xref: /freebsd/sys/contrib/openzfs/module/lua/setjmp/setjmp_mips.S (revision 7ec2f6bce5d28e6662c29e63f6ab6b7ef57d98b2)
1/*
2 * Copyright (c) 2000, 2001, 2002, 2003, 2004, 2005, 2008, 2009
3 *	The President and Fellows of Harvard College.
4 * Copyright (c) 2017 MIPS Technologies, Inc.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 *    notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 * 3. Neither the name of the University nor the names of its contributors
15 *    may be used to endorse or promote products derived from this software
16 *    without specific prior written permission.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE UNIVERSITY AND CONTRIBUTORS ``AS IS'' AND
19 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
20 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
21 * ARE DISCLAIMED.  IN NO EVENT SHALL THE UNIVERSITY OR CONTRIBUTORS BE LIABLE
22 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
23 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
24 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
25 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
26 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
27 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
28 * SUCH DAMAGE.
29 */
30
31#include <asm/asm.h>
32#include <asm/regdef.h>
33
34/*
35 * setjmp and longjmp for MIPS.
36 */
37
38   .text
39   .set noreorder
40
41   /*
42    * int setjmp(jmp_buf jb);
43    *
44    * Save the current state so we can return again from the call later
45    * if/when longjmp is called. (If the function that called setjmp
46    * returns before longjmp is called, the results are undefined. We
47    * only need to save registers, not the whole contents of the stack.)
48    */
49LEAF(setjmp)
50   /*
51    * jmp_buf is in a0. We need to save s0-s8, sp, gp, and ra in it.
52    * Don't store more registers without adjusting machine/setjmp.h.
53    */
54
55   REG_S sp, 0(a0)		/* save registers */
56   REG_S ra, 1*SZREG(a0)
57   REG_S gp, 2*SZREG(a0)
58   REG_S s0, 3*SZREG(a0)
59   REG_S s1, 4*SZREG(a0)
60   REG_S s2, 5*SZREG(a0)
61   REG_S s3, 6*SZREG(a0)
62   REG_S s4, 7*SZREG(a0)
63   REG_S s5, 8*SZREG(a0)
64   REG_S s6, 9*SZREG(a0)
65   REG_S s7, 10*SZREG(a0)
66   REG_S s8, 11*SZREG(a0)
67
68   jr ra		/* done */
69    move v0, zero	/* return 0 (in delay slot) */
70END(setjmp)
71
72
73   /*
74    * void longjmp(jmp_buf jb, int code);
75    */
76LEAF(longjmp)
77   /*
78    * jmp_buf is in a0. Return code is in a1.
79    * We need to restore s0-s8, sp, gp, and ra from the jmp_buf.
80    * The return code is forced to 1 if 0 is passed in.
81    */
82
83   sltiu t0, a1, 1	/* set t0 to 1 if return code is 0... otherwise 0 */
84   addu a1, a1, t0	/* update the return code */
85
86   REG_L sp, 0(a0)		/* restore registers */
87   REG_L ra, 1*SZREG(a0)
88   REG_L gp, 2*SZREG(a0)
89   REG_L s0, 3*SZREG(a0)
90   REG_L s1, 4*SZREG(a0)
91   REG_L s2, 5*SZREG(a0)
92   REG_L s3, 6*SZREG(a0)
93   REG_L s4, 7*SZREG(a0)
94   REG_L s5, 8*SZREG(a0)
95   REG_L s6, 9*SZREG(a0)
96   REG_L s7, 10*SZREG(a0)
97   REG_L s8, 11*SZREG(a0)
98
99   jr ra		/* return, to where setjmp was called from */
100    move v0, a1		/* set return value */
101END(longjmp)
102
103#ifdef __ELF__
104.section .note.GNU-stack,"",%progbits
105#endif
106