xref: /openbmc/linux/arch/x86/kernel/setup_percpu.c (revision 545e4006)
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 <asm/smp.h>
9 #include <asm/percpu.h>
10 #include <asm/sections.h>
11 #include <asm/processor.h>
12 #include <asm/setup.h>
13 #include <asm/topology.h>
14 #include <asm/mpspec.h>
15 #include <asm/apicdef.h>
16 #include <asm/highmem.h>
17 
18 #ifdef CONFIG_X86_LOCAL_APIC
19 unsigned int num_processors;
20 unsigned disabled_cpus __cpuinitdata;
21 /* Processor that is doing the boot up */
22 unsigned int boot_cpu_physical_apicid = -1U;
23 unsigned int max_physical_apicid;
24 EXPORT_SYMBOL(boot_cpu_physical_apicid);
25 
26 /* Bitmask of physically existing CPUs */
27 physid_mask_t phys_cpu_present_map;
28 #endif
29 
30 /* map cpu index to physical APIC ID */
31 DEFINE_EARLY_PER_CPU(u16, x86_cpu_to_apicid, BAD_APICID);
32 DEFINE_EARLY_PER_CPU(u16, x86_bios_cpu_apicid, BAD_APICID);
33 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_apicid);
34 EXPORT_EARLY_PER_CPU_SYMBOL(x86_bios_cpu_apicid);
35 
36 #if defined(CONFIG_NUMA) && defined(CONFIG_X86_64)
37 #define	X86_64_NUMA	1
38 
39 /* map cpu index to node index */
40 DEFINE_EARLY_PER_CPU(int, x86_cpu_to_node_map, NUMA_NO_NODE);
41 EXPORT_EARLY_PER_CPU_SYMBOL(x86_cpu_to_node_map);
42 
43 /* which logical CPUs are on which nodes */
44 cpumask_t *node_to_cpumask_map;
45 EXPORT_SYMBOL(node_to_cpumask_map);
46 
47 /* setup node_to_cpumask_map */
48 static void __init setup_node_to_cpumask_map(void);
49 
50 #else
51 static inline void setup_node_to_cpumask_map(void) { }
52 #endif
53 
54 #if defined(CONFIG_HAVE_SETUP_PER_CPU_AREA) && defined(CONFIG_X86_SMP)
55 /*
56  * Copy data used in early init routines from the initial arrays to the
57  * per cpu data areas.  These arrays then become expendable and the
58  * *_early_ptr's are zeroed indicating that the static arrays are gone.
59  */
60 static void __init setup_per_cpu_maps(void)
61 {
62 	int cpu;
63 
64 	for_each_possible_cpu(cpu) {
65 		per_cpu(x86_cpu_to_apicid, cpu) =
66 				early_per_cpu_map(x86_cpu_to_apicid, cpu);
67 		per_cpu(x86_bios_cpu_apicid, cpu) =
68 				early_per_cpu_map(x86_bios_cpu_apicid, cpu);
69 #ifdef X86_64_NUMA
70 		per_cpu(x86_cpu_to_node_map, cpu) =
71 				early_per_cpu_map(x86_cpu_to_node_map, cpu);
72 #endif
73 	}
74 
75 	/* indicate the early static arrays will soon be gone */
76 	early_per_cpu_ptr(x86_cpu_to_apicid) = NULL;
77 	early_per_cpu_ptr(x86_bios_cpu_apicid) = NULL;
78 #ifdef X86_64_NUMA
79 	early_per_cpu_ptr(x86_cpu_to_node_map) = NULL;
80 #endif
81 }
82 
83 #ifdef CONFIG_HAVE_CPUMASK_OF_CPU_MAP
84 cpumask_t *cpumask_of_cpu_map __read_mostly;
85 EXPORT_SYMBOL(cpumask_of_cpu_map);
86 
87 /* requires nr_cpu_ids to be initialized */
88 static void __init setup_cpumask_of_cpu(void)
89 {
90 	int i;
91 
92 	/* alloc_bootmem zeroes memory */
93 	cpumask_of_cpu_map = alloc_bootmem_low(sizeof(cpumask_t) * nr_cpu_ids);
94 	for (i = 0; i < nr_cpu_ids; i++)
95 		cpu_set(i, cpumask_of_cpu_map[i]);
96 }
97 #else
98 static inline void setup_cpumask_of_cpu(void) { }
99 #endif
100 
101 #ifdef CONFIG_X86_32
102 /*
103  * Great future not-so-futuristic plan: make i386 and x86_64 do it
104  * the same way
105  */
106 unsigned long __per_cpu_offset[NR_CPUS] __read_mostly;
107 EXPORT_SYMBOL(__per_cpu_offset);
108 static inline void setup_cpu_pda_map(void) { }
109 
110 #elif !defined(CONFIG_SMP)
111 static inline void setup_cpu_pda_map(void) { }
112 
113 #else /* CONFIG_SMP && CONFIG_X86_64 */
114 
115 /*
116  * Allocate cpu_pda pointer table and array via alloc_bootmem.
