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[PATCH] clockevents: i386 drivers

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Add clockevent drivers for i386: lapic (local) and PIT/HPET (global).  Update
the timer IRQ to call into the PIT/HPET driver's event handler and the
lapic-timer IRQ to call into the lapic clockevent driver.  The assignement of
timer functionality is delegated to the core framework code and replaces the
compile and runtime evalution in do_timer_interrupt_hook()

Use the clockevents broadcast support and implement the lapic_broadcast
function for ACPI.

No changes to existing functionality.

[ kdump fix from Vivek Goyal <vgoyal@in.ibm.com> ]
[ fixes based on review feedback from Arjan van de Ven <arjan@infradead.org> ]
Cleanups-from: Adrian Bunk <bunk@stusta.de>
Build-fixes-from: Andrew Morton <akpm@osdl.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: john stultz <johnstul@us.ibm.com>
Cc: Roman Zippel <zippel@linux-m68k.org>
Cc: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Thomas Gleixner 2007-02-16 01:28:04 -08:00 committed by Linus Torvalds
parent 79bf2bb335
commit e9e2cdb412
17 changed files with 812 additions and 848 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

8
arch/i386/Kconfig
View File

@ -22,6 +22,14 @@ config CLOCKSOURCE_WATCHDOG
bool
default y
config GENERIC_CLOCKEVENTS
bool
default y
config GENERIC_CLOCKEVENTS_BROADCAST
bool
default y
config LOCKDEP_SUPPORT
bool
default y

1
arch/i386/kernel/Makefile
View File

@ -32,7 +32,6 @@ obj-$(CONFIG_KPROBES) += kprobes.o
obj-$(CONFIG_MODULES) += module.o
obj-y += sysenter.o vsyscall.o
obj-$(CONFIG_ACPI_SRAT) += srat.o
obj-$(CONFIG_HPET_TIMER) += time_hpet.o
obj-$(CONFIG_EFI) += efi.o efi_stub.o
obj-$(CONFIG_DOUBLEFAULT) += doublefault.o
obj-$(CONFIG_VM86) += vm86.o

