/* * linux/arch/arm/kernel/process.c * * Copyright (C) 1996-2000 Russell King - Converted to ARM. * Original Copyright (C) 1995 Linus Torvalds * * This program is free software; you can redistribute it and/or modify * it under the terms of the GNU General Public License version 2 as * published by the Free Software Foundation. */ #include <stdarg.h> #include <linux/module.h> #include <linux/sched.h> #include <linux/kernel.h> #include <linux/mm.h> #include <linux/stddef.h> #include <linux/unistd.h> #include <linux/user.h> #include <linux/delay.h> #include <linux/reboot.h> #include <linux/interrupt.h> #include <linux/kallsyms.h> #include <linux/init.h> #include <linux/cpu.h> #include <linux/elfcore.h> #include <linux/pm.h> #include <linux/tick.h> #include <linux/utsname.h> #include <linux/uaccess.h> #include <asm/leds.h> #include <asm/processor.h> #include <asm/system.h> #include <asm/thread_notify.h> #include <asm/stacktrace.h> #include <asm/mach/time.h> static const char *processor_modes[] = { "USER_26", "FIQ_26" , "IRQ_26" , "SVC_26" , "UK4_26" , "UK5_26" , "UK6_26" , "UK7_26" , "UK8_26" , "UK9_26" , "UK10_26", "UK11_26", "UK12_26", "UK13_26", "UK14_26", "UK15_26", "USER_32", "FIQ_32" , "IRQ_32" , "SVC_32" , "UK4_32" , "UK5_32" , "UK6_32" , "ABT_32" , "UK8_32" , "UK9_32" , "UK10_32", "UND_32" , "UK12_32", "UK13_32", "UK14_32", "SYS_32" }; static const char *isa_modes[] = { "ARM" , "Thumb" , "Jazelle", "ThumbEE" }; extern void setup_mm_for_reboot(char mode); static volatile int hlt_counter; #include <mach/system.h> void disable_hlt(void) { hlt_counter++; } EXPORT_SYMBOL(disable_hlt); void enable_hlt(void) { hlt_counter--; } EXPORT_SYMBOL(enable_hlt); static int __init nohlt_setup(char *__unused) { hlt_counter = 1; return 1; } static int __init hlt_setup(char *__unused) { hlt_counter = 0; return 1; } __setup("nohlt", nohlt_setup); __setup("hlt", hlt_setup); void arm_machine_restart(char mode, const char *cmd) { /* * Clean and disable cache, and turn off interrupts */ cpu_proc_fin(); /* * Tell the mm system that we are going to reboot - * we may need it to insert some 1:1 mappings so that * soft boot works. */ setup_mm_for_reboot(mode); /* * Now call the architecture specific reboot code. */ arch_reset(mode, cmd); /* * Whoops - the architecture was unable to reboot. * Tell the user! */ mdelay(1000); printk("Reboot failed -- System halted\n"); while (1); } /* * Function pointers to optional machine specific functions */ void (*pm_power_off)(void); EXPORT_SYMBOL(pm_power_off); void (*arm_pm_restart)(char str, const char *cmd) = arm_machine_restart; EXPORT_SYMBOL_GPL(arm_pm_restart); /* * This is our default idle handler. We need to disable * interrupts here to ensure we don't miss a wakeup call. */ static void default_idle(void) { if (!need_resched()) arch_idle(); local_irq_enable(); } void (*pm_idle)(void) = default_idle; EXPORT_SYMBOL(pm_idle); /* * The idle thread, has rather strange semantics for calling pm_idle, * but this is what x86 does and we need to do the same, so that * things like cpuidle get called in the same way. The only difference * is that we always respect 'hlt_counter' to prevent low power idle. */ void