
@@ -135,10 +135,22 @@ void xen_destroy_contiguous_region(phys_addr_t pstart, unsigned int order)
return;
}
+int xen_swiotlb_detect(void)
+{
+ if (!xen_domain())
+ return 0;
+ if (xen_feature(XENFEAT_direct_mapped))
+ return 1;
+ /* legacy case */
+ if (!xen_feature(XENFEAT_not_direct_mapped) && xen_initial_domain())
+ return 1;
+ return 0;
+}
+
static int __init xen_mm_init(void)
{
struct gnttab_cache_flush cflush;
- if (!xen_initial_domain())
+ if (!xen_swiotlb_detect())
return 0;
xen_swiotlb_init(1, false);