1 /* 2 * PARISC Architecture-dependent parts of process handling 3 * based on the work for i386 4 * 5 * Copyright (C) 1999-2003 Matthew Wilcox <willy at parisc-linux.org> 6 * Copyright (C) 2000 Martin K Petersen <mkp at mkp.net> 7 * Copyright (C) 2000 John Marvin <jsm at parisc-linux.org> 8 * Copyright (C) 2000 David Huggins-Daines <dhd with pobox.org> 9 * Copyright (C) 2000-2003 Paul Bame <bame at parisc-linux.org> 10 * Copyright (C) 2000 Philipp Rumpf <prumpf with tux.org> 11 * Copyright (C) 2000 David Kennedy <dkennedy with linuxcare.com> 12 * Copyright (C) 2000 Richard Hirst <rhirst with parisc-linux.org> 13 * Copyright (C) 2000 Grant Grundler <grundler with parisc-linux.org> 14 * Copyright (C) 2001 Alan Modra <amodra at parisc-linux.org> 15 * Copyright (C) 2001-2002 Ryan Bradetich <rbrad at parisc-linux.org> 16 * Copyright (C) 2001-2002 Helge Deller <deller at parisc-linux.org> 17 * Copyright (C) 2002 Randolph Chung <tausq with parisc-linux.org> 18 * 19 * 20 * This program is free software; you can redistribute it and/or modify 21 * it under the terms of the GNU General Public License as published by 22 * the Free Software Foundation; either version 2 of the License, or 23 * (at your option) any later version. 24 * 25 * This program is distributed in the hope that it will be useful, 26 * but WITHOUT ANY WARRANTY; without even the implied warranty of 27 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 28 * GNU General Public License for more details. 29 * 30 * You should have received a copy of the GNU General Public License 31 * along with this program; if not, write to the Free Software 32 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA 33 */ 34 35 #include <stdarg.h> 36 37 #include <linux/elf.h> 38 #include <linux/errno.h> 39 #include <linux/kernel.h> 40 #include <linux/mm.h> 41 #include <linux/module.h> 42 #include <linux/personality.h> 43 #include <linux/ptrace.h> 44 #include <linux/sched.h> 45 #include <linux/stddef.h> 46 #include <linux/unistd.h> 47 #include <linux/kallsyms.h> 48 49 #include <asm/io.h> 50 #include <asm/asm-offsets.h> 51 #include <asm/pdc.h> 52 #include <asm/pdc_chassis.h> 53 #include <asm/pgalloc.h> 54 #include <asm/uaccess.h> 55 #include <asm/unwind.h> 56 57 static int hlt_counter; 58 59 /* 60 * Power off function, if any 61 */ 62 void (*pm_power_off)(void); 63 64 void disable_hlt(void) 65 { 66 hlt_counter++; 67 } 68 69 EXPORT_SYMBOL(disable_hlt); 70 71 void enable_hlt(void) 72 { 73 hlt_counter--; 74 } 75 76 EXPORT_SYMBOL(enable_hlt); 77 78 void default_idle(void) 79 { 80 barrier(); 81 } 82 83 /* 84 * The idle thread. There's no useful work to be 85 * done, so just try to conserve power and have a 86 * low exit latency (ie sit in a loop waiting for 87 * somebody to say that they'd like to reschedule) 88 */ 89 void cpu_idle(void) 90 { 91 /* endless idle loop with no priority at all */ 92 while (1) { 93 while (!need_resched()) 94 barrier(); 95 schedule(); 96 check_pgt_cache(); 97 } 98 } 99 100 101 #ifdef __LP64__ 102 #define COMMAND_GLOBAL 0xfffffffffffe0030UL 103 #else 104 #define COMMAND_GLOBAL 0xfffe0030 105 #endif 106 107 #define CMD_RESET 5 /* reset any module */ 108 109 /* 110 ** The Wright Brothers and Gecko systems have a H/W problem 111 ** (Lasi...'nuf said) may cause a broadcast reset to lockup 112 ** the system. An HVERSION dependent PDC call was developed 113 ** to perform a "safe", platform specific broadcast reset instead 114 ** of kludging up all the code. 115 ** 116 ** Older machines which do not implement PDC_BROADCAST_RESET will 117 ** return (with an error) and the regular broadcast reset can be 118 ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET 119 ** the PDC call will not return (the system will be reset). 