Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 1 | /* |
| 2 | * linux/arch/arm/kernel/process.c |
| 3 | * |
| 4 | * Copyright (C) 1996-2000 Russell King - Converted to ARM. |
| 5 | * Original Copyright (C) 1995 Linus Torvalds |
| 6 | * |
| 7 | * This program is free software; you can redistribute it and/or modify |
| 8 | * it under the terms of the GNU General Public License version 2 as |
| 9 | * published by the Free Software Foundation. |
| 10 | */ |
| 11 | #include <stdarg.h> |
| 12 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 13 | #include <linux/module.h> |
| 14 | #include <linux/sched.h> |
| 15 | #include <linux/kernel.h> |
| 16 | #include <linux/mm.h> |
| 17 | #include <linux/stddef.h> |
| 18 | #include <linux/unistd.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 19 | #include <linux/slab.h> |
| 20 | #include <linux/user.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 21 | #include <linux/delay.h> |
| 22 | #include <linux/reboot.h> |
| 23 | #include <linux/interrupt.h> |
| 24 | #include <linux/kallsyms.h> |
| 25 | #include <linux/init.h> |
Russell King | a054a81 | 2005-11-02 22:24:33 +0000 | [diff] [blame] | 26 | #include <linux/cpu.h> |
Ben Dooks | 84dff1a | 2006-03-15 23:17:23 +0000 | [diff] [blame] | 27 | #include <linux/elfcore.h> |
Richard Purdie | 74617fb | 2006-06-19 19:57:12 +0100 | [diff] [blame] | 28 | #include <linux/pm.h> |
Kevin Hilman | 9e4559d | 2007-03-14 17:33:24 +0100 | [diff] [blame] | 29 | #include <linux/tick.h> |
Russell King | 154c772 | 2007-06-18 14:59:45 +0100 | [diff] [blame] | 30 | #include <linux/utsname.h> |
Russell King | 33fa9b1 | 2008-09-06 11:35:55 +0100 | [diff] [blame] | 31 | #include <linux/uaccess.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 32 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 33 | #include <asm/leds.h> |
| 34 | #include <asm/processor.h> |
Russell King | 78ff18a | 2006-01-03 17:39:34 +0000 | [diff] [blame] | 35 | #include <asm/system.h> |
Russell King | d6551e8 | 2006-06-21 13:31:52 +0100 | [diff] [blame] | 36 | #include <asm/thread_notify.h> |
Catalin Marinas | 2d7c11b | 2009-02-11 13:07:53 +0100 | [diff] [blame^] | 37 | #include <asm/stacktrace.h> |
Russell King | 2ea8339 | 2005-06-27 14:04:05 +0100 | [diff] [blame] | 38 | #include <asm/mach/time.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 39 | |
Russell King | ae0a846 | 2007-01-09 12:57:37 +0000 | [diff] [blame] | 40 | static const char *processor_modes[] = { |
| 41 | "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" , |
| 42 | "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26", |
| 43 | "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" , |
| 44 | "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32" |
| 45 | }; |
| 46 | |
George G. Davis | 909d6c6 | 2007-06-26 01:38:27 +0100 | [diff] [blame] | 47 | static const char *isa_modes[] = { |
| 48 | "ARM" , "Thumb" , "Jazelle", "ThumbEE" |
| 49 | }; |
| 50 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 51 | extern void setup_mm_for_reboot(char mode); |
| 52 | |
| 53 | static volatile int hlt_counter; |
| 54 | |
Russell King | a09e64f | 2008-08-05 16:14:15 +0100 | [diff] [blame] | 55 | #include <mach/system.h> |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 56 | |
| 57 | void disable_hlt(void) |
| 58 | { |
| 59 | hlt_counter++; |
| 60 | } |
| 61 | |
| 62 | EXPORT_SYMBOL(disable_hlt); |
| 63 | |
| 64 | void enable_hlt(void) |
| 65 | { |
| 66 | hlt_counter--; |
| 67 | } |
| 68 | |
| 69 | EXPORT_SYMBOL(enable_hlt); |
| 70 | |
| 71 | static int __init nohlt_setup(char *__unused) |
| 72 | { |
| 73 | hlt_counter = 1; |
| 74 | return 1; |
| 75 | } |
| 76 | |
| 77 | static int __init hlt_setup(char *__unused) |
