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Subject[patch-mm 27/33] x86_64: convert to clock events
Finally switch to the clockevents code. Share code with i386 for
hpet and PIT.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Chris Wright <chrisw@sous-sol.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

---

arch/x86_64/Kconfig | 10 +++
arch/x86_64/kernel/Makefile | 4 +
arch/x86_64/kernel/apic.c | 90 +++++++++++++++++++----------------
arch/x86_64/kernel/i8259.c | 46 ------------------
arch/x86_64/kernel/smpboot.c | 4 -
arch/x86_64/kernel/time.c | 109 +++++--------------------------------------
include/asm-x86_64/hpet.h | 16 ------
7 files changed, 76 insertions(+), 203 deletions(-)

Index: linux-2.6.22-rc6-mm/arch/x86_64/Kconfig
===================================================================
--- linux-2.6.22-rc6-mm.orig/arch/x86_64/Kconfig 2007-07-15 17:42:51.000000000 +0200
+++ linux-2.6.22-rc6-mm/arch/x86_64/Kconfig 2007-07-15 17:43:10.000000000 +0200
@@ -28,7 +28,15 @@ config GENERIC_TIME
bool
default y

-config GENERIC_CLOCKEVENTS_MIGR
+config GENERIC_CLOCKEVENTS
+ bool
+ default y
+
+config GENERIC_CLOCKEVENTS_BROADCAST
+ bool
+ default y
+
+config NONIRQ_WAKEUP
bool
default y

Index: linux-2.6.22-rc6-mm/arch/x86_64/kernel/Makefile
===================================================================
--- linux-2.6.22-rc6-mm.orig/arch/x86_64/kernel/Makefile 2007-07-15 16:59:23.000000000 +0200
+++ linux-2.6.22-rc6-mm/arch/x86_64/kernel/Makefile 2007-07-15 17:43:10.000000000 +0200
@@ -9,7 +9,7 @@ obj-y := process.o signal.o entry.o trap
x8664_ksyms.o i387.o syscall.o vsyscall.o \
setup64.o bootflag.o e820.o reboot.o quirks.o i8237.o \
pci-dma.o pci-nommu.o alternative.o hpet.o tsc.o bugs.o \
- perfctr-watchdog.o sched-clock.o
+ perfctr-watchdog.o sched-clock.o i8253.o

obj-$(CONFIG_STACKTRACE) += stacktrace.o
obj-$(CONFIG_X86_MCE) += mce.o therm_throt.o
@@ -49,6 +49,8 @@ obj-y += pcspeaker.o

CFLAGS_vsyscall.o := $(PROFILING) -g0

+i8253-y += ../../i386/kernel/i8253.o
+hpet-y += ../../i386/kernel/hpet.o
therm_throt-y += ../../i386/kernel/cpu/mcheck/therm_throt.o
bootflag-y += ../../i386/kernel/bootflag.o
legacy_serial-y += ../../i386/kernel/legacy_serial.o
Index: linux-2.6.22-rc6-mm/arch/x86_64/kernel/apic.c
===================================================================
--- linux-2.6.22-rc6-mm.orig/arch/x86_64/kernel/apic.c 2007-07-15 17:42:51.000000000 +0200
+++ linux-2.6.22-rc6-mm/arch/x86_64/kernel/apic.c 2007-07-15 17:48:53.000000000 +0200
@@ -858,25 +858,12 @@ static void __setup_APIC_LVTT(unsigned i

static void setup_APIC_timer(void)
{
- unsigned long flags;
- int irqen;
+ struct clock_event_device *levt = &__get_cpu_var(lapic_events);

- local_irq_save(flags);
+ memcpy(levt, &lapic_clockevent, sizeof(*levt));
+ levt->cpumask = cpumask_of_cpu(smp_processor_id());

- irqen = ! cpu_isset(smp_processor_id(),
- timer_interrupt_broadcast_ipi_mask);
- __setup_APIC_LVTT(calibration_result, 0, irqen);
- /* Turn off PIT interrupt if we use APIC timer as main timer.
- Only works with the PM timer right now
- TBD fix it for HPET too. */
- if ((pmtmr_ioport != 0) &&
- smp_processor_id() == boot_cpu_id &&
- apic_runs_main_timer == 1 &&
- !cpu_isset(boot_cpu_id, timer_interrupt_broadcast_ipi_mask)) {
- stop_timer_interrupt();
- apic_runs_main_timer++;
- }
- local_irq_restore(flags);
+ clockevents_register_device(levt);
}