120 */ 121 void machine_restart(char *cmd) 122 { 123 #ifdef FASTBOOT_SELFTEST_SUPPORT 124 /* 125 ** If user has modified the Firmware Selftest Bitmap, 126 ** run the tests specified in the bitmap after the 127 ** system is rebooted w/PDC_DO_RESET. 128 ** 129 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests" 130 ** 131 ** Using "directed resets" at each processor with the MEM_TOC 132 ** vector cleared will also avoid running destructive 133 ** memory self tests. (Not implemented yet) 134 */ 135 if (ftc_bitmap) { 136 pdc_do_firm_test_reset(ftc_bitmap); 137 } 138 #endif 139 /* set up a new led state on systems shipped with a LED State panel */ 140 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 141 142 /* "Normal" system reset */ 143 pdc_do_reset(); 144 145 /* Nope...box should reset with just CMD_RESET now */ 146 gsc_writel(CMD_RESET, COMMAND_GLOBAL); 147 148 /* Wait for RESET to lay us to rest. */ 149 while (1) ; 150 151 } 152 153 void machine_halt(void) 154 { 155 /* 156 ** The LED/ChassisCodes are updated by the led_halt() 157 ** function, called by the reboot notifier chain. 158 */ 159 } 160 161 162 /* 163 * This routine is called from sys_reboot to actually turn off the 164 * machine 165 */ 166 void machine_power_off(void) 167 { 168 /* If there is a registered power off handler, call it. */ 169 if(pm_power_off) 170 pm_power_off(); 171 172 /* Put the soft power button back under hardware control. 173 * If the user had already pressed the power button, the 174 * following call will immediately power off. */ 175 pdc_soft_power_button(0); 176 177 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 178 179 /* It seems we have no way to power the system off via 180 * software. The user has to press the button himself. */ 181 182 printk(KERN_EMERG "System shut down completed.\n" 183 KERN_EMERG "Please power this system off now."); 184 } 185 186 187 /* 188 * Create a kernel thread 189 */ 190 191 extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); 192 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 193 { 194 195 /* 196 * FIXME: Once we are sure we don't need any debug here, 197 * kernel_thread can become a #define. 198 */ 199 200 return __kernel_thread(fn, arg, flags); 201 } 202 EXPORT_SYMBOL(kernel_thread); 203 204 /* 205 * Free current thread data structures etc.. 206 */ 207 void exit_thread(void) 208 { 209 } 210 211 void flush_thread(void) 212 { 213 /* Only needs to handle fpu stuff or perf monitors. 214 ** REVISIT: several arches implement a "lazy fpu state". 215 */ 216 set_fs(USER_DS); 217 } 218 219 void release_thread(struct task_struct *dead_task) 220 { 221 } 222 223 /* 224 * Fill in the FPU structure for a core dump. 225 */ 226 227 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r) 228 { 229 if (regs == NULL) 230 return 0; 231 232 memcpy(r, regs->fr, sizeof *r); 233 return 1; 234 } 235 236 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r) 237 { 238 memcpy(r, tsk->thread.regs.fr, sizeof(*r)); 239 return 1; 240 } 241 242 /* Note that "fork()" is implemented in terms of clone, with 243 parameters (SIGCHLD, regs->gr[30], regs). */ 244 int 245 sys_clone(unsigned long clone_flags, unsigned long usp, 246 struct pt_regs *regs) 247 { 248 /* Arugments from userspace are: 249 r26 = Clone flags. 250 r25 = Child stack. 251 r24 = parent_tidptr. 