blob: 1e8b3e2de7a3b0ead2cfd2aaa87de146d3fc8325 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Paul Gortmakerecea4ab2011-07-22 10:58:34 -040013#include <linux/export.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070014#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 Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/user.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/delay.h>
21#include <linux/reboot.h>
22#include <linux/interrupt.h>
23#include <linux/kallsyms.h>
24#include <linux/init.h>
Russell Kinga054a812005-11-02 22:24:33 +000025#include <linux/cpu.h>
Ben Dooks84dff1a2006-03-15 23:17:23 +000026#include <linux/elfcore.h>
Richard Purdie74617fb2006-06-19 19:57:12 +010027#include <linux/pm.h>
Kevin Hilman9e4559d2007-03-14 17:33:24 +010028#include <linux/tick.h>
Russell King154c7722007-06-18 14:59:45 +010029#include <linux/utsname.h>
Russell King33fa9b12008-09-06 11:35:55 +010030#include <linux/uaccess.h>
Nicolas Pitre990cb8a2010-06-14 16:27:19 -040031#include <linux/random.h>
Will Deacon864232f2010-09-03 10:42:55 +010032#include <linux/hw_breakpoint.h>
Len Browna0bfa132011-04-01 19:34:59 -040033#include <linux/cpuidle.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070034
Russell King9ca03a22010-07-26 12:22:12 +010035#include <asm/cacheflush.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070036#include <asm/leds.h>
37#include <asm/processor.h>
Russell King78ff18a2006-01-03 17:39:34 +000038#include <asm/system.h>
Russell Kingd6551e82006-06-21 13:31:52 +010039#include <asm/thread_notify.h>
Catalin Marinas2d7c11b2009-02-11 13:07:53 +010040#include <asm/stacktrace.h>
Russell King2ea83392005-06-27 14:04:05 +010041#include <asm/mach/time.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070042
Nicolas Pitrec743f382010-05-24 23:55:42 -040043#ifdef CONFIG_CC_STACKPROTECTOR
44#include <linux/stackprotector.h>
45unsigned long __stack_chk_guard __read_mostly;
46EXPORT_SYMBOL(__stack_chk_guard);
47#endif
48
Russell Kingae0a8462007-01-09 12:57:37 +000049static const char *processor_modes[] = {
50 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
51 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
52 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
53 "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
54};
55
George G. Davis909d6c62007-06-26 01:38:27 +010056static const char *isa_modes[] = {
57 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
58};
59
Russell King5aafec12011-11-01 10:15:27 +000060extern void setup_mm_for_reboot(void);
Linus Torvalds1da177e2005-04-16 15:20:36 -070061
62static volatile int hlt_counter;
63
Russell Kinga09e64f2008-08-05 16:14:15 +010064#include <mach/system.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070065
66void disable_hlt(void)
67{
68 hlt_counter++;
69}
70
71EXPORT_SYMBOL(disable_hlt);
72
73void enable_hlt(void)
74{
75 hlt_counter--;
76}
77
78EXPORT_SYMBOL(enable_hlt);
79
80static int __init nohlt_setup(char *__unused)
81{
82 hlt_counter = 1;
83 return 1;
84}
85
86static int __init hlt_setup(char *__unused)
87{
88 hlt_counter = 0;
89 return 1;
90}
91
92__setup("nohlt", nohlt_setup);
93__setup("hlt", hlt_setup);
94
Russell Kinge879c862011-11-01 13:16:26 +000095void soft_restart(unsigned long addr)
Richard Purdie74617fb2006-06-19 19:57:12 +010096{
Russell King9ca03a22010-07-26 12:22:12 +010097 /* Disable interrupts first */
98 local_irq_disable();
99 local_fiq_disable();
Richard Purdie74617fb2006-06-19 19:57:12 +0100100
101 /*
102 * Tell the mm system that we are going to reboot -
103 * we may need it to insert some 1:1 mappings so that
104 * soft boot works.
