xref: /linux/arch/powerpc/kernel/sysfs.c (revision 606d099cdd1080bbb50ea50dc52d98252f8f10a1)
1 #include <linux/sysdev.h>
2 #include <linux/cpu.h>
3 #include <linux/smp.h>
4 #include <linux/percpu.h>
5 #include <linux/init.h>
6 #include <linux/sched.h>
7 #include <linux/module.h>
8 #include <linux/nodemask.h>
9 #include <linux/cpumask.h>
10 #include <linux/notifier.h>
11 
12 #include <asm/current.h>
13 #include <asm/processor.h>
14 #include <asm/cputable.h>
15 #include <asm/firmware.h>
16 #include <asm/hvcall.h>
17 #include <asm/prom.h>
18 #include <asm/paca.h>
19 #include <asm/lppaca.h>
20 #include <asm/machdep.h>
21 #include <asm/smp.h>
22 
23 static DEFINE_PER_CPU(struct cpu, cpu_devices);
24 
25 /* SMT stuff */
26 
27 #ifdef CONFIG_PPC_MULTIPLATFORM
28 /* Time in microseconds we delay before sleeping in the idle loop */
29 DEFINE_PER_CPU(unsigned long, smt_snooze_delay) = { 100 };
30 
31 static ssize_t store_smt_snooze_delay(struct sys_device *dev, const char *buf,
32 				      size_t count)
33 {
34 	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
35 	ssize_t ret;
36 	unsigned long snooze;
37 
38 	ret = sscanf(buf, "%lu", &snooze);
39 	if (ret != 1)
40 		return -EINVAL;
41 
42 	per_cpu(smt_snooze_delay, cpu->sysdev.id) = snooze;
43 
44 	return count;
45 }
46 
47 static ssize_t show_smt_snooze_delay(struct sys_device *dev, char *buf)
48 {
49 	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
50 
51 	return sprintf(buf, "%lu\n", per_cpu(smt_snooze_delay, cpu->sysdev.id));
52 }
53 
54 static SYSDEV_ATTR(smt_snooze_delay, 0644, show_smt_snooze_delay,
55 		   store_smt_snooze_delay);
56 
57 /* Only parse OF options if the matching cmdline option was not specified */
58 static int smt_snooze_cmdline;
59 
60 static int __init smt_setup(void)
61 {
62 	struct device_node *options;
63 	const unsigned int *val;
64 	unsigned int cpu;
65 
66 	if (!cpu_has_feature(CPU_FTR_SMT))
67 		return -ENODEV;
68 
69 	options = find_path_device("/options");
70 	if (!options)
71 		return -ENODEV;
72 
73 	val = get_property(options, "ibm,smt-snooze-delay", NULL);
74 	if (!smt_snooze_cmdline && val) {
75 		for_each_possible_cpu(cpu)
76 			per_cpu(smt_snooze_delay, cpu) = *val;
77 	}
78 
79 	return 0;
80 }
81 __initcall(smt_setup);
82 
83 static int __init setup_smt_snooze_delay(char *str)
84 {
85 	unsigned int cpu;
86 	int snooze;
87 
88 	if (!cpu_has_feature(CPU_FTR_SMT))
89 		return 1;
90 
91 	smt_snooze_cmdline = 1;
92 
93 	if (get_option(&str, &snooze)) {
94 		for_each_possible_cpu(cpu)
95 			per_cpu(smt_snooze_delay, cpu) = snooze;
96 	}
97 
98 	return 1;
99 }
100 __setup("smt-snooze-delay=", setup_smt_snooze_delay);
101 
102 #endif /* CONFIG_PPC_MULTIPLATFORM */
103 
104 /*
105  * Enabling PMCs will slow partition context switch times so we only do
106  * it the first time we write to the PMCs.
