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Commit a36166c6 authored by Fernando Luis Vazquez Cao's avatar Fernando Luis Vazquez Cao Committed by Linus Torvalds
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Use the APIC to determine the hardware processor id - i386 



hard_smp_processor_id used to be just a macro that hard-coded
hard_smp_processor_id to 0 in the non SMP case.  When booting non SMP kernels
on hardware where the boot ioapic id is not 0 this turns out to be a problem.
This is happens frequently in the case of kdump and once in a great while in
the case of real hardware.

Use the APIC to determine the hardware processor id in both UP and SMP kernels
to fix this issue.

Notice that hard_smp_processor_id is only used by SMP code or by code that
works with apics so we do not need to handle the case when apics are not
present and hard_smp_processor_id should never be called there.

Signed-off-by: default avatarFernando Luis Vazquez Cao <fernando@oss.ntt.co.jp>
Cc: "Luck, Tony" <tony.luck@intel.com>
Acked-by: default avatarAndi Kleen <ak@suse.de>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: Vivek Goyal <vgoyal@in.ibm.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 2f4dfe20

arch/i386/mach-generic/probe.c

+0 −2
Original line number Diff line number Diff line
@@ -119,9 +119,7 @@ int __init acpi_madt_oem_check(char *oem_id, char *oem_table_id) 
	return 0;	

}



#ifdef CONFIG_SMP

int hard_smp_processor_id(void)

{

	return genapic->get_apic_id(*(unsigned long *)(APIC_BASE+APIC_ID));

}
 
#endif

include/asm-i386/smp.h

+21 −15
Original line number Diff line number Diff line
@@ -124,20 +124,6 @@ static inline int num_booting_cpus(void) 
	return cpus_weight(cpu_callout_map);

}



#ifdef CONFIG_X86_LOCAL_APIC



#ifdef APIC_DEFINITION

extern int hard_smp_processor_id(void);

#else

#include <mach_apicdef.h>

static inline int hard_smp_processor_id(void)

{

	/* we don't want to mark this access volatile - bad code generation */

	return GET_APIC_ID(*(unsigned long *)(APIC_BASE+APIC_ID));

}

#endif

#endif



extern int safe_smp_processor_id(void);

extern int __cpu_disable(void);

extern void __cpu_die(unsigned int cpu);
@@ -147,7 +133,6 @@ extern unsigned int num_processors; 


#else /* CONFIG_SMP */



#define hard_smp_processor_id()		0

#define safe_smp_processor_id()		0

#define cpu_physical_id(cpu)		boot_cpu_physical_apicid
@@ -157,6 +142,27 @@ extern unsigned int num_processors; 


#ifndef __ASSEMBLY__



#ifdef CONFIG_X86_LOCAL_APIC



#ifdef APIC_DEFINITION

extern int hard_smp_processor_id(void);

#else

#include <mach_apicdef.h>

static inline int hard_smp_processor_id(void)

{

	/* we don't want to mark this access volatile - bad code generation */

	return GET_APIC_ID(*(unsigned long *)(APIC_BASE+APIC_ID));

}

#endif /* APIC_DEFINITION */



#else /* CONFIG_X86_LOCAL_APIC */



#ifndef CONFIG_SMP

#define hard_smp_processor_id()		0

#endif



#endif /* CONFIG_X86_LOCAL_APIC */



extern u8 apicid_2_node[];



#ifdef CONFIG_X86_LOCAL_APIC