tile: Use generic idle loop

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Paul McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Reviewed-by: Cc: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com>
Cc: Magnus Damm <magnus.damm@gmail.com>
Acked-by: Chris Metcalf <cmetcalf@tilera.com>
Link: http://lkml.kernel.org/r/20130321215235.348460344@linutronix.de
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

3 files changed, 11 insertions, 57 deletions

diff --git a/arch/tile/Kconfig b/arch/tile/Kconfig
index 25877aebc685..85b2edeade31 100644
--- a/arch/tile/Kconfig
+++ b/arch/tile/Kconfig
@@ -22,6 +22,7 @@ config TILE
         select ARCH_HAVE_NMI_SAFE_CMPXCHG
         select GENERIC_CLOCKEVENTS
         select MODULES_USE_ELF_RELA
+        select GENERIC_IDLE_LOOP
 
 # FIXME: investigate whether we need/want these options.
 #       select HAVE_IOREMAP_PROT
diff --git a/arch/tile/kernel/process.c b/arch/tile/kernel/process.c
index caf93ae11793..80b2a18deb87 100644
--- a/arch/tile/kernel/process.c
+++ b/arch/tile/kernel/process.c
@@ -40,13 +40,11 @@
 #include <arch/abi.h>
 #include <arch/sim_def.h>
 
-
 /*
  * Use the (x86) "idle=poll" option to prefer low latency when leaving the
  * idle loop over low power while in the idle loop, e.g. if we have
  * one thread per core and we want to get threads out of futex waits fast.
  */
-static int no_idle_nap;
 static int __init idle_setup(char *str)
 {
         if (!str)
@@ -54,64 +52,19 @@ static int __init idle_setup(char *str)
 
         if (!strcmp(str, "poll")) {
                 pr_info("using polling idle threads.\n");
-                no_idle_nap = 1;
-        } else if (!strcmp(str, "halt"))
-                no_idle_nap = 0;
-        else
-                return -1;
-
-        return 0;
+                cpu_idle_poll_ctrl(true);
+                return 0;
+        } else if (!strcmp(str, "halt")) {
+                return 0;
+        }
+        return -1;
 }
 early_param("idle", idle_setup);
 
-/*
- * 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)
+void arch_cpu_idle(void)
 {
-        int cpu = smp_processor_id();
-
-
-        current_thread_info()->status |= TS_POLLING;
-
-        if (no_idle_nap) {
-                while (1) {
-                        while (!need_resched())
-                                cpu_relax();
-                        schedule();
-                }
-        }
-
-        /* endless idle loop with no priority at all */
-        while (1) {
-                tick_nohz_idle_enter();
-                rcu_idle_enter();
-                while (!need_resched()) {
-                        if (cpu_is_offline(cpu))
-                                BUG();  /* no HOTPLUG_CPU */
-
-                        local_irq_disable();
-                        __get_cpu_var(irq_stat).idle_timestamp = jiffies;
-                        current_thread_info()->status &= ~TS_POLLING;
-                        /*
-                         * TS_POLLING-cleared state must be visible before we
-                         * test NEED_RESCHED:
-                         */
-                        smp_mb();
-
-                        if (!need_resched())
-                                _cpu_idle();
-                        else
-                                local_irq_enable();
-                        current_thread_info()->status |= TS_POLLING;
-                }
-                rcu_idle_exit();
-                tick_nohz_idle_exit();
-                schedule_preempt_disabled();
-        }
+        __get_cpu_var(irq_stat).idle_timestamp = jiffies;
+        _cpu_idle();
 }
 
 /*
diff --git a/arch/tile/kernel/smpboot.c b/arch/tile/kernel/smpboot.c
index 11c0190bb096..44bab29bf2f3 100644
--- a/arch/tile/kernel/smpboot.c
+++ b/arch/tile/kernel/smpboot.c
@@ -207,7 +207,7 @@ void __cpuinit online_secondary(void)
         /* Set up tile-timer clock-event device on this cpu */
         setup_tile_timer();
 
-        cpu_idle();
+        cpu_startup_entry(CPUHP_ONLINE);
 }
 
 int __cpuinit __cpu_up(unsigned int cpu, struct task_struct *tidle)