107  */
108 
109 static DEFINE_PER_CPU(char, pmcs_enabled);
110 
111 void ppc64_enable_pmcs(void)
112 {
113 	/* Only need to enable them once */
114 	if (__get_cpu_var(pmcs_enabled))
115 		return;
116 
117 	__get_cpu_var(pmcs_enabled) = 1;
118 
119 	if (ppc_md.enable_pmcs)
120 		ppc_md.enable_pmcs();
121 }
122 EXPORT_SYMBOL(ppc64_enable_pmcs);
123 
124 /* XXX convert to rusty's on_one_cpu */
125 static unsigned long run_on_cpu(unsigned long cpu,
126 			        unsigned long (*func)(unsigned long),
127 				unsigned long arg)
128 {
129 	cpumask_t old_affinity = current->cpus_allowed;
130 	unsigned long ret;
131 
132 	/* should return -EINVAL to userspace */
133 	if (set_cpus_allowed(current, cpumask_of_cpu(cpu)))
134 		return 0;
135 
136 	ret = func(arg);
137 
138 	set_cpus_allowed(current, old_affinity);
139 
140 	return ret;
141 }
142 
143 #define SYSFS_PMCSETUP(NAME, ADDRESS) \
144 static unsigned long read_##NAME(unsigned long junk) \
145 { \
146 	return mfspr(ADDRESS); \
147 } \
148 static unsigned long write_##NAME(unsigned long val) \
149 { \
150 	ppc64_enable_pmcs(); \
151 	mtspr(ADDRESS, val); \
152 	return 0; \
153 } \
154 static ssize_t show_##NAME(struct sys_device *dev, char *buf) \
155 { \
156 	struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
157 	unsigned long val = run_on_cpu(cpu->sysdev.id, read_##NAME, 0); \
158 	return sprintf(buf, "%lx\n", val); \
159 } \
160 static ssize_t __attribute_used__ \
161 	store_##NAME(struct sys_device *dev, const char *buf, size_t count) \
162 { \
163 	struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
164 	unsigned long val; \
165 	int ret = sscanf(buf, "%lx", &val); \
166 	if (ret != 1) \
167 		return -EINVAL; \
168 	run_on_cpu(cpu->sysdev.id, write_##NAME, val); \
169 	return count; \
170 }
171 
172 SYSFS_PMCSETUP(mmcr0, SPRN_MMCR0);
173 SYSFS_PMCSETUP(mmcr1, SPRN_MMCR1);
174 SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
175 SYSFS_PMCSETUP(pmc1, SPRN_PMC1);
176 SYSFS_PMCSETUP(pmc2, SPRN_PMC2);
177 SYSFS_PMCSETUP(pmc3, SPRN_PMC3);
178 SYSFS_PMCSETUP(pmc4, SPRN_PMC4);
179 SYSFS_PMCSETUP(pmc5, SPRN_PMC5);
180 SYSFS_PMCSETUP(pmc6, SPRN_PMC6);
181 SYSFS_PMCSETUP(pmc7, SPRN_PMC7);
182 SYSFS_PMCSETUP(pmc8, SPRN_PMC8);
183 SYSFS_PMCSETUP(purr, SPRN_PURR);
184 
185 static SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0);
186 static SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1);
187 static SYSDEV_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
188 static SYSDEV_ATTR(pmc1, 0600, show_pmc1, store_pmc1);
189 static SYSDEV_ATTR(pmc2, 0600, show_pmc2, store_pmc2);
190 static SYSDEV_ATTR(pmc3, 0600, show_pmc3, store_pmc3);
191 static SYSDEV_ATTR(pmc4, 0600, show_pmc4, store_pmc4);
192 static SYSDEV_ATTR(pmc5, 0600, show_pmc5, store_pmc5);
193 static SYSDEV_ATTR(pmc6, 0600, show_pmc6, store_pmc6);
194 static SYSDEV_ATTR(pmc7, 0600, show_pmc7, store_pmc7);
195 static SYSDEV_ATTR(pmc8, 0600, show_pmc8, store_pmc8);
196 static SYSDEV_ATTR(purr, 0600, show_purr, NULL);
197 
198 static void register_cpu_online(unsigned int cpu)
199 {
200 	struct cpu *c = &per_cpu(cpu_devices, cpu);
201 	struct sys_device *s = &c->sysdev;
202 
203 	if (!firmware_has_feature(FW_FEATURE_ISERIES) &&
