Commit ef4c59a4 authored by Thomas Gleixner's avatar Thomas Gleixner
Browse files

x86/smpboot: Cleanup ioapic handling 



smpboot is very creative with the ways to disable ioapic.

smpboot_clear_io_apic() smpboot_clear_io_apic_irqs() and
disable_ioapic_support() serve a similar purpose.

smpboot_clear_io_apic_irqs() is the most useless of all
functions as it clears a variable which has not been setup yet.

Aside of that it has the same ifdef mess and conditionals around the
ioapic related code, which can now be removed.

Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
Acked-by: default avatarBorislav Petkov <bp@alien8.de>
Cc: Jiang Liu <jiang.liu@linux.intel.com>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Tony Luck <tony.luck@intel.com>
Link: http://lkml.kernel.org/r/20150115211703.650280684@linutronix.de


Signed-off-by: default avatarThomas Gleixner <tglx@linutronix.de>
parent 35e4c6d3

arch/x86/kernel/smpboot.c

+7 −40
Original line number Diff line number Diff line
@@ -103,13 +103,6 @@ EXPORT_PER_CPU_SYMBOL(cpu_info); 


atomic_t init_deasserted;



static inline void smpboot_clear_io_apic_irqs(void)

{

#ifdef CONFIG_X86_IO_APIC

	io_apic_irqs = 0;

#endif

}



static inline void smpboot_setup_warm_reset_vector(unsigned long start_eip)

{

	unsigned long flags;
@@ -147,27 +140,6 @@ static inline void smpboot_restore_warm_reset_vector(void) 
	*((volatile u32 *)phys_to_virt(TRAMPOLINE_PHYS_LOW)) = 0;

}



static inline void __init smpboot_setup_io_apic(void)

{

#ifdef CONFIG_X86_IO_APIC

	/*

	 * Here we can be sure that there is an IO-APIC in the system. Let's

	 * go and set it up:

	 */

	if (!skip_ioapic_setup && nr_ioapics)

		setup_IO_APIC();

	else

		nr_ioapics = 0;

#endif

}



static inline void smpboot_clear_io_apic(void)

{

#ifdef CONFIG_X86_IO_APIC

	nr_ioapics = 0;

#endif

}



/*

 * Report back to the Boot Processor during boot time or to the caller processor

 * during CPU online.
@@ -1019,9 +991,10 @@ void arch_disable_smp_support(void) 
 */

static __init void disable_smp(void)

{

	disable_ioapic_support();



	init_cpu_present(cpumask_of(0));

	init_cpu_possible(cpumask_of(0));

	smpboot_clear_io_apic_irqs();



	if (smp_found_config)

		physid_set_mask_of_physid(boot_cpu_physical_apicid, &phys_cpu_present_map);
@@ -1105,7 +1078,6 @@ static int __init smp_sanity_check(unsigned max_cpus) 
				boot_cpu_physical_apicid);

			pr_err("... forcing use of dummy APIC emulation (tell your hw vendor)\n");

		}

		smpboot_clear_io_apic();

		disable_ioapic_support();

		return -1;

	}
@@ -1117,7 +1089,7 @@ static int __init smp_sanity_check(unsigned max_cpus) 
	 */

	if (!max_cpus) {

		pr_info("SMP mode deactivated\n");

		smpboot_clear_io_apic();

		disable_ioapic_support();



		connect_bsp_APIC();

		setup_local_APIC();
@@ -1191,18 +1163,15 @@ void __init native_smp_prepare_cpus(unsigned int max_cpus) 
	else

		cpu0_logical_apicid = GET_APIC_LOGICAL_ID(apic_read(APIC_LDR));



	/*

	 * Enable IO APIC before setting up error vector

	 */

	if (!skip_ioapic_setup && nr_ioapics)

	/* Enable IO APIC before setting up error vector */

	enable_IO_APIC();



	bsp_end_local_APIC_setup();

	smpboot_setup_io_apic();

	setup_IO_APIC();



	/*

	 * Set up local APIC timer on boot CPU.

	 */



	pr_info("CPU%d: ", 0);

	print_cpu_info(&cpu_data(0));

	x86_init.timers.setup_percpu_clockev();
@@ -1241,9 +1210,7 @@ void __init native_smp_cpus_done(unsigned int max_cpus) 


	nmi_selftest();

	impress_friends();

#ifdef CONFIG_X86_IO_APIC

	setup_ioapic_dest();

#endif

	mtrr_aps_init();

}

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