summaryrefslogtreecommitdiffstats
path: root/arch/s390/kernel/topology.c
blob: 13559c9938470b9d7d0c2597f6418e518d865c78 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
/*
 *    Copyright IBM Corp. 2007
 *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
 */

#define KMSG_COMPONENT "cpu"
#define pr_fmt(fmt) KMSG_COMPONENT ": " fmt

#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/init.h>
#include <linux/device.h>
#include <linux/bootmem.h>
#include <linux/sched.h>
#include <linux/workqueue.h>
#include <linux/cpu.h>
#include <linux/smp.h>
#include <linux/cpuset.h>
#include <asm/delay.h>
#include <asm/s390_ext.h>
#include <asm/sysinfo.h>

#define CPU_BITS 64
#define NR_MAG 6

#define PTF_HORIZONTAL	(0UL)
#define PTF_VERTICAL	(1UL)
#define PTF_CHECK	(2UL)

struct tl_cpu {
	unsigned char reserved0[4];
	unsigned char :6;
	unsigned char pp:2;
	unsigned char reserved1;
	unsigned short origin;
	unsigned long mask[CPU_BITS / BITS_PER_LONG];
};

struct tl_container {
	unsigned char reserved[7];
	unsigned char id;
};

union tl_entry {
	unsigned char nl;
	struct tl_cpu cpu;
	struct tl_container container;
};

struct tl_info {
	unsigned char reserved0[2];
	unsigned short length;
	unsigned char mag[NR_MAG];
	unsigned char reserved1;
	unsigned char mnest;
	unsigned char reserved2[4];
	union tl_entry tle[0];
};

struct mask_info {
	struct mask_info *next;
	unsigned char id;
	cpumask_t mask;
};

static int topology_enabled;
static void topology_work_fn(struct work_struct *work);
static struct tl_info *tl_info;
static int machine_has_topology;
static struct timer_list topology_timer;
static void set_topology_timer(void);
static DECLARE_WORK(topology_work, topology_work_fn);
/* topology_lock protects the core linked list */
static DEFINE_SPINLOCK(topology_lock);

static struct mask_info core_info;
cpumask_t cpu_core_map[NR_CPUS];
unsigned char cpu_core_id[NR_CPUS];

#ifdef CONFIG_SCHED_BOOK
static struct mask_info book_info;
cpumask_t cpu_book_map[NR_CPUS];
unsigned char cpu_book_id[NR_CPUS];
#endif

static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
{
	cpumask_t mask;

	cpus_clear(mask);
	if (!topology_enabled || !machine_has_topology)
		return cpu_possible_map;
	while (info) {
		if (cpu_isset(cpu, info->mask)) {
			mask = info->mask;
			break;
		}
		info = info->next;
	}
	if (cpus_empty(mask))
		mask = cpumask_of_cpu(cpu);
	return mask;
}

static void add_cpus_to_mask(struct tl_cpu *tl_cpu, struct mask_info *book,
			     struct mask_info *core)
{
	unsigned int cpu;

	for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
	     cpu < CPU_BITS;
	     cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
	{
		unsigned int rcpu, lcpu;

		rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
		for_each_present_cpu(lcpu) {
			if (cpu_logical_map(lcpu) != rcpu)
				continue;
#ifdef CONFIG_SCHED_BOOK
			cpu_set(lcpu, book->mask);
			cpu_book_id[lcpu] = book->id;
#endif
			cpu_set(lcpu, core->mask);
			cpu_core_id[lcpu] = core->id;
			smp_cpu_polarization[lcpu] = tl_cpu->pp;
		}
	}
}

static void clear_masks(void)
{
	struct mask_info *info;

	info = &core_info;
	while (info) {
		cpus_clear(info->mask);
		info = info->next;
	}
#ifdef CONFIG_SCHED_BOOK
	info = &book_info;
	while (info) {
		cpus_clear(info->mask);
		info = info->next;
	}
#endif
}

static union tl_entry *next_tle(union tl_entry *tle)
{
	if (tle->nl)
		return (union tl_entry *)((struct tl_container *)tle + 1);
	else
		return (union tl_entry *)((struct tl_cpu *)tle + 1);
}

static void tl_to_cores(struct tl_info *info)
{
#ifdef CONFIG_SCHED_BOOK
	struct mask_info *book = &book_info;
#else
	struct mask_info *book = NULL;
#endif
	struct mask_info *core = &core_info;
	union tl_entry *tle, *end;


