diff options
Diffstat (limited to 'arch/arm64/include/asm/efi.h')
| -rw-r--r-- | arch/arm64/include/asm/efi.h | 26 |
1 files changed, 25 insertions, 1 deletions
diff --git a/arch/arm64/include/asm/efi.h b/arch/arm64/include/asm/efi.h index 771b3f0bc757..0b6b1633017f 100644 --- a/arch/arm64/include/asm/efi.h +++ b/arch/arm64/include/asm/efi.h @@ -1,6 +1,7 @@ #ifndef _ASM_EFI_H #define _ASM_EFI_H +#include <asm/cpufeature.h> #include <asm/io.h> #include <asm/mmu_context.h> #include <asm/neon.h> @@ -78,7 +79,30 @@ static inline void efifb_setup_from_dmi(struct screen_info *si, const char *opt) static inline void efi_set_pgd(struct mm_struct *mm) { - switch_mm(NULL, mm, NULL); + __switch_mm(mm); + + if (system_uses_ttbr0_pan()) { + if (mm != current->active_mm) { + /* + * Update the current thread's saved ttbr0 since it is + * restored as part of a return from exception. Set + * the hardware TTBR0_EL1 using cpu_switch_mm() + * directly to enable potential errata workarounds. + */ + update_saved_ttbr0(current, mm); + cpu_switch_mm(mm->pgd, mm); + } else { + /* + * Defer the switch to the current thread's TTBR0_EL1 + * until uaccess_enable(). Restore the current + * thread's saved ttbr0 corresponding to its active_mm + * (if different from init_mm). + */ + cpu_set_reserved_ttbr0(); + if (current->active_mm != &init_mm) + update_saved_ttbr0(current, current->active_mm); + } + } } void efi_virtmap_load(void); |