105 */
Russell King5aafec12011-11-01 10:15:27 +0000106 setup_mm_for_reboot();
Richard Purdie74617fb2006-06-19 19:57:12 +0100107
Russell King9ca03a22010-07-26 12:22:12 +0100108 /* Clean and invalidate caches */
109 flush_cache_all();
110
111 /* Turn off caching */
112 cpu_proc_fin();
113
114 /* Push out any further dirty data, and ensure cache is empty */
115 flush_cache_all();
116
Russell Kinge879c862011-11-01 13:16:26 +0000117 cpu_reset(addr);
118}
119
120void arm_machine_restart(char mode, const char *cmd)
121{
122 /* Disable interrupts first */
123 local_irq_disable();
124 local_fiq_disable();
125
126 /* Call the architecture specific reboot code. */
Russell Kingbe093be2009-03-19 16:20:24 +0000127 arch_reset(mode, cmd);
Richard Purdie74617fb2006-06-19 19:57:12 +0100128}
129
Linus Torvalds1da177e2005-04-16 15:20:36 -0700130/*
Richard Purdie74617fb2006-06-19 19:57:12 +0100131 * Function pointers to optional machine specific functions
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133void (*pm_power_off)(void);
134EXPORT_SYMBOL(pm_power_off);
135
Russell Kingbe093be2009-03-19 16:20:24 +0000136void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart;
Richard Purdie74617fb2006-06-19 19:57:12 +0100137EXPORT_SYMBOL_GPL(arm_pm_restart);
138
Kevin Hilmanc7b0aff2010-10-01 22:13:47 +0100139static void do_nothing(void *unused)
140{
141}
142
143/*
144 * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
145 * pm_idle and update to new pm_idle value. Required while changing pm_idle
146 * handler on SMP systems.
147 *
148 * Caller must have changed pm_idle to the new value before the call. Old
149 * pm_idle value will not be used by any CPU after the return of this function.
150 */
151void cpu_idle_wait(void)
152{
153 smp_mb();
154 /* kick all the CPUs so that they exit out of pm_idle */
155 smp_call_function(do_nothing, NULL, 1);
156}
157EXPORT_SYMBOL_GPL(cpu_idle_wait);
Richard Purdie74617fb2006-06-19 19:57:12 +0100158
Linus Torvalds1da177e2005-04-16 15:20:36 -0700159/*
160 * This is our default idle handler. We need to disable
161 * interrupts here to ensure we don't miss a wakeup call.
162 */
Ben Dooks84dff1a2006-03-15 23:17:23 +0000163static void default_idle(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700164{
Russell King9ccdac32009-06-22 22:34:55 +0100165 if (!need_resched())
166 arch_idle();
167 local_irq_enable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700168}
169
Russell King9ccdac32009-06-22 22:34:55 +0100170void (*pm_idle)(void) = default_idle;
171EXPORT_SYMBOL(pm_idle);
172
Linus Torvalds1da177e2005-04-16 15:20:36 -0700173/*
Russell King9ccdac32009-06-22 22:34:55 +0100174 * The idle thread, has rather strange semantics for calling pm_idle,
175 * but this is what x86 does and we need to do the same, so that
176 * things like cpuidle get called in the same way. The only difference
177 * is that we always respect 'hlt_counter' to prevent low power idle.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 */
179void cpu_idle(void)
180{
181 local_fiq_enable();
182
183 /* endless idle loop with no priority at all */
184 while (1) {
Russell King9ccdac32009-06-22 22:34:55 +0100185 tick_nohz_stop_sched_tick(1);
186 leds_event(led_idle_start);
187 while (!need_resched()) {
Russell Kinga054a812005-11-02 22:24:33 +0000188#ifdef CONFIG_HOTPLUG_CPU
Russell King9ccdac32009-06-22 22:34:55 +0100189 if (cpu_is_offline(smp_processor_id()))
190 cpu_die();
Russell Kinga054a812005-11-02 22:24:33 +0000191#endif
192
Russell King9ccdac32009-06-22 22:34:55 +0100193 local_irq_disable();
194 if (hlt_counter) {
195 local_irq_enable();
196 cpu_relax();
197 } else {
198 stop_critical_timings();
David Browncbc158d2011-08-04 09:24:31 -0700199 if (cpuidle_idle_call())
Len Browna0bfa132011-04-01 19:34:59 -0400200 pm_idle();
Russell King9ccdac32009-06-22 22:34:55 +0100201 start_critical_timings();
202 /*
203 * This will eventually be removed - pm_idle
204 * functions should always return with IRQs
205 * enabled.