252 r23 = Is the TLS storage descriptor 253 r22 = child_tidptr 254 255 However, these last 3 args are only examined 256 if the proper flags are set. */ 257 int __user *child_tidptr; 258 int __user *parent_tidptr; 259 260 /* usp must be word aligned. This also prevents users from 261 * passing in the value 1 (which is the signal for a special 262 * return for a kernel thread) */ 263 usp = ALIGN(usp, 4); 264 265 /* A zero value for usp means use the current stack */ 266 if (usp == 0) 267 usp = regs->gr[30]; 268 269 if (clone_flags & CLONE_PARENT_SETTID) 270 parent_tidptr = (int __user *)regs->gr[24]; 271 else 272 parent_tidptr = NULL; 273 274 if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) 275 child_tidptr = (int __user *)regs->gr[22]; 276 else 277 child_tidptr = NULL; 278 279 return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr); 280 } 281 282 int 283 sys_vfork(struct pt_regs *regs) 284 { 285 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL); 286 } 287 288 int 289 copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 290 unsigned long unused, /* in ia64 this is "user_stack_size" */ 291 struct task_struct * p, struct pt_regs * pregs) 292 { 293 struct pt_regs * cregs = &(p->thread.regs); 294 struct thread_info *ti = p->thread_info; 295 296 /* We have to use void * instead of a function pointer, because 297 * function pointers aren't a pointer to the function on 64-bit. 298 * Make them const so the compiler knows they live in .text */ 299 extern void * const ret_from_kernel_thread; 300 extern void * const child_return; 301 #ifdef CONFIG_HPUX 302 extern void * const hpux_child_return; 303 #endif 304 305 *cregs = *pregs; 306 307 /* Set the return value for the child. Note that this is not 308 actually restored by the syscall exit path, but we put it 309 here for consistency in case of signals. */ 310 cregs->gr[28] = 0; /* child */ 311 312 /* 313 * We need to differentiate between a user fork and a 314 * kernel fork. We can't use user_mode, because the 315 * the syscall path doesn't save iaoq. Right now 316 * We rely on the fact that kernel_thread passes 317 * in zero for usp. 318 */ 319 if (usp == 1) { 320 /* kernel thread */ 321 cregs->ksp = (((unsigned long)(ti)) + THREAD_SZ_ALGN); 322 /* Must exit via ret_from_kernel_thread in order 323 * to call schedule_tail() 324 */ 325 cregs->kpc = (unsigned long) &ret_from_kernel_thread; 326 /* 327 * Copy function and argument to be called from 328 * ret_from_kernel_thread. 329 */ 330 #ifdef __LP64__ 331 cregs->gr[27] = pregs->gr[27]; 332 #endif 333 cregs->gr[26] = pregs->gr[26]; 334 cregs->gr[25] = pregs->gr[25]; 335 } else { 336 /* user thread */ 337 /* 338 * Note that the fork wrappers are responsible 339 * for setting gr[21]. 340 */ 341 342 /* Use same stack depth as parent */ 343 cregs->ksp = ((unsigned long)(ti)) 344 + (pregs->gr[21] & (THREAD_SIZE - 1)); 345 cregs->gr[30] = usp; 346 if (p->personality == PER_HPUX) { 347 #ifdef CONFIG_HPUX 348 cregs->kpc = (unsigned long) &hpux_child_return; 349 #else 350 BUG(); 351 #endif 352 } else { 353 cregs->kpc = (unsigned long) &child_return; 354 } 355 /* Setup thread TLS area from the 4th parameter in clone */ 356 if (clone_flags & CLONE_SETTLS) 357 cregs->cr27 = pregs->gr[23]; 358 359 } 360 361 return 0; 362 } 363 364 unsigned long thread_saved_pc(struct task_struct *t) 365 { 366 return t->thread.regs.kpc; 367 } 368 369 /* 370 * sys_execve() executes a new program. 371 */ 372 373 asmlinkage int sys_execve(struct pt_regs *regs) 374 { 375 int error; 376 char *filename; 377 378 filename = getname((const char __user *) regs->gr[26]); 379 error = PTR_ERR(filename); 380 if (IS_ERR(filename)) 381 goto out; 382 error = do_execve(filename, (char __user **) regs->gr[25], 383 (char __user **) regs->gr[24], regs); 384 if (error == 0) { 385 task_lock(current); 386 current->ptrace &= ~PT_DTRACE; 387 task_unlock(current); 388 } 389 putname(filename); 390 out: 391 392 return error; 393 } 394 395 unsigned long 396 get_wchan(struct task_struct *p) 397 { 398 struct unwind_frame_info info; 399 unsigned long ip; 400 int count = 0; 401 /* 402 * These bracket the sleeping functions.. 403 */ 404 405 unwind_frame_init_from_blocked_task(&info, p); 406 do { 407 if (unwind_once(&info) < 0) 408 return 0; 409 ip = info.ip; 410 if (!in_sched_functions(ip)) 411 return ip; 412 } while (count++ < 16); 413 return 0; 414 } 415