From a36166c6ef45081fea6eeaf5ca785d7ed786b6e2 Mon Sep 17 00:00:00 2001 From: Fernando Luis Vazquez Cao Date: Wed, 9 May 2007 02:33:27 -0700 Subject: [PATCH] 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: Fernando Luis Vazquez Cao Cc: "Luck, Tony" Acked-by: Andi Kleen Cc: "Eric W. Biederman" Cc: Vivek Goyal Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- arch/i386/mach-generic/probe.c | 2 -- include/asm-i386/smp.h | 36 ++++++++++++++++++++-------------- 2 files changed, 21 insertions(+), 17 deletions(-) diff --git a/arch/i386/mach-generic/probe.c b/arch/i386/mach-generic/probe.c index a7b3999bb37..74f3da63442 100644 --- a/arch/i386/mach-generic/probe.c +++ b/arch/i386/mach-generic/probe.c @@ -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 diff --git a/include/asm-i386/smp.h b/include/asm-i386/smp.h index 3243fa6f455..0c713278706 100644 --- a/include/asm-i386/smp.h +++ b/include/asm-i386/smp.h @@ -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 -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 +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 -- 2.41.1