From 022387ee1ad34b6ac441ee805604ce9fec782517 Mon Sep 17 00:00:00 2001 From: Julien Grall Date: Sun, 2 Dec 2018 18:54:06 +0000 Subject: [PATCH] xen/arm: mm: Don't open-code Xen PT update in {set, clear}_fixmap() {set, clear}_fixmap() are currently open-coding update to the Xen page-tables. This can be avoided by using the generic helpers map_pages_to_xen() and destroy_xen_mappings(). Both function are not meant to fail for fixmap, hence the BUG_ON() checking the return. Signed-off-by: Julien Grall Reviewed-by: Andrii Anisov Acked-by: Stefano Stabellini --- xen/arch/arm/mm.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/xen/arch/arm/mm.c b/xen/arch/arm/mm.c index 028fbd38ad..46bc3d8075 100644 --- a/xen/arch/arm/mm.c +++ b/xen/arch/arm/mm.c @@ -348,19 +348,19 @@ static inline lpae_t mfn_to_xen_entry(mfn_t mfn, unsigned attr) /* Map a 4k page in a fixmap entry */ void set_fixmap(unsigned map, mfn_t mfn, unsigned int flags) { - lpae_t pte = mfn_to_xen_entry(mfn, PAGE_AI_MASK(flags)); - pte.pt.table = 1; /* 4k mappings always have this bit set */ - pte.pt.xn = 1; - write_pte(xen_fixmap + third_table_offset(FIXMAP_ADDR(map)), pte); - flush_xen_tlb_range_va(FIXMAP_ADDR(map), PAGE_SIZE); + int res; + + res = map_pages_to_xen(FIXMAP_ADDR(map), mfn, 1, flags); + BUG_ON(res != 0); } /* Remove a mapping from a fixmap entry */ void clear_fixmap(unsigned map) { - lpae_t pte = {0}; - write_pte(xen_fixmap + third_table_offset(FIXMAP_ADDR(map)), pte); - flush_xen_tlb_range_va(FIXMAP_ADDR(map), PAGE_SIZE); + int res; + + res = destroy_xen_mappings(FIXMAP_ADDR(map), FIXMAP_ADDR(map) + PAGE_SIZE); + BUG_ON(res != 0); } /* Create Xen's mappings of memory. -- 2.39.5