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percpu: generalize first chunk allocator selection
[net-next-2.6.git] / arch / x86 / kernel / setup_percpu.c
CommitLineData
4fe29a85
GOC
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>
1ecd2765 6#include <linux/kexec.h>
17b4cceb 7#include <linux/crash_dump.h>
8a87dd9a
JSR
8#include <linux/smp.h>
9#include <linux/topology.h>
5f5d8405 10#include <linux/pfn.h>
4fe29a85
GOC
11#include <asm/sections.h>
12#include <asm/processor.h>
13#include <asm/setup.h>
0fc0906e 14#include <asm/mpspec.h>
76eb4131 15#include <asm/apicdef.h>
1ecd2765 16#include <asm/highmem.h>
1a51e3a0 17#include <asm/proto.h>
06879033 18#include <asm/cpumask.h>
34019be1 19#include <asm/cpu.h>
60a5317f 20#include <asm/stackprotector.h>
76eb4131 21
c90aa894
MT
22#ifdef CONFIG_DEBUG_PER_CPU_MAPS
23# define DBG(x...) printk(KERN_DEBUG x)
24#else
25# define DBG(x...)
26#endif
27
ea927906
BG
28DEFINE_PER_CPU(int, cpu_number);
29EXPORT_PER_CPU_SYMBOL(cpu_number);
ea927906 30
1688401a
BG
31#ifdef CONFIG_X86_64
32#define BOOT_PERCPU_OFFSET ((unsigned long)__per_cpu_load)
33#else
34#define BOOT_PERCPU_OFFSET 0
35#endif
36
37DEFINE_PER_CPU(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
38EXPORT_PER_CPU_SYMBOL(this_cpu_off);
39
9939ddaf 40unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
34019be1 41 [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
9939ddaf 42};
9939ddaf 43EXPORT_SYMBOL(__per_cpu_offset);
4fe29a85 44
6b19b0c2
TH
45/*
46 * On x86_64 symbols referenced from code should be reachable using
47 * 32bit relocations. Reserve space for static percpu variables in
48 * modules so that they are always served from the first chunk which
49 * is located at the percpu segment base. On x86_32, anything can
50 * address anywhere. No need to reserve space in the first chunk.
51 */
52#ifdef CONFIG_X86_64
53#define PERCPU_FIRST_CHUNK_RESERVE PERCPU_MODULE_RESERVE
54#else
55#define PERCPU_FIRST_CHUNK_RESERVE 0
56#endif
57
89c92151
TH
58/**
59 * pcpu_need_numa - determine percpu allocation needs to consider NUMA
60 *
61 * If NUMA is not configured or there is only one NUMA node available,
62 * there is no reason to consider NUMA. This function determines
63 * whether percpu allocation should consider NUMA or not.
64 *
65 * RETURNS:
66 * true if NUMA should be considered; otherwise, false.
67 */
68static bool __init pcpu_need_numa(void)
69{
70#ifdef CONFIG_NEED_MULTIPLE_NODES
71 pg_data_t *last = NULL;
72 unsigned int cpu;
73
74 for_each_possible_cpu(cpu) {
75 int node = early_cpu_to_node(cpu);
76
77 if (node_online(node) && NODE_DATA(node) &&
78 last && last != NODE_DATA(node))
79 return true;
80
81 last = NODE_DATA(node);
82 }
83#endif
84 return false;
85}
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)) {
109 ptr = __alloc_bootmem_nopanic(size, align, goal);
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 {
115 ptr = __alloc_bootmem_node_nopanic(NODE_DATA(node),
116 size, align, goal);
117 pr_debug("per cpu data for cpu%d %lu bytes on node%d at "
118 "%016lx\n", cpu, size, node, __pa(ptr));
119 }
120 return ptr;
121#else
122 return __alloc_bootmem_nopanic(size, align, goal);
123#endif
124}
125
d4b95f80
TH
126/*
127 * Helpers for first chunk memory allocation
128 */
129static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size)
130{
131 return pcpu_alloc_bootmem(cpu, size, size);
132}
133
134static void __init pcpu_fc_free(void *ptr, size_t size)
135{
136 free_bootmem(__pa(ptr), size);
137}
138
8ac83757 139/*
8c4bfc6e 140 * Large page remapping allocator
8ac83757
TH
141 */
142#ifdef CONFIG_NEED_MULTIPLE_NODES
8c4bfc6e 143static void __init pcpul_map(void *ptr, size_t size, void *addr)
8ac83757 144{
8c4bfc6e 145 pmd_t *pmd, pmd_v;
8ac83757 146
8c4bfc6e
TH
147 pmd = populate_extra_pmd((unsigned long)addr);
148 pmd_v = pfn_pmd(page_to_pfn(virt_to_page(ptr)), PAGE_KERNEL_LARGE);
149 set_pmd(pmd, pmd_v);
8ac83757
TH
150}
151
a530b795
TH
152static int pcpu_lpage_cpu_distance(unsigned int from, unsigned int to)
153{
154 if (early_cpu_to_node(from) == early_cpu_to_node(to))
155 return LOCAL_DISTANCE;
156 else
157 return REMOTE_DISTANCE;
158}
159
fa8a7094 160static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen)
8ac83757 161{
8c4bfc6e 162 size_t reserve = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
a530b795