206 */
207 WARN_ON(irqs_disabled());
208 local_irq_enable();
209 }
210 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700211 leds_event(led_idle_end);
Kevin Hilman9e4559d2007-03-14 17:33:24 +0100212 tick_nohz_restart_sched_tick();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800213 preempt_enable_no_resched();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700214 schedule();
Nick Piggin5bfb5d62005-11-08 21:39:01 -0800215 preempt_disable();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700216 }
217}
218
219static char reboot_mode = 'h';
220
221int __init reboot_setup(char *str)
222{
223 reboot_mode = str[0];
224 return 1;
225}
226
227__setup("reboot=", reboot_setup);
228
Russell King3d3f78d2010-07-26 13:31:27 +0100229void machine_shutdown(void)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700230{
Russell King3d3f78d2010-07-26 13:31:27 +0100231#ifdef CONFIG_SMP
232 smp_send_stop();
233#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700234}
235
Russell King3d3f78d2010-07-26 13:31:27 +0100236void machine_halt(void)
237{
238 machine_shutdown();
239 while (1);
240}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700241
242void machine_power_off(void)
243{
Russell King3d3f78d2010-07-26 13:31:27 +0100244 machine_shutdown();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700245 if (pm_power_off)
246 pm_power_off();
247}
248
Russell Kingbe093be2009-03-19 16:20:24 +0000249void machine_restart(char *cmd)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250{
Russell King3d3f78d2010-07-26 13:31:27 +0100251 machine_shutdown();
Russell Kingac15e002011-10-31 09:22:22 +0000252
Russell Kingbe093be2009-03-19 16:20:24 +0000253 arm_pm_restart(reboot_mode, cmd);
Russell Kingac15e002011-10-31 09:22:22 +0000254
255 /* Give a grace period for failure to restart of 1s */
256 mdelay(1000);
257
258 /* Whoops - the platform was unable to reboot. Tell the user! */
259 printk("Reboot failed -- System halted\n");
260 while (1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261}
262
Russell King652a12e2005-04-17 15:50:36 +0100263void __show_regs(struct pt_regs *regs)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700264{
Russell King154c7722007-06-18 14:59:45 +0100265 unsigned long flags;
266 char buf[64];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700267
Russell King154c7722007-06-18 14:59:45 +0100268 printk("CPU: %d %s (%s %.*s)\n",
Rabin Vincent22325522010-01-08 16:59:34 +0100269 raw_smp_processor_id(), print_tainted(),
270 init_utsname()->release,
Russell King154c7722007-06-18 14:59:45 +0100271 (int)strcspn(init_utsname()->version, " "),
272 init_utsname()->version);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700273 print_symbol("PC is at %s\n", instruction_pointer(regs));
274 print_symbol("LR is at %s\n", regs->ARM_lr);
Russell King154c7722007-06-18 14:59:45 +0100275 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 "sp : %08lx ip : %08lx fp : %08lx\n",
Russell King154c7722007-06-18 14:59:45 +0100277 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
278 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700279 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
280 regs->ARM_r10, regs->ARM_r9,
281 regs->ARM_r8);
282 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
283 regs->ARM_r7, regs->ARM_r6,
284 regs->ARM_r5, regs->ARM_r4);
285 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
286 regs->ARM_r3, regs->ARM_r2,
287 regs->ARM_r1, regs->ARM_r0);
Russell King154c7722007-06-18 14:59:45 +0100288
289 flags = regs->ARM_cpsr;
290 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
291 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
292 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
293 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
294 buf[4] = '\0';
295
George G. Davis909d6c62007-06-26 01:38:27 +0100296 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
Russell King154c7722007-06-18 14:59:45 +0100297 buf, interrupts_enabled(regs) ? "n" : "ff",
Linus Torvalds1da177e2005-04-16 15:20:36 -0700298 fast_interrupts_enabled(regs) ? "n" : "ff",
299 processor_modes[processor_mode(regs)],
George G. Davis909d6c62007-06-26 01:38:27 +0100300 isa_modes[isa_mode(regs)],
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301 get_fs() == get_ds() ? "kernel" : "user");
Russell King154c7722007-06-18 14:59:45 +0100302#ifdef CONFIG_CPU_CP15
Linus Torvalds1da177e2005-04-16 15:20:36 -0700303 {
Hyok S. Choif12d0d72006-09-26 17:36:37 +0900304 unsigned int ctrl;
Russell King154c7722007-06-18 14:59:45 +0100305
306 buf[0] = '\0';
Hyok S. Choif12d0d72006-09-26 17:36:37 +0900307#ifdef CONFIG_CPU_CP15_MMU
Russell King154c7722007-06-18 14:59:45 +0100308 {
309 unsigned int transbase, dac;
310 asm("mrc p15, 0, %0, c2, c0\n\t"
311 "mrc p15, 0, %1, c3, c0\n"
312 : "=r" (transbase), "=r" (dac));
313 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
314 transbase, dac);
315 }
Hyok S. Choif12d0d72006-09-26 17:36:37 +0900316#endif
Russell King154c7722007-06-18 14:59:45 +0100317 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
318
319 printk("Control: %08x%s\n", ctrl, buf);
320 }
Hyok S. Choif12d0d72006-09-26 17:36:37 +0900321#endif
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322}
323
Russell King652a12e2005-04-17 15:50:36 +0100324void show_regs(struct pt_regs * regs)
325{
326 printk("\n");
Alexey Dobriyan19c58702007-10-18 23:40:41 -0700327 printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm);
Russell King652a12e2005-04-17 15:50:36 +0100328 __show_regs(regs);
Laura Abbottb380ab42011-08-31 02:04:06 +0100329 dump_stack();
Russell King652a12e2005-04-17 15:50:36 +0100330}
331
Russell King797245f2009-12-18 14:34:43 +0000332ATOMIC_NOTIFIER_HEAD(thread_notify_head);
333
334EXPORT_SYMBOL_GPL(thread_notify_head);
335
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700337 * Free current thread data structures etc..
