xref: /linux/arch/s390/kernel/topology.c (revision 171f1bc77c2d34308392841bcffa69b8a22c2e09)
1 /*
2  *    Copyright IBM Corp. 2007
3  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
4  */
5 
6 #define KMSG_COMPONENT "cpu"
7 #define pr_fmt(fmt) KMSG_COMPONENT ": " fmt
8 
9 #include <linux/kernel.h>
10 #include <linux/mm.h>
11 #include <linux/init.h>
12 #include <linux/device.h>
13 #include <linux/bootmem.h>
14 #include <linux/sched.h>
15 #include <linux/workqueue.h>
16 #include <linux/cpu.h>
17 #include <linux/smp.h>
18 #include <linux/cpuset.h>
19 #include <asm/delay.h>
20 
21 #define PTF_HORIZONTAL	(0UL)
22 #define PTF_VERTICAL	(1UL)
23 #define PTF_CHECK	(2UL)
24 
25 struct mask_info {
26 	struct mask_info *next;
27 	unsigned char id;
28 	cpumask_t mask;
29 };
30 
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 struct timer_list topology_timer;
35 static void set_topology_timer(void);
36 static DECLARE_WORK(topology_work, topology_work_fn);
37 /* topology_lock protects the core linked list */
38 static DEFINE_SPINLOCK(topology_lock);
39 
40 static struct mask_info core_info;
41 cpumask_t cpu_core_map[NR_CPUS];
42 unsigned char cpu_core_id[NR_CPUS];
43 
44 #ifdef CONFIG_SCHED_BOOK
45 static struct mask_info book_info;
46 cpumask_t cpu_book_map[NR_CPUS];
47 unsigned char cpu_book_id[NR_CPUS];
48 #endif
49 
50 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
51 {
52 	cpumask_t mask;
53 
54 	cpumask_clear(&mask);
55 	if (!topology_enabled || !MACHINE_HAS_TOPOLOGY) {
56 		cpumask_copy(&mask, cpumask_of(cpu));
57 		return mask;
58 	}
59 	while (info) {
60 		if (cpumask_test_cpu(cpu, &info->mask)) {
61 			mask = info->mask;
62 			break;
63 		}
64 		info = info->next;
65 	}
66 	if (cpumask_empty(&mask))
67 		cpumask_copy(&mask, cpumask_of(cpu));
68 	return mask;
69 }
70 
71 static struct mask_info *add_cpus_to_mask(struct topology_cpu *tl_cpu,
72 					  struct mask_info *book,
73 					  struct mask_info *core,
74 					  int z10)
75 {
76 	unsigned int cpu;
77 
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))
81 	{
82 		unsigned int rcpu, lcpu;
83 
84 		rcpu = TOPOLOGY_CPU_BITS - 1 - cpu + tl_cpu->origin;
85 		for_each_present_cpu(lcpu) {
86 			if (cpu_logical_map(lcpu) != rcpu)
87 				continue;
88 #ifdef CONFIG_SCHED_BOOK
89 			cpumask_set_cpu(lcpu, &book->mask);
90 			cpu_book_id[lcpu] = book->id;
91 #endif
92 			cpumask_set_cpu(lcpu, &core->mask);
93 			if (z10) {
94 				cpu_core_id[lcpu] = rcpu;
95 				core = core->next;
96 			} else {
97 				cpu_core_id[lcpu] = core->id;
98 			}
99 			smp_cpu_polarization[lcpu] = tl_cpu->pp;
100 		}
101 	}
102 	return core;
103 }
104 
105 static void clear_masks(void)
106 {
107 	struct mask_info *info;
108 
109 	info = &core_info;
110 	while (info) {
111 		cpumask_clear(&info->mask);
112 		info = info->next;
113 	}
114 #ifdef CONFIG_SCHED_BOOK
115 	info = &book_info;
116 	while (info) {
117 		cpumask_clear(&info->mask);
118 		info = info->next;
119 	}
120 #endif
121 }
122 
123 static union topology_entry *next_tle(union topology_entry *tle)
124 {
125 	if (!tle->nl)
126 		return (union topology_entry *)((struct topology_cpu *)tle + 1);
127 	return (union topology_entry *)((struct topology_container *)tle + 1);
128 }
129 
130 static void tl_to_cores(struct sysinfo_15_1_x *info)
131 {
132 #ifdef CONFIG_SCHED_BOOK
133 	struct mask_info *book = &book_info;
134 	struct cpuid cpu_id;
135 #else
136 	struct mask_info *book = NULL;
137 #endif
138 	struct mask_info *core = &core_info;
139 	union topology_entry *tle, *end;
140 	int z10 = 0;
141 
142 #ifdef CONFIG_SCHED_BOOK
143 	get_cpu_id(&cpu_id);
144 	z10 = cpu_id.machine == 0x2097 || cpu_id.machine == 0x2098;
145 #endif
146 	spin_lock_irq(&topology_lock);
147 	clear_masks();
148 	tle = info->tle;
149 	end = (union topology_entry *)((unsigned long)info + info->length);
150 	while (tle < end) {
151 #ifdef CONFIG_SCHED_BOOK
152 		if (z10) {
153 			switch (tle->nl) {
154 			case 1:
155 				book = book->next;
156 				book->id = tle->container.id;
157 				break;
158 			case 0:
159 				core = add_cpus_to_mask(&tle->cpu, book, core, z10);
160 				break;
161 			default:
162 				clear_masks();
163 				goto out;
164 			}
165 			tle = next_tle(tle);
166 			continue;
167 		}
168 #endif
169 		switch (tle->nl) {
170 #ifdef CONFIG_SCHED_BOOK
171 		case 2:
172 			book = book->next;
173 			book->id = tle->container.id;
174 			break;
175 #endif
176 		case 1:
177 			core = core->next;
178 			core->id = tle->container.id;
