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Diffstat (limited to 'arch/x86/kernel/vmiclock_32.c')
-rw-r--r--arch/x86/kernel/vmiclock_32.c320
1 files changed, 320 insertions, 0 deletions
diff --git a/arch/x86/kernel/vmiclock_32.c b/arch/x86/kernel/vmiclock_32.c
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index 000000000000..b1b5ab08b26e
--- /dev/null
+++ b/arch/x86/kernel/vmiclock_32.c
@@ -0,0 +1,320 @@
+/*
+ * VMI paravirtual timer support routines.
+ *
+ * Copyright (C) 2007, VMware, Inc.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
+ * NON INFRINGEMENT. See the GNU General Public License for more
+ * details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ *
+ */
+
+#include <linux/smp.h>
+#include <linux/interrupt.h>
+#include <linux/cpumask.h>
+#include <linux/clocksource.h>
+#include <linux/clockchips.h>
+
+#include <asm/vmi.h>
+#include <asm/vmi_time.h>
+#include <asm/arch_hooks.h>
+#include <asm/apicdef.h>
+#include <asm/apic.h>
+#include <asm/timer.h>
+#include <asm/i8253.h>
+
+#include <irq_vectors.h>
+#include "io_ports.h"
+
+#define VMI_ONESHOT (VMI_ALARM_IS_ONESHOT | VMI_CYCLES_REAL | vmi_get_alarm_wiring())
+#define VMI_PERIODIC (VMI_ALARM_IS_PERIODIC | VMI_CYCLES_REAL | vmi_get_alarm_wiring())
+
+static DEFINE_PER_CPU(struct clock_event_device, local_events);
+
+static inline u32 vmi_counter(u32 flags)
+{
+ /* Given VMI_ONESHOT or VMI_PERIODIC, return the corresponding
+ * cycle counter. */
+ return flags & VMI_ALARM_COUNTER_MASK;
+}
+
+/* paravirt_ops.get_wallclock = vmi_get_wallclock */
+unsigned long vmi_get_wallclock(void)
+{
+ unsigned long long wallclock;
+ wallclock = vmi_timer_ops.get_wallclock(); // nsec
+ (void)do_div(wallclock, 1000000000); // sec
+
+ return wallclock;
+}
+
+/* paravirt_ops.set_wallclock = vmi_set_wallclock */
+int vmi_set_wallclock(unsigned long now)
+{
+ return 0;
+}
+
+/* paravirt_ops.sched_clock = vmi_sched_clock */
+unsigned long long vmi_sched_clock(void)
+{
+ return cycles_2_ns(vmi_timer_ops.get_cycle_counter(VMI_CYCLES_AVAILABLE));
+}
+
+/* paravirt_ops.get_cpu_khz = vmi_cpu_khz */
+unsigned long vmi_cpu_khz(void)
+{
+ unsigned long long khz;
+ khz = vmi_timer_ops.get_cycle_frequency();
+ (void)do_div(khz, 1000);
+ return khz;
+}
+
+static inline unsigned int vmi_get_timer_vector(void)
+{
+#ifdef CONFIG_X86_IO_APIC
+ return FIRST_DEVICE_VECTOR;
+#else
+ return FIRST_EXTERNAL_VECTOR;
+#endif
+}
+
+/** vmi clockchip */
+#ifdef CONFIG_X86_LOCAL_APIC
+static unsigned int startup_timer_irq(unsigned int irq)
+{
+ unsigned long val = apic_read(APIC_LVTT);
+ apic_write(APIC_LVTT, vmi_get_timer_vector());
+
+ return (val & APIC_SEND_PENDING);
+}
+
+static void mask_timer_irq(unsigned int irq)
+{
+ unsigned long val = apic_read(APIC_LVTT);
+ apic_write(APIC_LVTT, val | APIC_LVT_MASKED);
+}
+
+static void unmask_timer_irq(unsigned int irq)
+{
+ unsigned long val = apic_read(APIC_LVTT);
+ apic_write(APIC_LVTT, val & ~APIC_LVT_MASKED);
+}
+
+static void ack_timer_irq(unsigned int irq)
+{
