/* * 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/config.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/ptrace.h> #include <linux/slab.h> #include <linux/user.h> #include <linux/a.out.h> #include <linux/delay.h> #include <linux/reboot.h> #include <linux/interrupt.h> #include <linux/kallsyms.h> #include <linux/init.h> #include <asm/system.h> #include <asm/io.h> #include <asm/leds.h> #include <asm/processor.h> #include <asm/uaccess.h> #include <asm/mach/time.h> extern const char *processor_modes[]; extern void setup_mm_for_reboot(char mode); static volatile int hlt_counter; #include <asm/arch/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); /* * The following aren't currently used. */ void (*pm_idle)(void); EXPORT_SYMBOL(pm_idle); void (*pm_power_off)(void); EXPORT_SYMBOL(pm_power_off); /* * This is our default idle handler. We need to disable * interrupts here to ensure we don't miss a wakeup call. */ void default_idle(void) { local_irq_disable(); if (!need_resched() && !hlt_counter) { timer_dyn_reprogram(); arch_idle(); } local_irq_enable(); } /* * The idle thread. We try to conserve power, while trying to keep * overall latency low. The architecture specific idle is passed * a value to indicate the level of "idleness" of the system. */ void cpu_idle(void) { local_fiq_enable(); /* endless idle loop with no priority at all */ while (1) { void (*idle)(void) = pm_idle; if (!idle) idle = default_idle; preempt_disable(); leds_event(led_idle_start); while (!need_resched()) idle(); leds_event(led_idle_end); preempt_enable(); schedule(); } } 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 * __unused) { /* * 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(reboot_mode); /* * Now call the architecture specific reboot code. */ arch_reset(reboot_mode); /* * Whoops - the architecture was unable to reboot. * Tell the user! */ mdelay(1000); printk("Reboot failed -- System halted\n"); while (1); } void __show_regs(struct pt_regs *regs) { unsigned long flags = condition_codes(regs); printk("CPU: %d\n", smp_processor_id()); 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>] %s\n" "sp : %08lx ip : %08lx fp : %08lx\n", instruction_pointer(regs), regs->ARM_lr, print_tainted(), 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); printk("Flags: %c%c%c%c", flags & PSR_N_BIT ? 'N' : 'n', flags & PSR_Z_BIT ? 'Z' : 'z', flags & PSR_C_BIT ? 'C' : 'c', flags & PSR_V_BIT ? 'V' : 'v'); printk(" IRQs o%s FIQs o%s Mode %s%s Segment %s\n", interrupts_enabled(regs) ? "n" : "ff", fast_interrupts_enabled(regs) ? "n" : "ff", processor_modes[processor_mode(regs)], thumb_mode(regs) ? " (T)" : "", get_fs() == get_ds() ? "kernel" : "user"); { unsigned int ctrl, transbase, dac; __asm__ ( " mrc p15, 0, %0, c1, c0\n" " mrc p15, 0, %1, c2, c0\n" " mrc p15, 0, %2, c3, c0\n" : "=r" (ctrl), "=r" (transbase), "=r" (dac)); printk("Control: %04X Table: %08X DAC: %08X\n", ctrl, transbase, dac); } } void show_regs(struct pt_regs * regs) { printk("\n"); printk("Pid: %d, comm: %20s\n", current->pid, current->comm); __show_regs(regs); __backtrace(); } void show_fpregs(struct user_fp *regs) { int i; for (i = 0; i < 8; i++) { unsigned long *p; char type; p = (unsigned long *)(regs->fpregs + i); switch (regs->ftype[i]) { case 1: type = 'f'; break; case 2: type = 'd'; break; case 3: type = 'e'; break; default: type = '?'; break; } if (regs->init_flag) type = '?'; printk(" f%d(%c): %08lx %08lx %08lx%c", i, type, p[0], p[1], p[2], i & 1 ? '\n' : ' '); } printk("FPSR: %08lx FPCR: %08lx\n", (unsigned long)regs->fpsr, (unsigned long)regs->fpcr); } /* * Task structure and kernel stack allocation. */ static unsigned long *thread_info_head; static unsigned int nr_thread_info; #define EXTRA_TASK_STRUCT 4 struct thread_info *alloc_thread_info(struct task_struct *task) { struct thread_info *thread = NULL; if (EXTRA_TASK_STRUCT) { unsigned long *p = thread_info_head; if (p) { thread_info_head = (unsigned long *)p[0]; nr_thread_info -= 1; } thread = (struct thread_info *)p; } if (!thread) thread = (struct thread_info *) __get_free_pages(GFP_KERNEL, THREAD_SIZE_ORDER); #ifdef CONFIG_DEBUG_STACK_USAGE /* * The stack must be cleared if you want SYSRQ-T to * give sensible stack usage information */ if (thread) memzero(thread, THREAD_SIZE); #endif return thread; } void free_thread_info(struct thread_info *thread) { if (EXTRA_TASK_STRUCT && nr_thread_info < EXTRA_TASK_STRUCT) { unsigned long *p = (unsigned long *)thread; p[0] = (unsigned long)thread_info_head; thread_info_head = p; nr_thread_info += 1; } else free_pages((unsigned long)thread, THREAD_SIZE_ORDER); } /* * Free current thread data structures etc.. */ void exit_thread(void) { } static void default_fp_init(union fp_state *fp) { memset(fp, 0, sizeof(union fp_state)); } void (*fp_init)(union fp_state *) = default_fp_init; EXPORT_SYMBOL(fp_init); 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)); #if defined(CONFIG_IWMMXT) iwmmxt_task_release(thread); #endif fp_init(&thread->fpstate); #if defined(CONFIG_VFP) vfp_flush_thread(&thread->vfpstate); #endif } void release_thread(struct task_struct *dead_task) { #if defined(CONFIG_VFP) vfp_release_thread(&dead_task->thread_info->vfpstate); #endif #if defined(CONFIG_IWMMXT) iwmmxt_task_release(dead_task->thread_info); #endif } asmlinkage void ret_from_fork(void) __asm__("ret_from_fork"); int copy_thread(int nr, unsigned long clone_flags, unsigned long stack_start, unsigned long stk_sz, struct task_struct *p, struct pt_regs *regs) { struct thread_info *thread = p->thread_info; struct pt_regs *childregs; childregs = ((struct pt_regs *)((unsigned long)thread + THREAD_START_SP)) - 1; *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 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); /* * fill in the user structure for a core dump.. */ void dump_thread(struct pt_regs * regs, struct user * dump) { struct task_struct *tsk = current; dump->magic = CMAGIC; dump->start_code = tsk->mm->start_code; dump->start_stack = regs->ARM_sp & ~(PAGE_SIZE - 1); dump->u_tsize = (tsk->mm->end_code - tsk->mm->start_code) >> PAGE_SHIFT; dump->u_dsize = (tsk->mm->brk - tsk->mm->start_data + PAGE_SIZE - 1) >> PAGE_SHIFT; dump->u_ssize = 0; dump->u_debugreg[0] = tsk->thread.debug.bp[0].address; dump->u_debugreg[1] = tsk->thread.debug.bp[1].address; dump->u_debugreg[2] = tsk->thread.debug.bp[0].insn.arm; dump->u_debugreg[3] = tsk->thread.debug.bp[1].insn.arm; dump->u_debugreg[4] = tsk->thread.debug.nsaved; if (dump->start_stack < 0x04000000) dump->u_ssize = (0x04000000 - dump->start_stack) >> PAGE_SHIFT; dump->regs = *regs; dump->u_fpvalid = dump_fpu (regs, &dump->u_fp); } EXPORT_SYMBOL(dump_thread); /* * Shuffle the argument into the correct register before calling the * thread function. r1 is the thread argument, r2 is the pointer to * the thread function, and r3 points to the exit function. */ extern void kernel_thread_helper(void); asm( ".section .text\n" " .align\n" " .type kernel_thread_helper, #function\n" "kernel_thread_helper:\n" " mov r0, r1\n" " mov lr, r3\n" " mov pc, r2\n" " .size kernel_thread_helper, . - kernel_thread_helper\n" " .previous"); /* * 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_r1 = (unsigned long)arg; regs.ARM_r2 = (unsigned long)fn; regs.ARM_r3 = (unsigned long)do_exit; regs.ARM_pc = (unsigned long)kernel_thread_helper; regs.ARM_cpsr = SVC_MODE; 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) { unsigned long fp, lr; unsigned long stack_start, stack_end; int count = 0; if (!p || p == current || p->state == TASK_RUNNING) return 0; stack_start = (unsigned long)(p->thread_info + 1); stack_end = ((unsigned long)p->thread_info) + THREAD_SIZE; fp = thread_saved_fp(p); do { if (fp < stack_start || fp > stack_end) return 0; lr = pc_pointer (((unsigned long *)fp)[-1]); if (!in_sched_functions(lr)) return lr; fp = *(unsigned long *) (fp - 12); } while (count ++ < 16); return 0; } EXPORT_SYMBOL(get_wchan);