1 /* Assembler macros for PA-RISC. 2 Copyright (C) 1999-2018 Free Software Foundation, Inc. 3 Contributed by Ulrich Drepper, <drepper@cygnus.com>, August 1999. 4 Linux/PA-RISC changes by Philipp Rumpf, <prumpf@tux.org>, March 2000. 5 6 The GNU C Library is free software; you can redistribute it and/or 7 modify it under the terms of the GNU Lesser General Public 8 License as published by the Free Software Foundation; either 9 version 2.1 of the License, or (at your option) any later version. 10 11 The GNU C Library is distributed in the hope that it will be useful, 12 but WITHOUT ANY WARRANTY; without even the implied warranty of 13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 Lesser General Public License for more details. 15 16 You should have received a copy of the GNU Lesser General Public 17 License along with the GNU C Library. If not, see 18 <http://www.gnu.org/licenses/>. */ 19 20 #ifndef _LINUX_HPPA_SYSDEP_H 21 #define _LINUX_HPPA_SYSDEP_H 1 22 23 #include <common/sysdep.h> 24 #include <sys/syscall.h> 25 26 /* In order to get __set_errno() definition in INLINE_SYSCALL. */ 27 #ifndef __ASSEMBLER__ 28 #include <errno.h> 29 #endif 30 31 #undef ASM_LINE_SEP 32 #define ASM_LINE_SEP ! 33 34 #undef SYS_ify 35 #define SYS_ify(syscall_name) (__NR_##syscall_name) 36 37 /* The vfork, fork, and clone syscalls clobber r19 38 * and r21. We list r21 as either clobbered or as an 39 * input to a 6-argument syscall. We must save and 40 * restore r19 in both PIC and non-PIC cases. 41 */ 42 /* WARNING: TREG must be a callee saves register so 43 that it doesn't have to be restored after a call 44 to another function */ 45 #define TREG 4 46 #define SAVE_PIC(SREG) \ 47 copy %r19, SREG 48 #define LOAD_PIC(LREG) \ 49 copy LREG , %r19 50 /* Inline assembly defines */ 51 #define TREG_ASM "%r4" /* Cant clobber r3, it holds framemarker */ 52 #define SAVE_ASM_PIC " copy %%r19, %" TREG_ASM "\n" 53 #define LOAD_ASM_PIC " copy %" TREG_ASM ", %%r19\n" 54 #define CLOB_TREG TREG_ASM , 55 #define PIC_REG_DEF register unsigned long __r19 asm("r19"); 56 #define PIC_REG_USE , "r" (__r19) 57 58 #ifdef __ASSEMBLER__ 59 60 /* Syntactic details of assembler. */ 61 62 #define ALIGNARG(log2) log2 63 64 /* For Linux we can use the system call table in the header file 65 /usr/include/asm/unistd.h 66 of the kernel. But these symbols do not follow the SYS_* syntax 67 so we have to redefine the `SYS_ify' macro here. */ 68 #undef SYS_ify 69 #define SYS_ify(syscall_name) __NR_##syscall_name 70 71 /* ELF-like local names start with `.L'. */ 72 #undef L 73 #define L(name) .L##name 74 75 /* Linux uses a negative return value to indicate syscall errors, 76 unlike most Unices, which use the condition codes' carry flag. 77 78 Since version 2.1 the return value of a system call might be 79 negative even if the call succeeded. E.g., the `lseek' system call 80 might return a large offset. Therefore we must not anymore test 81 for < 0, but test for a real error by making sure the value in %eax 82 is a real error number. Linus said he will make sure the no