Commit ca407c72 authored by Ard Biesheuvel's avatar Ard Biesheuvel Committed by mergify[bot]
Browse files

ArmPkg/CompilerIntrinsicsLib: provide atomics intrinsics

Gary reports the GCC 10 will emit calls to atomics intrinsics routines
unless -mno-outline-atomics is specified. This means GCC-10 introduces
new intrinsics, and even though it would be possible to work around this
by specifying the command line option, this would require a new GCC10
toolchain profile to be created, which we prefer to avoid.

So instead, add the new intrinsics to our library so they are provided
when necessary.
Signed-off-by: default avatarArd Biesheuvel <>
Tested-by: default avatarGary Lin <>
Acked-by: default avatarLaszlo Ersek <>
Reviewed-by: default avatarLeif Lindholm <>
Reviewed-by: default avatarPhilippe Mathieu-Daude <>
parent 4403bbd7
# Copyright (c) 2020, Arm, Limited. All rights reserved.<BR>
# SPDX-License-Identifier: BSD-2-Clause-Patent
* Provide the GCC intrinsics that are required when using GCC 9 or
* later with the -moutline-atomics options (which became the default
* in GCC 10)
.arch armv8-a
.macro reg_alias, pfx, sz
r0_\sz .req \pfx\()0
r1_\sz .req \pfx\()1
tmp0_\sz .req \pfx\()16
tmp1_\sz .req \pfx\()17
* Define register aliases of the right type for each size
* (xN for 8 bytes, wN for everything smaller)
reg_alias w, 1
reg_alias w, 2
reg_alias w, 4
reg_alias x, 8
.macro fn_start, name:req
.section .text.\name
.globl \name
.type \name, %function
.macro fn_end, name:req
.size \name, . - \name
* Emit an atomic helper for \model with operands of size \sz, using
* the operation specified by \insn (which is the LSE name), and which
* can be implemented using the generic load-locked/store-conditional
* (LL/SC) sequence below, using the arithmetic operation given by
* \opc.
.macro emit_ld_sz, sz:req, insn:req, opc:req, model:req, s, a, l
fn_start __aarch64_\insn\()\sz\()\model
mov tmp0_\sz, r0_\sz
0: ld\a\()xr\s r0_\sz, [x1]
.ifnc \insn, swp
\opc tmp1_\sz, r0_\sz, tmp0_\sz
st\l\()xr\s w15, tmp1_\sz, [x1]
st\l\()xr\s w15, tmp0_\sz, [x1]
cbnz w15, 0b
fn_end __aarch64_\insn\()\sz\()\model
* Emit atomic helpers for \model for operand sizes in the
* set {1, 2, 4, 8}, for the instruction pattern given by
* \insn. (This is the LSE name, but this implementation uses
* the generic LL/SC sequence using \opc as the arithmetic
* operation on the target.)
.macro emit_ld, insn:req, opc:req, model:req, a, l
emit_ld_sz 1, \insn, \opc, \model, b, \a, \l
emit_ld_sz 2, \insn, \opc, \model, h, \a, \l
emit_ld_sz 4, \insn, \opc, \model, , \a, \l
emit_ld_sz 8, \insn, \opc, \model, , \a, \l
* Emit the compare and swap helper for \model and size \sz
* using LL/SC instructions.
.macro emit_cas_sz, sz:req, model:req, uxt:req, s, a, l
fn_start __aarch64_cas\sz\()\model
\uxt tmp0_\sz, r0_\sz
0: ld\a\()xr\s r0_\sz, [x2]
cmp r0_\sz, tmp0_\sz
bne 1f
st\l\()xr\s w15, r1_\sz, [x2]
cbnz w15, 0b
1: ret
fn_end __aarch64_cas\sz\()\model
* Emit compare-and-swap helpers for \model for operand sizes in the
* set {1, 2, 4, 8, 16}.
.macro emit_cas, model:req, a, l
emit_cas_sz 1, \model, uxtb, b, \a, \l
emit_cas_sz 2, \model, uxth, h, \a, \l
emit_cas_sz 4, \model, mov , , \a, \l
emit_cas_sz 8, \model, mov , , \a, \l
* We cannot use the parameterized sequence for 16 byte CAS, so we
* need to define it explicitly.
fn_start __aarch64_cas16\model
mov x16, x0
mov x17, x1
0: ld\a\()xp x0, x1, [x4]
cmp x0, x16
ccmp x1, x17, #0, eq
bne 1f
st\l\()xp w15, x16, x17, [x4]
cbnz w15, 0b
1: ret
fn_end __aarch64_cas16\model
* Emit the set of GCC outline atomic helper functions for
* the memory ordering model given by \model:
* - relax unordered loads and stores
* - acq load-acquire, unordered store
* - rel unordered load, store-release
* - acq_rel load-acquire, store-release
.macro emit_model, model:req, a, l
emit_ld ldadd, add, \model, \a, \l
emit_ld ldclr, bic, \model, \a, \l
emit_ld ldeor, eor, \model, \a, \l
emit_ld ldset, orr, \model, \a, \l
emit_ld swp, mov, \model, \a, \l
emit_cas \model, \a, \l
emit_model _relax
emit_model _acq, a
emit_model _rel,, l
emit_model _acq_rel, a, l
......@@ -79,6 +79,9 @@
Arm/ldivmod.asm | MSFT
Arm/llsr.asm | MSFT
AArch64/Atomics.S | GCC
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