cpu_idle(void) { local_fiq_enable(); /* endless idle loop with no priority at all */ while (1) { tick_nohz_stop_sched_tick(1); leds_event(led_idle_start); while (!need_resched()) { #ifdef CONFIG_HOTPLUG_CPU if (cpu_is_offline(smp_processor_id())) cpu_die(); #endif local_irq_disable(); if (hlt_counter) { local_irq_enable(); cpu_relax(); } else { stop_critical_timings(); pm_idle(); start_critical_timings(); /* * This will eventually be removed - pm_idle * functions should always return with IRQs * enabled. */ WARN_ON(irqs_disabled()); local_irq_enable(); } } leds_event(led_idle_end); tick_nohz_restart_sched_tick(); preempt_enable_no_resched(); schedule(); preempt_disable(); } } static char reboot_mode = 'h'; int __init reboot_setup(char *str) { reboot_mode = str[0]; return 1; } __setup("reboot=", reboot_setup); void machine_halt(void) { } void machine_power_off(void) { if (pm_power_off) pm_power_off(); } void machine_restart(char *cmd) { arm_pm_restart(reboot_mode, cmd); } void __show_regs(struct pt_regs *regs) { unsigned long flags; char buf[64]; printk("CPU: %d %s (%s %.*s)\n", raw_smp_processor_id(), print_tainted(), init_utsname()->release, (int)strcspn(init_utsname()->version, " "), init_utsname()->version); print_symbol("PC is at %s\n", instruction_pointer(regs)); print_symbol("LR is at %s\n", regs->ARM_lr); printk("pc : [<%08lx>] lr : [<%08lx>] psr: %08lx\n" "sp : %08lx ip : %08lx fp : %08lx\n", regs->ARM_pc, regs->ARM_lr, regs->ARM_cpsr, regs->ARM_sp, regs->ARM_ip, regs->ARM_fp); printk("r10: %08lx r9 : %08lx r8 : %08lx\n", regs->ARM_r10, regs->ARM_r9, regs->ARM_r8); printk("r7 : %08lx r6 : %08lx r5 : %08lx r4 : %08lx\n", regs->ARM_r7, regs->ARM_r6, regs->ARM_r5, regs->ARM_r4); printk("r3 : %08lx r2 : %08lx r1 : %08lx r0 : %08lx\n", regs->ARM_r3, regs->ARM_r2, regs->ARM_r1, regs->ARM_r0); flags = regs->ARM_cpsr; buf[0] = flags & PSR_N_BIT ? 'N' : 'n'; buf[1] = flags & PSR_Z_BIT ? 'Z' : 'z'; buf[2] = flags & PSR_C_BIT ? 'C' : 'c'; buf[3] = flags & PSR_V_BIT ? 'V' : 'v'; buf[4] = '\0'; printk("Flags: %s IRQs o%s FIQs o%s Mode %s ISA %s Segment %s\n", buf, interrupts_enabled(regs) ? "n" : "ff", fast_interrupts_enabled(regs) ? "n" : "ff", processor_modes[processor_mode(regs)], isa_modes[isa_mode(regs)], get_fs() == get_ds() ? "kernel" : "user"); #ifdef CONFIG_CPU_CP15 { unsigned int ctrl; buf[0] = '\0'; #ifdef CONFIG_CPU_CP15_MMU { unsigned int transbase, dac; asm("mrc p15, 0, %0, c2, c0\n\t" "mrc p15, 0, %1, c3, c0\n" : "=r" (transbase), "=r" (dac)); snprintf(buf, sizeof(buf), " Table: %08x DAC: %08x", transbase, dac); } #endif asm("mrc p15, 0, %0, c1, c0\n" : "=r" (ctrl)); printk("Control: %08x%s\n", ctrl, buf); } #endif } void show_regs(struct pt_regs * regs) { printk("\n"); printk("Pid: %d, comm: %20s\n", task_pid_nr(current), current->comm); __show_regs(regs); __backtrace(); } ATOMIC_NOTIFIER_HEAD(thread_notify_head); EXPORT_SYMBOL_GPL(thread_notify_head); /* * Free current thread data structures etc.. */ void exit_thread(void) { thread_notify(THREAD_NOTIFY_EXIT, current_thread_info()); } void flush_thread(void) { struct thread_info *thread = current_thread_info(); struct task_struct *tsk = current; memset(thread->used_cp, 0, sizeof(thread->used_cp)); memset(&tsk->thread.debug, 