1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
|
// SPDX-License-Identifier: GPL-2.0
#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
#include <linux/kernel.h>
#include <linux/export.h>
#include <linux/init.h>
#include <linux/memblock.h>
#include <linux/percpu.h>
#include <linux/kexec.h>
#include <linux/crash_dump.h>
#include <linux/smp.h>
#include <linux/topology.h>
#include <linux/pfn.h>
#include <linux/stackprotector.h>
#include <asm/sections.h>
#include <asm/processor.h>
#include <asm/desc.h>
#include <asm/setup.h>
#include <asm/mpspec.h>
#include <asm/apicdef.h>
#include <asm/highmem.h>
#include <asm/proto.h>
#include <asm/cpumask.h>
#include <asm/cpu.h>
DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number);
EXPORT_PER_CPU_SYMBOL(cpu_number);
#ifdef CONFIG_X86_64
#define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
#else
#define BOOT_PERCPU_OFFSET 0
#endif
DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
EXPORT_PER_CPU_SYMBOL(this_cpu_off);
unsigned long __per_cpu_offset[NR_CPUS] __ro_after_init = {
[0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
};
EXPORT_SYMBOL(__per_cpu_offset);
/*
* On x86_64 symbols referenced from code should be reachable using
* 32bit relocations. Reserve space for static percpu variables in
* modules so that they are always served from the first chunk which
* is located at the percpu segment base. On x86_32, anything can
* address anywhere. No need to reserve space in the first chunk.
*/
#ifdef CONFIG_X86_64
#define PERCPU_FIRST_CHUNK_RESERVE PERCPU_MODULE_RESERVE
#else
#define PERCPU_FIRST_CHUNK_RESERVE 0
#endif
#ifdef CONFIG_X86_32
/**
* pcpu_need_numa - determine percpu allocation needs to consider NUMA
*
* If NUMA is not configured or there is only one NUMA node available,
* there is no reason to consider NUMA. This function determines
* whether percpu allocation should consider NUMA or not.
*
* RETURNS:
* true if NUMA should be considered; otherwise, false.
*/
static bool __init pcpu_need_numa(void)
{
#ifdef CONFIG_NUMA
pg_data_t *last = NULL;
unsigned int cpu;
for_each_possible_cpu(cpu) {
int node = early_cpu_to_node(cpu);
if (node_online(node) && NODE_DATA(node) &&
last && last != NODE_DATA(node))
return true;
last = NODE_DATA(node);
}
#endif
return false;
}
#endif
static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
{
#ifdef CONFIG_NUMA
if (early_cpu_to_node(from) == early_cpu_to_node(to))
return LOCAL_DISTANCE;
else
return REMOTE_DISTANCE;
#else
return LOCAL_DISTANCE;
#endif
}
static int __init pcpu_cpu_to_node(int cpu)
{
return early_cpu_to_node(cpu);
}
void __init pcpu_populate_pte(unsigned long addr)
{
populate_extra_pte(addr);
}
static inline void setup_percpu_segment(int cpu)
{
#ifdef CONFIG_X86_32
struct desc_struct d = GDT_ENTRY_INIT(0x8092, per_cpu_offset(cpu),
0xFFFFF);
write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_PERCPU, &d, DESCTYPE_S);
#endif
}
void __init setup_per_cpu_areas(void)
{
unsigned int cpu;
unsigned long delta;
int rc;
pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%u nr_node_ids:%u\n",
NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
/*
* Allocate percpu area. Embedding allocator is our favorite;
* however, on NUMA configurations, it can result in very
* sparse unit mapping and vmalloc area isn't spacious enough
* on 32bit. Use page in that case.