179 			break;
180 		case 0:
181 			add_cpus_to_mask(&tle->cpu, book, core, z10);
182 			break;
183 		default:
184 			clear_masks();
185 			goto out;
186 		}
187 		tle = next_tle(tle);
188 	}
189 out:
190 	spin_unlock_irq(&topology_lock);
191 }
192 
193 static void topology_update_polarization_simple(void)
194 {
195 	int cpu;
196 
197 	mutex_lock(&smp_cpu_state_mutex);
198 	for_each_possible_cpu(cpu)
199 		smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
200 	mutex_unlock(&smp_cpu_state_mutex);
201 }
202 
203 static int ptf(unsigned long fc)
204 {
205 	int rc;
206 
207 	asm volatile(
208 		"	.insn	rre,0xb9a20000,%1,%1\n"
209 		"	ipm	%0\n"
210 		"	srl	%0,28\n"
211 		: "=d" (rc)
212 		: "d" (fc)  : "cc");
213 	return rc;
214 }
215 
216 int topology_set_cpu_management(int fc)
217 {
218 	int cpu;
219 	int rc;
220 
221 	if (!MACHINE_HAS_TOPOLOGY)
222 		return -EOPNOTSUPP;
223 	if (fc)
224 		rc = ptf(PTF_VERTICAL);
225 	else
226 		rc = ptf(PTF_HORIZONTAL);
227 	if (rc)
228 		return -EBUSY;
229 	for_each_possible_cpu(cpu)
230 		smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
231 	return rc;
232 }
233 
234 static void update_cpu_core_map(void)
235 {
236 	unsigned long flags;
237 	int cpu;
238 
239 	spin_lock_irqsave(&topology_lock, flags);
240 	for_each_possible_cpu(cpu) {
241 		cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
242 #ifdef CONFIG_SCHED_BOOK
243 		cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
244 #endif
245 	}
246 	spin_unlock_irqrestore(&topology_lock, flags);
247 }
248 
249 void store_topology(struct sysinfo_15_1_x *info)
250 {
251 #ifdef CONFIG_SCHED_BOOK
252 	int rc;
253 
254 	rc = stsi(info, 15, 1, 3);
255 	if (rc != -ENOSYS)
256 		return;
257 #endif
258 	stsi(info, 15, 1, 2);
259 }
260 
261 int arch_update_cpu_topology(void)
262 {
263 	struct sysinfo_15_1_x *info = tl_info;
264 	struct sys_device *sysdev;
265 	int cpu;
266 
267 	if (!MACHINE_HAS_TOPOLOGY) {
268 		update_cpu_core_map();
269 		topology_update_polarization_simple();
270 		return 0;
271 	}
272 	store_topology(info);
273 	tl_to_cores(info);
274 	update_cpu_core_map();
275 	for_each_online_cpu(cpu) {
276 		sysdev = get_cpu_sysdev(cpu);
277 		kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
278 	}
279 	return 1;
280 }
281 
282 static void topology_work_fn(struct work_struct *work)
283 {
284 	rebuild_sched_domains();
285 }
286 
287 void topology_schedule_update(void)
288 {
289 	schedule_work(&topology_work);
290 }
291 
292 static void topology_timer_fn(unsigned long ignored)
293 {
294 	if (ptf(PTF_CHECK))
295 		topology_schedule_update();
296 	set_topology_timer();
297 }
298 
299 static void set_topology_timer(void)
300 {
301 	topology_timer.function = topology_timer_fn;
302 	topology_timer.data = 0;
303 	topology_timer.expires = jiffies + 60 * HZ;
304 	add_timer(&topology_timer);
305 }
306 
307 static int __init early_parse_topology(char *p)
308 {
309 	if (strncmp(p, "off", 3))
310 		return 0;
311 	topology_enabled = 0;
312 	return 0;
313 }
314 early_param("topology", early_parse_topology);
315 
316 static int __init init_topology_update(void)
317 {
318 	int rc;
319 
320 	rc = 0;
321 	if (!MACHINE_HAS_TOPOLOGY) {
322 		topology_update_polarization_simple();
323 		goto out;
324 	}
325 	init_timer_deferrable(&topology_timer);
326 	set_topology_timer();
327 out:
328 	update_cpu_core_map();
329 	return rc;
330 }
331 __initcall(init_topology_update);
332 
333 static void __init alloc_masks(struct sysinfo_15_1_x *info,
334 			       struct mask_info *mask, int offset)
335 {
336 	int i, nr_masks;
337 
338 	nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
339 	for (i = 0; i < info->mnest - offset; i++)
340 		nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
341 	nr_masks = max(nr_masks, 1);
342 	for (i = 0; i < nr_masks; i++) {
343 		mask->next = alloc_bootmem(sizeof(struct mask_info));
344 		mask = mask->next;
345 	}
346 }
347 
348 void __init s390_init_cpu_topology(void)
349 {
350 	struct sysinfo_15_1_x *info;
351 	int i;
352 
353 	if (!MACHINE_HAS_TOPOLOGY)
354 		return;
355 	tl_info = alloc_bootmem_pages(PAGE_SIZE);
356 	info = tl_info;
357 	store_topology(info);
358 	pr_info("The CPU configuration topology of the machine is:");
359 	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
360 		printk(" %d", info->mag[i]);
361 	printk(" / %d\n", info->mnest);
362 	alloc_masks(info, &core_info, 1);
363 #ifdef CONFIG_SCHED_BOOK
364 	alloc_masks(info, &book_info, 2);
365 #endif
366 }
367