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 (*chassis_power_off)(void); 116 117 /* 118 * This routine is called from sys_reboot to actually turn off the 119 * machine 120 */ 121 void machine_power_off(void) 122 { 123 /* If there is a registered power off handler, call it. */ 124 if (chassis_power_off) 125 chassis_power_off(); 126 127 /* Put the soft power button back under hardware control. 128 * If the user had already pressed the power button, the 129 * following call will immediately power off. */ 130 pdc_soft_power_button(0); 131 132 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 133 134 /* ipmi_poweroff may have been installed. */ 135 if (pm_power_off) 136 pm_power_off(); 137 138 /* It seems we have no way to power the system off via 139 * software. The user has to press the button himself. */ 140 141 printk(KERN_EMERG "System shut down completed.\n" 142 "Please power this system off now."); 143 144 /* prevent soft lockup/stalled CPU messages for endless loop. */ 145 rcu_sysrq_start(); 146 lockup_detector_soft_poweroff(); 147 for (;;); 148 } 149 150 void (*pm_power_off)(void); 151 EXPORT_SYMBOL(pm_power_off); 152 153 void machine_halt(void) 154 { 155 machine_power_off(); 156 } 157 158 void flush_thread(void) 159 { 160 /* Only needs to handle fpu stuff or perf monitors. 161 ** REVISIT: several arches implement a "lazy fpu state". 162 */ 163 } 164 165 void release_thread(struct task_struct *dead_task) 166 { 167 } 168 169 /* 170 * Fill in the FPU structure for a core dump. 171 */ 172 173 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r) 174 { 175 if (regs == NULL) 176 return 0; 177 178 memcpy(r, regs->fr, sizeof *r); 179 return 1; 180 } 181 182 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r) 183 { 184 memcpy(r, tsk->thread.regs.fr, sizeof(*r)); 185 return 1; 186 } 187 188 /* 189 * Idle thread support 190 * 191 * Detect when running on QEMU with SeaBIOS PDC Firmware and let 192 * QEMU idle the host too. 193 */ 194 195 int running_on_qemu __read_mostly; 196 197 void __cpuidle arch_cpu_idle_dead(void) 198 { 199 /* nop on real hardware, qemu will offline CPU. */ 200 asm volatile("or %%r31,%%r31,%%r31\n":::); 201 } 202 203 void __cpuidle arch_cpu_idle(void) 204 { 205 local_irq_enable(); 206 207 /* nop on real hardware, qemu will idle sleep. */ 208 asm volatile("or %%r10,%%r10,%%r10\n":::); 209 } 210 211 static int __init parisc_idle_init(void) 212 { 213 if (!running_on_qemu) 214 cpu_idle_poll_ctrl(1); 215 216 return 0; 217 } 218 arch_initcall(parisc_idle_init); 219 220 /* 221 * Copy architecture-specific thread state 222 */ 223 int 224 copy_thread(unsigned long clone_flags, unsigned long usp, 225 unsigned long kthread_arg, struct task_struct *p) 226 { 227 struct pt_regs *cregs = &(p->thread.regs); 228 void *stack = task_stack_page(p); 229 230 /* We have to use void * instead of a function pointer, because 231 * function pointers aren't a pointer to the function on 64-bit. 232 * Make them const so the compiler knows they live in .text */ 233 extern void * const ret_from_kernel_thread; 234 extern void * const child_return; 235 236 if (unlikely(p->flags & PF_KTHREAD)) { 237 /* kernel thread */ 238 memset(cregs, 0, sizeof(struct pt_regs)); 239 if (!usp) /* idle thread */ 240 return 0; 241 /* Must exit via ret_from_kernel_thread in order 242 * to call schedule_tail() 243 */ 244 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; 245 cregs->kpc = (unsigned long) &ret_from_kernel_thread; 246 /* 247 * Copy function and argument to be called from 248 * ret_from_kernel_thread. 249 */ 250 #ifdef CONFIG_64BIT 251 cregs->gr[27] = ((unsigned long *)usp)[3]; 252 cregs->gr[26] = ((unsigned long *)usp)[2]; 253 #else 254 cregs->gr[26] = usp; 255 #endif 256 cregs->gr[25] = kthread_arg; 257 } else { 258 /* user thread */ 259 /* usp must be word aligned. This also prevents users from 260 * passing in the value 1 (which is the signal for a special 261 * return for a kernel thread) */ 262 if (usp) { 263 usp = ALIGN(usp, 4); 264 if (likely(usp)) 265 cregs->gr[30] = usp; 266 } 267 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; 268 cregs->kpc = (unsigned long) &child_return; 269 270 /* Setup thread TLS area from the 4th parameter in clone */ 271 if (clone_flags & CLONE_SETTLS) 272 cregs->cr27 = cregs->gr[23]; 273 } 274 275 return 0; 276 } 277 278 unsigned long 279 get_wchan(struct task_struct *p) 280 { 281 struct unwind_frame_info info; 282 unsigned long ip; 283 int count = 0; 284 285 if (!p || p == current || p->state == TASK_RUNNING) 286 return 0; 287 288 /* 289 * These bracket the sleeping functions.. 290 */ 291 292 unwind_frame_init_from_blocked_task(&info, p); 293 do { 294 if (unwind_once(&info) < 0) 295 return 0; 296 ip = info.ip; 297 if (!in_sched_functions(ip)) 298 return ip; 299 } while (count++ < MAX_UNWIND_ENTRIES); 300 return 0; 301 } 302 303 #ifdef CONFIG_64BIT 304 void *dereference_function_descriptor(void *ptr) 305 { 306 Elf64_Fdesc *desc = ptr; 307 void *p; 308 309 if (!probe_kernel_address(&desc->addr, p)) 310 ptr = p; 311 return ptr; 312 } 313 314 void *dereference_kernel_function_descriptor(void *ptr) 315 { 316 if (ptr < (void *)__start_opd || 317 ptr >= (void *)__end_opd) 318 return ptr; 319 320 return dereference_function_descriptor(ptr); 321 } 322 #endif 323 324 static inline unsigned long brk_rnd(void) 325 { 326 return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT; 327 } 328 329 unsigned long arch_randomize_brk(struct mm_struct *mm) 330 { 331 unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd()); 332 333 if (ret < mm->brk) 334 return mm->brk; 335 return ret; 336 } 337