xref: /linux/arch/s390/kernel/topology.c (revision 765532c8aaac624b5f8687af6d319c6a1138a257)
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 #include <asm/s390_ext.h>
21 
22 #define PTF_HORIZONTAL	(0UL)
23 #define PTF_VERTICAL	(1UL)
24 #define PTF_CHECK	(2UL)
25 
26 struct mask_info {
27 	struct mask_info *next;
28 	unsigned char id;
29 	cpumask_t mask;
30 };
31 
32 static int topology_enabled = 1;
33 static void topology_work_fn(struct work_struct *work);
34 static struct sysinfo_15_1_x *tl_info;
35 static struct timer_list topology_timer;
36 static void set_topology_timer(void);
37 static DECLARE_WORK(topology_work, topology_work_fn);
38 /* topology_lock protects the core linked list */
39 static DEFINE_SPINLOCK(topology_lock);
40 
41 static struct mask_info core_info;
42 cpumask_t cpu_core_map[NR_CPUS];
43 unsigned char cpu_core_id[NR_CPUS];
44 
45 #ifdef CONFIG_SCHED_BOOK
46 static struct mask_info book_info;
47 cpumask_t cpu_book_map[NR_CPUS];
48 unsigned char cpu_book_id[NR_CPUS];
49 #endif
50 
51 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
52 {
53 	cpumask_t mask;
54 
55 	cpus_clear(mask);
56 	if (!topology_enabled || !MACHINE_HAS_TOPOLOGY) {
57 		cpumask_copy(&mask, cpumask_of(cpu));
58 		return mask;
59 	}
60 	while (info) {
61 		if (cpu_isset(cpu, info->mask)) {
62 			mask = info->mask;
63 			break;
64 		}
65 		info = info->next;
66 	}
67 	if (cpus_empty(mask))
68 		mask = cpumask_of_cpu(cpu);
69 	return mask;
70 }
71 
72 static void add_cpus_to_mask(struct topology_cpu *tl_cpu,
73 			     struct mask_info *book, struct mask_info *core)
74 {
75 	unsigned int cpu;
76 
77 	for (cpu = find_first_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS);
78 	     cpu < TOPOLOGY_CPU_BITS;
79 	     cpu = find_next_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS, cpu + 1))
80 	{
81 		unsigned int rcpu, lcpu;
82 
83 		rcpu = TOPOLOGY_CPU_BITS - 1 - cpu + tl_cpu->origin;
84 		for_each_present_cpu(lcpu) {
85 			if (cpu_logical_map(lcpu) != rcpu)
86 				continue;
87 #ifdef CONFIG_SCHED_BOOK
88 			cpu_set(lcpu, book->mask);
89 			cpu_book_id[lcpu] = book->id;
90 #endif
91 			cpu_set(lcpu, core->mask);
92 			cpu_core_id[lcpu] = core->id;
93 			smp_cpu_polarization[lcpu] = tl_cpu->pp;
94 		}
95 	}
96 }
97 
98 static void clear_masks(void)
99 {
100 	struct mask_info *info;
101 
102 	info = &core_info;
103 	while (info) {
104 		cpus_clear(info->mask);
105 		info = info->next;
106 	}
107 #ifdef CONFIG_SCHED_BOOK
108 	info = &book_info;
109 	while (info) {
110 		cpus_clear(info->mask);
111 		info = info->next;
112 	}
113 #endif
114 }
115 
116 static union topology_entry *next_tle(union topology_entry *tle)
117 {
118 	if (!tle->nl)
119 		return (union topology_entry *)((struct topology_cpu *)tle + 1);
120 	return (union topology_entry *)((struct topology_container *)tle + 1);
121 }
122 
123 static void tl_to_cores(struct sysinfo_15_1_x *info)
124 {
125 #ifdef CONFIG_SCHED_BOOK
126 	struct mask_info *book = &book_info;
127 #else
128 	struct mask_info *book = NULL;
129 #endif
130 	struct mask_info *core = &core_info;
131 	union topology_entry *tle, *end;
132 
133 
134 	spin_lock_irq(&topology_lock);
135 	clear_masks();
136 	tle = info->tle;
137 	end = (union topology_entry *)((unsigned long)info + info->length);
138 	while (tle < end) {
139 		switch (tle->nl) {
140 #ifdef CONFIG_SCHED_BOOK
141 		case 2:
142 			book = book->next;
143 			book->id = tle->container.id;
144 			break;
145 #endif
146 		case 1:
147 			core = core->next;
148 			core->id = tle->container.id;
149 			break;
150 		case 0:
151 			add_cpus_to_mask(&tle->cpu, book, core);
152 			break;
153 		default:
154 			clear_masks();
155 			goto out;
156 		}
157 		tle = next_tle(tle);
158 	}
159 out:
160 	spin_unlock_irq(&topology_lock);
161 }
162 
163 static void topology_update_polarization_simple(void)
164 {
165 	int cpu;
166 
167 	mutex_lock(&smp_cpu_state_mutex);
168 	for_each_possible_cpu(cpu)
169 		smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
