apic.c

linux-2.6.15.6

/*
 *	Local APIC handling, local APIC timers
 *
 *	(c) 1999, 2000 Ingo Molnar <[e-mail]>
 *
 *	Fixes
 *	Maciej W. Rozycki	:	Bits for genuine 82489DX APICs;
 *					thanks to Eric Gilmore
 *					and Rolf G. Tews
 *					for testing these extensively.
 *	Maciej W. Rozycki	:	Various updates and fixes.
 *	Mikael Pettersson	:	Power Management for UP-APIC.
 *	Pavel Machek and
 *	Mikael Pettersson	:	PM converted to driver model.
 */

#include <linux/config.h>
#include <linux/init.h>

#include <linux/mm.h>
#include <linux/delay.h>
#include <linux/bootmem.h>
#include <linux/smp_lock.h>
#include <linux/interrupt.h>
#include <linux/mc146818rtc.h>
#include <linux/kernel_stat.h>
#include <linux/sysdev.h>

#include <asm/atomic.h>
#include <asm/smp.h>
#include <asm/mtrr.h>
#include <asm/mpspec.h>
#include <asm/pgalloc.h>
#include <asm/mach_apic.h>
#include <asm/nmi.h>

int apic_verbosity;

int disable_apic_timer __initdata;

/* Using APIC to generate smp_local_timer_interrupt? */
int using_apic_timer = 0;

static DEFINE_PER_CPU(int, prof_multiplier) = 1;
static DEFINE_PER_CPU(int, prof_old_multiplier) = 1;
static DEFINE_PER_CPU(int, prof_counter) = 1;

static void apic_pm_activate(void);

void enable_NMI_through_LVT0 (void * dummy)
{
	unsigned int v, ver;
	
	ver = apic_read(APIC_LVR);
	ver = GET_APIC_VERSION(ver);
	v = APIC_DM_NMI;                        /* unmask and set to NMI */
	apic_write_around(APIC_LVT0, v);
}

int get_maxlvt(void)
{
	unsigned int v, ver, maxlvt;

	v = apic_read(APIC_LVR);
	ver = GET_APIC_VERSION(v);
	maxlvt = GET_APIC_MAXLVT(v);
	return maxlvt;
}

void clear_local_APIC(void)
{
	int maxlvt;
	unsigned int v;

	maxlvt = get_maxlvt();

	/*
	 * Masking an LVT entry on a P6 can trigger a local APIC error
	 * if the vector is zero. Mask LVTERR first to prevent this.
	 */
	if (maxlvt >= 3) {
		v = ERROR_APIC_VECTOR; /* any non-zero vector will do */
		apic_write_around(APIC_LVTERR, v | APIC_LVT_MASKED);
	}
	/*
	 * Careful: we have to set masks only first to deassert
	 * any level-triggered sources.
	 */
	v = apic_read(APIC_LVTT);
	apic_write_around(APIC_LVTT, v | APIC_LVT_MASKED);
	v = apic_read(APIC_LVT0);
	apic_write_around(APIC_LVT0, v | APIC_LVT_MASKED);
	v = apic_read(APIC_LVT1);
	apic_write_around(APIC_LVT1, v | APIC_LVT_MASKED);
	if (maxlvt >= 4) {
		v = apic_read(APIC_LVTPC);
		apic_write_around(APIC_LVTPC, v | APIC_LVT_MASKED);
	}

