1 files changed, 318 insertions, 0 deletions
diff --git a/arch/i386/kernel/vmiclock.c b/arch/i386/kernel/vmiclock.c
new file mode 100644
index 000000000000..26a37f8a8762
--- /dev/null
+++ b/arch/i386/kernel/vmiclock.c
@@ -0,0 +1,318 @@
+/*
+ * 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 <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.get_scheduled_cycles = vmi_get_sched_cycles */
+unsigned long long vmi_get_sched_cycles(void)
+{
+	return 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:
+		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);