From: Will Deacon will.deacon@arm.com
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 mark.rutland@arm.com Tested-by: Laura Abbott labbott@redhat.com Tested-by: Shanker Donthineni shankerd@codeaurora.org Signed-off-by: Will Deacon will.deacon@arm.com (cherry picked from commit fc0e1299da548b32440051f58f08e0c1eb7edd0b) Signed-off-by: Alex Shi alex.shi@linaro.org --- 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 49924e5..279e75b 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