io_apic.c

优龙2410linux2.6.8内核源代码

	.shutdown 	= shutdown_level_ioapic,
	.enable 	= enable_level_ioapic,
	.disable 	= disable_level_ioapic,
	.ack 		= mask_and_ack_level_ioapic,
	.end 		= end_level_ioapic,
	.set_affinity 	= set_ioapic_affinity,
};

static inline void init_IO_APIC_traps(void)
{
	int irq;

	/*
	 * NOTE! The local APIC isn't very good at handling
	 * multiple interrupts at the same interrupt level.
	 * As the interrupt level is determined by taking the
	 * vector number and shifting that right by 4, we
	 * want to spread these out a bit so that they don't
	 * all fall in the same interrupt level.
	 *
	 * Also, we've got to be careful not to trash gate
	 * 0x80, because int 0x80 is hm, kind of importantish. ;)
	 */
	for (irq = 0; irq < NR_IRQS ; irq++) {
		int tmp = irq;
		if (use_pci_vector()) {
			if (!platform_legacy_irq(tmp))
				if ((tmp = vector_to_irq(tmp)) == -1)
					continue;
		}
		if (IO_APIC_IRQ(tmp) && !IO_APIC_VECTOR(tmp)) {
			/*
			 * Hmm.. We don't have an entry for this,
			 * so default to an old-fashioned 8259
			 * interrupt if we can..
			 */
			if (irq < 16)
				make_8259A_irq(irq);
			else
				/* Strange. Oh, well.. */
				irq_desc[irq].handler = &no_irq_type;
		}
	}
}

static void enable_lapic_irq (unsigned int irq)
{
	unsigned long v;

	v = apic_read(APIC_LVT0);
	apic_write_around(APIC_LVT0, v & ~APIC_LVT_MASKED);
}

static void disable_lapic_irq (unsigned int irq)
{
	unsigned long v;

	v = apic_read(APIC_LVT0);
	apic_write_around(APIC_LVT0, v | APIC_LVT_MASKED);
}

static void ack_lapic_irq (unsigned int irq)
{
	ack_APIC_irq();
}

static void end_lapic_irq (unsigned int i) { /* nothing */ }

static struct hw_interrupt_type lapic_irq_type = {
	.typename 	= "local-APIC-edge",
	.startup 	= NULL, /* startup_irq() not used for IRQ0 */
	.shutdown 	= NULL, /* shutdown_irq() not used for IRQ0 */
	.enable 	= enable_lapic_irq,
	.disable 	= disable_lapic_irq,
	.ack 		= ack_lapic_irq,
	.end 		= end_lapic_irq
};

static void setup_nmi (void)
{
	/*
 	 * Dirty trick to enable the NMI watchdog ...
	 * We put the 8259A master into AEOI mode and
	 * unmask on all local APICs LVT0 as NMI.
	 *
	 * The idea to use the 8259A in AEOI mode ('8259A Virtual Wire')
	 * is from Maciej W. Rozycki - so we do not have to EOI from
	 * the NMI handler or the timer interrupt.
	 */ 
	printk(KERN_INFO "activating NMI Watchdog ...");

	on_each_cpu(enable_NMI_through_LVT0, NULL, 1, 1);

	printk(" done.\n");
}

/*
 * This looks a bit hackish but it's about the only one way of sending
 * a few INTA cycles to 8259As and any associated glue logic.  ICR does
 * not support the ExtINT mode, unfortunately.  We need to send these
 * cycles as some i82489DX-based boards have glue logic that keeps the
 * 8259A interrupt line asserted until INTA.  --macro
 */
static inline void unlock_ExtINT_logic(void)
{
	int pin, i;
	struct IO_APIC_route_entry entry0, entry1;
	unsigned char save_control, save_freq_select;
	unsigned long flags;

	pin = find_isa_irq_pin(8, mp_INT);
	if (pin == -1)
		return;

	spin_lock_irqsave(&ioapic_lock, flags);
	*(((int *)&entry0) + 1) = io_apic_read(0, 0x11 + 2 * pin);
	*(((int *)&entry0) + 0) = io_apic_read(0, 0x10 + 2 * pin);
	spin_unlock_irqrestore(&ioapic_lock, flags);
	clear_IO_APIC_pin(0, pin);

	memset(&entry1, 0, sizeof(entry1));

