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Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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linux
1/* SPDX-License-Identifier: LGPL-2.1 OR MIT */
2/*
3 * s390 specific definitions for NOLIBC
4 */
5
6#ifndef _NOLIBC_ARCH_S390_H
7#define _NOLIBC_ARCH_S390_H
8#include <linux/signal.h>
9#include <linux/unistd.h>
10
11#include "compiler.h"
12#include "crt.h"
13#include "std.h"
14
15/* Syscalls for s390:
16 * - registers are 64-bit
17 * - syscall number is passed in r1
18 * - arguments are in r2-r7
19 * - the system call is performed by calling the svc instruction
20 * - syscall return value is in r2
21 * - r1 and r2 are clobbered, others are preserved.
22 *
23 * Link s390 ABI: https://github.com/IBM/s390x-abi
24 *
25 */
26
27#define my_syscall0(num) \
28({ \
29 register long _num __asm__ ("1") = (num); \
30 register long _rc __asm__ ("2"); \
31 \
32 __asm__ volatile ( \
33 "svc 0\n" \
34 : "=d"(_rc) \
35 : "d"(_num) \
36 : "memory", "cc" \
37 ); \
38 _rc; \
39})
40
41#define my_syscall1(num, arg1) \
42({ \
43 register long _num __asm__ ("1") = (num); \
44 register long _arg1 __asm__ ("2") = (long)(arg1); \
45 \
46 __asm__ volatile ( \
47 "svc 0\n" \
48 : "+d"(_arg1) \
49 : "d"(_num) \
50 : "memory", "cc" \
51 ); \
52 _arg1; \
53})
54
55#define my_syscall2(num, arg1, arg2) \
56({ \
57 register long _num __asm__ ("1") = (num); \
58 register long _arg1 __asm__ ("2") = (long)(arg1); \
59 register long _arg2 __asm__ ("3") = (long)(arg2); \
60 \
61 __asm__ volatile ( \
62 "svc 0\n" \
63 : "+d"(_arg1) \
64 : "d"(_arg2), "d"(_num) \
65 : "memory", "cc" \
66 ); \
67 _arg1; \
68})
69
70#define my_syscall3(num, arg1, arg2, arg3) \
71({ \
72 register long _num __asm__ ("1") = (num); \
73 register long _arg1 __asm__ ("2") = (long)(arg1); \
74 register long _arg2 __asm__ ("3") = (long)(arg2); \
75 register long _arg3 __asm__ ("4") = (long)(arg3); \
76 \
77 __asm__ volatile ( \
78 "svc 0\n" \
79 : "+d"(_arg1) \
80 : "d"(_arg2), "d"(_arg3), "d"(_num) \
81 : "memory", "cc" \
82 ); \
83 _arg1; \
84})
85
86#define my_syscall4(num, arg1, arg2, arg3, arg4) \
87({ \
88 register long _num __asm__ ("1") = (num); \
89 register long _arg1 __asm__ ("2") = (long)(arg1); \
90 register long _arg2 __asm__ ("3") = (long)(arg2); \
91 register long _arg3 __asm__ ("4") = (long)(arg3); \
92 register long _arg4 __asm__ ("5") = (long)(arg4); \
93 \
94 __asm__ volatile ( \
95 "svc 0\n" \
96 : "+d"(_arg1) \
97 : "d"(_arg2), "d"(_arg3), "d"(_arg4), "d"(_num) \
98 : "memory", "cc" \
99 ); \
100 _arg1; \
101})
102
103#define my_syscall5(num, arg1, arg2, arg3, arg4, arg5) \
104({ \
105 register long _num __asm__ ("1") = (num); \
106 register long _arg1 __asm__ ("2") = (long)(arg1); \
107 register long _arg2 __asm__ ("3") = (long)(arg2); \
108 register long _arg3 __asm__ ("4") = (long)(arg3); \
109 register long _arg4 __asm__ ("5") = (long)(arg4); \
110 register long _arg5 __asm__ ("6") = (long)(arg5); \
111 \
112 __asm__ volatile ( \
113 "svc 0\n" \
114 : "+d"(_arg1) \
115 : "d"(_arg2), "d"(_arg3), "d"(_arg4), "d"(_arg5), \
116 "d"(_num) \
117 : "memory", "cc" \
118 ); \
119 _arg1; \
120})
121
122#define my_syscall6(num, arg1, arg2, arg3, arg4, arg5, arg6) \
123({ \
124 register long _num __asm__ ("1") = (num); \
125 register long _arg1 __asm__ ("2") = (long)(arg1); \
126 register long _arg2 __asm__ ("3") = (long)(arg2); \
127 register long _arg3 __asm__ ("4") = (long)(arg3); \
128 register long _arg4 __asm__ ("5") = (long)(arg4); \
129 register long _arg5 __asm__ ("6") = (long)(arg5); \
130 register long _arg6 __asm__ ("7") = (long)(arg6); \
131 \
132 __asm__ volatile ( \
133 "svc 0\n" \
134 : "+d"(_arg1) \
135 : "d"(_arg2), "d"(_arg3), "d"(_arg4), "d"(_arg5), \
136 "d"(_arg6), "d"(_num) \
137 : "memory", "cc" \
138 ); \
139 _arg1; \
140})
141
142/* startup code */
143void __attribute__((weak, noreturn)) __nolibc_entrypoint __no_stack_protector _start(void)
144{
145 __asm__ volatile (
146#ifdef __s390x__
147 "lgr %r2, %r15\n" /* save stack pointer to %r2, as arg1 of _start_c */
148 "aghi %r15, -160\n" /* allocate new stackframe */
149#else
150 "lr %r2, %r15\n"
151 "ahi %r15, -96\n"
152#endif
153 "xc 0(8,%r15), 0(%r15)\n" /* clear backchain */
154 "brasl %r14, _start_c\n" /* transfer to c runtime */
155 );
156 __nolibc_entrypoint_epilogue();
157}
158
159struct s390_mmap_arg_struct {
160 unsigned long addr;
161 unsigned long len;
162 unsigned long prot;
163 unsigned long flags;
164 unsigned long fd;
165 unsigned long offset;
166};
167
168static __attribute__((unused))
169void *sys_mmap(void *addr, size_t length, int prot, int flags, int fd,
170 off_t offset)
171{
172 struct s390_mmap_arg_struct args = {
173 .addr = (unsigned long)addr,
174 .len = (unsigned long)length,
175 .prot = prot,
176 .flags = flags,
177 .fd = fd,
178 .offset = (unsigned long)offset
179 };
180
181 return (void *)my_syscall1(__NR_mmap, &args);
182}
183#define sys_mmap sys_mmap
184
185static __attribute__((unused))
186pid_t sys_fork(void)
187{
188 return my_syscall5(__NR_clone, 0, SIGCHLD, 0, 0, 0);
189}
190#define sys_fork sys_fork
191
192#endif /* _NOLIBC_ARCH_S390_H */