/*
@@ -951,18 +938,34 @@ static void __init calibrate_APIC_clock(

void __init setup_boot_APIC_clock (void)
{
+ /*
+ * The local apic timer can be disabled via the kernel commandline.
+ * Register the lapic timer as a dummy clock event source on SMP
+ * systems, so the broadcast mechanism is used. On UP systems simply
+ * ignore it.
+ */
if (disable_apic_timer) {
printk(KERN_INFO "Disabling APIC timer\n");
+ /* No broadcast on UP ! */
+ if (num_possible_cpus() > 1)
+ setup_APIC_timer();
return;
}

printk(KERN_INFO "Using local APIC timer interrupts.\n");
- using_apic_timer = 1;
-
calibrate_APIC_clock();
+
/*
- * Now set up the timer for real.
+ * If nmi_watchdog is set to IO_APIC, we need the
+ * PIT/HPET going. Otherwise register lapic as a dummy
+ * device.
*/
+ if (nmi_watchdog != NMI_IO_APIC)
+ lapic_clockevent.features &= ~CLOCK_EVT_FEAT_DUMMY;
+ else
+ printk(KERN_WARNING "APIC timer registered as dummy,"
+ " due to nmi_watchdog=1!\n");
+
setup_APIC_timer();
}

@@ -1074,22 +1077,34 @@ void setup_APIC_extended_lvt(unsigned ch

void smp_local_timer_interrupt(void)
{
- profile_tick(CPU_PROFILING);
-#ifdef CONFIG_SMP
- update_process_times(user_mode(get_irq_regs()));
-#endif
- if (apic_runs_main_timer > 1 && smp_processor_id() == boot_cpu_id)
- main_timer_handler();
+ int cpu = smp_processor_id();
+ struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
+
/*
- * We take the 'long' return path, and there every subsystem
- * grabs the appropriate locks (kernel lock/ irq lock).
+ * Normally we should not be here till LAPIC has been initialized but
+ * in some cases like kdump, its possible that there is a pending LAPIC
+ * timer interrupt from previous kernel's context and is delivered in
+ * new kernel the moment interrupts are enabled.
*
- * We might want to decouple profiling from the 'long path',
- * and do the profiling totally in assembly.
- *
- * Currently this isn't too much of an issue (performance wise),
- * we can take more than 100K local irqs per second on a 100 MHz P5.
+ * Interrupts are enabled early and LAPIC is setup much later, hence
+ * its possible that when we get here evt->event_handler is NULL.
+ * Check for event_handler being NULL and discard the interrupt as
+ * spurious.
+ */
+ if (!evt->event_handler) {
+ printk(KERN_WARNING
+ "Spurious LAPIC timer interrupt on cpu %d\n", cpu);
+ /* Switch it off */
+ lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
+ return;
+ }
+
+ /*
+ * the NMI deadlock-detector uses this.
*/
+ add_pda(apic_timer_irqs, 1);
+
+ evt->event_handler(evt);
}

/*
@@ -1105,11 +1120,6 @@ void smp_apic_timer_interrupt(struct pt_
struct pt_regs *old_regs = set_irq_regs(regs);

/*
- * the NMI deadlock-detector uses this.
- */
- add_pda(apic_timer_irqs, 1);
-
- /*
* NOTE! We'd better ACK the irq immediately,
* because timer handling can be slow.
*/
@@ -1292,7 +1302,7 @@ static __init int setup_noapictimer(char
static __init int setup_apicmaintimer(char *str)
{
apic_runs_main_timer = 1;
- nohpet = 1;
+
return 1;
}
__setup("apicmaintimer", setup_apicmaintimer);
@@ -1308,7 +1318,7 @@ static __init int setup_apicpmtimer(char
{
apic_calibrate_pmtmr = 1;
notsc_setup(NULL);
- return setup_apicmaintimer(NULL);
+ return 0;
}
__setup("apicpmtimer", setup_apicpmtimer);

