mirror of
https://sourceware.org/git/glibc.git
synced 2024-11-22 21:10:07 +00:00
d3c32ae207
The runtime support routines for the call ABI of the Scalable Matrix Extension (SME) are mostly in libgcc. Since libc.so cannot depend on libgcc_s.so have an implementation of __arm_za_disable in libc for libc internal use in longjmp and similar APIs. __libc_arm_za_disable follows the same PCS rules as __arm_za_disable, but it's a hidden symbol so it does not need variant PCS marking. Using __libc_fatal instead of abort because it can print a message and works in ld.so too. But for now we don't need SME routines in ld.so. To check the SME HWCAP in asm, we need the _dl_hwcap2 member offset in _rtld_global_ro in the shared libc.so, while in libc.a the _dl_hwcap2 object is accessed. Reviewed-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>
113 lines
3.4 KiB
ArmAsm
113 lines
3.4 KiB
ArmAsm
/* Libc internal support routine for SME.
|
|
Copyright (C) 2023 Free Software Foundation, Inc.
|
|
|
|
This file is part of the GNU C Library.
|
|
|
|
The GNU C Library is free software; you can redistribute it and/or
|
|
modify it under the terms of the GNU Lesser General Public
|
|
License as published by the Free Software Foundation; either
|
|
version 2.1 of the License, or (at your option) any later version.
|
|
|
|
The GNU C Library is distributed in the hope that it will be useful,
|
|
but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
|
|
Lesser General Public License for more details.
|
|
|
|
You should have received a copy of the GNU Lesser General Public
|
|
License along with the GNU C Library. If not, see
|
|
<http://www.gnu.org/licenses/>. */
|
|
|
|
#include <sysdep.h>
|
|
#include <rtld-global-offsets.h>
|
|
|
|
#define HWCAP2_SME_BIT 23
|
|
|
|
/* Disable ZA. Call ABI:
|
|
- Private ZA, streaming-compatible.
|
|
- x0-x13, x19-x29, sp and fp regs are call preserved.
|
|
- On return tpidr2_el0 = 0, ZA = 0.
|
|
- Takes no argument.
|
|
- Does not return a value.
|
|
- Can abort on failure (then registers are not preserved). */
|
|
|
|
ENTRY (__libc_arm_za_disable)
|
|
|
|
/* Check if SME is available. */
|
|
#ifdef SHARED
|
|
/* In libc.so. */
|
|
adrp x14, :got:_rtld_global_ro
|
|
ldr x14, [x14, :got_lo12:_rtld_global_ro]
|
|
ldr x14, [x14, GLRO_DL_HWCAP2_OFFSET]
|
|
#else
|
|
/* In libc.a, may be PIC. */
|
|
adrp x14, _dl_hwcap2
|
|
ldr x14, [x14, :lo12:_dl_hwcap2]
|
|
#endif
|
|
tbz x14, HWCAP2_SME_BIT, L(end)
|
|
|
|
.inst 0xd53bd0ae /* mrs x14, tpidr2_el0 */
|
|
cbz x14, L(end)
|
|
|
|
/* Check reserved bytes, abort on unknown extensions. */
|
|
ldrh w15, [x14, 10]
|
|
ldr w16, [x14, 12]
|
|
orr w15, w15, w16
|
|
cbnz w15, L(fail)
|
|
|
|
ldr x16, [x14]
|
|
cbz x16, L(end)
|
|
ldrh w17, [x14, 8]
|
|
cbz w17, L(end)
|
|
|
|
/* x14: tpidr2, x15: 0,
|
|
x16: za_save_buffer, x17: num_za_save_slices. */
|
|
|
|
L(save_loop):
|
|
.inst 0xe1206200 /* str za[w15, 0], [x16] */
|
|
.inst 0xe1206201 /* str za[w15, 1], [x16, 1, mul vl] */
|
|
.inst 0xe1206202 /* str za[w15, 2], [x16, 2, mul vl] */
|
|
.inst 0xe1206203 /* str za[w15, 3], [x16, 3, mul vl] */
|
|
.inst 0xe1206204 /* str za[w15, 4], [x16, 4, mul vl] */
|
|
.inst 0xe1206205 /* str za[w15, 5], [x16, 5, mul vl] */
|
|
.inst 0xe1206206 /* str za[w15, 6], [x16, 6, mul vl] */
|
|
.inst 0xe1206207 /* str za[w15, 7], [x16, 7, mul vl] */
|
|
.inst 0xe1206208 /* str za[w15, 8], [x16, 8, mul vl] */
|
|
.inst 0xe1206209 /* str za[w15, 9], [x16, 9, mul vl] */
|
|
.inst 0xe120620a /* str za[w15, 10], [x16, 10, mul vl] */
|
|
.inst 0xe120620b /* str za[w15, 11], [x16, 11, mul vl] */
|
|
.inst 0xe120620c /* str za[w15, 12], [x16, 12, mul vl] */
|
|
.inst 0xe120620d /* str za[w15, 13], [x16, 13, mul vl] */
|
|
.inst 0xe120620e /* str za[w15, 14], [x16, 14, mul vl] */
|
|
.inst 0xe120620f /* str za[w15, 15], [x16, 15, mul vl] */
|
|
add w15, w15, 16
|
|
.inst 0x04305a10 /* addsvl x16, x16, 16 */
|
|
cmp w17, w15
|
|
bhi L(save_loop)
|
|
.inst 0xd51bd0bf /* msr tpidr2_el0, xzr */
|
|
.inst 0xd503447f /* smstop za */
|
|
L(end):
|
|
ret
|
|
L(fail):
|
|
#if HAVE_AARCH64_PAC_RET
|
|
PACIASP
|
|
cfi_window_save
|
|
#endif
|
|
stp x29, x30, [sp, -32]!
|
|
cfi_adjust_cfa_offset (32)
|
|
cfi_rel_offset (x29, 0)
|
|
cfi_rel_offset (x30, 8)
|
|
mov x29, sp
|
|
.inst 0x04e0e3f0 /* cntd x16 */
|
|
str x16, [sp, 16]
|
|
cfi_rel_offset (46, 16)
|
|
.inst 0xd503467f /* smstop */
|
|
adrp x0, L(msg)
|
|
add x0, x0, :lo12:L(msg)
|
|
bl HIDDEN_JUMPTARGET (__libc_fatal)
|
|
END (__libc_arm_za_disable)
|
|
|
|
.section .rodata
|
|
.align 3
|
|
L(msg):
|
|
.string "FATAL: __libc_arm_za_disable failed.\n"
|