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authorWill Deacon <will.deacon@arm.com>2017-11-14 13:58:08 +0000
committerWill Deacon <will.deacon@arm.com>2017-12-11 13:40:41 +0000
commitfc0e1299da548b32440051f58f08e0c1eb7edd0b (patch)
treef902f679c6a7a3ca503052676e28c2358e9478a0 /arch/arm64
parent0c8ea531b7740754cf374ca8b7510655f569c5e3 (diff)
downloadlinux-fc0e1299da548b32440051f58f08e0c1eb7edd0b.tar.bz2
arm64: mm: Add arm64_kernel_unmapped_at_el0 helper
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>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/include/asm/mmu.h8
1 files changed, 8 insertions, 0 deletions
diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
index 01bfb184f2a8..c07954638658 100644
--- a/arch/arm64/include/asm/mmu.h
+++ b/arch/arm64/include/asm/mmu.h
@@ -19,6 +19,8 @@
#define MMCF_AARCH32 0x1 /* mm context flag for AArch32 executables */
#define USER_ASID_FLAG (UL(1) << 48)
+#ifndef __ASSEMBLY__
+
typedef struct {
atomic64_t id;
void *vdso;
@@ -32,6 +34,11 @@ 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);
@@ -42,4 +49,5 @@ extern void create_pgd_mapping(struct mm_struct *mm, phys_addr_t phys,
extern void *fixmap_remap_fdt(phys_addr_t dt_phys);
extern void mark_linear_text_alias_ro(void);
+#endif /* !__ASSEMBLY__ */
#endif