	/*
	 * Clean APIC state for other OSs:
	 */
	apic_write_around(APIC_LVTT, APIC_LVT_MASKED);
	apic_write_around(APIC_LVT0, APIC_LVT_MASKED);
	apic_write_around(APIC_LVT1, APIC_LVT_MASKED);
	if (maxlvt >= 3)
		apic_write_around(APIC_LVTERR, APIC_LVT_MASKED);
	if (maxlvt >= 4)
		apic_write_around(APIC_LVTPC, APIC_LVT_MASKED);
	v = GET_APIC_VERSION(apic_read(APIC_LVR));
	apic_write(APIC_ESR, 0);
	apic_read(APIC_ESR);
}

void __init connect_bsp_APIC(void)
{
	if (pic_mode) {
		/*
		 * Do not trust the local APIC being empty at bootup.
		 */
		clear_local_APIC();
		/*
		 * PIC mode, enable APIC mode in the IMCR, i.e.
		 * connect BSP's local APIC to INT and NMI lines.
		 */
		apic_printk(APIC_VERBOSE, "leaving PIC mode, enabling APIC mode.\n");
		outb(0x70, 0x22);
		outb(0x01, 0x23);
	}
}

void disconnect_bsp_APIC(int virt_wire_setup)
{
	if (pic_mode) {
		/*
		 * Put the board back into PIC mode (has an effect
		 * only on certain older boards).  Note that APIC
		 * interrupts, including IPIs, won't work beyond
		 * this point!  The only exception are INIT IPIs.
		 */
		apic_printk(APIC_QUIET, "disabling APIC mode, entering PIC mode.\n");
		outb(0x70, 0x22);
		outb(0x00, 0x23);
	}
	else {
		/* Go back to Virtual Wire compatibility mode */
		unsigned long value;

		/* For the spurious interrupt use vector F, and enable it */
		value = apic_read(APIC_SPIV);
		value &= ~APIC_VECTOR_MASK;
		value |= APIC_SPIV_APIC_ENABLED;
		value |= 0xf;
		apic_write_around(APIC_SPIV, value);

		if (!virt_wire_setup) {
			/* For LVT0 make it edge triggered, active high, external and enabled */
			value = apic_read(APIC_LVT0);
			value &= ~(APIC_MODE_MASK | APIC_SEND_PENDING |
				APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
				APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED );
			value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
			value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_EXTINT);
			apic_write_around(APIC_LVT0, value);
		}
		else {
			/* Disable LVT0 */
			apic_write_around(APIC_LVT0, APIC_LVT_MASKED);
		}

		/* For LVT1 make it edge triggered, active high, nmi and enabled */
		value = apic_read(APIC_LVT1);
		value &= ~(
			APIC_MODE_MASK | APIC_SEND_PENDING |
			APIC_INPUT_POLARITY | APIC_LVT_REMOTE_IRR |
			APIC_LVT_LEVEL_TRIGGER | APIC_LVT_MASKED);
		value |= APIC_LVT_REMOTE_IRR | APIC_SEND_PENDING;
		value = SET_APIC_DELIVERY_MODE(value, APIC_MODE_NMI);
		apic_write_around(APIC_LVT1, value);
	}
}

void disable_local_APIC(void)
{
	unsigned int value;

	clear_local_APIC();

	/*
	 * Disable APIC (implies clearing of registers
	 * for 82489DX!).
	 */
	value = apic_read(APIC_SPIV);
	value &= ~APIC_SPIV_APIC_ENABLED;
	apic_write_around(APIC_SPIV, value);
}

/*
 * This is to verify that we're looking at a real local APIC.
 * Check these against your board if the CPUs aren't getting
 * started for no apparent reason.
 */
int __init verify_local_APIC(void)
{
	unsigned int reg0, reg1;

	/*
	 * The version register is read-only in a real APIC.
	 */
	reg0 = apic_read(APIC_LVR);
	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg0);
	apic_write(APIC_LVR, reg0 ^ APIC_LVR_MASK);
	reg1 = apic_read(APIC_LVR);
	apic_printk(APIC_DEBUG, "Getting VERSION: %x\n", reg1);

	/*
	 * The two version reads above should print the same
	 * numbers.  If the second one is different, then we
	 * poke at a non-APIC.
	 */
	if (reg1 != reg0)
		return 0;

	/*
	 * Check if the version looks reasonably.
	 */
	reg1 = GET_APIC_VERSION(reg0);
	if (reg1 == 0x00 || reg1 == 0xff)
		return 0;
	reg1 = get_maxlvt();
	if (reg1 < 0x02 || reg1 == 0xff)
		return 0;

