Remove enable/disable_hlt

Was only used by the floppy driver to work around some ancient
hardware bug that should never occur on any 64bit system.

Signed-off-by: Andi Kleen <ak@suse.de>

Index: linux/arch/x86_64/kernel/process.c
===================================================================
--- linux.orig/arch/x86_64/kernel/process.c
+++ linux/arch/x86_64/kernel/process.c
@@ -55,8 +55,6 @@ asmlinkage extern void ret_from_fork(voi
 
 unsigned long kernel_thread_flags = CLONE_VM | CLONE_UNTRACED;
 
-static atomic_t hlt_counter = ATOMIC_INIT(0);
-
 unsigned long boot_option_idle_override = 0;
 EXPORT_SYMBOL(boot_option_idle_override);
 
@@ -66,20 +64,6 @@ EXPORT_SYMBOL(boot_option_idle_override)
 void (*pm_idle)(void);
 static DEFINE_PER_CPU(unsigned int, cpu_idle_state);
 
-void disable_hlt(void)
-{
-	atomic_inc(&hlt_counter);
-}
-
-EXPORT_SYMBOL(disable_hlt);
-
-void enable_hlt(void)
-{
-	atomic_dec(&hlt_counter);
-}
-
-EXPORT_SYMBOL(enable_hlt);
-
 /*
  * We use this if we don't have any better
  * idle routine..
@@ -88,21 +72,16 @@ void default_idle(void)
 {
 	local_irq_enable();
 
-	if (!atomic_read(&hlt_counter)) {
-		clear_thread_flag(TIF_POLLING_NRFLAG);
-		smp_mb__after_clear_bit();
-		while (!need_resched()) {
-			local_irq_disable();
-			if (!need_resched())
-				safe_halt();
-			else
-				local_irq_enable();
-		}
-		set_thread_flag(TIF_POLLING_NRFLAG);
-	} else {
-		while (!need_resched())
-			cpu_relax();
+	clear_thread_flag(TIF_POLLING_NRFLAG);
+	smp_mb__after_clear_bit();
+	while (!need_resched()) {
+		local_irq_disable();
+		if (!need_resched())
+			safe_halt();
+		else
+			local_irq_enable();
 	}
+	set_thread_flag(TIF_POLLING_NRFLAG);
 }
 
 /*
Index: linux/include/asm-x86_64/system.h
===================================================================
--- linux.orig/include/asm-x86_64/system.h
+++ linux/include/asm-x86_64/system.h
@@ -328,13 +328,6 @@ static inline unsigned long __cmpxchg(vo
 
 void cpu_idle_wait(void);
 
-/*
- * disable hlt during certain critical i/o operations
- */
-#define HAVE_DISABLE_HLT
-void disable_hlt(void);
-void enable_hlt(void);
-
 extern unsigned long arch_align_stack(unsigned long sp);
 
 #endif