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/fs.h> 42 #include <linux/module.h> 43 #include <linux/personality.h> 44 #include <linux/ptrace.h> 45 #include <linux/sched.h> 46 #include <linux/slab.h> 47 #include <linux/stddef.h> 48 #include <linux/unistd.h> 49 #include <linux/kallsyms.h> 50 #include <linux/uaccess.h> 51 52 #include <asm/io.h> 53 #include <asm/asm-offsets.h> 54 #include <asm/pdc.h> 55 #include <asm/pdc_chassis.h> 56 #include <asm/pgalloc.h> 57 #include <asm/unwind.h> 58 #include <asm/sections.h> 59 60 /* 61 * The idle thread. There's no useful work to be 62 * done, so just try to conserve power and have a 63 * low exit latency (ie sit in a loop waiting for 64 * somebody to say that they'd like to reschedule) 65 */ 66 void cpu_idle(void) 67 { 68 set_thread_flag(TIF_POLLING_NRFLAG); 69 70 /* endless idle loop with no priority at all */ 71 while (1) { 72 while (!need_resched()) 73 barrier(); 74 preempt_enable_no_resched(); 75 schedule(); 76 preempt_disable(); 77 check_pgt_cache(); 78 } 79 } 80 81 82 #define COMMAND_GLOBAL F_EXTEND(0xfffe0030) 83 #define CMD_RESET 5 /* reset any module */ 84 85 /* 86 ** The Wright Brothers and Gecko systems have a H/W problem 87 ** (Lasi...'nuf said) may cause a broadcast reset to lockup 88 ** the system. An HVERSION dependent PDC call was developed 89 ** to perform a "safe", platform specific broadcast reset instead 90 ** of kludging up all the code. 91 ** 92 ** Older machines which do not implement PDC_BROADCAST_RESET will 93 ** return (with an error) and the regular broadcast reset can be 94 ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET 95 ** the PDC call will not return (the system will be reset). 96 */ 97 void machine_restart(char *cmd) 98 { 99 #ifdef FASTBOOT_SELFTEST_SUPPORT 100 /* 101 ** If user has modified the Firmware Selftest Bitmap, 102 ** run the tests specified in the bitmap after the 103 ** system is rebooted w/PDC_DO_RESET. 104 ** 105 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests" 106 ** 107 ** Using "directed resets" at each processor with the MEM_TOC 108 ** vector cleared will also avoid running destructive 109 ** memory self tests. (Not implemented yet) 110 */ 111 if (ftc_bitmap) { 112 pdc_do_firm_test_reset(ftc_bitmap); 113 } 114 #endif 115 /* set up a new led state on systems shipped with a LED State panel */ 116 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 117 118 /* "Normal" system reset */ 119 pdc_do_reset(); 120 121 /* Nope...box should reset with just CMD_RESET now */ 122 gsc_writel(CMD_RESET, COMMAND_GLOBAL); 123 124 /* Wait for RESET to lay us to rest. */ 125 while (1) ; 126 127 } 128 129 void machine_halt(void) 130 { 131 /* 132 ** The LED/ChassisCodes are updated by the led_halt() 133 ** function, called by the reboot notifier chain. 134 */ 135 } 136 137 void (*chassis_power_off)(void); 138 139 /* 140 * This routine is called from sys_reboot to actually turn off the 141 * machine 142 */ 143 void machine_power_off(void) 144 { 145 /* If there is a registered power off handler, call it. */ 146 if (chassis_power_off) 147 chassis_power_off(); 148 149 /* Put the soft power button back under hardware control. 150 * If the user had already pressed the power button, the 151 * following call will immediately power off. */ 152 pdc_soft_power_button(0); 153 154 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 155 156 /* It seems we have no way to power the system off via 157 * software. The user has to press the button himself. */ 158 159 printk(KERN_EMERG "System shut down completed.\n" 160 "Please power this system off now."); 161 } 162 163 void (*pm_power_off)(void) = machine_power_off; 164 EXPORT_SYMBOL(pm_power_off); 165 166 /* 167 * Create a kernel thread 168 */ 169 170 extern pid_t __kernel_thread(int (*fn)(void *), void *arg, unsigned long flags); 171 pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 172 { 173 174 /* 175 * FIXME: Once we are sure we don't need any debug here, 176 * kernel_thread can become a #define. 177 */ 178 179 return __kernel_thread(fn, arg, flags); 180 } 181 EXPORT_SYMBOL(kernel_thread); 182 183 /* 184 * Free current thread data structures etc.. 185 */ 186 void exit_thread(void) 187 { 188 } 189 190 void flush_thread(void) 191 { 192 /* Only needs to handle fpu stuff or perf monitors. 193 ** REVISIT: several arches implement a "lazy fpu state". 194 */ 195 set_fs(USER_DS); 196 } 197 198 void release_thread(struct task_struct *dead_task) 199 { 200 } 201 202 /* 203 * Fill in the FPU structure for a core dump. 204 */ 205 206 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r) 207 { 208 if (regs == NULL) 209 return 0; 210 211 memcpy(r, regs->fr, sizeof *r); 212 return 1; 213 } 214 215 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r) 216 { 217 memcpy(r, tsk->thread.regs.fr, sizeof(*r)); 218 return 1; 219 } 220 221 /* Note that "fork()" is implemented in terms of clone, with 222 parameters (SIGCHLD, regs->gr[30], regs). */ 223 int 224 sys_clone(unsigned long clone_flags, unsigned long usp, 225 struct pt_regs *regs) 226 { 227 /* Arugments from userspace are: 228 r26 = Clone flags. 