From: Venkatesh Pallipadi i386 generic subarchitecture requires explicit dmi strings or command line to enable bigsmp mode. The patch below removes that restriction, and uses bigsmp as soon as it finds more than 8 logical CPUs, Intel processors and xAPIC support. Signed-off-by: Venkatesh Pallipadi Signed-off-by: Andrew Morton --- arch/i386/kernel/acpi/boot.c | 3 +++ arch/i386/kernel/mpparse.c | 9 +++++++++ arch/i386/kernel/setup.c | 7 ++++++- arch/i386/mach-generic/bigsmp.c | 5 ++++- arch/i386/mach-generic/probe.c | 20 ++++++++++++++++++++ include/asm-i386/apicdef.h | 1 + include/asm-i386/mach-generic/mach_apic.h | 2 ++ include/asm-i386/mpspec.h | 1 + 8 files changed, 46 insertions(+), 2 deletions(-) diff -puN arch/i386/kernel/acpi/boot.c~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 arch/i386/kernel/acpi/boot.c --- devel/arch/i386/kernel/acpi/boot.c~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 2005-08-05 00:40:45.000000000 -0700 +++ devel-akpm/arch/i386/kernel/acpi/boot.c 2005-08-05 00:40:45.000000000 -0700 @@ -827,6 +827,9 @@ static void __init acpi_process_madt(voi if (!error) { acpi_lapic = 1; +#ifdef CONFIG_X86_GENERICARCH + generic_bigsmp_probe(); +#endif /* * Parse MADT IO-APIC entries */ diff -puN arch/i386/kernel/mpparse.c~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 arch/i386/kernel/mpparse.c --- devel/arch/i386/kernel/mpparse.c~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 2005-08-05 00:40:45.000000000 -0700 +++ devel-akpm/arch/i386/kernel/mpparse.c 2005-08-05 00:40:45.000000000 -0700 @@ -65,6 +65,8 @@ int nr_ioapics; int pic_mode; unsigned long mp_lapic_addr; +unsigned int def_to_bigsmp = 0; + /* Processor that is doing the boot up */ unsigned int boot_cpu_physical_apicid = -1U; /* Internal processor count */ @@ -213,6 +215,13 @@ static void __init MP_processor_info (st ver = 0x10; } apic_version[m->mpc_apicid] = ver; + if ((num_processors > 8) && + APIC_XAPIC(ver) && + (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL)) + def_to_bigsmp = 1; + else + def_to_bigsmp = 0; + bios_cpu_apicid[num_processors - 1] = m->mpc_apicid; } diff -puN arch/i386/kernel/setup.c~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 arch/i386/kernel/setup.c --- devel/arch/i386/kernel/setup.c~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 2005-08-05 00:40:45.000000000 -0700 +++ devel-akpm/arch/i386/kernel/setup.c 2005-08-05 00:40:45.000000000 -0700 @@ -1585,8 +1585,13 @@ void __init setup_arch(char **cmdline_p) */ acpi_boot_table_init(); acpi_boot_init(); -#endif +#if defined(CONFIG_SMP) && defined(CONFIG_X86_PC) + if (def_to_bigsmp) { + printk(KERN_WARNING "More than 8 CPUs detected and CONFIG_X86_PC cannot handle it.\n Use CONFIG_X86_GENERICARCH or CONFIG_X86_BIGSMP.