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1#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
2
3#include <linux/kernel.h>
4#include <linux/module.h>
5#include <linux/init.h>
6#include <linux/bootmem.h>
7#include <linux/percpu.h>
8#include <linux/kexec.h>
9#include <linux/crash_dump.h>
10#include <linux/smp.h>
11#include <linux/topology.h>
12#include <linux/pfn.h>
13#include <asm/sections.h>
14#include <asm/processor.h>
15#include <asm/setup.h>
16#include <asm/mpspec.h>
17#include <asm/apicdef.h>
18#include <asm/highmem.h>
19#include <asm/proto.h>
20#include <asm/cpumask.h>
21#include <asm/cpu.h>
22#include <asm/stackprotector.h>
23
24DEFINE_PER_CPU(int, cpu_number);
25EXPORT_PER_CPU_SYMBOL(cpu_number);
26
27#ifdef CONFIG_X86_64
28#define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
29#else
30#define BOOT_PERCPU_OFFSET 0
31#endif
32
33DEFINE_PER_CPU(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
34EXPORT_PER_CPU_SYMBOL(this_cpu_off);
35
36unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
37 [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
38};
39EXPORT_SYMBOL(__per_cpu_offset);
40
41/*
42 * On x86_64 symbols referenced from code should be reachable using
43 * 32bit relocations. Reserve space for static percpu variables in
44 * modules so that they are always served from the first chunk which
45 * is located at the percpu segment base. On x86_32, anything can
46 * address anywhere. No need to reserve space in the first chunk.
47 */
48#ifdef CONFIG_X86_64
49#define PERCPU_FIRST_CHUNK_RESERVE PERCPU_MODULE_RESERVE
50#else
51#define PERCPU_FIRST_CHUNK_RESERVE 0
52#endif
53
54#ifdef CONFIG_X86_32
55/**
56 * pcpu_need_numa - determine percpu allocation needs to consider NUMA
57 *
58 * If NUMA is not configured or there is only one NUMA node available,
59 * there is no reason to consider NUMA. This function determines
60 * whether percpu allocation should consider NUMA or not.
61 *
62 * RETURNS:
63 * true if NUMA should be considered; otherwise, false.
64 */
65static bool __init pcpu_need_numa(void)
66{
67#ifdef CONFIG_NEED_MULTIPLE_NODES
68 pg_data_t *last = NULL;
69 unsigned int cpu;
70
71 for_each_possible_cpu(cpu) {
72 int node = early_cpu_to_node(cpu);
73
74 if (node_online(node) && NODE_DATA(node) &&
75 last && last != NODE_DATA(node))
76 return true;
77
78 last = NODE_DATA(node);
79 }
80#endif
81 return false;
82}
83#endif
84
85/**
86 * pcpu_alloc_bootmem - NUMA friendly alloc_bootmem wrapper for percpu
87 * @cpu: cpu to allocate for
88 * @size: size allocation in bytes
89 * @align: alignment
90 *
91 * Allocate @size bytes aligned at @align for cpu @cpu. This wrapper
92 * does the right thing for NUMA regardless of the current
93 * configuration.
94 *
95 * RETURNS:
96 * Pointer to the allocated area on success, NULL on failure.
