[PATCH] x86_64: 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>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

2 files changed, 9 insertions, 37 deletions

diff --git a/arch/x86_64/kernel/process.c b/arch/x86_64/kernel/process.c
index 3060ed97b755..c9df991150bb 100644
--- a/arch/x86_64/kernel/process.c
+++ b/arch/x86_64/kernel/process.c
@@ -55,8 +55,6 @@ asmlinkage extern void ret_from_fork(void);
 
 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);
 }
 
 /*
diff --git a/include/asm-x86_64/system.h b/include/asm-x86_64/system.h
index b34cc2ee222b..1200ea2ea12f 100644
--- a/include/asm-x86_64/system.h
+++ b/include/asm-x86_64/system.h
@@ -330,13 +330,6 @@ static inline unsigned long __cmpxchg(volatile void *ptr, unsigned long old,
 
 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