Index: linux-2.6.22-rc6-mm/arch/x86_64/kernel/i8259.c
===================================================================
--- linux-2.6.22-rc6-mm.orig/arch/x86_64/kernel/i8259.c 2007-07-15 16:59:23.000000000 +0200
+++ linux-2.6.22-rc6-mm/arch/x86_64/kernel/i8259.c 2007-07-15 17:43:10.000000000 +0200
@@ -444,46 +444,6 @@ void __init init_ISA_irqs (void)
}
}

-static void setup_timer_hardware(void)
-{
- outb_p(0x34,0x43); /* binary, mode 2, LSB/MSB, ch 0 */
- udelay(10);
- outb_p(LATCH & 0xff , 0x40); /* LSB */
- udelay(10);
- outb(LATCH >> 8 , 0x40); /* MSB */
-}
-
-static int timer_resume(struct sys_device *dev)
-{
- setup_timer_hardware();
- return 0;
-}
-
-void i8254_timer_resume(void)
-{
- setup_timer_hardware();
-}
-
-static struct sysdev_class timer_sysclass = {
- set_kset_name("timer_pit"),
- .resume = timer_resume,
-};
-
-static struct sys_device device_timer = {
- .id = 0,
- .cls = &timer_sysclass,
-};
-
-static int __init init_timer_sysfs(void)
-{
- int error = sysdev_class_register(&timer_sysclass);
- if (!error)
- error = sysdev_register(&device_timer);
- return error;
-}
-
-device_initcall(init_timer_sysfs);
-
void __init init_IRQ(void)
{
int i;
@@ -533,12 +493,6 @@ void __init init_IRQ(void)
set_intr_gate(SPURIOUS_APIC_VECTOR, spurious_interrupt);
set_intr_gate(ERROR_APIC_VECTOR, error_interrupt);

- /*
- * Set the clock to HZ Hz, we already have a valid
- * vector now:
- */
- setup_timer_hardware();
-
if (!acpi_ioapic)
setup_irq(2, &irq2);
}
Index: linux-2.6.22-rc6-mm/arch/x86_64/kernel/smpboot.c
===================================================================
--- linux-2.6.22-rc6-mm.orig/arch/x86_64/kernel/smpboot.c 2007-07-15 16:59:23.000000000 +0200
+++ linux-2.6.22-rc6-mm/arch/x86_64/kernel/smpboot.c 2007-07-15 17:43:10.000000000 +0200
@@ -223,8 +223,6 @@ void __cpuinit smp_callin(void)
local_irq_disable();
Dprintk("Stack at about %p\n",&cpuid);

- disable_APIC_timer();
-
/*
* Save our processor parameters
*/
@@ -348,8 +346,6 @@ void __cpuinit start_secondary(void)
enable_8259A_irq(0);
}

- enable_APIC_timer();
-
/*
* The sibling maps must be set before turing the online map on for
* this cpu
Index: linux-2.6.22-rc6-mm/arch/x86_64/kernel/time.c
===================================================================
--- linux-2.6.22-rc6-mm.orig/arch/x86_64/kernel/time.c 2007-07-15 17:39:28.000000000 +0200
+++ linux-2.6.22-rc6-mm/arch/x86_64/kernel/time.c 2007-07-15 17:48:53.000000000 +0200
@@ -28,6 +28,8 @@
#include <linux/cpu.h>
#include <linux/kallsyms.h>
#include <linux/acpi.h>
+#include <linux/clockchips.h>
+
#ifdef CONFIG_ACPI
#include <acpi/achware.h> /* for PM timer frequency */
#include <acpi/acpi_bus.h>
@@ -46,12 +48,8 @@
#include <asm/nmi.h>
#include <asm/vgtod.h>

-static char *timename = NULL;
-
DEFINE_SPINLOCK(rtc_lock);
EXPORT_SYMBOL(rtc_lock);
-DEFINE_SPINLOCK(i8253_lock);
-EXPORT_SYMBOL(i8253_lock);

volatile unsigned long __jiffies __section_jiffies = INITIAL_JIFFIES;

@@ -194,6 +192,13 @@ static irqreturn_t timer_interrupt(int i
return IRQ_HANDLED;
}

+static irqreturn_t timer_event_interrupt(int irq, void *dev_id)
+{
+ global_clock_event->event_handler(global_clock_event);
+
+ return IRQ_HANDLED;
+}
+
unsigned long read_persistent_clock(void)
{
unsigned int year, mon, day, hour, min, sec;
@@ -291,63 +296,19 @@ static unsigned int __init tsc_calibrate
return pmc_now * tsc_khz / (tsc_now - tsc_start);
}

