x86/hpet: Wrap legacy clockevent in hpet_channel

For HPET channel 0 there exist two clockevent structures right now:
  - the static hpet_clockevent
  - the clockevent in channel 0 storage

The goal is to use the clockevent in the channel storage, remove the static
variable and share code with the MSI implementation.

As a first step wrap the legacy clockevent into a hpet_channel struct and
convert the users.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Ingo Molnar <mingo@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Ricardo Neri <ricardo.neri-calderon@linux.intel.com>
Cc: Ashok Raj <ashok.raj@intel.com>
Cc: Andi Kleen <andi.kleen@intel.com>
Cc: Suravee Suthikulpanit <Suravee.Suthikulpanit@amd.com>
Cc: Stephane Eranian <eranian@google.com>
Cc: Ravi Shankar <ravi.v.shankar@intel.com>
Link: https://lkml.kernel.org/r/20190623132436.368141247@linutronix.de

diff --git a/arch/x86/kernel/hpet.c b/arch/x86/kernel/hpet.c
index 985a2246d20c3cec79df3594be55d4af10d303fd..19e3ac81c3b97bbf687ac6219c39c8ddfdcd51f2 100644 (file)
--- a/arch/x86/kernel/hpet.c
+++ b/arch/x86/kernel/hpet.c
@@ -66,7 +66,7 @@ bool                                  boot_hpet_disable;
 bool                                   hpet_force_user;
 static bool                            hpet_verbose;
 
-static struct clock_event_device       hpet_clockevent;
+static struct hpet_channel             hpet_channel0;
 
 static inline
 struct hpet_channel *clockevent_to_channel(struct clock_event_device *evt)
@@ -294,7 +294,7 @@ static void hpet_enable_legacy_int(void)
        hpet_legacy_int_enabled = true;
 }
 
-static void hpet_legacy_clockevent_register(void)
+static void hpet_legacy_clockevent_register(struct hpet_channel *hc)
 {
        /* Start HPET legacy interrupts */
        hpet_enable_legacy_int();
@@ -303,10 +303,10 @@ static void hpet_legacy_clockevent_register(void)
         * Start HPET with the boot CPU's cpumask and make it global after
         * the IO_APIC has been initialized.
         */
-       hpet_clockevent.cpumask = cpumask_of(boot_cpu_data.cpu_index);
-       clockevents_config_and_register(&hpet_clockevent, hpet_freq,
+       hc->evt.cpumask = cpumask_of(boot_cpu_data.cpu_index);
+       clockevents_config_and_register(&hc->evt, hpet_freq,
                                        HPET_MIN_PROG_DELTA, 0x7FFFFFFF);
-       global_clock_event = &hpet_clockevent;
+       global_clock_event = &hc->evt;
        pr_debug("Clockevent registered\n");
 }
 
@@ -433,19 +433,21 @@ static int hpet_legacy_next_event(unsigned long delta,
 }
 
 /*
- * The HPET clock event device
+ * The HPET clock event device wrapped in a channel for conversion
  */
-static struct clock_event_device hpet_clockevent = {
-       .name                   = "hpet",
-       .features               = CLOCK_EVT_FEAT_PERIODIC |
-                                 CLOCK_EVT_FEAT_ONESHOT,
-       .set_state_periodic     = hpet_legacy_set_periodic,
-       .set_state_oneshot      = hpet_legacy_set_oneshot,
-       .set_state_shutdown     = hpet_legacy_shutdown,
-       .tick_resume            = hpet_legacy_resume,
-       .set_next_event         = hpet_legacy_next_event,
-       .irq                    = 0,
-       .rating                 = 50,
+static struct hpet_channel hpet_channel0 = {
+       .evt = {
+               .name                   = "hpet",
+               .features               = CLOCK_EVT_FEAT_PERIODIC |
+                                         CLOCK_EVT_FEAT_ONESHOT,
+               .set_state_periodic     = hpet_legacy_set_periodic,
+               .set_state_oneshot      = hpet_legacy_set_oneshot,
+               .set_state_shutdown     = hpet_legacy_shutdown,
+               .tick_resume            = hpet_legacy_resume,
+               .set_next_event         = hpet_legacy_next_event,
+               .irq                    = 0,
+               .rating                 = 50,
+       }
 };
 
 /*
@@ -916,7 +918,7 @@ int __init hpet_enable(void)
        clocksource_register_hz(&clocksource_hpet, (u32)hpet_freq);
 
        if (id & HPET_ID_LEGSUP) {
-               hpet_legacy_clockevent_register();
+               hpet_legacy_clockevent_register(&hpet_channel0);
                hpet_base.channels[0].mode = HPET_MODE_LEGACY;
                if (IS_ENABLED(CONFIG_HPET_EMULATE_RTC))
                        hpet_base.channels[1].mode = HPET_MODE_LEGACY;
@@ -1101,10 +1103,11 @@ int hpet_rtc_timer_init(void)
                return 0;
 
        if (!hpet_default_delta) {
+               struct clock_event_device *evt = &hpet_channel0.evt;
                uint64_t clc;
 
-               clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
-               clc >>= hpet_clockevent.shift + DEFAULT_RTC_SHIFT;
+               clc = (uint64_t) evt->mult * NSEC_PER_SEC;
+               clc >>= evt->shift + DEFAULT_RTC_SHIFT;
                hpet_default_delta = clc;
        }
 
@@ -1198,9 +1201,11 @@ int hpet_set_periodic_freq(unsigned long freq)
        if (freq <= DEFAULT_RTC_INT_FREQ) {
                hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq;
        } else {
-               clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
+               struct clock_event_device *evt = &hpet_channel0.evt;
+
+               clc = (uint64_t) evt->mult * NSEC_PER_SEC;
                do_div(clc, freq);
-               clc >>= hpet_clockevent.shift;
+               clc >>= evt->shift;
                hpet_pie_delta = clc;
                hpet_pie_limit = 0;
        }