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 set_thread_flag(TIF_POLLING_NRFLAG); 92 93 /* endless idle loop with no priority at all */ 94 while (1) { 95 while (!need_resched()) 96 barrier(); 97 preempt_enable_no_resched(); 98 schedule(); 99 preempt_disable(); 100 check_pgt_cache(); 101 } 102 } 103 104 105 #ifdef __LP64__ 106 #define COMMAND_GLOBAL 0xfffffffffffe0030UL 107 #else 108 #define COMMAND_GLOBAL 0xfffe0030 109 #endif 110 111 #define CMD_RESET 5 /* reset any module */ 112 113 /* 114 ** The Wright Brothers and Gecko systems have a H/W problem 115 ** (Lasi...'nuf said) may cause a broadcast reset to lockup 116 ** the system. An HVERSION dependent PDC call was developed 117 ** to perform a "safe", platform specific broadcast reset instead 118 ** of kludging up all the code. 119 ** 120 ** Older machines which do not implement PDC_BROADCAST_RESET will 121 ** return (with an error) and the regular broadcast reset can be 122 ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET 123 ** the PDC call will not return (the system will be reset). 124 */ 125 void machine_restart(char *cmd) 126 { 127 #ifdef FASTBOOT_SELFTEST_SUPPORT 128 /* 129 ** If user has modified the Firmware Selftest Bitmap, 130 ** run the tests specified in the bitmap after the 131 ** system is rebooted w/PDC_DO_RESET. 132 ** 133 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests" 134 ** 135 ** Using "directed resets" at each processor with the MEM_TOC 136 ** vector cleared will also avoid running destructive 137 ** memory self tests. (Not implemented yet) 138 */ 139 if (ftc_bitmap) { 140 pdc_do_firm_test_reset(ftc_bitmap); 141 } 142 #endif 143 /* set up a new led state on systems shipped with a LED State panel */ 144 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 145 146 /* "Normal" system reset */ 147 pdc_do_reset(); 148 149 /* Nope...box should reset with just CMD_RESET now */ 150 gsc_writel(CMD_RESET, COMMAND_GLOBAL); 151 152 /* Wait for RESET to lay us to rest. */ 153 while (1) ; 154 155 } 156 157 void machine_halt(void) 158 { 159 /* 160 ** The LED/ChassisCodes are updated by the led_halt() 161 ** function, called by the reboot notifier chain. 162 */ 163 } 164 165 166 /* 167 * This routine is called from sys_reboot to actually turn off the 168 * machine 169 */ 170 void machine_power_off(void) 171 { 172 /* If there is a registered power off handler, call it. */ 173 if(pm_power_off) 174 pm_power_off(); 175 176 /* Put the soft power button back under hardware control. 177 * If the user had already pressed the power button, the 178 * following call will immediately power off. */ 179 pdc_soft_power_button(0); 180 181 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 182 183 /* It seems we have no way to power the system off via 184 * software. The user has to press the button himself. */ 185 186 printk(KERN_EMERG "System shut down completed.\n" 187 KERN_EMERG "Please power this system off now."); 188 } 189 190 191 /* 192 * Create a kernel thread 193 */ 194 195 extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); 196 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 197 { 198 199 /* 200 * FIXME: Once we are sure we don't need any debug here, 201 * kernel_thread can become a #define. 202 */ 203 204 return __kernel_thread(fn, arg, flags); 205 } 206 EXPORT_SYMBOL(kernel_thread); 207 208 /* 209 * Free current thread data structures etc.. 210 */ 211 void exit_thread(void) 212 { 213 } 214 215 void flush_thread(void) 216 { 217 /* Only needs to handle fpu stuff or perf monitors. 218 ** REVISIT: several arches implement a "lazy fpu state". 219 */ 220 set_fs(USER_DS); 221 } 222 223 void release_thread(struct task_struct *dead_task) 224 { 225 } 226 227 /* 228 * Fill in the FPU structure for a core dump. 229 */ 230 231 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r) 232 { 233 if (regs == NULL) 234 return 0; 235 236 memcpy(r, regs->fr, sizeof *r); 237 return 1; 238 } 239 240 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r) 241 { 242 memcpy(r, tsk->thread.regs.fr, sizeof(*r)); 243 return 1; 244 } 245 246 /* Note that "fork()" is implemented in terms of clone, with 247 parameters (SIGCHLD, regs->gr[30], regs). */ 248 int 249 sys_clone(unsigned long clone_flags, unsigned long usp, 250 struct pt_regs *regs) 251 { 252 /* Arugments from userspace are: 253 r26 = Clone flags. 254 r25 = Child stack. 255 r24 = parent_tidptr. 