From 93116842895ec062e3e700f00477bb6c7f3b09ee Mon Sep 17 00:00:00 2001 From: Will Deacon Date: Tue, 3 Apr 2018 12:09:00 +0100 Subject: [PATCH] arm64: mm: Add arm64_kernel_unmapped_at_el0 helper commit fc0e1299da54 upstream. In order for code such as TLB invalidation to operate efficiently when the decision to map the kernel at EL0 is determined at runtime, this patch introduces a helper function, arm64_kernel_unmapped_at_el0, to determine whether or not the kernel is mapped whilst running in userspace. Currently, this just reports the value of CONFIG_UNMAP_KERNEL_AT_EL0, but will later be hooked up to a fake CPU capability using a static key. Reviewed-by: Mark Rutland Tested-by: Laura Abbott Tested-by: Shanker Donthineni Signed-off-by: Will Deacon Signed-off-by: Alex Shi [v4.9 backport] Signed-off-by: Mark Rutland [v4.9 backport] Tested-by: Will Deacon Tested-by: Greg Hackmann Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/mmu.h | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h index 49924e56048e..279e75b8a49e 100644 --- a/arch/arm64/include/asm/mmu.h +++ b/arch/arm64/include/asm/mmu.h @@ -18,6 +18,8 @@ #define USER_ASID_FLAG (UL(1) << 48) +#ifndef __ASSEMBLY__ + typedef struct { atomic64_t id; void *vdso; @@ -30,6 +32,11 @@ typedef struct { */ #define ASID(mm) ((mm)->context.id.counter & 0xffff) +static inline bool arm64_kernel_unmapped_at_el0(void) +{ + return IS_ENABLED(CONFIG_UNMAP_KERNEL_AT_EL0); +} + extern void paging_init(void); extern void bootmem_init(void); extern void __iomem *early_io_map(phys_addr_t phys, unsigned long virt); @@ -39,4 +46,5 @@ extern void create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys, pgprot_t prot, bool allow_block_mappings); extern void *fixmap_remap_fdt(phys_addr_t dt_phys); +#endif /* !__ASSEMBLY__ */ #endif