percpu: introduce pcpu_alloc_info and pcpu_group_info
[linux-2.6.git] / arch / x86 / kernel / setup_percpu.c
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 <linux/kexec.h>
7 #include <linux/crash_dump.h>
8 #include <linux/smp.h>
9 #include <linux/topology.h>
10 #include <linux/pfn.h>
11 #include <asm/sections.h>
12 #include <asm/processor.h>
13 #include <asm/setup.h>
14 #include <asm/mpspec.h>
15 #include <asm/apicdef.h>
16 #include <asm/highmem.h>
17 #include <asm/proto.h>
18 #include <asm/cpumask.h>
19 #include <asm/cpu.h>
20 #include <asm/stackprotector.h>
21
22 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
23 # define DBG(x...) printk(KERN_DEBUG x)
24 #else
25 # define DBG(x...)
26 #endif
27
28 DEFINE_PER_CPU(int, cpu_number);
29 EXPORT_PER_CPU_SYMBOL(cpu_number);
30
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
37 DEFINE_PER_CPU(unsigned long, this_cpu_off) = BOOT_PERCPU_OFFSET;
38 EXPORT_PER_CPU_SYMBOL(this_cpu_off);
39
40 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly = {
41         [0 ... NR_CPUS-1] = BOOT_PERCPU_OFFSET,
42 };
43 EXPORT_SYMBOL(__per_cpu_offset);
44
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
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  */
68 static 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
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  */
100 static 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
126 /*
127  * Helpers for first chunk memory allocation
128  */
129 static void * __init pcpu_fc_alloc(unsigned int cpu, size_t size, size_t align)
130 {
131         return pcpu_alloc_bootmem(cpu, size, align);
132 }
133
134 static void __init pcpu_fc_free(void *ptr, size_t size)
135 {
136         free_bootmem(__pa(ptr), size);
137 }
138
139 /*
140  * Large page remapping allocator
141  */
142 #ifdef CONFIG_NEED_MULTIPLE_NODES
143 static void __init pcpul_map(void *ptr, size_t size, void *addr)
144 {
145         pmd_t *pmd, pmd_v;
146
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);
150 }
151
152 static 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
160 static ssize_t __init setup_pcpu_lpage(bool chosen)
161 {
162         size_t reserve = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
163         size_t dyn_size = reserve - PERCPU_FIRST_CHUNK_RESERVE;
164         struct pcpu_alloc_info *ai;
165         ssize_t ret;
166
167         /* on non-NUMA, embedding is better */
168         if (!chosen && !pcpu_need_numa())
169                 return -EINVAL;
170
171         /* need PSE */
172         if (!cpu_has_pse) {
173                 pr_warning("PERCPU: lpage allocator requires PSE\n");
174                 return -EINVAL;
175         }
176
177         /* allocate and build unit_map */
178         ai = pcpu_build_alloc_info(PERCPU_FIRST_CHUNK_RESERVE, dyn_size,
179                                    PMD_SIZE, pcpu_lpage_cpu_distance);
180         if (IS_ERR(ai)) {
181                 pr_warning("PERCPU: failed to build unit_map (%ld)\n",
182                            PTR_ERR(ai));
183                 return PTR_ERR(ai);
184         }
185
186         /* do the parameters look okay? */
187         if (!chosen) {
188                 size_t vm_size = VMALLOC_END - VMALLOC_START;
189                 size_t tot_size = 0;
190                 int group;
191
192                 for (group = 0; group < ai->nr_groups; group++)
193                         tot_size += ai->unit_size * ai->groups[group].nr_units;
194
195                 /* don't consume more than 20% of vmalloc area */
196                 if (tot_size > vm_size / 5) {
197                         pr_info("PERCPU: too large chunk size %zuMB for "
198                                 "large page remap\n", tot_size >> 20);
199                         ret = -EINVAL;
200                         goto out_free;
201                 }
202         }
203
204         ret = pcpu_lpage_first_chunk(ai, pcpu_fc_alloc, pcpu_fc_free,
205                                      pcpul_map);
206 out_free:
207         pcpu_free_alloc_info(ai);
208         return ret;
209 }
210 #else
211 static ssize_t __init setup_pcpu_lpage(bool chosen)
212 {
213         return -EINVAL;
214 }
215 #endif
216
217 /*
218  * Embedding allocator
219  *
220  * The first chunk is sized to just contain the static area plus
221  * module and dynamic reserves and embedded into linear physical
222  * mapping so that it can use PMD mapping without additional TLB
223  * pressure.
224  */
225 static ssize_t __init setup_pcpu_embed(bool chosen)
226 {
227         size_t reserve = PERCPU_MODULE_RESERVE + PERCPU_DYNAMIC_RESERVE;
228
229         /*
230          * If large page isn't supported, there's no benefit in doing
231          * this.  Also, embedding allocation doesn't play well with
232          * NUMA.
233          */
234         if (!chosen && (!cpu_has_pse || pcpu_need_numa()))
235                 return -EINVAL;
236
237         return pcpu_embed_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
238                                       reserve - PERCPU_FIRST_CHUNK_RESERVE);
239 }
240
241 /*
242  * Page allocator
243  *
244  * Boring fallback 4k page allocator.  This allocator puts more
245  * pressure on PTE TLBs but other than that behaves nicely on both UMA
246  * and NUMA.
