apic_64.c

linux 内核源代码

	unsigned int value, maxlvt;
	int i, j;

	value = apic_read(APIC_LVR);

	BUILD_BUG_ON((SPURIOUS_APIC_VECTOR & 0x0f) != 0x0f);

	/*
	 * 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(APIC_TASKPRI, value);

	/*
	 * After a crash, we no longer service the interrupts and a pending
	 * interrupt from previous kernel might still have ISR bit set.
	 *
	 * Most probably by now CPU has serviced that pending interrupt and
	 * it might not have done the ack_APIC_irq() because it thought,
	 * interrupt came from i8259 as ExtInt. LAPIC did not get EOI so it
	 * does not clear the ISR bit and cpu thinks it has already serivced
	 * the interrupt. Hence a vector might get locked. It was noticed
	 * for timer irq (vector 0x31). Issue an extra EOI to clear ISR.
	 */
	for (i = APIC_ISR_NR - 1; i >= 0; i--) {
		value = apic_read(APIC_ISR + i*0x10);
		for (j = 31; j >= 0; j--) {
			if (value & (1<<j))
				ack_APIC_irq();
		}
	}

	/*
	 * 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;

	/* We always use processor focus */

	/*
	 * Set spurious IRQ vector
	 */
	value |= SPURIOUS_APIC_VECTOR;
	apic_write(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() && !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(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(APIC_LVT1, value);

	{
		unsigned oldvalue;
		maxlvt = get_maxlvt();
		oldvalue = apic_read(APIC_ESR);
		value = ERROR_APIC_VECTOR;      // enables sending errors
		apic_write(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();
	setup_apic_nmi_watchdog(NULL);
	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;
	int maxlvt;

	if (!apic_pm_state.active)
		return 0;

	maxlvt = get_maxlvt();

	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);
	if (maxlvt >= 4)
		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);
#ifdef CONFIG_X86_MCE_INTEL
	if (maxlvt >= 5)
		apic_pm_state.apic_thmr = apic_read(APIC_LVTTHMR);
#endif
	local_irq_save(flags);
	disable_local_APIC();
	local_irq_restore(flags);
	return 0;
}

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

	if (!apic_pm_state.active)
		return 0;

	maxlvt = get_maxlvt();

	local_irq_save(flags);
	rdmsr(MSR_IA32_APICBASE, l, h);
	l &= ~MSR_IA32_APICBASE_BASE;
	l |= MSR_IA32_APICBASE_ENABLE | mp_lapic_addr;
	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);
#ifdef CONFIG_X86_MCE_INTEL
	if (maxlvt >= 5)
		apic_write(APIC_LVTTHMR, apic_pm_state.apic_thmr);
#endif
	if (maxlvt >= 4)
		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)
		return 0;
	/* XXX: remove suspend/resume procs if !apic_pm_state.active? */
	error = sysdev_class_register(&lapic_sysclass);
	if (!error)
		error = sysdev_register(&device_lapic);
	return error;
}
device_initcall(init_lapic_sysfs);

#else	/* CONFIG_PM */

static void apic_pm_activate(void) { }

#endif	/* CONFIG_PM */

static int __init apic_set_verbosity(char *str)
{
	if (str == NULL)  {
		skip_ioapic_setup = 0;
		ioapic_force = 1;
		return 0;
	}
	if (strcmp("debug", str) == 0)
		apic_verbosity = APIC_DEBUG;
	else if (strcmp("verbose", str) == 0)
		apic_verbosity = APIC_VERBOSE;
	else {
		printk(KERN_WARNING "APIC Verbosity level %s not recognised"
				" use apic=verbose or apic=debug\n", str);
		return -EINVAL;
	}

	return 0;
}
early_param("apic", apic_set_verbosity);