256 r23 = Is the TLS storage descriptor 257 r22 = child_tidptr 258 259 However, these last 3 args are only examined 260 if the proper flags are set. */ 261 int __user *child_tidptr; 262 int __user *parent_tidptr; 263 264 /* usp must be word aligned. This also prevents users from 265 * passing in the value 1 (which is the signal for a special 266 * return for a kernel thread) */ 267 usp = ALIGN(usp, 4); 268 269 /* A zero value for usp means use the current stack */ 270 if (usp == 0) 271 usp = regs->gr[30]; 272 273 if (clone_flags & CLONE_PARENT_SETTID) 274 parent_tidptr = (int __user *)regs->gr[24]; 275 else 276 parent_tidptr = NULL; 277 278 if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) 279 child_tidptr = (int __user *)regs->gr[22]; 280 else 281 child_tidptr = NULL; 282 283 return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr); 284 } 285 286 int 287 sys_vfork(struct pt_regs *regs) 288 { 289 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL); 290 } 291 292 int 293 copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 294 unsigned long unused, /* in ia64 this is "user_stack_size" */ 295 struct task_struct * p, struct pt_regs * pregs) 296 { 297 struct pt_regs * cregs = &(p->thread.regs); 298 struct thread_info *ti = p->thread_info; 299 300 /* We have to use void * instead of a function pointer, because 301 * function pointers aren't a pointer to the function on 64-bit. 302 * Make them const so the compiler knows they live in .text */ 303 extern void * const ret_from_kernel_thread; 304 extern void * const child_return; 305 #ifdef CONFIG_HPUX 306 extern void * const hpux_child_return; 307 #endif 308 309 *cregs = *pregs; 310 311 /* Set the return value for the child. Note that this is not 312 actually restored by the syscall exit path, but we put it 313 here for consistency in case of signals. */ 314 cregs->gr[28] = 0; /* child */ 315 316 /* 317 * We need to differentiate between a user fork and a 318 * kernel fork. We can't use user_mode, because the 319 * the syscall path doesn't save iaoq. Right now 320 * We rely on the fact that kernel_thread passes 321 * in zero for usp. 322 */ 323 if (usp == 1) { 324 /* kernel thread */ 325 cregs->ksp = (((unsigned long)(ti)) + THREAD_SZ_ALGN); 326 /* Must exit via ret_from_kernel_thread in order 327 * to call schedule_tail() 328 */ 329 cregs->kpc = (unsigned long) &ret_from_kernel_thread; 330 /* 331 * Copy function and argument to be called from 332 * ret_from_kernel_thread. 333 */ 334 #ifdef __LP64__ 335 cregs->gr[27] = pregs->gr[27]; 336 #endif 337 cregs->gr[26] = pregs->gr[26]; 338 cregs->gr[25] = pregs->gr[25]; 339 } else { 340 /* user thread */ 341 /* 342 * Note that the fork wrappers are responsible 343 * for setting gr[21]. 344 */ 345 346 /* Use same stack depth as parent */ 347 cregs->ksp = ((unsigned long)(ti)) 348 + (pregs->gr[21] & (THREAD_SIZE - 1)); 349 cregs->gr[30] = usp; 350 if (p->personality == PER_HPUX) { 351 #ifdef CONFIG_HPUX 352 cregs->kpc = (unsigned long) &hpux_child_return; 353 #else 354 BUG(); 355 #endif 356 } else { 357 cregs->kpc = (unsigned long) &child_return; 358 } 359 /* Setup thread TLS area from the 4th parameter in clone */ 360 if (clone_flags & CLONE_SETTLS) 361 cregs->cr27 = pregs->gr[23]; 362 363 } 364 365 return 0; 366 } 367 368 unsigned long thread_saved_pc(struct task_struct *t) 369 { 370 return t->thread.regs.kpc; 371 } 372 373 /* 374 * sys_execve() executes a new program. 375 */ 376 377 asmlinkage int sys_execve(struct pt_regs *regs) 378 { 379 int error; 380 char *filename; 381 382 filename = getname((const char __user *) regs->gr[26]); 383 error = PTR_ERR(filename); 384 if (IS_ERR(filename)) 385 goto out; 386 error = do_execve(filename, (char __user **) regs->gr[25], 387 (char __user **) regs->gr[24], regs); 388 if (error == 0) { 389 task_lock(current); 390 current->ptrace &= ~PT_DTRACE; 391 task_unlock(current); 392 } 393 putname(filename); 394 out: 395 396 return error; 397 } 398 399 unsigned long 400 get_wchan(struct task_struct *p) 401 { 402 struct unwind_frame_info info; 403 unsigned long ip; 404 int count = 0; 405 /* 406 * These bracket the sleeping functions.. 407 */ 408 409 unwind_frame_init_from_blocked_task(&info, p); 410 do { 411 if (unwind_once(&info) < 0) 412 return 0; 413 ip = info.ip; 414 if (!in_sched_functions(ip)) 415 return ip; 416 } while (count++ < 16); 417 return 0; 418 } 419