x86: Merge the x86_32 and x86_64 cpu_idle() functions

Both functions are mostly identical.
The differences are:

- x86_32's cpu_idle() makes use of check_pgt_cache(), which is a
  nop on both x86_32 and x86_64.

- x86_64's cpu_idle() uses enter/__exit_idle/(), on x86_32 these
  function are a nop.

- In contrast to x86_32, x86_64 calls rcu_idle_enter/exit() in
  the innermost loop because idle notifications need RCU.
  Calling these function on x86_32 also in the innermost loop
  does not hurt.

So we can merge both functions.

Signed-off-by: Richard Weinberger <richard@nod.at>
Acked-by: Frederic Weisbecker <fweisbec@gmail.com>
Cc: paulmck@linux.vnet.ibm.com
Cc: josh@joshtriplett.org
Cc: tj@kernel.org
Link: http://lkml.kernel.org/r/1332709204-22496-1-git-send-email-richard@nod.at
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 0 insertions, 58 deletions

diff --git a/arch/x86/kernel/process_32.c b/arch/x86/kernel/process_32.c
index 9d7d4842bfaf..ea207c245aa4 100644
--- a/arch/x86/kernel/process_32.c
+++ b/arch/x86/kernel/process_32.c
@@ -9,7 +9,6 @@
  * This file handles the architecture-dependent parts of process handling..
  */
 
-#include <linux/stackprotector.h>
 #include <linux/cpu.h>
 #include <linux/errno.h>
 #include <linux/sched.h>
@@ -31,14 +30,12 @@
 #include <linux/kallsyms.h>
 #include <linux/ptrace.h>
 #include <linux/personality.h>
-#include <linux/tick.h>
 #include <linux/percpu.h>
 #include <linux/prctl.h>
 #include <linux/ftrace.h>
 #include <linux/uaccess.h>
 #include <linux/io.h>
 #include <linux/kdebug.h>
-#include <linux/cpuidle.h>
 
 #include <asm/pgtable.h>
 #include <asm/system.h>
@@ -58,7 +55,6 @@
 #include <asm/idle.h>
 #include <asm/syscalls.h>
 #include <asm/debugreg.h>
-#include <asm/nmi.h>
 
 asmlinkage void ret_from_fork(void) __asm__("ret_from_fork");
 
@@ -70,60 +66,6 @@ unsigned long thread_saved_pc(struct task_struct *tsk)
         return ((unsigned long *)tsk->thread.sp)[3];
 }
 
-#ifndef CONFIG_SMP
-static inline void play_dead(void)
-{
-        BUG();
-}
-#endif
-
-/*
- * The idle thread. There's no useful work to be
- * done, so just try to conserve power and have a
- * low exit latency (ie sit in a loop waiting for
- * somebody to say that they'd like to reschedule)
- */
-void cpu_idle(void)
-{
-        int cpu = smp_processor_id();
-
-        /*
-         * If we're the non-boot CPU, nothing set the stack canary up
-         * for us.  CPU0 already has it initialized but no harm in
-         * doing it again.  This is a good place for updating it, as
-         * we wont ever return from this function (so the invalid
-         * canaries already on the stack wont ever trigger).
-         */
-        boot_init_stack_canary();
-
-        current_thread_info()->status |= TS_POLLING;
-
-        /* endless idle loop with no priority at all */
-        while (1) {
-                tick_nohz_idle_enter();
-                rcu_idle_enter();
-                while (!need_resched()) {
-
-                        check_pgt_cache();
-                        rmb();
-
-                        if (cpu_is_offline(cpu))
-                                play_dead();
-
-                        local_touch_nmi();
-                        local_irq_disable();
-                        /* Don't trace irqs off for idle */
-                        stop_critical_timings();
-                        if (cpuidle_idle_call())
-                                pm_idle();
-                        start_critical_timings();
-                }
-                rcu_idle_exit();
-                tick_nohz_idle_exit();
-                schedule_preempt_disabled();
-        }
-}
-
 void __show_regs(struct pt_regs *regs, int all)
 {
         unsigned long cr0 = 0L, cr2 = 0L, cr3 = 0L, cr4 = 0L;