	spin_lock_irq(&topology_lock);
	clear_masks();
	tle = info->tle;
	end = (union tl_entry *)((unsigned long)info + info->length);
	while (tle < end) {
		switch (tle->nl) {
#ifdef CONFIG_SCHED_BOOK
		case 2:
			book = book->next;
			book->id = tle->container.id;
			break;
#endif
		case 1:
			core = core->next;
			core->id = tle->container.id;
			break;
		case 0:
			add_cpus_to_mask(&tle->cpu, book, core);
			break;
		default:
			clear_masks();
			machine_has_topology = 0;
			goto out;
		}
		tle = next_tle(tle);
	}
out:
	spin_unlock_irq(&topology_lock);
}

static void topology_update_polarization_simple(void)
{
	int cpu;

	mutex_lock(&smp_cpu_state_mutex);
	for_each_possible_cpu(cpu)
		smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
	mutex_unlock(&smp_cpu_state_mutex);
}

static int ptf(unsigned long fc)
{
	int rc;

	asm volatile(
		"	.insn	rre,0xb9a20000,%1,%1\n"
		"	ipm	%0\n"
		"	srl	%0,28\n"
		: "=d" (rc)
		: "d" (fc)  : "cc");
	return rc;
}

int topology_set_cpu_management(int fc)
{
	int cpu;
	int rc;

	if (!machine_has_topology)
		return -EOPNOTSUPP;
	if (fc)
		rc = ptf(PTF_VERTICAL);
	else
		rc = ptf(PTF_HORIZONTAL);
	if (rc)
		return -EBUSY;
	for_each_possible_cpu(cpu)
		smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
	return rc;
}

static void update_cpu_core_map(void)
{
	unsigned long flags;
	int cpu;

	spin_lock_irqsave(&topology_lock, flags);
	for_each_possible_cpu(cpu) {
		cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
#ifdef CONFIG_SCHED_BOOK
		cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
#endif
	}
	spin_unlock_irqrestore(&topology_lock, flags);
}

static void store_topology(struct tl_info *info)
{
#ifdef CONFIG_SCHED_BOOK
	int rc;

	rc = stsi(info, 15, 1, 3);
	if (rc != -ENOSYS)
		return;
#endif
	stsi(info, 15, 1, 2);
}

int arch_update_cpu_topology(void)
{
	struct tl_info *info = tl_info;
	struct sys_device *sysdev;
	int cpu;

	if (!machine_has_topology) {
		update_cpu_core_map();
		topology_update_polarization_simple();
		return 0;
	}
	store_topology(info);
	tl_to_cores(info);
	update_cpu_core_map();
	for_each_online_cpu(cpu) {
		sysdev = get_cpu_sysdev(cpu);
		kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
	}
	return 1;
}

static void topology_work_fn(struct work_struct *work)
{
	rebuild_sched_domains();
}

void topology_schedule_update(void)
{
	schedule_work(&topology_work);
}

static void topology_timer_fn(unsigned long ignored)
{
	if (ptf(PTF_CHECK))
		topology_schedule_update();
	set_topology_timer();
}

static void set_topology_timer(void)
{
	topology_timer.function = topology_timer_fn;
	topology_timer.data = 0;
	topology_timer.expires = jiffies + 60 * HZ;
	add_timer(&topology_timer);
}

static int __init early_parse_topology(char *p)
{
	if (strncmp(p, "on", 2))
		return 0;
	topology_enabled = 1;
	return 0;
}
early_param("topology", early_parse_topology);

static int __init init_topology_update(void)
{
	int rc;

	rc = 0;
	if (!machine_has_topology) {
		topology_update_polarization_simple();
		goto out;
	}
	init_timer_deferrable(&topology_timer);
	set_topology_timer();
out:
	update_cpu_core_map();
	return rc;
}
__initcall(init_topology_update);

static void alloc_masks(struct tl_info *info, struct mask_info *mask, int offset)
{
	int i, nr_masks;

	nr_masks = info->mag[NR_MAG - offset];
	for (i = 0; i < info->mnest - offset; i++)
		nr_masks *= info->mag[NR_MAG - offset - 1 - i];
	nr_masks = max(nr_masks, 1);
	for (i = 0; i < nr_masks; i++) {
		mask->next = alloc_bootmem(sizeof(struct mask_info));
		mask = mask->next;
	}
}

void __init s390_init_cpu_topology(void)
{
	unsigned long long facility_bits;
	struct tl_info *info;
	int i;

	if (stfle(&facility_bits, 1) <= 0)
		return;
	if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
		return;
	machine_has_topology = 1;

	tl_info = alloc_bootmem_pages(PAGE_SIZE);
	info = tl_info;
	store_topology(info);
	pr_info("The CPU configuration topology of the machine is:");
	for (i = 0; i < NR_MAG; i++)
		printk(" %d", info->mag[i]);
	printk(" / %d\n", info->mnest);
	alloc_masks(info, &core_info, 2);
#ifdef CONFIG_SCHED_BOOK
	alloc_masks(info, &book_info, 3);
#endif
}