diff options
| author | Stefano Stabellini <stefano.stabellini@xilinx.com> | 2021-03-19 13:01:40 -0700 |
|---|---|---|
| committer | Juergen Gross <jgross@suse.com> | 2021-04-23 11:33:50 +0200 |
| commit | f5079a9a2a31607a2343e544e9182ce35b030578 (patch) | |
| tree | 845187f971beecc8c97874a6789a4661e3951056 /arch/arm/xen | |
| parent | a929e124060c448b367f56b28a0c118876147b1f (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/xen')
| -rw-r--r-- | arch/arm/xen/mm.c | 14 |
1 files changed, 13 insertions, 1 deletions
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); |