arch/x86/kernel/setup.c

   1 #include <linux/kernel.h>
   2 #include <linux/module.h>
   3 #include <linux/init.h>
   4 #include <linux/bootmem.h>
   5 #include <linux/percpu.h>
   6 #include <asm/smp.h>
   7 #include <asm/percpu.h>
   8 #include <asm/sections.h>
   9 #include <asm/processor.h>
  10 #include <asm/setup.h>
  11 #include <asm/topology.h>
  12 #include <asm/mpspec.h>
  13 #include <asm/apicdef.h>
  14
  15 unsigned int num_processors;
  16 unsigned disabled_cpus __cpuinitdata;
  17 /* Processor that is doing the boot up */
  18 unsigned int boot_cpu_physical_apicid = -1U;
  19 EXPORT_SYMBOL(boot_cpu_physical_apicid);
  20
  21 DEFINE_PER_CPU(u16, x86_cpu_to_apicid) = BAD_APICID;
  22 EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid);
  23
  24 /* Bitmask of physically existing CPUs */
  25 physid_mask_t phys_cpu_present_map;
  26
  27 #if defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) && defined(CONFIG_SMP)
  28 /*
  29  * Copy data used in early init routines from the initial arrays to the
  30  * per cpu data areas.  These arrays then become expendable and the
  31  * *_early_ptr's are zeroed indicating that the static arrays are gone.
  32  */
  33 static void __init setup_per_cpu_maps(void)
  34 {
  35         int cpu;
  36
  37         for_each_possible_cpu(cpu) {
  38                 per_cpu(x86_cpu_to_apicid, cpu) = x86_cpu_to_apicid_init[cpu];
  39                 per_cpu(x86_bios_cpu_apicid, cpu) =
  40                                                 x86_bios_cpu_apicid_init[cpu];
  41 #ifdef CONFIG_NUMA
  42                 per_cpu(x86_cpu_to_node_map, cpu) =
  43                                                 x86_cpu_to_node_map_init[cpu];
  44 #endif
  45         }
  46
  47         /* indicate the early static arrays will soon be gone */
  48         x86_cpu_to_apicid_early_ptr = NULL;
  49         x86_bios_cpu_apicid_early_ptr = NULL;
  50 #ifdef CONFIG_NUMA
  51         x86_cpu_to_node_map_early_ptr = NULL;
  52 #endif
  53 }
  54
  55 #ifdef CONFIG_HAVE_CPUMASK_OF_CPU_MAP
  56 cpumask_t *cpumask_of_cpu_map __read_mostly;
  57 EXPORT_SYMBOL(cpumask_of_cpu_map);
  58
  59 /* requires nr_cpu_ids to be initialized */
  60 static void __init setup_cpumask_of_cpu(void)
  61 {
  62         int i;
  63
  64         /* alloc_bootmem zeroes memory */
  65         cpumask_of_cpu_map = alloc_bootmem_low(sizeof(cpumask_t) * nr_cpu_ids);
  66         for (i = 0; i < nr_cpu_ids; i++)
  67                 cpu_set(i, cpumask_of_cpu_map[i]);
  68 }
  69 #else
  70 static inline void setup_cpumask_of_cpu(void) { }
  71 #endif
  72
  73 #ifdef CONFIG_X86_32
  74 /*
  75  * Great future not-so-futuristic plan: make i386 and x86_64 do it
  76  * the same way
  77  */
  78 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
  79 EXPORT_SYMBOL(__per_cpu_offset);
  80 #endif
  81
  82 /*
  83  * Great future plan:
  84  * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
  85  * Always point %gs to its beginning
  86  */
  87 void __init setup_per_cpu_areas(void)
  88 {
  89         int i, highest_cpu = 0;
  90         unsigned long size;
  91
  92 #ifdef CONFIG_HOTPLUG_CPU
  93         prefill_possible_map();
  94 #endif
  95
  96         /* Copy section for each CPU (we discard the original) */
  97         size = PERCPU_ENOUGH_ROOM;
  98         printk(KERN_INFO "PERCPU: Allocating %zd bytes of per cpu data\n",
  99                           size);
 100
 101         for_each_possible_cpu(i) {
 102                 char *ptr;
 103 #ifndef CONFIG_NEED_MULTIPLE_NODES
 104                 ptr = alloc_bootmem_pages(size);
 105 #else
 106                 int node = early_cpu_to_node(i);
 107                 if (!node_online(node) || !NODE_DATA(node)) {
 108                         ptr = alloc_bootmem_pages(size);
 109                         printk(KERN_INFO
 110                                "cpu %d has no node or node-local memory\n", i);
 111                 }
 112                 else
 113                         ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
 114 #endif
 115                 if (!ptr)
 116                         panic("Cannot allocate cpu data for CPU %d\n", i);
 117 #ifdef CONFIG_X86_64
 118                 cpu_pda(i)->data_offset = ptr - __per_cpu_start;
 119 #else
 120                 __per_cpu_offset[i] = ptr - __per_cpu_start;
 121 #endif
 122                 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
 123
 124                 highest_cpu = i;
 125         }
 126
 127         nr_cpu_ids = highest_cpu + 1;
 128         printk(KERN_DEBUG "NR_CPUS: %d, nr_cpu_ids: %d\n", NR_CPUS, nr_cpu_ids);
 129
 130         /* Setup percpu data maps */
 131         setup_per_cpu_maps();
 132
 133         /* Setup cpumask_of_cpu map */
 134         setup_cpumask_of_cpu();
 135 }
 136
 137 #endif