arch/x86/kernel/setup_percpu.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 <linux/kexec.h>
   7 #include <linux/crash_dump.h>
   8 #include <linux/smp.h>
   9 #include <linux/topology.h>
  10 #include <asm/sections.h>
  11 #include <asm/processor.h>
  12 #include <asm/setup.h>
  13 #include <asm/mpspec.h>
  14 #include <asm/apicdef.h>
  15 #include <asm/highmem.h>
  16 #include <asm/proto.h>
  17 #include <asm/cpumask.h>
  18
  19 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
  20 # define DBG(x...) printk(KERN_DEBUG x)
  21 #else
  22 # define DBG(x...)
  23 #endif
  24
  25 DEFINE_PER_CPU(int, cpu_number);
  26 EXPORT_PER_CPU_SYMBOL(cpu_number);
  27
  28 #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
  29
  30 #ifdef CONFIG_X86_64
  31 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
  32         [0] = (unsigned long)__per_cpu_load,
  33 };
  34 #else
  35 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
  36 #endif
  37 EXPORT_SYMBOL(__per_cpu_offset);
  38
  39 /*
  40  * Great future plan:
  41  * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
  42  * Always point %gs to its beginning
  43  */
  44 void __init setup_per_cpu_areas(void)
  45 {
  46         ssize_t size;
  47         char *ptr;
  48         int cpu;
  49
  50         /* Copy section for each CPU (we discard the original) */
  51         size = roundup(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
  52
  53         pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n",
  54                 NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
  55
  56         pr_info("PERCPU: Allocating %zd bytes of per cpu data\n", size);
  57
  58         for_each_possible_cpu(cpu) {
  59 #ifndef CONFIG_NEED_MULTIPLE_NODES
  60                 ptr = alloc_bootmem_pages(size);
  61 #else
  62                 int node = early_cpu_to_node(cpu);
  63                 if (!node_online(node) || !NODE_DATA(node)) {
  64                         ptr = alloc_bootmem_pages(size);
  65                         pr_info("cpu %d has no node %d or node-local memory\n",
  66                                 cpu, node);
  67                         pr_debug("per cpu data for cpu%d at %016lx\n",
  68                                  cpu, __pa(ptr));
  69                 } else {
  70                         ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
  71                         pr_debug("per cpu data for cpu%d on node%d at %016lx\n",
  72                                 cpu, node, __pa(ptr));
  73                 }
  74 #endif
  75
  76                 memcpy(ptr, __per_cpu_load, __per_cpu_end - __per_cpu_start);
  77                 per_cpu_offset(cpu) = ptr - __per_cpu_start;
  78                 per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
  79                 per_cpu(cpu_number, cpu) = cpu;
  80                 /*
  81                  * Copy data used in early init routines from the initial arrays to the
  82                  * per cpu data areas.  These arrays then become expendable and the
  83                  * *_early_ptr's are zeroed indicating that the static arrays are gone.
  84                  */
  85 #ifdef CONFIG_X86_LOCAL_APIC
  86                 per_cpu(x86_cpu_to_apicid, cpu) =
  87                                 early_per_cpu_map(x86_cpu_to_apicid, cpu);
  88                 per_cpu(x86_bios_cpu_apicid, cpu) =
  89                                 early_per_cpu_map(x86_bios_cpu_apicid, cpu);
  90 #endif
  91 #ifdef CONFIG_X86_64
  92                 per_cpu(irq_stack_ptr, cpu) =
  93                         per_cpu(irq_stack_union.irq_stack, cpu) + IRQ_STACK_SIZE - 64;
  94 #ifdef CONFIG_NUMA
  95                 per_cpu(x86_cpu_to_node_map, cpu) =
  96                                 early_per_cpu_map(x86_cpu_to_node_map, cpu);
  97 #endif
  98                 /*
  99                  * Up to this point, CPU0 has been using .data.init
 100                  * area.  Reload %gs offset for CPU0.
 101                  */
 102                 if (cpu == 0)
 103                         load_gs_base(cpu);
 104 #endif
 105
 106                 DBG("PERCPU: cpu %4d %p\n", cpu, ptr);
 107         }
 108
 109         /* indicate the early static arrays will soon be gone */
 110         early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
 111         early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
 112 #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
 113         early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
 114 #endif
 115
 116         /* Setup node to cpumask map */
 117         setup_node_to_cpumask_map();
 118
 119         /* Setup cpu initialized, callin, callout masks */
 120         setup_cpu_local_masks();
 121 }
 122
 123 #endif
 124