0, sizeof(struct debug_info)); memset(&thread->fpstate, 0, sizeof(union fp_state)); thread_notify(THREAD_NOTIFY_FLUSH, thread); } void release_thread(struct task_struct *dead_task) { } asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); int copy_thread(unsigned long clone_flags, unsigned long stack_start, unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) { struct thread_info *thread = task_thread_info(p); struct pt_regs *childregs = task_pt_regs(p); *childregs = *regs; childregs->ARM_r0 = 0; childregs->ARM_sp = stack_start; memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save)); thread->cpu_context.sp = (unsigned long)childregs; thread->cpu_context.pc = (unsigned long)ret_from_fork; if (clone_flags & CLONE_SETTLS) thread->tp_value = regs->ARM_r3; return 0; } /* * Fill in the task's elfregs structure for a core dump. */ int dump_task_regs(struct task_struct *t, elf_gregset_t *elfregs) { elf_core_copy_regs(elfregs, task_pt_regs(t)); return 1; } /* * fill in the fpe structure for a core dump... */ int dump_fpu (struct pt_regs *regs, struct user_fp *fp) { struct thread_info *thread = current_thread_info(); int used_math = thread->used_cp[1] | thread->used_cp[2]; if (used_math) memcpy(fp, &thread->fpstate.soft, sizeof (*fp)); return used_math != 0; } EXPORT_SYMBOL(dump_fpu); /* * Shuffle the argument into the correct register before calling the * thread function. r4 is the thread argument, r5 is the pointer to * the thread function, and r6 points to the exit function. */ extern void kernel_thread_helper(void); asm( ".pushsection .text\n" " .align\n" " .type kernel_thread_helper, #function\n" "kernel_thread_helper:\n" #ifdef CONFIG_TRACE_IRQFLAGS " bl trace_hardirqs_on\n" #endif " msr cpsr_c, r7\n" " mov r0, r4\n" " mov lr, r6\n" " mov pc, r5\n" " .size kernel_thread_helper, . - kernel_thread_helper\n" " .popsection"); #ifdef CONFIG_ARM_UNWIND extern void kernel_thread_exit(long code); asm( ".pushsection .text\n" " .align\n" " .type kernel_thread_exit, #function\n" "kernel_thread_exit:\n" " .fnstart\n" " .cantunwind\n" " bl do_exit\n" " nop\n" " .fnend\n" " .size kernel_thread_exit, . - kernel_thread_exit\n" " .popsection"); #else #define kernel_thread_exit do_exit #endif /* * Create a kernel thread. */ pid_t kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) { struct pt_regs regs; memset(®s, 0, sizeof(regs)); regs.ARM_r4 = (unsigned long)arg; regs.ARM_r5 = (unsigned long)fn; regs.ARM_r6 = (unsigned long)kernel_thread_exit; regs.ARM_r7 = SVC_MODE | PSR_ENDSTATE | PSR_ISETSTATE; regs.ARM_pc = (unsigned long)kernel_thread_helper; regs.ARM_cpsr = regs.ARM_r7 | PSR_I_BIT; return do_fork(flags|CLONE_VM|CLONE_UNTRACED, 0, ®s, 0, NULL, NULL); } EXPORT_SYMBOL(kernel_thread); unsigned long get_wchan(struct task_struct *p) { struct stackframe frame; int count = 0; if (!p || p == current || p->state == TASK_RUNNING) return 0; frame.fp = thread_saved_fp(p); frame.sp = thread_saved_sp(p); frame.lr = 0; /* recovered from the stack */ frame.pc = thread_saved_pc(p); do { int ret = unwind_frame(&frame); if (ret < 0) return 0; if (!in_sched_functions(frame.pc)) return frame.pc; } while (count ++ < 16); return 0; }