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/module.h> 43 #include <linux/personality.h> 44 #include <linux/ptrace.h> 45 #include <linux/sched.h> 46 #include <linux/sched/debug.h> 47 #include <linux/sched/task.h> 48 #include <linux/sched/task_stack.h> 49 #include <linux/slab.h> 50 #include <linux/stddef.h> 51 #include <linux/unistd.h> 52 #include <linux/kallsyms.h> 53 #include <linux/uaccess.h> 54 #include <linux/rcupdate.h> 55 #include <linux/random.h> 56 #include <linux/nmi.h> 57 58 #include <asm/io.h> 59 #include <asm/asm-offsets.h> 60 #include <asm/assembly.h> 61 #include <asm/pdc.h> 62 #include <asm/pdc_chassis.h> 63 #include <asm/pgalloc.h> 64 #include <asm/unwind.h> 65 #include <asm/sections.h> 66 67 #define COMMAND_GLOBAL F_EXTEND(0xfffe0030) 68 #define CMD_RESET 5 /* reset any module */ 69 70 /* 71 ** The Wright Brothers and Gecko systems have a H/W problem 72 ** (Lasi...'nuf said) may cause a broadcast reset to lockup 73 ** the system. An HVERSION dependent PDC call was developed 74 ** to perform a "safe", platform specific broadcast reset instead 75 ** of kludging up all the code. 76 ** 77 ** Older machines which do not implement PDC_BROADCAST_RESET will 78 ** return (with an error) and the regular broadcast reset can be 79 ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET 80 ** the PDC call will not return (the system will be reset). 81 */ 82 void machine_restart(char *cmd) 83 { 84 #ifdef FASTBOOT_SELFTEST_SUPPORT 85 /* 86 ** If user has modified the Firmware Selftest Bitmap, 87 ** run the tests specified in the bitmap after the 88 ** system is rebooted w/PDC_DO_RESET. 89 ** 90 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests" 91 ** 92 ** Using "directed resets" at each processor with the MEM_TOC 93 ** vector cleared will also avoid running destructive 94 ** memory self tests. (Not implemented yet) 95 */ 96 if (ftc_bitmap) { 97 pdc_do_firm_test_reset(ftc_bitmap); 98 } 99 #endif 100 /* set up a new led state on systems shipped with a LED State panel */ 101 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 102 103 /* "Normal" system reset */ 104 pdc_do_reset(); 105 106 /* Nope...box should reset with just CMD_RESET now */ 107 gsc_writel(CMD_RESET, COMMAND_GLOBAL); 108 109 /* Wait for RESET to lay us to rest. */ 110 while (1) ; 111 112 } 113 114 void machine_halt(void) 115 { 116 /* 117 ** The LED/ChassisCodes are updated by the led_halt() 118 ** function, called by the reboot notifier chain. 119 */ 120 } 121 122 void (*chassis_power_off)(void); 123 124 /* 125 * This routine is called from sys_reboot to actually turn off the 126 * machine 127 */ 128 void machine_power_off(void) 129 { 130 /* If there is a registered power off handler, call it. */ 131 if (chassis_power_off) 132 chassis_power_off(); 133 134 /* Put the soft power button back under hardware control. 135 * If the user had already pressed the power button, the 136 * following call will immediately power off. */ 137 pdc_soft_power_button(0); 138 139 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 140 141 /* It seems we have no way to power the system off via 142 * software. The user has to press the button himself. */ 143 144 printk(KERN_EMERG "System shut down completed.\n" 145 "Please power this system off now."); 146 147 /* prevent soft lockup/stalled CPU messages for endless loop. */ 148 rcu_sysrq_start(); 149 lockup_detector_soft_poweroff(); 150 for (;;); 151 } 152 153 void (*pm_power_off)(void) = machine_power_off; 154 EXPORT_SYMBOL(pm_power_off); 155 156 void flush_thread(void) 157 { 158 /* Only needs to handle fpu stuff or perf monitors. 