2 * Copyright IBM Corp. 2007,2011
3 * Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
6 #define KMSG_COMPONENT "cpu"
7 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
9 #include <linux/workqueue.h>
10 #include <linux/bootmem.h>
11 #include <linux/cpuset.h>
12 #include <linux/device.h>
13 #include <linux/kernel.h>
14 #include <linux/sched.h>
15 #include <linux/init.h>
16 #include <linux/delay.h>
17 #include <linux/cpu.h>
18 #include <linux/smp.h>
21 #define PTF_HORIZONTAL (0UL)
22 #define PTF_VERTICAL (1UL)
23 #define PTF_CHECK (2UL)
26 struct mask_info *next;
31 static int topology_enabled = 1;
32 static void topology_work_fn(struct work_struct *work);
33 static struct sysinfo_15_1_x *tl_info;
34 static void set_topology_timer(void);
35 static DECLARE_WORK(topology_work, topology_work_fn);
36 /* topology_lock protects the core linked list */
37 static DEFINE_SPINLOCK(topology_lock);
39 static struct mask_info core_info;
40 cpumask_t cpu_core_map[NR_CPUS];
41 unsigned char cpu_core_id[NR_CPUS];
43 static struct mask_info book_info;
44 cpumask_t cpu_book_map[NR_CPUS];
45 unsigned char cpu_book_id[NR_CPUS];
47 /* smp_cpu_state_mutex must be held when accessing this array */
48 int cpu_polarization[NR_CPUS];
50 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
55 if (!topology_enabled || !MACHINE_HAS_TOPOLOGY) {
56 cpumask_copy(&mask, cpumask_of(cpu));
60 if (cpumask_test_cpu(cpu, &info->mask)) {
66 if (cpumask_empty(&mask))
67 cpumask_copy(&mask, cpumask_of(cpu));
71 static struct mask_info *add_cpus_to_mask(struct topology_cpu *tl_cpu,
72 struct mask_info *book,
73 struct mask_info *core,
78 for (cpu = find_first_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS);
79 cpu < TOPOLOGY_CPU_BITS;
80 cpu = find_next_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS, cpu + 1))
82 unsigned int rcpu, lcpu;
84 rcpu = TOPOLOGY_CPU_BITS - 1 - cpu + tl_cpu->origin;
85 for_each_present_cpu(lcpu) {
86 if (cpu_logical_map(lcpu) != rcpu)
88 cpumask_set_cpu(lcpu, &book->mask);
89 cpu_book_id[lcpu] = book->id;
90 cpumask_set_cpu(lcpu, &core->mask);
91 if (one_core_per_cpu) {
92 cpu_core_id[lcpu] = rcpu;
95 cpu_core_id[lcpu] = core->id;
97 cpu_set_polarization(lcpu, tl_cpu->pp);
103 static void clear_masks(void)
105 struct mask_info *info;
109 cpumask_clear(&info->mask);
114 cpumask_clear(&info->mask);
119 static union topology_entry *next_tle(union topology_entry *tle)
122 return (union topology_entry *)((struct topology_cpu *)tle + 1);
123 return (union topology_entry *)((struct topology_container *)tle + 1);
126 static void __tl_to_cores_generic(struct sysinfo_15_1_x *info)
128 struct mask_info *core = &core_info;
129 struct mask_info *book = &book_info;
130 union topology_entry *tle, *end;
133 end = (union topology_entry *)((unsigned long)info + info->length);
138 book->id = tle->container.id;
142 core->id = tle->container.id;
145 add_cpus_to_mask(&tle->cpu, book, core, 0);
155 static void __tl_to_cores_z10(struct sysinfo_15_1_x *info)
157 struct mask_info *core = &core_info;
158 struct mask_info *book = &book_info;
159 union topology_entry *tle, *end;
162 end = (union topology_entry *)((unsigned long)info + info->length);
167 book->id = tle->container.id;
170 core = add_cpus_to_mask(&tle->cpu, book, core, 1);
180 static void tl_to_cores(struct sysinfo_15_1_x *info)
185 spin_lock_irq(&topology_lock);
187 switch (cpu_id.machine) {
190 __tl_to_cores_z10(info);
193 __tl_to_cores_generic(info);
195 spin_unlock_irq(&topology_lock);
198 static void topology_update_polarization_simple(void)
202 mutex_lock(&smp_cpu_state_mutex);
203 for_each_possible_cpu(cpu)
204 cpu_set_polarization(cpu, POLARIZATION_HRZ);
205 mutex_unlock(&smp_cpu_state_mutex);
208 static int ptf(unsigned long fc)
213 " .insn rre,0xb9a20000,%1,%1\n"
221 int topology_set_cpu_management(int fc)
225 if (!MACHINE_HAS_TOPOLOGY)
228 rc = ptf(PTF_VERTICAL);
230 rc = ptf(PTF_HORIZONTAL);
233 for_each_possible_cpu(cpu)
234 cpu_set_polarization(cpu, POLARIZATION_UNKNOWN);
238 static void update_cpu_core_map(void)
243 spin_lock_irqsave(&topology_lock, flags);
244 for_each_possible_cpu(cpu) {
245 cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
246 cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
248 spin_unlock_irqrestore(&topology_lock, flags);
251 void store_topology(struct sysinfo_15_1_x *info)
255 rc = stsi(info, 15, 1, 3);
258 stsi(info, 15, 1, 2);
261 int arch_update_cpu_topology(void)
263 struct sysinfo_15_1_x *info = tl_info;
267 if (!MACHINE_HAS_TOPOLOGY) {
268 update_cpu_core_map();
269 topology_update_polarization_simple();
272 store_topology(info);
274 update_cpu_core_map();
275 for_each_online_cpu(cpu) {
276 dev = get_cpu_device(cpu);
277 kobject_uevent(&dev->kobj, KOBJ_CHANGE);
282 static void topology_work_fn(struct work_struct *work)
284 rebuild_sched_domains();
287 void topology_schedule_update(void)
289 schedule_work(&topology_work);
292 static void topology_timer_fn(unsigned long ignored)
295 topology_schedule_update();
296 set_topology_timer();
299 static struct timer_list topology_timer =
300 TIMER_DEFERRED_INITIALIZER(topology_timer_fn, 0, 0);
302 static atomic_t topology_poll = ATOMIC_INIT(0);
304 static void set_topology_timer(void)
306 if (atomic_add_unless(&topology_poll, -1, 0))
307 mod_timer(&topology_timer, jiffies + HZ / 10);
309 mod_timer(&topology_timer, jiffies + HZ * 60);
312 void topology_expect_change(void)
314 if (!MACHINE_HAS_TOPOLOGY)
316 /* This is racy, but it doesn't matter since it is just a heuristic.