\n"); + } +#endif +#endif #ifdef CONFIG_X86_LOCAL_APIC if (smp_found_config) get_smp_config(); diff -puN arch/i386/mach-generic/bigsmp.c~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 arch/i386/mach-generic/bigsmp.c --- devel/arch/i386/mach-generic/bigsmp.c~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 2005-08-05 00:40:45.000000000 -0700 +++ devel-akpm/arch/i386/mach-generic/bigsmp.c 2005-08-05 00:40:45.000000000 -0700 @@ -47,7 +47,10 @@ static struct dmi_system_id __initdata b static __init int probe_bigsmp(void) { - dmi_check_system(bigsmp_dmi_table); + if (def_to_bigsmp) + dmi_bigsmp = 1; + else + dmi_check_system(bigsmp_dmi_table); return dmi_bigsmp; } diff -puN arch/i386/mach-generic/probe.c~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 arch/i386/mach-generic/probe.c --- devel/arch/i386/mach-generic/probe.c~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 2005-08-05 00:40:45.000000000 -0700 +++ devel-akpm/arch/i386/mach-generic/probe.c 2005-08-05 00:40:45.000000000 -0700 @@ -30,6 +30,25 @@ struct genapic *apic_probe[] __initdata NULL, }; +static int cmdline_apic; + +void __init generic_bigsmp_probe(void) +{ + /* + * This routine is used to switch to bigsmp mode when + * - There is no apic= option specified by the user + * - generic_apic_probe() has choosen apic_default as the sub_arch + * - we find more than 8 CPUs in acpi LAPIC listing with xAPIC support + */ + + if (!cmdline_apic && genapic == &apic_default) + if (apic_bigsmp.probe()) { + genapic = &apic_bigsmp; + printk(KERN_INFO "Overriding APIC driver with %s\n", + genapic->name); + } +} + void __init generic_apic_probe(char *command_line) { char *s; @@ -52,6 +71,7 @@ void __init generic_apic_probe(char *com if (!changed) printk(KERN_ERR "Unknown genapic `%s' specified.\n", s); *p = old; + cmdline_apic = changed; } for (i = 0; !changed && apic_probe[i]; i++) { if (apic_probe[i]->probe()) { diff -puN include/asm-i386/apicdef.h~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 include/asm-i386/apicdef.h --- devel/include/asm-i386/apicdef.h~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 2005-08-05 00:40:45.000000000 -0700 +++ devel-akpm/include/asm-i386/apicdef.h 2005-08-05 00:40:45.000000000 -0700 @@ -16,6 +16,7 @@ #define GET_APIC_VERSION(x) ((x)&0xFF) #define GET_APIC_MAXLVT(x) (((x)>>16)&0xFF) #define APIC_INTEGRATED(x) ((x)&0xF0) +#define APIC_XAPIC(x) ((x) >= 0x14) #define APIC_TASKPRI 0x80 #define APIC_TPRI_MASK 0xFF #define APIC_ARBPRI 0x90 diff -puN include/asm-i386/mach-generic/mach_apic.h~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 include/asm-i386/mach-generic/mach_apic.h --- devel/include/asm-i386/mach-generic/mach_apic.h~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 2005-08-05 00:40:45.000000000 -0700 +++ devel-akpm/include/asm-i386/mach-generic/mach_apic.h 2005-08-05 00:40:45.000000000 -0700 @@ -28,4 +28,6 @@ #define enable_apic_mode (genapic->enable_apic_mode) #define phys_pkg_id (genapic->phys_pkg_id) +extern void generic_bigsmp_probe(void); + #endif /* __ASM_MACH_APIC_H */ diff -puN include/asm-i386/mpspec.h~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 include/asm-i386/mpspec.h --- devel/include/asm-i386/mpspec.h~x86-automatically-enable-bigsmp-when-we-have-more-than-8-cpus-2 2005-08-05 00:40:45.000000000 -0700 +++ devel-akpm/include/asm-i386/mpspec.h 2005-08-05 00:40:45.000000000 -0700 @@ -11,6 +11,7 @@ extern int mp_bus_id_to_local [MAX_MP_BU extern int quad_local_to_mp_bus_id [NR_CPUS/4][4]; extern int mp_bus_id_to_pci_bus [MAX_MP_BUSSES]; +extern unsigned int def_to_bigsmp; extern unsigned int boot_cpu_physical_apicid; extern int smp_found_config; extern void find_smp_config (void); _