1 /* Assembler macros for Nios II.
2    Copyright (C) 2000-2021 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4 
5    The GNU C Library is free software; you can redistribute it and/or
6    modify it under the terms of the GNU Lesser General Public
7    License as published by the Free Software Foundation; either
8    version 2.1 of the License, or (at your option) any later version.
9 
10    The GNU C Library is distributed in the hope that it will be useful,
11    but WITHOUT ANY WARRANTY; without even the implied warranty of
12    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13    Lesser General Public License for more details.
14 
15    You should have received a copy of the GNU Lesser General Public
16    License along with the GNU C Library; if not, see
17    <https://www.gnu.org/licenses/>.  */
18 
19 #ifndef _LINUX_NIOS2_SYSDEP_H
20 #define _LINUX_NIOS2_SYSDEP_H 1
21 
22 #include <sysdeps/unix/sysdep.h>
23 #include <sysdeps/nios2/sysdep.h>
24 #include <sysdeps/unix/sysv/linux/generic/sysdep.h>
25 
26 /* For RTLD_PRIVATE_ERRNO.  */
27 #include <dl-sysdep.h>
28 
29 #include <tls.h>
30 
31 /* For Linux we can use the system call table in the header file
32         /usr/include/asm/unistd.h
33    of the kernel.  But these symbols do not follow the SYS_* syntax
34    so we have to redefine the `SYS_ify' macro here.  */
35 #undef SYS_ify
36 #define SYS_ify(syscall_name)   __NR_##syscall_name
37 
38 #ifdef __ASSEMBLER__
39 
40 #undef SYSCALL_ERROR_LABEL
41 #define SYSCALL_ERROR_LABEL __local_syscall_error
42 
43 #undef PSEUDO
44 #define PSEUDO(name, syscall_name, args) \
45   ENTRY (name)                           \
46     DO_CALL (syscall_name, args)         \
47     bne r7, zero, SYSCALL_ERROR_LABEL;   \
48 
49 #undef PSEUDO_END
50 #define PSEUDO_END(name) \
51   SYSCALL_ERROR_HANDLER  \
52   END (name)
53 
54 #undef PSEUDO_NOERRNO
55 #define PSEUDO_NOERRNO(name, syscall_name, args) \
56   ENTRY (name)                                   \
57     DO_CALL (syscall_name, args)
58 
59 #undef PSEUDO_END_NOERRNO
60 #define PSEUDO_END_NOERRNO(name) \
61   END (name)
62 
63 #undef ret_NOERRNO
64 #define ret_NOERRNO ret
65 
66 #undef DO_CALL
67 #define DO_CALL(syscall_name, args) \
68     DOARGS_##args                   \
69     movi r2, SYS_ify(syscall_name);  \
70     trap;
71 
72 #if defined(__PIC__) || defined(PIC)
73 
74 # if RTLD_PRIVATE_ERRNO
75 
76 #  define SYSCALL_ERROR_HANDLER			\
77   SYSCALL_ERROR_LABEL:				\
78   nextpc r3;					\
79 1:						\
80   movhi r8, %hiadj(rtld_errno - 1b);		\
81   addi r8, r8, %lo(rtld_errno - 1b);		\
82   add r3, r3, r8;				\
83   stw r2, 0(r3);				\
84   movi r2, -1;					\
85   ret;
86 
87 # else
88 
89 #  if IS_IN (libc)
90 #   define SYSCALL_ERROR_ERRNO __libc_errno
91 #  else
92 #   define SYSCALL_ERROR_ERRNO errno
93 #  endif
94 #  define SYSCALL_ERROR_HANDLER			\
95   SYSCALL_ERROR_LABEL:				\
96   nextpc r3;					\
97 1:						\
98   movhi r8, %hiadj(_gp_got - 1b);		\
99   addi r8, r8, %lo(_gp_got - 1b);		\
100   add r3, r3, r8;				\
101   ldw r3, %tls_ie(SYSCALL_ERROR_ERRNO)(r3);	\
102   add r3, r23, r3;				\
103   stw r2, 0(r3);				\
104   movi r2, -1;					\
105   ret;
106 
107 # endif
108 
109 #else
110 
111 /* We can use a single error handler in the static library.  */
112 #define SYSCALL_ERROR_HANDLER			\
113   SYSCALL_ERROR_LABEL:				\
114   jmpi __syscall_error;
115 
116 #endif
117 
118 #define DOARGS_0 /* nothing */
119 #define DOARGS_1 /* nothing */
120 #define DOARGS_2 /* nothing */
121 #define DOARGS_3 /* nothing */
122 #define DOARGS_4 /* nothing */
123 #define DOARGS_5 ldw r8, 0(sp);
124 #define DOARGS_6 ldw r9, 4(sp); ldw r8, 0(sp);
125 
126 /* The function has to return the error code.  */
127 #undef  PSEUDO_ERRVAL
128 #define PSEUDO_ERRVAL(name, syscall_name, args) \
129   ENTRY (name)                                  \
130     DO_CALL (syscall_name, args)
131 
132 #undef  PSEUDO_END_ERRVAL
133 #define PSEUDO_END_ERRVAL(name) \
