diff options
Diffstat (limited to 'arch/x86_64/kernel/genapic.c')
| -rw-r--r-- | arch/x86_64/kernel/genapic.c | 33 |
1 files changed, 24 insertions, 9 deletions
diff --git a/arch/x86_64/kernel/genapic.c b/arch/x86_64/kernel/genapic.c index 69b9c25a8fc..30c843a5efd 100644 --- a/arch/x86_64/kernel/genapic.c +++ b/arch/x86_64/kernel/genapic.c @@ -31,6 +31,7 @@ u8 x86_cpu_to_log_apicid[NR_CPUS] = { [0 ... NR_CPUS-1] = BAD_APICID }; extern struct genapic apic_cluster; extern struct genapic apic_flat; +extern struct genapic apic_physflat; struct genapic *genapic = &apic_flat; @@ -44,12 +45,7 @@ void __init clustered_apic_check(void) u8 clusters, max_cluster; u8 id; u8 cluster_cnt[NUM_APIC_CLUSTERS]; - - if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) { - /* AMD always uses flat mode right now */ - genapic = &apic_flat; - goto print; - } + int num_cpus = 0; #if defined(CONFIG_ACPI_BUS) /* @@ -64,15 +60,34 @@ void __init clustered_apic_check(void) #endif memset(cluster_cnt, 0, sizeof(cluster_cnt)); - for (i = 0; i < NR_CPUS; i++) { id = bios_cpu_apicid[i]; - if (id != BAD_APICID) - cluster_cnt[APIC_CLUSTERID(id)]++; + if (id == BAD_APICID) + continue; + num_cpus++; + cluster_cnt[APIC_CLUSTERID(id)]++; } + /* Don't use clustered mode on AMD platforms. */ + if (boot_cpu_data.x86_vendor == X86_VENDOR_AMD) { + genapic = &apic_physflat; +#ifndef CONFIG_CPU_HOTPLUG + /* In the CPU hotplug case we cannot use broadcast mode + because that opens a race when a CPU is removed. + Stay at physflat mode in this case. + It is bad to do this unconditionally though. Once + we have ACPI platform support for CPU hotplug + we should detect hotplug capablity from ACPI tables and + only do this when really needed. -AK */ + if (num_cpus <= 8) + genapic = &apic_flat; +#endif + goto print; + } + clusters = 0; max_cluster = 0; + for (i = 0; i < NUM_APIC_CLUSTERS; i++) { if (cluster_cnt[i] > 0) { ++clusters; |