Merge branch 'x86-pti-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git...
[linux-2.6-block.git] / arch / x86 / kernel / setup_percpu.c
CommitLineData
b2441318 1// SPDX-License-Identifier: GPL-2.0
40685236
JP
2#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
3
4fe29a85 4#include <linux/kernel.h>
523d0fb4 5#include <linux/export.h>
4fe29a85 6#include <linux/init.h>
2013288f 7#include <linux/memblock.h>
4fe29a85 8#include <linux/percpu.h>
1ecd2765 9#include <linux/kexec.h>
17b4cceb 10#include <linux/crash_dump.h>
8a87dd9a
JSR
11#include <linux/smp.h>
12#include <linux/topology.h>
5f5d8405 13#include <linux/pfn.h>
4fe29a85
GOC
14#include <asm/sections.h>
15#include <asm/processor.h>
523d0fb4 16#include <asm/desc.h>
4fe29a85 17#include <asm/setup.h>
0fc0906e 18#include <asm/mpspec.h>
76eb4131 19#include <asm/apicdef.h>
1ecd2765 20#include <asm/highmem.h>
1a51e3a0 21#include <asm/proto.h>
06879033 22#include <asm/cpumask.h>
34019be1 23#include <asm/cpu.h>
60a5317f 24#include <asm/stackprotector.h>
76eb4131 25
0816b0f0 26DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number);
ea927906 27EXPORT_PER_CPU_SYMBOL(cpu_number);
ea927906 28
1688401a
BG
29#ifdef CONFIG_X86_64
30#define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
31#else
32#define BOOT_PERCPU_OFFSET 0
33#endif
34
2c773dd3 35DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
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BG
36EXPORT_PER_CPU_SYMBOL(this_cpu_off);
37
404f6aac 38unsigned long __per_cpu_offset[NR_CPUS] __ro_after_init = {
34019be1 39 [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
9939ddaf 40};
9939ddaf 41EXPORT_SYMBOL(__per_cpu_offset);
4fe29a85 42
6b19b0c2
TH
43/*
44 * On x86_64 symbols referenced from code should be reachable using
45 * 32bit relocations. Reserve space for static percpu variables in
46 * modules so that they are always served from the first chunk which
47 * is located at the percpu segment base. On x86_32, anything can
48 * address anywhere. No need to reserve space in the first chunk.
49 */
50#ifdef CONFIG_X86_64
51#define PERCPU_FIRST_CHUNK_RESERVE PERCPU_MODULE_RESERVE
52#else
53#define PERCPU_FIRST_CHUNK_RESERVE 0
54#endif
55
4518e6a0 56#ifdef CONFIG_X86_32
89c92151
TH
57/**
58 * pcpu_need_numa - determine percpu allocation needs to consider NUMA
59 *
60 * If NUMA is not configured or there is only one NUMA node available,
61 * there is no reason to consider NUMA. This function determines
62 * whether percpu allocation should consider NUMA or not.
63 *
64 * RETURNS:
65 * true if NUMA should be considered; otherwise, false.
66 */
67static bool __init pcpu_need_numa(void)
68{
69#ifdef CONFIG_NEED_MULTIPLE_NODES
70 pg_data_t *last = NULL;
71 unsigned int cpu;
72
73 for_each_possible_cpu(cpu) {
74 int node = early_cpu_to_node(cpu);
75
76 if (node_online(node) && NODE_DATA(node) &&
77 last && last != NODE_DATA(node))
78 return true;
79
80 last = NODE_DATA(node);
81 }
82#endif
83 return false;
84}
4518e6a0 85#endif
89c92151 86
5f5d8405
TH
87/**
88 * pcpu_alloc_bootmem - NUMA friendly alloc_bootmem wrapper for percpu
89 * @cpu: cpu to allocate for
90 * @size: size allocation in bytes
91 * @align: alignment
92 *
93 * Allocate @size bytes aligned at @align for cpu @cpu. This wrapper
94 * does the right thing for NUMA regardless of the current
95 * configuration.
96 *
97 * RETURNS:
98 * Pointer to the allocated area on success, NULL on failure.