170 	mutex_unlock(&smp_cpu_state_mutex);
171 }
172 
173 static int ptf(unsigned long fc)
174 {
175 	int rc;
176 
177 	asm volatile(
178 		"	.insn	rre,0xb9a20000,%1,%1\n"
179 		"	ipm	%0\n"
180 		"	srl	%0,28\n"
181 		: "=d" (rc)
182 		: "d" (fc)  : "cc");
183 	return rc;
184 }
185 
186 int topology_set_cpu_management(int fc)
187 {
188 	int cpu;
189 	int rc;
190 
191 	if (!MACHINE_HAS_TOPOLOGY)
192 		return -EOPNOTSUPP;
193 	if (fc)
194 		rc = ptf(PTF_VERTICAL);
195 	else
196 		rc = ptf(PTF_HORIZONTAL);
197 	if (rc)
198 		return -EBUSY;
199 	for_each_possible_cpu(cpu)
200 		smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
201 	return rc;
202 }
203 
204 static void update_cpu_core_map(void)
205 {
206 	unsigned long flags;
207 	int cpu;
208 
209 	spin_lock_irqsave(&topology_lock, flags);
210 	for_each_possible_cpu(cpu) {
211 		cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
212 #ifdef CONFIG_SCHED_BOOK
213 		cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
214 #endif
215 	}
216 	spin_unlock_irqrestore(&topology_lock, flags);
217 }
218 
219 void store_topology(struct sysinfo_15_1_x *info)
220 {
221 #ifdef CONFIG_SCHED_BOOK
222 	int rc;
223 
224 	rc = stsi(info, 15, 1, 3);
225 	if (rc != -ENOSYS)
226 		return;
227 #endif
228 	stsi(info, 15, 1, 2);
229 }
230 
231 int arch_update_cpu_topology(void)
232 {
233 	struct sysinfo_15_1_x *info = tl_info;
234 	struct sys_device *sysdev;
235 	int cpu;
236 
237 	if (!MACHINE_HAS_TOPOLOGY) {
238 		update_cpu_core_map();
239 		topology_update_polarization_simple();
240 		return 0;
241 	}
242 	store_topology(info);
243 	tl_to_cores(info);
244 	update_cpu_core_map();
245 	for_each_online_cpu(cpu) {
246 		sysdev = get_cpu_sysdev(cpu);
247 		kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
248 	}
249 	return 1;
250 }
251 
252 static void topology_work_fn(struct work_struct *work)
253 {
254 	rebuild_sched_domains();
255 }
256 
257 void topology_schedule_update(void)
258 {
259 	schedule_work(&topology_work);
260 }
261 
262 static void topology_timer_fn(unsigned long ignored)
263 {
264 	if (ptf(PTF_CHECK))
265 		topology_schedule_update();
266 	set_topology_timer();
267 }
268 
269 static void set_topology_timer(void)
270 {
271 	topology_timer.function = topology_timer_fn;
272 	topology_timer.data = 0;
273 	topology_timer.expires = jiffies + 60 * HZ;
274 	add_timer(&topology_timer);
275 }
276 
277 static int __init early_parse_topology(char *p)
278 {
279 	if (strncmp(p, "off", 3))
280 		return 0;
281 	topology_enabled = 0;
282 	return 0;
283 }
284 early_param("topology", early_parse_topology);
285 
286 static int __init init_topology_update(void)
287 {
288 	int rc;
289 
290 	rc = 0;
291 	if (!MACHINE_HAS_TOPOLOGY) {
292 		topology_update_polarization_simple();
293 		goto out;
294 	}
295 	init_timer_deferrable(&topology_timer);
296 	set_topology_timer();
297 out:
298 	update_cpu_core_map();
299 	return rc;
300 }
301 __initcall(init_topology_update);
302 
303 static void alloc_masks(struct sysinfo_15_1_x *info, struct mask_info *mask,
304 			int offset)
305 {
306 	int i, nr_masks;
307 
308 	nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
309 	for (i = 0; i < info->mnest - offset; i++)
310 		nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
311 	nr_masks = max(nr_masks, 1);
312 	for (i = 0; i < nr_masks; i++) {
313 		mask->next = alloc_bootmem(sizeof(struct mask_info));
314 		mask = mask->next;
315 	}
316 }
317 
318 void __init s390_init_cpu_topology(void)
319 {
320 	struct sysinfo_15_1_x *info;
321 	int i;
322 
323 	if (!MACHINE_HAS_TOPOLOGY)
324 		return;
325 	tl_info = alloc_bootmem_pages(PAGE_SIZE);
326 	info = tl_info;
327 	store_topology(info);
328 	pr_info("The CPU configuration topology of the machine is:");
329 	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
330 		printk(" %d", info->mag[i]);
331 	printk(" / %d\n", info->mnest);
332 	alloc_masks(info, &core_info, 2);
333 #ifdef CONFIG_SCHED_BOOK
334 	alloc_masks(info, &book_info, 3);
335 #endif
336 }
337