2 * linux/arch/arm/kernel/process.c
4 * Copyright (C) 1996-2000 Russell King - Converted to ARM.
5 * Original Copyright (C) 1995 Linus Torvalds
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.
13 #include <linux/export.h>
14 #include <linux/sched.h>
15 #include <linux/kernel.h>
17 #include <linux/stddef.h>
18 #include <linux/unistd.h>
19 #include <linux/user.h>
20 #include <linux/delay.h>
21 #include <linux/reboot.h>
22 #include <linux/interrupt.h>
23 #include <linux/kallsyms.h>
24 #include <linux/init.h>
25 #include <linux/cpu.h>
26 #include <linux/elfcore.h>
28 #include <linux/tick.h>
29 #include <linux/utsname.h>
30 #include <linux/uaccess.h>
31 #include <linux/random.h>
32 #include <linux/hw_breakpoint.h>
33 #include <linux/cpuidle.h>
35 #include <asm/cacheflush.h>
37 #include <asm/processor.h>
38 #include <asm/system.h>
39 #include <asm/thread_notify.h>
40 #include <asm/stacktrace.h>
41 #include <asm/mach/time.h>
43 #ifdef CONFIG_CC_STACKPROTECTOR
44 #include <linux/stackprotector.h>
45 unsigned long __stack_chk_guard __read_mostly
;
46 EXPORT_SYMBOL(__stack_chk_guard
);
49 static 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"
56 static const char *isa_modes
[] = {
57 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
60 extern void setup_mm_for_reboot(char mode
);
62 static volatile int hlt_counter
;
64 #include <mach/system.h>
66 void disable_hlt(void)
71 EXPORT_SYMBOL(disable_hlt
);
78 EXPORT_SYMBOL(enable_hlt
);
80 static int __init
nohlt_setup(char *__unused
)
86 static int __init
hlt_setup(char *__unused
)
92 __setup("nohlt", nohlt_setup
);
93 __setup("hlt", hlt_setup
);
95 void arm_machine_restart(char mode
, const char *cmd
)
97 /* Disable interrupts first */
102 * Tell the mm system that we are going to reboot -
103 * we may need it to insert some 1:1 mappings so that
106 setup_mm_for_reboot(mode
);
108 /* Clean and invalidate caches */
111 /* Turn off caching */
114 /* Push out any further dirty data, and ensure cache is empty */
118 * Now call the architecture specific reboot code.
120 arch_reset(mode
, cmd
);
123 * Whoops - the architecture was unable to reboot.
127 printk("Reboot failed -- System halted\n");
132 * Function pointers to optional machine specific functions
134 void (*pm_power_off
)(void);
135 EXPORT_SYMBOL(pm_power_off
);
137 void (*arm_pm_restart
)(char str
, const char *cmd
) = arm_machine_restart
;
138 EXPORT_SYMBOL_GPL(arm_pm_restart
);
140 static void do_nothing(void *unused
)
145 * cpu_idle_wait - Used to ensure that all the CPUs discard old value of
146 * pm_idle and update to new pm_idle value. Required while changing pm_idle
147 * handler on SMP systems.
149 * Caller must have changed pm_idle to the new value before the call. Old
150 * pm_idle value will not be used by any CPU after the return of this function.
152 void cpu_idle_wait(void)
155 /* kick all the CPUs so that they exit out of pm_idle */
156 smp_call_function(do_nothing
, NULL
, 1);
158 EXPORT_SYMBOL_GPL(cpu_idle_wait
);
161 * This is our default idle handler. We need to disable
162 * interrupts here to ensure we don't miss a wakeup call.
164 static void default_idle(void)
171 void (*pm_idle
)(void) = default_idle
;
172 EXPORT_SYMBOL(pm_idle
);
175 * The idle thread, has rather strange semantics for calling pm_idle,
176 * but this is what x86 does and we need to do the same, so that
177 * things like cpuidle get called in the same way. The only difference
178 * is that we always respect 'hlt_counter' to prevent low power idle.