99 */
100static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size,
101 unsigned long align)
102{
103 const unsigned long goal = __pa(MAX_DMA_ADDRESS);
104#ifdef CONFIG_NEED_MULTIPLE_NODES
105 int node = early_cpu_to_node(cpu);
106 void *ptr;
107
108 if (!node_online(node) || !NODE_DATA(node)) {
26fb3dae 109 ptr = memblock_alloc_from(size, align, goal);
5f5d8405
TH
110 pr_info("cpu %d has no node %d or node-local memory\n",
111 cpu, node);
112 pr_debug("per cpu data for cpu%d %lu bytes at %016lx\n",
113 cpu, size, __pa(ptr));
114 } else {
26fb3dae
MR
115 ptr = memblock_alloc_try_nid(size, align, goal,
116 MEMBLOCK_ALLOC_ACCESSIBLE,
117 node);
bf2886ef 118
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JP
119 pr_debug("per cpu data for cpu%d %lu bytes on node%d at %016lx\n",
120 cpu, size, node, __pa(ptr));
5f5d8405
TH
121 }
122 return ptr;
123#else
26fb3dae 124 return memblock_alloc_from(size, align, goal);
5f5d8405
TH
125#endif
126}
127
d4b95f80
TH
128/*
129 * Helpers for first chunk memory allocation
130 */
3cbc8565 131static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
d4b95f80 132{
3cbc8565 133 return pcpu_alloc_bootmem(cpu, size, align);
d4b95f80
TH
134}
135
136static void __init pcpu_fc_free(void *ptr, size_t size)
137{
2013288f 138 memblock_free(__pa(ptr), size);
d4b95f80
TH
139}
140
4518e6a0 141static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
a530b795 142{
4518e6a0 143#ifdef CONFIG_NEED_MULTIPLE_NODES
a530b795
TH
144 if (early_cpu_to_node(from) == early_cpu_to_node(to))
145 return LOCAL_DISTANCE;
146 else
147 return REMOTE_DISTANCE;
8ac83757 148#else
4518e6a0 149 return LOCAL_DISTANCE;
8ac83757 150#endif
89c92151
TH
151}
152
00ae4064 153static void __init pcpup_populate_pte(unsigned long addr)
458a3e64
TH
154{
155 populate_extra_pte(addr);
156}
157
b2d2f431
BG
158static inline void setup_percpu_segment(int cpu)
159{
160#ifdef CONFIG_X86_32
1dd439fe
TG
161 struct desc_struct d = GDT_ENTRY_INIT(0x8092, per_cpu_offset(cpu),
162 0xFFFFF);
b2d2f431 163
1dd439fe 164 write_gdt_entry(get_cpu_gdt_rw(cpu), GDT_ENTRY_PERCPU, &d, DESCTYPE_S);
b2d2f431
BG
165#endif
166}
167
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GOC
168void __init setup_per_cpu_areas(void)
169{
5f5d8405 170 unsigned int cpu;
11124411 171 unsigned long delta;
fb435d52 172 int rc;
a1681965 173
b9726c26 174 pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%u nr_node_ids:%u\n",
a1681965 175 NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
11124411 176
8ac83757 177 /*
4518e6a0
TH
178 * Allocate percpu area. Embedding allocator is our favorite;
179 * however, on NUMA configurations, it can result in very
180 * sparse unit mapping and vmalloc area isn't spacious enough
181 * on 32bit. Use page in that case.
8ac83757 182 */
4518e6a0
TH
183#ifdef CONFIG_X86_32
184 if (pcpu_chosen_fc == PCPU_FC_AUTO && pcpu_need_numa())
185 pcpu_chosen_fc = PCPU_FC_PAGE;
186#endif
fb435d52 187 rc = -EINVAL;
4518e6a0 188 if (pcpu_chosen_fc != PCPU_FC_PAGE) {
4518e6a0
TH
189 const size_t dyn_size = PERCPU_MODULE_RESERVE +
190 PERCPU_DYNAMIC_RESERVE - PERCPU_FIRST_CHUNK_RESERVE;
d5e28005
TH
191 size_t atom_size;
192
193 /*
194 * On 64bit, use PMD_SIZE for atom_size so that embedded
195 * percpu areas are aligned to PMD. This, in the future,
196 * can also allow using PMD mappings in vmalloc area. Use
197 * PAGE_SIZE on 32bit as vmalloc space is highly contended
198 * and large vmalloc area allocs can easily fail.
