Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris...
[linux/fpc-iii.git] / arch / arm / kernel / process.c
blob92f7b15dd22121d4aa674fd78cd95cac8924c07f
1 /*
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.
11 #include <stdarg.h>
13 #include <linux/export.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>
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>
27 #include <linux/pm.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>
34 #include <linux/leds.h>
35 #include <linux/reboot.h>
37 #include <asm/cacheflush.h>
38 #include <asm/idmap.h>
39 #include <asm/processor.h>
40 #include <asm/thread_notify.h>
41 #include <asm/stacktrace.h>
42 #include <asm/mach/time.h>
43 #include <asm/tls.h>
45 #ifdef CONFIG_CC_STACKPROTECTOR
46 #include <linux/stackprotector.h>
47 unsigned long __stack_chk_guard __read_mostly;
48 EXPORT_SYMBOL(__stack_chk_guard);
49 #endif
51 static const char *processor_modes[] = {
52 "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" ,
53 "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26",
54 "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" ,
55 "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32"
58 static const char *isa_modes[] = {
59 "ARM" , "Thumb" , "Jazelle", "ThumbEE"
62 extern void call_with_stack(void (*fn)(void *), void *arg, void *sp);
63 typedef void (*phys_reset_t)(unsigned long);
66 * A temporary stack to use for CPU reset. This is static so that we
67 * don't clobber it with the identity mapping. When running with this
68 * stack, any references to the current task *will not work* so you
69 * should really do as little as possible before jumping to your reset
70 * code.
72 static u64 soft_restart_stack[16];
74 static void __soft_restart(void *addr)
76 phys_reset_t phys_reset;
78 /* Take out a flat memory mapping. */
79 setup_mm_for_reboot();
81 /* Clean and invalidate caches */
82 flush_cache_all();
84 /* Turn off caching */
85 cpu_proc_fin();
87 /* Push out any further dirty data, and ensure cache is empty */
88 flush_cache_all();
90 /* Switch to the identity mapping. */
91 phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
92 phys_reset((unsigned long)addr);
94 /* Should never get here. */
95 BUG();
98 void soft_restart(unsigned long addr)
100 u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);
102 /* Disable interrupts first */
103 local_irq_disable();
104 local_fiq_disable();
106 /* Disable the L2 if we're the last man standing. */
107 if (num_online_cpus() == 1)
108 outer_disable();
110 /* Change to the new stack and continue with the reset. */
111 call_with_stack(__soft_restart, (void *)addr, (void *)stack);
113 /* Should never get here. */
114 BUG();
117 static void null_restart(enum reboot_mode reboot_mode, const char *cmd)
122 * Function pointers to optional machine specific functions
124 void (*pm_power_off)(void);
125 EXPORT_SYMBOL(pm_power_off);
127 void (*arm_pm_restart)(enum reboot_mode reboot_mode, const char *cmd) = null_restart;
128 EXPORT_SYMBOL_GPL(arm_pm_restart);
131 * This is our default idle handler.
134 void (*arm_pm_idle)(void);
136 static void default_idle(void)
138 if (arm_pm_idle)
139 arm_pm_idle();
140 else
141 cpu_do_idle();
142 local_irq_enable();
145 void arch_cpu_idle_prepare(void)
147 local_fiq_enable();
150 void arch_cpu_idle_enter(void)
152 ledtrig_cpu(CPU_LED_IDLE_START);
153 #ifdef CONFIG_PL310_ERRATA_769419
154 wmb();
155 #endif
158 void arch_cpu_idle_exit(void)
160 ledtrig_cpu(CPU_LED_IDLE_END);
163 #ifdef CONFIG_HOTPLUG_CPU
164 void arch_cpu_idle_dead(void)
166 cpu_die();
168 #endif
171 * Called from the core idle loop.
173 void arch_cpu_idle(void)
175 if (cpuidle_idle_call())
176 default_idle();
180 * Called by kexec, immediately prior to machine_kexec().
182 * This must completely disable all secondary CPUs; simply causing those CPUs
183 * to execute e.g. a RAM-based pin loop is not sufficient. This allows the
184 * kexec'd kernel to use any and all RAM as it sees fit, without having to
185 * avoid any code or data used by any SW CPU pin loop. The CPU hotplug
186 * functionality embodied in disable_nonboot_cpus() to achieve this.
188 void machine_shutdown(void)
190 disable_nonboot_cpus();
194 * Halting simply requires that the secondary CPUs stop performing any
195 * activity (executing tasks, handling interrupts). smp_send_stop()
196 * achieves this.