*/
#ifdef CONFIG_X86_32
if (pcpu_chosen_fc == PCPU_FC_AUTO && pcpu_need_numa())
pcpu_chosen_fc = PCPU_FC_PAGE;
#endif
rc = -EINVAL;
if (pcpu_chosen_fc != PCPU_FC_PAGE) {
const size_t dyn_size = PERCPU_MODULE_RESERVE +
PERCPU_DYNAMIC_RESERVE - PERCPU_FIRST_CHUNK_RESERVE;
size_t atom_size;
/*
* On 64bit, use PMD_SIZE for atom_size so that embedded
* percpu areas are aligned to PMD. This, in the future,
* can also allow using PMD mappings in vmalloc area. Use
* PAGE_SIZE on 32bit as vmalloc space is highly contended
* and large vmalloc area allocs can easily fail.
*/
#ifdef CONFIG_X86_64
atom_size = PMD_SIZE;
#else
atom_size = PAGE_SIZE;
#endif
rc = pcpu_embed_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
dyn_size, atom_size,
pcpu_cpu_distance,
pcpu_cpu_to_node);
if (rc < 0)
pr_warn("%s allocator failed (%d), falling back to page size\n",
pcpu_fc_names[pcpu_chosen_fc], rc);
}
if (rc < 0)
rc = pcpu_page_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
pcpu_cpu_to_node);
if (rc < 0)
panic("cannot initialize percpu area (err=%d)", rc);
/* alrighty, percpu areas up and running */
delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
for_each_possible_cpu(cpu) {
per_cpu_offset(cpu) = delta + pcpu_unit_offsets[cpu];
per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
per_cpu(cpu_number, cpu) = cpu;
setup_percpu_segment(cpu);
/*
* Copy data used in early init routines from the
* initial arrays to the per cpu data areas. These
* arrays then become expendable and the *_early_ptr's
* are zeroed indicating that the static arrays are
* gone.
*/
#ifdef CONFIG_X86_LOCAL_APIC
per_cpu(x86_cpu_to_apicid, cpu) =
early_per_cpu_map(x86_cpu_to_apicid, cpu);
per_cpu(x86_bios_cpu_apicid, cpu) =
early_per_cpu_map(x86_bios_cpu_apicid, cpu);
per_cpu(x86_cpu_to_acpiid, cpu) =
early_per_cpu_map(x86_cpu_to_acpiid, cpu);
#endif
#ifdef CONFIG_X86_32
per_cpu(x86_cpu_to_logical_apicid, cpu) =
early_per_cpu_map(x86_cpu_to_logical_apicid, cpu);
#endif
#ifdef CONFIG_NUMA
per_cpu(x86_cpu_to_node_map, cpu) =
early_per_cpu_map(x86_cpu_to_node_map, cpu);
/*
* Ensure that the boot cpu numa_node is correct when the boot
* cpu is on a node that doesn't have memory installed.
* Also cpu_up() will call cpu_to_node() for APs when
* MEMORY_HOTPLUG is defined, before per_cpu(numa_node) is set
* up later with c_init aka intel_init/amd_init.
* So set them all (boot cpu and all APs).
*/
set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
#endif
/*
* Up to this point, the boot CPU has been using .init.data
* area. Reload any changed state for the boot CPU.
*/
if (!cpu)
switch_to_new_gdt(cpu);
}
/* indicate the early static arrays will soon be gone */
#ifdef CONFIG_X86_LOCAL_APIC
early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
early_per_cpu_ptr(x86_cpu_to_acpiid) = NULL;
#endif
#ifdef CONFIG_X86_32
early_per_cpu_ptr(x86_cpu_to_logical_apicid) = NULL;
#endif
#ifdef CONFIG_NUMA
early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
#endif
/* Setup node to cpumask map */
setup_node_to_cpumask_map();
/* Setup cpu initialized, callin, callout masks */
setup_cpu_local_masks();
/*
* Sync back kernel address range again. We already did this in
* setup_arch(), but percpu data also needs to be available in
* the smpboot asm and arch_sync_kernel_mappings() doesn't sync to
* swapper_pg_dir on 32-bit. The per-cpu mappings need to be available
* there too.
*
* FIXME: Can the later sync in setup_cpu_entry_areas() replace
* this call?
*/
sync_initial_page_table();
}
|