+ ack_APIC_irq();
+}
+
+static struct irq_chip vmi_chip __read_mostly = {
+ .name = "VMI-LOCAL",
+ .startup = startup_timer_irq,
+ .mask = mask_timer_irq,
+ .unmask = unmask_timer_irq,
+ .ack = ack_timer_irq
+};
+#endif
+
+/** vmi clockevent */
+#define VMI_ALARM_WIRED_IRQ0 0x00000000
+#define VMI_ALARM_WIRED_LVTT 0x00010000
+static int vmi_wiring = VMI_ALARM_WIRED_IRQ0;
+
+static inline int vmi_get_alarm_wiring(void)
+{
+ return vmi_wiring;
+}
+
+static void vmi_timer_set_mode(enum clock_event_mode mode,
+ struct clock_event_device *evt)
+{
+ cycle_t now, cycles_per_hz;
+ BUG_ON(!irqs_disabled());
+
+ switch (mode) {
+ case CLOCK_EVT_MODE_ONESHOT:
+ case CLOCK_EVT_MODE_RESUME:
+ break;
+ case CLOCK_EVT_MODE_PERIODIC:
+ cycles_per_hz = vmi_timer_ops.get_cycle_frequency();
+ (void)do_div(cycles_per_hz, HZ);
+ now = vmi_timer_ops.get_cycle_counter(vmi_counter(VMI_PERIODIC));
+ vmi_timer_ops.set_alarm(VMI_PERIODIC, now, cycles_per_hz);
+ break;
+ case CLOCK_EVT_MODE_UNUSED:
+ case CLOCK_EVT_MODE_SHUTDOWN:
+ switch (evt->mode) {
+ case CLOCK_EVT_MODE_ONESHOT:
+ vmi_timer_ops.cancel_alarm(VMI_ONESHOT);
+ break;
+ case CLOCK_EVT_MODE_PERIODIC:
+ vmi_timer_ops.cancel_alarm(VMI_PERIODIC);
+ break;
+ default:
+ break;
+ }
+ break;
+ default:
+ break;
+ }
+}
+
+static int vmi_timer_next_event(unsigned long delta,
+ struct clock_event_device *evt)
+{
+ /* Unfortunately, set_next_event interface only passes relative
+ * expiry, but we want absolute expiry. It'd be better if were
+ * were passed an aboslute expiry, since a bunch of time may
+ * have been stolen between the time the delta is computed and
+ * when we set the alarm below. */
+ cycle_t now = vmi_timer_ops.get_cycle_counter(vmi_counter(VMI_ONESHOT));
+
+ BUG_ON(evt->mode != CLOCK_EVT_MODE_ONESHOT);
+ vmi_timer_ops.set_alarm(VMI_ONESHOT, now + delta, 0);
+ return 0;
+}
+
+static struct clock_event_device vmi_clockevent = {
+ .name = "vmi-timer",
+ .features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
+ .shift = 22,
+ .set_mode = vmi_timer_set_mode,
+ .set_next_event = vmi_timer_next_event,
+ .rating = 1000,
+ .irq = 0,
+};
+
+static irqreturn_t vmi_timer_interrupt(int irq, void *dev_id)
+{
+ struct clock_event_device *evt = &__get_cpu_var(local_events);
+ evt->event_handler(evt);
+ return IRQ_HANDLED;
+}
+
+static struct irqaction vmi_clock_action = {
+ .name = "vmi-timer",
+ .handler = vmi_timer_interrupt,
+ .flags = IRQF_DISABLED | IRQF_NOBALANCING,
+ .mask = CPU_MASK_ALL,
+};
+
+static void __devinit vmi_time_init_clockevent(void)
+{
+ cycle_t cycles_per_msec;
+ struct clock_event_device *evt;
+
+ int cpu = smp_processor_id();
+ evt = &__get_cpu_var(local_events);
+
+ /* Use cycles_per_msec since div_sc params are 32-bits. */
+ cycles_per_msec = vmi_timer_ops.get_cycle_frequency();
+ (void)do_div(cycles_per_msec, 1000);
+
+ memcpy(evt, &vmi_clockevent, sizeof(*evt));
+ /* Must pick .shift such that .mult fits in 32-bits. Choosing
+ * .shift to be 22 allows 2^(32-22) cycles per nano-seconds
+ * before overflow. */
