From 41fd5d58f9c5c5ee5fa2c8eac153c4cd83cd2676 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Thu, 1 Jul 2021 09:30:45 +0100 Subject: [PATCH] ANDROID: arm64: Add a helper to retrieve the PTE of a fixmap In order to transfer the early mapping state into KVM's MMIO guard infrastucture, provide a small helper that will retrieve the associated PTE. Signed-off-by: Marc Zyngier Bug: 209580772 Change-Id: Iefc1c57d5e9476b718a8a68f60e562a57b09fb6a Signed-off-by: Will Deacon --- arch/arm64/include/asm/fixmap.h | 2 ++ arch/arm64/mm/mmu.c | 15 +++++++++++++++ 2 files changed, 17 insertions(+) diff --git a/arch/arm64/include/asm/fixmap.h b/arch/arm64/include/asm/fixmap.h index 4335800201c9..1aae625b944f 100644 --- a/arch/arm64/include/asm/fixmap.h +++ b/arch/arm64/include/asm/fixmap.h @@ -105,6 +105,8 @@ void __init early_fixmap_init(void); extern void __set_fixmap(enum fixed_addresses idx, phys_addr_t phys, pgprot_t prot); +extern pte_t *__get_fixmap_pte(enum fixed_addresses idx); + #include #endif /* !__ASSEMBLY__ */ diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c index fd85b51b9d50..26af9b7c7f5e 100644 --- a/arch/arm64/mm/mmu.c +++ b/arch/arm64/mm/mmu.c @@ -1286,6 +1286,21 @@ void __set_fixmap(enum fixed_addresses idx, } } +pte_t *__get_fixmap_pte(enum fixed_addresses idx) +{ + unsigned long addr = __fix_to_virt(idx); + pte_t *ptep; + + BUG_ON(idx <= FIX_HOLE || idx >= __end_of_fixed_addresses); + + ptep = fixmap_pte(addr); + + if (!pte_valid(*ptep)) + return NULL; + + return ptep; +} + void *__init fixmap_remap_fdt(phys_addr_t dt_phys, int *size, pgprot_t prot) { const u64 dt_virt_base = __fix_to_virt(FIX_FDT);