134   END (name)
135 
136 #define ret_ERRVAL ret
137 
138 #else /* __ASSEMBLER__ */
139 
140 /* In order to get __set_errno() definition in INLINE_SYSCALL.  */
141 #include <errno.h>
142 
143 #undef INTERNAL_SYSCALL_RAW
144 #define INTERNAL_SYSCALL_RAW(name, nr, args...)                 \
145   ({ unsigned int _sys_result;                                  \
146      {                                                          \
147        /* Load argument values in temporary variables
148 	  to perform side effects like function calls
149 	  before the call-used registers are set.  */		\
150        LOAD_ARGS_##nr (args)					\
151        LOAD_REGS_##nr						\
152        register int _r2 asm ("r2") = (int)(name);               \
153        register int _err asm ("r7");                            \
154        asm volatile ("trap"                                     \
155                      : "+r" (_r2), "=r" (_err)                  \
156                      : ASM_ARGS_##nr				\
157                      : __SYSCALL_CLOBBERS);                     \
158        _sys_result = _err != 0 ? -_r2 : _r2;                    \
159      }                                                          \
160      (int) _sys_result; })
161 
162 #undef INTERNAL_SYSCALL
163 #define INTERNAL_SYSCALL(name, nr, args...) \
164 	INTERNAL_SYSCALL_RAW(SYS_ify(name), nr, args)
165 
166 #undef INTERNAL_SYSCALL_NCS
167 #define INTERNAL_SYSCALL_NCS(number, nr, args...) \
168 	INTERNAL_SYSCALL_RAW(number, nr, args)
169 
170 #define LOAD_ARGS_0()
171 #define LOAD_REGS_0
172 #define ASM_ARGS_0
173 #define LOAD_ARGS_1(a1)				\
174   LOAD_ARGS_0 ()				\
175   int __arg1 = (int) (a1);
176 #define LOAD_REGS_1				\
177   register int _r4 asm ("r4") = __arg1;		\
178   LOAD_REGS_0
179 #define ASM_ARGS_1                  "r" (_r4)
180 #define LOAD_ARGS_2(a1, a2)			\
181   LOAD_ARGS_1 (a1)				\
182   int __arg2 = (int) (a2);
183 #define LOAD_REGS_2				\
184   register int _r5 asm ("r5") = __arg2;		\
185   LOAD_REGS_1
186 #define ASM_ARGS_2      ASM_ARGS_1, "r" (_r5)
187 #define LOAD_ARGS_3(a1, a2, a3)			\
188   LOAD_ARGS_2 (a1, a2)				\
189   int __arg3 = (int) (a3);
190 #define LOAD_REGS_3				\
191   register int _r6 asm ("r6") = __arg3;		\
192   LOAD_REGS_2
193 #define ASM_ARGS_3      ASM_ARGS_2, "r" (_r6)
194 #define LOAD_ARGS_4(a1, a2, a3, a4)		\
195   LOAD_ARGS_3 (a1, a2, a3)			\
196   int __arg4 = (int) (a4);
197 #define LOAD_REGS_4				\
198   register int _r7 asm ("r7") = __arg4;		\
199   LOAD_REGS_3
200 #define ASM_ARGS_4      ASM_ARGS_3, "r" (_r7)
201 #define LOAD_ARGS_5(a1, a2, a3, a4, a5)		\
202   LOAD_ARGS_4 (a1, a2, a3, a4)			\
203   int __arg5 = (int) (a5);
204 #define LOAD_REGS_5				\
205   register int _r8 asm ("r8") = __arg5;		\
206   LOAD_REGS_4
207 #define ASM_ARGS_5      ASM_ARGS_4, "r" (_r8)
208 #define LOAD_ARGS_6(a1, a2, a3, a4, a5, a6)	\
209   LOAD_ARGS_5 (a1, a2, a3, a4, a5)		\
210   int __arg6 = (int) (a6);
211 #define LOAD_REGS_6			    \
212   register int _r9 asm ("r9") = __arg6;     \
213   LOAD_REGS_5
214 #define ASM_ARGS_6      ASM_ARGS_5, "r" (_r9)
215 
216 #define __SYSCALL_CLOBBERS "memory"
217 
218 #undef HAVE_INTERNAL_BRK_ADDR_SYMBOL
219 #define HAVE_INTERNAL_BRK_ADDR_SYMBOL 1
220 
221 #endif /* __ASSEMBLER__ */
222 
223 /* Pointer mangling support.  */
224 #if IS_IN (rtld)
225 /* We cannot use the thread descriptor because in ld.so we use setjmp
226    earlier than the descriptor is initialized.  */
227 #else
228 # ifdef __ASSEMBLER__
229 #  define PTR_MANGLE_GUARD(guard) ldw guard, POINTER_GUARD(r23)
230 #  define PTR_MANGLE(dst, src, guard) xor dst, src, guard
231 #  define PTR_DEMANGLE(dst, src, guard) PTR_MANGLE (dst, src, guard)
232 # else
233 #  define PTR_MANGLE(var) \
234   (var) = (__typeof (var)) ((uintptr_t) (var) ^ THREAD_GET_POINTER_GUARD ())
235 #  define PTR_DEMANGLE(var)	PTR_MANGLE (var)
236 # endif
237 #endif
238 
239 
240 #endif /* linux/nios2/sysdep.h */
241