338 */
339void exit_thread(void)
340{
Russell King797245f2009-12-18 14:34:43 +0000341 thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342}
343
Linus Torvalds1da177e2005-04-16 15:20:36 -0700344void flush_thread(void)
345{
346 struct thread_info *thread = current_thread_info();
347 struct task_struct *tsk = current;
348
Will Deacon864232f2010-09-03 10:42:55 +0100349 flush_ptrace_hw_breakpoint(tsk);
350
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351 memset(thread->used_cp, 0, sizeof(thread->used_cp));
352 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
Russell Kingd6551e82006-06-21 13:31:52 +0100353 memset(&thread->fpstate, 0, sizeof(union fp_state));
354
355 thread_notify(THREAD_NOTIFY_FLUSH, thread);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700356}
357
358void release_thread(struct task_struct *dead_task)
359{
Linus Torvalds1da177e2005-04-16 15:20:36 -0700360}
361
362asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
363
364int
Alexey Dobriyan6f2c55b2009-04-02 16:56:59 -0700365copy_thread(unsigned long clone_flags, unsigned long stack_start,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366 unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs)
367{
Al Viro815d5ec2006-01-12 01:05:57 -0800368 struct thread_info *thread = task_thread_info(p);
369 struct pt_regs *childregs = task_pt_regs(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700370
Linus Torvalds1da177e2005-04-16 15:20:36 -0700371 *childregs = *regs;
372 childregs->ARM_r0 = 0;
373 childregs->ARM_sp = stack_start;
374
375 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
376 thread->cpu_context.sp = (unsigned long)childregs;
377 thread->cpu_context.pc = (unsigned long)ret_from_fork;
378
Will Deacon864232f2010-09-03 10:42:55 +0100379 clear_ptrace_hw_breakpoint(p);
380
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 if (clone_flags & CLONE_SETTLS)
382 thread->tp_value = regs->ARM_r3;
383
Catalin Marinas2e826692011-04-06 16:16:29 +0100384 thread_notify(THREAD_NOTIFY_COPY, thread);
385
Linus Torvalds1da177e2005-04-16 15:20:36 -0700386 return 0;
387}
388
389/*
Artem Bityutskiycde3f862009-10-13 08:54:30 +0100390 * Fill in the task's elfregs structure for a core dump.
391 */
392int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
393{
394 elf_core_copy_regs(elfregs, task_pt_regs(t));
395 return 1;
396}
397
398/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700399 * fill in the fpe structure for a core dump...
