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>
19 #include <asm/stackprotector.h>
21 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
22 # define DBG(x...) printk(KERN_DEBUG x)
27 DEFINE_PER_CPU(int, cpu_number);
28 EXPORT_PER_CPU_SYMBOL(cpu_number);
31 #define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
33 #define BOOT_PERCPU_OFFSET 0
36 DEFINE_PER_CPU(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
37 EXPORT_PER_CPU_SYMBOL(this_cpu_off);
39 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
40 [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
42 EXPORT_SYMBOL(__per_cpu_offset);
44 static inline void setup_percpu_segment(int cpu)
47 struct desc_struct gdt;
49 pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF,
50 0x2 | DESCTYPE_S, 0x8);
52 write_gdt_entry(get_cpu_gdt_table(cpu),
53 GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S);
59 * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
60 * Always point %gs to its beginning
62 void __init setup_per_cpu_areas(void)
64 ssize_t size = __per_cpu_end - __per_cpu_start;
65 unsigned int nr_cpu_pages = DIV_ROUND_UP(size, PAGE_SIZE);
66 static struct page **pages;
68 unsigned int cpu, i, j;
70 size_t pcpu_unit_size;
72 pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n",
73 NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
74 pr_info("PERCPU: Allocating %zd bytes for static per cpu data\n", size);
76 pages_size = nr_cpu_pages * num_possible_cpus() * sizeof(pages[0]);
77 pages = alloc_bootmem(pages_size);
80 for_each_possible_cpu(cpu) {
83 for (i = 0; i < nr_cpu_pages; i++) {
84 #ifndef CONFIG_NEED_MULTIPLE_NODES
85 ptr = alloc_bootmem_pages(PAGE_SIZE);
87 int node = early_cpu_to_node(cpu);
89 if (!node_online(node) || !NODE_DATA(node)) {
90 ptr = alloc_bootmem_pages(PAGE_SIZE);
91 pr_info("cpu %d has no node %d or node-local "
92 "memory\n", cpu, node);
93 pr_debug("per cpu data for cpu%d at %016lx\n",
96 ptr = alloc_bootmem_pages_node(NODE_DATA(node),
98 pr_debug("per cpu data for cpu%d on node%d "
99 "at %016lx\n", cpu, node, __pa(ptr));
102 memcpy(ptr, __per_cpu_load + i * PAGE_SIZE, PAGE_SIZE);
103 pages[j++] = virt_to_page(ptr);
107 pcpu_unit_size = pcpu_setup_static(populate_extra_pte, pages, size);
109 free_bootmem(__pa(pages), pages_size);
111 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
112 for_each_possible_cpu(cpu) {
113 per_cpu_offset(cpu) = delta + cpu * pcpu_unit_size;
114 per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
115 per_cpu(cpu_number, cpu) = cpu;
116 setup_percpu_segment(cpu);
117 setup_stack_canary_segment(cpu);
119 * Copy data used in early init routines from the
120 * initial arrays to the per cpu data areas. These
121 * arrays then become expendable and the *_early_ptr's
122 * are zeroed indicating that the static arrays are
125 #ifdef CONFIG_X86_LOCAL_APIC
126 per_cpu(x86_cpu_to_apicid, cpu) =
127 early_per_cpu_map(x86_cpu_to_apicid, cpu);
128 per_cpu(x86_bios_cpu_apicid, cpu) =
129 early_per_cpu_map(x86_bios_cpu_apicid, cpu);
132 per_cpu(irq_stack_ptr, cpu) =
133 per_cpu(irq_stack_union.irq_stack, cpu) +
136 per_cpu(x86_cpu_to_node_map, cpu) =
137 early_per_cpu_map(x86_cpu_to_node_map, cpu);
141 * Up to this point, the boot CPU has been using .data.init
142 * area. Reload any changed state for the boot CPU.
144 if (cpu == boot_cpu_id)
145 switch_to_new_gdt(cpu);
147 DBG("PERCPU: cpu %4d %p\n", cpu, ptr);
150 /* indicate the early static arrays will soon be gone */
151 #ifdef CONFIG_X86_LOCAL_APIC
152 early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
153 early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
155 #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
156 early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
159 /* Setup node to cpumask map */
160 setup_node_to_cpumask_map();
162 /* Setup cpu initialized, callin, callout masks */
163 setup_cpu_local_masks();