syscall 83 returns a value in -1 .. -4095 as a valid result so we can safely 84 test with -4095. */ 85 86 /* We don't want the label for the error handle to be global when we define 87 it here. */ 88 /*#ifdef PIC 89 # define SYSCALL_ERROR_LABEL 0f 90 #else 91 # define SYSCALL_ERROR_LABEL syscall_error 92 #endif*/ 93 94 /* Argument manipulation from the stack for preparing to 95 make a syscall */ 96 97 #define DOARGS_0 /* nothing */ 98 #define DOARGS_1 /* nothing */ 99 #define DOARGS_2 /* nothing */ 100 #define DOARGS_3 /* nothing */ 101 #define DOARGS_4 /* nothing */ 102 #define DOARGS_5 ldw -52(%sp), %r22 ASM_LINE_SEP 103 #define DOARGS_6 DOARGS_5 ldw -56(%sp), %r21 ASM_LINE_SEP 104 105 #define UNDOARGS_0 /* nothing */ 106 #define UNDOARGS_1 /* nothing */ 107 #define UNDOARGS_2 /* nothing */ 108 #define UNDOARGS_3 /* nothing */ 109 #define UNDOARGS_4 /* nothing */ 110 #define UNDOARGS_5 /* nothing */ 111 #define UNDOARGS_6 /* nothing */ 112 113 /* Define an entry point visible from C. 114 115 There is currently a bug in gdb which prevents us from specifying 116 incomplete stabs information. Fake some entries here which specify 117 the current source file. */ 118 #undef ENTRY 119 #define ENTRY(name) \ 120 .text ASM_LINE_SEP \ 121 .align ALIGNARG(4) ASM_LINE_SEP \ 122 .export C_SYMBOL_NAME(name) ASM_LINE_SEP \ 123 .type C_SYMBOL_NAME(name),@function ASM_LINE_SEP \ 124 cfi_startproc ASM_LINE_SEP \ 125 C_LABEL(name) ASM_LINE_SEP \ 126 .PROC ASM_LINE_SEP \ 127 .CALLINFO FRAME=64,CALLS,SAVE_RP,ENTRY_GR=3 ASM_LINE_SEP \ 128 .ENTRY ASM_LINE_SEP \ 129 /* SAVE_RP says we do */ ASM_LINE_SEP \ 130 stw %rp, -20(%sr0,%sp) ASM_LINE_SEP \ 131 .cfi_offset 2, -20 ASM_LINE_SEP \ 132 /*FIXME: Call mcount? (carefull with stack!) */ 133 134 /* Some syscall wrappers do not call other functions, and 135 hence are classified as leaf, so add NO_CALLS for gdb */ 136 #define ENTRY_LEAF(name) \ 137 .text ASM_LINE_SEP \ 138 .align ALIGNARG(4) ASM_LINE_SEP \ 139 .export C_SYMBOL_NAME(name) ASM_LINE_SEP \ 140 .type C_SYMBOL_NAME(name),@function ASM_LINE_SEP \ 141 cfi_startproc ASM_LINE_SEP \ 142 C_LABEL(name) ASM_LINE_SEP \ 143 .PROC ASM_LINE_SEP \ 144 .CALLINFO FRAME=64,NO_CALLS,SAVE_RP,ENTRY_GR=3 ASM_LINE_SEP \ 145 .ENTRY ASM_LINE_SEP \ 146 /* SAVE_RP says we do */ ASM_LINE_SEP \ 147 stw %rp, -20(%sr0,%sp) ASM_LINE_SEP \ 148 .cfi_offset 2, -20 ASM_LINE_SEP \ 149 /*FIXME: Call mcount? (carefull with stack!) */ 150 151 #undef END 152 #define END(name) \ 153 .EXIT ASM_LINE_SEP \ 154 .PROCEND ASM_LINE_SEP \ 155 cfi_endproc ASM_LINE_SEP \ 156 .size C_SYMBOL_NAME(name), .-C_SYMBOL_NAME(name) ASM_LINE_SEP 157 158 /* If compiled for profiling, call `mcount' at the start 159 of each function. No, don't bother. gcc will put the 160 call in for us. */ 161 #define CALL_MCOUNT /* Do nothing. */ 162 163 /* syscall wrappers consist of 164 #include <sysdep.h> 165 PSEUDO(...) 166 ret 167 PSEUDO_END(...) 168 169 which means 170 ENTRY(name) 171 DO_CALL(...) 