xref: /openbmc/linux/arch/powerpc/kernel/sysfs.c (revision 64c70b1c)
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 = of_find_node_by_path("/options");
70 	if (!options)
71 		return -ENODEV;
72 
73 	val = of_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 	of_node_put(options);
80 	return 0;
81 }
82 __initcall(smt_setup);
83 
84 static int __init setup_smt_snooze_delay(char *str)
85 {
86 	unsigned int cpu;
87 	int snooze;
88 
89 	if (!cpu_has_feature(CPU_FTR_SMT))
90 		return 1;
91 
92 	smt_snooze_cmdline = 1;
93 
94 	if (get_option(&str, &snooze)) {
95 		for_each_possible_cpu(cpu)
96 			per_cpu(smt_snooze_delay, cpu) = snooze;
97 	}
98 
99 	return 1;
100 }
101 __setup("smt-snooze-delay=", setup_smt_snooze_delay);
102 
103 #endif /* CONFIG_PPC_MULTIPLATFORM */
104 
105 /*
106  * Enabling PMCs will slow partition context switch times so we only do
107  * it the first time we write to the PMCs.
108  */
109 
110 static DEFINE_PER_CPU(char, pmcs_enabled);
111 
112 void ppc64_enable_pmcs(void)
113 {
114 	/* Only need to enable them once */
115 	if (__get_cpu_var(pmcs_enabled))
116 		return;
117 
118 	__get_cpu_var(pmcs_enabled) = 1;
119 
120 	if (ppc_md.enable_pmcs)
121 		ppc_md.enable_pmcs();
122 }
123 EXPORT_SYMBOL(ppc64_enable_pmcs);
124 
125 /* XXX convert to rusty's on_one_cpu */
126 static unsigned long run_on_cpu(unsigned long cpu,
127 			        unsigned long (*func)(unsigned long),
128 				unsigned long arg)
129 {
130 	cpumask_t old_affinity = current->cpus_allowed;
131 	unsigned long ret;
132 
133 	/* should return -EINVAL to userspace */
134 	if (set_cpus_allowed(current, cpumask_of_cpu(cpu)))
135 		return 0;
136 
137 	ret = func(arg);
138 
139 	set_cpus_allowed(current, old_affinity);
140 
141 	return ret;
142 }
143 
144 #define SYSFS_PMCSETUP(NAME, ADDRESS) \
145 static unsigned long read_##NAME(unsigned long junk) \
146 { \
147 	return mfspr(ADDRESS); \
148 } \
149 static unsigned long write_##NAME(unsigned long val) \
150 { \
151 	ppc64_enable_pmcs(); \
152 	mtspr(ADDRESS, val); \
153 	return 0; \
154 } \
155 static ssize_t show_##NAME(struct sys_device *dev, char *buf) \
156 { \
157 	struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
158 	unsigned long val = run_on_cpu(cpu->sysdev.id, read_##NAME, 0); \
159 	return sprintf(buf, "%lx\n", val); \
160 } \
161 static ssize_t __attribute_used__ \
162 	store_##NAME(struct sys_device *dev, const char *buf, size_t count) \
163 { \
164 	struct cpu *cpu = container_of(dev, struct cpu, sysdev); \
165 	unsigned long val; \
166 	int ret = sscanf(buf, "%lx", &val); \
167 	if (ret != 1) \
168 		return -EINVAL; \
169 	run_on_cpu(cpu->sysdev.id, write_##NAME, val); \
170 	return count; \
171 }
172 
173 
174 /* Let's define all possible registers, we'll only hook up the ones
175  * that are implemented on the current processor
176  */
177 
178 SYSFS_PMCSETUP(mmcr0, SPRN_MMCR0);
179 SYSFS_PMCSETUP(mmcr1, SPRN_MMCR1);
180 SYSFS_PMCSETUP(mmcra, SPRN_MMCRA);
181 SYSFS_PMCSETUP(pmc1, SPRN_PMC1);
182 SYSFS_PMCSETUP(pmc2, SPRN_PMC2);
