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>
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>
20 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
21 # define DBG(x...) printk(KERN_DEBUG x)
26 DEFINE_PER_CPU(int, cpu_number);
27 EXPORT_PER_CPU_SYMBOL(cpu_number);
30 #define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
32 #define BOOT_PERCPU_OFFSET 0
35 DEFINE_PER_CPU(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
36 EXPORT_PER_CPU_SYMBOL(this_cpu_off);
38 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
39 [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
41 EXPORT_SYMBOL(__per_cpu_offset);
43 static inline void setup_percpu_segment(int cpu)
46 struct desc_struct gdt;
48 pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF,
49 0x2 | DESCTYPE_S, 0x8);
51 write_gdt_entry(get_cpu_gdt_table(cpu),
52 GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S);
58 * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
59 * Always point %gs to its beginning
61 void __init setup_per_cpu_areas(void)
67 /* Copy section for each CPU (we discard the original) */
68 size = roundup(PERCPU_ENOUGH_ROOM, PAGE_SIZE);
70 pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n",
71 NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
73 pr_info("PERCPU: Allocating %zd bytes of per cpu data\n", size);
75 for_each_possible_cpu(cpu) {
76 #ifndef CONFIG_NEED_MULTIPLE_NODES
77 ptr = alloc_bootmem_pages(size);
79 int node = early_cpu_to_node(cpu);
80 if (!node_online(node) || !NODE_DATA(node)) {
81 ptr = alloc_bootmem_pages(size);
82 pr_info("cpu %d has no node %d or node-local memory\n",
84 pr_debug("per cpu data for cpu%d at %016lx\n",
87 ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
88 pr_debug("per cpu data for cpu%d on node%d at %016lx\n",
89 cpu, node, __pa(ptr));
93 memcpy(ptr, __per_cpu_load, __per_cpu_end - __per_cpu_start);
94 per_cpu_offset(cpu) = ptr - __per_cpu_start;
95 per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
96 per_cpu(cpu_number, cpu) = cpu;
97 setup_percpu_segment(cpu);
99 * Copy data used in early init routines from the
100 * initial arrays to the per cpu data areas. These
101 * arrays then become expendable and the *_early_ptr's
102 * are zeroed indicating that the static arrays are
105 #ifdef CONFIG_X86_LOCAL_APIC
106 per_cpu(x86_cpu_to_apicid, cpu) =
107 early_per_cpu_map(x86_cpu_to_apicid, cpu);
108 per_cpu(x86_bios_cpu_apicid, cpu) =
109 early_per_cpu_map(x86_bios_cpu_apicid, cpu);
112 per_cpu(irq_stack_ptr, cpu) =
113 per_cpu(irq_stack_union.irq_stack, cpu) +
116 per_cpu(x86_cpu_to_node_map, cpu) =
117 early_per_cpu_map(x86_cpu_to_node_map, cpu);
121 * Up to this point, the boot CPU has been using .data.init
122 * area. Reload any changed state for the boot CPU.
124 if (cpu == boot_cpu_id)
125 switch_to_new_gdt(cpu);
127 DBG("PERCPU: cpu %4d %p\n", cpu, ptr);
130 /* indicate the early static arrays will soon be gone */
131 #ifdef CONFIG_X86_LOCAL_APIC
132 early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
133 early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
135 #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
136 early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
139 /* Setup node to cpumask map */
140 setup_node_to_cpumask_map();
142 /* Setup cpu initialized, callin, callout masks */
143 setup_cpu_local_masks();