TH
163 size_t dyn_size = reserve - PERCPU_FIRST_CHUNK_RESERVE;
164 size_t unit_map_size, unit_size;
165 int *unit_map;
166 int nr_units;
167 ssize_t ret;
168
169 /* on non-NUMA, embedding is better */
170 if (!chosen && !pcpu_need_numa())
171 return -EINVAL;
172
173 /* need PSE */
174 if (!cpu_has_pse) {
175 pr_warning("PERCPU: lpage allocator requires PSE\n");
176 return -EINVAL;
177 }
8ac83757 178
a530b795 179 /* allocate and build unit_map */
384be2b1 180 unit_map_size = nr_cpu_ids * sizeof(int);
a530b795
TH
181 unit_map = alloc_bootmem_nopanic(unit_map_size);
182 if (!unit_map) {
183 pr_warning("PERCPU: failed to allocate unit_map\n");
184 return -ENOMEM;
185 }
186
187 ret = pcpu_lpage_build_unit_map(static_size,
188 PERCPU_FIRST_CHUNK_RESERVE,
189 &dyn_size, &unit_size, PMD_SIZE,
190 unit_map, pcpu_lpage_cpu_distance);
191 if (ret < 0) {
192 pr_warning("PERCPU: failed to build unit_map\n");
193 goto out_free;
194 }
195 nr_units = ret;
196
197 /* do the parameters look okay? */
0017c869
TH
198 if (!chosen) {
199 size_t vm_size = VMALLOC_END - VMALLOC_START;
a530b795 200 size_t tot_size = nr_units * unit_size;
0017c869
TH
201
202 /* don't consume more than 20% of vmalloc area */
203 if (tot_size > vm_size / 5) {
204 pr_info("PERCPU: too large chunk size %zuMB for "
205 "large page remap\n", tot_size >> 20);
a530b795
TH
206 ret = -EINVAL;
207 goto out_free;
0017c869
TH
208 }
209 }
8ac83757 210
a530b795
TH
211 ret = pcpu_lpage_first_chunk(static_size, PERCPU_FIRST_CHUNK_RESERVE,
212 dyn_size, unit_size, PMD_SIZE,
213 unit_map, nr_units,
214 pcpu_fc_alloc, pcpu_fc_free, pcpul_map);
215out_free:
216 if (ret < 0)
217 free_bootmem(__pa(unit_map), unit_map_size);
218 return ret;
8ac83757
TH
219}
220#else
fa8a7094 221static ssize_t __init setup_pcpu_lpage(size_t static_size, bool chosen)
8ac83757
TH
222{
223 return -EINVAL;
224}
225#endif
226
89c92151
TH
227/*
228 * Embedding allocator
229 *
230 * The first chunk is sized to just contain the static area plus
66c3a757
TH
231 * module and dynamic reserves and embedded into linear physical
232 * mapping so that it can use PMD mapping without additional TLB
233 * pressure.
89c92151 234 */
fa8a7094 235static ssize_t __init setup_pcpu_embed(size_t static_size, bool chosen)
89c92151 236{
66c3a757 237 size_t reserve = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
89c92151
TH
238
239 /*
240 * If large page isn't supported, there's no benefit in doing
241 * this. Also, embedding allocation doesn't play well with
242 * NUMA.
243 */
fa8a7094 244 if (!chosen && (!cpu_has_pse || pcpu_need_numa()))
89c92151
TH
245 return -EINVAL;
246
66c3a757 247 return pcpu_embed_first_chunk(static_size, PERCPU_FIRST_CHUNK_RESERVE,
788e5abc 248 reserve - PERCPU_FIRST_CHUNK_RESERVE);
89c92151
TH
249}
250
5f5d8405 251/*
00ae4064 252 * Page allocator
5f5d8405 253 *
00ae4064
TH
254 * Boring fallback 4k page allocator. This allocator puts more
255 * pressure on PTE TLBs but other than that behaves nicely on both UMA
256 * and NUMA.
5f5d8405 257 */
00ae4064 258static void __init pcpup_populate_pte(unsigned long addr)
458a3e64
TH
259{
260 populate_extra_pte(addr);
261}
262
00ae4064 263static ssize_t __init setup_pcpu_page(size_t static_size)
5f5d8405 264{
00ae4064
TH
265 return pcpu_page_first_chunk(static_size, PERCPU_FIRST_CHUNK_RESERVE,
266 pcpu_fc_alloc, pcpu_fc_free,
267 pcpup_populate_pte);
5f5d8405
TH
268}
269
b2d2f431
BG
270static inline void setup_percpu_segment(int cpu)
271{
272#ifdef CONFIG_X86_32
273 struct desc_struct gdt;
274
275 pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF,
276 0x2 | DESCTYPE_S, 0x8);
277 gdt.s = 1;
278 write_gdt_entry(get_cpu_gdt_table(cpu),
279 GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S);
280#endif
281}
282
4fe29a85
GOC
283void __init setup_per_cpu_areas(void)
284{
5f5d8405
TH
285 size_t static_size = __per_cpu_end - __per_cpu_start;
286 unsigned int cpu;
11124411
TH
287 unsigned long delta;
288 size_t pcpu_unit_size;
5f5d8405 289 ssize_t ret;
a1681965 290
ab14398a 291 pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n",
a1681965 292 NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
11124411 293
8ac83757
TH
294 /*
295 * Allocate percpu area. If PSE is supported, try to make use
296 * of large page mappings. Please read comments on top of
297 * each allocator for details.