97 */
98static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size,
99 unsigned long align)
100{
101 const unsigned long goal = __pa(MAX_DMA_ADDRESS);
102#ifdef CONFIG_NEED_MULTIPLE_NODES
103 int node = early_cpu_to_node(cpu);
104 void *ptr;
105
106 if (!node_online(node) || !NODE_DATA(node)) {
107 ptr = __alloc_bootmem_nopanic(size, align, goal);
108 pr_info("cpu %d has no node %d or node-local memory\n",
109 cpu, node);
110 pr_debug("per cpu data for cpu%d %lu bytes at %016lx\n",
111 cpu, size, __pa(ptr));
112 } else {
113 ptr = __alloc_bootmem_node_nopanic(NODE_DATA(node),
114 size, align, goal);
115 pr_debug("per cpu data for cpu%d %lu bytes on node%d at %016lx\n",
116 cpu, size, node, __pa(ptr));
117 }
118 return ptr;
119#else
120 return __alloc_bootmem_nopanic(size, align, goal);
121#endif
122}
123
124/*
125 * Helpers for first chunk memory allocation
126 */
127static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
128{
129 return pcpu_alloc_bootmem(cpu, size, align);
130}
131
132static void __init pcpu_fc_free(void *ptr, size_t size)
133{
134 free_bootmem(__pa(ptr), size);
135}
136
137static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
138{
139#ifdef CONFIG_NEED_MULTIPLE_NODES
140 if (early_cpu_to_node(from) == early_cpu_to_node(to))
141 return LOCAL_DISTANCE;
142 else
143 return REMOTE_DISTANCE;
144#else
145 return LOCAL_DISTANCE;
146#endif
147}
148
149static void __init pcpup_populate_pte(unsigned long addr)
150{
151 populate_extra_pte(addr);
152}
153
154static inline void setup_percpu_segment(int cpu)
155{
156#ifdef CONFIG_X86_32
157 struct desc_struct gdt;
158
159 pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF,
160 0x2 | DESCTYPE_S, 0x8);
161 gdt.s = 1;
162 write_gdt_entry(get_cpu_gdt_table(cpu),
163 GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S);
164#endif
165}
166
167void __init setup_per_cpu_areas(void)
168{
169 unsigned int cpu;
170 unsigned long delta;
171 int rc;
172
173 pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n",
174 NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
175
176 /*
177 * Allocate percpu area. Embedding allocator is our favorite;
178 * however, on NUMA configurations, it can result in very
179 * sparse unit mapping and vmalloc area isn't spacious enough
180 * on 32bit. Use page in that case.
181 */
182#ifdef CONFIG_X86_32
183 if (pcpu_chosen_fc == PCPU_FC_AUTO && pcpu_need_numa())
184 pcpu_chosen_fc = PCPU_FC_PAGE;
185#endif
186 rc = -EINVAL;
187 if (pcpu_chosen_fc != PCPU_FC_PAGE) {
188 const size_t dyn_size = PERCPU_MODULE_RESERVE +
189 PERCPU_DYNAMIC_RESERVE - PERCPU_FIRST_CHUNK_RESERVE;
190 size_t atom_size;
191
192 /*
193 * On 64bit, use PMD_SIZE for atom_size so that embedded
194 * percpu areas are aligned to PMD. This, in the future,
195 * can also allow using PMD mappings in vmalloc area. Use
196 * PAGE_SIZE on 32bit as vmalloc space is highly contended
197 * and large vmalloc area allocs can easily fail.
198 */
199#ifdef CONFIG_X86_64
200 atom_size = PMD_SIZE;
201#else
202 atom_size = PAGE_SIZE;
203#endif
204 rc = pcpu_embed_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
205 dyn_size, atom_size,
206 pcpu_cpu_distance,
207 pcpu_fc_alloc, pcpu_fc_free);
208 if (rc < 0)
209 pr_warning("%s allocator failed (%d), falling back to page size\n",
210 pcpu_fc_names[pcpu_chosen_fc], rc);
211 }
212 if (rc < 0)
213 rc = pcpu_page_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
214 pcpu_fc_alloc, pcpu_fc_free,
215 pcpup_populate_pte);
216 if (rc < 0)
217 panic("cannot initialize percpu area (err=%d)", rc);
218
219 /* alrighty, percpu areas up and running */
220 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
221 for_each_possible_cpu(cpu) {
222 per_cpu_offset(cpu) = delta + pcpu_unit_offsets[cpu];
223 per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
224 per_cpu(cpu_number, cpu) = cpu;
225 setup_percpu_segment(cpu);
226 setup_stack_canary_segment(cpu);
227 /*
228 * Copy data used in early init routines from the
229 * initial arrays to the per cpu data areas. These
230 * arrays then become expendable and the *_early_ptr's
231 * are zeroed indicating that the static arrays are
232 * gone.