+ evt->mult = div_sc(cycles_per_msec, NSEC_PER_MSEC, evt->shift);
+ /* Upper bound is clockevent's use of ulong for cycle deltas. */
+ evt->max_delta_ns = clockevent_delta2ns(ULONG_MAX, evt);
+ evt->min_delta_ns = clockevent_delta2ns(1, evt);
+ evt->cpumask = cpumask_of_cpu(cpu);
+
+ printk(KERN_WARNING "vmi: registering clock event %s. mult=%lu shift=%u\n",
+ evt->name, evt->mult, evt->shift);
+ clockevents_register_device(evt);
+}
+
+void __init vmi_time_init(void)
+{
+ /* Disable PIT: BIOSes start PIT CH0 with 18.2hz peridic. */
+ outb_p(0x3a, PIT_MODE); /* binary, mode 5, LSB/MSB, ch 0 */
+
+ vmi_time_init_clockevent();
+ setup_irq(0, &vmi_clock_action);
+}
+
+#ifdef CONFIG_X86_LOCAL_APIC
+void __devinit vmi_time_bsp_init(void)
+{
+ /*
+ * On APIC systems, we want local timers to fire on each cpu. We do
+ * this by programming LVTT to deliver timer events to the IRQ handler
+ * for IRQ-0, since we can't re-use the APIC local timer handler
+ * without interfering with that code.
+ */
+ clockevents_notify(CLOCK_EVT_NOTIFY_SUSPEND, NULL);
+ local_irq_disable();
+#ifdef CONFIG_X86_SMP
+ /*
+ * XXX handle_percpu_irq only defined for SMP; we need to switch over
+ * to using it, since this is a local interrupt, which each CPU must
+ * handle individually without locking out or dropping simultaneous
+ * local timers on other CPUs. We also don't want to trigger the
+ * quirk workaround code for interrupts which gets invoked from
+ * handle_percpu_irq via eoi, so we use our own IRQ chip.
+ */
+ set_irq_chip_and_handler_name(0, &vmi_chip, handle_percpu_irq, "lvtt");
+#else
+ set_irq_chip_and_handler_name(0, &vmi_chip, handle_edge_irq, "lvtt");
+#endif
+ vmi_wiring = VMI_ALARM_WIRED_LVTT;
+ apic_write(APIC_LVTT, vmi_get_timer_vector());
+ local_irq_enable();
+ clockevents_notify(CLOCK_EVT_NOTIFY_RESUME, NULL);
+}
+
+void __devinit vmi_time_ap_init(void)
+{
+ vmi_time_init_clockevent();
+ apic_write(APIC_LVTT, vmi_get_timer_vector());
+}
+#endif
+
+/** vmi clocksource */
+
+static cycle_t read_real_cycles(void)
+{
+ return vmi_timer_ops.get_cycle_counter(VMI_CYCLES_REAL);
+}
+
+static struct clocksource clocksource_vmi = {
+ .name = "vmi-timer",
+ .rating = 450,
+ .read = read_real_cycles,
+ .mask = CLOCKSOURCE_MASK(64),
+ .mult = 0, /* to be set */
+ .shift = 22,
+ .flags = CLOCK_SOURCE_IS_CONTINUOUS,
+};
+
+static int __init init_vmi_clocksource(void)
+{
+ cycle_t cycles_per_msec;
+
+ if (!vmi_timer_ops.get_cycle_frequency)
+ return 0;
+ /* Use khz2mult rather than hz2mult since hz arg is only 32-bits. */
+ cycles_per_msec = vmi_timer_ops.get_cycle_frequency();
+ (void)do_div(cycles_per_msec, 1000);
+
+ /* Note that clocksource.{mult, shift} converts in the opposite direction
+ * as clockevents. */
+ clocksource_vmi.mult = clocksource_khz2mult(cycles_per_msec,
+ clocksource_vmi.shift);
+
+ printk(KERN_WARNING "vmi: registering clock source khz=%lld\n", cycles_per_msec);
+ return clocksource_register(&clocksource_vmi);
+
+}
+module_init(init_vmi_clocksource);