317 * Worst case is that we poll in a higher frequency for a bit longer.
319 if (atomic_read(&topology_poll) > 60)
321 atomic_add(60, &topology_poll);
322 set_topology_timer();
325 static int __init early_parse_topology(char *p)
327 if (strncmp(p, "off", 3))
329 topology_enabled = 0;
332 early_param("topology", early_parse_topology);
334 static void __init alloc_masks(struct sysinfo_15_1_x *info,
335 struct mask_info *mask, int offset)
339 nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
340 for (i = 0; i < info->mnest - offset; i++)
341 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
342 nr_masks = max(nr_masks, 1);
343 for (i = 0; i < nr_masks; i++) {
344 mask->next = alloc_bootmem(sizeof(struct mask_info));
349 void __init s390_init_cpu_topology(void)
351 struct sysinfo_15_1_x *info;
354 if (!MACHINE_HAS_TOPOLOGY)
356 tl_info = alloc_bootmem_pages(PAGE_SIZE);
358 store_topology(info);
359 pr_info("The CPU configuration topology of the machine is:");
360 for (i = 0; i < TOPOLOGY_NR_MAG; i++)
361 printk(KERN_CONT " %d", info->mag[i]);
362 printk(KERN_CONT " / %d\n", info->mnest);
363 alloc_masks(info, &core_info, 1);
364 alloc_masks(info, &book_info, 2);
367 static int cpu_management;
369 static ssize_t dispatching_show(struct device *dev,
370 struct device_attribute *attr,
375 mutex_lock(&smp_cpu_state_mutex);
376 count = sprintf(buf, "%d\n", cpu_management);
377 mutex_unlock(&smp_cpu_state_mutex);
381 static ssize_t dispatching_store(struct device *dev,
382 struct device_attribute *attr,
389 if (sscanf(buf, "%d %c", &val, &delim) != 1)
391 if (val != 0 && val != 1)
395 mutex_lock(&smp_cpu_state_mutex);
396 if (cpu_management == val)
398 rc = topology_set_cpu_management(val);
401 cpu_management = val;
402 topology_expect_change();
404 mutex_unlock(&smp_cpu_state_mutex);
406 return rc ? rc : count;
408 static DEVICE_ATTR(dispatching, 0644, dispatching_show,
411 static ssize_t cpu_polarization_show(struct device *dev,
412 struct device_attribute *attr, char *buf)
417 mutex_lock(&smp_cpu_state_mutex);
418 switch (cpu_read_polarization(cpu)) {
419 case POLARIZATION_HRZ:
420 count = sprintf(buf, "horizontal\n");
422 case POLARIZATION_VL:
423 count = sprintf(buf, "vertical:low\n");
425 case POLARIZATION_VM:
426 count = sprintf(buf, "vertical:medium\n");
428 case POLARIZATION_VH:
429 count = sprintf(buf, "vertical:high\n");
432 count = sprintf(buf, "unknown\n");
435 mutex_unlock(&smp_cpu_state_mutex);
438 static DEVICE_ATTR(polarization, 0444, cpu_polarization_show, NULL);
440 static struct attribute *topology_cpu_attrs[] = {
441 &dev_attr_polarization.attr,
445 static struct attribute_group topology_cpu_attr_group = {
446 .attrs = topology_cpu_attrs,
449 int topology_cpu_init(struct cpu *cpu)
451 return sysfs_create_group(&cpu->dev.kobj, &topology_cpu_attr_group);
454 static int __init topology_init(void)
456 if (!MACHINE_HAS_TOPOLOGY) {
457 topology_update_polarization_simple();
460 set_topology_timer();
462 update_cpu_core_map();
463 return device_create_file(cpu_subsys.dev_root, &dev_attr_dispatching);
465 device_initcall(topology_init);