183 SYSFS_PMCSETUP(pmc3, SPRN_PMC3);
184 SYSFS_PMCSETUP(pmc4, SPRN_PMC4);
185 SYSFS_PMCSETUP(pmc5, SPRN_PMC5);
186 SYSFS_PMCSETUP(pmc6, SPRN_PMC6);
187 SYSFS_PMCSETUP(pmc7, SPRN_PMC7);
188 SYSFS_PMCSETUP(pmc8, SPRN_PMC8);
189 SYSFS_PMCSETUP(purr, SPRN_PURR);
190 SYSFS_PMCSETUP(spurr, SPRN_SPURR);
191 SYSFS_PMCSETUP(dscr, SPRN_DSCR);
192 
193 SYSFS_PMCSETUP(pa6t_pmc0, SPRN_PA6T_PMC0);
194 SYSFS_PMCSETUP(pa6t_pmc1, SPRN_PA6T_PMC1);
195 SYSFS_PMCSETUP(pa6t_pmc2, SPRN_PA6T_PMC2);
196 SYSFS_PMCSETUP(pa6t_pmc3, SPRN_PA6T_PMC3);
197 SYSFS_PMCSETUP(pa6t_pmc4, SPRN_PA6T_PMC4);
198 SYSFS_PMCSETUP(pa6t_pmc5, SPRN_PA6T_PMC5);
199 
200 
201 static SYSDEV_ATTR(mmcra, 0600, show_mmcra, store_mmcra);
202 static SYSDEV_ATTR(spurr, 0600, show_spurr, NULL);
203 static SYSDEV_ATTR(dscr, 0600, show_dscr, store_dscr);
204 static SYSDEV_ATTR(purr, 0600, show_purr, store_purr);
205 
206 static struct sysdev_attribute ibm_common_attrs[] = {
207 	_SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
208 	_SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
209 };
210 
211 static struct sysdev_attribute ibm_pmc_attrs[] = {
212 	_SYSDEV_ATTR(pmc1, 0600, show_pmc1, store_pmc1),
213 	_SYSDEV_ATTR(pmc2, 0600, show_pmc2, store_pmc2),
214 	_SYSDEV_ATTR(pmc3, 0600, show_pmc3, store_pmc3),
215 	_SYSDEV_ATTR(pmc4, 0600, show_pmc4, store_pmc4),
216 	_SYSDEV_ATTR(pmc5, 0600, show_pmc5, store_pmc5),
217 	_SYSDEV_ATTR(pmc6, 0600, show_pmc6, store_pmc6),
218 	_SYSDEV_ATTR(pmc7, 0600, show_pmc7, store_pmc7),
219 	_SYSDEV_ATTR(pmc8, 0600, show_pmc8, store_pmc8),
220 };
221 
222 static struct sysdev_attribute pa6t_attrs[] = {
223 	_SYSDEV_ATTR(mmcr0, 0600, show_mmcr0, store_mmcr0),
224 	_SYSDEV_ATTR(mmcr1, 0600, show_mmcr1, store_mmcr1),
225 	_SYSDEV_ATTR(pmc0, 0600, show_pa6t_pmc0, store_pa6t_pmc0),
226 	_SYSDEV_ATTR(pmc1, 0600, show_pa6t_pmc1, store_pa6t_pmc1),
227 	_SYSDEV_ATTR(pmc2, 0600, show_pa6t_pmc2, store_pa6t_pmc2),
228 	_SYSDEV_ATTR(pmc3, 0600, show_pa6t_pmc3, store_pa6t_pmc3),
229 	_SYSDEV_ATTR(pmc4, 0600, show_pa6t_pmc4, store_pa6t_pmc4),
230 	_SYSDEV_ATTR(pmc5, 0600, show_pa6t_pmc5, store_pa6t_pmc5),
231 };
232 
233 
234 static void register_cpu_online(unsigned int cpu)
235 {
236 	struct cpu *c = &per_cpu(cpu_devices, cpu);
237 	struct sys_device *s = &c->sysdev;
238 	struct sysdev_attribute *attrs, *pmc_attrs;
239 	int i, nattrs;
240 
241 	if (!firmware_has_feature(FW_FEATURE_ISERIES) &&
242 			cpu_has_feature(CPU_FTR_SMT))
243 		sysdev_create_file(s, &attr_smt_snooze_delay);
244 
245 	/* PMC stuff */
246 	switch (cur_cpu_spec->pmc_type) {
247 	case PPC_PMC_IBM:
248 		attrs = ibm_common_attrs;
249 		nattrs = sizeof(ibm_common_attrs) / sizeof(struct sysdev_attribute);
250 		pmc_attrs = ibm_pmc_attrs;
251 		break;
252 	case PPC_PMC_PA6T:
253 		/* PA Semi starts counting at PMC0 */
254 		attrs = pa6t_attrs;
255 		nattrs = sizeof(pa6t_attrs) / sizeof(struct sysdev_attribute);
256 		pmc_attrs = NULL;
257 		break;
258 	default:
259 		attrs = NULL;
260 		nattrs = 0;
261 		pmc_attrs = NULL;
262 	}
263 
264 	for (i = 0; i < nattrs; i++)
