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 mips || mipsle
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	MOVW	_crosscall2_ptr(SB), R5
15	MOVW	$crosscall2_trampoline<>(SB), R6
16	MOVW	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, 4(R29) will be the
31	 *  first arg.
32	 */
33
34	// Space for 9 caller-saved GPR + LR + 6 caller-saved FPR.
35	// O32 ABI allows us to smash 16 bytes argument area of caller frame.
36#ifndef GOMIPS_softfloat
37	SUBU	$(4*14+8*6-16), R29
38#else
39	SUBU	$(4*14-16), R29	// For soft-float, no FPR.
40#endif
41	MOVW	R4, (4*1)(R29)	// fn unsafe.Pointer
42	MOVW	R5, (4*2)(R29)	// a unsafe.Pointer
43	MOVW	R7, (4*3)(R29)	// ctxt uintptr
44	MOVW	R16, (4*4)(R29)
45	MOVW	R17, (4*5)(R29)
46	MOVW	R18, (4*6)(R29)
47	MOVW	R19, (4*7)(R29)
48	MOVW	R20, (4*8)(R29)
49	MOVW	R21, (4*9)(R29)
50	MOVW	R22, (4*10)(R29)
51	MOVW	R23, (4*11)(R29)
52	MOVW	g, (4*12)(R29)
53	MOVW	R31, (4*13)(R29)
54#ifndef GOMIPS_softfloat
55	MOVD	F20, (4*14)(R29)
56	MOVD	F22, (4*14+8*1)(R29)
57	MOVD	F24, (4*14+8*2)(R29)
58	MOVD	F26, (4*14+8*3)(R29)
59	MOVD	F28, (4*14+8*4)(R29)
60	MOVD	F30, (4*14+8*5)(R29)
61#endif
62	JAL	runtime·load_g(SB)
63
64	JAL	runtime·cgocallback(SB)
65
66	MOVW	(4*4)(R29), R16
67	MOVW	(4*5)(R29), R17
68	MOVW	(4*6)(R29), R18
69	MOVW	(4*7)(R29), R19
70	MOVW	(4*8)(R29), R20
71	MOVW	(4*9)(R29), R21
72	MOVW	(4*10)(R29), R22
73	MOVW	(4*11)(R29), R23
74	MOVW	(4*12)(R29), g
75	MOVW	(4*13)(R29), R31
76#ifndef GOMIPS_softfloat
77	MOVD	(4*14)(R29), F20
78	MOVD	(4*14+8*1)(R29), F22
79	MOVD	(4*14+8*2)(R29), F24
80	MOVD	(4*14+8*3)(R29), F26
81	MOVD	(4*14+8*4)(R29), F28
82	MOVD	(4*14+8*5)(R29), F30
83
84	ADDU	$(4*14+8*6-16), R29
85#else
86	ADDU	$(4*14-16), R29
87#endif
88	RET
89