184 /* endless idle loop with no priority at all */
186 tick_nohz_stop_sched_tick(1);
187 leds_event(led_idle_start
);
188 while (!need_resched()) {
189 #ifdef CONFIG_HOTPLUG_CPU
190 if (cpu_is_offline(smp_processor_id()))
195 #ifdef CONFIG_PL310_ERRATA_769419
202 stop_critical_timings();
203 if (cpuidle_idle_call())
205 start_critical_timings();
207 * This will eventually be removed - pm_idle
208 * functions should always return with IRQs
211 WARN_ON(irqs_disabled());
215 leds_event(led_idle_end
);
216 tick_nohz_restart_sched_tick();
217 preempt_enable_no_resched();
223 static char reboot_mode
= 'h';
225 int __init
reboot_setup(char *str
)
227 reboot_mode
= str
[0];
231 __setup("reboot=", reboot_setup
);
233 void machine_shutdown(void)
240 void machine_halt(void)
246 void machine_power_off(void)
253 void machine_restart(char *cmd
)
256 arm_pm_restart(reboot_mode
, cmd
);
259 void __show_regs(struct pt_regs
*regs
)
264 printk("CPU: %d %s (%s %.*s)\n",
265 raw_smp_processor_id(), print_tainted(),
266 init_utsname()->release
,
267 (int)strcspn(init_utsname()->version
, " "),
268 init_utsname()->version
);
269 print_symbol("PC is at %s\n", instruction_pointer(regs
));
270 print_symbol("LR is at %s\n", regs
->ARM_lr
);
271 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
272 "sp : %08lx ip : %08lx fp : %08lx\n",
273 regs
->ARM_pc
, regs
->ARM_lr
, regs
->ARM_cpsr
,
274 regs
->ARM_sp
, regs
->ARM_ip
, regs
->ARM_fp
);
275 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
276 regs
->ARM_r10
, regs
->ARM_r9
,
278 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
279 regs
->ARM_r7
, regs
->ARM_r6
,
280 regs
->ARM_r5
, regs
->ARM_r4
);
281 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
282 regs
->ARM_r3
, regs
->ARM_r2
,
283 regs
->ARM_r1
, regs
->ARM_r0
);
285 flags
= regs
->ARM_cpsr
;
286 buf
[0] = flags
& PSR_N_BIT
? 'N' : 'n';
287 buf
[1] = flags
& PSR_Z_BIT
? 'Z' : 'z';
288 buf
[2] = flags
& PSR_C_BIT
? 'C' : 'c';
289 buf
[3] = flags
& PSR_V_BIT
? 'V' : 'v';
292 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
293 buf
, interrupts_enabled(regs
) ? "n" : "ff",
294 fast_interrupts_enabled(regs
) ? "n" : "ff",
295 processor_modes
[processor_mode(regs
)],
296 isa_modes
[isa_mode(regs
)],
297 get_fs() == get_ds() ? "kernel" : "user");
298 #ifdef CONFIG_CPU_CP15
303 #ifdef CONFIG_CPU_CP15_MMU
305 unsigned int transbase
, dac
;
306 asm("mrc p15, 0, %0, c2, c0\n\t"
307 "mrc p15, 0, %1, c3, c0\n"
308 : "=r" (transbase
), "=r" (dac
));
309 snprintf(buf
, sizeof(buf
), " Table: %08x DAC: %08x",
313 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl
));
315 printk("Control: %08x%s\n", ctrl
, buf
);
320 void show_regs(struct pt_regs
* regs
)
323 printk("Pid: %d, comm: %20s\n", task_pid_nr(current
), current
->comm
);
328 ATOMIC_NOTIFIER_HEAD(thread_notify_head
);
330 EXPORT_SYMBOL_GPL(thread_notify_head
);
333 * Free current thread data structures etc..
335 void exit_thread(void)
337 thread_notify(THREAD_NOTIFY_EXIT
, current_thread_info());
340 void flush_thread(void)
342 struct thread_info
*thread
= current_thread_info();
343 struct task_struct
*tsk
= current
;
345 flush_ptrace_hw_breakpoint(tsk
);
347 memset(thread
->used_cp
, 0, sizeof(thread
->used_cp
));
348 memset(&tsk
->thread
.debug
, 0, sizeof(struct debug_info
));
349 memset(&thread
->fpstate
, 0, sizeof(union fp_state
));
351 thread_notify(THREAD_NOTIFY_FLUSH
, thread
);
354 void release_thread(struct task_struct
*dead_task
)
358 asmlinkage
void ret_from_fork(void) __asm__("ret_from_fork");
361 copy_thread(unsigned long clone_flags
, unsigned long stack_start
,
362 unsigned long stk_sz
, struct task_struct
*p
, struct pt_regs
*regs
)
364 struct thread_info
*thread
= task_thread_info(p
);
365 struct pt_regs
*childregs
= task_pt_regs(p
);
368 childregs
->ARM_r0
= 0;
369 childregs
->ARM_sp
= stack_start
;
371 memset(&thread
->cpu_context
, 0, sizeof(struct cpu_context_save
));
372 thread
->cpu_context
.sp
= (unsigned long)childregs
;
373 thread
->cpu_context
.pc
= (unsigned long)ret_from_fork
;
375 clear_ptrace_hw_breakpoint(p
);
377 if (clone_flags
& CLONE_SETTLS
)
378 thread
->tp_value
= regs
->ARM_r3
;
380 thread_notify(THREAD_NOTIFY_COPY
, thread
);
386 * Fill in the task's elfregs structure for a core dump.
