diff options
Diffstat (limited to 'arch/x86/kernel/apic/apic.c')
| -rw-r--r-- | arch/x86/kernel/apic/apic.c | 60 |
1 files changed, 57 insertions, 3 deletions
diff --git a/arch/x86/kernel/apic/apic.c b/arch/x86/kernel/apic/apic.c index a8c94bb6b528..2dc01c38ad8e 100644 --- a/arch/x86/kernel/apic/apic.c +++ b/arch/x86/kernel/apic/apic.c @@ -2021,7 +2021,53 @@ void disconnect_bsp_APIC(int virt_wire_setup) apic_write(APIC_LVT1, value); } -static int __generic_processor_info(int apicid, int version, bool enabled) +/* + * The number of allocated logical CPU IDs. Since logical CPU IDs are allocated + * contiguously, it equals to current allocated max logical CPU ID plus 1. + * All allocated CPU ID should be in [0, nr_logical_cpuidi), so the maximum of + * nr_logical_cpuids is nr_cpu_ids. + * + * NOTE: Reserve 0 for BSP. + */ +static int nr_logical_cpuids = 1; + +/* + * Used to store mapping between logical CPU IDs and APIC IDs. + */ +static int cpuid_to_apicid[] = { + [0 ... NR_CPUS - 1] = -1, +}; + +/* + * Should use this API to allocate logical CPU IDs to keep nr_logical_cpuids + * and cpuid_to_apicid[] synchronized. + */ +static int allocate_logical_cpuid(int apicid) +{ + int i; + + /* + * cpuid <-> apicid mapping is persistent, so when a cpu is up, + * check if the kernel has allocated a cpuid for it. + */ + for (i = 0; i < nr_logical_cpuids; i++) { + if (cpuid_to_apicid[i] == apicid) + return i; + } + + /* Allocate a new cpuid. */ + if (nr_logical_cpuids >= nr_cpu_ids) { + WARN_ONCE(1, "Only %d processors supported." + "Processor %d/0x%x and the rest are ignored.\n", + nr_cpu_ids - 1, nr_logical_cpuids, apicid); + return -1; + } + + cpuid_to_apicid[nr_logical_cpuids] = apicid; + return nr_logical_cpuids++; +} + +int __generic_processor_info(int apicid, int version, bool enabled) { int cpu, max = nr_cpu_ids; bool boot_cpu_detected = physid_isset(boot_cpu_physical_apicid, @@ -2096,8 +2142,16 @@ static int __generic_processor_info(int apicid, int version, bool enabled) * for BSP. */ cpu = 0; - } else - cpu = cpumask_next_zero(-1, cpu_present_mask); + + /* Logical cpuid 0 is reserved for BSP. */ + cpuid_to_apicid[0] = apicid; + } else { + cpu = allocate_logical_cpuid(apicid); + if (cpu < 0) { + disabled_cpus++; + return -EINVAL; + } + } /* * This can happen on physical hotplug. The sanity check at boot time |