Commit f72dccac authored by Yinghai Lu's avatar Yinghai Lu Committed by Ingo Molnar
Browse files

x86: check_timer cleanup 



Impact: make check-timer more robust potentially solve boot fragility

For edge trigger io-apic routing, we already unmasked the pin via
setup_IO_APIC_irq(), so don't unmask it again.

Also call local_irq_disable() between timer_irq_works(), because it
calls local_irq_enable() inside.

Also remove not needed apic version reading for 64-bit

Signed-off-by: default avatarYinghai Lu <yinghai@kernel.org>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent abcaa2b8

arch/x86/kernel/io_apic.c

+22 −8
Original line number Diff line number Diff line
@@ -1657,7 +1657,7 @@ static void __init setup_timer_IRQ0_pin(unsigned int apic_id, unsigned int pin, 
	 * to the first CPU.

	 */

	entry.dest_mode = apic->irq_dest_mode;

	entry.mask = 1;					/* mask IRQ now */

	entry.mask = 0;			/* don't mask IRQ for edge */

	entry.dest = apic->cpu_mask_to_apicid(apic->target_cpus());

	entry.delivery_mode = apic->irq_delivery_mode;

	entry.polarity = 0;
@@ -2863,14 +2863,10 @@ static inline void __init check_timer(void) 
	int cpu = boot_cpu_id;

	int apic1, pin1, apic2, pin2;

	unsigned long flags;

	unsigned int ver;

	int no_pin1 = 0;



	local_irq_save(flags);



	ver = apic_read(APIC_LVR);

	ver = GET_APIC_VERSION(ver);



	/*

	 * get/set the timer IRQ vector:

	 */
@@ -2889,7 +2885,13 @@ static inline void __init check_timer(void) 
	apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_EXTINT);

	init_8259A(1);

#ifdef CONFIG_X86_32

	{

		unsigned int ver;



		ver = apic_read(APIC_LVR);

		ver = GET_APIC_VERSION(ver);

		timer_ack = (nmi_watchdog == NMI_IO_APIC && !APIC_INTEGRATED(ver));

	}

#endif



	pin1  = find_isa_irq_pin(0, mp_INT);
@@ -2928,8 +2930,17 @@ static inline void __init check_timer(void) 
		if (no_pin1) {

			add_pin_to_irq_cpu(cfg, cpu, apic1, pin1);

			setup_timer_IRQ0_pin(apic1, pin1, cfg->vector);

		}

		} else {

			/* for edge trigger, setup_IO_APIC_irq already

			 * leave it unmasked.

			 * so only need to unmask if it is level-trigger

			 * do we really have level trigger timer?

			 */

			int idx;

			idx = find_irq_entry(apic1, pin1, mp_INT);

			if (idx != -1 && irq_trigger(idx))

				unmask_IO_APIC_irq_desc(desc);

		}

		if (timer_irq_works()) {

			if (nmi_watchdog == NMI_IO_APIC) {

				setup_nmi();
@@ -2943,6 +2954,7 @@ static inline void __init check_timer(void) 
		if (intr_remapping_enabled)

			panic("timer doesn't work through Interrupt-remapped IO-APIC");

#endif

		local_irq_disable();

		clear_IO_APIC_pin(apic1, pin1);

		if (!no_pin1)

			apic_printk(APIC_QUIET, KERN_ERR "..MP-BIOS bug: "
@@ -2957,7 +2969,6 @@ static inline void __init check_timer(void) 
		 */

		replace_pin_at_irq_cpu(cfg, cpu, apic1, pin1, apic2, pin2);

		setup_timer_IRQ0_pin(apic2, pin2, cfg->vector);

		unmask_IO_APIC_irq_desc(desc);

		enable_8259A_irq(0);

		if (timer_irq_works()) {

			apic_printk(APIC_QUIET, KERN_INFO "....... works.\n");
@@ -2972,6 +2983,7 @@ static inline void __init check_timer(void) 
		/*

		 * Cleanup, just in case ...

		 */

		local_irq_disable();

		disable_8259A_irq(0);

		clear_IO_APIC_pin(apic2, pin2);

		apic_printk(APIC_QUIET, KERN_INFO "....... failed.\n");
@@ -2997,6 +3009,7 @@ static inline void __init check_timer(void) 
		apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");

		goto out;

	}

	local_irq_disable();

	disable_8259A_irq(0);

	apic_write(APIC_LVT0, APIC_LVT_MASKED | APIC_DM_FIXED | cfg->vector);

	apic_printk(APIC_QUIET, KERN_INFO "..... failed.\n");
@@ -3014,6 +3027,7 @@ static inline void __init check_timer(void) 
		apic_printk(APIC_QUIET, KERN_INFO "..... works.\n");

		goto out;

	}

	local_irq_disable();

	apic_printk(APIC_QUIET, KERN_INFO "..... failed :(.\n");

	panic("IO-APIC + timer doesn't work!  Boot with apic=debug and send a "

		"report.  Then try booting with the 'noapic' option.\n");

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