291
arch/i386/kernel/apic.c
View File

@ -25,6 +25,7 @@
#include <linux/kernel_stat.h>
#include <linux/sysdev.h>
#include <linux/cpu.h>
#include <linux/clockchips.h>
#include <linux/module.h>
#include <asm/atomic.h>
@ -51,12 +52,6 @@
# error SPURIOUS_APIC_VECTOR definition error
#endif
/*
* cpu_mask that denotes the CPUs that needs timer interrupt coming in as
* IPIs in place of local APIC timers
*/
static cpumask_t timer_bcast_ipi;
/*
* Knob to control our willingness to enable the local APIC.
*
@ -64,16 +59,38 @@ static cpumask_t timer_bcast_ipi;
*/
static int enable_local_apic __initdata = 0;
/* Enable local APIC timer for highres/dyntick on UP */
static int enable_local_apic_timer __initdata = 0;
/*
* Debug level, exported for io_apic.c
*/
int apic_verbosity;
static unsigned int calibration_result;
static int lapic_next_event(unsigned long delta,
struct clock_event_device *evt);
static void lapic_timer_setup(enum clock_event_mode mode,
struct clock_event_device *evt);
static void lapic_timer_broadcast(cpumask_t mask);
static void apic_pm_activate(void);
/* Using APIC to generate smp_local_timer_interrupt? */
int using_apic_timer __read_mostly = 0;
/*
* The local apic timer can be used for any function which is CPU local.
*/
static struct clock_event_device lapic_clockevent = {
.name = "lapic",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT
| CLOCK_EVT_FEAT_C3STOP,
.shift = 32,
.set_mode = lapic_timer_setup,
.set_next_event = lapic_next_event,
.broadcast = lapic_timer_broadcast,
.rating = 100,
.irq = -1,
};
static DEFINE_PER_CPU(struct clock_event_device, lapic_events);
/* Local APIC was disabled by the BIOS and enabled by the kernel */
static int enabled_via_apicbase;
@ -151,6 +168,11 @@ int lapic_get_maxlvt(void)
* closely follows bus clocks.
*/
/*
* FIXME: Move this to i8253.h. There is no need to keep the access to
* the PIT scattered all around the place -tglx
*/
/*
* The timer chip is already set up at HZ interrupts per second here,
* but we do not accept timer interrupts yet. We only allow the BP
@ -209,16 +231,17 @@ void (*wait_timer_tick)(void) __devinitdata = wait_8254_wraparound;
#define APIC_DIVISOR 16
static void __setup_APIC_LVTT(unsigned int clocks)
static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)
{
unsigned int lvtt_value, tmp_value;
int cpu = smp_processor_id();
lvtt_value = APIC_LVT_TIMER_PERIODIC | LOCAL_TIMER_VECTOR;
lvtt_value = LOCAL_TIMER_VECTOR;
if (!oneshot)
lvtt_value |= APIC_LVT_TIMER_PERIODIC;
if (!lapic_is_integrated())
lvtt_value |= SET_APIC_TIMER_BASE(APIC_TIMER_BASE_DIV);
if (cpu_isset(cpu, timer_bcast_ipi))
if (!irqen)
lvtt_value |= APIC_LVT_MASKED;
apic_write_around(APIC_LVTT, lvtt_value);
@ -231,31 +254,80 @@ static void __setup_APIC_LVTT(unsigned int clocks)
& ~(APIC_TDR_DIV_1 | APIC_TDR_DIV_TMBASE))
| APIC_TDR_DIV_16);
apic_write_around(APIC_TMICT, clocks/APIC_DIVISOR);
if (!oneshot)
apic_write_around(APIC_TMICT, clocks/APIC_DIVISOR);
}
static void __devinit setup_APIC_timer(unsigned int clocks)
/*
* Program the next event, relative to now
*/
static int lapic_next_event(unsigned long delta,
struct clock_event_device *evt)
{
apic_write_around(APIC_TMICT, delta);
return 0;
}
/*
* Setup the lapic timer in periodic or oneshot mode
*/
static void lapic_timer_setup(enum clock_event_mode mode,
struct clock_event_device *evt)
{
unsigned long flags;
unsigned int v;
local_irq_save(flags);
/*
* Wait for IRQ0's slice:
*/
wait_timer_tick();
__setup_APIC_LVTT(clocks);
switch (mode) {
case CLOCK_EVT_MODE_PERIODIC:
case CLOCK_EVT_MODE_ONESHOT:
__setup_APIC_LVTT(calibration_result,
mode != CLOCK_EVT_MODE_PERIODIC, 1);
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
v = apic_read(APIC_LVTT);
v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
apic_write_around(APIC_LVTT, v);
break;
}
local_irq_restore(flags);
}
/*
* Local APIC timer broadcast function
*/
static void lapic_timer_broadcast(cpumask_t mask)
{
#ifdef CONFIG_SMP
send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
#endif
}
/*
* Setup the local APIC timer for this CPU. Copy the initilized values
* of the boot CPU and register the clock event in the framework.
*/
static void __devinit setup_APIC_timer(void)
{
struct clock_event_device *levt = &__get_cpu_var(lapic_events);
memcpy(levt, &lapic_clockevent, sizeof(*levt));
levt->cpumask = cpumask_of_cpu(smp_processor_id());
clockevents_register_device(levt);
}
/*
* In this function we calibrate APIC bus clocks to the external
* timer. Unfortunately we cannot use jiffies and the timer irq
* to calibrate, since some later bootup code depends on getting
* the first irq? Ugh.
*
* TODO: Fix this rather than saying "Ugh" -tglx
*
* We want to do the calibration only once since we
* want to have local timer irqs syncron. CPUs connected
* by the same APIC bus have the very same bus frequency.
@ -278,7 +350,7 @@ static int __init calibrate_APIC_clock(void)
* value into the APIC clock, we just want to get the
* counter running for calibration.
*/
__setup_APIC_LVTT(1000000000);
__setup_APIC_LVTT(1000000000, 0, 0);
/*
* The timer chip counts down to zero. Let's wait
@ -315,6 +387,17 @@ static int __init calibrate_APIC_clock(void)
result = (tt1-tt2)*APIC_DIVISOR/LOOPS;
/* Calculate the scaled math multiplication factor */
lapic_clockevent.mult = div_sc(tt1-tt2, TICK_NSEC * LOOPS, 32);
lapic_clockevent.max_delta_ns =
clockevent_delta2ns(0x7FFFFF, &lapic_clockevent);
lapic_clockevent.min_delta_ns =
clockevent_delta2ns(0xF, &lapic_clockevent);
apic_printk(APIC_VERBOSE, "..... tt1-tt2 %ld\n", tt1 - tt2);
apic_printk(APIC_VERBOSE, "..... mult: %ld\n", lapic_clockevent.mult);
apic_printk(APIC_VERBOSE, "..... calibration result: %ld\n", result);
if (cpu_has_tsc)
apic_printk(APIC_VERBOSE, "..... CPU clock speed is "
"%ld.%04ld MHz.\n",
@ -329,13 +412,10 @@ static int __init calibrate_APIC_clock(void)
return result;
}
static unsigned int calibration_result;
void __init setup_boot_APIC_clock(void)
{
unsigned long flags;
apic_printk(APIC_VERBOSE, "Using local APIC timer interrupts.\n");
using_apic_timer = 1;
local_irq_save(flags);
@ -343,97 +423,47 @@ void __init setup_boot_APIC_clock(void)
/*
* Now set up the timer for real.
*/
setup_APIC_timer(calibration_result);
setup_APIC_timer();
local_irq_restore(flags);
}
void __devinit setup_secondary_APIC_clock(void)
{
setup_APIC_timer(calibration_result);
setup_APIC_timer();
}
void disable_APIC_timer(void)
{
if (using_apic_timer) {
unsigned long v;
v = apic_read(APIC_LVTT);
/*
* When an illegal vector value (0-15) is written to an LVT
* entry and delivery mode is Fixed, the APIC may signal an
* illegal vector error, with out regard to whether the mask
* bit is set or whether an interrupt is actually seen on
* input.
*
* Boot sequence might call this function when the LVTT has
* '0' vector value. So make sure vector field is set to
* valid value.
*/
v |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
apic_write_around(APIC_LVTT, v);
}
}
void enable_APIC_timer(void)
{
int cpu = smp_processor_id();
if (using_apic_timer && !cpu_isset(cpu, timer_bcast_ipi)) {
unsigned long v;
v = apic_read(APIC_LVTT);
apic_write_around(APIC_LVTT, v & ~APIC_LVT_MASKED);
}
}
void switch_APIC_timer_to_ipi(void *cpumask)
{
cpumask_t mask = *(cpumask_t *)cpumask;
int cpu = smp_processor_id();
if (cpu_isset(cpu, mask) &&
!cpu_isset(cpu, timer_bcast_ipi)) {
disable_APIC_timer();
cpu_set(cpu, timer_bcast_ipi);
}
}
EXPORT_SYMBOL(switch_APIC_timer_to_ipi);
void switch_ipi_to_APIC_timer(void *cpumask)
{
cpumask_t mask = *(cpumask_t *)cpumask;
int cpu = smp_processor_id();
if (cpu_isset(cpu, mask) &&
cpu_isset(cpu, timer_bcast_ipi)) {
cpu_clear(cpu, timer_bcast_ipi);
enable_APIC_timer();
}
}
EXPORT_SYMBOL(switch_ipi_to_APIC_timer);
/*
* Local timer interrupt handler. It does both profiling and
* process statistics/rescheduling.
* The guts of the apic timer interrupt
*/
inline void smp_local_timer_interrupt(void)
static void local_apic_timer_interrupt(void)
{
profile_tick(CPU_PROFILING);
#ifdef CONFIG_SMP
update_process_times(user_mode_vm(get_irq_regs()));
#endif
int cpu = smp_processor_id();
struct clock_event_device *evt = &per_cpu(lapic_events, cpu);
/*
* We take the 'long' return path, and there every subsystem
* grabs the apropriate locks (kernel lock/ irq lock).
* Normally we should not be here till LAPIC has been
* initialized but in some cases like kdump, its possible that
* there is a pending LAPIC timer interrupt from previous
* kernel's context and is delivered in new kernel the moment
* interrupts are enabled.
*
* we might want to decouple profiling from the 'long path',
* and do the profiling totally in assembly.
*
* Currently this isn't too much of an issue (performance wise),
* we can take more than 100K local irqs per second on a 100 MHz P5.
* Interrupts are enabled early and LAPIC is setup much later,
* hence its possible that when we get here evt->event_handler
* is NULL. Check for event_handler being NULL and discard
* the interrupt as spurious.
*/
if (!evt->event_handler) {
printk(KERN_WARNING
"Spurious LAPIC timer interrupt on cpu %d\n", cpu);
/* Switch it off */
lapic_timer_setup(CLOCK_EVT_MODE_SHUTDOWN, evt);
return;
}
per_cpu(irq_stat, cpu).apic_timer_irqs++;
evt->event_handler(evt);
}
/*
@ -445,15 +475,9 @@ inline void smp_local_timer_interrupt(void)
* interrupt as well. Thus we cannot inline the local irq ... ]
*/
fastcall void smp_apic_timer_interrupt(struct pt_regs *regs)
void fastcall smp_apic_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,
@ -467,43 +491,12 @@ fastcall void smp_apic_timer_interrupt(struct pt_regs *regs)
*/
exit_idle();
irq_enter();
smp_local_timer_interrupt();
local_apic_timer_interrupt();
irq_exit();
set_irq_regs(old_regs);
}
#ifndef CONFIG_SMP
static void up_apic_timer_interrupt_call(void)
{
int cpu = smp_processor_id();
/*
* the NMI deadlock-detector uses this.
*/
per_cpu(irq_stat, cpu).apic_timer_irqs++;
smp_local_timer_interrupt();
}
#endif
void smp_send_timer_broadcast_ipi(void)
{
cpumask_t mask;
cpus_and(mask, cpu_online_map, timer_bcast_ipi);
if (!cpus_empty(mask)) {
#ifdef CONFIG_SMP
send_IPI_mask(mask, LOCAL_TIMER_VECTOR);
#else
/*
* We can directly call the apic timer interrupt handler
* in UP case. Minus all irq related functions
*/
up_apic_timer_interrupt_call();
#endif
}
}
int setup_profiling_timer(unsigned int multiplier)
{
return -EINVAL;
@ -914,6 +907,11 @@ void __devinit setup_local_APIC(void)
printk(KERN_INFO "No ESR for 82489DX.\n");
}
/* Disable the local apic timer */
value = apic_read(APIC_LVTT);
value |= (APIC_LVT_MASKED | LOCAL_TIMER_VECTOR);
apic_write_around(APIC_LVTT, value);
setup_apic_nmi_watchdog(NULL);
apic_pm_activate();
}
@ -1128,6 +1126,13 @@ static int __init parse_nolapic(char *arg)
}
early_param("nolapic", parse_nolapic);
static int __init apic_enable_lapic_timer(char *str)
{
enable_local_apic_timer = 1;
return 0;
}
early_param("lapictimer", apic_enable_lapic_timer);
static int __init apic_set_verbosity(char *str)
{
if (strcmp("debug", str) == 0)
@ -1147,7 +1152,7 @@ __setup("apic=", apic_set_verbosity);
/*
* This interrupt should _never_ happen with our APIC/SMP architecture
*/
fastcall void smp_spurious_interrupt(struct pt_regs *regs)
void smp_spurious_interrupt(struct pt_regs *regs)
{
unsigned long v;
@ -1171,7 +1176,7 @@ fastcall void smp_spurious_interrupt(struct pt_regs *regs)
/*
* This interrupt should never happen with our APIC/SMP architecture
*/
fastcall void smp_error_interrupt(struct pt_regs *regs)
void smp_error_interrupt(struct pt_regs *regs)
{
unsigned long v, v1;

