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