	entry1.dest_mode = 0;			/* physical delivery */
	entry1.mask = 0;			/* unmask IRQ now */
	entry1.dest.physical.physical_dest = hard_smp_processor_id();
	entry1.delivery_mode = dest_ExtINT;
	entry1.polarity = entry0.polarity;
	entry1.trigger = 0;
	entry1.vector = 0;

	spin_lock_irqsave(&ioapic_lock, flags);
	io_apic_write(0, 0x11 + 2 * pin, *(((int *)&entry1) + 1));
	io_apic_write(0, 0x10 + 2 * pin, *(((int *)&entry1) + 0));
	spin_unlock_irqrestore(&ioapic_lock, flags);

	save_control = CMOS_READ(RTC_CONTROL);
	save_freq_select = CMOS_READ(RTC_FREQ_SELECT);
	CMOS_WRITE((save_freq_select & ~RTC_RATE_SELECT) | 0x6,
		   RTC_FREQ_SELECT);
	CMOS_WRITE(save_control | RTC_PIE, RTC_CONTROL);

	i = 100;
	while (i-- > 0) {
		mdelay(10);
		if ((CMOS_READ(RTC_INTR_FLAGS) & RTC_PF) == RTC_PF)
			i -= 10;
	}

	CMOS_WRITE(save_control, RTC_CONTROL);
	CMOS_WRITE(save_freq_select, RTC_FREQ_SELECT);
	clear_IO_APIC_pin(0, pin);

	spin_lock_irqsave(&ioapic_lock, flags);
	io_apic_write(0, 0x11 + 2 * pin, *(((int *)&entry0) + 1));
	io_apic_write(0, 0x10 + 2 * pin, *(((int *)&entry0) + 0));
	spin_unlock_irqrestore(&ioapic_lock, flags);
}

/*
 * This code may look a bit paranoid, but it's supposed to cooperate with
 * a wide range of boards and BIOS bugs.  Fortunately only the timer IRQ
 * is so screwy.  Thanks to Brian Perkins for testing/hacking this beast
 * fanatically on his truly buggy board.
 */
static inline void check_timer(void)
{
	int pin1, pin2;
	int vector;

	/*
	 * get/set the timer IRQ vector:
	 */
	disable_8259A_irq(0);
	vector = assign_irq_vector(0);
	set_intr_gate(vector, interrupt[0]);

	/*
	 * Subtle, code in do_timer_interrupt() expects an AEOI
	 * mode for the 8259A whenever interrupts are routed
	 * through I/O APICs.  Also IRQ0 has to be enabled in
	 * the 8259A which implies the virtual wire has to be
	 * disabled in the local APIC.
	 */
	apic_write_around(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);
	init_8259A(1);
	timer_ack = 1;
	enable_8259A_irq(0);

	pin1 = find_isa_irq_pin(0, mp_INT);
	pin2 = find_isa_irq_pin(0, mp_ExtINT);

	printk(KERN_INFO "..TIMER: vector=0x%02X pin1=%d pin2=%d\n", vector, pin1, pin2);

	if (pin1 != -1) {
		/*
		 * Ok, does IRQ0 through the IOAPIC work?
		 */
		unmask_IO_APIC_irq(0);
		if (timer_irq_works()) {
			if (nmi_watchdog == NMI_IO_APIC) {
				disable_8259A_irq(0);
				setup_nmi();
				enable_8259A_irq(0);
				check_nmi_watchdog();
			}
			return;
		}
		clear_IO_APIC_pin(0, pin1);
		printk(KERN_ERR "..MP-BIOS bug: 8254 timer not connected to IO-APIC\n");
	}

	printk(KERN_INFO "...trying to set up timer (IRQ0) through the 8259A ... ");
	if (pin2 != -1) {
		printk("\n..... (found pin %d) ...", pin2);
		/*
		 * legacy devices should be connected to IO APIC #0
		 */
		setup_ExtINT_IRQ0_pin(pin2, vector);
		if (timer_irq_works()) {
			printk("works.\n");
			if (pin1 != -1)
				replace_pin_at_irq(0, 0, pin1, 0, pin2);
			else
				add_pin_to_irq(0, 0, pin2);
			if (nmi_watchdog == NMI_IO_APIC) {
				setup_nmi();
				check_nmi_watchdog();
			}
			return;
		}
		/*
		 * Cleanup, just in case ...
		 */
		clear_IO_APIC_pin(0, pin2);
	}
	printk(" failed.\n");