496
arch/i386/kernel/hpet.c
View File

@ -1,4 +1,5 @@
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/errno.h>
#include <linux/hpet.h>
#include <linux/init.h>
@ -6,17 +7,278 @@
#include <asm/hpet.h>
#include <asm/io.h>
extern struct clock_event_device *global_clock_event;
#define HPET_MASK CLOCKSOURCE_MASK(32)
#define HPET_SHIFT 22
/* FSEC = 10^-15 NSEC = 10^-9 */
#define FSEC_PER_NSEC 1000000
static void __iomem *hpet_ptr;
/*
* HPET address is set in acpi/boot.c, when an ACPI entry exists
*/
unsigned long hpet_address;
static void __iomem * hpet_virt_address;
static inline unsigned long hpet_readl(unsigned long a)
{
return readl(hpet_virt_address + a);
}
static inline void hpet_writel(unsigned long d, unsigned long a)
{
writel(d, hpet_virt_address + a);
}
/*
* HPET command line enable / disable
*/
static int boot_hpet_disable;
static int __init hpet_setup(char* str)
{
if (str) {
if (!strncmp("disable", str, 7))
boot_hpet_disable = 1;
}
return 1;
}
__setup("hpet=", hpet_setup);
static inline int is_hpet_capable(void)
{
return (!boot_hpet_disable && hpet_address);
}
/*
* HPET timer interrupt enable / disable
*/
static int hpet_legacy_int_enabled;
/**
* is_hpet_enabled - check whether the hpet timer interrupt is enabled
*/
int is_hpet_enabled(void)
{
return is_hpet_capable() && hpet_legacy_int_enabled;
}
/*
* When the hpet driver (/dev/hpet) is enabled, we need to reserve
* timer 0 and timer 1 in case of RTC emulation.
*/
#ifdef CONFIG_HPET
static void hpet_reserve_platform_timers(unsigned long id)
{
struct hpet __iomem *hpet = hpet_virt_address;
struct hpet_timer __iomem *timer = &hpet->hpet_timers[2];
unsigned int nrtimers, i;
struct hpet_data hd;
nrtimers = ((id & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT) + 1;
memset(&hd, 0, sizeof (hd));
hd.hd_phys_address = hpet_address;
hd.hd_address = hpet_virt_address;
hd.hd_nirqs = nrtimers;
hd.hd_flags = HPET_DATA_PLATFORM;
hpet_reserve_timer(&hd, 0);
#ifdef CONFIG_HPET_EMULATE_RTC
hpet_reserve_timer(&hd, 1);
#endif
hd.hd_irq[0] = HPET_LEGACY_8254;
hd.hd_irq[1] = HPET_LEGACY_RTC;
for (i = 2; i < nrtimers; timer++, i++)
hd.hd_irq[i] = (timer->hpet_config & Tn_INT_ROUTE_CNF_MASK) >>
Tn_INT_ROUTE_CNF_SHIFT;
hpet_alloc(&hd);
}
#else
static void hpet_reserve_platform_timers(unsigned long id) { }
#endif
/*
* Common hpet info
*/
static unsigned long hpet_period;
static void hpet_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt);
static int hpet_next_event(unsigned long delta,
struct clock_event_device *evt);
/*
* The hpet clock event device
*/
static struct clock_event_device hpet_clockevent = {
.name = "hpet",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = hpet_set_mode,
.set_next_event = hpet_next_event,
.shift = 32,
.irq = 0,
};
static void hpet_start_counter(void)
{
unsigned long cfg = hpet_readl(HPET_CFG);
cfg &= ~HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
hpet_writel(0, HPET_COUNTER);
hpet_writel(0, HPET_COUNTER + 4);
cfg |= HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
}
static void hpet_enable_int(void)
{
unsigned long cfg = hpet_readl(HPET_CFG);
cfg |= HPET_CFG_LEGACY;
hpet_writel(cfg, HPET_CFG);
hpet_legacy_int_enabled = 1;
}
static void hpet_set_mode(enum clock_event_mode mode,
struct clock_event_device *evt)
{
unsigned long cfg, cmp, now;
uint64_t delta;
switch(mode) {
case CLOCK_EVT_MODE_PERIODIC:
delta = ((uint64_t)(NSEC_PER_SEC/HZ)) * hpet_clockevent.mult;
delta >>= hpet_clockevent.shift;
now = hpet_readl(HPET_COUNTER);
cmp = now + (unsigned long) delta;
cfg = hpet_readl(HPET_T0_CFG);
cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
HPET_TN_SETVAL | HPET_TN_32BIT;
hpet_writel(cfg, HPET_T0_CFG);
/*
* The first write after writing TN_SETVAL to the
* config register sets the counter value, the second
* write sets the period.
*/
hpet_writel(cmp, HPET_T0_CMP);
udelay(1);
hpet_writel((unsigned long) delta, HPET_T0_CMP);
break;
case CLOCK_EVT_MODE_ONESHOT:
cfg = hpet_readl(HPET_T0_CFG);
cfg &= ~HPET_TN_PERIODIC;
cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
hpet_writel(cfg, HPET_T0_CFG);
break;
case CLOCK_EVT_MODE_UNUSED:
case CLOCK_EVT_MODE_SHUTDOWN:
cfg = hpet_readl(HPET_T0_CFG);
cfg &= ~HPET_TN_ENABLE;
hpet_writel(cfg, HPET_T0_CFG);
break;
}
}
static int hpet_next_event(unsigned long delta,
struct clock_event_device *evt)
{
unsigned long cnt;
cnt = hpet_readl(HPET_COUNTER);
cnt += delta;
hpet_writel(cnt, HPET_T0_CMP);
return ((long)(hpet_readl(HPET_COUNTER) - cnt ) > 0);
}
/*
* Try to setup the HPET timer
*/
int __init hpet_enable(void)
{
unsigned long id;
uint64_t hpet_freq;
if (!is_hpet_capable())
return 0;
hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
/*
* Read the period and check for a sane value:
*/
hpet_period = hpet_readl(HPET_PERIOD);
if (hpet_period < HPET_MIN_PERIOD || hpet_period > HPET_MAX_PERIOD)
goto out_nohpet;
/*
* The period is a femto seconds value. We need to calculate the
* scaled math multiplication factor for nanosecond to hpet tick
* conversion.
*/
hpet_freq = 1000000000000000ULL;
do_div(hpet_freq, hpet_period);
hpet_clockevent.mult = div_sc((unsigned long) hpet_freq,
NSEC_PER_SEC, 32);
/* Calculate the min / max delta */
hpet_clockevent.max_delta_ns = clockevent_delta2ns(0x7FFFFFFF,
&hpet_clockevent);
hpet_clockevent.min_delta_ns = clockevent_delta2ns(0x30,
&hpet_clockevent);
/*
* Read the HPET ID register to retrieve the IRQ routing
* information and the number of channels
*/
id = hpet_readl(HPET_ID);
#ifdef CONFIG_HPET_EMULATE_RTC
/*
* The legacy routing mode needs at least two channels, tick timer
* and the rtc emulation channel.
*/
if (!(id & HPET_ID_NUMBER))
goto out_nohpet;
#endif
/* Start the counter */
hpet_start_counter();
if (id & HPET_ID_LEGSUP) {
hpet_enable_int();
hpet_reserve_platform_timers(id);
/*
* Start hpet with the boot cpu mask and make it
* global after the IO_APIC has been initialized.
*/
hpet_clockevent.cpumask =cpumask_of_cpu(0);
clockevents_register_device(&hpet_clockevent);
global_clock_event = &hpet_clockevent;
return 1;