	/*
	 * The ID register is read/write in a real APIC.
	 */
	reg0 = apic_read(APIC_ID);
	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg0);
	apic_write(APIC_ID, reg0 ^ APIC_ID_MASK);
	reg1 = apic_read(APIC_ID);
	apic_printk(APIC_DEBUG, "Getting ID: %x\n", reg1);
	apic_write(APIC_ID, reg0);
	if (reg1 != (reg0 ^ APIC_ID_MASK))
		return 0;

	/*
	 * The next two are just to see if we have sane values.
	 * They're only really relevant if we're in Virtual Wire
	 * compatibility mode, but most boxes are anymore.
	 */
	reg0 = apic_read(APIC_LVT0);
	apic_printk(APIC_DEBUG,"Getting LVT0: %x\n", reg0);
	reg1 = apic_read(APIC_LVT1);
	apic_printk(APIC_DEBUG, "Getting LVT1: %x\n", reg1);

	return 1;
}

void __init sync_Arb_IDs(void)
{
	/* Unsupported on P4 - see Intel Dev. Manual Vol. 3, Ch. 8.6.1 */
	unsigned int ver = GET_APIC_VERSION(apic_read(APIC_LVR));
	if (ver >= 0x14)	/* P4 or higher */
		return;

	/*
	 * Wait for idle.
	 */
	apic_wait_icr_idle();

	apic_printk(APIC_DEBUG, "Synchronizing Arb IDs.\n");
	apic_write_around(APIC_ICR, APIC_DEST_ALLINC | APIC_INT_LEVELTRIG
				| APIC_DM_INIT);
}

extern void __error_in_apic_c (void);

/*
 * An initial setup of the virtual wire mode.
 */
void __init init_bsp_APIC(void)
{
	unsigned int value, ver;

	/*
	 * Don't do the setup now if we have a SMP BIOS as the
	 * through-I/O-APIC virtual wire mode might be active.
	 */
	if (smp_found_config || !cpu_has_apic)
		return;

	value = apic_read(APIC_LVR);
	ver = GET_APIC_VERSION(value);

	/*
	 * Do not trust the local APIC being empty at bootup.
	 */
	clear_local_APIC();

	/*
	 * Enable APIC.
	 */
	value = apic_read(APIC_SPIV);
	value &= ~APIC_VECTOR_MASK;
	value |= APIC_SPIV_APIC_ENABLED;
	value |= APIC_SPIV_FOCUS_DISABLED;
	value |= SPURIOUS_APIC_VECTOR;
	apic_write_around(APIC_SPIV, value);

	/*
	 * Set up the virtual wire mode.
	 */
	apic_write_around(APIC_LVT0, APIC_DM_EXTINT);
	value = APIC_DM_NMI;
	apic_write_around(APIC_LVT1, value);
}

void __cpuinit setup_local_APIC (void)
{
	unsigned int value, ver, maxlvt;

	value = apic_read(APIC_LVR);
	ver = GET_APIC_VERSION(value);

	if ((SPURIOUS_APIC_VECTOR & 0x0f) != 0x0f)
		__error_in_apic_c();

	/*
	 * Double-check whether this APIC is really registered.
	 * This is meaningless in clustered apic mode, so we skip it.
	 */
	if (!apic_id_registered())
		BUG();

	/*
	 * Intel recommends to set DFR, LDR and TPR before enabling
	 * an APIC.  See e.g. "AP-388 82489DX User's Manual" (Intel
	 * document number 292116).  So here it goes...
	 */
	init_apic_ldr();

	/*
	 * Set Task Priority to 'accept all'. We never change this
	 * later on.
	 */
	value = apic_read(APIC_TASKPRI);
	value &= ~APIC_TPRI_MASK;
	apic_write_around(APIC_TASKPRI, value);

