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);