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 57 #include <asm/io.h> 58 #include <asm/asm-offsets.h> 59 #include <asm/assembly.h> 60 #include <asm/pdc.h> 61 #include <asm/pdc_chassis.h> 62 #include <asm/pgalloc.h> 63 #include <asm/unwind.h> 64 #include <asm/sections.h> 65 66 #define COMMAND_GLOBAL F_EXTEND(0xfffe0030) 67 #define CMD_RESET 5 /* reset any module */ 68 69 /* 70 ** The Wright Brothers and Gecko systems have a H/W problem 71 ** (Lasi...'nuf said) may cause a broadcast reset to lockup 72 ** the system. An HVERSION dependent PDC call was developed 73 ** to perform a "safe", platform specific broadcast reset instead 74 ** of kludging up all the code. 75 ** 76 ** Older machines which do not implement PDC_BROADCAST_RESET will 77 ** return (with an error) and the regular broadcast reset can be 78 ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET 79 ** the PDC call will not return (the system will be reset). 80 */ 81 void machine_restart(char *cmd) 82 { 83 #ifdef FASTBOOT_SELFTEST_SUPPORT 84 /* 85 ** If user has modified the Firmware Selftest Bitmap, 86 ** run the tests specified in the bitmap after the 87 ** system is rebooted w/PDC_DO_RESET. 88 ** 89 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests" 90 ** 91 ** Using "directed resets" at each processor with the MEM_TOC 92 ** vector cleared will also avoid running destructive 93 ** memory self tests. (Not implemented yet) 94 */ 95 if (ftc_bitmap) { 96 pdc_do_firm_test_reset(ftc_bitmap); 97 } 98 #endif 99 /* set up a new led state on systems shipped with a LED State panel */ 100 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 101 102 /* "Normal" system reset */ 103 pdc_do_reset(); 104 105 /* Nope...box should reset with just CMD_RESET now */ 106 gsc_writel(CMD_RESET, COMMAND_GLOBAL); 107 108 /* Wait for RESET to lay us to rest. */ 109 while (1) ; 110 111 } 112 113 void machine_halt(void) 114 { 115 /* 116 ** The LED/ChassisCodes are updated by the led_halt() 117 ** function, called by the reboot notifier chain. 118 */ 119 } 120 121 void (*chassis_power_off)(void); 122 123 /* 124 * This routine is called from sys_reboot to actually turn off the 125 * machine 126 */ 127 void machine_power_off(void) 128 { 129 /* If there is a registered power off handler, call it. */ 130 if (chassis_power_off) 131 chassis_power_off(); 132 133 /* Put the soft power button back under hardware control. 134 * If the user had already pressed the power button, the 135 * following call will immediately power off. */ 136 pdc_soft_power_button(0); 137 138 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 139 140 /* It seems we have no way to power the system off via 141 * software. The user has to press the button himself. */ 142 143 printk(KERN_EMERG "System shut down completed.\n" 144 "Please power this system off now."); 145 146 /* prevent soft lockup/stalled CPU messages for endless loop. */ 147 rcu_sysrq_start(); 148 for (;;); 149 } 150 151 void (*pm_power_off)(void) = machine_power_off; 152 EXPORT_SYMBOL(pm_power_off); 153 154 void flush_thread(void) 155 { 156 /* Only needs to handle fpu stuff or perf monitors. 157 ** REVISIT: several arches implement a "lazy fpu state". 158 */ 159 } 160 161 void release_thread(struct task_struct *dead_task) 162 { 163 } 164 165 /* 166 * Fill in the FPU structure for a core dump. 167 */ 168 169 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r) 170 { 171 if (regs == NULL) 172 return 0; 173 174 memcpy(r, regs->fr, sizeof *r); 175 return 1; 176 } 177 178 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r) 179 { 180 memcpy(r, tsk->thread.regs.fr, sizeof(*r)); 181 return 1; 182 } 183 184 /* 185 * Copy architecture-specific thread state 186 */ 187 int 188 copy_thread(unsigned long clone_flags, unsigned long usp, 189 unsigned long kthread_arg, struct task_struct *p) 190 { 191 struct pt_regs *cregs = &(p->thread.regs); 192 void *stack = task_stack_page(p); 193 194 /* We have to use void * instead of a function pointer, because 195 * function pointers aren't a pointer to the function on 64-bit. 196 * Make them const so the compiler knows they live in .text */ 197 extern void * const ret_from_kernel_thread; 198 extern void * const child_return; 199 200 if (unlikely(p->flags & PF_KTHREAD)) { 201 /* kernel thread */ 202 memset(cregs, 0, sizeof(struct pt_regs)); 203 if (!usp) /* idle thread */ 204 return 0; 205 /* Must exit via ret_from_kernel_thread in order 206 * to call schedule_tail() 207 */ 208 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; 209 cregs->kpc = (unsigned long) &ret_from_kernel_thread; 210 /* 211 * Copy function and argument to be called from 212 * ret_from_kernel_thread. 213 */ 214 #ifdef CONFIG_64BIT 215 cregs->gr[27] = ((unsigned long *)usp)[3]; 216 cregs->gr[26] = ((unsigned long *)usp)[2]; 217 #else 218 cregs->gr[26] = usp; 219 #endif 220 cregs->gr[25] = kthread_arg; 221 } else { 222 /* user thread */ 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 if (usp) { 227 usp = ALIGN(usp, 4); 228 if (likely(usp)) 229 cregs->gr[30] = usp; 230 } 231 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; 232 cregs->kpc = (unsigned long) &child_return; 233 234 /* Setup thread TLS area from the 4th parameter in clone */ 235 if (clone_flags & CLONE_SETTLS) 236 cregs->cr27 = cregs->gr[23]; 237 } 238 239 return 0; 240 } 241 242 unsigned long thread_saved_pc(struct task_struct *t) 243 { 244 return t->thread.regs.kpc; 245 } 246 247 unsigned long 248 get_wchan(struct task_struct *p) 249 { 250 struct unwind_frame_info info; 251 unsigned long ip; 252 int count = 0; 253 254 if (!p || p == current || p->state == TASK_RUNNING) 255 return 0; 256 257 /* 258 * These bracket the sleeping functions.. 259 */ 260 261 unwind_frame_init_from_blocked_task(&info, p); 262 do { 263 if (unwind_once(&info) < 0) 264 return 0; 265 ip = info.ip; 266 if (!in_sched_functions(ip)) 267 return ip; 268 } while (count++ < 16); 269 return 0; 270 } 271 272 #ifdef CONFIG_64BIT 273 void *dereference_function_descriptor(void *ptr) 274 { 275 Elf64_Fdesc *desc = ptr; 276 void *p; 277 278 if (!probe_kernel_address(&desc->addr, p)) 279 ptr = p; 280 return ptr; 281 } 282 #endif 283 284 static inline unsigned long brk_rnd(void) 285 { 286 return (get_random_int() & BRK_RND_MASK) << PAGE_SHIFT; 287 } 288 289 unsigned long arch_randomize_brk(struct mm_struct *mm) 290 { 291 unsigned long ret = PAGE_ALIGN(mm->brk + brk_rnd()); 292 293 if (ret < mm->brk) 294 return mm->brk; 295 return ret; 296 } 297