	/*
	 * Now that we are all set up, enable the APIC
	 */
	value = apic_read(APIC_SPIV);
	value &= ~APIC_VECTOR_MASK;
	/*
	 * Enable APIC
	 */
	value |= APIC_SPIV_APIC_ENABLED;

	/*
	 * Some unknown Intel IO/APIC (or APIC) errata is biting us with
	 * certain networking cards. If high frequency interrupts are
	 * happening on a particular IOAPIC pin, plus the IOAPIC routing
	 * entry is masked/unmasked at a high rate as well then sooner or
	 * later IOAPIC line gets 'stuck', no more interrupts are received
	 * from the device. If focus CPU is disabled then the hang goes
	 * away, oh well :-(
	 *
	 * [ This bug can be reproduced easily with a level-triggered
	 *   PCI Ne2000 networking cards and PII/PIII processors, dual
	 *   BX chipset. ]
	 */
	/*
	 * Actually disabling the focus CPU check just makes the hang less
	 * frequent as it makes the interrupt distributon model be more
	 * like LRU than MRU (the short-term load is more even across CPUs).
	 * See also the comment in end_level_ioapic_irq().  --macro
	 */
#if 1
	/* Enable focus processor (bit==0) */
	value &= ~APIC_SPIV_FOCUS_DISABLED;
#else
	/* Disable focus processor (bit==1) */
	value |= APIC_SPIV_FOCUS_DISABLED;
#endif
	/*
	 * Set spurious IRQ vector
	 */
	value |= SPURIOUS_APIC_VECTOR;
	apic_write_around(APIC_SPIV, value);

	/*
	 * Set up LVT0, LVT1:
	 *
	 * set up through-local-APIC on the BP's LINT0. This is not
	 * strictly necessary in pure symmetric-IO mode, but sometimes
	 * we delegate interrupts to the 8259A.
	 */
	/*
	 * TODO: set up through-local-APIC from through-I/O-APIC? --macro
	 */
	value = apic_read(APIC_LVT0) & APIC_LVT_MASKED;
	if (!smp_processor_id() && (pic_mode || !value)) {
		value = APIC_DM_EXTINT;
		apic_printk(APIC_VERBOSE, "enabled ExtINT on CPU#%d\n", smp_processor_id());
	} else {
		value = APIC_DM_EXTINT | APIC_LVT_MASKED;
		apic_printk(APIC_VERBOSE, "masked ExtINT on CPU#%d\n", smp_processor_id());
	}
	apic_write_around(APIC_LVT0, value);

	/*
	 * only the BP should see the LINT1 NMI signal, obviously.
	 */
	if (!smp_processor_id())
		value = APIC_DM_NMI;
	else
		value = APIC_DM_NMI | APIC_LVT_MASKED;
	apic_write_around(APIC_LVT1, value);

	{
		unsigned oldvalue;
		maxlvt = get_maxlvt();
		oldvalue = apic_read(APIC_ESR);
		value = ERROR_APIC_VECTOR;      // enables sending errors
		apic_write_around(APIC_LVTERR, value);
		/*
		 * spec says clear errors after enabling vector.
		 */
		if (maxlvt > 3)
			apic_write(APIC_ESR, 0);
		value = apic_read(APIC_ESR);
		if (value != oldvalue)
			apic_printk(APIC_VERBOSE,
			"ESR value after enabling vector: %08x, after %08x\n",
			oldvalue, value);
	}

	nmi_watchdog_default();
	if (nmi_watchdog == NMI_LOCAL_APIC)
		setup_apic_nmi_watchdog();
	apic_pm_activate();
}