117  */
118 static void __init setup_cpu_pda_map(void)
119 {
120 	char *pda;
121 	struct x8664_pda **new_cpu_pda;
122 	unsigned long size;
123 	int cpu;
124 
125 	size = roundup(sizeof(struct x8664_pda), cache_line_size());
126 
127 	/* allocate cpu_pda array and pointer table */
128 	{
129 		unsigned long tsize = nr_cpu_ids * sizeof(void *);
130 		unsigned long asize = size * (nr_cpu_ids - 1);
131 
132 		tsize = roundup(tsize, cache_line_size());
133 		new_cpu_pda = alloc_bootmem(tsize + asize);
134 		pda = (char *)new_cpu_pda + tsize;
135 	}
136 
137 	/* initialize pointer table to static pda's */
138 	for_each_possible_cpu(cpu) {
139 		if (cpu == 0) {
140 			/* leave boot cpu pda in place */
141 			new_cpu_pda[0] = cpu_pda(0);
142 			continue;
143 		}
144 		new_cpu_pda[cpu] = (struct x8664_pda *)pda;
145 		new_cpu_pda[cpu]->in_bootmem = 1;
146 		pda += size;
147 	}
148 
149 	/* point to new pointer table */
150 	_cpu_pda = new_cpu_pda;
151 }
152 #endif
153 
154 /*
155  * Great future plan:
156  * Declare PDA itself and support (irqstack,tss,pgd) as per cpu data.
157  * Always point %gs to its beginning
158  */
159 void __init setup_per_cpu_areas(void)
160 {
161 	ssize_t size = PERCPU_ENOUGH_ROOM;
162 	char *ptr;
163 	int cpu;
164 
165 	/* Setup cpu_pda map */
166 	setup_cpu_pda_map();
167 
168 	/* Copy section for each CPU (we discard the original) */
169 	size = PERCPU_ENOUGH_ROOM;
170 	printk(KERN_INFO "PERCPU: Allocating %zd bytes of per cpu data\n",
171 			  size);
172 
173 	for_each_possible_cpu(cpu) {
174 #ifndef CONFIG_NEED_MULTIPLE_NODES
175 		ptr = alloc_bootmem_pages(size);
176 #else
177 		int node = early_cpu_to_node(cpu);
178 		if (!node_online(node) || !NODE_DATA(node)) {
179 			ptr = alloc_bootmem_pages(size);
180 			printk(KERN_INFO
181 			       "cpu %d has no node %d or node-local memory\n",
182 				cpu, node);
183 		}
184 		else
185 			ptr = alloc_bootmem_pages_node(NODE_DATA(node), size);
186 #endif
187 		per_cpu_offset(cpu) = ptr - __per_cpu_start;
188 		memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
189 
190 	}
191 
192 	printk(KERN_DEBUG "NR_CPUS: %d, nr_cpu_ids: %d, nr_node_ids %d\n",
193 		NR_CPUS, nr_cpu_ids, nr_node_ids);
194 
195 	/* Setup percpu data maps */
196 	setup_per_cpu_maps();
197 
198 	/* Setup node to cpumask map */
199 	setup_node_to_cpumask_map();
200 
201 	/* Setup cpumask_of_cpu map */
202 	setup_cpumask_of_cpu();
203 }
204 
205 #endif
206 
207 #ifdef X86_64_NUMA
208 
209 /*
210  * Allocate node_to_cpumask_map based on number of available nodes
211  * Requires node_possible_map to be valid.
212  *
213  * Note: node_to_cpumask() is not valid until after this is done.
214  */
215 static void __init setup_node_to_cpumask_map(void)
216 {
217 	unsigned int node, num = 0;
218 	cpumask_t *map;
219 
220 	/* setup nr_node_ids if not done yet */
221 	if (nr_node_ids == MAX_NUMNODES) {
222 		for_each_node_mask(node, node_possible_map)
223 			num = node;
224 		nr_node_ids = num + 1;
225 	}
226 
227 	/* allocate the map */
228 	map = alloc_bootmem_low(nr_node_ids * sizeof(cpumask_t));
229 
230 	pr_debug(KERN_DEBUG "Node to cpumask map at %p for %d nodes\n",
231 		 map, nr_node_ids);
232 
233 	/* node_to_cpumask() will now work */
234 	node_to_cpumask_map = map;
235 }
236 
237 void __cpuinit numa_set_node(int cpu, int node)
238 {
239 	int *cpu_to_node_map = early_per_cpu_ptr(x86_cpu_to_node_map);
240 
241 	if (cpu_pda(cpu) && node != NUMA_NO_NODE)
242 		cpu_pda(cpu)->nodenumber = node;
243 
244 	if (cpu_to_node_map)
245 		cpu_to_node_map[cpu] = node;
246 
247 	else if (per_cpu_offset(cpu))
248 		per_cpu(x86_cpu_to_node_map, cpu) = node;
249 
250 	else
251 		pr_debug("Setting node for non-present cpu %d\n", cpu);
252 }
253 
254 void __cpuinit numa_clear_node(int cpu)
255 {