| 78 | { |
| 79 | hlt_counter = 0; |
| 80 | return 1; |
| 81 | } |
| 82 | |
| 83 | __setup("nohlt", nohlt_setup); |
| 84 | __setup("hlt", hlt_setup); |
| 85 | |
Richard Purdie | 74617fb | 2006-06-19 19:57:12 +0100 | [diff] [blame] | 86 | void arm_machine_restart(char mode) |
| 87 | { |
| 88 | /* |
| 89 | * Clean and disable cache, and turn off interrupts |
| 90 | */ |
| 91 | cpu_proc_fin(); |
| 92 | |
| 93 | /* |
| 94 | * Tell the mm system that we are going to reboot - |
| 95 | * we may need it to insert some 1:1 mappings so that |
| 96 | * soft boot works. |
| 97 | */ |
| 98 | setup_mm_for_reboot(mode); |
| 99 | |
| 100 | /* |
| 101 | * Now call the architecture specific reboot code. |
| 102 | */ |
| 103 | arch_reset(mode); |
| 104 | |
| 105 | /* |
| 106 | * Whoops - the architecture was unable to reboot. |
| 107 | * Tell the user! |
| 108 | */ |
| 109 | mdelay(1000); |
| 110 | printk("Reboot failed -- System halted\n"); |
| 111 | while (1); |
| 112 | } |
| 113 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 114 | /* |
Richard Purdie | 74617fb | 2006-06-19 19:57:12 +0100 | [diff] [blame] | 115 | * Function pointers to optional machine specific functions |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 116 | */ |
| 117 | void (*pm_idle)(void); |
| 118 | EXPORT_SYMBOL(pm_idle); |
| 119 | |
| 120 | void (*pm_power_off)(void); |
| 121 | EXPORT_SYMBOL(pm_power_off); |
| 122 | |
Richard Purdie | 74617fb | 2006-06-19 19:57:12 +0100 | [diff] [blame] | 123 | void (*arm_pm_restart)(char str) = arm_machine_restart; |
| 124 | EXPORT_SYMBOL_GPL(arm_pm_restart); |
| 125 | |
| 126 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 127 | /* |
| 128 | * This is our default idle handler. We need to disable |
| 129 | * interrupts here to ensure we don't miss a wakeup call. |
| 130 | */ |
Ben Dooks | 84dff1a | 2006-03-15 23:17:23 +0000 | [diff] [blame] | 131 | static void default_idle(void) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 132 | { |
Nick Piggin | 64c7c8f | 2005-11-08 21:39:04 -0800 | [diff] [blame] | 133 | if (hlt_counter) |
| 134 | cpu_relax(); |
| 135 | else { |
| 136 | local_irq_disable(); |
Russell King | 205bee6 | 2008-04-20 13:57:26 +0100 | [diff] [blame] | 137 | if (!need_resched()) |
Nick Piggin | 64c7c8f | 2005-11-08 21:39:04 -0800 | [diff] [blame] | 138 | arch_idle(); |
Nick Piggin | 64c7c8f | 2005-11-08 21:39:04 -0800 | [diff] [blame] | 139 | local_irq_enable(); |
Russell King | 2ea8339 | 2005-06-27 14:04:05 +0100 | [diff] [blame] | 140 | } |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 141 | } |
| 142 | |
| 143 | /* |
| 144 | * The idle thread. We try to conserve power, while trying to keep |
| 145 | * overall latency low. The architecture specific idle is passed |
| 146 | * a value to indicate the level of "idleness" of the system. |
| 147 | */ |
| 148 | void cpu_idle(void) |
| 149 | { |
| 150 | local_fiq_enable(); |
| 151 | |
| 152 | /* endless idle loop with no priority at all */ |
| 153 | while (1) { |
| 154 | void (*idle)(void) = pm_idle; |
Russell King | a054a81 | 2005-11-02 22:24:33 +0000 | [diff] [blame] | 155 | |
| 156 | #ifdef CONFIG_HOTPLUG_CPU |
| 157 | if (cpu_is_offline(smp_processor_id())) { |
| 158 | leds_event(led_idle_start); |
| 159 | cpu_die(); |
| 160 | } |
| 161 | #endif |
| 162 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 163 | if (!idle) |
| 164 | idle = default_idle; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 165 | leds_event(led_idle_start); |
Thomas Gleixner | b8f8c3c | 2008-07-18 17:27:28 +0200 | [diff] [blame] | 166 | tick_nohz_stop_sched_tick(1); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 167 | while (!need_resched()) |
