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: Ard Biesheuvel <ard.biesheu...@arm.com>
---
v2:
- add missing .globl to export the functions from the object file
- add function end markers so the size of each is visible in the
ELF metadata
- add some comments to describe what is going on
ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf |
3 +
ArmPkg/Library/CompilerIntrinsicsLib/AArch64/Atomics.S |
142 ++++++++++++++++++++
2 files changed, 145 insertions(+)
diff --git
a/ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
b/ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
index d5bad9467758..fcf48c678119 100644
--- a/ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
+++ b/ArmPkg/Library/CompilerIntrinsicsLib/CompilerIntrinsicsLib.inf
@@ -79,6 +79,9 @@ [Sources.ARM]
Arm/ldivmod.asm | MSFT
Arm/llsr.asm | MSFT
+[Sources.AARCH64]
+ AArch64/Atomics.S | GCC
+
[Packages]
MdePkg/MdePkg.dec
ArmPkg/ArmPkg.dec
diff --git
a/ArmPkg/Library/CompilerIntrinsicsLib/AArch64/Atomics.S
b/ArmPkg/Library/CompilerIntrinsicsLib/AArch64/Atomics.S
new file mode 100644
index 000000000000..dc61d6bb8e52
--- /dev/null
+++ b/ArmPkg/Library/CompilerIntrinsicsLib/AArch64/Atomics.S
@@ -0,0 +1,142 @@
+#------------------------------------------------------------------------------
+#
+# 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
+ .endm
+
+ /*
+ * 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
+\name\():
+ .endm
+
+ .macro fn_end, name:req
+ .size \name, . - \name
+ .endm
+
+ /*
+ * 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
+ .else
+ \opc tmp1_\sz, tmp0_\sz
+ .endif
+ st\l\()xr\s w15, tmp1_\sz, [x1]
+ cbnz w15, 0b
