| /* |
| * Copyright 2004 James Cleverdon, IBM. |
| * Subject to the GNU Public License, v.2 |
| * |
| * Generic APIC sub-arch probe layer. |
| * |
| * Hacked for x86-64 by James Cleverdon from i386 architecture code by |
| * Martin Bligh, Andi Kleen, James Bottomley, John Stultz, and |
| * James Cleverdon. |
| */ |
| #include <linux/config.h> |
| #include <linux/threads.h> |
| #include <linux/cpumask.h> |
| #include <linux/string.h> |
| #include <linux/kernel.h> |
| #include <linux/ctype.h> |
| #include <linux/init.h> |
| #include <linux/module.h> |
| |
| #include <asm/smp.h> |
| #include <asm/ipi.h> |
| |
| #if defined(CONFIG_ACPI_BUS) |
| #include <acpi/acpi_bus.h> |
| #endif |
| |
| /* which logical CPU number maps to which CPU (physical APIC ID) */ |
| u8 x86_cpu_to_apicid[NR_CPUS] __read_mostly = { [0 ... NR_CPUS-1] = BAD_APICID }; |
| EXPORT_SYMBOL(x86_cpu_to_apicid); |
| 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; |
| |
| |
| /* |
| * Check the APIC IDs in bios_cpu_apicid and choose the APIC mode. |
| */ |
| void __init clustered_apic_check(void) |
| { |
| long i; |
| u8 clusters, max_cluster; |
| u8 id; |
| u8 cluster_cnt[NUM_APIC_CLUSTERS]; |
| int num_cpus = 0; |
| |
| #if defined(CONFIG_ACPI_BUS) |
| /* |
| * Some x86_64 machines use physical APIC mode regardless of how many |
| * procs/clusters are present (x86_64 ES7000 is an example). |
| */ |
| if (acpi_fadt.revision > FADT2_REVISION_ID) |
| if (acpi_fadt.force_apic_physical_destination_mode) { |
| genapic = &apic_cluster; |
| goto print; |
| } |
| #endif |
| |
| memset(cluster_cnt, 0, sizeof(cluster_cnt)); |
| for (i = 0; i < NR_CPUS; i++) { |
| id = bios_cpu_apicid[i]; |
| 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; |
| if (cluster_cnt[i] > max_cluster) |
| max_cluster = cluster_cnt[i]; |
| } |
| } |
| |
| /* |
| * If we have clusters <= 1 and CPUs <= 8 in cluster 0, then flat mode, |
| * else if max_cluster <= 4 and cluster_cnt[15] == 0, clustered logical |
| * else physical mode. |
| * (We don't use lowest priority delivery + HW APIC IRQ steering, so |
| * can ignore the clustered logical case and go straight to physical.) |
| */ |
| if (clusters <= 1 && max_cluster <= 8 && cluster_cnt[0] == max_cluster) |
| genapic = &apic_flat; |
| else |
| genapic = &apic_cluster; |
| |
| print: |
| printk(KERN_INFO "Setting APIC routing to %s\n", genapic->name); |
| } |
| |
| /* Same for both flat and clustered. */ |
| |
| void send_IPI_self(int vector) |
| { |
| __send_IPI_shortcut(APIC_DEST_SELF, vector, APIC_DEST_PHYSICAL); |
| } |