| 168 | idle(); |
| 169 | leds_event(led_idle_end); |
Kevin Hilman | 9e4559d | 2007-03-14 17:33:24 +0100 | [diff] [blame] | 170 | tick_nohz_restart_sched_tick(); |
Nick Piggin | 5bfb5d6 | 2005-11-08 21:39:01 -0800 | [diff] [blame] | 171 | preempt_enable_no_resched(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 172 | schedule(); |
Nick Piggin | 5bfb5d6 | 2005-11-08 21:39:01 -0800 | [diff] [blame] | 173 | preempt_disable(); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 174 | } |
| 175 | } |
| 176 | |
| 177 | static char reboot_mode = 'h'; |
| 178 | |
| 179 | int __init reboot_setup(char *str) |
| 180 | { |
| 181 | reboot_mode = str[0]; |
| 182 | return 1; |
| 183 | } |
| 184 | |
| 185 | __setup("reboot=", reboot_setup); |
| 186 | |
| 187 | void machine_halt(void) |
| 188 | { |
| 189 | } |
| 190 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 191 | |
| 192 | void machine_power_off(void) |
| 193 | { |
| 194 | if (pm_power_off) |
| 195 | pm_power_off(); |
| 196 | } |
| 197 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 198 | void machine_restart(char * __unused) |
| 199 | { |
Richard Purdie | 74617fb | 2006-06-19 19:57:12 +0100 | [diff] [blame] | 200 | arm_pm_restart(reboot_mode); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 201 | } |
| 202 | |
Russell King | 652a12e | 2005-04-17 15:50:36 +0100 | [diff] [blame] | 203 | void __show_regs(struct pt_regs *regs) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 204 | { |
Russell King | 154c772 | 2007-06-18 14:59:45 +0100 | [diff] [blame] | 205 | unsigned long flags; |
| 206 | char buf[64]; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 207 | |
Russell King | 154c772 | 2007-06-18 14:59:45 +0100 | [diff] [blame] | 208 | printk("CPU: %d %s (%s %.*s)\n", |
| 209 | smp_processor_id(), print_tainted(), init_utsname()->release, |
| 210 | (int)strcspn(init_utsname()->version, " "), |
| 211 | init_utsname()->version); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 212 | print_symbol("PC is at %s\n", instruction_pointer(regs)); |
| 213 | print_symbol("LR is at %s\n", regs->ARM_lr); |
Russell King | 154c772 | 2007-06-18 14:59:45 +0100 | [diff] [blame] | 214 | printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n" |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 215 | "sp : %08lx ip : %08lx fp : %08lx\n", |
Russell King | 154c772 | 2007-06-18 14:59:45 +0100 | [diff] [blame] | 216 | regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr, |
| 217 | regs->ARM_sp, regs->ARM_ip, regs->ARM_fp); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 218 | printk("r10: %08lx r9 : %08lx r8 : %08lx\n", |
| 219 | regs->ARM_r10, regs->ARM_r9, |
| 220 | regs->ARM_r8); |
| 221 | printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", |
| 222 | regs->ARM_r7, regs->ARM_r6, |
| 223 | regs->ARM_r5, regs->ARM_r4); |
| 224 | printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", |
| 225 | regs->ARM_r3, regs->ARM_r2, |
| 226 | regs->ARM_r1, regs->ARM_r0); |
Russell King | 154c772 | 2007-06-18 14:59:45 +0100 | [diff] [blame] | 227 | |
| 228 | flags = regs->ARM_cpsr; |
| 229 | buf[0] = flags & PSR_N_BIT ? 'N' : 'n'; |
| 230 | buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z'; |
| 231 | buf[2] = flags & PSR_C_BIT ? 'C' : 'c'; |
| 232 | buf[3] = flags & PSR_V_BIT ? 'V' : 'v'; |
| 233 | buf[4] = '\0'; |
| 234 | |
George G. Davis | 909d6c6 | 2007-06-26 01:38:27 +0100 | [diff] [blame] | 235 | printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n", |
Russell King | 154c772 | 2007-06-18 14:59:45 +0100 | [diff] [blame] | 236 | buf, interrupts_enabled(regs) ? "n" : "ff", |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 237 | fast_interrupts_enabled(regs) ? "n" : "ff", |