159 ** REVISIT: several arches implement a "lazy fpu state". 160 */ 161 } 162 163 void release_thread(struct task_struct *dead_task) 164 { 165 } 166 167 /* 168 * Fill in the FPU structure for a core dump. 169 */ 170 171 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r) 172 { 173 if (regs == NULL) 174 return 0; 175 176 memcpy(r, regs->fr, sizeof *r); 177 return 1; 178 } 179 180 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r) 181 { 182 memcpy(r, tsk->thread.regs.fr, sizeof(*r)); 183 return 1; 184 } 185 186 /* 187 * Copy architecture-specific thread state 188 */ 189 int 190 copy_thread(unsigned long clone_flags, unsigned long usp, 191 unsigned long kthread_arg, struct task_struct *p) 192 { 193 struct pt_regs *cregs = &(p->thread.regs); 194 void *stack = task_stack_page(p); 195 196 /* We have to use void * instead of a function pointer, because 197 * function pointers aren't a pointer to the function on 64-bit. 198 * Make them const so the compiler knows they live in .text */ 199 extern void * const ret_from_kernel_thread; 200 extern void * const child_return; 201 202 if (unlikely(p->flags & PF_KTHREAD)) { 203 /* kernel thread */ 204 memset(cregs, 0, sizeof(struct pt_regs)); 205 if (!usp) /* idle thread */ 206 return 0; 207 /* Must exit via ret_from_kernel_thread in order 208 * to call schedule_tail() 209 */ 210 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; 211 cregs->kpc = (unsigned long) &ret_from_kernel_thread; 212 /* 213 * Copy function and argument to be called from 214 * ret_from_kernel_thread. 215 */ 216 #ifdef CONFIG_64BIT 217 cregs->gr[27] = ((unsigned long *)usp)[3]; 218 cregs->gr[26] = ((unsigned long *)usp)[2]; 219 #else 220 cregs->gr[26] = usp; 221 #endif 222 cregs->gr[25] = kthread_arg; 223 } else { 224 /* user thread */ 225 /* usp must be word aligned. This also prevents users from 226 * passing in the value 1 (which is the signal for a special 227 * return for a kernel thread) */ 228 if (usp) { 229 usp = ALIGN(usp, 4); 230 if (likely(usp)) 231 cregs->gr[30] = usp; 232 } 233 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; 234 cregs->kpc = (unsigned long) &child_return; 235 236 /* Setup thread TLS area from the 4th parameter in clone */ 237 if (clone_flags & CLONE_SETTLS) 238 cregs->cr27 = cregs->gr[23]; 239 } 240 241 return 0; 242 } 243 244 unsigned long 245 get_wchan(struct task_struct *p) 246 { 247 struct unwind_frame_info info; 248 unsigned long ip; 249 int count = 0; 250 251 if (!p || p == current || p->state == TASK_RUNNING) 252 return 0; 253 254 /* 255 * These bracket the sleeping functions.. 256 */ 257 258 unwind_frame_init_from_blocked_task(&info, p); 259 do { 260 if (unwind_once(&info) < 0) 261 return 0; 262 ip = info.ip; 263 if (!in_sched_functions(ip)) 264 return ip; 265 } while (count++ < 16); 266 return 0; 267 } 268 269 #ifdef CONFIG_64BIT 270 void *dereference_function_descriptor(void *ptr) 271 { 272 Elf64_Fdesc *desc = ptr; 273 void *p; 274 275 if (!probe_kernel_address(&desc->addr, p)) 276 ptr = p; 277 return ptr; 278 } 279 #endif 280 281 static inline unsigned long brk_rnd(void) 282 { 283 return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT; 284 } 285 286 unsigned long arch_randomize_brk(struct mm_struct *mm) 287 { 288 unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd()); 289 290 if (ret < mm->brk) 291 return mm->brk; 292 return ret; 293 } 294