}
return 0;
out_nohpet:
iounmap(hpet_virt_address);
hpet_virt_address = NULL;
return 0;
}
/*
* Clock source related code
*/
static cycle_t read_hpet(void)
{
return (cycle_t)readl(hpet_ptr);
return (cycle_t)hpet_readl(HPET_COUNTER);
}
static struct clocksource clocksource_hpet = {
@ -24,28 +286,17 @@ static struct clocksource clocksource_hpet = {
.rating = 250,
.read = read_hpet,
.mask = HPET_MASK,
.mult = 0, /* set below */
.shift = HPET_SHIFT,
.flags = CLOCK_SOURCE_IS_CONTINUOUS,
};
static int __init init_hpet_clocksource(void)
{
unsigned long hpet_period;
void __iomem* hpet_base;
u64 tmp;
int err;
if (!is_hpet_enabled())
if (!hpet_virt_address)
return -ENODEV;
/* calculate the hpet address: */
hpet_base = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
hpet_ptr = hpet_base + HPET_COUNTER;
/* calculate the frequency: */
hpet_period = readl(hpet_base + HPET_PERIOD);
/*
* hpet period is in femto seconds per cycle
* so we need to convert this to ns/cyc units
@ -61,11 +312,218 @@ static int __init init_hpet_clocksource(void)
do_div(tmp, FSEC_PER_NSEC);
clocksource_hpet.mult = (u32)tmp;
err = clocksource_register(&clocksource_hpet);
if (err)
iounmap(hpet_base);
return err;
return clocksource_register(&clocksource_hpet);
}
module_init(init_hpet_clocksource);
#ifdef CONFIG_HPET_EMULATE_RTC
/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET
* is enabled, we support RTC interrupt functionality in software.
* RTC has 3 kinds of interrupts:
* 1) Update Interrupt - generate an interrupt, every sec, when RTC clock
* is updated
* 2) Alarm Interrupt - generate an interrupt at a specific time of day
* 3) Periodic Interrupt - generate periodic interrupt, with frequencies
* 2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2)
* (1) and (2) above are implemented using polling at a frequency of
* 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt
* overhead. (DEFAULT_RTC_INT_FREQ)
* For (3), we use interrupts at 64Hz or user specified periodic
* frequency, whichever is higher.
*/
#include <linux/mc146818rtc.h>
#include <linux/rtc.h>
#define DEFAULT_RTC_INT_FREQ 64
#define DEFAULT_RTC_SHIFT 6
#define RTC_NUM_INTS 1
static unsigned long hpet_rtc_flags;
static unsigned long hpet_prev_update_sec;
static struct rtc_time hpet_alarm_time;
static unsigned long hpet_pie_count;
static unsigned long hpet_t1_cmp;
static unsigned long hpet_default_delta;
static unsigned long hpet_pie_delta;
static unsigned long hpet_pie_limit;
/*
* Timer 1 for RTC emulation. We use one shot mode, as periodic mode
* is not supported by all HPET implementations for timer 1.
*
* hpet_rtc_timer_init() is called when the rtc is initialized.
*/
int hpet_rtc_timer_init(void)
{
unsigned long cfg, cnt, delta, flags;
if (!is_hpet_enabled())
return 0;
if (!hpet_default_delta) {
uint64_t clc;
clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
clc >>= hpet_clockevent.shift + DEFAULT_RTC_SHIFT;
hpet_default_delta = (unsigned long) clc;
}
if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
delta = hpet_default_delta;
else
delta = hpet_pie_delta;
local_irq_save(flags);
cnt = delta + hpet_readl(HPET_COUNTER);
hpet_writel(cnt, HPET_T1_CMP);
hpet_t1_cmp = cnt;
cfg = hpet_readl(HPET_T1_CFG);
cfg &= ~HPET_TN_PERIODIC;
cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
hpet_writel(cfg, HPET_T1_CFG);
local_irq_restore(flags);
return 1;
}
/*
* The functions below are called from rtc driver.
* Return 0 if HPET is not being used.
* Otherwise do the necessary changes and return 1.
*/
int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
{
if (!is_hpet_enabled())
return 0;
hpet_rtc_flags &= ~bit_mask;
return 1;
}
int hpet_set_rtc_irq_bit(unsigned long bit_mask)
{
unsigned long oldbits = hpet_rtc_flags;
if (!is_hpet_enabled())
return 0;
hpet_rtc_flags |= bit_mask;
if (!oldbits)
hpet_rtc_timer_init();
return 1;
}
int hpet_set_alarm_time(unsigned char hrs, unsigned char min,
unsigned char sec)
{
if (!is_hpet_enabled())
return 0;
hpet_alarm_time.tm_hour = hrs;
hpet_alarm_time.tm_min = min;
hpet_alarm_time.tm_sec = sec;
return 1;
}
int hpet_set_periodic_freq(unsigned long freq)
{
uint64_t clc;
if (!is_hpet_enabled())
return 0;
if (freq <= DEFAULT_RTC_INT_FREQ)
hpet_pie_limit = DEFAULT_RTC_INT_FREQ / freq;
else {
clc = (uint64_t) hpet_clockevent.mult * NSEC_PER_SEC;
do_div(clc, freq);
clc >>= hpet_clockevent.shift;
hpet_pie_delta = (unsigned long) clc;
}
return 1;
}
int hpet_rtc_dropped_irq(void)
{
return is_hpet_enabled();
}
static void hpet_rtc_timer_reinit(void)
{
unsigned long cfg, delta;
int lost_ints = -1;
if (unlikely(!hpet_rtc_flags)) {
cfg = hpet_readl(HPET_T1_CFG);
cfg &= ~HPET_TN_ENABLE;
hpet_writel(cfg, HPET_T1_CFG);
return;
}
if (!(hpet_rtc_flags & RTC_PIE) || hpet_pie_limit)
delta = hpet_default_delta;
else
delta = hpet_pie_delta;
/*
* Increment the comparator value until we are ahead of the
* current count.
*/
do {
hpet_t1_cmp += delta;
hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
lost_ints++;
} while ((long)(hpet_readl(HPET_COUNTER) - hpet_t1_cmp) > 0);
if (lost_ints) {
if (hpet_rtc_flags & RTC_PIE)
hpet_pie_count += lost_ints;
if (printk_ratelimit())
printk(KERN_WARNING "rtc: lost %d interrupts\n",
lost_ints);
}
}
irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
{
struct rtc_time curr_time;
unsigned long rtc_int_flag = 0;
hpet_rtc_timer_reinit();
if (hpet_rtc_flags & (RTC_UIE | RTC_AIE))
rtc_get_rtc_time(&curr_time);
if (hpet_rtc_flags & RTC_UIE &&
curr_time.tm_sec != hpet_prev_update_sec) {
rtc_int_flag = RTC_UF;
hpet_prev_update_sec = curr_time.tm_sec;
}
if (hpet_rtc_flags & RTC_PIE &&
++hpet_pie_count >= hpet_pie_limit) {
rtc_int_flag |= RTC_PF;
hpet_pie_count = 0;
}
if (hpet_rtc_flags & RTC_PIE &&
(curr_time.tm_sec == hpet_alarm_time.tm_sec) &&
(curr_time.tm_min == hpet_alarm_time.tm_min) &&
(curr_time.tm_hour == hpet_alarm_time.tm_hour))
rtc_int_flag |= RTC_AF;
if (rtc_int_flag) {
rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
rtc_interrupt(rtc_int_flag, dev_id);
}
return IRQ_HANDLED;
}
#endif