400 */
401int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
402{
403 struct thread_info *thread = current_thread_info();
404 int used_math = thread->used_cp[1] | thread->used_cp[2];
405
406 if (used_math)
407 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
408
409 return used_math != 0;
410}
411EXPORT_SYMBOL(dump_fpu);
412
413/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700414 * Shuffle the argument into the correct register before calling the
Russell Kingac788842010-07-10 10:10:18 +0100415 * thread function. r4 is the thread argument, r5 is the pointer to
416 * the thread function, and r6 points to the exit function.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700417 */
418extern void kernel_thread_helper(void);
Russell King42604152010-04-19 10:15:03 +0100419asm( ".pushsection .text\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420" .align\n"
421" .type kernel_thread_helper, #function\n"
422"kernel_thread_helper:\n"
Russell Kingac788842010-07-10 10:10:18 +0100423#ifdef CONFIG_TRACE_IRQFLAGS
424" bl trace_hardirqs_on\n"
425#endif
426" msr cpsr_c, r7\n"
427" mov r0, r4\n"
428" mov lr, r6\n"
429" mov pc, r5\n"
Linus Torvalds1da177e2005-04-16 15:20:36 -0700430" .size kernel_thread_helper, . - kernel_thread_helper\n"
Russell King42604152010-04-19 10:15:03 +0100431" .popsection");
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432
Catalin Marinasfeb97c32009-06-19 16:43:08 +0100433#ifdef CONFIG_ARM_UNWIND
434extern void kernel_thread_exit(long code);
Russell King42604152010-04-19 10:15:03 +0100435asm( ".pushsection .text\n"
Catalin Marinasfeb97c32009-06-19 16:43:08 +0100436" .align\n"
437" .type kernel_thread_exit, #function\n"
438"kernel_thread_exit:\n"
439" .fnstart\n"
440" .cantunwind\n"
441" bl do_exit\n"
442" nop\n"
443" .fnend\n"
444" .size kernel_thread_exit, . - kernel_thread_exit\n"
Russell King42604152010-04-19 10:15:03 +0100445" .popsection");
Catalin Marinasfeb97c32009-06-19 16:43:08 +0100446#else
447#define kernel_thread_exit do_exit
448#endif
449
Linus Torvalds1da177e2005-04-16 15:20:36 -0700450/*
451 * Create a kernel thread.
452 */
453pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
454{
455 struct pt_regs regs;
456
457 memset(&regs, 0, sizeof(regs));
458
Russell Kingac788842010-07-10 10:10:18 +0100459 regs.ARM_r4 = (unsigned long)arg;
460 regs.ARM_r5 = (unsigned long)fn;
461 regs.ARM_r6 = (unsigned long)kernel_thread_exit;
462 regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700463 regs.ARM_pc = (unsigned long)kernel_thread_helper;
Russell Kingac788842010-07-10 10:10:18 +0100464 regs.ARM_cpsr = regs.ARM_r7 | PSR_I_BIT;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700465
466 return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, &regs, 0, NULL, NULL);
467}
468EXPORT_SYMBOL(kernel_thread);
469
470unsigned long get_wchan(struct task_struct *p)
471{
Catalin Marinas2d7c11b2009-02-11 13:07:53 +0100472 struct stackframe frame;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473 int count = 0;
474 if (!p || p == current || p->state == TASK_RUNNING)
475 return 0;
476
Catalin Marinas2d7c11b2009-02-11 13:07:53 +0100477 frame.fp = thread_saved_fp(p);
478 frame.sp = thread_saved_sp(p);
479 frame.lr = 0; /* recovered from the stack */
480 frame.pc = thread_saved_pc(p);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 do {
Catalin Marinas2d7c11b2009-02-11 13:07:53 +0100482 int ret = unwind_frame(&frame);
483 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700484 return 0;
Catalin Marinas2d7c11b2009-02-11 13:07:53 +0100485 if (!in_sched_functions(frame.pc))
486 return frame.pc;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700487 } while (count ++ < 16);
488 return 0;
489}
Nicolas Pitre990cb8a2010-06-14 16:27:19 -0400490
491unsigned long arch_randomize_brk(struct mm_struct *mm)
492{
493 unsigned long range_end = mm->brk + 0x02000000;
494 return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
495}
Nicolas Pitreec706da2010-08-26 23:10:50 -0400496
Will Deacon6cde6d42011-01-11 14:04:36 +0100497#ifdef CONFIG_MMU
Nicolas Pitreec706da2010-08-26 23:10:50 -0400498/*
499 * The vectors page is always readable from user space for the
500 * atomic helpers and the signal restart code. Let's declare a mapping
501 * for it so it is visible through ptrace and /proc/<pid>/mem.
502 */
503
504int vectors_user_mapping(void)
505{
506 struct mm_struct *mm = current->mm;
507 return install_special_mapping(mm, 0xffff0000, PAGE_SIZE,
508 VM_READ | VM_EXEC |
509 VM_MAYREAD | VM_MAYEXEC |
510 VM_ALWAYSDUMP | VM_RESERVED,
511 NULL);
512}
513
514const char *arch_vma_name(struct vm_area_struct *vma)
515{
516 return (vma->vm_start == 0xffff0000) ? "[vectors]" : NULL;
517}
Will Deacon6cde6d42011-01-11 14:04:36 +0100518#endif