233 */
234#ifdef CONFIG_X86_LOCAL_APIC
235 per_cpu(x86_cpu_to_apicid, cpu) =
236 early_per_cpu_map(x86_cpu_to_apicid, cpu);
237 per_cpu(x86_bios_cpu_apicid, cpu) =
238 early_per_cpu_map(x86_bios_cpu_apicid, cpu);
239#endif
240#ifdef CONFIG_X86_32
241 per_cpu(x86_cpu_to_logical_apicid, cpu) =
242 early_per_cpu_map(x86_cpu_to_logical_apicid, cpu);
243#endif
244#ifdef CONFIG_X86_64
245 per_cpu(irq_stack_ptr, cpu) =
246 per_cpu(irq_stack_union.irq_stack, cpu) +
247 IRQ_STACK_SIZE - 64;
248#endif
249#ifdef CONFIG_NUMA
250 per_cpu(x86_cpu_to_node_map, cpu) =
251 early_per_cpu_map(x86_cpu_to_node_map, cpu);
252 /*
253 * Ensure that the boot cpu numa_node is correct when the boot
254 * cpu is on a node that doesn't have memory installed.
255 * Also cpu_up() will call cpu_to_node() for APs when
256 * MEMORY_HOTPLUG is defined, before per_cpu(numa_node) is set
257 * up later with c_init aka intel_init/amd_init.
258 * So set them all (boot cpu and all APs).
259 */
260 set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
261#endif
262 /*
263 * Up to this point, the boot CPU has been using .init.data
264 * area. Reload any changed state for the boot CPU.
265 */
266 if (!cpu)
267 switch_to_new_gdt(cpu);
268 }
269
270 /* indicate the early static arrays will soon be gone */
271#ifdef CONFIG_X86_LOCAL_APIC
272 early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
273 early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
274#endif
275#ifdef CONFIG_X86_32
276 early_per_cpu_ptr(x86_cpu_to_logical_apicid) = NULL;
277#endif
278#ifdef CONFIG_NUMA
279 early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
280#endif
281
282 /* Setup node to cpumask map */
283 setup_node_to_cpumask_map();
284
285 /* Setup cpu initialized, callin, callout masks */
286 setup_cpu_local_masks();
287}
1#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
2
3#include <linux/kernel.h>
4#include <linux/export.h>
5#include <linux/init.h>
6#include <linux/bootmem.h>
7#include <linux/percpu.h>
8#include <linux/kexec.h>
9#include <linux/crash_dump.h>
10#include <linux/smp.h>
11#include <linux/topology.h>
12#include <linux/pfn.h>
13#include <asm/sections.h>
14#include <asm/processor.h>
15#include <asm/desc.h>
16#include <asm/setup.h>
17#include <asm/mpspec.h>
18#include <asm/apicdef.h>
19#include <asm/highmem.h>
20#include <asm/proto.h>
21#include <asm/cpumask.h>
22#include <asm/cpu.h>
23#include <asm/stackprotector.h>
24
25DEFINE_PER_CPU_READ_MOSTLY(int, cpu_number);
26EXPORT_PER_CPU_SYMBOL(cpu_number);
27
28#ifdef CONFIG_X86_64
29#define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
30#else
31#define BOOT_PERCPU_OFFSET 0
32#endif
33
34DEFINE_PER_CPU_READ_MOSTLY(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
35EXPORT_PER_CPU_SYMBOL(this_cpu_off);
36
37unsigned long __per_cpu_offset[NR_CPUS] __ro_after_init = {
38 [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
39};
40EXPORT_SYMBOL(__per_cpu_offset);
41
42/*
43 * On x86_64 symbols referenced from code should be reachable using
44 * 32bit relocations. Reserve space for static percpu variables in
45 * modules so that they are always served from the first chunk which
46 * is located at the percpu segment base. On x86_32, anything can
47 * address anywhere. No need to reserve space in the first chunk.