204 			cpu_has_feature(CPU_FTR_SMT))
205 		sysdev_create_file(s, &attr_smt_snooze_delay);
206 
207 	/* PMC stuff */
208 
209 	sysdev_create_file(s, &attr_mmcr0);
210 	sysdev_create_file(s, &attr_mmcr1);
211 
212 	if (cpu_has_feature(CPU_FTR_MMCRA))
213 		sysdev_create_file(s, &attr_mmcra);
214 
215 	if (cur_cpu_spec->num_pmcs >= 1)
216 		sysdev_create_file(s, &attr_pmc1);
217 	if (cur_cpu_spec->num_pmcs >= 2)
218 		sysdev_create_file(s, &attr_pmc2);
219 	if (cur_cpu_spec->num_pmcs >= 3)
220 		sysdev_create_file(s, &attr_pmc3);
221 	if (cur_cpu_spec->num_pmcs >= 4)
222 		sysdev_create_file(s, &attr_pmc4);
223 	if (cur_cpu_spec->num_pmcs >= 5)
224 		sysdev_create_file(s, &attr_pmc5);
225 	if (cur_cpu_spec->num_pmcs >= 6)
226 		sysdev_create_file(s, &attr_pmc6);
227 	if (cur_cpu_spec->num_pmcs >= 7)
228 		sysdev_create_file(s, &attr_pmc7);
229 	if (cur_cpu_spec->num_pmcs >= 8)
230 		sysdev_create_file(s, &attr_pmc8);
231 
232 	if (cpu_has_feature(CPU_FTR_PURR))
233 		sysdev_create_file(s, &attr_purr);
234 }
235 
236 #ifdef CONFIG_HOTPLUG_CPU
237 static void unregister_cpu_online(unsigned int cpu)
238 {
239 	struct cpu *c = &per_cpu(cpu_devices, cpu);
240 	struct sys_device *s = &c->sysdev;
241 
242 	BUG_ON(!c->hotpluggable);
243 
244 	if (!firmware_has_feature(FW_FEATURE_ISERIES) &&
245 			cpu_has_feature(CPU_FTR_SMT))
246 		sysdev_remove_file(s, &attr_smt_snooze_delay);
247 
248 	/* PMC stuff */
249 
250 	sysdev_remove_file(s, &attr_mmcr0);
251 	sysdev_remove_file(s, &attr_mmcr1);
252 
253 	if (cpu_has_feature(CPU_FTR_MMCRA))
254 		sysdev_remove_file(s, &attr_mmcra);
255 
256 	if (cur_cpu_spec->num_pmcs >= 1)
257 		sysdev_remove_file(s, &attr_pmc1);
258 	if (cur_cpu_spec->num_pmcs >= 2)
259 		sysdev_remove_file(s, &attr_pmc2);
260 	if (cur_cpu_spec->num_pmcs >= 3)
261 		sysdev_remove_file(s, &attr_pmc3);
262 	if (cur_cpu_spec->num_pmcs >= 4)
263 		sysdev_remove_file(s, &attr_pmc4);
264 	if (cur_cpu_spec->num_pmcs >= 5)
265 		sysdev_remove_file(s, &attr_pmc5);
266 	if (cur_cpu_spec->num_pmcs >= 6)
267 		sysdev_remove_file(s, &attr_pmc6);
268 	if (cur_cpu_spec->num_pmcs >= 7)
269 		sysdev_remove_file(s, &attr_pmc7);
270 	if (cur_cpu_spec->num_pmcs >= 8)
271 		sysdev_remove_file(s, &attr_pmc8);
272 
273 	if (cpu_has_feature(CPU_FTR_PURR))
274 		sysdev_remove_file(s, &attr_purr);
275 }
276 #endif /* CONFIG_HOTPLUG_CPU */
277 
278 static int __cpuinit sysfs_cpu_notify(struct notifier_block *self,
279 				      unsigned long action, void *hcpu)
280 {
281 	unsigned int cpu = (unsigned int)(long)hcpu;
282 
283 	switch (action) {
284 	case CPU_ONLINE:
285 		register_cpu_online(cpu);
286 		break;
287 #ifdef CONFIG_HOTPLUG_CPU
288 	case CPU_DEAD:
289 		unregister_cpu_online(cpu);
290 		break;
291 #endif
292 	}
293 	return NOTIFY_OK;
294 }
295 
296 static struct notifier_block __cpuinitdata sysfs_cpu_nb = {
297 	.notifier_call	= sysfs_cpu_notify,
298 };
299 
300 static DEFINE_MUTEX(cpu_mutex);
301 
302 int cpu_add_sysdev_attr(struct sysdev_attribute *attr)
303 {
304 	int cpu;
305 
306 	mutex_lock(&cpu_mutex);
307 
308 	for_each_possible_cpu(cpu) {
309 		sysdev_create_file(get_cpu_sysdev(cpu), attr);
310 	}
311 
312 	mutex_unlock(&cpu_mutex);
