diff options
| author | Kirill A. Shutemov <kirill.shutemov@linux.intel.com> | 2023-03-12 14:26:03 +0300 |
|---|---|---|
| committer | Dave Hansen <dave.hansen@linux.intel.com> | 2023-03-16 13:08:39 -0700 |
| commit | 2f8794bd087e7958c8d1f0a0538856ca03e0bf3c (patch) | |
| tree | fb0d64dff58561c2b5f71f6ebfe30aa0bd6b41b7 /arch/x86/include/asm/mmu.h | |
| parent | e0bddc19ba9578bc4e4c60a3f29ccc227277854c (diff) | |
x86/mm: Provide arch_prctl() interface for LAM
Add a few of arch_prctl() handles:
- ARCH_ENABLE_TAGGED_ADDR enabled LAM. The argument is required number
of tag bits. It is rounded up to the nearest LAM mode that can
provide it. For now only LAM_U57 is supported, with 6 tag bits.
- ARCH_GET_UNTAG_MASK returns untag mask. It can indicates where tag
bits located in the address.
- ARCH_GET_MAX_TAG_BITS returns the maximum tag bits user can request.
Zero if LAM is not supported.
Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com>
Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Alexander Potapenko <glider@google.com>
Link: https://lore.kernel.org/all/20230312112612.31869-9-kirill.shutemov%40linux.intel.com
Diffstat (limited to 'arch/x86/include/asm/mmu.h')
| -rw-r--r-- | arch/x86/include/asm/mmu.h | 2 |
1 files changed, 2 insertions, 0 deletions
diff --git a/arch/x86/include/asm/mmu.h b/arch/x86/include/asm/mmu.h index 9cac8c45a647..e80762e998ce 100644 --- a/arch/x86/include/asm/mmu.h +++ b/arch/x86/include/asm/mmu.h @@ -12,6 +12,8 @@ #define MM_CONTEXT_UPROBE_IA32 0 /* vsyscall page is accessible on this MM */ #define MM_CONTEXT_HAS_VSYSCALL 1 +/* Do not allow changing LAM mode */ +#define MM_CONTEXT_LOCK_LAM 2 /* * x86 has arch-specific MMU state beyond what lives in mm_struct. |