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 #include <linux/rcupdate.h> 52 53 #include <asm/io.h> 54 #include <asm/asm-offsets.h> 55 #include <asm/assembly.h> 56 #include <asm/pdc.h> 57 #include <asm/pdc_chassis.h> 58 #include <asm/pgalloc.h> 59 #include <asm/unwind.h> 60 #include <asm/sections.h> 61 62 /* 63 * The idle thread. There's no useful work to be 64 * done, so just try to conserve power and have a 65 * low exit latency (ie sit in a loop waiting for 66 * somebody to say that they'd like to reschedule) 67 */ 68 void cpu_idle(void) 69 { 70 set_thread_flag(TIF_POLLING_NRFLAG); 71 72 /* endless idle loop with no priority at all */ 73 while (1) { 74 rcu_idle_enter(); 75 while (!need_resched()) 76 barrier(); 77 rcu_idle_exit(); 78 schedule_preempt_disabled(); 79 check_pgt_cache(); 80 } 81 } 82 83 84 #define COMMAND_GLOBAL F_EXTEND(0xfffe0030) 85 #define CMD_RESET 5 /* reset any module */ 86 87 /* 88 ** The Wright Brothers and Gecko systems have a H/W problem 89 ** (Lasi...'nuf said) may cause a broadcast reset to lockup 90 ** the system. An HVERSION dependent PDC call was developed 91 ** to perform a "safe", platform specific broadcast reset instead 92 ** of kludging up all the code. 93 ** 94 ** Older machines which do not implement PDC_BROADCAST_RESET will 95 ** return (with an error) and the regular broadcast reset can be 96 ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET 97 ** the PDC call will not return (the system will be reset). 98 */ 99 void machine_restart(char *cmd) 100 { 101 #ifdef FASTBOOT_SELFTEST_SUPPORT 102 /* 103 ** If user has modified the Firmware Selftest Bitmap, 104 ** run the tests specified in the bitmap after the 105 ** system is rebooted w/PDC_DO_RESET. 106 ** 107 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests" 108 ** 109 ** Using "directed resets" at each processor with the MEM_TOC 110 ** vector cleared will also avoid running destructive 111 ** memory self tests. (Not implemented yet) 112 */ 113 if (ftc_bitmap) { 114 pdc_do_firm_test_reset(ftc_bitmap); 115 } 116 #endif 117 /* set up a new led state on systems shipped with a LED State panel */ 118 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 119 120 /* "Normal" system reset */ 121 pdc_do_reset(); 122 123 /* Nope...box should reset with just CMD_RESET now */ 124 gsc_writel(CMD_RESET, COMMAND_GLOBAL); 125 126 /* Wait for RESET to lay us to rest. */ 127 while (1) ; 128 129 } 130 131 void machine_halt(void) 132 { 133 /* 134 ** The LED/ChassisCodes are updated by the led_halt() 135 ** function, called by the reboot notifier chain. 136 */ 137 } 138 139 void (*chassis_power_off)(void); 140 141 /* 142 * This routine is called from sys_reboot to actually turn off the 143 * machine 144 */ 145 void machine_power_off(void) 146 { 147 /* If there is a registered power off handler, call it. */ 148 if (chassis_power_off) 149 chassis_power_off(); 150 151 /* Put the soft power button back under hardware control. 152 * If the user had already pressed the power button, the 153 * following call will immediately power off. */ 154 pdc_soft_power_button(0); 155 156 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 157 158 /* It seems we have no way to power the system off via 159 * software. The user has to press the button himself. */ 160 161 printk(KERN_EMERG "System shut down completed.\n" 162 "Please power this system off now."); 163 } 164 165 void (*pm_power_off)(void) = machine_power_off; 166 EXPORT_SYMBOL(pm_power_off); 167 168 /* 169 * Free current thread data structures etc.. 170 */ 171 void exit_thread(void) 172 { 173 } 174 175 void flush_thread(void) 176 { 177 /* Only needs to handle fpu stuff or perf monitors. 178 ** REVISIT: several arches implement a "lazy fpu state". 