265 		sysdev_create_file(s, &attrs[i]);
266 
267 	if (pmc_attrs)
268 		for (i = 0; i < cur_cpu_spec->num_pmcs; i++)
269 			sysdev_create_file(s, &pmc_attrs[i]);
270 
271 	if (cpu_has_feature(CPU_FTR_MMCRA))
272 		sysdev_create_file(s, &attr_mmcra);
273 
274 	if (cpu_has_feature(CPU_FTR_PURR))
275 		sysdev_create_file(s, &attr_purr);
276 
277 	if (cpu_has_feature(CPU_FTR_SPURR))
278 		sysdev_create_file(s, &attr_spurr);
279 
280 	if (cpu_has_feature(CPU_FTR_DSCR))
281 		sysdev_create_file(s, &attr_dscr);
282 }
283 
284 #ifdef CONFIG_HOTPLUG_CPU
285 static void unregister_cpu_online(unsigned int cpu)
286 {
287 	struct cpu *c = &per_cpu(cpu_devices, cpu);
288 	struct sys_device *s = &c->sysdev;
289 	struct sysdev_attribute *attrs, *pmc_attrs;
290 	int i, nattrs;
291 
292 	BUG_ON(!c->hotpluggable);
293 
294 	if (!firmware_has_feature(FW_FEATURE_ISERIES) &&
295 			cpu_has_feature(CPU_FTR_SMT))
296 		sysdev_remove_file(s, &attr_smt_snooze_delay);
297 
298 	/* PMC stuff */
299 	switch (cur_cpu_spec->pmc_type) {
300 	case PPC_PMC_IBM:
301 		attrs = ibm_common_attrs;
302 		nattrs = sizeof(ibm_common_attrs) / sizeof(struct sysdev_attribute);
303 		pmc_attrs = ibm_pmc_attrs;
304 		break;
305 	case PPC_PMC_PA6T:
306 		/* PA Semi starts counting at PMC0 */
307 		attrs = pa6t_attrs;
308 		nattrs = sizeof(pa6t_attrs) / sizeof(struct sysdev_attribute);
309 		pmc_attrs = NULL;
310 		break;
311 	default:
312 		attrs = NULL;
313 		nattrs = 0;
314 		pmc_attrs = NULL;
315 	}
316 
317 	for (i = 0; i < nattrs; i++)
318 		sysdev_remove_file(s, &attrs[i]);
319 
320 	if (pmc_attrs)
321 		for (i = 0; i < cur_cpu_spec->num_pmcs; i++)
322 			sysdev_remove_file(s, &pmc_attrs[i]);
323 
324 	if (cpu_has_feature(CPU_FTR_MMCRA))
325 		sysdev_remove_file(s, &attr_mmcra);
326 
327 	if (cpu_has_feature(CPU_FTR_PURR))
328 		sysdev_remove_file(s, &attr_purr);
329 
330 	if (cpu_has_feature(CPU_FTR_SPURR))
331 		sysdev_remove_file(s, &attr_spurr);
332 
333 	if (cpu_has_feature(CPU_FTR_DSCR))
334 		sysdev_remove_file(s, &attr_dscr);
335 }
336 #endif /* CONFIG_HOTPLUG_CPU */
337 
338 static int __cpuinit sysfs_cpu_notify(struct notifier_block *self,
339 				      unsigned long action, void *hcpu)
340 {
341 	unsigned int cpu = (unsigned int)(long)hcpu;
342 
343 	switch (action) {
344 	case CPU_ONLINE:
345 	case CPU_ONLINE_FROZEN:
346 		register_cpu_online(cpu);
347 		break;
348 #ifdef CONFIG_HOTPLUG_CPU
349 	case CPU_DEAD:
350 	case CPU_DEAD_FROZEN:
351 		unregister_cpu_online(cpu);
352 		break;
353 #endif
354 	}
355 	return NOTIFY_OK;
356 }
357 
358 static struct notifier_block __cpuinitdata sysfs_cpu_nb = {
359 	.notifier_call	= sysfs_cpu_notify,
360 };
361 
362 static DEFINE_MUTEX(cpu_mutex);
363 
364 int cpu_add_sysdev_attr(struct sysdev_attribute *attr)
365 {
366 	int cpu;
367 
368 	mutex_lock(&cpu_mutex);
369 
370 	for_each_possible_cpu(cpu) {
371 		sysdev_create_file(get_cpu_sysdev(cpu), attr);
372 	}
373 
374 	mutex_unlock(&cpu_mutex);
375 	return 0;
376 }
377 EXPORT_SYMBOL_GPL(cpu_add_sysdev_attr);
378 
379 int cpu_add_sysdev_attr_group(struct attribute_group *attrs)
