linux/arch/arm/kernel/process.c
Linus Torvalds 8546dc1d4b Merge branch 'for-linus' of git://git.linaro.org/people/rmk/linux-arm
Pull ARM updates from Russell King:
 "The major items included in here are:

   - MCPM, multi-cluster power management, part of the infrastructure
     required for ARMs big.LITTLE support.

   - A rework of the ARM KVM code to allow re-use by ARM64.

   - Error handling cleanups of the IS_ERR_OR_NULL() madness and fixes
     of that stuff for arch/arm

   - Preparatory patches for Cortex-M3 support from Uwe Kleine-König.

  There is also a set of three patches in here from Hugh/Catalin to
  address freeing of inappropriate page tables on LPAE.  You already
  have these from akpm, but they were already part of my tree at the
  time he sent them, so unfortunately they'll end up with duplicate
  commits"

* 'for-linus' of git://git.linaro.org/people/rmk/linux-arm: (77 commits)
  ARM: EXYNOS: remove unnecessary use of IS_ERR_VALUE()
  ARM: IMX: remove unnecessary use of IS_ERR_VALUE()
  ARM: OMAP: use consistent error checking
  ARM: cleanup: OMAP hwmod error checking
  ARM: 7709/1: mcpm: Add explicit AFLAGS to support v6/v7 multiplatform kernels
  ARM: 7700/2: Make cpu_init() notrace
  ARM: 7702/1: Set the page table freeing ceiling to TASK_SIZE
  ARM: 7701/1: mm: Allow arch code to control the user page table ceiling
  ARM: 7703/1: Disable preemption in broadcast_tlb*_a15_erratum()
  ARM: mcpm: provide an interface to set the SMP ops at run time
  ARM: mcpm: generic SMP secondary bringup and hotplug support
  ARM: mcpm_head.S: vlock-based first man election
  ARM: mcpm: Add baremetal voting mutexes
  ARM: mcpm: introduce helpers for platform coherency exit/setup
  ARM: mcpm: introduce the CPU/cluster power API
  ARM: multi-cluster PM: secondary kernel entry code
  ARM: cacheflush: add synchronization helpers for mixed cache state accesses
  ARM: cpu hotplug: remove majority of cache flushing from platforms
  ARM: smp: flush L1 cache in cpu_die()
  ARM: tegra: remove tegra specific cpu_disable()
  ...
2013-05-03 09:13:19 -07:00

