xref: /openbmc/linux/arch/x86/kernel/setup.c (revision f42b3800)
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 <asm/smp.h>
7 #include <asm/percpu.h>
8 #include <asm/sections.h>
9 #include <asm/processor.h>
10 #include <asm/setup.h>
11 #include <asm/topology.h>
12 #include <asm/mpspec.h>
13 #include <asm/apicdef.h>
14 
15 unsigned int num_processors;
16 unsigned disabled_cpus __cpuinitdata;
17 /* Processor that is doing the boot up */
18 unsigned int boot_cpu_physical_apicid = -1U;
19 EXPORT_SYMBOL(boot_cpu_physical_apicid);
20 
21 physid_mask_t phys_cpu_present_map;
22 
23 DEFINE_PER_CPU(u16, x86_cpu_to_apicid) = BAD_APICID;
24 EXPORT_PER_CPU_SYMBOL(x86_cpu_to_apicid);
25 
26 /* Bitmask of physically existing CPUs */
27 physid_mask_t phys_cpu_present_map;
28 
29 #if defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) && defined(CONFIG_SMP)
30 /*
31  * Copy data used in early init routines from the initial arrays to the
32  * per cpu data areas.  These arrays then become expendable and the
33  * *_early_ptr's are zeroed indicating that the static arrays are gone.
34  */
35 static void __init setup_per_cpu_maps(void)
36 {
37 	int cpu;
38 
39 	for_each_possible_cpu(cpu) {
40 		per_cpu(x86_cpu_to_apicid, cpu) = x86_cpu_to_apicid_init[cpu];
41 		per_cpu(x86_bios_cpu_apicid, cpu) =
42 						x86_bios_cpu_apicid_init[cpu];
43 #ifdef CONFIG_NUMA
44 		per_cpu(x86_cpu_to_node_map, cpu) =
45 						x86_cpu_to_node_map_init[cpu];
46 #endif
47 	}
48 
49 	/* indicate the early static arrays will soon be gone */
50 	x86_cpu_to_apicid_early_ptr = NULL;
51 	x86_bios_cpu_apicid_early_ptr = NULL;
52 #ifdef CONFIG_NUMA
53 	x86_cpu_to_node_map_early_ptr = NULL;
54 #endif
55 }
56 
57 #ifdef CONFIG_X86_32
58 /*
59  * Great future not-so-futuristic plan: make i386 and x86_64 do it
60  * the same way
61  */
62 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
63 EXPORT_SYMBOL(__per_cpu_offset);
64 #endif
65 
66 /*
67  * Great future plan:
68  * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
69  * Always point %gs to its beginning
70  */
71 void __init setup_per_cpu_areas(void)
72 {
73 	int i;
74 	unsigned long size;
75 
76 #ifdef CONFIG_HOTPLUG_CPU
77 	prefill_possible_map();
78 #endif
79 
80 	/* Copy section for each CPU (we discard the original) */
81 	size = PERCPU_ENOUGH_ROOM;
82 	printk(KERN_INFO "PERCPU: Allocating %lu bytes of per cpu data\n",
83 			  size);
84 
85 	for_each_possible_cpu(i) {
86 		char *ptr;
87 #ifndef CONFIG_NEED_MULTIPLE_NODES
88 		ptr = alloc_bootmem_pages(size);
89 #else
90 		int node = early_cpu_to_node(i);
91 		if (!node_online(node) || !NODE_DATA(node)) {
92 			ptr = alloc_bootmem_pages(size);
93 			printk(KERN_INFO
94 			       "cpu %d has no node or node-local memory\n", i);
95 		}
96 		else
97 			ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
98 #endif
99 		if (!ptr)
100 			panic("Cannot allocate cpu data for CPU %d\n", i);
101 #ifdef CONFIG_X86_64
102 		cpu_pda(i)->data_offset = ptr - __per_cpu_start;
103 #else
104 		__per_cpu_offset[i] = ptr - __per_cpu_start;
105 #endif
106 		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
107 	}
108 
109 	/* Setup percpu data maps */
110 	setup_per_cpu_maps();
111 }
112 
113 #endif
114