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) 2001-2007 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 /* 58 * The idle thread. There's no useful work to be 59 * done, so just try to conserve power and have a 60 * low exit latency (ie sit in a loop waiting for 61 * somebody to say that they'd like to reschedule) 62 */ 63 void cpu_idle(void) 64 { 65 set_thread_flag(TIF_POLLING_NRFLAG); 66 67 /* endless idle loop with no priority at all */ 68 while (1) { 69 while (!need_resched()) 70 barrier(); 71 preempt_enable_no_resched(); 72 schedule(); 73 preempt_disable(); 74 check_pgt_cache(); 75 } 76 } 77 78 79 #define COMMAND_GLOBAL F_EXTEND(0xfffe0030) 80 #define CMD_RESET 5 /* reset any module */ 81 82 /* 83 ** The Wright Brothers and Gecko systems have a H/W problem 84 ** (Lasi...'nuf said) may cause a broadcast reset to lockup 85 ** the system. An HVERSION dependent PDC call was developed 86 ** to perform a "safe", platform specific broadcast reset instead 87 ** of kludging up all the code. 88 ** 89 ** Older machines which do not implement PDC_BROADCAST_RESET will 90 ** return (with an error) and the regular broadcast reset can be 91 ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET 92 ** the PDC call will not return (the system will be reset). 93 */ 94 void machine_restart(char *cmd) 95 { 96 #ifdef FASTBOOT_SELFTEST_SUPPORT 97 /* 98 ** If user has modified the Firmware Selftest Bitmap, 99 ** run the tests specified in the bitmap after the 100 ** system is rebooted w/PDC_DO_RESET. 101 ** 102 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests" 103 ** 104 ** Using "directed resets" at each processor with the MEM_TOC 105 ** vector cleared will also avoid running destructive 106 ** memory self tests. (Not implemented yet) 107 */ 108 if (ftc_bitmap) { 109 pdc_do_firm_test_reset(ftc_bitmap); 110 } 111 #endif 112 /* set up a new led state on systems shipped with a LED State panel */ 113 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 114 115 /* "Normal" system reset */ 116 pdc_do_reset(); 117 118 /* Nope...box should reset with just CMD_RESET now */ 119 gsc_writel(CMD_RESET, COMMAND_GLOBAL); 120 121 /* Wait for RESET to lay us to rest. */ 122 while (1) ; 123 124 } 125 126 void machine_halt(void) 127 { 128 /* 129 ** The LED/ChassisCodes are updated by the led_halt() 130 ** function, called by the reboot notifier chain. 131 */ 132 } 133 134 void (*chassis_power_off)(void); 135 136 /* 137 * This routine is called from sys_reboot to actually turn off the 138 * machine 139 */ 140 void machine_power_off(void) 141 { 142 /* If there is a registered power off handler, call it. */ 143 if (chassis_power_off) 144 chassis_power_off(); 145 146 /* Put the soft power button back under hardware control. 147 * If the user had already pressed the power button, the 148 * following call will immediately power off. */ 149 pdc_soft_power_button(0); 150 151 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 152 153 /* It seems we have no way to power the system off via 154 * software. The user has to press the button himself. */ 155 156 printk(KERN_EMERG "System shut down completed.\n" 157 KERN_EMERG "Please power this system off now."); 158 } 159 160 void (*pm_power_off)(void) = machine_power_off; 161 EXPORT_SYMBOL(pm_power_off); 162 163 /* 164 * Create a kernel thread 165 */ 166 167 extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); 168 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 169 { 170 171 /* 172 * FIXME: Once we are sure we don't need any debug here, 173 * kernel_thread can become a #define. 174 */ 175 176 return __kernel_thread(fn, arg, flags); 177 } 178 EXPORT_SYMBOL(kernel_thread); 179 180 /* 181 * Free current thread data structures etc.. 182 */ 183 void exit_thread(void) 184 { 185 } 186 187 void flush_thread(void) 188 { 189 /* Only needs to handle fpu stuff or perf monitors. 190 ** REVISIT: several arches implement a "lazy fpu state". 191 */ 192 set_fs(USER_DS); 193 } 194 195 void release_thread(struct task_struct *dead_task) 196 { 197 } 198 199 /* 200 * Fill in the FPU structure for a core dump. 201 */ 202 203 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r) 204 { 205 if (regs == NULL) 206 return 0; 207 208 memcpy(r, regs->fr, sizeof *r); 209 return 1; 210 } 211 212 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r) 213 { 214 memcpy(r, tsk->thread.regs.fr, sizeof(*r)); 215 return 1; 216 } 217 218 /* Note that "fork()" is implemented in terms of clone, with 219 parameters (SIGCHLD, regs->gr[30], regs). */ 220 int 221 sys_clone(unsigned long clone_flags, unsigned long usp, 222 struct pt_regs *regs) 223 { 224 /* Arugments from userspace are: 225 r26 = Clone flags. 