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Diffstat (limited to 'MdePkg/Library/CompilerIntrinsicsLib/AArch64/Atomics.S')
| -rw-r--r-- | MdePkg/Library/CompilerIntrinsicsLib/AArch64/Atomics.S | 142 |
1 files changed, 142 insertions, 0 deletions
diff --git a/MdePkg/Library/CompilerIntrinsicsLib/AArch64/Atomics.S b/MdePkg/Library/CompilerIntrinsicsLib/AArch64/Atomics.S new file mode 100644 index 0000000000..3792020ab8 --- /dev/null +++ b/MdePkg/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
+ st\l\()xr\s w15, tmp1_\sz, [x1]
+ .else
+ st\l\()xr\s w15, tmp0_\sz, [x1]
+ .endif
+ cbnz w15, 0b
+ ret
+ fn_end __aarch64_\insn\()\sz\()\model
+ .endm
+
+ /*
+ * 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
+ .endm
+
+ /*
+ * 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
+ .endm
+
+ /*
+ * 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
+ .endm
+
+ /*
+ * 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
+ .endm
+
+ emit_model _relax
+ emit_model _acq, a
+ emit_model _rel,, l
+ emit_model _acq_rel, a, l
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