diff options
Diffstat (limited to 'arch/i386/kernel/vmitime.c')
| -rw-r--r-- | arch/i386/kernel/vmitime.c | 482 |
1 files changed, 0 insertions, 482 deletions
diff --git a/arch/i386/kernel/vmitime.c b/arch/i386/kernel/vmitime.c deleted file mode 100644 index 9dfb17739b67..000000000000 --- a/arch/i386/kernel/vmitime.c +++ /dev/null @@ -1,482 +0,0 @@ -/* - * VMI paravirtual timer support routines. - * - * Copyright (C) 2005, 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. - * - * Send feedback to dhecht@vmware.com - * - */ - -/* - * Portions of this code from arch/i386/kernel/timers/timer_tsc.c. - * Portions of the CONFIG_NO_IDLE_HZ code from arch/s390/kernel/time.c. - * See comments there for proper credits. - */ - -#include <linux/spinlock.h> -#include <linux/init.h> -#include <linux/errno.h> -#include <linux/jiffies.h> -#include <linux/interrupt.h> -#include <linux/kernel_stat.h> -#include <linux/rcupdate.h> -#include <linux/clocksource.h> - -#include <asm/timer.h> -#include <asm/io.h> -#include <asm/apic.h> -#include <asm/div64.h> -#include <asm/timer.h> -#include <asm/desc.h> - -#include <asm/vmi.h> -#include <asm/vmi_time.h> - -#include <mach_timer.h> -#include <io_ports.h> - -#ifdef CONFIG_X86_LOCAL_APIC -#define VMI_ALARM_WIRING VMI_ALARM_WIRED_LVTT -#else -#define VMI_ALARM_WIRING VMI_ALARM_WIRED_IRQ0 -#endif - -/* Cached VMI operations */ -struct vmi_timer_ops vmi_timer_ops; - -#ifdef CONFIG_NO_IDLE_HZ - -/* /proc/sys/kernel/hz_timer state. */ -int sysctl_hz_timer; - -/* Some stats */ -static DEFINE_PER_CPU(unsigned long, vmi_idle_no_hz_irqs); -static DEFINE_PER_CPU(unsigned long, vmi_idle_no_hz_jiffies); -static DEFINE_PER_CPU(unsigned long, idle_start_jiffies); - -#endif /* CONFIG_NO_IDLE_HZ */ - -/* Number of alarms per second. By default this is CONFIG_VMI_ALARM_HZ. */ -static int alarm_hz = CONFIG_VMI_ALARM_HZ; - -/* Cache of the value get_cycle_frequency / HZ. */ -static signed long long cycles_per_jiffy; - -/* Cache of the value get_cycle_frequency / alarm_hz. */ -static signed long long cycles_per_alarm; - -/* The number of cycles accounted for by the 'jiffies'/'xtime' count. - * Protected by xtime_lock. */ -static unsigned long long real_cycles_accounted_system; - -/* The number of cycles accounted for by update_process_times(), per cpu. */ -static DEFINE_PER_CPU(unsigned long long, process_times_cycles_accounted_cpu); - -/* The number of stolen cycles accounted, per cpu. */ -static DEFINE_PER_CPU(unsigned long long, stolen_cycles_accounted_cpu); - -/* Clock source. */ -static cycle_t read_real_cycles(void) -{ - return vmi_timer_ops.get_cycle_counter(VMI_CYCLES_REAL); -} - -static cycle_t read_available_cycles(void) -{ - return vmi_timer_ops.get_cycle_counter(VMI_CYCLES_AVAILABLE); -} - -#if 0 -static cycle_t read_stolen_cycles(void) -{ - return vmi_timer_ops.get_cycle_counter(VMI_CYCLES_STOLEN); -} -#endif /* 0 */ - -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, -}; - - -/* Timer interrupt handler. */ -static irqreturn_t vmi_timer_interrupt(int irq, void *dev_id); - -static struct irqaction vmi_timer_irq = { - .handler = vmi_timer_interrupt, - .flags = IRQF_DISABLED, - .mask = CPU_MASK_NONE, - .name = "VMI-alarm", -}; - -/* Alarm rate */ -static int __init vmi_timer_alarm_rate_setup(char* str) -{ - int alarm_rate; - if (get_option(&str, &alarm_rate) == 1 && alarm_rate > 0) { - alarm_hz = alarm_rate; - printk(KERN_WARNING "VMI timer alarm HZ set to %d\n", alarm_hz); - } - return 1; -} -__setup("vmi_timer_alarm_hz=", vmi_timer_alarm_rate_setup); - - -/* Initialization */ -static void vmi_get_wallclock_ts(struct timespec *ts) -{ - unsigned long long wallclock; - wallclock = vmi_timer_ops.get_wallclock(); // nsec units - ts->tv_nsec = do_div(wallclock, 1000000000); - ts->tv_sec = wallclock; -} - -unsigned long vmi_get_wallclock(void) -{ - struct timespec ts; - vmi_get_wallclock_ts(&ts); - return ts.tv_sec; -} - -int vmi_set_wallclock(unsigned long now) -{ - return -1; -} - -unsigned long long vmi_get_sched_cycles(void) -{ - return read_available_cycles(); -} - -unsigned long vmi_cpu_khz(void) -{ - unsigned long long khz; - - khz = vmi_timer_ops.get_cycle_frequency(); - (void)do_div(khz, 1000); - return khz; -} - -void __init vmi_time_init(void) -{ - unsigned long long cycles_per_sec, cycles_per_msec; - unsigned long flags; - - local_irq_save(flags); - setup_irq(0, &vmi_timer_irq); -#ifdef CONFIG_X86_LOCAL_APIC - set_intr_gate(LOCAL_TIMER_VECTOR, apic_vmi_timer_interrupt); -#endif - - real_cycles_accounted_system = read_real_cycles(); - per_cpu(process_times_cycles_accounted_cpu, 0) = read_available_cycles(); - - cycles_per_sec = vmi_timer_ops.get_cycle_frequency(); - cycles_per_jiffy = cycles_per_sec; - (void)do_div(cycles_per_jiffy, HZ); - cycles_per_alarm = cycles_per_sec; - (void)do_div(cycles_per_alarm, alarm_hz); - cycles_per_msec = cycles_per_sec; - (void)do_div(cycles_per_msec, 1000); - - printk(KERN_WARNING "VMI timer cycles/sec = %llu ; cycles/jiffy = %llu ;" - "cycles/alarm = %llu\n", cycles_per_sec, cycles_per_jiffy, - cycles_per_alarm); - - clocksource_vmi.mult = clocksource_khz2mult(cycles_per_msec, - clocksource_vmi.shift); - if (clocksource_register(&clocksource_vmi)) - printk(KERN_WARNING "Error registering VMITIME clocksource."); - - /* Disable PIT. */ - outb_p(0x3a, PIT_MODE); /* binary, mode 5, LSB/MSB, ch 0 */ - - /* schedule the alarm. do this in phase with process_times_cycles_accounted_cpu - * reduce the latency calling update_process_times. */ - vmi_timer_ops.set_alarm( - VMI_ALARM_WIRED_IRQ0 | VMI_ALARM_IS_PERIODIC | VMI_CYCLES_AVAILABLE, - per_cpu(process_times_cycles_accounted_cpu, 0) + cycles_per_alarm, - cycles_per_alarm); - - local_irq_restore(flags); -} - -#ifdef CONFIG_X86_LOCAL_APIC - -void __init vmi_timer_setup_boot_alarm(void) -{ - local_irq_disable(); - - /* Route the interrupt to the correct vector. */ - apic_write_around(APIC_LVTT, LOCAL_TIMER_VECTOR); - - /* Cancel the IRQ0 wired alarm, and setup the LVTT alarm. */ - vmi_timer_ops.cancel_alarm(VMI_CYCLES_AVAILABLE); - vmi_timer_ops.set_alarm( - VMI_ALARM_WIRED_LVTT | VMI_ALARM_IS_PERIODIC | VMI_CYCLES_AVAILABLE, - per_cpu(process_times_cycles_accounted_cpu, 0) + cycles_per_alarm, - cycles_per_alarm); - local_irq_enable(); -} - -/* Initialize the time accounting variables for an AP on an SMP system. - * Also, set the local alarm for the AP. */ -void __devinit vmi_timer_setup_secondary_alarm(void) -{ - int cpu = smp_processor_id(); - - /* Route the interrupt to the correct vector. */ - apic_write_around(APIC_LVTT, LOCAL_TIMER_VECTOR); - - per_cpu(process_times_cycles_accounted_cpu, cpu) = read_available_cycles(); - - vmi_timer_ops.set_alarm( - VMI_ALARM_WIRED_LVTT | VMI_ALARM_IS_PERIODIC | VMI_CYCLES_AVAILABLE, - per_cpu(process_times_cycles_accounted_cpu, cpu) + cycles_per_alarm, - cycles_per_alarm); -} - -#endif - -/* Update system wide (real) time accounting (e.g. jiffies, xtime). */ -static void vmi_account_real_cycles(unsigned long long cur_real_cycles) -{ - long long cycles_not_accounted; - - write_seqlock(&xtime_lock); - - cycles_not_accounted = cur_real_cycles - real_cycles_accounted_system; - while (cycles_not_accounted >= cycles_per_jiffy) { - /* systems wide jiffies. */ - do_timer(1); - - cycles_not_accounted -= cycles_per_jiffy; - real_cycles_accounted_system += cycles_per_jiffy; - } - - write_sequnlock(&xtime_lock); -} - -/* Update per-cpu process times. */ -static void vmi_account_process_times_cycles(struct pt_regs *regs, int cpu, - unsigned long long cur_process_times_cycles) -{ - long long cycles_not_accounted; - cycles_not_accounted = cur_process_times_cycles - - per_cpu(process_times_cycles_accounted_cpu, cpu); - - while (cycles_not_accounted >= cycles_per_jiffy) { - /* Account time to the current process. This includes - * calling into the scheduler to decrement the timeslice - * and possibly reschedule.*/ - update_process_times(user_mode(regs)); - /* XXX handle /proc/profile multiplier. */ - profile_tick(CPU_PROFILING); - - cycles_not_accounted -= cycles_per_jiffy; - per_cpu(process_times_cycles_accounted_cpu, cpu) += cycles_per_jiffy; - } -} - -#ifdef CONFIG_NO_IDLE_HZ -/* Update per-cpu idle times. Used when a no-hz halt is ended. */ -static void vmi_account_no_hz_idle_cycles(int cpu, - unsigned long long cur_process_times_cycles) -{ - long long cycles_not_accounted; - unsigned long no_idle_hz_jiffies = 0; - - cycles_not_accounted = cur_process_times_cycles - - per_cpu(process_times_cycles_accounted_cpu, cpu); - - while (cycles_not_accounted >= cycles_per_jiffy) { - no_idle_hz_jiffies++; - cycles_not_accounted -= cycles_per_jiffy; - per_cpu(process_times_cycles_accounted_cpu, cpu) += cycles_per_jiffy; - } - /* Account time to the idle process. */ - account_steal_time(idle_task(cpu), jiffies_to_cputime(no_idle_hz_jiffies)); -} -#endif - -/* Update per-cpu stolen time. */ -static void vmi_account_stolen_cycles(int cpu, - unsigned long long cur_real_cycles, - unsigned long long cur_avail_cycles) -{ - long long stolen_cycles_not_accounted; - unsigned long stolen_jiffies = 0; - - if (cur_real_cycles < cur_avail_cycles) - return; - - stolen_cycles_not_accounted = cur_real_cycles - cur_avail_cycles - - per_cpu(stolen_cycles_accounted_cpu, cpu); - - while (stolen_cycles_not_accounted >= cycles_per_jiffy) { - stolen_jiffies++; - stolen_cycles_not_accounted -= cycles_per_jiffy; - per_cpu(stolen_cycles_accounted_cpu, cpu) += cycles_per_jiffy; - } - /* HACK: pass NULL to force time onto cpustat->steal. */ - account_steal_time(NULL, jiffies_to_cputime(stolen_jiffies)); -} - -/* Body of either IRQ0 interrupt handler (UP no local-APIC) or - * local-APIC LVTT interrupt handler (UP & local-APIC or SMP). */ -static void vmi_local_timer_interrupt(int cpu) -{ - unsigned long long cur_real_cycles, cur_process_times_cycles; - - cur_real_cycles = read_real_cycles(); - cur_process_times_cycles = read_available_cycles(); - /* Update system wide (real) time state (xtime, jiffies). */ - vmi_account_real_cycles(cur_real_cycles); - /* Update per-cpu process times. */ - vmi_account_process_times_cycles(get_irq_regs(), cpu, cur_process_times_cycles); - /* Update time stolen from this cpu by the hypervisor. */ - vmi_account_stolen_cycles(cpu, cur_real_cycles, cur_process_times_cycles); -} - -#ifdef CONFIG_NO_IDLE_HZ - -/* Must be called only from idle loop, with interrupts disabled. */ -int vmi_stop_hz_timer(void) -{ - /* Note that cpu_set, cpu_clear are (SMP safe) atomic on x86. */ - - unsigned long seq, next; - unsigned long long real_cycles_expiry; - int cpu = smp_processor_id(); - - BUG_ON(!irqs_disabled()); - if (sysctl_hz_timer != 0) - return 0; - - cpu_set(cpu, nohz_cpu_mask); - smp_mb(); - - if (rcu_needs_cpu(cpu) || local_softirq_pending() || - (next = next_timer_interrupt(), - time_before_eq(next, jiffies + HZ/CONFIG_VMI_ALARM_HZ))) { - cpu_clear(cpu, nohz_cpu_mask); - return 0; - } - - /* Convert jiffies to the real cycle counter. */ - do { - seq = read_seqbegin(&xtime_lock); - real_cycles_expiry = real_cycles_accounted_system + - (long)(next - jiffies) * cycles_per_jiffy; - } while (read_seqretry(&xtime_lock, seq)); - - /* This cpu is going idle. Disable the periodic alarm. */ - vmi_timer_ops.cancel_alarm(VMI_CYCLES_AVAILABLE); - per_cpu(idle_start_jiffies, cpu) = jiffies; - /* Set the real time alarm to expire at the next event. */ - vmi_timer_ops.set_alarm( - VMI_ALARM_WIRING | VMI_ALARM_IS_ONESHOT | VMI_CYCLES_REAL, - real_cycles_expiry, 0); - return 1; -} - -static void vmi_reenable_hz_timer(int cpu) -{ - /* For /proc/vmi/info idle_hz stat. */ - per_cpu(vmi_idle_no_hz_jiffies, cpu) += jiffies - per_cpu(idle_start_jiffies, cpu); - per_cpu(vmi_idle_no_hz_irqs, cpu)++; - - /* Don't bother explicitly cancelling the one-shot alarm -- at - * worse we will receive a spurious timer interrupt. */ - vmi_timer_ops.set_alarm( - VMI_ALARM_WIRING | VMI_ALARM_IS_PERIODIC | VMI_CYCLES_AVAILABLE, - per_cpu(process_times_cycles_accounted_cpu, cpu) + cycles_per_alarm, - cycles_per_alarm); - /* Indicate this cpu is no longer nohz idle. */ - cpu_clear(cpu, nohz_cpu_mask); -} - -/* Called from interrupt handlers when (local) HZ timer is disabled. */ -void vmi_account_time_restart_hz_timer(void) -{ - unsigned long long cur_real_cycles, cur_process_times_cycles; - int cpu = smp_processor_id(); - - BUG_ON(!irqs_disabled()); - /* Account the time during which the HZ timer was disabled. */ - cur_real_cycles = read_real_cycles(); - cur_process_times_cycles = read_available_cycles(); - /* Update system wide (real) time state (xtime, jiffies). */ - vmi_account_real_cycles(cur_real_cycles); - /* Update per-cpu idle times. */ - vmi_account_no_hz_idle_cycles(cpu, cur_process_times_cycles); - /* Update time stolen from this cpu by the hypervisor. */ - vmi_account_stolen_cycles(cpu, cur_real_cycles, cur_process_times_cycles); - /* Reenable the hz timer. */ - vmi_reenable_hz_timer(cpu); -} - -#endif /* CONFIG_NO_IDLE_HZ */ - -/* UP (and no local-APIC) VMI-timer alarm interrupt handler. - * Handler for IRQ0. Not used when SMP or X86_LOCAL_APIC after - * APIC setup and setup_boot_vmi_alarm() is called. */ -static irqreturn_t vmi_timer_interrupt(int irq, void *dev_id) -{ - vmi_local_timer_interrupt(smp_processor_id()); - return IRQ_HANDLED; -} - -#ifdef CONFIG_X86_LOCAL_APIC - -/* SMP VMI-timer alarm interrupt handler. Handler for LVTT vector. - * Also used in UP when CONFIG_X86_LOCAL_APIC. - * The wrapper code is from arch/i386/kernel/apic.c#smp_apic_timer_interrupt. */ -void smp_apic_vmi_timer_interrupt(struct pt_regs *regs) -{ - struct pt_regs *old_regs = set_irq_regs(regs); - int cpu = smp_processor_id(); - - /* - * the NMI deadlock-detector uses this. - */ - per_cpu(irq_stat,cpu).apic_timer_irqs++; - - /* - * NOTE! We'd better ACK the irq immediately, - * because timer handling can be slow. - */ - ack_APIC_irq(); - - /* - * update_process_times() expects us to have done irq_enter(). - * Besides, if we don't timer interrupts ignore the global - * interrupt lock, which is the WrongThing (tm) to do. - */ - irq_enter(); - vmi_local_timer_interrupt(cpu); - irq_exit(); - set_irq_regs(old_regs); -} - -#endif /* CONFIG_X86_LOCAL_APIC */ |