xref: /linux/arch/s390/kernel/topology.c (revision 068df0f34e81bc06c5eb5012ec2eda25624e87aa)
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 void add_cpus_to_mask(struct topology_cpu *tl_cpu,
72 			     struct mask_info *book, struct mask_info *core)
73 {
74 	unsigned int cpu;
75 
76 	for (cpu = find_first_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS);
77 	     cpu < TOPOLOGY_CPU_BITS;
78 	     cpu = find_next_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS, cpu + 1))
79 	{
80 		unsigned int rcpu, lcpu;
81 
82 		rcpu = TOPOLOGY_CPU_BITS - 1 - cpu + tl_cpu->origin;
83 		for_each_present_cpu(lcpu) {
84 			if (cpu_logical_map(lcpu) != rcpu)
85 				continue;
86 #ifdef CONFIG_SCHED_BOOK
87 			cpumask_set_cpu(lcpu, &book->mask);
88 			cpu_book_id[lcpu] = book->id;
89 #endif
90 			cpumask_set_cpu(lcpu, &core->mask);
91 			cpu_core_id[lcpu] = core->id;
92 			smp_cpu_polarization[lcpu] = tl_cpu->pp;
93 		}
94 	}
95 }
96 
97 static void clear_masks(void)
98 {
99 	struct mask_info *info;
100 
101 	info = &core_info;
102 	while (info) {
103 		cpumask_clear(&info->mask);
104 		info = info->next;
105 	}
106 #ifdef CONFIG_SCHED_BOOK
107 	info = &book_info;
108 	while (info) {
109 		cpumask_clear(&info->mask);
110 		info = info->next;
111 	}
112 #endif
113 }
114 
115 static union topology_entry *next_tle(union topology_entry *tle)
116 {
117 	if (!tle->nl)
118 		return (union topology_entry *)((struct topology_cpu *)tle + 1);
119 	return (union topology_entry *)((struct topology_container *)tle + 1);
120 }
121 
122 static void tl_to_cores(struct sysinfo_15_1_x *info)
123 {
124 #ifdef CONFIG_SCHED_BOOK
125 	struct mask_info *book = &book_info;
126 #else
127 	struct mask_info *book = NULL;
128 #endif
129 	struct mask_info *core = &core_info;
130 	union topology_entry *tle, *end;
131 
132 
133 	spin_lock_irq(&topology_lock);
134 	clear_masks();
135 	tle = info->tle;
136 	end = (union topology_entry *)((unsigned long)info + info->length);
137 	while (tle < end) {
138 		switch (tle->nl) {
139 #ifdef CONFIG_SCHED_BOOK
140 		case 2:
141 			book = book->next;
142 			book->id = tle->container.id;
143 			break;
144 #endif
145 		case 1:
146 			core = core->next;
147 			core->id = tle->container.id;
148 			break;
149 		case 0:
150 			add_cpus_to_mask(&tle->cpu, book, core);
151 			break;
152 		default:
153 			clear_masks();
154 			goto out;
155 		}
156 		tle = next_tle(tle);
157 	}
158 out:
159 	spin_unlock_irq(&topology_lock);
160 }
161 
162 static void topology_update_polarization_simple(void)
163 {
164 	int cpu;
165 
166 	mutex_lock(&smp_cpu_state_mutex);
167 	for_each_possible_cpu(cpu)
168 		smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
169 	mutex_unlock(&smp_cpu_state_mutex);
170 }
171 
172 static int ptf(unsigned long fc)
173 {
174 	int rc;
175 
176 	asm volatile(
177 		"	.insn	rre,0xb9a20000,%1,%1\n"
178 		"	ipm	%0\n"
179 		"	srl	%0,28\n"
180 		: "=d" (rc)
181 		: "d" (fc)  : "cc");
182 	return rc;
183 }
184 
185 int topology_set_cpu_management(int fc)
186 {
187 	int cpu;
188 	int rc;
189 
190 	if (!MACHINE_HAS_TOPOLOGY)
191 		return -EOPNOTSUPP;
192 	if (fc)
193 		rc = ptf(PTF_VERTICAL);
194 	else
195 		rc = ptf(PTF_HORIZONTAL);
196 	if (rc)
197 		return -EBUSY;
198 	for_each_possible_cpu(cpu)
199 		smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
200 	return rc;