313 	return 0;
314 }
315 EXPORT_SYMBOL_GPL(cpu_add_sysdev_attr);
316 
317 int cpu_add_sysdev_attr_group(struct attribute_group *attrs)
318 {
319 	int cpu;
320 	struct sys_device *sysdev;
321 
322 	mutex_lock(&cpu_mutex);
323 
324 	for_each_possible_cpu(cpu) {
325 		sysdev = get_cpu_sysdev(cpu);
326 		sysfs_create_group(&sysdev->kobj, attrs);
327 	}
328 
329 	mutex_unlock(&cpu_mutex);
330 	return 0;
331 }
332 EXPORT_SYMBOL_GPL(cpu_add_sysdev_attr_group);
333 
334 
335 void cpu_remove_sysdev_attr(struct sysdev_attribute *attr)
336 {
337 	int cpu;
338 
339 	mutex_lock(&cpu_mutex);
340 
341 	for_each_possible_cpu(cpu) {
342 		sysdev_remove_file(get_cpu_sysdev(cpu), attr);
343 	}
344 
345 	mutex_unlock(&cpu_mutex);
346 }
347 EXPORT_SYMBOL_GPL(cpu_remove_sysdev_attr);
348 
349 void cpu_remove_sysdev_attr_group(struct attribute_group *attrs)
350 {
351 	int cpu;
352 	struct sys_device *sysdev;
353 
354 	mutex_lock(&cpu_mutex);
355 
356 	for_each_possible_cpu(cpu) {
357 		sysdev = get_cpu_sysdev(cpu);
358 		sysfs_remove_group(&sysdev->kobj, attrs);
359 	}
360 
361 	mutex_unlock(&cpu_mutex);
362 }
363 EXPORT_SYMBOL_GPL(cpu_remove_sysdev_attr_group);
364 
365 
366 /* NUMA stuff */
367 
368 #ifdef CONFIG_NUMA
369 static void register_nodes(void)
370 {
371 	int i;
372 
373 	for (i = 0; i < MAX_NUMNODES; i++)
374 		register_one_node(i);
375 }
376 
377 int sysfs_add_device_to_node(struct sys_device *dev, int nid)
378 {
379 	struct node *node = &node_devices[nid];
380 	return sysfs_create_link(&node->sysdev.kobj, &dev->kobj,
381 			kobject_name(&dev->kobj));
382 }
383 
384 void sysfs_remove_device_from_node(struct sys_device *dev, int nid)
385 {
386 	struct node *node = &node_devices[nid];
387 	sysfs_remove_link(&node->sysdev.kobj, kobject_name(&dev->kobj));
388 }
389 
390 #else
391 static void register_nodes(void)
392 {
393 	return;
394 }
395 
396 #endif
397 
398 EXPORT_SYMBOL_GPL(sysfs_add_device_to_node);
399 EXPORT_SYMBOL_GPL(sysfs_remove_device_from_node);
400 
401 /* Only valid if CPU is present. */
402 static ssize_t show_physical_id(struct sys_device *dev, char *buf)
403 {
404 	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
405 
406 	return sprintf(buf, "%d\n", get_hard_smp_processor_id(cpu->sysdev.id));
407 }
408 static SYSDEV_ATTR(physical_id, 0444, show_physical_id, NULL);
409 
410 static int __init topology_init(void)
411 {
412 	int cpu;
413 
414 	register_nodes();
415 	register_cpu_notifier(&sysfs_cpu_nb);
416 
417 	for_each_possible_cpu(cpu) {
418 		struct cpu *c = &per_cpu(cpu_devices, cpu);
419 
420 		/*
421 		 * For now, we just see if the system supports making
422 		 * the RTAS calls for CPU hotplug.  But, there may be a
423 		 * more comprehensive way to do this for an individual
424 		 * CPU.  For instance, the boot cpu might never be valid
425 		 * for hotplugging.
426 		 */
427 		if (ppc_md.cpu_die)
428 			c->hotpluggable = 1;
429 
430 		if (cpu_online(cpu) || c->hotpluggable) {
431 			register_cpu(c, cpu);
432 
433 			sysdev_create_file(&c->sysdev, &attr_physical_id);
434 		}
435 
436 		if (cpu_online(cpu))
437 			register_cpu_online(cpu);
438 	}
439 
440 	return 0;
441 }
442 __initcall(topology_init);
443