198 void machine_halt(void)
200 local_irq_disable();
201 smp_send_stop();
203 local_irq_disable();
204 while (1);
208 * Power-off simply requires that the secondary CPUs stop performing any
209 * activity (executing tasks, handling interrupts). smp_send_stop()
210 * achieves this. When the system power is turned off, it will take all CPUs
211 * with it.
213 void machine_power_off(void)
215 local_irq_disable();
216 smp_send_stop();
218 if (pm_power_off)
219 pm_power_off();
223 * Restart requires that the secondary CPUs stop performing any activity
224 * while the primary CPU resets the system. Systems with a single CPU can
225 * use soft_restart() as their machine descriptor's .restart hook, since that
226 * will cause the only available CPU to reset. Systems with multiple CPUs must
227 * provide a HW restart implementation, to ensure that all CPUs reset at once.
228 * This is required so that any code running after reset on the primary CPU
229 * doesn't have to co-ordinate with other CPUs to ensure they aren't still
230 * executing pre-reset code, and using RAM that the primary CPU's code wishes
231 * to use. Implementing such co-ordination would be essentially impossible.
233 void machine_restart(char *cmd)
235 local_irq_disable();
236 smp_send_stop();
238 arm_pm_restart(reboot_mode, cmd);
240 /* Give a grace period for failure to restart of 1s */
241 mdelay(1000);
243 /* Whoops - the platform was unable to reboot. Tell the user! */
244 printk("Reboot failed -- System halted\n");
245 local_irq_disable();
246 while (1);
249 void __show_regs(struct pt_regs *regs)
251 unsigned long flags;
252 char buf[64];
254 show_regs_print_info(KERN_DEFAULT);
256 print_symbol("PC is at %s\n", instruction_pointer(regs));
257 print_symbol("LR is at %s\n", regs->ARM_lr);
258 printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n"
259 "sp : %08lx ip : %08lx fp : %08lx\n",
260 regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr,
261 regs->ARM_sp, regs->ARM_ip, regs->ARM_fp);
262 printk("r10: %08lx r9 : %08lx r8 : %08lx\n",
263 regs->ARM_r10, regs->ARM_r9,
264 regs->ARM_r8);
265 printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n",
266 regs->ARM_r7, regs->ARM_r6,
267 regs->ARM_r5, regs->ARM_r4);
268 printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n",
269 regs->ARM_r3, regs->ARM_r2,
270 regs->ARM_r1, regs->ARM_r0);
272 flags = regs->ARM_cpsr;
273 buf[0] = flags & PSR_N_BIT ? 'N' : 'n';
274 buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z';
275 buf[2] = flags & PSR_C_BIT ? 'C' : 'c';
276 buf[3] = flags & PSR_V_BIT ? 'V' : 'v';
277 buf[4] = '\0';
279 printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n",
280 buf, interrupts_enabled(regs) ? "n" : "ff",
281 fast_interrupts_enabled(regs) ? "n" : "ff",
282 processor_modes[processor_mode(regs)],
283 isa_modes[isa_mode(regs)],
284 get_fs() == get_ds() ? "kernel" : "user");
285 #ifdef CONFIG_CPU_CP15
287 unsigned int ctrl;
289 buf[0] = '\0';
290 #ifdef CONFIG_CPU_CP15_MMU
292 unsigned int transbase, dac;
293 asm("mrc p15, 0, %0, c2, c0\n\t"
294 "mrc p15, 0, %1, c3, c0\n"
295 : "=r" (transbase), "=r" (dac));
296 snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x",
297 transbase, dac);
299 #endif
300 asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl));
302 printk("Control: %08x%s\n", ctrl, buf);
304 #endif
307 void show_regs(struct pt_regs * regs)
309 printk("\n");
310 __show_regs(regs);
311 dump_stack();
314 ATOMIC_NOTIFIER_HEAD(thread_notify_head);
316 EXPORT_SYMBOL_GPL(thread_notify_head);
319 * Free current thread data structures etc..