	if (nmi_watchdog == NMI_IO_APIC) {
		printk(KERN_WARNING "timer doesn't work through the IO-APIC - disabling NMI Watchdog!\n");
		nmi_watchdog = 0;
	}

	printk(KERN_INFO "...trying to set up timer as Virtual Wire IRQ...");

	disable_8259A_irq(0);
	irq_desc[0].handler = &lapic_irq_type;
	apic_write_around(APIC_LVT0, APIC_DM_FIXED | vector);	/* Fixed mode */
	enable_8259A_irq(0);

	if (timer_irq_works()) {
		printk(" works.\n");
		return;
	}
	apic_write_around(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_FIXED | vector);
	printk(" failed.\n");

	printk(KERN_INFO "...trying to set up timer as ExtINT IRQ...");

	timer_ack = 0;
	init_8259A(0);
	make_8259A_irq(0);
	apic_write_around(APIC_LVT0, APIC_DM_EXTINT);

	unlock_ExtINT_logic();

	if (timer_irq_works()) {
		printk(" works.\n");
		return;
	}
	printk(" failed :(.\n");
	panic("IO-APIC + timer doesn't work! Try using the 'noapic' kernel parameter\n");
}

/*
 *
 * IRQ's that are handled by the PIC in the MPS IOAPIC case.
 * - IRQ2 is the cascade IRQ, and cannot be a io-apic IRQ.
 *   Linux doesn't really care, as it's not actually used
 *   for any interrupt handling anyway.
 */
#define PIC_IRQS	(1 << PIC_CASCADE_IR)

void __init setup_IO_APIC(void)
{
	enable_IO_APIC();

	if (acpi_ioapic)
		io_apic_irqs = ~0;	/* all IRQs go through IOAPIC */
	else
		io_apic_irqs = ~PIC_IRQS;

	printk("ENABLING IO-APIC IRQs\n");

	/*
	 * Set up IO-APIC IRQ routing.
	 */
	if (!acpi_ioapic)
		setup_ioapic_ids_from_mpc();
	sync_Arb_IDs();
	setup_IO_APIC_irqs();
	init_IO_APIC_traps();
	check_timer();
	if (!acpi_ioapic)
		print_IO_APIC();
}

/*
 *	Called after all the initialization is done. If we didnt find any
 *	APIC bugs then we can allow the modify fast path
 */
 
static int __init io_apic_bug_finalize(void)
{
	if(sis_apic_bug == -1)
		sis_apic_bug = 0;
	return 0;
}

late_initcall(io_apic_bug_finalize);

/* --------------------------------------------------------------------------
                          ACPI-based IOAPIC Configuration
   -------------------------------------------------------------------------- */

#ifdef CONFIG_ACPI_BOOT

int __init io_apic_get_unique_id (int ioapic, int apic_id)
{
	union IO_APIC_reg_00 reg_00;
	static physid_mask_t apic_id_map = PHYSID_MASK_NONE;
	physid_mask_t tmp;
	unsigned long flags;
	int i = 0;

	/*
	 * The P4 platform supports up to 256 APIC IDs on two separate APIC 
	 * buses (one for LAPICs, one for IOAPICs), where predecessors only 
	 * supports up to 16 on one shared APIC bus.
	 * 
	 * TBD: Expand LAPIC/IOAPIC support on P4-class systems to take full
	 *      advantage of new APIC bus architecture.
	 */

	if (physids_empty(apic_id_map))
		apic_id_map = ioapic_phys_id_map(phys_cpu_present_map);

	spin_lock_irqsave(&ioapic_lock, flags);
	reg_00.raw = io_apic_read(ioapic, 0);
	spin_unlock_irqrestore(&ioapic_lock, flags);

	if (apic_id >= get_physical_broadcast()) {
		printk(KERN_WARNING "IOAPIC[%d]: Invalid apic_id %d, trying "
			"%d\n", ioapic, apic_id, reg_00.bits.ID);
		apic_id = reg_00.bits.ID;
	}