247  */
248 static void __init pcpup_populate_pte(unsigned long addr)
249 {
250         populate_extra_pte(addr);
251 }
252
253 static ssize_t __init setup_pcpu_page(void)
254 {
255         return pcpu_page_first_chunk(PERCPU_FIRST_CHUNK_RESERVE,
256                                      pcpu_fc_alloc, pcpu_fc_free,
257                                      pcpup_populate_pte);
258 }
259
260 static inline void setup_percpu_segment(int cpu)
261 {
262 #ifdef CONFIG_X86_32
263         struct desc_struct gdt;
264
265         pack_descriptor(&gdt, per_cpu_offset(cpu), 0xFFFFF,
266                         0x2 | DESCTYPE_S, 0x8);
267         gdt.s = 1;
268         write_gdt_entry(get_cpu_gdt_table(cpu),
269                         GDT_ENTRY_PERCPU, &gdt, DESCTYPE_S);
270 #endif
271 }
272
273 void __init setup_per_cpu_areas(void)
274 {
275         unsigned int cpu;
276         unsigned long delta;
277         size_t pcpu_unit_size;
278         ssize_t ret;
279
280         pr_info("NR_CPUS:%d nr_cpumask_bits:%d nr_cpu_ids:%d nr_node_ids:%d\n",
281                 NR_CPUS, nr_cpumask_bits, nr_cpu_ids, nr_node_ids);
282
283         /*
284          * Allocate percpu area.  If PSE is supported, try to make use
285          * of large page mappings.  Please read comments on top of
286          * each allocator for details.
287          */
288         ret = -EINVAL;
289         if (pcpu_chosen_fc != PCPU_FC_AUTO) {
290                 if (pcpu_chosen_fc != PCPU_FC_PAGE) {
291                         if (pcpu_chosen_fc == PCPU_FC_LPAGE)
292                                 ret = setup_pcpu_lpage(true);
293                         else
294                                 ret = setup_pcpu_embed(true);
295
296                         if (ret < 0)
297                                 pr_warning("PERCPU: %s allocator failed (%zd), "
298                                            "falling back to page size\n",
299                                            pcpu_fc_names[pcpu_chosen_fc], ret);
300                 }
301         } else {
302                 ret = setup_pcpu_lpage(false);
303                 if (ret < 0)
304                         ret = setup_pcpu_embed(false);
305         }
306         if (ret < 0)
307                 ret = setup_pcpu_page();
308         if (ret < 0)
309                 panic("cannot initialize percpu area (err=%zd)", ret);
310
311         pcpu_unit_size = ret;
312
313         /* alrighty, percpu areas up and running */
314         delta = (unsigned long)pcpu_base_addr - (unsigned long)__per_cpu_start;
315         for_each_possible_cpu(cpu) {
316                 per_cpu_offset(cpu) =
317                         delta + pcpu_unit_map[cpu] * pcpu_unit_size;
318                 per_cpu(this_cpu_off, cpu) = per_cpu_offset(cpu);
319                 per_cpu(cpu_number, cpu) = cpu;
320                 setup_percpu_segment(cpu);
321                 setup_stack_canary_segment(cpu);
322                 /*
323                  * Copy data used in early init routines from the
324                  * initial arrays to the per cpu data areas.  These
325                  * arrays then become expendable and the *_early_ptr's
326                  * are zeroed indicating that the static arrays are
327                  * gone.
328                  */
329 #ifdef CONFIG_X86_LOCAL_APIC
330                 per_cpu(x86_cpu_to_apicid, cpu) =
331                         early_per_cpu_map(x86_cpu_to_apicid, cpu);
332                 per_cpu(x86_bios_cpu_apicid, cpu) =
333                         early_per_cpu_map(x86_bios_cpu_apicid, cpu);
334 #endif
335 #ifdef CONFIG_X86_64
336                 per_cpu(irq_stack_ptr, cpu) =
337                         per_cpu(irq_stack_union.irq_stack, cpu) +
338                         IRQ_STACK_SIZE - 64;
339 #ifdef CONFIG_NUMA
340                 per_cpu(x86_cpu_to_node_map, cpu) =
341                         early_per_cpu_map(x86_cpu_to_node_map, cpu);
342 #endif
343 #endif
344                 /*
345                  * Up to this point, the boot CPU has been using .data.init
346                  * area.  Reload any changed state for the boot CPU.
347                  */
348                 if (cpu == boot_cpu_id)
349                         switch_to_new_gdt(cpu);
350         }
351
352         /* indicate the early static arrays will soon be gone */
353 #ifdef CONFIG_X86_LOCAL_APIC
354         early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
355         early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
356 #endif
357 #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
358         early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
359 #endif
360
361 #if defined(CONFIG_X86_64) && defined(CONFIG_NUMA)
362         /*
363          * make sure boot cpu node_number is right, when boot cpu is on the
364          * node that doesn't have mem installed
365          */
366         per_cpu(node_number, boot_cpu_id) = cpu_to_node(boot_cpu_id);
367 #endif
368
369         /* Setup node to cpumask map */
370         setup_node_to_cpumask_map();
371
372         /* Setup cpu initialized, callin, callout masks */
373         setup_cpu_local_masks();
374 }