xref: /freebsd/sys/contrib/openzfs/module/lua/setjmp/setjmp_mips.S (revision 61145dc2b94f12f6a47344fb9aac702321880e43)
1// SPDX-License-Identifier: BSD-3-Clause
2/*
3 * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
4 *	The President and Fellows of Harvard College.
5 * Copyright (c) 2017 MIPS Technologies, Inc.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 *    notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 *    notice, this list of conditions and the following disclaimer in the
14 *    documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 *    may be used to endorse or promote products derived from this software
17 *    without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32#include <asm/asm.h>
33#include <asm/regdef.h>
34
35/*
36 * setjmp and longjmp for MIPS.
37 */
38
39   .text
40   .set noreorder
41
42   /*
43    * int setjmp(jmp_buf jb);
44    *
45    * Save the current state so we can return again from the call later
46    * if/when longjmp is called. (If the function that called setjmp
47    * returns before longjmp is called, the results are undefined. We
48    * only need to save registers, not the whole contents of the stack.)
49    */
50LEAF(setjmp)
51   /*
52    * jmp_buf is in a0. We need to save s0-s8, sp, gp, and ra in it.
53    * Don't store more registers without adjusting machine/setjmp.h.
54    */
55
56   REG_S sp, 0(a0)		/* save registers */
57   REG_S ra, 1*SZREG(a0)
58   REG_S gp, 2*SZREG(a0)
59   REG_S s0, 3*SZREG(a0)
60   REG_S s1, 4*SZREG(a0)
61   REG_S s2, 5*SZREG(a0)
62   REG_S s3, 6*SZREG(a0)
63   REG_S s4, 7*SZREG(a0)
64   REG_S s5, 8*SZREG(a0)
65   REG_S s6, 9*SZREG(a0)
66   REG_S s7, 10*SZREG(a0)
67   REG_S s8, 11*SZREG(a0)
68
69   jr ra		/* done */
70    move v0, zero	/* return 0 (in delay slot) */
71END(setjmp)
72
73
74   /*
75    * void longjmp(jmp_buf jb, int code);
76    */
77LEAF(longjmp)
78   /*
79    * jmp_buf is in a0. Return code is in a1.
80    * We need to restore s0-s8, sp, gp, and ra from the jmp_buf.
81    * The return code is forced to 1 if 0 is passed in.
82    */
83
84   sltiu t0, a1, 1	/* set t0 to 1 if return code is 0... otherwise 0 */
85   addu a1, a1, t0	/* update the return code */
86
87   REG_L sp, 0(a0)		/* restore registers */
88   REG_L ra, 1*SZREG(a0)
89   REG_L gp, 2*SZREG(a0)
90   REG_L s0, 3*SZREG(a0)
91   REG_L s1, 4*SZREG(a0)
92   REG_L s2, 5*SZREG(a0)
93   REG_L s3, 6*SZREG(a0)
94   REG_L s4, 7*SZREG(a0)
95   REG_L s5, 8*SZREG(a0)
96   REG_L s6, 9*SZREG(a0)
97   REG_L s7, 10*SZREG(a0)
98   REG_L s8, 11*SZREG(a0)
99
100   jr ra		/* return, to where setjmp was called from */
101    move v0, a1		/* set return value */
102END(longjmp)
103
104#ifdef __ELF__
105.section .note.GNU-stack,"",%progbits
106#endif
107