-static void __pit_init(int val, u8 mode)
-{
- unsigned long flags;
-
- spin_lock_irqsave(&i8253_lock, flags);
- outb_p(mode, PIT_MODE);
- outb_p(val & 0xff, PIT_CH0); /* LSB */
- outb_p(val >> 8, PIT_CH0); /* MSB */
- spin_unlock_irqrestore(&i8253_lock, flags);
-}
-
-void __init pit_init(void)
-{
- __pit_init(LATCH, 0x34); /* binary, mode 2, LSB/MSB, ch 0 */
-}
-
-void pit_stop_interrupt(void)
-{
- __pit_init(0, 0x30); /* mode 0 */
-}
-
-void stop_timer_interrupt(void)
-{
- char *name;
- if (hpet_address) {
- name = "HPET";
- hpet_timer_stop_set_go(0);
- } else {
- name = "PIT";
- pit_stop_interrupt();
- }
- printk(KERN_INFO "timer: %s interrupt stopped.\n", name);
-}
-
static struct irqaction irq0 = {
- .handler = timer_interrupt,
- .flags = IRQF_DISABLED | IRQF_IRQPOLL,
+ .handler = timer_event_interrupt,
+ .flags = IRQF_DISABLED | IRQF_IRQPOLL | IRQF_NOBALANCING,
.mask = CPU_MASK_NONE,
.name = "timer"
};

void __init time_init(void)
{
- if (nohpet)
- hpet_address = 0;
-
- if (hpet_arch_init())
- hpet_address = 0;
+ if (!hpet_enable())
+ setup_pit_timer();

- if (hpet_use_timer) {
- /* set tick_nsec to use the proper rate for HPET */
- tick_nsec = TICK_NSEC_HPET;
- timename = "HPET";
- } else {
- pit_init();
- timename = "PIT";
- }
+ setup_irq(0, &irq0);

tsc_calibrate();

@@ -368,46 +329,4 @@ void __init time_init(void)
printk(KERN_INFO "time.c: Detected %d.%03d MHz processor.\n",
cpu_khz / 1000, cpu_khz % 1000);
init_tsc_clocksource();
-
- setup_irq(0, &irq0);
-}
-
-/*
- * sysfs support for the timer.
- */
-
-static int timer_suspend(struct sys_device *dev, pm_message_t state)
-{
- return 0;
}
-
-static int timer_resume(struct sys_device *dev)
-{
- if (hpet_address)
- hpet_reenable();
- else
- i8254_timer_resume();
- return 0;
-}
-
-static struct sysdev_class timer_sysclass = {
- .resume = timer_resume,
- .suspend = timer_suspend,
- set_kset_name("timer"),
-};
-
-/* XXX this sysfs stuff should probably go elsewhere later -john */
-static struct sys_device device_timer = {
- .id = 0,
- .cls = &timer_sysclass,
-};
-
-static int time_init_device(void)
-{
- int error = sysdev_class_register(&timer_sysclass);
- if (!error)
- error = sysdev_register(&device_timer);
- return error;
-}
-
-device_initcall(time_init_device);
Index: linux-2.6.22-rc6-mm/include/asm-x86_64/hpet.h
===================================================================
--- linux-2.6.22-rc6-mm.orig/include/asm-x86_64/hpet.h 2007-07-15 17:33:23.000000000 +0200
+++ linux-2.6.22-rc6-mm/include/asm-x86_64/hpet.h 2007-07-15 17:43:10.000000000 +0200
@@ -1,18 +1,2 @@
-#ifndef _ASM_X8664_HPET_H
-#define _ASM_X8664_HPET_H 1

#include <asm-i386/hpet.h>
-
-#define HPET_TICK_RATE (HZ * 100000UL)
-
-extern int hpet_rtc_timer_init(void);
-extern int hpet_arch_init(void);
-extern int hpet_timer_stop_set_go(unsigned long tick);
-extern int hpet_reenable(void);
-extern unsigned int hpet_calibrate_tsc(void);
-
-extern int hpet_use_timer;
-extern unsigned long hpet_period;
-extern unsigned long hpet_tick;
-
-#endif
--

-
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