| 238 | processor_modes[processor_mode(regs)], |
George G. Davis | 909d6c6 | 2007-06-26 01:38:27 +0100 | [diff] [blame] | 239 | isa_modes[isa_mode(regs)], |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 240 | get_fs() == get_ds() ? "kernel" : "user"); |
Russell King | 154c772 | 2007-06-18 14:59:45 +0100 | [diff] [blame] | 241 | #ifdef CONFIG_CPU_CP15 |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 242 | { |
Hyok S. Choi | f12d0d7 | 2006-09-26 17:36:37 +0900 | [diff] [blame] | 243 | unsigned int ctrl; |
Russell King | 154c772 | 2007-06-18 14:59:45 +0100 | [diff] [blame] | 244 | |
| 245 | buf[0] = '\0'; |
Hyok S. Choi | f12d0d7 | 2006-09-26 17:36:37 +0900 | [diff] [blame] | 246 | #ifdef CONFIG_CPU_CP15_MMU |
Russell King | 154c772 | 2007-06-18 14:59:45 +0100 | [diff] [blame] | 247 | { |
| 248 | unsigned int transbase, dac; |
| 249 | asm("mrc p15, 0, %0, c2, c0\n\t" |
| 250 | "mrc p15, 0, %1, c3, c0\n" |
| 251 | : "=r" (transbase), "=r" (dac)); |
| 252 | snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x", |
| 253 | transbase, dac); |
| 254 | } |
Hyok S. Choi | f12d0d7 | 2006-09-26 17:36:37 +0900 | [diff] [blame] | 255 | #endif |
Russell King | 154c772 | 2007-06-18 14:59:45 +0100 | [diff] [blame] | 256 | asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl)); |
| 257 | |
| 258 | printk("Control: %08x%s\n", ctrl, buf); |
| 259 | } |
Hyok S. Choi | f12d0d7 | 2006-09-26 17:36:37 +0900 | [diff] [blame] | 260 | #endif |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 261 | } |
| 262 | |
Russell King | 652a12e | 2005-04-17 15:50:36 +0100 | [diff] [blame] | 263 | void show_regs(struct pt_regs * regs) |
| 264 | { |
| 265 | printk("\n"); |
Alexey Dobriyan | 19c5870 | 2007-10-18 23:40:41 -0700 | [diff] [blame] | 266 | printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm); |
Russell King | 652a12e | 2005-04-17 15:50:36 +0100 | [diff] [blame] | 267 | __show_regs(regs); |
| 268 | __backtrace(); |
| 269 | } |
| 270 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 271 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 272 | * Free current thread data structures etc.. |
| 273 | */ |
| 274 | void exit_thread(void) |
| 275 | { |
| 276 | } |
| 277 | |
Russell King | d6551e8 | 2006-06-21 13:31:52 +0100 | [diff] [blame] | 278 | ATOMIC_NOTIFIER_HEAD(thread_notify_head); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 279 | |
Russell King | d6551e8 | 2006-06-21 13:31:52 +0100 | [diff] [blame] | 280 | EXPORT_SYMBOL_GPL(thread_notify_head); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 281 | |
| 282 | void flush_thread(void) |
| 283 | { |
| 284 | struct thread_info *thread = current_thread_info(); |
| 285 | struct task_struct *tsk = current; |
| 286 | |
| 287 | memset(thread->used_cp, 0, sizeof(thread->used_cp)); |
| 288 | memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); |
Russell King | d6551e8 | 2006-06-21 13:31:52 +0100 | [diff] [blame] | 289 | memset(&thread->fpstate, 0, sizeof(union fp_state)); |
| 290 | |
| 291 | thread_notify(THREAD_NOTIFY_FLUSH, thread); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 292 | } |
| 293 | |
| 294 | void release_thread(struct task_struct *dead_task) |
| 295 | { |
Russell King | d6551e8 | 2006-06-21 13:31:52 +0100 | [diff] [blame] | 296 | struct thread_info *thread = task_thread_info(dead_task); |
| 297 | |
| 298 | thread_notify(THREAD_NOTIFY_RELEASE, thread); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 299 | } |
| 300 | |
| 301 | asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); |
| 302 | |
| 303 | int |
| 304 | copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, |
