SAFE public projects git trees. - safe/jmp/linux-2.6/blob - arch/x86/kernel/smpboot.c

   1 #include <linux/init.h>
   2 #include <linux/smp.h>
   3 #include <linux/module.h>
   4
   5 /* Number of siblings per CPU package */
   6 int smp_num_siblings = 1;
   7 EXPORT_SYMBOL(smp_num_siblings);
   8
   9 /* Last level cache ID of each logical CPU */
  10 DEFINE_PER_CPU(u16, cpu_llc_id) = BAD_APICID;
  11
  12 /* bitmap of online cpus */
  13 cpumask_t cpu_online_map __read_mostly;
  14 EXPORT_SYMBOL(cpu_online_map);
  15
  16 cpumask_t cpu_callin_map;
  17 cpumask_t cpu_callout_map;
  18 cpumask_t cpu_possible_map;
  19 EXPORT_SYMBOL(cpu_possible_map);
  20
  21 /* representing HT siblings of each logical CPU */
  22 DEFINE_PER_CPU(cpumask_t, cpu_sibling_map);
  23 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
  24
  25 /* representing HT and core siblings of each logical CPU */
  26 DEFINE_PER_CPU(cpumask_t, cpu_core_map);
  27 EXPORT_PER_CPU_SYMBOL(cpu_core_map);
  28
  29 /* Per CPU bogomips and other parameters */
  30 DEFINE_PER_CPU_SHARED_ALIGNED(struct cpuinfo_x86, cpu_info);
  31 EXPORT_PER_CPU_SYMBOL(cpu_info);
  32 #ifdef CONFIG_HOTPLUG_CPU
  33
  34 int additional_cpus __initdata = -1;
  35
  36 static __init int setup_additional_cpus(char *s)
  37 {
  38         return s && get_option(&s, &additional_cpus) ? 0 : -EINVAL;
  39 }
  40 early_param("additional_cpus", setup_additional_cpus);
  41
  42 /*
  43  * cpu_possible_map should be static, it cannot change as cpu's
  44  * are onlined, or offlined. The reason is per-cpu data-structures
  45  * are allocated by some modules at init time, and dont expect to
  46  * do this dynamically on cpu arrival/departure.
  47  * cpu_present_map on the other hand can change dynamically.
  48  * In case when cpu_hotplug is not compiled, then we resort to current
  49  * behaviour, which is cpu_possible == cpu_present.
  50  * - Ashok Raj
  51  *
  52  * Three ways to find out the number of additional hotplug CPUs:
  53  * - If the BIOS specified disabled CPUs in ACPI/mptables use that.
  54  * - The user can overwrite it with additional_cpus=NUM
  55  * - Otherwise don't reserve additional CPUs.
  56  * We do this because additional CPUs waste a lot of memory.
  57  * -AK
  58  */
  59 __init void prefill_possible_map(void)
  60 {
  61         int i;
  62         int possible;
  63
  64         if (additional_cpus == -1) {
  65                 if (disabled_cpus > 0)
  66                         additional_cpus = disabled_cpus;
  67                 else
  68                         additional_cpus = 0;
  69         }
  70         possible = num_processors + additional_cpus;
  71         if (possible > NR_CPUS)
  72                 possible = NR_CPUS;
  73
  74         printk(KERN_INFO "SMP: Allowing %d CPUs, %d hotplug CPUs\n",
  75                 possible, max_t(int, possible - num_processors, 0));
  76
  77         for (i = 0; i < possible; i++)
  78                 cpu_set(i, cpu_possible_map);
  79 }
  80 #endif
  81