x86: HPET restructure hpet code for hpet force enable

Restructure and rename legacy replacement mode HPET timer support.  Just the
code structural changes and should be zero functionality change.

Signed-off-by: Venkatesh Pallipadi <venkatesh.pallipadi@intel.com>
Cc: Andi Kleen <ak@suse.de>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>

1 files changed, 83 insertions, 65 deletions

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 078dbc6d80ec..ce3bcc4334d5 100644
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -149,9 +149,9 @@ static void hpet_reserve_platform_timers(unsigned long id) { }
  */
 static unsigned long hpet_period;
 
-static void hpet_set_mode(enum clock_event_mode mode,
+static void hpet_legacy_set_mode(enum clock_event_mode mode,
                           struct clock_event_device *evt);
-static int hpet_next_event(unsigned long delta,
+static int hpet_legacy_next_event(unsigned long delta,
                            struct clock_event_device *evt);
 
 /*
@@ -160,8 +160,8 @@ static int hpet_next_event(unsigned long delta,
 static struct clock_event_device hpet_clockevent = {
         .name           = "hpet",
         .features       = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
-        .set_mode       = hpet_set_mode,
-        .set_next_event = hpet_next_event,
+        .set_mode       = hpet_legacy_set_mode,
+        .set_next_event = hpet_legacy_next_event,
         .shift          = 32,
         .irq            = 0,
 };
@@ -178,7 +178,7 @@ static void hpet_start_counter(void)
         hpet_writel(cfg, HPET_CFG);
 }
 
-static void hpet_enable_int(void)
+static void hpet_enable_legacy_int(void)
 {
         unsigned long cfg = hpet_readl(HPET_CFG);
 
@@ -187,7 +187,39 @@ static void hpet_enable_int(void)
         hpet_legacy_int_enabled = 1;
 }
 
-static void hpet_set_mode(enum clock_event_mode mode,
+static void hpet_legacy_clockevent_register(void)
+{
+        uint64_t hpet_freq;
+
+        /* Start HPET legacy interrupts */
+        hpet_enable_legacy_int();
+
+        /*
+         * The period is a femto seconds value. We need to calculate the
+         * scaled math multiplication factor for nanosecond to hpet tick
+         * conversion.
+         */
+        hpet_freq = 1000000000000000ULL;
+        do_div(hpet_freq, hpet_period);
+        hpet_clockevent.mult = div_sc((unsigned long) hpet_freq,
+                                      NSEC_PER_SEC, 32);
+        /* Calculate the min / max delta */
+        hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
+                                                           &hpet_clockevent);
+        hpet_clockevent.min_delta_ns = clockevent_delta2ns(0x30,
+                                                           &hpet_clockevent);
+
+        /*
+         * Start hpet with the boot cpu mask and make it
+         * global after the IO_APIC has been initialized.
+         */
+        hpet_clockevent.cpumask = cpumask_of_cpu(smp_processor_id());
+        clockevents_register_device(&hpet_clockevent);
+        global_clock_event = &hpet_clockevent;
+        printk(KERN_DEBUG "hpet clockevent registered\n");
+}
+
+static void hpet_legacy_set_mode(enum clock_event_mode mode,
                           struct clock_event_device *evt)
 {
         unsigned long cfg, cmp, now;
@@ -228,12 +260,12 @@ static void hpet_set_mode(enum clock_event_mode mode,
                 break;
 
         case CLOCK_EVT_MODE_RESUME:
-                hpet_enable_int();
+                hpet_enable_legacy_int();
                 break;
         }
 }
 
-static int hpet_next_event(unsigned long delta,
+static int hpet_legacy_next_event(unsigned long delta,
                            struct clock_event_device *evt)
 {
         unsigned long cnt;
@@ -273,58 +305,11 @@ static struct clocksource clocksource_hpet = {
 #endif
 };
 
-/*
- * Try to setup the HPET timer
- */
-int __init hpet_enable(void)
+static int hpet_clocksource_register(void)
 {
-        unsigned long id;
-        uint64_t hpet_freq;
         u64 tmp, start, now;
         cycle_t t1;
 
-        if (!is_hpet_capable())
-                return 0;
-
-        hpet_set_mapping();
-
-        /*
-         * Read the period and check for a sane value:
-         */
-        hpet_period = hpet_readl(HPET_PERIOD);
-        if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD)
-                goto out_nohpet;
-
-        /*
-         * The period is a femto seconds value. We need to calculate the
-         * scaled math multiplication factor for nanosecond to hpet tick
-         * conversion.
-         */
-        hpet_freq = 1000000000000000ULL;
-        do_div(hpet_freq, hpet_period);
-        hpet_clockevent.mult = div_sc((unsigned long) hpet_freq,
-                                      NSEC_PER_SEC, 32);
-        /* Calculate the min / max delta */
-        hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
-                                                           &hpet_clockevent);
-        hpet_clockevent.min_delta_ns = clockevent_delta2ns(0x30,
-                                                           &hpet_clockevent);
-
-        /*
-         * Read the HPET ID register to retrieve the IRQ routing
-         * information and the number of channels
-         */
-        id = hpet_readl(HPET_ID);
-
-#ifdef CONFIG_HPET_EMULATE_RTC
-        /*
-         * The legacy routing mode needs at least two channels, tick timer
-         * and the rtc emulation channel.
-         */
-        if (!(id & HPET_ID_NUMBER))
-                goto out_nohpet;
-#endif
-
         /* Start the counter */
         hpet_start_counter();
 
@@ -346,7 +331,7 @@ int __init hpet_enable(void)
         if (t1 == read_hpet()) {
                 printk(KERN_WARNING
                        "HPET counter not counting. HPET disabled\n");
-                goto out_nohpet;
+                return -ENODEV;
         }
 
         /* Initialize and register HPET clocksource
@@ -367,15 +352,48 @@ int __init hpet_enable(void)
 
         clocksource_register(&clocksource_hpet);
 
+        return 0;
+}
+
+/*
+ * Try to setup the HPET timer
+ */
+int __init hpet_enable(void)
+{
+        unsigned long id;
+
+        if (!is_hpet_capable())
+                return 0;
+
+        hpet_set_mapping();
+
+        /*
+         * Read the period and check for a sane value:
+         */
+        hpet_period = hpet_readl(HPET_PERIOD);
+        if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD)
+                goto out_nohpet;
+
+        /*
+         * Read the HPET ID register to retrieve the IRQ routing
+         * information and the number of channels
+         */
+        id = hpet_readl(HPET_ID);
+
+#ifdef CONFIG_HPET_EMULATE_RTC
+        /*
+         * The legacy routing mode needs at least two channels, tick timer
+         * and the rtc emulation channel.
+         */
+        if (!(id & HPET_ID_NUMBER))
+                goto out_nohpet;
+#endif
+
+        if (hpet_clocksource_register())
+                goto out_nohpet;
+
         if (id & HPET_ID_LEGSUP) {
-                hpet_enable_int();
-                /*
-                 * Start hpet with the boot cpu mask and make it
-                 * global after the IO_APIC has been initialized.
-                 */
-                hpet_clockevent.cpumask = cpumask_of_cpu(smp_processor_id());
-                clockevents_register_device(&hpet_clockevent);
-                global_clock_event = &hpet_clockevent;
+                hpet_legacy_clockevent_register();
                 return 1;
         }
         return 0;