172 bv,n 0(2) 173 */ 174 175 #undef PSEUDO 176 #define PSEUDO(name, syscall_name, args) \ 177 ENTRY (name) ASM_LINE_SEP \ 178 /* If necc. load args from stack */ ASM_LINE_SEP \ 179 DOARGS_##args ASM_LINE_SEP \ 180 DO_CALL (syscall_name, args) ASM_LINE_SEP \ 181 UNDOARGS_##args ASM_LINE_SEP 182 183 #define ret \ 184 /* Return value set by ERRNO code */ ASM_LINE_SEP \ 185 bv,n 0(2) ASM_LINE_SEP 186 187 #undef PSEUDO_END 188 #define PSEUDO_END(name) \ 189 END (name) 190 191 /* We don't set the errno on the return from the syscall */ 192 #define PSEUDO_NOERRNO(name, syscall_name, args) \ 193 ENTRY_LEAF (name) ASM_LINE_SEP \ 194 DOARGS_##args ASM_LINE_SEP \ 195 DO_CALL_NOERRNO (syscall_name, args) ASM_LINE_SEP \ 196 UNDOARGS_##args ASM_LINE_SEP 197 198 #define ret_NOERRNO ret 199 200 #undef PSEUDO_END_NOERRNO 201 #define PSEUDO_END_NOERRNO(name) \ 202 END (name) 203 204 /* This has to return the error value */ 205 #undef PSEUDO_ERRVAL 206 #define PSEUDO_ERRVAL(name, syscall_name, args) \ 207 ENTRY_LEAF (name) ASM_LINE_SEP \ 208 DOARGS_##args ASM_LINE_SEP \ 209 DO_CALL_ERRVAL (syscall_name, args) ASM_LINE_SEP \ 210 UNDOARGS_##args ASM_LINE_SEP 211 212 #define ret_ERRVAL ret 213 214 #undef PSEUDO_END_ERRVAL 215 #define PSEUDO_END_ERRVAL(name) \ 216 END(name) 217 218 #undef JUMPTARGET 219 #define JUMPTARGET(name) name 220 #define SYSCALL_PIC_SETUP /* Nothing. */ 221 222 223 /* FIXME: This comment is not true. 224 * All the syscall assembly macros rely on finding the appropriate 225 SYSCALL_ERROR_LABEL or rather HANDLER. */ 226 227 /* int * __errno_location(void) so you have to store your value 228 into the return address! */ 229 #define DEFAULT_SYSCALL_ERROR_HANDLER \ 230 .import __errno_location,code ASM_LINE_SEP \ 231 /* branch to errno handler */ ASM_LINE_SEP \ 232 bl __errno_location,%rp ASM_LINE_SEP 233 234 /* Here are the myriad of configuration options that the above can 235 work for... what we've done is provide the framework for future 236 changes if required to each section */ 237 238 #ifdef __PIC__ 239 # if defined _LIBC_REENTRANT 240 # define SYSCALL_ERROR_HANDLER DEFAULT_SYSCALL_ERROR_HANDLER 241 # else /* !_LIBC_REENTRANT */ 242 # define SYSCALL_ERROR_HANDLER DEFAULT_SYSCALL_ERROR_HANDLER 243 # endif /* _LIBC_REENTRANT */ 244 #else 245 # ifndef _LIBC_REENTRANT 246 # define SYSCALL_ERROR_HANDLER DEFAULT_SYSCALL_ERROR_HANDLER 247 # else 248 # define SYSCALL_ERROR_HANDLER DEFAULT_SYSCALL_ERROR_HANDLER 249 # endif 250 #endif 251 252 253 /* Linux takes system call arguments in registers: 254 syscall number gr20 255 arg 1 gr26 256 arg 2 gr25 257 arg 3 gr24 258 arg 4 gr23 259 arg 5 gr22 260 arg 6 gr21 261 262 The compiler calls us by the C convention: 263 syscall number in the DO_CALL macro 264 arg 1 gr26 265 arg 2 gr25 266 arg 3 gr24 267 arg 4 gr23 268 arg 5 -52(sp) 269 arg 6 -56(sp) 270 271 gr22 and gr21 are caller-saves, so we can just load the arguments 272 there and generally be happy. */ 273 274 /* the cmpb...no_error code below inside DO_CALL 275 * is intended to mimic the if (__sys_res...) 276 * code inside INLINE_SYSCALL 277 */ 278 #define NO_ERROR -0x1000 279 280 #undef DO_CALL 281 #define DO_CALL(syscall_name, args) \ 