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/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 #include <linux/random.h> 53 54 #include <asm/io.h> 55 #include <asm/asm-offsets.h> 56 #include <asm/assembly.h> 57 #include <asm/pdc.h> 58 #include <asm/pdc_chassis.h> 59 #include <asm/pgalloc.h> 60 #include <asm/unwind.h> 61 #include <asm/sections.h> 62 63 #define COMMAND_GLOBAL F_EXTEND(0xfffe0030) 64 #define CMD_RESET 5 /* reset any module */ 65 66 /* 67 ** The Wright Brothers and Gecko systems have a H/W problem 68 ** (Lasi...'nuf said) may cause a broadcast reset to lockup 69 ** the system. An HVERSION dependent PDC call was developed 70 ** to perform a "safe", platform specific broadcast reset instead 71 ** of kludging up all the code. 72 ** 73 ** Older machines which do not implement PDC_BROADCAST_RESET will 74 ** return (with an error) and the regular broadcast reset can be 75 ** issued. Obviously, if the PDC does implement PDC_BROADCAST_RESET 76 ** the PDC call will not return (the system will be reset). 77 */ 78 void machine_restart(char *cmd) 79 { 80 #ifdef FASTBOOT_SELFTEST_SUPPORT 81 /* 82 ** If user has modified the Firmware Selftest Bitmap, 83 ** run the tests specified in the bitmap after the 84 ** system is rebooted w/PDC_DO_RESET. 85 ** 86 ** ftc_bitmap = 0x1AUL "Skip destructive memory tests" 87 ** 88 ** Using "directed resets" at each processor with the MEM_TOC 89 ** vector cleared will also avoid running destructive 90 ** memory self tests. (Not implemented yet) 91 */ 92 if (ftc_bitmap) { 93 pdc_do_firm_test_reset(ftc_bitmap); 94 } 95 #endif 96 /* set up a new led state on systems shipped with a LED State panel */ 97 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 98 99 /* "Normal" system reset */ 100 pdc_do_reset(); 101 102 /* Nope...box should reset with just CMD_RESET now */ 103 gsc_writel(CMD_RESET, COMMAND_GLOBAL); 104 105 /* Wait for RESET to lay us to rest. */ 106 while (1) ; 107 108 } 109 110 void machine_halt(void) 111 { 112 /* 113 ** The LED/ChassisCodes are updated by the led_halt() 114 ** function, called by the reboot notifier chain. 115 */ 116 } 117 118 void (*chassis_power_off)(void); 119 120 /* 121 * This routine is called from sys_reboot to actually turn off the 122 * machine 123 */ 124 void machine_power_off(void) 125 { 126 /* If there is a registered power off handler, call it. */ 127 if (chassis_power_off) 128 chassis_power_off(); 129 130 /* Put the soft power button back under hardware control. 131 * If the user had already pressed the power button, the 132 * following call will immediately power off. */ 133 pdc_soft_power_button(0); 134 135 pdc_chassis_send_status(PDC_CHASSIS_DIRECT_SHUTDOWN); 136 137 /* It seems we have no way to power the system off via 138 * software. The user has to press the button himself. */ 139 140 printk(KERN_EMERG "System shut down completed.\n" 141 "Please power this system off now."); 142 } 143 144 void (*pm_power_off)(void) = machine_power_off; 145 EXPORT_SYMBOL(pm_power_off); 146 147 void flush_thread(void) 148 { 149 /* Only needs to handle fpu stuff or perf monitors. 150 ** REVISIT: several arches implement a "lazy fpu state". 151 */ 152 } 153 154 void release_thread(struct task_struct *dead_task) 155 { 156 } 157 158 /* 159 * Fill in the FPU structure for a core dump. 160 */ 161 162 int dump_fpu (struct pt_regs * regs, elf_fpregset_t *r) 163 { 164 if (regs == NULL) 165 return 0; 166 167 memcpy(r, regs->fr, sizeof *r); 168 return 1; 169 } 170 171 int dump_task_fpu (struct task_struct *tsk, elf_fpregset_t *r) 172 { 173 memcpy(r, tsk->thread.regs.fr, sizeof(*r)); 174 return 1; 175 } 176 177 /* 178 * Copy architecture-specific thread state 179 */ 180 int 181 copy_thread(unsigned long clone_flags, unsigned long usp, 182 unsigned long kthread_arg, struct task_struct *p) 183 { 184 struct pt_regs *cregs = &(p->thread.regs); 185 void *stack = task_stack_page(p); 186 187 /* We have to use void * instead of a function pointer, because 188 * function pointers aren't a pointer to the function on 64-bit. 189 * Make them const so the compiler knows they live in .text */ 190 extern void * const ret_from_kernel_thread; 191 extern void * const child_return; 192 193 if (unlikely(p->flags & PF_KTHREAD)) { 194 /* kernel thread */ 195 memset(cregs, 0, sizeof(struct pt_regs)); 196 if (!usp) /* idle thread */ 197 return 0; 198 /* Must exit via ret_from_kernel_thread in order 199 * to call schedule_tail() 200 */ 201 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; 202 cregs->kpc = (unsigned long) &ret_from_kernel_thread; 203 /* 204 * Copy function and argument to be called from 205 * ret_from_kernel_thread. 206 */ 207 #ifdef CONFIG_64BIT 208 cregs->gr[27] = ((unsigned long *)usp)[3]; 209 cregs->gr[26] = ((unsigned long *)usp)[2]; 210 #else 211 cregs->gr[26] = usp; 212 #endif 213 cregs->gr[25] = kthread_arg; 214 } else { 215 /* user thread */ 216 /* usp must be word aligned. This also prevents users from 217 * passing in the value 1 (which is the signal for a special 218 * return for a kernel thread) */ 219 if (usp) { 220 usp = ALIGN(usp, 4); 221 if (likely(usp)) 222 cregs->gr[30] = usp; 223 } 224 cregs->ksp = (unsigned long)stack + THREAD_SZ_ALGN + FRAME_SIZE; 225 cregs->kpc = (unsigned long) &child_return; 226 227 /* Setup thread TLS area from the 4th parameter in clone */ 228 if (clone_flags & CLONE_SETTLS) 229 cregs->cr27 = cregs->gr[23]; 230 } 231 232 return 0; 233 } 234 235 unsigned long thread_saved_pc(struct task_struct *t) 236 { 237 return t->thread.regs.kpc; 238 } 239 240 unsigned long 241 get_wchan(struct task_struct *p) 242 { 243 struct unwind_frame_info info; 244 unsigned long ip; 245 int count = 0; 246 247 if (!p || p == current || p->state == TASK_RUNNING) 248 return 0; 249 250 /* 251 * These bracket the sleeping functions.. 252 */ 253 254 unwind_frame_init_from_blocked_task(&info, p); 255 do { 256 if (unwind_once(&info) < 0) 257 return 0; 258 ip = info.ip; 259 if (!in_sched_functions(ip)) 260 return ip; 261 } while (count++ < 16); 262 return 0; 263 } 264 265 #ifdef CONFIG_64BIT 266 void *dereference_function_descriptor(void *ptr) 267 { 268 Elf64_Fdesc *desc = ptr; 269 void *p; 270 271 if (!probe_kernel_address(&desc->addr, p)) 272 ptr = p; 273 return ptr; 274 } 275 #endif 276 277 static inline unsigned long brk_rnd(void) 278 { 279 /* 8MB for 32bit, 1GB for 64bit */ 280 if (is_32bit_task()) 281 return (get_random_int() & 0x7ffUL) << PAGE_SHIFT; 282 else 283 return (get_random_int() & 0x3ffffUL) << 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