| 305 | unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) |
| 306 | { |
Al Viro | 815d5ec | 2006-01-12 01:05:57 -0800 | [diff] [blame] | 307 | struct thread_info *thread = task_thread_info(p); |
| 308 | struct pt_regs *childregs = task_pt_regs(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 309 | |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 310 | *childregs = *regs; |
| 311 | childregs->ARM_r0 = 0; |
| 312 | childregs->ARM_sp = stack_start; |
| 313 | |
| 314 | memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); |
| 315 | thread->cpu_context.sp = (unsigned long)childregs; |
| 316 | thread->cpu_context.pc = (unsigned long)ret_from_fork; |
| 317 | |
| 318 | if (clone_flags & CLONE_SETTLS) |
| 319 | thread->tp_value = regs->ARM_r3; |
| 320 | |
| 321 | return 0; |
| 322 | } |
| 323 | |
| 324 | /* |
| 325 | * fill in the fpe structure for a core dump... |
| 326 | */ |
| 327 | int dump_fpu (struct pt_regs *regs, struct user_fp *fp) |
| 328 | { |
| 329 | struct thread_info *thread = current_thread_info(); |
| 330 | int used_math = thread->used_cp[1] | thread->used_cp[2]; |
| 331 | |
| 332 | if (used_math) |
| 333 | memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); |
| 334 | |
| 335 | return used_math != 0; |
| 336 | } |
| 337 | EXPORT_SYMBOL(dump_fpu); |
| 338 | |
| 339 | /* |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 340 | * Shuffle the argument into the correct register before calling the |
| 341 | * thread function. r1 is the thread argument, r2 is the pointer to |
| 342 | * the thread function, and r3 points to the exit function. |
| 343 | */ |
| 344 | extern void kernel_thread_helper(void); |
| 345 | asm( ".section .text\n" |
| 346 | " .align\n" |
| 347 | " .type kernel_thread_helper, #function\n" |
| 348 | "kernel_thread_helper:\n" |
| 349 | " mov r0, r1\n" |
| 350 | " mov lr, r3\n" |
| 351 | " mov pc, r2\n" |
| 352 | " .size kernel_thread_helper, . - kernel_thread_helper\n" |
| 353 | " .previous"); |
| 354 | |
| 355 | /* |
| 356 | * Create a kernel thread. |
| 357 | */ |
| 358 | pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) |
| 359 | { |
| 360 | struct pt_regs regs; |
| 361 | |
| 362 | memset(®s, 0, sizeof(regs)); |
| 363 | |
| 364 | regs.ARM_r1 = (unsigned long)arg; |
| 365 | regs.ARM_r2 = (unsigned long)fn; |
| 366 | regs.ARM_r3 = (unsigned long)do_exit; |
| 367 | regs.ARM_pc = (unsigned long)kernel_thread_helper; |
| 368 | regs.ARM_cpsr = SVC_MODE; |
| 369 | |
| 370 | return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); |
| 371 | } |
| 372 | EXPORT_SYMBOL(kernel_thread); |
| 373 | |
| 374 | unsigned long get_wchan(struct task_struct *p) |
| 375 | { |
Catalin Marinas | 2d7c11b | 2009-02-11 13:07:53 +0100 | [diff] [blame^] | 376 | struct stackframe frame; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 377 | int count = 0; |
| 378 | if (!p || p == current || p->state == TASK_RUNNING) |
| 379 | return 0; |
| 380 | |
Catalin Marinas | 2d7c11b | 2009-02-11 13:07:53 +0100 | [diff] [blame^] | 381 | frame.fp = thread_saved_fp(p); |
| 382 | frame.sp = thread_saved_sp(p); |
| 383 | frame.lr = 0; /* recovered from the stack */ |
| 384 | frame.pc = thread_saved_pc(p); |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 385 | do { |
Catalin Marinas | 2d7c11b | 2009-02-11 13:07:53 +0100 | [diff] [blame^] | 386 | int ret = unwind_frame(&frame); |
| 387 | if (ret < 0) |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 388 | return 0; |
Catalin Marinas | 2d7c11b | 2009-02-11 13:07:53 +0100 | [diff] [blame^] | 389 | if (!in_sched_functions(frame.pc)) |
| 390 | return frame.pc; |
Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 391 | } while (count ++ < 16); |
| 392 | return 0; |
| 393 | } |