229 r25 = Child stack. 230 r24 = parent_tidptr. 231 r23 = Is the TLS storage descriptor 232 r22 = child_tidptr 233 234 However, these last 3 args are only examined 235 if the proper flags are set. */ 236 int __user *parent_tidptr = (int __user *)regs->gr[24]; 237 int __user *child_tidptr = (int __user *)regs->gr[22]; 238 239 /* usp must be word aligned. This also prevents users from 240 * passing in the value 1 (which is the signal for a special 241 * return for a kernel thread) */ 242 usp = ALIGN(usp, 4); 243 244 /* A zero value for usp means use the current stack */ 245 if (usp == 0) 246 usp = regs->gr[30]; 247 248 return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr); 249 } 250 251 int 252 sys_vfork(struct pt_regs *regs) 253 { 254 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL); 255 } 256 257 int 258 copy_thread(unsigned long clone_flags, unsigned long usp, 259 unsigned long unused, /* in ia64 this is "user_stack_size" */ 260 struct task_struct * p, struct pt_regs * pregs) 261 { 262 struct pt_regs * cregs = &(p->thread.regs); 263 void *stack = task_stack_page(p); 264 265 /* We have to use void * instead of a function pointer, because 266 * function pointers aren't a pointer to the function on 64-bit. 267 * Make them const so the compiler knows they live in .text */ 268 extern void * const ret_from_kernel_thread; 269 extern void * const child_return; 270 #ifdef CONFIG_HPUX 271 extern void * const hpux_child_return; 272 #endif 273 274 *cregs = *pregs; 275 276 /* Set the return value for the child. Note that this is not 277 actually restored by the syscall exit path, but we put it 278 here for consistency in case of signals. */ 279 cregs->gr[28] = 0; /* child */ 280 281 /* 282 * We need to differentiate between a user fork and a 283 * kernel fork. We can't use user_mode, because the 284 * the syscall path doesn't save iaoq. Right now 285 * We rely on the fact that kernel_thread passes 286 * in zero for usp. 287 */ 288 if (usp == 1) { 289 /* kernel thread */ 290 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN; 291 /* Must exit via ret_from_kernel_thread in order 292 * to call schedule_tail() 293 */ 294 cregs->kpc = (unsigned long) &ret_from_kernel_thread; 295 /* 296 * Copy function and argument to be called from 297 * ret_from_kernel_thread. 298 */ 299 #ifdef CONFIG_64BIT 300 cregs->gr[27] = pregs->gr[27]; 301 #endif 302 cregs->gr[26] = pregs->gr[26]; 303 cregs->gr[25] = pregs->gr[25]; 304 } else { 305 /* user thread */ 306 /* 307 * Note that the fork wrappers are responsible 308 * for setting gr[21]. 309 */ 310 311 /* Use same stack depth as parent */ 312 cregs->ksp = (unsigned long)stack 313 + (pregs->gr[21] & (THREAD_SIZE - 1)); 314 cregs->gr[30] = usp; 315 if (p->personality == PER_HPUX) { 316 #ifdef CONFIG_HPUX 317 cregs->kpc = (unsigned long) &hpux_child_return; 318 #else 319 BUG(); 320 #endif 321 } else { 322 cregs->kpc = (unsigned long) &child_return; 323 } 324 /* Setup thread TLS area from the 4th parameter in clone */ 325 if (clone_flags & CLONE_SETTLS) 326 cregs->cr27 = pregs->gr[23]; 327 328 } 329 330 return 0; 331 } 332 333 unsigned long thread_saved_pc(struct task_struct *t) 334 { 335 return t->thread.regs.kpc; 336 } 337 338 /* 339 * sys_execve() executes a new program. 340 */ 341 342 asmlinkage int sys_execve(struct pt_regs *regs) 343 { 344 int error; 345 char *filename; 346 347 filename = getname((const char __user *) regs->gr[26]); 348 error = PTR_ERR(filename); 349 if (IS_ERR(filename)) 350 goto out; 351 error = do_execve(filename, 352 (const char __user *const __user *) regs->gr[25], 353 (const char __user *const __user *) regs->gr[24], 354 regs); 355 putname(filename); 356 out: 357 358 return error; 359 } 360 361 extern int __execve(const char *filename, 362 const char *const argv[], 363 const char *const envp[], struct task_struct *task); 364 int kernel_execve(const char *filename, 365 const char *const argv[], 366 const char *const envp[]) 367 { 368 return __execve(filename, argv, envp, current); 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 if (!p || p == current || p->state == TASK_RUNNING) 379 return 0; 380 381 /* 382 * These bracket the sleeping functions.. 383 */ 384 385 unwind_frame_init_from_blocked_task(&info, p); 386 do { 387 if (unwind_once(&info) < 0) 388 return 0; 389 ip = info.ip; 390 if (!in_sched_functions(ip)) 391 return ip; 392 } while (count++ < 16); 393 return 0; 394 } 395 396 #ifdef CONFIG_64BIT 397 void *dereference_function_descriptor(void *ptr) 398 { 399 Elf64_Fdesc *desc = ptr; 400 void *p; 401 402 if (!probe_kernel_address(&desc->addr, p)) 403 ptr = p; 404 return ptr; 405 } 406 #endif 407