199 */
200#ifdef CONFIG_X86_64
201 atom_size = PMD_SIZE;
202#else
203 atom_size = PAGE_SIZE;
204#endif
4518e6a0
TH
205 rc = pcpu_embed_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
206 dyn_size, atom_size,
207 pcpu_cpu_distance,
208 pcpu_fc_alloc, pcpu_fc_free);
fb435d52 209 if (rc < 0)
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KW
210 pr_warn("%s allocator failed (%d), falling back to page size\n",
211 pcpu_fc_names[pcpu_chosen_fc], rc);
fa8a7094 212 }
fb435d52 213 if (rc < 0)
4518e6a0
TH
214 rc = pcpu_page_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
215 pcpu_fc_alloc, pcpu_fc_free,
216 pcpup_populate_pte);
fb435d52
TH
217 if (rc < 0)
218 panic("cannot initialize percpu area (err=%d)", rc);
11124411 219
5f5d8405 220 /* alrighty, percpu areas up and running */
11124411
TH
221 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
222 for_each_possible_cpu(cpu) {
fb435d52 223 per_cpu_offset(cpu) = delta + pcpu_unit_offsets[cpu];
26f80bd6 224 per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
ea927906 225 per_cpu(cpu_number, cpu) = cpu;
b2d2f431 226 setup_percpu_segment(cpu);
60a5317f 227 setup_stack_canary_segment(cpu);
0d77e7f0 228 /*
cf3997f5
TH
229 * Copy data used in early init routines from the
230 * initial arrays to the per cpu data areas. These
231 * arrays then become expendable and the *_early_ptr's
232 * are zeroed indicating that the static arrays are
233 * gone.
0d77e7f0 234 */
ec70de8b 235#ifdef CONFIG_X86_LOCAL_APIC
0d77e7f0 236 per_cpu(x86_cpu_to_apicid, cpu) =
cf3997f5 237 early_per_cpu_map(x86_cpu_to_apicid, cpu);
0d77e7f0 238 per_cpu(x86_bios_cpu_apicid, cpu) =
cf3997f5 239 early_per_cpu_map(x86_bios_cpu_apicid, cpu);
3e9e57fa
VK
240 per_cpu(x86_cpu_to_acpiid, cpu) =
241 early_per_cpu_map(x86_cpu_to_acpiid, cpu);
ec70de8b 242#endif
4c321ff8
TH
243#ifdef CONFIG_X86_32
244 per_cpu(x86_cpu_to_logical_apicid, cpu) =
245 early_per_cpu_map(x86_cpu_to_logical_apicid, cpu);
246#endif
6470aff6
BG
247#ifdef CONFIG_NUMA
248 per_cpu(x86_cpu_to_node_map, cpu) =
cf3997f5 249 early_per_cpu_map(x86_cpu_to_node_map, cpu);
9aebbdb6 250 /*
a4ce96ac 251 * Ensure that the boot cpu numa_node is correct when the boot
9aebbdb6
YL
252 * cpu is on a node that doesn't have memory installed.
253 * Also cpu_up() will call cpu_to_node() for APs when
254 * MEMORY_HOTPLUG is defined, before per_cpu(numa_node) is set
255 * up later with c_init aka intel_init/amd_init.
256 * So set them all (boot cpu and all APs).
257 */
258 set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
6470aff6 259#endif
1a51e3a0 260 /*
c273fb3b 261 * Up to this point, the boot CPU has been using .init.data
2697fbd5 262 * area. Reload any changed state for the boot CPU.
1a51e3a0 263 */
f6e9456c 264 if (!cpu)
552be871 265 switch_to_new_gdt(cpu);
4fe29a85
GOC
266 }
267
0d77e7f0 268 /* indicate the early static arrays will soon be gone */
22f25138 269#ifdef CONFIG_X86_LOCAL_APIC
0d77e7f0
BG
270 early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
271 early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
3e9e57fa 272 early_per_cpu_ptr(x86_cpu_to_acpiid) = NULL;
22f25138 273#endif
4c321ff8
TH
274#ifdef CONFIG_X86_32
275 early_per_cpu_ptr(x86_cpu_to_logical_apicid) = NULL;
276#endif
645a7919 277#ifdef CONFIG_NUMA
0d77e7f0
BG
278 early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
279#endif
9f0e8d04 280
9f248bde
MT
281 /* Setup node to cpumask map */
282 setup_node_to_cpumask_map();
c2d1cec1
MT
283
284 /* Setup cpu initialized, callin, callout masks */
285 setup_cpu_local_masks();
23b2a4dd 286
23b2a4dd 287 /*
d2b6dc61
AL
288 * Sync back kernel address range again. We already did this in
289 * setup_arch(), but percpu data also needs to be available in
290 * the smpboot asm. We can't reliably pick up percpu mappings
291 * using vmalloc_fault(), because exception dispatch needs
292 * percpu data.
945fd17a
TG
293 *
294 * FIXME: Can the later sync in setup_cpu_entry_areas() replace
295 * this call?
23b2a4dd 296 */
945fd17a 297 sync_initial_page_table();
4fe29a85 298}