From f5079a9a2a31607a2343e544e9182ce35b030578 Mon Sep 17 00:00:00 2001 From: Stefano Stabellini Date: Fri, 19 Mar 2021 13:01:40 -0700 Subject: 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 Reviewed-by: Boris Ostrovsky Link: https://lore.kernel.org/r/20210319200140.12512-1-sstabellini@kernel.org Signed-off-by: Juergen Gross --- arch/arm/xen/mm.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) (limited to 'arch/arm/xen') 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); -- cgit v1.2.3