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 #include <asm/cpu.h>
  19
  20 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
  21 # define DBG(x...) printk(KERN_DEBUG x)
  22 #else
  23 # define DBG(x...)
  24 #endif
  25
  26 DEFINE_PER_CPU(int, cpu_number);
  27 EXPORT_PER_CPU_SYMBOL(cpu_number);
  28
  29 #ifdef CONFIG_X86_64
  30 #define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
  31 #else
  32 #define BOOT_PERCPU_OFFSET 0
  33 #endif
  34
  35 DEFINE_PER_CPU(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
  36 EXPORT_PER_CPU_SYMBOL(this_cpu_off);
  37
  38 #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
  39
  40 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
  41         [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
  42 };
  43 EXPORT_SYMBOL(__per_cpu_offset);
  44
  45 /*
  46  * Great future plan:
  47  * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
  48  * Always point %gs to its beginning
  49  */
  50 void __init setup_per_cpu_areas(void)
  51 {
  52         ssize_t size;
  53         char *ptr;
  54         int cpu;
  55
  56         /* Copy section for each CPU (we discard the original) */
  57         size = roundup(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
  58
  59         pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n",
  60                 NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
  61
  62         pr_info("PERCPU: Allocating %zd bytes of per cpu data\n", size);
  63
  64         for_each_possible_cpu(cpu) {
  65 #ifndef CONFIG_NEED_MULTIPLE_NODES
  66                 ptr = alloc_bootmem_pages(size);
  67 #else
  68                 int node = early_cpu_to_node(cpu);
  69                 if (!node_online(node) || !NODE_DATA(node)) {
  70                         ptr = alloc_bootmem_pages(size);
  71                         pr_info("cpu %d has no node %d or node-local memory\n",
  72                                 cpu, node);
  73                         pr_debug("per cpu data for cpu%d at %016lx\n",
  74                                  cpu, __pa(ptr));
  75                 } else {
  76                         ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
  77                         pr_debug("per cpu data for cpu%d on node%d at %016lx\n",
  78                                 cpu, node, __pa(ptr));
  79                 }
  80 #endif
  81
  82                 memcpy(ptr, __per_cpu_load, __per_cpu_end - __per_cpu_start);
  83                 per_cpu_offset(cpu) = ptr - __per_cpu_start;
  84                 per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
  85                 per_cpu(cpu_number, cpu) = cpu;
  86                 /*
  87                  * Copy data used in early init routines from the initial arrays to the
  88                  * per cpu data areas.  These arrays then become expendable and the
  89                  * *_early_ptr's are zeroed indicating that the static arrays are gone.
  90                  */
  91 #ifdef CONFIG_X86_LOCAL_APIC
  92                 per_cpu(x86_cpu_to_apicid, cpu) =
  93                                 early_per_cpu_map(x86_cpu_to_apicid, cpu);
  94                 per_cpu(x86_bios_cpu_apicid, cpu) =
  95                                 early_per_cpu_map(x86_bios_cpu_apicid, cpu);
  96 #endif
  97 #ifdef CONFIG_X86_64
  98                 per_cpu(irq_stack_ptr, cpu) =
  99                         per_cpu(irq_stack_union.irq_stack, cpu) + IRQ_STACK_SIZE - 64;
 100 #ifdef CONFIG_NUMA
 101                 per_cpu(x86_cpu_to_node_map, cpu) =
 102                                 early_per_cpu_map(x86_cpu_to_node_map, cpu);
 103 #endif
 104                 /*
 105                  * Up to this point, the boot CPU has been using .data.init
 106                  * area.  Reload %gs offset for the boot CPU.
 107                  */
 108                 if (cpu == boot_cpu_id)
 109                         load_gs_base(cpu);
 110 #endif
 111
 112                 DBG("PERCPU: cpu %4d %p\n", cpu, ptr);
 113         }
 114
 115         /* indicate the early static arrays will soon be gone */
 116         early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
 117         early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
 118 #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
 119         early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
 120 #endif
 121
 122         /* Setup node to cpumask map */
 123         setup_node_to_cpumask_map();
 124
 125         /* Setup cpu initialized, callin, callout masks */
 126         setup_cpu_local_masks();
 127 }
 128
 129 #endif
 130