380 {
381 	int cpu;
382 	struct sys_device *sysdev;
383 
384 	mutex_lock(&cpu_mutex);
385 
386 	for_each_possible_cpu(cpu) {
387 		sysdev = get_cpu_sysdev(cpu);
388 		sysfs_create_group(&sysdev->kobj, attrs);
389 	}
390 
391 	mutex_unlock(&cpu_mutex);
392 	return 0;
393 }
394 EXPORT_SYMBOL_GPL(cpu_add_sysdev_attr_group);
395 
396 
397 void cpu_remove_sysdev_attr(struct sysdev_attribute *attr)
398 {
399 	int cpu;
400 
401 	mutex_lock(&cpu_mutex);
402 
403 	for_each_possible_cpu(cpu) {
404 		sysdev_remove_file(get_cpu_sysdev(cpu), attr);
405 	}
406 
407 	mutex_unlock(&cpu_mutex);
408 }
409 EXPORT_SYMBOL_GPL(cpu_remove_sysdev_attr);
410 
411 void cpu_remove_sysdev_attr_group(struct attribute_group *attrs)
412 {
413 	int cpu;
414 	struct sys_device *sysdev;
415 
416 	mutex_lock(&cpu_mutex);
417 
418 	for_each_possible_cpu(cpu) {
419 		sysdev = get_cpu_sysdev(cpu);
420 		sysfs_remove_group(&sysdev->kobj, attrs);
421 	}
422 
423 	mutex_unlock(&cpu_mutex);
424 }
425 EXPORT_SYMBOL_GPL(cpu_remove_sysdev_attr_group);
426 
427 
428 /* NUMA stuff */
429 
430 #ifdef CONFIG_NUMA
431 static void register_nodes(void)
432 {
433 	int i;
434 
435 	for (i = 0; i < MAX_NUMNODES; i++)
436 		register_one_node(i);
437 }
438 
439 int sysfs_add_device_to_node(struct sys_device *dev, int nid)
440 {
441 	struct node *node = &node_devices[nid];
442 	return sysfs_create_link(&node->sysdev.kobj, &dev->kobj,
443 			kobject_name(&dev->kobj));
444 }
445 
446 void sysfs_remove_device_from_node(struct sys_device *dev, int nid)
447 {
448 	struct node *node = &node_devices[nid];
449 	sysfs_remove_link(&node->sysdev.kobj, kobject_name(&dev->kobj));
450 }
451 
452 #else
453 static void register_nodes(void)
454 {
455 	return;
456 }
457 
458 #endif
459 
460 EXPORT_SYMBOL_GPL(sysfs_add_device_to_node);
461 EXPORT_SYMBOL_GPL(sysfs_remove_device_from_node);
462 
463 /* Only valid if CPU is present. */
464 static ssize_t show_physical_id(struct sys_device *dev, char *buf)
465 {
466 	struct cpu *cpu = container_of(dev, struct cpu, sysdev);
467 
468 	return sprintf(buf, "%d\n", get_hard_smp_processor_id(cpu->sysdev.id));
469 }
470 static SYSDEV_ATTR(physical_id, 0444, show_physical_id, NULL);
471 
472 static int __init topology_init(void)
473 {
474 	int cpu;
475 
476 	register_nodes();
477 	register_cpu_notifier(&sysfs_cpu_nb);
478 
479 	for_each_possible_cpu(cpu) {
480 		struct cpu *c = &per_cpu(cpu_devices, cpu);
481 
482 		/*
483 		 * For now, we just see if the system supports making
484 		 * the RTAS calls for CPU hotplug.  But, there may be a
485 		 * more comprehensive way to do this for an individual
486 		 * CPU.  For instance, the boot cpu might never be valid
487 		 * for hotplugging.
488 		 */
489 		if (ppc_md.cpu_die)
490 			c->hotpluggable = 1;
491 
492 		if (cpu_online(cpu) || c->hotpluggable) {
493 			register_cpu(c, cpu);
494 
495 			sysdev_create_file(&c->sysdev, &attr_physical_id);
496 		}
497 
498 		if (cpu_online(cpu))
499 			register_cpu_online(cpu);
500 	}
501 
502 	return 0;
503 }
504 subsys_initcall(topology_init);
505