282 /* Create a frame */ ASM_LINE_SEP \ 283 stwm TREG, 64(%sp) ASM_LINE_SEP \ 284 .cfi_def_cfa_offset -64 ASM_LINE_SEP \ 285 .cfi_offset TREG, 0 ASM_LINE_SEP \ 286 stw %sp, -4(%sp) ASM_LINE_SEP \ 287 stw %r19, -32(%sp) ASM_LINE_SEP \ 288 .cfi_offset 19, 32 ASM_LINE_SEP \ 289 /* Save r19 */ ASM_LINE_SEP \ 290 SAVE_PIC(TREG) ASM_LINE_SEP \ 291 /* Do syscall, delay loads # */ ASM_LINE_SEP \ 292 ble 0x100(%sr2,%r0) ASM_LINE_SEP \ 293 ldi SYS_ify (syscall_name), %r20 ASM_LINE_SEP \ 294 ldi NO_ERROR,%r1 ASM_LINE_SEP \ 295 cmpb,>>=,n %r1,%ret0,L(pre_end) ASM_LINE_SEP \ 296 /* Restore r19 from TREG */ ASM_LINE_SEP \ 297 LOAD_PIC(TREG) /* delay */ ASM_LINE_SEP \ 298 SYSCALL_ERROR_HANDLER ASM_LINE_SEP \ 299 /* Use TREG for temp storage */ ASM_LINE_SEP \ 300 copy %ret0, TREG /* delay */ ASM_LINE_SEP \ 301 /* OPTIMIZE: Don't reload r19 */ ASM_LINE_SEP \ 302 /* do a -1*syscall_ret0 */ ASM_LINE_SEP \ 303 sub %r0, TREG, TREG ASM_LINE_SEP \ 304 /* Store into errno location */ ASM_LINE_SEP \ 305 stw TREG, 0(%sr0,%ret0) ASM_LINE_SEP \ 306 /* return -1 as error */ ASM_LINE_SEP \ 307 ldo -1(%r0), %ret0 ASM_LINE_SEP \ 308 L(pre_end): ASM_LINE_SEP \ 309 /* Restore our frame, restoring TREG */ ASM_LINE_SEP \ 310 ldwm -64(%sp), TREG ASM_LINE_SEP \ 311 /* Restore return pointer */ ASM_LINE_SEP \ 312 ldw -20(%sp),%rp ASM_LINE_SEP 313 314 /* We do nothing with the return, except hand it back to someone else */ 315 #undef DO_CALL_NOERRNO 316 #define DO_CALL_NOERRNO(syscall_name, args) \ 317 /* No need to store r19 */ ASM_LINE_SEP \ 318 ble 0x100(%sr2,%r0) ASM_LINE_SEP \ 319 ldi SYS_ify (syscall_name), %r20 ASM_LINE_SEP \ 320 /* Caller will restore r19 */ ASM_LINE_SEP 321 322 /* Here, we return the ERRVAL in assembly, note we don't call the 323 error handler function, but we do 'negate' the return _IF_ 324 it's an error. Not sure if this is the right semantic. */ 325 326 #undef DO_CALL_ERRVAL 327 #define DO_CALL_ERRVAL(syscall_name, args) \ 328 /* No need to store r19 */ ASM_LINE_SEP \ 329 ble 0x100(%sr2,%r0) ASM_LINE_SEP \ 330 ldi SYS_ify (syscall_name), %r20 ASM_LINE_SEP \ 331 /* Caller will restore r19 */ ASM_LINE_SEP \ 332 ldi NO_ERROR,%r1 ASM_LINE_SEP \ 333 cmpb,>>=,n %r1,%ret0,0f ASM_LINE_SEP \ 334 sub %r0, %ret0, %ret0 ASM_LINE_SEP \ 335 0: ASM_LINE_SEP 336 337 338 #else 339 340 /* GCC has to be warned that a syscall may clobber all the ABI 341 registers listed as "caller-saves", see page 8, Table 2 342 in section 2.2.6 of the PA-RISC RUN-TIME architecture 343 document. However! r28 is the result and will conflict with 344 the clobber list so it is left out. Also the input arguments 345 registers r20 -> r26 will conflict with the list so they 346 are treated specially. Although r19 is clobbered by the syscall 347 we cannot say this because it would violate ABI, thus we say 348 TREG is clobbered and use that register to save/restore r19 349 across the syscall. */ 350 351 #define CALL_CLOB_REGS "%r1", "%r2", CLOB_TREG \ 352 "%r20", "%r29", "%r31" 353 354 #endif /* __ASSEMBLER__ */ 355 356 #endif /* _LINUX_HPPA_SYSDEP_H */ 357