	/*
	 * Every APIC in a system must have a unique ID or we get lots of nice 
	 * 'stuck on smp_invalidate_needed IPI wait' messages.
	 */
	if (check_apicid_used(apic_id_map, apic_id)) {

		for (i = 0; i < get_physical_broadcast(); i++) {
			if (!check_apicid_used(apic_id_map, i))
				break;
		}

		if (i == get_physical_broadcast())
			panic("Max apic_id exceeded!\n");

		printk(KERN_WARNING "IOAPIC[%d]: apic_id %d already used, "
			"trying %d\n", ioapic, apic_id, i);

		apic_id = i;
	} 

	tmp = apicid_to_cpu_present(apic_id);
	physids_or(apic_id_map, apic_id_map, tmp);

	if (reg_00.bits.ID != apic_id) {
		reg_00.bits.ID = apic_id;

		spin_lock_irqsave(&ioapic_lock, flags);
		io_apic_write(ioapic, 0, reg_00.raw);
		reg_00.raw = io_apic_read(ioapic, 0);
		spin_unlock_irqrestore(&ioapic_lock, flags);

		/* Sanity check */
		if (reg_00.bits.ID != apic_id)
			panic("IOAPIC[%d]: Unable change apic_id!\n", ioapic);
	}

	printk(KERN_INFO "IOAPIC[%d]: Assigned apic_id %d\n", ioapic, apic_id);

	return apic_id;
}


int __init io_apic_get_version (int ioapic)
{
	union IO_APIC_reg_01	reg_01;
	unsigned long flags;

	spin_lock_irqsave(&ioapic_lock, flags);
	reg_01.raw = io_apic_read(ioapic, 1);
	spin_unlock_irqrestore(&ioapic_lock, flags);

	return reg_01.bits.version;
}


int __init io_apic_get_redir_entries (int ioapic)
{
	union IO_APIC_reg_01	reg_01;
	unsigned long flags;

	spin_lock_irqsave(&ioapic_lock, flags);
	reg_01.raw = io_apic_read(ioapic, 1);
	spin_unlock_irqrestore(&ioapic_lock, flags);

	return reg_01.bits.entries;
}


int io_apic_set_pci_routing (int ioapic, int pin, int irq, int edge_level, int active_high_low)
{
	struct IO_APIC_route_entry entry;
	unsigned long flags;

	if (!IO_APIC_IRQ(irq)) {
		printk(KERN_ERR "IOAPIC[%d]: Invalid reference to IRQ 0\n",
			ioapic);
		return -EINVAL;
	}

	/*
	 * Generate a PCI IRQ routing entry and program the IOAPIC accordingly.
	 * Note that we mask (disable) IRQs now -- these get enabled when the
	 * corresponding device driver registers for this IRQ.
	 */

	memset(&entry,0,sizeof(entry));

	entry.delivery_mode = INT_DELIVERY_MODE;
	entry.dest_mode = INT_DEST_MODE;
	entry.dest.logical.logical_dest = cpu_mask_to_apicid(TARGET_CPUS);
	entry.trigger = edge_level;
	entry.polarity = active_high_low;
	entry.mask  = 1;

	/*
	 * IRQs < 16 are already in the irq_2_pin[] map
	 */
	if (irq >= 16)
		add_pin_to_irq(irq, ioapic, pin);

	entry.vector = assign_irq_vector(irq);

	Dprintk(KERN_DEBUG "IOAPIC[%d]: Set PCI routing entry (%d-%d -> 0x%x -> "
		"IRQ %d Mode:%i Active:%i)\n", ioapic, 
		mp_ioapics[ioapic].mpc_apicid, pin, entry.vector, irq, edge_level, active_high_low);

 	if (use_pci_vector() && !platform_legacy_irq(irq))
		irq = IO_APIC_VECTOR(irq);
	if (edge_level) {
		irq_desc[irq].handler = &ioapic_level_type;
	} else {
		irq_desc[irq].handler = &ioapic_edge_type;
	}

	set_intr_gate(entry.vector, interrupt[irq]);

	if (!ioapic && (irq < 16))
		disable_8259A_irq(irq);

	spin_lock_irqsave(&ioapic_lock, flags);
	io_apic_write(ioapic, 0x11+2*pin, *(((int *)&entry)+1));
	io_apic_write(ioapic, 0x10+2*pin, *(((int *)&entry)+0));
	spin_unlock_irqrestore(&ioapic_lock, flags);

	return 0;
}

#endif /*CONFIG_ACPI_BOOT*/