96
arch/i386/kernel/i8253.c
View File

@ -2,7 +2,7 @@
* i8253.c 8253/PIT functions
*
*/
#include <linux/clocksource.h>
#include <linux/clockchips.h>
#include <linux/spinlock.h>
#include <linux/jiffies.h>
#include <linux/sysdev.h>
@ -19,19 +19,99 @@
DEFINE_SPINLOCK(i8253_lock);
EXPORT_SYMBOL(i8253_lock);
void setup_pit_timer(void)
/*
* HPET replaces the PIT, when enabled. So we need to know, which of
* the two timers is used
*/
struct clock_event_device *global_clock_event;
/*
* Initialize the PIT timer.
*
* This is also called after resume to bring the PIT into operation again.
*/
static void init_pit_timer(enum clock_event_mode mode,
struct clock_event_device *evt)
{
unsigned long flags;
spin_lock_irqsave(&i8253_lock, flags);
outb_p(0x34,PIT_MODE); /* binary, mode 2, LSB/MSB, ch 0 */
udelay(10);
outb_p(LATCH & 0xff , PIT_CH0); /* LSB */
udelay(10);
outb(LATCH >> 8 , PIT_CH0); /* MSB */
switch(mode) {
case CLOCK_EVT_MODE_PERIODIC:
/* binary, mode 2, LSB/MSB, ch 0 */
outb_p(0x34, PIT_MODE);
udelay(10);
outb_p(LATCH & 0xff , PIT_CH0); /* LSB */
udelay(10);
outb(LATCH >> 8 , PIT_CH0); /* MSB */
break;
case CLOCK_EVT_MODE_ONESHOT:
case CLOCK_EVT_MODE_SHUTDOWN:
case CLOCK_EVT_MODE_UNUSED:
/* One shot setup */
outb_p(0x38, PIT_MODE);
udelay(10);
break;
}
spin_unlock_irqrestore(&i8253_lock, flags);
}
/*
* Program the next event in oneshot mode
*
* Delta is given in PIT ticks
*/
static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
{
unsigned long flags;
spin_lock_irqsave(&i8253_lock, flags);
outb_p(delta & 0xff , PIT_CH0); /* LSB */
outb(delta >> 8 , PIT_CH0); /* MSB */
spin_unlock_irqrestore(&i8253_lock, flags);
return 0;
}
/*
* On UP the PIT can serve all of the possible timer functions. On SMP systems
* it can be solely used for the global tick.
*
* The profiling and update capabilites are switched off once the local apic is
* registered. This mechanism replaces the previous #ifdef LOCAL_APIC -
* !using_apic_timer decisions in do_timer_interrupt_hook()
*/
struct clock_event_device pit_clockevent = {
.name = "pit",
.features = CLOCK_EVT_FEAT_PERIODIC | CLOCK_EVT_FEAT_ONESHOT,
.set_mode = init_pit_timer,
.set_next_event = pit_next_event,
.shift = 32,
.irq = 0,
};
/*
* Initialize the conversion factor and the min/max deltas of the clock event
* structure and register the clock event source with the framework.
*/
void __init setup_pit_timer(void)
{
/*
* Start pit with the boot cpu mask and make it global after the
* IO_APIC has been initialized.
*/
pit_clockevent.cpumask = cpumask_of_cpu(0);
pit_clockevent.mult = div_sc(CLOCK_TICK_RATE, NSEC_PER_SEC, 32);
pit_clockevent.max_delta_ns =
clockevent_delta2ns(0x7FFF, &pit_clockevent);
pit_clockevent.min_delta_ns =
clockevent_delta2ns(0xF, &pit_clockevent);
clockevents_register_device(&pit_clockevent);
global_clock_event = &pit_clockevent;
}
/*
* Since the PIT overflows every tick, its not very useful
* to just read by itself. So use jiffies to emulate a free
@ -46,7 +126,7 @@ static cycle_t pit_read(void)
static u32 old_jifs;
spin_lock_irqsave(&i8253_lock, flags);
/*
/*
* Although our caller may have the read side of xtime_lock,
* this is now a seqlock, and we are cheating in this routine
* by having side effects on state that we cannot undo if

6
arch/i386/kernel/i8259.c
View File

@ -409,12 +409,6 @@ void __init native_init_IRQ(void)
*/
intr_init_hook();
/*
* Set the clock to HZ Hz, we already have a valid
* vector now:
*/
setup_pit_timer();
/*
* External FPU? Set up irq13 if so, for
* original braindamaged IBM FERR coupling.

5
arch/i386/kernel/smpboot.c
View File

@ -287,9 +287,7 @@ static void __cpuinit smp_callin(void)
/*
* Save our processor parameters
*/
smp_store_cpu_info(cpuid);
disable_APIC_timer();
smp_store_cpu_info(cpuid);
/*
* Allow the master to continue.
@ -408,7 +406,6 @@ static void __cpuinit start_secondary(void *unused)
enable_NMI_through_LVT0(NULL);
enable_8259A_irq(0);
}
enable_APIC_timer();
/*
* low-memory mappings have been cleared, flush them from
* the local TLBs too.

70
arch/i386/kernel/time.c
View File

@ -159,15 +159,6 @@ EXPORT_SYMBOL(profile_pc);
*/
irqreturn_t timer_interrupt(int irq, void *dev_id)
{
/*
* Here we are in the timer irq handler. We just have irqs locally
* disabled but we don't know if the timer_bh is running on the other
* CPU. We need to avoid to SMP race with it. NOTE: we don' t need
* the irq version of write_lock because as just said we have irq
* locally disabled. -arca
*/
write_seqlock(&xtime_lock);
#ifdef CONFIG_X86_IO_APIC
if (timer_ack) {
/*
@ -186,7 +177,6 @@ irqreturn_t timer_interrupt(int irq, void *dev_id)
do_timer_interrupt_hook();
if (MCA_bus) {
/* The PS/2 uses level-triggered interrupts. You can't
turn them off, nor would you want to (any attempt to
@ -201,13 +191,6 @@ irqreturn_t timer_interrupt(int irq, void *dev_id)
outb_p( irq_v|0x80, 0x61 ); /* reset the IRQ */
}
write_sequnlock(&xtime_lock);
#ifdef CONFIG_X86_LOCAL_APIC
if (using_apic_timer)
smp_send_timer_broadcast_ipi();
#endif
return IRQ_HANDLED;
}
@ -277,63 +260,16 @@ void notify_arch_cmos_timer(void)
mod_timer(&sync_cmos_timer, jiffies + 1);
}
static int timer_resume(struct sys_device *dev)
{
#ifdef CONFIG_HPET_TIMER
if (is_hpet_enabled())
hpet_reenable();
#endif
setup_pit_timer();
touch_softlockup_watchdog();
return 0;
}
static struct sysdev_class timer_sysclass = {
.resume = timer_resume,
set_kset_name("timer"),
};
/* XXX this driverfs stuff should probably go elsewhere later -john */
static struct sys_device device_timer = {
.id = 0,
.cls = &timer_sysclass,
};
static int time_init_device(void)
{
int error = sysdev_class_register(&timer_sysclass);
if (!error)
error = sysdev_register(&device_timer);
return error;
}
device_initcall(time_init_device);
#ifdef CONFIG_HPET_TIMER
extern void (*late_time_init)(void);
/* Duplicate of time_init() below, with hpet_enable part added */
static void __init hpet_time_init(void)
{
if ((hpet_enable() >= 0) && hpet_use_timer) {
printk("Using HPET for base-timer\n");
}
if (!hpet_enable())
setup_pit_timer();
do_time_init();
}
#endif
void __init time_init(void)
{
#ifdef CONFIG_HPET_TIMER
if (is_hpet_capable()) {
/*
* HPET initialization needs to do memory-mapped io. So, let
* us do a late initialization after mem_init().
*/
late_time_init = hpet_time_init;
return;
}
#endif
do_time_init();
late_time_init = hpet_time_init;
}

