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 /*
  26  * Could be inside CONFIG_HAVE_SETUP_PER_CPU_AREA with other stuff but
  27  * voyager wants cpu_number too.
  28  */
  29 #ifdef CONFIG_SMP
  30 DEFINE_PER_CPU(int, cpu_number);
  31 EXPORT_PER_CPU_SYMBOL(cpu_number);
  32 #endif
  33
  34 #ifdef CONFIG_X86_LOCAL_APIC
  35 unsigned int num_processors;
  36 unsigned disabled_cpus __cpuinitdata;
  37 /* Processor that is doing the boot up */
  38 unsigned int boot_cpu_physical_apicid = -1U;
  39 EXPORT_SYMBOL(boot_cpu_physical_apicid);
  40 unsigned int max_physical_apicid;
  41
  42 /* Bitmask of physically existing CPUs */
  43 physid_mask_t phys_cpu_present_map;
  44 #endif
  45
  46 /*
  47  * Map cpu index to physical APIC ID
  48  */
  49 DEFINE_EARLY_PER_CPU(u16, x86_cpu_to_apicid, BAD_APICID);
  50 DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
  51 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
  52 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
  53
  54 #ifdef CONFIG_HAVE_SETUP_PER_CPU_AREA
  55
  56 #ifdef CONFIG_X86_64
  57 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
  58         [0] = (unsigned long)__per_cpu_load,
  59 };
  60 #else
  61 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
  62 #endif
  63 EXPORT_SYMBOL(__per_cpu_offset);
  64
  65 /*
  66  * Great future plan:
  67  * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
  68  * Always point %gs to its beginning
  69  */
  70 void __init setup_per_cpu_areas(void)
  71 {
  72         ssize_t size;
  73         char *ptr;
  74         int cpu;
  75
  76         /* Copy section for each CPU (we discard the original) */
  77         size = roundup(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
  78
  79         pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n",
  80                 NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
  81
  82         pr_info("PERCPU: Allocating %zd bytes of per cpu data\n", size);
  83
  84         for_each_possible_cpu(cpu) {
  85 #ifndef CONFIG_NEED_MULTIPLE_NODES
  86                 ptr = alloc_bootmem_pages(size);
  87 #else
  88                 int node = early_cpu_to_node(cpu);
  89                 if (!node_online(node) || !NODE_DATA(node)) {
  90                         ptr = alloc_bootmem_pages(size);
  91                         pr_info("cpu %d has no node %d or node-local memory\n",
  92                                 cpu, node);
  93                         pr_debug("per cpu data for cpu%d at %016lx\n",
  94                                  cpu, __pa(ptr));
  95                 } else {
  96                         ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
  97                         pr_debug("per cpu data for cpu%d on node%d at %016lx\n",
  98                                 cpu, node, __pa(ptr));
  99                 }
 100 #endif
 101
 102                 memcpy(ptr, __per_cpu_load, __per_cpu_end - __per_cpu_start);
 103                 per_cpu_offset(cpu) = ptr - __per_cpu_start;
 104                 per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
 105                 per_cpu(cpu_number, cpu) = cpu;
 106                 /*
 107                  * Copy data used in early init routines from the initial arrays to the
 108                  * per cpu data areas.  These arrays then become expendable and the
 109                  * *_early_ptr's are zeroed indicating that the static arrays are gone.
 110                  */
 111                 per_cpu(x86_cpu_to_apicid, cpu) =
 112                                 early_per_cpu_map(x86_cpu_to_apicid, cpu);
 113                 per_cpu(x86_bios_cpu_apicid, cpu) =
 114                                 early_per_cpu_map(x86_bios_cpu_apicid, cpu);
 115 #ifdef CONFIG_X86_64
 116                 per_cpu(irq_stack_ptr, cpu) =
 117                         per_cpu(irq_stack_union.irq_stack, cpu) + IRQ_STACK_SIZE - 64;
 118 #ifdef CONFIG_NUMA
 119                 per_cpu(x86_cpu_to_node_map, cpu) =
 120                                 early_per_cpu_map(x86_cpu_to_node_map, cpu);
 121 #endif
 122                 /*
 123                  * Up to this point, CPU0 has been using .data.init
 124                  * area.  Reload %gs offset for CPU0.
 125                  */
 126                 if (cpu == 0)
 127                         load_gs_base(cpu);
 128 #endif
 129
 130                 DBG("PERCPU: cpu %4d %p\n", cpu, ptr);
 131         }
 132
 133         /* indicate the early static arrays will soon be gone */
 134         early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
 135         early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
 136 #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
 137         early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
 138 #endif
 139
 140         /* Setup node to cpumask map */
 141         setup_node_to_cpumask_map();
 142
 143         /* Setup cpu initialized, callin, callout masks */
 144         setup_cpu_local_masks();
 145 }
 146
 147 #endif
 148