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[/] [or1k_soc_on_altera_embedded_dev_kit/] [trunk/] [linux-2.6/] [linux-2.6.24/] [arch/] [x86/] [kernel/] [vmiclock_32.c] - Rev 3
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/* * 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);