497
arch/i386/kernel/time_hpet.c
View File

@ -1,497 +0,0 @@
/*
* linux/arch/i386/kernel/time_hpet.c
* This code largely copied from arch/x86_64/kernel/time.c
* See that file for credits.
*
* 2003-06-30 Venkatesh Pallipadi - Additional changes for HPET support
*/
#include <linux/errno.h>
#include <linux/kernel.h>
#include <linux/param.h>
#include <linux/string.h>
#include <linux/init.h>
#include <linux/smp.h>
#include <asm/timer.h>
#include <asm/fixmap.h>
#include <asm/apic.h>
#include <linux/timex.h>
#include <asm/hpet.h>
#include <linux/hpet.h>
static unsigned long hpet_period; /* fsecs / HPET clock */
unsigned long hpet_tick; /* hpet clks count per tick */
unsigned long hpet_address; /* hpet memory map physical address */
int hpet_use_timer;
static int use_hpet; /* can be used for runtime check of hpet */
static int boot_hpet_disable; /* boottime override for HPET timer */
static void __iomem * hpet_virt_address; /* hpet kernel virtual address */
#define FSEC_TO_USEC (1000000000UL)
int hpet_readl(unsigned long a)
{
return readl(hpet_virt_address + a);
}
static void hpet_writel(unsigned long d, unsigned long a)
{
writel(d, hpet_virt_address + a);
}
#ifdef CONFIG_X86_LOCAL_APIC
/*
* HPET counters dont wrap around on every tick. They just change the
* comparator value and continue. Next tick can be caught by checking
* for a change in the comparator value. Used in apic.c.
*/
static void __devinit wait_hpet_tick(void)
{
unsigned int start_cmp_val, end_cmp_val;
start_cmp_val = hpet_readl(HPET_T0_CMP);
do {
end_cmp_val = hpet_readl(HPET_T0_CMP);
} while (start_cmp_val == end_cmp_val);
}
#endif
static int hpet_timer_stop_set_go(unsigned long tick)
{
unsigned int cfg;
/*
* Stop the timers and reset the main counter.
*/
cfg = hpet_readl(HPET_CFG);
cfg &= ~HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
hpet_writel(0, HPET_COUNTER);
hpet_writel(0, HPET_COUNTER + 4);
if (hpet_use_timer) {
/*
* Set up timer 0, as periodic with first interrupt to happen at
* hpet_tick, and period also hpet_tick.
*/
cfg = hpet_readl(HPET_T0_CFG);
cfg |= HPET_TN_ENABLE | HPET_TN_PERIODIC |
HPET_TN_SETVAL | HPET_TN_32BIT;
hpet_writel(cfg, HPET_T0_CFG);
/*
* The first write after writing TN_SETVAL to the config register sets
* the counter value, the second write sets the threshold.
*/
hpet_writel(tick, HPET_T0_CMP);
hpet_writel(tick, HPET_T0_CMP);
}
/*
* Go!
*/
cfg = hpet_readl(HPET_CFG);
if (hpet_use_timer)
cfg |= HPET_CFG_LEGACY;
cfg |= HPET_CFG_ENABLE;
hpet_writel(cfg, HPET_CFG);
return 0;
}
/*
* Check whether HPET was found by ACPI boot parse. If yes setup HPET
* counter 0 for kernel base timer.
*/
int __init hpet_enable(void)
{
unsigned int id;
unsigned long tick_fsec_low, tick_fsec_high; /* tick in femto sec */
unsigned long hpet_tick_rem;
if (boot_hpet_disable)
return -1;
if (!hpet_address) {
return -1;
}
hpet_virt_address = ioremap_nocache(hpet_address, HPET_MMAP_SIZE);
/*
* Read the period, compute tick and quotient.
*/
id = hpet_readl(HPET_ID);
/*
* We are checking for value '1' or more in number field if
* CONFIG_HPET_EMULATE_RTC is set because we will need an
* additional timer for RTC emulation.
* However, we can do with one timer otherwise using the
* the single HPET timer for system time.
*/
#ifdef CONFIG_HPET_EMULATE_RTC
if (!(id & HPET_ID_NUMBER)) {
iounmap(hpet_virt_address);
hpet_virt_address = NULL;
return -1;
}
#endif
hpet_period = hpet_readl(HPET_PERIOD);
if ((hpet_period < HPET_MIN_PERIOD) || (hpet_period > HPET_MAX_PERIOD)) {
iounmap(hpet_virt_address);
hpet_virt_address = NULL;
return -1;
}
/*
* 64 bit math
* First changing tick into fsec
* Then 64 bit div to find number of hpet clk per tick
*/
ASM_MUL64_REG(tick_fsec_low, tick_fsec_high,
KERNEL_TICK_USEC, FSEC_TO_USEC);
ASM_DIV64_REG(hpet_tick, hpet_tick_rem,
hpet_period, tick_fsec_low, tick_fsec_high);
if (hpet_tick_rem > (hpet_period >> 1))
hpet_tick++; /* rounding the result */
hpet_use_timer = id & HPET_ID_LEGSUP;
if (hpet_timer_stop_set_go(hpet_tick)) {
iounmap(hpet_virt_address);
hpet_virt_address = NULL;
return -1;
}
use_hpet = 1;
#ifdef CONFIG_HPET
{
struct hpet_data hd;
unsigned int ntimer;
memset(&hd, 0, sizeof (hd));
ntimer = hpet_readl(HPET_ID);
ntimer = (ntimer & HPET_ID_NUMBER) >> HPET_ID_NUMBER_SHIFT;
ntimer++;
/*
* Register with driver.
* Timer0 and Timer1 is used by platform.
*/
hd.hd_phys_address = hpet_address;
hd.hd_address = hpet_virt_address;
hd.hd_nirqs = ntimer;
hd.hd_flags = HPET_DATA_PLATFORM;
hpet_reserve_timer(&hd, 0);
#ifdef CONFIG_HPET_EMULATE_RTC
hpet_reserve_timer(&hd, 1);
#endif
hd.hd_irq[0] = HPET_LEGACY_8254;
hd.hd_irq[1] = HPET_LEGACY_RTC;
if (ntimer > 2) {
struct hpet __iomem *hpet;
struct hpet_timer __iomem *timer;
int i;
hpet = hpet_virt_address;
for (i = 2, timer = &hpet->hpet_timers[2]; i < ntimer;
timer++, i++)
hd.hd_irq[i] = (timer->hpet_config &
Tn_INT_ROUTE_CNF_MASK) >>
Tn_INT_ROUTE_CNF_SHIFT;
}
hpet_alloc(&hd);
}
#endif
#ifdef CONFIG_X86_LOCAL_APIC
if (hpet_use_timer)
wait_timer_tick = wait_hpet_tick;
#endif
return 0;
}
int hpet_reenable(void)
{
return hpet_timer_stop_set_go(hpet_tick);
}
int is_hpet_enabled(void)
{
return use_hpet;
}
int is_hpet_capable(void)
{
if (!boot_hpet_disable && hpet_address)
return 1;
return 0;
}
static int __init hpet_setup(char* str)
{
if (str) {
if (!strncmp("disable", str, 7))
boot_hpet_disable = 1;
}
return 1;
}
__setup("hpet=", hpet_setup);
#ifdef CONFIG_HPET_EMULATE_RTC
/* HPET in LegacyReplacement Mode eats up RTC interrupt line. When, HPET
* is enabled, we support RTC interrupt functionality in software.
* RTC has 3 kinds of interrupts:
* 1) Update Interrupt - generate an interrupt, every sec, when RTC clock
* is updated
* 2) Alarm Interrupt - generate an interrupt at a specific time of day
* 3) Periodic Interrupt - generate periodic interrupt, with frequencies
* 2Hz-8192Hz (2Hz-64Hz for non-root user) (all freqs in powers of 2)
* (1) and (2) above are implemented using polling at a frequency of
* 64 Hz. The exact frequency is a tradeoff between accuracy and interrupt
* overhead. (DEFAULT_RTC_INT_FREQ)
* For (3), we use interrupts at 64Hz or user specified periodic
* frequency, whichever is higher.
*/
#include <linux/mc146818rtc.h>
#include <linux/rtc.h>
#define DEFAULT_RTC_INT_FREQ 64
#define RTC_NUM_INTS 1
static unsigned long UIE_on;
static unsigned long prev_update_sec;
static unsigned long AIE_on;
static struct rtc_time alarm_time;
static unsigned long PIE_on;
static unsigned long PIE_freq = DEFAULT_RTC_INT_FREQ;
static unsigned long PIE_count;
static unsigned long hpet_rtc_int_freq; /* RTC interrupt frequency */
static unsigned int hpet_t1_cmp; /* cached comparator register */
/*
* Timer 1 for RTC, we do not use periodic interrupt feature,
* even if HPET supports periodic interrupts on Timer 1.
* The reason being, to set up a periodic interrupt in HPET, we need to
* stop the main counter. And if we do that everytime someone diables/enables
* RTC, we will have adverse effect on main kernel timer running on Timer 0.
* So, for the time being, simulate the periodic interrupt in software.
*
* hpet_rtc_timer_init() is called for the first time and during subsequent
* interuppts reinit happens through hpet_rtc_timer_reinit().
*/
int hpet_rtc_timer_init(void)
{
unsigned int cfg, cnt;
unsigned long flags;
if (!is_hpet_enabled())
return 0;
/*
* Set the counter 1 and enable the interrupts.
*/
if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ))
hpet_rtc_int_freq = PIE_freq;
else
hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
local_irq_save(flags);
cnt = hpet_readl(HPET_COUNTER);
cnt += ((hpet_tick*HZ)/hpet_rtc_int_freq);
hpet_writel(cnt, HPET_T1_CMP);
hpet_t1_cmp = cnt;
cfg = hpet_readl(HPET_T1_CFG);
cfg &= ~HPET_TN_PERIODIC;
cfg |= HPET_TN_ENABLE | HPET_TN_32BIT;
hpet_writel(cfg, HPET_T1_CFG);
local_irq_restore(flags);
return 1;
}
static void hpet_rtc_timer_reinit(void)
{
unsigned int cfg, cnt, ticks_per_int, lost_ints;
if (unlikely(!(PIE_on | AIE_on | UIE_on))) {
cfg = hpet_readl(HPET_T1_CFG);
cfg &= ~HPET_TN_ENABLE;
hpet_writel(cfg, HPET_T1_CFG);
return;
}
if (PIE_on && (PIE_freq > DEFAULT_RTC_INT_FREQ))
hpet_rtc_int_freq = PIE_freq;
else
hpet_rtc_int_freq = DEFAULT_RTC_INT_FREQ;
/* It is more accurate to use the comparator value than current count.*/
ticks_per_int = hpet_tick * HZ / hpet_rtc_int_freq;
hpet_t1_cmp += ticks_per_int;
hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
/*
* If the interrupt handler was delayed too long, the write above tries
* to schedule the next interrupt in the past and the hardware would
* not interrupt until the counter had wrapped around.
* So we have to check that the comparator wasn't set to a past time.
*/
cnt = hpet_readl(HPET_COUNTER);
if (unlikely((int)(cnt - hpet_t1_cmp) > 0)) {
lost_ints = (cnt - hpet_t1_cmp) / ticks_per_int + 1;
/* Make sure that, even with the time needed to execute
* this code, the next scheduled interrupt has been moved
* back to the future: */
lost_ints++;
hpet_t1_cmp += lost_ints * ticks_per_int;
hpet_writel(hpet_t1_cmp, HPET_T1_CMP);
if (PIE_on)
PIE_count += lost_ints;
printk(KERN_WARNING "rtc: lost some interrupts at %ldHz.\n",
hpet_rtc_int_freq);
}
}
/*
* The functions below are called from rtc driver.
* Return 0 if HPET is not being used.
* Otherwise do the necessary changes and return 1.
*/
int hpet_mask_rtc_irq_bit(unsigned long bit_mask)
{
if (!is_hpet_enabled())
return 0;
if (bit_mask & RTC_UIE)
UIE_on = 0;
if (bit_mask & RTC_PIE)
PIE_on = 0;
if (bit_mask & RTC_AIE)
AIE_on = 0;
return 1;
}
int hpet_set_rtc_irq_bit(unsigned long bit_mask)
{
int timer_init_reqd = 0;
if (!is_hpet_enabled())
return 0;
if (!(PIE_on | AIE_on | UIE_on))
timer_init_reqd = 1;
if (bit_mask & RTC_UIE) {
UIE_on = 1;
}
if (bit_mask & RTC_PIE) {
PIE_on = 1;
PIE_count = 0;
}
if (bit_mask & RTC_AIE) {
AIE_on = 1;
}
if (timer_init_reqd)
hpet_rtc_timer_init();
return 1;
}
int hpet_set_alarm_time(unsigned char hrs, unsigned char min, unsigned char sec)
{
if (!is_hpet_enabled())
return 0;
alarm_time.tm_hour = hrs;
alarm_time.tm_min = min;
alarm_time.tm_sec = sec;
return 1;
}
int hpet_set_periodic_freq(unsigned long freq)
{
if (!is_hpet_enabled())
return 0;
PIE_freq = freq;
PIE_count = 0;
return 1;
}
int hpet_rtc_dropped_irq(void)
{
if (!is_hpet_enabled())
return 0;
return 1;
}
irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id)
{
struct rtc_time curr_time;
unsigned long rtc_int_flag = 0;
int call_rtc_interrupt = 0;
hpet_rtc_timer_reinit();
if (UIE_on | AIE_on) {
rtc_get_rtc_time(&curr_time);
}
if (UIE_on) {
if (curr_time.tm_sec != prev_update_sec) {
/* Set update int info, call real rtc int routine */
call_rtc_interrupt = 1;
rtc_int_flag = RTC_UF;
prev_update_sec = curr_time.tm_sec;
}
}
if (PIE_on) {
PIE_count++;
if (PIE_count >= hpet_rtc_int_freq/PIE_freq) {
/* Set periodic int info, call real rtc int routine */
call_rtc_interrupt = 1;
rtc_int_flag |= RTC_PF;
PIE_count = 0;
}
}
if (AIE_on) {
if ((curr_time.tm_sec == alarm_time.tm_sec) &&
(curr_time.tm_min == alarm_time.tm_min) &&
(curr_time.tm_hour == alarm_time.tm_hour)) {
/* Set alarm int info, call real rtc int routine */
call_rtc_interrupt = 1;
rtc_int_flag |= RTC_AF;
}
}
if (call_rtc_interrupt) {
rtc_int_flag |= (RTC_IRQF | (RTC_NUM_INTS << 8));
rtc_interrupt(rtc_int_flag, dev_id);
}
return IRQ_HANDLED;
}
#endif

