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Diffstat (limited to 'src/runtime/cgo/asm_ppc64x.s')
| -rw-r--r-- | src/runtime/cgo/asm_ppc64x.s | 70 |
1 files changed, 70 insertions, 0 deletions
diff --git a/src/runtime/cgo/asm_ppc64x.s b/src/runtime/cgo/asm_ppc64x.s new file mode 100644 index 0000000..a389745 --- /dev/null +++ b/src/runtime/cgo/asm_ppc64x.s @@ -0,0 +1,70 @@ +// Copyright 2014 The Go Authors. All rights reserved. +// Use of this source code is governed by a BSD-style +// license that can be found in the LICENSE file. + +//go:build ppc64 || ppc64le + +#include "textflag.h" +#include "asm_ppc64x.h" +#include "abi_ppc64x.h" + +#ifdef GO_PPC64X_HAS_FUNCDESC +// crosscall2 is marked with go:cgo_export_static. On AIX, this creates and exports +// the symbol name and descriptor as the AIX linker expects, but does not work if +// referenced from within Go. Create and use an aliased descriptor of crosscall2 +// to workaround this. +DEFINE_PPC64X_FUNCDESC(_crosscall2<>, crosscall2) +#define CROSSCALL2_FPTR $_crosscall2<>(SB) +#else +// Use a local trampoline, to avoid taking the address of a dynamically exported +// function. +#define CROSSCALL2_FPTR $crosscall2_trampoline<>(SB) +#endif + +// Set the x_crosscall2_ptr C function pointer variable point to crosscall2. +// It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2 +TEXT ·set_crosscall2(SB),NOSPLIT,$0-0 + MOVD _crosscall2_ptr(SB), R5 + MOVD CROSSCALL2_FPTR, R6 + MOVD R6, (R5) + RET + +TEXT crosscall2_trampoline<>(SB),NOSPLIT,$0-0 + JMP crosscall2(SB) + +// Called by C code generated by cmd/cgo. +// func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr) +// Saves C callee-saved registers and calls cgocallback with three arguments. +// fn is the PC of a func(a unsafe.Pointer) function. +// The value of R2 is saved on the new stack frame, and not +// the caller's frame due to issue #43228. +TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0 + // Start with standard C stack frame layout and linkage, allocate + // 32 bytes of argument space, save callee-save regs, and set R0 to $0. + STACK_AND_SAVE_HOST_TO_GO_ABI(32) + // The above will not preserve R2 (TOC). Save it in case Go is + // compiled without a TOC pointer (e.g -buildmode=default). + MOVD R2, 24(R1) + + // Load the current g. + BL runtime·load_g(SB) + +#ifdef GO_PPC64X_HAS_FUNCDESC + // Load the real entry address from the first slot of the function descriptor. + // The first argument fn might be null, that means dropm in pthread key destructor. + CMP R3, $0 + BEQ nil_fn + MOVD 8(R3), R2 + MOVD (R3), R3 +nil_fn: +#endif + MOVD R3, FIXED_FRAME+0(R1) // fn unsafe.Pointer + MOVD R4, FIXED_FRAME+8(R1) // a unsafe.Pointer + // Skip R5 = n uint32 + MOVD R6, FIXED_FRAME+16(R1) // ctxt uintptr + BL runtime·cgocallback(SB) + + // Restore the old frame, and R2. + MOVD 24(R1), R2 + UNSTACK_AND_RESTORE_GO_TO_HOST_ABI(32) + RET |