179 */ 180 } 181 182 void release_thread(struct task_struct *dead_task) 183 { 184 } 185 186 /* 187 * Fill in the FPU structure for a core dump. 188 */ 189 190 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r) 191 { 192 if (regs == NULL) 193 return 0; 194 195 memcpy(r, regs->fr, sizeof *r); 196 return 1; 197 } 198 199 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r) 200 { 201 memcpy(r, tsk->thread.regs.fr, sizeof(*r)); 202 return 1; 203 } 204 205 /* Note that "fork()" is implemented in terms of clone, with 206 parameters (SIGCHLD, regs->gr[30], regs). */ 207 int 208 sys_clone(unsigned long clone_flags, unsigned long usp, 209 struct pt_regs *regs) 210 { 211 /* Arugments from userspace are: 212 r26 = Clone flags. 213 r25 = Child stack. 214 r24 = parent_tidptr. 215 r23 = Is the TLS storage descriptor 216 r22 = child_tidptr 217 218 However, these last 3 args are only examined 219 if the proper flags are set. */ 220 int __user *parent_tidptr = (int __user *)regs->gr[24]; 221 int __user *child_tidptr = (int __user *)regs->gr[22]; 222 223 /* usp must be word aligned. This also prevents users from 224 * passing in the value 1 (which is the signal for a special 225 * return for a kernel thread) */ 226 usp = ALIGN(usp, 4); 227 228 /* A zero value for usp means use the current stack */ 229 if (usp == 0) 230 usp = regs->gr[30]; 231 232 return do_fork(clone_flags, usp, regs, 0, parent_tidptr, child_tidptr); 233 } 234 235 int 236 sys_vfork(struct pt_regs *regs) 237 { 238 return do_fork(CLONE_VFORK | CLONE_VM | SIGCHLD, regs->gr[30], regs, 0, NULL, NULL); 239 } 240 241 int 242 copy_thread(unsigned long clone_flags, unsigned long usp, 243 unsigned long arg, 244 struct task_struct *p, struct pt_regs *pregs) 245 { 246 struct pt_regs * cregs = &(p->thread.regs); 247 void *stack = task_stack_page(p); 248 249 /* We have to use void * instead of a function pointer, because 250 * function pointers aren't a pointer to the function on 64-bit. 251 * Make them const so the compiler knows they live in .text */ 252 extern void * const ret_from_kernel_thread; 253 extern void * const child_return; 254 #ifdef CONFIG_HPUX 255 extern void * const hpux_child_return; 256 #endif 257 if (unlikely(p->flags & PF_KTHREAD)) { 258 memset(cregs, 0, sizeof(struct pt_regs)); 259 if (!usp) /* idle thread */ 260 return 0; 261 262 /* kernel thread */ 263 /* Must exit via ret_from_kernel_thread in order 264 * to call schedule_tail() 265 */ 266 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; 267 cregs->kpc = (unsigned long) &ret_from_kernel_thread; 268 /* 269 * Copy function and argument to be called from 270 * ret_from_kernel_thread. 271 */ 272 #ifdef CONFIG_64BIT 273 cregs->gr[27] = ((unsigned long *)usp)[3]; 274 cregs->gr[26] = ((unsigned long *)usp)[2]; 275 #else 276 cregs->gr[26] = usp; 277 #endif 278 cregs->gr[25] = arg; 279 } else { 280 /* user thread */ 281 cregs->gr[30] = usp; 282 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; 283 if (personality(p->personality) == PER_HPUX) { 284 #ifdef CONFIG_HPUX 285 cregs->kpc = (unsigned long) &hpux_child_return; 286 #else 287 BUG(); 288 #endif 289 } else { 290 cregs->kpc = (unsigned long) &child_return; 291 } 292 /* Setup thread TLS area from the 4th parameter in clone */ 293 if (clone_flags & CLONE_SETTLS) 294 cregs->cr27 = pregs->gr[23]; 295 } 296 297 return 0; 298 } 299 300 unsigned long thread_saved_pc(struct task_struct *t) 301 { 302 return t->thread.regs.kpc; 303 } 304 305 unsigned long 306 get_wchan(struct task_struct *p) 307 { 308 struct unwind_frame_info info; 309 unsigned long ip; 310 int count = 0; 311 312 if (!p || p == current || p->state == TASK_RUNNING) 313 return 0; 314 315 /* 316 * These bracket the sleeping functions.. 317 */ 318 319 unwind_frame_init_from_blocked_task(&info, p); 320 do { 321 if (unwind_once(&info) < 0) 322 return 0; 323 ip = info.ip; 324 if (!in_sched_functions(ip)) 325 return ip; 326 } while (count++ < 16); 327 return 0; 328 } 329 330 #ifdef CONFIG_64BIT 331 void *dereference_function_descriptor(void *ptr) 332 { 333 Elf64_Fdesc *desc = ptr; 334 void *p; 335 336 if (!probe_kernel_address(&desc->addr, p)) 337 ptr = p; 338 return ptr; 339 } 340 #endif 341