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) 2001-2014 Helge Deller <deller@gmx.de> 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/cpu.h> 43 #include <linux/module.h> 44 #include <linux/personality.h> 45 #include <linux/ptrace.h> 46 #include <linux/sched.h> 47 #include <linux/sched/debug.h> 48 #include <linux/sched/task.h> 49 #include <linux/sched/task_stack.h> 50 #include <linux/slab.h> 51 #include <linux/stddef.h> 52 #include <linux/unistd.h> 53 #include <linux/kallsyms.h> 54 #include <linux/uaccess.h> 55 #include <linux/rcupdate.h> 56 #include <linux/random.h> 57 #include <linux/nmi.h> 58 59 #include <asm/io.h> 60 #include <asm/asm-offsets.h> 61 #include <asm/assembly.h> 62 #include <asm/pdc.h> 63 #include <asm/pdc_chassis.h> 64 #include <asm/pgalloc.h> 65 #include <asm/unwind.h> 66 #include <asm/sections.h> 67 68 #define COMMAND_GLOBAL F_EXTEND(0xfffe0030) 69 #define CMD_RESET 5 /* reset any module */ 70 71 /* 72 ** The Wright Brothers and Gecko systems have a H/W problem 73 ** (Lasi...'nuf said) may cause a broadcast reset to lockup 74 ** the system. An HVERSION dependent PDC call was developed 75 ** to perform a "safe", platform specific broadcast reset instead 76 ** of kludging up all the code. 77 ** 78 ** Older machines which do not implement PDC_BROADCAST_RESET will 79 ** return (with an error) and the regular broadcast reset can be 80 ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET 81 ** the PDC call will not return (the system will be reset). 82 */ 83 void machine_restart(char *cmd) 84 { 85 #ifdef FASTBOOT_SELFTEST_SUPPORT 86 /* 87 ** If user has modified the Firmware Selftest Bitmap, 88 ** run the tests specified in the bitmap after the 89 ** system is rebooted w/PDC_DO_RESET. 90 ** 91 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests" 92 ** 93 ** Using "directed resets" at each processor with the MEM_TOC 94 ** vector cleared will also avoid running destructive 95 ** memory self tests. (Not implemented yet) 96 */ 97 if (ftc_bitmap) { 98 pdc_do_firm_test_reset(ftc_bitmap); 99 } 100 #endif 101 /* set up a new led state on systems shipped with a LED State panel */ 102 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 103 104 /* "Normal" system reset */ 105 pdc_do_reset(); 106 107 /* Nope...box should reset with just CMD_RESET now */ 108 gsc_writel(CMD_RESET, COMMAND_GLOBAL); 109 110 /* Wait for RESET to lay us to rest. */ 111 while (1) ; 112 113 } 114 115 void machine_halt(void) 116 { 117 /* 118 ** The LED/ChassisCodes are updated by the led_halt() 119 ** function, called by the reboot notifier chain. 120 */ 121 } 122 123 void (*chassis_power_off)(void); 124 125 /* 126 * This routine is called from sys_reboot to actually turn off the 127 * machine 128 */ 129 void machine_power_off(void) 130 { 131 /* If there is a registered power off handler, call it. */ 132 if (chassis_power_off) 133 chassis_power_off(); 134 135 /* Put the soft power button back under hardware control. 136 * If the user had already pressed the power button, the 137 * following call will immediately power off. */ 138 pdc_soft_power_button(0); 139 140 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 141 142 /* It seems we have no way to power the system off via 143 * software. The user has to press the button himself. */ 144 145 printk(KERN_EMERG "System shut down completed.\n" 146 "Please power this system off now."); 147 148 /* prevent soft lockup/stalled CPU messages for endless loop. */ 149 rcu_sysrq_start(); 150 lockup_detector_soft_poweroff(); 151 for (;;); 152 } 153 154 void (*pm_power_off)(void) = machine_power_off; 155 EXPORT_SYMBOL(pm_power_off); 156 157 void flush_thread(void) 158 { 159 /* Only needs to handle fpu stuff or perf monitors. 160 ** REVISIT: several arches implement a "lazy fpu state". 