#ifdef CONFIG_PM

static struct {
	/* 'active' is true if the local APIC was enabled by us and
	   not the BIOS; this signifies that we are also responsible
	   for disabling it before entering apm/acpi suspend */
	int active;
	/* r/w apic fields */
	unsigned int apic_id;
	unsigned int apic_taskpri;
	unsigned int apic_ldr;
	unsigned int apic_dfr;
	unsigned int apic_spiv;
	unsigned int apic_lvtt;
	unsigned int apic_lvtpc;
	unsigned int apic_lvt0;
	unsigned int apic_lvt1;
	unsigned int apic_lvterr;
	unsigned int apic_tmict;
	unsigned int apic_tdcr;
	unsigned int apic_thmr;
} apic_pm_state;

static int lapic_suspend(struct sys_device *dev, pm_message_t state)
{
	unsigned long flags;

	if (!apic_pm_state.active)
		return 0;

	apic_pm_state.apic_id = apic_read(APIC_ID);
	apic_pm_state.apic_taskpri = apic_read(APIC_TASKPRI);
	apic_pm_state.apic_ldr = apic_read(APIC_LDR);
	apic_pm_state.apic_dfr = apic_read(APIC_DFR);
	apic_pm_state.apic_spiv = apic_read(APIC_SPIV);
	apic_pm_state.apic_lvtt = apic_read(APIC_LVTT);
	apic_pm_state.apic_lvtpc = apic_read(APIC_LVTPC);
	apic_pm_state.apic_lvt0 = apic_read(APIC_LVT0);
	apic_pm_state.apic_lvt1 = apic_read(APIC_LVT1);
	apic_pm_state.apic_lvterr = apic_read(APIC_LVTERR);
	apic_pm_state.apic_tmict = apic_read(APIC_TMICT);
	apic_pm_state.apic_tdcr = apic_read(APIC_TDCR);
	apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
	local_save_flags(flags);
	local_irq_disable();
	disable_local_APIC();
	local_irq_restore(flags);
	return 0;
}

static int lapic_resume(struct sys_device *dev)
{
	unsigned int l, h;
	unsigned long flags;

	if (!apic_pm_state.active)
		return 0;

	/* XXX: Pavel needs this for S3 resume, but can't explain why */
	set_fixmap_nocache(FIX_APIC_BASE, APIC_DEFAULT_PHYS_BASE);

	local_irq_save(flags);
	rdmsr(MSR_IA32_APICBASE, l, h);
	l &= ~MSR_IA32_APICBASE_BASE;
	l |= MSR_IA32_APICBASE_ENABLE | APIC_DEFAULT_PHYS_BASE;
	wrmsr(MSR_IA32_APICBASE, l, h);
	apic_write(APIC_LVTERR, ERROR_APIC_VECTOR | APIC_LVT_MASKED);
	apic_write(APIC_ID, apic_pm_state.apic_id);
	apic_write(APIC_DFR, apic_pm_state.apic_dfr);
	apic_write(APIC_LDR, apic_pm_state.apic_ldr);
	apic_write(APIC_TASKPRI, apic_pm_state.apic_taskpri);
	apic_write(APIC_SPIV, apic_pm_state.apic_spiv);
	apic_write(APIC_LVT0, apic_pm_state.apic_lvt0);
	apic_write(APIC_LVT1, apic_pm_state.apic_lvt1);
	apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
	apic_write(APIC_LVTPC, apic_pm_state.apic_lvtpc);
	apic_write(APIC_LVTT, apic_pm_state.apic_lvtt);
	apic_write(APIC_TDCR, apic_pm_state.apic_tdcr);
	apic_write(APIC_TMICT, apic_pm_state.apic_tmict);
	apic_write(APIC_ESR, 0);
	apic_read(APIC_ESR);
	apic_write(APIC_LVTERR, apic_pm_state.apic_lvterr);
	apic_write(APIC_ESR, 0);
	apic_read(APIC_ESR);
	local_irq_restore(flags);
	return 0;
}

static struct sysdev_class lapic_sysclass = {
	set_kset_name("lapic"),
	.resume		= lapic_resume,
	.suspend	= lapic_suspend,
};

static struct sys_device device_lapic = {
	.id		= 0,
	.cls		= &lapic_sysclass,
};

static void __cpuinit apic_pm_activate(void)
{
	apic_pm_state.active = 1;
}

static int __init init_lapic_sysfs(void)
{
	int error;
	if (!cpu_has_apic)