[Blackfin] arch: initial generic time and clock sources
This patch enables Hight-Res Timers and tickless kernel
Signed-off-by: Vitja Makarov <vitja.makarov@gmail.com>
Signed-off-by: Michael Hennerich <michael.hennerich@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>
diff --git a/arch/blackfin/kernel/process.c b/arch/blackfin/kernel/process.c
index 6b8459c6..6dedb2d 100644
--- a/arch/blackfin/kernel/process.c
+++ b/arch/blackfin/kernel/process.c
@@ -32,6 +32,8 @@
#include <linux/unistd.h>
#include <linux/user.h>
#include <linux/uaccess.h>
+#include <linux/sched.h>
+#include <linux/tick.h>
#include <linux/fs.h>
#include <linux/err.h>
@@ -69,33 +71,44 @@
* The idle loop on BFIN
*/
#ifdef CONFIG_IDLE_L1
-void default_idle(void)__attribute__((l1_text));
+static void default_idle(void)__attribute__((l1_text));
void cpu_idle(void)__attribute__((l1_text));
#endif
-void default_idle(void)
+/*
+ * This is our default idle handler. We need to disable
+ * interrupts here to ensure we don't miss a wakeup call.
+ */
+static void default_idle(void)
{
- while (!need_resched()) {
- local_irq_disable();
- if (likely(!need_resched()))
- idle_with_irq_disabled();
- local_irq_enable();
- }
+ local_irq_disable();
+ if (!need_resched())
+ idle_with_irq_disabled();
+
+ local_irq_enable();
}
-void (*idle)(void) = default_idle;
-
/*
- * 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)
+ * The idle thread. We try to conserve power, while trying to keep
+ * overall latency low. The architecture specific idle is passed
+ * a value to indicate the level of "idleness" of the system.
*/
void cpu_idle(void)
{
/* endless idle loop with no priority at all */
while (1) {
- idle();
+ void (*idle)(void) = pm_idle;
+
+#ifdef CONFIG_HOTPLUG_CPU
+ if (cpu_is_offline(smp_processor_id()))
+ cpu_die();
+#endif
+ if (!idle)
+ idle = default_idle;
+ tick_nohz_stop_sched_tick();
+ while (!need_resched())
+ idle();
+ tick_nohz_restart_sched_tick();
preempt_enable_no_resched();
schedule();
preempt_disable();