226 r25 = Child stack. 227 r24 = parent_tidptr. 228 r23 = Is the TLS storage descriptor 229 r22 = child_tidptr 230 231 However, these last 3 args are only examined 232 if the proper flags are set. */ 233 int __user *child_tidptr; 234 int __user *parent_tidptr; 235 236 /* usp must be word aligned. This also prevents users from 237 * passing in the value 1 (which is the signal for a special 238 * return for a kernel thread) */ 239 usp = ALIGN(usp, 4); 240 241 /* A zero value for usp means use the current stack */ 242 if (usp == 0) 243 usp = regs->gr[30]; 244 245 if (clone_flags & CLONE_PARENT_SETTID) 246 parent_tidptr = (int __user *)regs->gr[24]; 247 else 248 parent_tidptr = NULL; 249 250 if (clone_flags & (CLONE_CHILD_SETTID | CLONE_CHILD_CLEARTID)) 251 child_tidptr = (int __user *)regs->gr[22]; 252 else 253 child_tidptr = NULL; 254 255 return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr); 256 } 257 258 int 259 sys_vfork(struct pt_regs *regs) 260 { 261 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL); 262 } 263 264 int 265 copy_thread(int nr, unsigned long clone_flags, unsigned long usp, 266 unsigned long unused, /* in ia64 this is "user_stack_size" */ 267 struct task_struct * p, struct pt_regs * pregs) 268 { 269 struct pt_regs * cregs = &(p->thread.regs); 270 void *stack = task_stack_page(p); 271 272 /* We have to use void * instead of a function pointer, because 273 * function pointers aren't a pointer to the function on 64-bit. 274 * Make them const so the compiler knows they live in .text */ 275 extern void * const ret_from_kernel_thread; 276 extern void * const child_return; 277 #ifdef CONFIG_HPUX 278 extern void * const hpux_child_return; 279 #endif 280 281 *cregs = *pregs; 282 283 /* Set the return value for the child. Note that this is not 284 actually restored by the syscall exit path, but we put it 285 here for consistency in case of signals. */ 286 cregs->gr[28] = 0; /* child */ 287 288 /* 289 * We need to differentiate between a user fork and a 290 * kernel fork. We can't use user_mode, because the 291 * the syscall path doesn't save iaoq. Right now 292 * We rely on the fact that kernel_thread passes 293 * in zero for usp. 294 */ 295 if (usp == 1) { 296 /* kernel thread */ 297 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN; 298 /* Must exit via ret_from_kernel_thread in order 299 * to call schedule_tail() 300 */ 301 cregs->kpc = (unsigned long) &ret_from_kernel_thread; 302 /* 303 * Copy function and argument to be called from 304 * ret_from_kernel_thread. 305 */ 306 #ifdef CONFIG_64BIT 307 cregs->gr[27] = pregs->gr[27]; 308 #endif 309 cregs->gr[26] = pregs->gr[26]; 310 cregs->gr[25] = pregs->gr[25]; 311 } else { 312 /* user thread */ 313 /* 314 * Note that the fork wrappers are responsible 315 * for setting gr[21]. 316 */ 317 318 /* Use same stack depth as parent */ 319 cregs->ksp = (unsigned long)stack 320 + (pregs->gr[21] & (THREAD_SIZE - 1)); 321 cregs->gr[30] = usp; 322 if (p->personality == PER_HPUX) { 323 #ifdef CONFIG_HPUX 324 cregs->kpc = (unsigned long) &hpux_child_return; 325 #else 326 BUG(); 327 #endif 328 } else { 329 cregs->kpc = (unsigned long) &child_return; 330 } 331 /* Setup thread TLS area from the 4th parameter in clone */ 332 if (clone_flags & CLONE_SETTLS) 333 cregs->cr27 = pregs->gr[23]; 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 * __user *) regs->gr[25], 359 (char __user * __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 extern int __execve(const char *filename, char *const argv[], 372 char *const envp[], struct task_struct *task); 373 int kernel_execve(const char *filename, char *const argv[], char *const envp[]) 374 { 375 return __execve(filename, argv, envp, current); 376 } 377 378 unsigned long 379 get_wchan(struct task_struct *p) 380 { 381 struct unwind_frame_info info; 382 unsigned long ip; 383 int count = 0; 384 385 if (!p || p == current || p->state == TASK_RUNNING) 386 return 0; 387 388 /* 389 * These bracket the sleeping functions.. 390 */ 391 392 unwind_frame_init_from_blocked_task(&info, p); 393 do { 394 if (unwind_once(&info) < 0) 395 return 0; 396 ip = info.ip; 397 if (!in_sched_functions(ip)) 398 return ip; 399 } while (count++ < 16); 400 return 0; 401 } 402