201 }
202 
203 static void update_cpu_core_map(void)
204 {
205 	unsigned long flags;
206 	int cpu;
207 
208 	spin_lock_irqsave(&topology_lock, flags);
209 	for_each_possible_cpu(cpu) {
210 		cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
211 #ifdef CONFIG_SCHED_BOOK
212 		cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
213 #endif
214 	}
215 	spin_unlock_irqrestore(&topology_lock, flags);
216 }
217 
218 void store_topology(struct sysinfo_15_1_x *info)
219 {
220 #ifdef CONFIG_SCHED_BOOK
221 	int rc;
222 
223 	rc = stsi(info, 15, 1, 3);
224 	if (rc != -ENOSYS)
225 		return;
226 #endif
227 	stsi(info, 15, 1, 2);
228 }
229 
230 int arch_update_cpu_topology(void)
231 {
232 	struct sysinfo_15_1_x *info = tl_info;
233 	struct sys_device *sysdev;
234 	int cpu;
235 
236 	if (!MACHINE_HAS_TOPOLOGY) {
237 		update_cpu_core_map();
238 		topology_update_polarization_simple();
239 		return 0;
240 	}
241 	store_topology(info);
242 	tl_to_cores(info);
243 	update_cpu_core_map();
244 	for_each_online_cpu(cpu) {
245 		sysdev = get_cpu_sysdev(cpu);
246 		kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
247 	}
248 	return 1;
249 }
250 
251 static void topology_work_fn(struct work_struct *work)
252 {
253 	rebuild_sched_domains();
254 }
255 
256 void topology_schedule_update(void)
257 {
258 	schedule_work(&topology_work);
259 }
260 
261 static void topology_timer_fn(unsigned long ignored)
262 {
263 	if (ptf(PTF_CHECK))
264 		topology_schedule_update();
265 	set_topology_timer();
266 }
267 
268 static void set_topology_timer(void)
269 {
270 	topology_timer.function = topology_timer_fn;
271 	topology_timer.data = 0;
272 	topology_timer.expires = jiffies + 60 * HZ;
273 	add_timer(&topology_timer);
274 }
275 
276 static int __init early_parse_topology(char *p)
277 {
278 	if (strncmp(p, "off", 3))
279 		return 0;
280 	topology_enabled = 0;
281 	return 0;
282 }
283 early_param("topology", early_parse_topology);
284 
285 static int __init init_topology_update(void)
286 {
287 	int rc;
288 
289 	rc = 0;
290 	if (!MACHINE_HAS_TOPOLOGY) {
291 		topology_update_polarization_simple();
292 		goto out;
293 	}
294 	init_timer_deferrable(&topology_timer);
295 	set_topology_timer();
296 out:
297 	update_cpu_core_map();
298 	return rc;
299 }
300 __initcall(init_topology_update);
301 
302 static void __init alloc_masks(struct sysinfo_15_1_x *info,
303 			       struct mask_info *mask, int offset)
304 {
305 	int i, nr_masks;
306 
307 	nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
308 	for (i = 0; i < info->mnest - offset; i++)
309 		nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
310 	nr_masks = max(nr_masks, 1);
311 	for (i = 0; i < nr_masks; i++) {
312 		mask->next = alloc_bootmem(sizeof(struct mask_info));
313 		mask = mask->next;
314 	}
315 }
316 
317 void __init s390_init_cpu_topology(void)
318 {
319 	struct sysinfo_15_1_x *info;
320 	int i;
321 
322 	if (!MACHINE_HAS_TOPOLOGY)
323 		return;
324 	tl_info = alloc_bootmem_pages(PAGE_SIZE);
325 	info = tl_info;
326 	store_topology(info);
327 	pr_info("The CPU configuration topology of the machine is:");
328 	for (i = 0; i < TOPOLOGY_NR_MAG; i++)
329 		printk(" %d", info->mag[i]);
330 	printk(" / %d\n", info->mnest);
331 	alloc_masks(info, &core_info, 2);
332 #ifdef CONFIG_SCHED_BOOK
333 	alloc_masks(info, &book_info, 3);
334 #endif
335 }
336