388 int dump_task_regs(struct task_struct
*t
, elf_gregset_t
*elfregs
)
390 elf_core_copy_regs(elfregs
, task_pt_regs(t
));
395 * fill in the fpe structure for a core dump...
397 int dump_fpu (struct pt_regs
*regs
, struct user_fp
*fp
)
399 struct thread_info
*thread
= current_thread_info();
400 int used_math
= thread
->used_cp
[1] | thread
->used_cp
[2];
403 memcpy(fp
, &thread
->fpstate
.soft
, sizeof (*fp
));
405 return used_math
!= 0;
407 EXPORT_SYMBOL(dump_fpu
);
410 * Shuffle the argument into the correct register before calling the
411 * thread function. r4 is the thread argument, r5 is the pointer to
412 * the thread function, and r6 points to the exit function.
414 extern void kernel_thread_helper(void);
415 asm( ".pushsection .text\n"
417 " .type kernel_thread_helper, #function\n"
418 "kernel_thread_helper:\n"
419 #ifdef CONFIG_TRACE_IRQFLAGS
420 " bl trace_hardirqs_on\n"
426 " .size kernel_thread_helper, . - kernel_thread_helper\n"
429 #ifdef CONFIG_ARM_UNWIND
430 extern void kernel_thread_exit(long code
);
431 asm( ".pushsection .text\n"
433 " .type kernel_thread_exit, #function\n"
434 "kernel_thread_exit:\n"
440 " .size kernel_thread_exit, . - kernel_thread_exit\n"
443 #define kernel_thread_exit do_exit
447 * Create a kernel thread.
449 pid_t
kernel_thread(int (*fn
)(void *), void *arg
, unsigned long flags
)
453 memset(®s
, 0, sizeof(regs
));
455 regs
.ARM_r4
= (unsigned long)arg
;
456 regs
.ARM_r5
= (unsigned long)fn
;
457 regs
.ARM_r6
= (unsigned long)kernel_thread_exit
;
458 regs
.ARM_r7
= SVC_MODE
| PSR_ENDSTATE
| PSR_ISETSTATE
;
459 regs
.ARM_pc
= (unsigned long)kernel_thread_helper
;
460 regs
.ARM_cpsr
= regs
.ARM_r7
| PSR_I_BIT
;
462 return do_fork(flags
|CLONE_VM
|CLONE_UNTRACED
, 0, ®s
, 0, NULL
, NULL
);
464 EXPORT_SYMBOL(kernel_thread
);
466 unsigned long get_wchan(struct task_struct
*p
)
468 struct stackframe frame
;
470 if (!p
|| p
== current
|| p
->state
== TASK_RUNNING
)
473 frame
.fp
= thread_saved_fp(p
);
474 frame
.sp
= thread_saved_sp(p
);
475 frame
.lr
= 0; /* recovered from the stack */
476 frame
.pc
= thread_saved_pc(p
);
478 int ret
= unwind_frame(&frame
);
481 if (!in_sched_functions(frame
.pc
))
483 } while (count
++ < 16);
487 unsigned long arch_randomize_brk(struct mm_struct
*mm
)
489 unsigned long range_end
= mm
->brk
+ 0x02000000;
490 return randomize_range(mm
->brk
, range_end
, 0) ? : mm
->brk
;
495 * The vectors page is always readable from user space for the
496 * atomic helpers and the signal restart code. Let's declare a mapping
497 * for it so it is visible through ptrace and /proc/<pid>/mem.
500 int vectors_user_mapping(void)
502 struct mm_struct
*mm
= current
->mm
;
503 return install_special_mapping(mm
, 0xffff0000, PAGE_SIZE
,
505 VM_MAYREAD
| VM_MAYEXEC
|
506 VM_ALWAYSDUMP
| VM_RESERVED
,
510 const char *arch_vma_name(struct vm_area_struct
*vma
)
512 return (vma
->vm_start
== 0xffff0000) ? "[vectors]" : NULL
;