161 */ 162 } 163 164 void release_thread(struct task_struct *dead_task) 165 { 166 } 167 168 /* 169 * Fill in the FPU structure for a core dump. 170 */ 171 172 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r) 173 { 174 if (regs == NULL) 175 return 0; 176 177 memcpy(r, regs->fr, sizeof *r); 178 return 1; 179 } 180 181 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r) 182 { 183 memcpy(r, tsk->thread.regs.fr, sizeof(*r)); 184 return 1; 185 } 186 187 /* 188 * Idle thread support 189 * 190 * Detect when running on QEMU with SeaBIOS PDC Firmware and let 191 * QEMU idle the host too. 192 */ 193 194 int running_on_qemu __read_mostly; 195 196 void __cpuidle arch_cpu_idle_dead(void) 197 { 198 /* nop on real hardware, qemu will offline CPU. */ 199 asm volatile("or %%r31,%%r31,%%r31\n":::); 200 } 201 202 void __cpuidle arch_cpu_idle(void) 203 { 204 local_irq_enable(); 205 206 /* nop on real hardware, qemu will idle sleep. */ 207 asm volatile("or %%r10,%%r10,%%r10\n":::); 208 } 209 210 static int __init parisc_idle_init(void) 211 { 212 const char *marker; 213 214 /* check QEMU/SeaBIOS marker in PAGE0 */ 215 marker = (char *) &PAGE0->pad0; 216 running_on_qemu = (memcmp(marker, "SeaBIOS", 8) == 0); 217 218 if (!running_on_qemu) 219 cpu_idle_poll_ctrl(1); 220 221 return 0; 222 } 223 arch_initcall(parisc_idle_init); 224 225 /* 226 * Copy architecture-specific thread state 227 */ 228 int 229 copy_thread(unsigned long clone_flags, unsigned long usp, 230 unsigned long kthread_arg, struct task_struct *p) 231 { 232 struct pt_regs *cregs = &(p->thread.regs); 233 void *stack = task_stack_page(p); 234 235 /* We have to use void * instead of a function pointer, because 236 * function pointers aren't a pointer to the function on 64-bit. 237 * Make them const so the compiler knows they live in .text */ 238 extern void * const ret_from_kernel_thread; 239 extern void * const child_return; 240 241 if (unlikely(p->flags & PF_KTHREAD)) { 242 /* kernel thread */ 243 memset(cregs, 0, sizeof(struct pt_regs)); 244 if (!usp) /* idle thread */ 245 return 0; 246 /* Must exit via ret_from_kernel_thread in order 247 * to call schedule_tail() 248 */ 249 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; 250 cregs->kpc = (unsigned long) &ret_from_kernel_thread; 251 /* 252 * Copy function and argument to be called from 253 * ret_from_kernel_thread. 254 */ 255 #ifdef CONFIG_64BIT 256 cregs->gr[27] = ((unsigned long *)usp)[3]; 257 cregs->gr[26] = ((unsigned long *)usp)[2]; 258 #else 259 cregs->gr[26] = usp; 260 #endif 261 cregs->gr[25] = kthread_arg; 262 } else { 263 /* user thread */ 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 if (usp) { 268 usp = ALIGN(usp, 4); 269 if (likely(usp)) 270 cregs->gr[30] = usp; 271 } 272 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; 273 cregs->kpc = (unsigned long) &child_return; 274 275 /* Setup thread TLS area from the 4th parameter in clone */ 276 if (clone_flags & CLONE_SETTLS) 277 cregs->cr27 = cregs->gr[23]; 278 } 279 280 return 0; 281 } 282 283 unsigned long 284 get_wchan(struct task_struct *p) 285 { 286 struct unwind_frame_info info; 287 unsigned long ip; 288 int count = 0; 289 290 if (!p || p == current || p->state == TASK_RUNNING) 291 return 0; 292 293 /* 294 * These bracket the sleeping functions.. 295 */ 296 297 unwind_frame_init_from_blocked_task(&info, p); 298 do { 299 if (unwind_once(&info) < 0) 300 return 0; 301 ip = info.ip; 302 if (!in_sched_functions(ip)) 303 return ip; 304 } while (count++ < 16); 305 return 0; 306 } 307 308 #ifdef CONFIG_64BIT 309 void *dereference_function_descriptor(void *ptr) 310 { 311 Elf64_Fdesc *desc = ptr; 312 void *p; 313 314 if (!probe_kernel_address(&desc->addr, p)) 315 ptr = p; 316 return ptr; 317 } 318 319 void *dereference_kernel_function_descriptor(void *ptr) 320 { 321 if (ptr < (void *)__start_opd || 322 ptr >= (void *)__end_opd) 323 return ptr; 324 325 return dereference_function_descriptor(ptr); 326 } 327 #endif 328 329 static inline unsigned long brk_rnd(void) 330 { 331 return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT; 332 } 333 334 unsigned long arch_randomize_brk(struct mm_struct *mm) 335 { 336 unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd()); 337 338 if (ret < mm->brk) 339 return mm->brk; 340 return ret; 341 } 342