1// Copyright 2016 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5//go:build mips64 || mips64le
6
7#include "textflag.h"
8
9// Set the x_crosscall2_ptr C function pointer variable point to crosscall2.
10// It's such a pointer chain: _crosscall2_ptr -> x_crosscall2_ptr -> crosscall2
11// Use a local trampoline, to avoid taking the address of a dynamically exported
12// function.
13TEXT ·set_crosscall2(SB),NOSPLIT,$0-0
14	MOVV	_crosscall2_ptr(SB), R5
15	MOVV	$crosscall2_trampoline<>(SB), R6
16	MOVV	R6, (R5)
17	RET
18
19TEXT crosscall2_trampoline<>(SB),NOSPLIT,$0-0
20	JMP	crosscall2(SB)
21
22// Called by C code generated by cmd/cgo.
23// func crosscall2(fn, a unsafe.Pointer, n int32, ctxt uintptr)
24// Saves C callee-saved registers and calls cgocallback with three arguments.
25// fn is the PC of a func(a unsafe.Pointer) function.
26TEXT crosscall2(SB),NOSPLIT|NOFRAME,$0
27	/*
28	 * We still need to save all callee save register as before, and then
29	 *  push 3 args for fn (R4, R5, R7), skipping R6.
30	 * Also note that at procedure entry in gc world, 8(R29) will be the
31	 *  first arg.
32	 */
33#ifndef GOMIPS64_softfloat
34	ADDV	$(-8*23), R29
35#else
36	ADDV	$(-8*15), R29
37#endif
38	MOVV	R4, (8*1)(R29) // fn unsafe.Pointer
39	MOVV	R5, (8*2)(R29) // a unsafe.Pointer
40	MOVV	R7, (8*3)(R29) // ctxt uintptr
41	MOVV	R16, (8*4)(R29)
42	MOVV	R17, (8*5)(R29)
43	MOVV	R18, (8*6)(R29)
44	MOVV	R19, (8*7)(R29)
45	MOVV	R20, (8*8)(R29)
46	MOVV	R21, (8*9)(R29)
47	MOVV	R22, (8*10)(R29)
48	MOVV	R23, (8*11)(R29)
49	MOVV	RSB, (8*12)(R29)
50	MOVV	g, (8*13)(R29)
51	MOVV	R31, (8*14)(R29)
52#ifndef GOMIPS64_softfloat
53	MOVD	F24, (8*15)(R29)
54	MOVD	F25, (8*16)(R29)
55	MOVD	F26, (8*17)(R29)
56	MOVD	F27, (8*18)(R29)
57	MOVD	F28, (8*19)(R29)
58	MOVD	F29, (8*20)(R29)
59	MOVD	F30, (8*21)(R29)
60	MOVD	F31, (8*22)(R29)
61#endif
62	// Initialize Go ABI environment
63	// prepare SB register = PC & 0xffffffff00000000
64	BGEZAL	R0, 1(PC)
65	SRLV	$32, R31, RSB
66	SLLV	$32, RSB
67	JAL	runtime·load_g(SB)
68
69	JAL	runtime·cgocallback(SB)
70
71	MOVV	(8*4)(R29), R16
72	MOVV	(8*5)(R29), R17
73	MOVV	(8*6)(R29), R18
74	MOVV	(8*7)(R29), R19
75	MOVV	(8*8)(R29), R20
76	MOVV	(8*9)(R29), R21
77	MOVV	(8*10)(R29), R22
78	MOVV	(8*11)(R29), R23
79	MOVV	(8*12)(R29), RSB
80	MOVV	(8*13)(R29), g
81	MOVV	(8*14)(R29), R31
82#ifndef GOMIPS64_softfloat
83	MOVD	(8*15)(R29), F24
84	MOVD	(8*16)(R29), F25
85	MOVD	(8*17)(R29), F26
86	MOVD	(8*18)(R29), F27
87	MOVD	(8*19)(R29), F28
88	MOVD	(8*20)(R29), F29
89	MOVD	(8*21)(R29), F30
90	MOVD	(8*22)(R29), F31
91	ADDV	$(8*23), R29
92#else
93	ADDV	$(8*15), R29
94#endif
95	RET
96