8
arch/i386/mach-default/setup.c
View File

@ -79,7 +79,12 @@ void __init trap_init_hook(void)
{
}
static struct irqaction irq0 = { timer_interrupt, IRQF_DISABLED, CPU_MASK_NONE, "timer", NULL, NULL};
static struct irqaction irq0 = {
.handler = timer_interrupt,
.flags = IRQF_DISABLED | IRQF_NOBALANCING,
.mask = CPU_MASK_NONE,
.name = "timer"
};
/**
* time_init_hook - do any specific initialisations for the system timer.
@ -90,6 +95,7 @@ static struct irqaction irq0 = { timer_interrupt, IRQF_DISABLED, CPU_MASK_NONE,
**/
void __init time_init_hook(void)
{
irq0.mask = cpumask_of_cpu(0);
setup_irq(0, &irq0);
}

38
drivers/acpi/processor_idle.c
View File

@ -39,6 +39,7 @@
#include <linux/moduleparam.h>
#include <linux/sched.h> /* need_resched() */
#include <linux/latency.h>
#include <linux/clockchips.h>
/*
* Include the apic definitions for x86 to have the APIC timer related defines
@ -274,12 +275,40 @@ static void acpi_timer_check_state(int state, struct acpi_processor *pr,
static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
{
#ifdef CONFIG_GENERIC_CLOCKEVENTS
unsigned long reason;
reason = pr->power.timer_broadcast_on_state < INT_MAX ?
CLOCK_EVT_NOTIFY_BROADCAST_ON : CLOCK_EVT_NOTIFY_BROADCAST_OFF;
clockevents_notify(reason, &pr->id);
#else
cpumask_t mask = cpumask_of_cpu(pr->id);
if (pr->power.timer_broadcast_on_state < INT_MAX)
on_each_cpu(switch_APIC_timer_to_ipi, &mask, 1, 1);
else
on_each_cpu(switch_ipi_to_APIC_timer, &mask, 1, 1);
#endif
}
/* Power(C) State timer broadcast control */
static void acpi_state_timer_broadcast(struct acpi_processor *pr,
struct acpi_processor_cx *cx,
int broadcast)
{
#ifdef CONFIG_GENERIC_CLOCKEVENTS
int state = cx - pr->power.states;
if (state >= pr->power.timer_broadcast_on_state) {
unsigned long reason;
reason = broadcast ? CLOCK_EVT_NOTIFY_BROADCAST_ENTER :
CLOCK_EVT_NOTIFY_BROADCAST_EXIT;
clockevents_notify(reason, &pr->id);
}
#endif
}
#else
@ -287,6 +316,11 @@ static void acpi_propagate_timer_broadcast(struct acpi_processor *pr)
static void acpi_timer_check_state(int state, struct acpi_processor *pr,
struct acpi_processor_cx *cstate) { }
static void acpi_propagate_timer_broadcast(struct acpi_processor *pr) { }
static void acpi_state_timer_broadcast(struct acpi_processor *pr,
struct acpi_processor_cx *cx,
int broadcast)
{
}
#endif
@ -434,6 +468,7 @@ static void acpi_processor_idle(void)
/* Get start time (ticks) */
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
/* Invoke C2 */
acpi_state_timer_broadcast(pr, cx, 1);
acpi_cstate_enter(cx);
/* Get end time (ticks) */
t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
@ -448,6 +483,7 @@ static void acpi_processor_idle(void)
/* Compute time (ticks) that we were actually asleep */
sleep_ticks =
ticks_elapsed(t1, t2) - cx->latency_ticks - C2_OVERHEAD;
acpi_state_timer_broadcast(pr, cx, 0);
break;
case ACPI_STATE_C3:
@ -469,6 +505,7 @@ static void acpi_processor_idle(void)
/* Get start time (ticks) */
t1 = inl(acpi_gbl_FADT.xpm_timer_block.address);
/* Invoke C3 */
acpi_state_timer_broadcast(pr, cx, 1);
acpi_cstate_enter(cx);
/* Get end time (ticks) */
t2 = inl(acpi_gbl_FADT.xpm_timer_block.address);
@ -488,6 +525,7 @@ static void acpi_processor_idle(void)
/* Compute time (ticks) that we were actually asleep */
sleep_ticks =
ticks_elapsed(t1, t2) - cx->latency_ticks - C3_OVERHEAD;
acpi_state_timer_broadcast(pr, cx, 0);
break;
default:

