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-lixux.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 int __user *user_tid = (int __user *)regs->gr[26]; 249 250 /* usp must be word aligned. This also prevents users from 251 * passing in the value 1 (which is the signal for a special 252 * return for a kernel thread) */ 253 usp = ALIGN(usp, 4); 254 255 /* A zero value for usp means use the current stack */ 256 if(usp == 0) 257 usp = regs->gr[30]; 258 259 return do_fork(clone_flags, usp, regs, 0, user_tid, NULL); 260 } 261 262 int 263 sys_vfork(struct pt_regs *regs) 264 { 265 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL); 266 } 267 268 int 269 copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 270 unsigned long unused, /* in ia64 this is "user_stack_size" */ 271 struct task_struct * p, struct pt_regs * pregs) 272 { 273 struct pt_regs * cregs = &(p->thread.regs); 274 struct thread_info *ti = p->thread_info; 275 276 /* We have to use void * instead of a function pointer, because 277 * function pointers aren't a pointer to the function on 64-bit. 278 * Make them const so the compiler knows they live in .text */ 279 extern void * const ret_from_kernel_thread; 280 extern void * const child_return; 281 #ifdef CONFIG_HPUX 282 extern void * const hpux_child_return; 283 #endif 284 285 *cregs = *pregs; 286 287 /* Set the return value for the child. Note that this is not 288 actually restored by the syscall exit path, but we put it 289 here for consistency in case of signals. */ 290 cregs->gr[28] = 0; /* child */ 291 292 /* 293 * We need to differentiate between a user fork and a 294 * kernel fork. We can't use user_mode, because the 295 * the syscall path doesn't save iaoq. Right now 296 * We rely on the fact that kernel_thread passes 297 * in zero for usp. 298 */ 299 if (usp == 1) { 300 /* kernel thread */ 301 cregs->ksp = (((unsigned long)(ti)) + THREAD_SZ_ALGN); 302 /* Must exit via ret_from_kernel_thread in order 303 * to call schedule_tail() 304 */ 305 cregs->kpc = (unsigned long) &ret_from_kernel_thread; 306 /* 307 * Copy function and argument to be called from 308 * ret_from_kernel_thread. 309 */ 310 #ifdef __LP64__ 311 cregs->gr[27] = pregs->gr[27]; 312 #endif 313 cregs->gr[26] = pregs->gr[26]; 314 cregs->gr[25] = pregs->gr[25]; 315 } else { 316 /* user thread */ 317 /* 318 * Note that the fork wrappers are responsible 319 * for setting gr[21]. 320 */ 321 322 /* Use same stack depth as parent */ 323 cregs->ksp = ((unsigned long)(ti)) 324 + (pregs->gr[21] & (THREAD_SIZE - 1)); 325 cregs->gr[30] = usp; 326 if (p->personality == PER_HPUX) { 327 #ifdef CONFIG_HPUX 328 cregs->kpc = (unsigned long) &hpux_child_return; 329 #else 330 BUG(); 331 #endif 332 } else { 333 cregs->kpc = (unsigned long) &child_return; 334 } 335 } 336 337 return 0; 338 } 339 340 unsigned long thread_saved_pc(struct task_struct *t) 341 { 342 return t->thread.regs.kpc; 343 } 344 345 /* 346 * sys_execve() executes a new program. 347 */ 348 349 asmlinkage int sys_execve(struct pt_regs *regs) 350 { 351 int error; 352 char *filename; 353 354 filename = getname((const char __user *) regs->gr[26]); 355 error = PTR_ERR(filename); 356 if (IS_ERR(filename)) 357 goto out; 358 error = do_execve(filename, (char __user **) regs->gr[25], 359 (char __user **) regs->gr[24], regs); 360 if (error == 0) { 361 task_lock(current); 362 current->ptrace &= ~PT_DTRACE; 363 task_unlock(current); 364 } 365 putname(filename); 366 out: 367 368 return error; 369 } 370 371 unsigned long 372 get_wchan(struct task_struct *p) 373 { 374 struct unwind_frame_info info; 375 unsigned long ip; 376 int count = 0; 377 /* 378 * These bracket the sleeping functions.. 379 */ 380 381 unwind_frame_init_from_blocked_task(&info, p); 382 do { 383 if (unwind_once(&info) < 0) 384 return 0; 385 ip = info.ip; 386 if (!in_sched_functions(ip)) 387 return ip; 388 } while (count++ < 16); 389 return 0; 390 } 391