321 void exit_thread(void)
323 thread_notify(THREAD_NOTIFY_EXIT, current_thread_info());
326 void flush_thread(void)
328 struct thread_info *thread = current_thread_info();
329 struct task_struct *tsk = current;
331 flush_ptrace_hw_breakpoint(tsk);
333 memset(thread->used_cp, 0, sizeof(thread->used_cp));
334 memset(&tsk->thread.debug, 0, sizeof(struct debug_info));
335 memset(&thread->fpstate, 0, sizeof(union fp_state));
337 thread_notify(THREAD_NOTIFY_FLUSH, thread);
340 void release_thread(struct task_struct *dead_task)
344 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
347 copy_thread(unsigned long clone_flags, unsigned long stack_start,
348 unsigned long stk_sz, struct task_struct *p)
350 struct thread_info *thread = task_thread_info(p);
351 struct pt_regs *childregs = task_pt_regs(p);
353 memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
355 if (likely(!(p->flags & PF_KTHREAD))) {
356 *childregs = *current_pt_regs();
357 childregs->ARM_r0 = 0;
358 if (stack_start)
359 childregs->ARM_sp = stack_start;
360 } else {
361 memset(childregs, 0, sizeof(struct pt_regs));
362 thread->cpu_context.r4 = stk_sz;
363 thread->cpu_context.r5 = stack_start;
364 childregs->ARM_cpsr = SVC_MODE;
366 thread->cpu_context.pc = (unsigned long)ret_from_fork;
367 thread->cpu_context.sp = (unsigned long)childregs;
369 clear_ptrace_hw_breakpoint(p);
371 if (clone_flags & CLONE_SETTLS)
372 thread->tp_value[0] = childregs->ARM_r3;
373 thread->tp_value[1] = get_tpuser();
375 thread_notify(THREAD_NOTIFY_COPY, thread);
377 return 0;
381 * Fill in the task's elfregs structure for a core dump.
383 int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs)
385 elf_core_copy_regs(elfregs, task_pt_regs(t));
386 return 1;
390 * fill in the fpe structure for a core dump...
392 int dump_fpu (struct pt_regs *regs, struct user_fp *fp)
394 struct thread_info *thread = current_thread_info();
395 int used_math = thread->used_cp[1] | thread->used_cp[2];
397 if (used_math)
398 memcpy(fp, &thread->fpstate.soft, sizeof (*fp));
400 return used_math != 0;
402 EXPORT_SYMBOL(dump_fpu);
404 unsigned long get_wchan(struct task_struct *p)
406 struct stackframe frame;
407 unsigned long stack_page;
408 int count = 0;
409 if (!p || p == current || p->state == TASK_RUNNING)
410 return 0;
412 frame.fp = thread_saved_fp(p);
413 frame.sp = thread_saved_sp(p);
414 frame.lr = 0; /* recovered from the stack */
415 frame.pc = thread_saved_pc(p);
416 stack_page = (unsigned long)task_stack_page(p);
417 do {
418 if (frame.sp < stack_page ||
419 frame.sp >= stack_page + THREAD_SIZE ||
420 unwind_frame(&frame) < 0)
421 return 0;
422 if (!in_sched_functions(frame.pc))
423 return frame.pc;
424 } while (count ++ < 16);
425 return 0;
428 unsigned long arch_randomize_brk(struct mm_struct *mm)
430 unsigned long range_end = mm->brk + 0x02000000;
431 return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
434 #ifdef CONFIG_MMU
435 #ifdef CONFIG_KUSER_HELPERS
437 * The vectors page is always readable from user space for the
438 * atomic helpers. Insert it into the gate_vma so that it is visible
439 * through ptrace and /proc/<pid>/mem.
441 static struct vm_area_struct gate_vma = {
442 .vm_start = 0xffff0000,
443 .vm_end = 0xffff0000 + PAGE_SIZE,
444 .vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC,
447 static int __init gate_vma_init(void)
449 gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
450 return 0;
452 arch_initcall(gate_vma_init);
454 struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
456 return &gate_vma;
459 int in_gate_area(struct mm_struct *mm, unsigned long addr)
461 return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
464 int in_gate_area_no_mm(unsigned long addr)
466 return in_gate_area(NULL, addr);
468 #define is_gate_vma(vma) ((vma) == &gate_vma)
469 #else
470 #define is_gate_vma(vma) 0
471 #endif
473 const char *arch_vma_name(struct vm_area_struct *vma)
475 return is_gate_vma(vma) ? "[vectors]" :
476 (vma->vm_mm && vma->vm_start == vma->vm_mm->context.sigpage) ?
477 "[sigpage]" : NULL;
480 static struct page *signal_page;
481 extern struct page *get_signal_page(void);
483 int arch_setup_additional_pages(struct linux_binprm *bprm, int uses_interp)
485 struct mm_struct *mm = current->mm;
486 unsigned long addr;
487 int ret;
489 if (!signal_page)
490 signal_page = get_signal_page();
491 if (!signal_page)
492 return -ENOMEM;
494 down_write(&mm->mmap_sem);
495 addr = get_unmapped_area(NULL, 0, PAGE_SIZE, 0, 0);
496 if (IS_ERR_VALUE(addr)) {
497 ret = addr;
498 goto up_fail;
501 ret = install_special_mapping(mm, addr, PAGE_SIZE,
502 VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYWRITE | VM_MAYEXEC,
503 &signal_page);
505 if (ret == 0)
506 mm->context.sigpage = addr;
508 up_fail:
509 up_write(&mm->mmap_sem);
510 return ret;
512 #endif