48 */
49#ifdef CONFIG_X86_64
50#define PERCPU_FIRST_CHUNK_RESERVE PERCPU_MODULE_RESERVE
51#else
52#define PERCPU_FIRST_CHUNK_RESERVE 0
53#endif
54
55#ifdef CONFIG_X86_32
56/**
57 * pcpu_need_numa - determine percpu allocation needs to consider NUMA
58 *
59 * If NUMA is not configured or there is only one NUMA node available,
60 * there is no reason to consider NUMA. This function determines
61 * whether percpu allocation should consider NUMA or not.
62 *
63 * RETURNS:
64 * true if NUMA should be considered; otherwise, false.
65 */
66static bool __init pcpu_need_numa(void)
67{
68#ifdef CONFIG_NEED_MULTIPLE_NODES
69 pg_data_t *last = NULL;
70 unsigned int cpu;
71
72 for_each_possible_cpu(cpu) {
73 int node = early_cpu_to_node(cpu);
74
75 if (node_online(node) && NODE_DATA(node) &&
76 last && last != NODE_DATA(node))
77 return true;
78
79 last = NODE_DATA(node);
80 }
81#endif
82 return false;
83}
84#endif
85
86/**
87 * pcpu_alloc_bootmem - NUMA friendly alloc_bootmem wrapper for percpu
88 * @cpu: cpu to allocate for
89 * @size: size allocation in bytes
90 * @align: alignment
91 *
92 * Allocate @size bytes aligned at @align for cpu @cpu. This wrapper
93 * does the right thing for NUMA regardless of the current
94 * configuration.
95 *
96 * RETURNS:
97 * Pointer to the allocated area on success, NULL on failure.
98 */
99static void * __init pcpu_alloc_bootmem(unsigned int cpu, unsigned long size,
100 unsigned long align)
101{
102 const unsigned long goal = __pa(MAX_DMA_ADDRESS);
103#ifdef CONFIG_NEED_MULTIPLE_NODES
104 int node = early_cpu_to_node(cpu);
105 void *ptr;
106
107 if (!node_online(node) || !NODE_DATA(node)) {
108 ptr = __alloc_bootmem_nopanic(size, align, goal);
109 pr_info("cpu %d has no node %d or node-local memory\n",
110 cpu, node);
111 pr_debug("per cpu data for cpu%d %lu bytes at %016lx\n",
112 cpu, size, __pa(ptr));
113 } else {
114 ptr = __alloc_bootmem_node_nopanic(NODE_DATA(node),
115 size, align, goal);
116 pr_debug("per cpu data for cpu%d %lu bytes on node%d at %016lx\n",
117 cpu, size, node, __pa(ptr));
118 }
119 return ptr;
120#else
121 return __alloc_bootmem_nopanic(size, align, goal);
122#endif
123}
124
125/*
126 * Helpers for first chunk memory allocation
127 */
128static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
129{
130 return pcpu_alloc_bootmem(cpu, size, align);
131}
132
133static void __init pcpu_fc_free(void *ptr, size_t size)
134{
135 free_bootmem(__pa(ptr), size);
136}
137
138static int __init pcpu_cpu_distance(unsigned int from, unsigned int to)
139{
140#ifdef CONFIG_NEED_MULTIPLE_NODES
141 if (early_cpu_to_node(from) == early_cpu_to_node(to))
142 return LOCAL_DISTANCE;
143 else
144 return REMOTE_DISTANCE;
145#else
146 return LOCAL_DISTANCE;
147#endif
148}
149
150static void __init pcpup_populate_pte(unsigned long addr)
151{
152 populate_extra_pte(addr);
153}
154
155static inline void setup_percpu_segment(int cpu)
156{
157#ifdef CONFIG_X86_32
158 struct desc_struct gdt;
159
160 pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF,
161 0x2 | DESCTYPE_S, 0x8);
162 gdt.s = 1;
163 write_gdt_entry(get_cpu_gdt_table(cpu),
164 GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S);
165#endif
166}
167
168void __init setup_per_cpu_areas(void)
169{
170 unsigned int cpu;
171 unsigned long delta;
172 int rc;
173
174 pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n",
175 NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
176
177 /*
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.