444 lines
10 KiB
C

/*
* 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/export.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 <linux/random.h>
#include <linux/hw_breakpoint.h>
#include <linux/cpuidle.h>
#include <linux/leds.h>
#include <asm/cacheflush.h>
#include <asm/idmap.h>
#include <asm/processor.h>
#include <asm/thread_notify.h>
#include <asm/stacktrace.h>
#include <asm/mach/time.h>
#ifdef CONFIG_CC_STACKPROTECTOR
#include <linux/stackprotector.h>
unsigned long __stack_chk_guard __read_mostly;
EXPORT_SYMBOL(__stack_chk_guard);
#endif
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 call_with_stack(void (*fn)(void *), void *arg, void *sp);
typedef void (*phys_reset_t)(unsigned long);
/*
* A temporary stack to use for CPU reset. This is static so that we
* don't clobber it with the identity mapping. When running with this
* stack, any references to the current task *will not work* so you
* should really do as little as possible before jumping to your reset
* code.
*/
static u64 soft_restart_stack[16];
static void __soft_restart(void *addr)
{
phys_reset_t phys_reset;
/* Take out a flat memory mapping. */
setup_mm_for_reboot();
/* Clean and invalidate caches */
flush_cache_all();
/* Turn off caching */
cpu_proc_fin();
/* Push out any further dirty data, and ensure cache is empty */
flush_cache_all();
/* Switch to the identity mapping. */
phys_reset = (phys_reset_t)(unsigned long)virt_to_phys(cpu_reset);
phys_reset((unsigned long)addr);
/* Should never get here. */
BUG();
}
void soft_restart(unsigned long addr)
{
u64 *stack = soft_restart_stack + ARRAY_SIZE(soft_restart_stack);
/* Disable interrupts first */
local_irq_disable();
local_fiq_disable();
/* Disable the L2 if we're the last man standing. */
if (num_online_cpus() == 1)
outer_disable();
/* Change to the new stack and continue with the reset. */
call_with_stack(__soft_restart, (void *)addr, (void *)stack);
/* Should never get here. */
BUG();
}
static void null_restart(char mode, const char *cmd)
{
}
/*
* 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) = null_restart;
EXPORT_SYMBOL_GPL(arm_pm_restart);
/*
* This is our default idle handler.
*/
void (*arm_pm_idle)(void);
static void default_idle(void)
{
if (arm_pm_idle)
arm_pm_idle();
else
cpu_do_idle();
local_irq_enable();
}
void arch_cpu_idle_prepare(void)
{
local_fiq_enable();
}
void arch_cpu_idle_enter(void)
{
ledtrig_cpu(CPU_LED_IDLE_START);
#ifdef CONFIG_PL310_ERRATA_769419
wmb();
#endif
}
void arch_cpu_idle_exit(void)
{
ledtrig_cpu(CPU_LED_IDLE_END);
}
#ifdef CONFIG_HOTPLUG_CPU
void arch_cpu_idle_dead(void)
{
cpu_die();
}
#endif
/*
* Called from the core idle loop.
*/
void arch_cpu_idle(void)
{
if (cpuidle_idle_call())
default_idle();
}
static char reboot_mode = 'h';
int __init reboot_setup(char *str)
{
reboot_mode = str[0];
return 1;
}
__setup("reboot=", reboot_setup);
void machine_shutdown(void)
{
#ifdef CONFIG_SMP
smp_send_stop();
#endif
}
void machine_halt(void)
{
machine_shutdown();
local_irq_disable();
while (1);
}
void machine_power_off(void)
{
machine_shutdown();
if (pm_power_off)
pm_power_off();
}
void machine_restart(char *cmd)
{
machine_shutdown();
arm_pm_restart(reboot_mode, cmd);
/* Give a grace period for failure to restart of 1s */
mdelay(1000);
/* Whoops - the platform was unable to reboot. Tell the user! */
printk("Reboot failed -- System halted\n");
local_irq_disable();
while (1);
}
void __show_regs(struct pt_regs *regs)
{
unsigned long flags;
char buf[64];
show_regs_print_info(KERN_DEFAULT);
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");
__show_regs(regs);
dump_stack();
}
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;
flush_ptrace_hw_breakpoint(tsk);
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 thread_info *thread = task_thread_info(p);
struct pt_regs *childregs = task_pt_regs(p);
memset(&thread->cpu_context, 0, sizeof(struct cpu_context_save));
if (likely(!(p->flags & PF_KTHREAD))) {
*childregs = *current_pt_regs();
childregs->ARM_r0 = 0;
if (stack_start)
childregs->ARM_sp = stack_start;
} else {
memset(childregs, 0, sizeof(struct pt_regs));
thread->cpu_context.r4 = stk_sz;
thread->cpu_context.r5 = stack_start;
childregs->ARM_cpsr = SVC_MODE;
}
thread->cpu_context.pc = (unsigned long)ret_from_fork;
thread->cpu_context.sp = (unsigned long)childregs;
clear_ptrace_hw_breakpoint(p);
if (clone_flags & CLONE_SETTLS)
thread->tp_value = childregs->ARM_r3;
thread_notify(THREAD_NOTIFY_COPY, thread);
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);
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;
}
unsigned long arch_randomize_brk(struct mm_struct *mm)
{
unsigned long range_end = mm->brk + 0x02000000;
return randomize_range(mm->brk, range_end, 0) ? : mm->brk;
}
#ifdef CONFIG_MMU
/*
* The vectors page is always readable from user space for the
* atomic helpers and the signal restart code. Insert it into the
* gate_vma so that it is visible through ptrace and /proc/<pid>/mem.
*/
static struct vm_area_struct gate_vma = {
.vm_start = 0xffff0000,
.vm_end = 0xffff0000 + PAGE_SIZE,
.vm_flags = VM_READ | VM_EXEC | VM_MAYREAD | VM_MAYEXEC,
.vm_mm = &init_mm,
};
static int __init gate_vma_init(void)
{
gate_vma.vm_page_prot = PAGE_READONLY_EXEC;
return 0;
}
arch_initcall(gate_vma_init);
struct vm_area_struct *get_gate_vma(struct mm_struct *mm)
{
return &gate_vma;
}
int in_gate_area(struct mm_struct *mm, unsigned long addr)
{
return (addr >= gate_vma.vm_start) && (addr < gate_vma.vm_end);
}
int in_gate_area_no_mm(unsigned long addr)
{
return in_gate_area(NULL, addr);
}
const char *arch_vma_name(struct vm_area_struct *vma)
{
return (vma == &gate_vma) ? "[vectors]" : NULL;
}
#endif