5
include/asm-i386/apic.h
View File

@ -113,14 +113,9 @@ extern void smp_local_timer_interrupt (void);
extern void setup_boot_APIC_clock (void);
extern void setup_secondary_APIC_clock (void);
extern int APIC_init_uniprocessor (void);
extern void disable_APIC_timer(void);
extern void enable_APIC_timer(void);
extern void enable_NMI_through_LVT0 (void * dummy);
void smp_send_timer_broadcast_ipi(void);
void switch_APIC_timer_to_ipi(void *cpumask);
void switch_ipi_to_APIC_timer(void *cpumask);
#define ARCH_APICTIMER_STOPS_ON_C3 1
extern int timer_over_8254;

16
include/asm-i386/hpet.h
View File

@ -90,16 +90,19 @@
#define HPET_MIN_PERIOD (100000UL)
#define HPET_TICK_RATE (HZ * 100000UL)
extern unsigned long hpet_tick; /* hpet clks count per tick */
extern unsigned long hpet_address; /* hpet memory map physical address */
extern int hpet_use_timer;
extern int is_hpet_enabled(void);
#ifdef CONFIG_X86_64
extern unsigned long hpet_tick; /* hpet clks count per tick */
extern int hpet_use_timer;
extern int hpet_rtc_timer_init(void);
extern int hpet_enable(void);
extern int hpet_reenable(void);
extern int is_hpet_enabled(void);
extern int is_hpet_capable(void);
extern int hpet_readl(unsigned long a);
#else
extern int hpet_enable(void);
#endif
#ifdef CONFIG_HPET_EMULATE_RTC
extern int hpet_mask_rtc_irq_bit(unsigned long bit_mask);
@ -110,5 +113,10 @@ extern int hpet_rtc_dropped_irq(void);
extern int hpet_rtc_timer_init(void);
extern irqreturn_t hpet_rtc_interrupt(int irq, void *dev_id);
#endif /* CONFIG_HPET_EMULATE_RTC */
#else
static inline int hpet_enable(void) { return 0; }
#endif /* CONFIG_HPET_TIMER */
#endif /* _I386_HPET_H */

15
include/asm-i386/i8253.h
View File

@ -1,6 +1,21 @@
#ifndef __ASM_I8253_H__
#define __ASM_I8253_H__
#include <linux/clockchips.h>
extern spinlock_t i8253_lock;
extern struct clock_event_device *global_clock_event;
/**
* pit_interrupt_hook - hook into timer tick
* @regs: standard registers from interrupt
*
* Call the global clock event handler.
**/
static inline void pit_interrupt_hook(void)
{
global_clock_event->event_handler(global_clock_event);
}
#endif /* __ASM_I8253_H__ */

78
include/asm-i386/mach-default/do_timer.h
View File

@ -1,86 +1,16 @@
/* defines for inline arch setup functions */
#include <linux/clockchips.h>
#include <asm/apic.h>
#include <asm/i8259.h>
#include <asm/i8253.h>
/**
* do_timer_interrupt_hook - hook into timer tick
* @regs: standard registers from interrupt
*
* Description:
* This hook is called immediately after the timer interrupt is ack'd.
* It's primary purpose is to allow architectures that don't possess
* individual per CPU clocks (like the CPU APICs supply) to broadcast the
* timer interrupt as a means of triggering reschedules etc.
* Call the pit clock event handler. see asm/i8253.h
**/
static inline void do_timer_interrupt_hook(void)
{
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode_vm(get_irq_regs()));
#endif
/*
* In the SMP case we use the local APIC timer interrupt to do the
* profiling, except when we simulate SMP mode on a uniprocessor
* system, in that case we have to call the local interrupt handler.
*/
#ifndef CONFIG_X86_LOCAL_APIC
profile_tick(CPU_PROFILING);
#else
if (!using_apic_timer)
smp_local_timer_interrupt();
#endif
}
/* you can safely undefine this if you don't have the Neptune chipset */
#define BUGGY_NEPTUN_TIMER
/**
* do_timer_overflow - process a detected timer overflow condition
* @count: hardware timer interrupt count on overflow
*
* Description:
* This call is invoked when the jiffies count has not incremented but
* the hardware timer interrupt has. It means that a timer tick interrupt
* came along while the previous one was pending, thus a tick was missed
**/
static inline int do_timer_overflow(int count)
{
int i;
spin_lock(&i8259A_lock);
/*
* This is tricky when I/O APICs are used;
* see do_timer_interrupt().
*/
i = inb(0x20);
spin_unlock(&i8259A_lock);
/* assumption about timer being IRQ0 */
if (i & 0x01) {
/*
* We cannot detect lost timer interrupts ...
* well, that's why we call them lost, don't we? :)
* [hmm, on the Pentium and Alpha we can ... sort of]
*/
count -= LATCH;
} else {
#ifdef BUGGY_NEPTUN_TIMER
/*
* for the Neptun bug we know that the 'latch'
* command doesn't latch the high and low value
* of the counter atomically. Thus we have to
* substract 256 from the counter
* ... funny, isnt it? :)
*/
count -= 256;
#else
printk("do_slow_gettimeoffset(): hardware timer problem?\n");
#endif
}
return count;
pit_interrupt_hook();
}

29
include/asm-i386/mach-voyager/do_timer.h
View File

@ -1,25 +1,18 @@
/* defines for inline arch setup functions */
#include <asm/voyager.h>
#include <linux/clockchips.h>
#include <asm/voyager.h>
#include <asm/i8253.h>
/**
* do_timer_interrupt_hook - hook into timer tick
* @regs: standard registers from interrupt
*
* Call the pit clock event handler. see asm/i8253.h
**/
static inline void do_timer_interrupt_hook(void)
{
do_timer(1);
#ifndef CONFIG_SMP
update_process_times(user_mode_vm(irq_regs));
#endif
pit_interrupt_hook();
voyager_timer_interrupt();
}
static inline int do_timer_overflow(int count)
{
/* can't read the ISR, just assume 1 tick
overflow */
if(count > LATCH || count < 0) {
printk(KERN_ERR "VOYAGER PROBLEM: count is %d, latch is %d\n", count, LATCH);
count = LATCH;
}
count -= LATCH;
return count;
}

1
include/asm-i386/mpspec.h
View File

@ -23,7 +23,6 @@ extern struct mpc_config_intsrc mp_irqs [MAX_IRQ_SOURCES];
extern int mpc_default_type;
extern unsigned long mp_lapic_addr;
extern int pic_mode;
extern int using_apic_timer;
#ifdef CONFIG_ACPI
extern void mp_register_lapic (u8 id, u8 enabled);