summaryrefslogtreecommitdiffstats
path: root/arch/arm/kernel/process.c
diff options
context:
space:
mode:
Diffstat (limited to 'arch/arm/kernel/process.c')
-rw-r--r--arch/arm/kernel/process.c394
1 files changed, 394 insertions, 0 deletions
diff --git a/arch/arm/kernel/process.c b/arch/arm/kernel/process.c
new file mode 100644
index 0000000..d3ea6fa
--- /dev/null
+++ b/arch/arm/kernel/process.c
@@ -0,0 +1,394 @@
+/*
+ * 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/slab.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/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)
+{
+ /*
+ * 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);
+
+ /*
+ * 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_idle)(void);
+EXPORT_SYMBOL(pm_idle);
+
+void (*pm_power_off)(void);
+EXPORT_SYMBOL(pm_power_off);
+
+void (*arm_pm_restart)(char str) = 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 (hlt_counter)
+ cpu_relax();
+ else {
+ local_irq_disable();
+ if (!need_resched())
+ 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;
+
+#ifdef CONFIG_HOTPLUG_CPU
+ if (cpu_is_offline(smp_processor_id())) {
+ leds_event(led_idle_start);
+ cpu_die();
+ }
+#endif
+
+ if (!idle)
+ idle = default_idle;
+ leds_event(led_idle_start);
+ tick_nohz_stop_sched_tick(1);
+ while (!need_resched())
+ idle();
+ 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 * __unused)
+{
+ arm_pm_restart(reboot_mode);
+}
+
+void __show_regs(struct pt_regs *regs)
+{
+ unsigned long flags;
+ char buf[64];
+
+ printk("CPU: %d %s (%s %.*s)\n",
+ 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();
+}
+
+/*
+ * Free current thread data structures etc..
+ */
+void exit_thread(void)
+{
+}
+
+ATOMIC_NOTIFIER_HEAD(thread_notify_head);
+
+EXPORT_SYMBOL_GPL(thread_notify_head);
+
+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)
+{
+ struct thread_info *thread = task_thread_info(dead_task);
+
+ thread_notify(THREAD_NOTIFY_RELEASE, thread);
+}
+
+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 = 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 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. 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(&regs, 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, &regs, 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)end_of_stack(p);
+ stack_end = (unsigned long)task_stack_page(p) + THREAD_SIZE;
+
+ fp = thread_saved_fp(p);
+ do {
+ if (fp < stack_start || fp > stack_end)
+ return 0;
+ lr = ((unsigned long *)fp)[-1];
+ if (!in_sched_functions(lr))
+ return lr;
+ fp = *(unsigned long *) (fp - 12);
+ } while (count ++ < 16);
+ return 0;
+}
OpenPOWER on IntegriCloud