/*
 * Detect and enable local APICs on non-SMP boards.
 * Original code written by Keir Fraser.
 * On AMD64 we trust the BIOS - if it says no APIC it is likely
 * not correctly set up (usually the APIC timer won't work etc.)
 */

static int __init detect_init_APIC (void)
{
	if (!cpu_has_apic) {
		printk(KERN_INFO "No local APIC present\n");
		return -1;
	}

	mp_lapic_addr = APIC_DEFAULT_PHYS_BASE;
	boot_cpu_id = 0;
	return 0;
}

#ifdef CONFIG_X86_IO_APIC
static struct resource * __init ioapic_setup_resources(void)
{
#define IOAPIC_RESOURCE_NAME_SIZE 11
	unsigned long n;
	struct resource *res;
	char *mem;
	int i;

	if (nr_ioapics <= 0)
		return NULL;

	n = IOAPIC_RESOURCE_NAME_SIZE + sizeof(struct resource);
	n *= nr_ioapics;

	mem = alloc_bootmem(n);
	res = (void *)mem;

	if (mem != NULL) {
		memset(mem, 0, n);
		mem += sizeof(struct resource) * nr_ioapics;

		for (i = 0; i < nr_ioapics; i++) {
			res[i].name = mem;
			res[i].flags = IORESOURCE_MEM | IORESOURCE_BUSY;
			sprintf(mem,  "IOAPIC %u", i);
			mem += IOAPIC_RESOURCE_NAME_SIZE;
		}
	}

	ioapic_resources = res;

	return res;
}

static int __init ioapic_insert_resources(void)
{
	int i;
	struct resource *r = ioapic_resources;

	if (!r) {
		printk("IO APIC resources could be not be allocated.\n");
		return -1;
	}

	for (i = 0; i < nr_ioapics; i++) {
		insert_resource(&iomem_resource, r);
		r++;
	}

	return 0;
}

/* Insert the IO APIC resources after PCI initialization has occured to handle
 * IO APICS that are mapped in on a BAR in PCI space. */
late_initcall(ioapic_insert_resources);
#endif

void __init init_apic_mappings(void)
{
	unsigned long apic_phys;

	/*
	 * If no local APIC can be found then set up a fake all
	 * zeroes page to simulate the local APIC and another
	 * one for the IO-APIC.
	 */
	if (!smp_found_config && detect_init_APIC()) {
		apic_phys = (unsigned long) alloc_bootmem_pages(PAGE_SIZE);
		apic_phys = __pa(apic_phys);
	} else
		apic_phys = mp_lapic_addr;

	set_fixmap_nocache(FIX_APIC_BASE, apic_phys);
	apic_printk(APIC_VERBOSE, "mapped APIC to %16lx (%16lx)\n",
				APIC_BASE, apic_phys);

	/* Put local APIC into the resource map. */
	lapic_resource.start = apic_phys;
	lapic_resource.end = lapic_resource.start + PAGE_SIZE - 1;
	insert_resource(&iomem_resource, &lapic_resource);

	/*
	 * Fetch the APIC ID of the BSP in case we have a
	 * default configuration (or the MP table is broken).
	 */
	boot_cpu_id = GET_APIC_ID(apic_read(APIC_ID));

	{
		unsigned long ioapic_phys, idx = FIX_IO_APIC_BASE_0;
		int i;
		struct resource *ioapic_res;

		ioapic_res = ioapic_setup_resources();
		for (i = 0; i < nr_ioapics; i++) {
			if (smp_found_config) {
				ioapic_phys = mp_ioapics[i].mpc_apicaddr;
			} else {
				ioapic_phys = (unsigned long)
					alloc_bootmem_pages(PAGE_SIZE);
				ioapic_phys = __pa(ioapic_phys);
			}
			set_fixmap_nocache(idx, ioapic_phys);
			apic_printk(APIC_VERBOSE,
				    "mapped IOAPIC to %016lx (%016lx)\n",
				    __fix_to_virt(idx), ioapic_phys);
			idx++;

			if (ioapic_res != NULL) {
				ioapic_res->start = ioapic_phys;
				ioapic_res->end = ioapic_phys + (4 * 1024) - 1;
				ioapic_res++;
			}
		}
	}
}

/*
 * This function sets up the local APIC timer, with a timeout of
 * 'clocks' APIC bus clock. During calibration we actually call
 * this function twice on the boot CPU, once with a bogus timeout
 * value, second time for real. The other (noncalibrating) CPUs
 * call this function only once, with the real, calibrated value.
 *
 * We do reads before writes even if unnecessary, to get around the
 * P5 APIC double write bug.
 */

static void __setup_APIC_LVTT(unsigned int clocks, int oneshot, int irqen)