256 	numa_set_node(cpu, NUMA_NO_NODE);
257 }
258 
259 #ifndef CONFIG_DEBUG_PER_CPU_MAPS
260 
261 void __cpuinit numa_add_cpu(int cpu)
262 {
263 	cpu_set(cpu, node_to_cpumask_map[early_cpu_to_node(cpu)]);
264 }
265 
266 void __cpuinit numa_remove_cpu(int cpu)
267 {
268 	cpu_clear(cpu, node_to_cpumask_map[cpu_to_node(cpu)]);
269 }
270 
271 #else /* CONFIG_DEBUG_PER_CPU_MAPS */
272 
273 /*
274  * --------- debug versions of the numa functions ---------
275  */
276 static void __cpuinit numa_set_cpumask(int cpu, int enable)
277 {
278 	int node = cpu_to_node(cpu);
279 	cpumask_t *mask;
280 	char buf[64];
281 
282 	if (node_to_cpumask_map == NULL) {
283 		printk(KERN_ERR "node_to_cpumask_map NULL\n");
284 		dump_stack();
285 		return;
286 	}
287 
288 	mask = &node_to_cpumask_map[node];
289 	if (enable)
290 		cpu_set(cpu, *mask);
291 	else
292 		cpu_clear(cpu, *mask);
293 
294 	cpulist_scnprintf(buf, sizeof(buf), *mask);
295 	printk(KERN_DEBUG "%s cpu %d node %d: mask now %s\n",
296 		enable? "numa_add_cpu":"numa_remove_cpu", cpu, node, buf);
297  }
298 
299 void __cpuinit numa_add_cpu(int cpu)
300 {
301 	numa_set_cpumask(cpu, 1);
302 }
303 
304 void __cpuinit numa_remove_cpu(int cpu)
305 {
306 	numa_set_cpumask(cpu, 0);
307 }
308 
309 int cpu_to_node(int cpu)
310 {
311 	if (early_per_cpu_ptr(x86_cpu_to_node_map)) {
312 		printk(KERN_WARNING
313 			"cpu_to_node(%d): usage too early!\n", cpu);
314 		dump_stack();
315 		return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
316 	}
317 	return per_cpu(x86_cpu_to_node_map, cpu);
318 }
319 EXPORT_SYMBOL(cpu_to_node);
320 
321 /*
322  * Same function as cpu_to_node() but used if called before the
323  * per_cpu areas are setup.
324  */
325 int early_cpu_to_node(int cpu)
326 {
327 	if (early_per_cpu_ptr(x86_cpu_to_node_map))
328 		return early_per_cpu_ptr(x86_cpu_to_node_map)[cpu];
329 
330 	if (!per_cpu_offset(cpu)) {
331 		printk(KERN_WARNING
332 			"early_cpu_to_node(%d): no per_cpu area!\n", cpu);
333 		dump_stack();
334 		return NUMA_NO_NODE;
335 	}
336 	return per_cpu(x86_cpu_to_node_map, cpu);
337 }
338 
339 
340 /* empty cpumask */
341 static const cpumask_t cpu_mask_none;
342 
343 /*
344  * Returns a pointer to the bitmask of CPUs on Node 'node'.
345  */
346 const cpumask_t *_node_to_cpumask_ptr(int node)
347 {
348 	if (node_to_cpumask_map == NULL) {
349 		printk(KERN_WARNING
350 			"_node_to_cpumask_ptr(%d): no node_to_cpumask_map!\n",
351 			node);
352 		dump_stack();
353 		return (const cpumask_t *)&cpu_online_map;
354 	}
355 	if (node >= nr_node_ids) {
356 		printk(KERN_WARNING
357 			"_node_to_cpumask_ptr(%d): node > nr_node_ids(%d)\n",
358 			node, nr_node_ids);
359 		dump_stack();
360 		return &cpu_mask_none;
361 	}
362 	return &node_to_cpumask_map[node];
363 }
364 EXPORT_SYMBOL(_node_to_cpumask_ptr);
365 
366 /*
367  * Returns a bitmask of CPUs on Node 'node'.
368  *
369  * Side note: this function creates the returned cpumask on the stack
370  * so with a high NR_CPUS count, excessive stack space is used.  The
371  * node_to_cpumask_ptr function should be used whenever possible.
372  */
373 cpumask_t node_to_cpumask(int node)
374 {
375 	if (node_to_cpumask_map == NULL) {
376 		printk(KERN_WARNING
377 			"node_to_cpumask(%d): no node_to_cpumask_map!\n", node);
378 		dump_stack();
379 		return cpu_online_map;
380 	}
381 	if (node >= nr_node_ids) {
382 		printk(KERN_WARNING
383 			"node_to_cpumask(%d): node > nr_node_ids(%d)\n",
384 			node, nr_node_ids);
385 		dump_stack();
386 		return cpu_mask_none;
387 	}
388 	return node_to_cpumask_map[node];
389 }
390 EXPORT_SYMBOL(node_to_cpumask);
391 
392 /*
393  * --------- end of debug versions of the numa functions ---------
394  */
395 
396 #endif /* CONFIG_DEBUG_PER_CPU_MAPS */
397 
398 #endif /* X86_64_NUMA */
399 
400