298 */
fa8a7094 299 ret = -EINVAL;
f58dc01b
TH
300 if (pcpu_chosen_fc != PCPU_FC_AUTO) {
301 if (pcpu_chosen_fc != PCPU_FC_PAGE) {
302 if (pcpu_chosen_fc == PCPU_FC_LPAGE)
fa8a7094 303 ret = setup_pcpu_lpage(static_size, true);
fa8a7094 304 else
f58dc01b
TH
305 ret = setup_pcpu_embed(static_size, true);
306
fa8a7094
TH
307 if (ret < 0)
308 pr_warning("PERCPU: %s allocator failed (%zd), "
00ae4064 309 "falling back to page size\n",
f58dc01b 310 pcpu_fc_names[pcpu_chosen_fc], ret);
fa8a7094
TH
311 }
312 } else {
313 ret = setup_pcpu_lpage(static_size, false);
314 if (ret < 0)
315 ret = setup_pcpu_embed(static_size, false);
316 }
89c92151 317 if (ret < 0)
00ae4064 318 ret = setup_pcpu_page(static_size);
5f5d8405
TH
319 if (ret < 0)
320 panic("cannot allocate static percpu area (%zu bytes, err=%zd)",
321 static_size, ret);
1a51e3a0 322
5f5d8405 323 pcpu_unit_size = ret;
11124411 324
5f5d8405 325 /* alrighty, percpu areas up and running */
11124411
TH
326 delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
327 for_each_possible_cpu(cpu) {
a530b795
TH
328 per_cpu_offset(cpu) =
329 delta + pcpu_unit_map[cpu] * pcpu_unit_size;
26f80bd6 330 per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
ea927906 331 per_cpu(cpu_number, cpu) = cpu;
b2d2f431 332 setup_percpu_segment(cpu);
60a5317f 333 setup_stack_canary_segment(cpu);
0d77e7f0 334 /*
cf3997f5
TH
335 * Copy data used in early init routines from the
336 * initial arrays to the per cpu data areas. These
337 * arrays then become expendable and the *_early_ptr's
338 * are zeroed indicating that the static arrays are
339 * gone.
0d77e7f0 340 */
ec70de8b 341#ifdef CONFIG_X86_LOCAL_APIC
0d77e7f0 342 per_cpu(x86_cpu_to_apicid, cpu) =
cf3997f5 343 early_per_cpu_map(x86_cpu_to_apicid, cpu);
0d77e7f0 344 per_cpu(x86_bios_cpu_apicid, cpu) =
cf3997f5 345 early_per_cpu_map(x86_bios_cpu_apicid, cpu);
ec70de8b 346#endif
1a51e3a0 347#ifdef CONFIG_X86_64
26f80bd6 348 per_cpu(irq_stack_ptr, cpu) =
cf3997f5
TH
349 per_cpu(irq_stack_union.irq_stack, cpu) +
350 IRQ_STACK_SIZE - 64;
6470aff6
BG
351#ifdef CONFIG_NUMA
352 per_cpu(x86_cpu_to_node_map, cpu) =
cf3997f5 353 early_per_cpu_map(x86_cpu_to_node_map, cpu);
2697fbd5 354#endif
6470aff6 355#endif
1a51e3a0 356 /*
34019be1 357 * Up to this point, the boot CPU has been using .data.init
2697fbd5 358 * area. Reload any changed state for the boot CPU.
1a51e3a0 359 */
34019be1 360 if (cpu == boot_cpu_id)
552be871 361 switch_to_new_gdt(cpu);
4fe29a85
GOC
362 }
363
0d77e7f0 364 /* indicate the early static arrays will soon be gone */
22f25138 365#ifdef CONFIG_X86_LOCAL_APIC
0d77e7f0
BG
366 early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
367 early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
22f25138 368#endif
6470aff6 369#if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
0d77e7f0
BG
370 early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
371#endif
9f0e8d04 372
35d5a9a6
YL
373#if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
374 /*
375 * make sure boot cpu node_number is right, when boot cpu is on the
376 * node that doesn't have mem installed
377 */
378 per_cpu(node_number, boot_cpu_id) = cpu_to_node(boot_cpu_id);
379#endif
380
9f248bde
MT
381 /* Setup node to cpumask map */
382 setup_node_to_cpumask_map();
c2d1cec1
MT
383
384 /* Setup cpu initialized, callin, callout masks */
385 setup_cpu_local_masks();
4fe29a85 386}