182 */
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
187 rc = -EINVAL;
188 if (pcpu_chosen_fc != PCPU_FC_PAGE) {
189 const size_t dyn_size = PERCPU_MODULE_RESERVE +
190 PERCPU_DYNAMIC_RESERVE - PERCPU_FIRST_CHUNK_RESERVE;
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
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);
209 if (rc < 0)
210 pr_warning("%s allocator failed (%d), falling back to page size\n",
211 pcpu_fc_names[pcpu_chosen_fc], rc);
212 }
213 if (rc < 0)
214 rc = pcpu_page_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
215 pcpu_fc_alloc, pcpu_fc_free,
216 pcpup_populate_pte);
217 if (rc < 0)
218 panic("cannot initialize percpu area (err=%d)", rc);
219
220 /* alrighty, percpu areas up and running */
221 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
222 for_each_possible_cpu(cpu) {
223 per_cpu_offset(cpu) = delta + pcpu_unit_offsets[cpu];
224 per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
225 per_cpu(cpu_number, cpu) = cpu;
226 setup_percpu_segment(cpu);
227 setup_stack_canary_segment(cpu);
228 /*
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.
234 */
235#ifdef CONFIG_X86_LOCAL_APIC
236 per_cpu(x86_cpu_to_apicid, cpu) =
237 early_per_cpu_map(x86_cpu_to_apicid, cpu);
238 per_cpu(x86_bios_cpu_apicid, cpu) =
239 early_per_cpu_map(x86_bios_cpu_apicid, cpu);
240 per_cpu(x86_cpu_to_acpiid, cpu) =
241 early_per_cpu_map(x86_cpu_to_acpiid, cpu);
242#endif
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
247#ifdef CONFIG_X86_64
248 per_cpu(irq_stack_ptr, cpu) =
249 per_cpu(irq_stack_union.irq_stack, cpu) +
250 IRQ_STACK_SIZE;
251#endif
252#ifdef CONFIG_NUMA
253 per_cpu(x86_cpu_to_node_map, cpu) =
254 early_per_cpu_map(x86_cpu_to_node_map, cpu);
255 /*
256 * Ensure that the boot cpu numa_node is correct when the boot
257 * cpu is on a node that doesn't have memory installed.
258 * Also cpu_up() will call cpu_to_node() for APs when
259 * MEMORY_HOTPLUG is defined, before per_cpu(numa_node) is set
260 * up later with c_init aka intel_init/amd_init.
261 * So set them all (boot cpu and all APs).
262 */
263 set_cpu_numa_node(cpu, early_cpu_to_node(cpu));
264#endif
265 /*
266 * Up to this point, the boot CPU has been using .init.data
267 * area. Reload any changed state for the boot CPU.
268 */
269 if (!cpu)
270 switch_to_new_gdt(cpu);
271 }
272
273 /* indicate the early static arrays will soon be gone */
274#ifdef CONFIG_X86_LOCAL_APIC
275 early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
276 early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
277 early_per_cpu_ptr(x86_cpu_to_acpiid) = NULL;
278#endif
279#ifdef CONFIG_X86_32
280 early_per_cpu_ptr(x86_cpu_to_logical_apicid) = NULL;
281#endif
282#ifdef CONFIG_NUMA
283 early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
284#endif
285
286 /* Setup node to cpumask map */
287 setup_node_to_cpumask_map();
288
289 /* Setup cpu initialized, callin, callout masks */
290 setup_cpu_local_masks();
291}