xref: /openbmc/linux/arch/s390/kernel/topology.c (revision 9ac8d3fb)
1 /*
2  *    Copyright IBM Corp. 2007
3  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
4  */
5 
6 #include <linux/kernel.h>
7 #include <linux/mm.h>
8 #include <linux/init.h>
9 #include <linux/device.h>
10 #include <linux/bootmem.h>
11 #include <linux/sched.h>
12 #include <linux/workqueue.h>
13 #include <linux/cpu.h>
14 #include <linux/smp.h>
15 #include <asm/delay.h>
16 #include <asm/s390_ext.h>
17 #include <asm/sysinfo.h>
18 
19 #define CPU_BITS 64
20 #define NR_MAG 6
21 
22 #define PTF_HORIZONTAL	(0UL)
23 #define PTF_VERTICAL	(1UL)
24 #define PTF_CHECK	(2UL)
25 
26 struct tl_cpu {
27 	unsigned char reserved0[4];
28 	unsigned char :6;
29 	unsigned char pp:2;
30 	unsigned char reserved1;
31 	unsigned short origin;
32 	unsigned long mask[CPU_BITS / BITS_PER_LONG];
33 };
34 
35 struct tl_container {
36 	unsigned char reserved[8];
37 };
38 
39 union tl_entry {
40 	unsigned char nl;
41 	struct tl_cpu cpu;
42 	struct tl_container container;
43 };
44 
45 struct tl_info {
46 	unsigned char reserved0[2];
47 	unsigned short length;
48 	unsigned char mag[NR_MAG];
49 	unsigned char reserved1;
50 	unsigned char mnest;
51 	unsigned char reserved2[4];
52 	union tl_entry tle[0];
53 };
54 
55 struct core_info {
56 	struct core_info *next;
57 	cpumask_t mask;
58 };
59 
60 static void topology_work_fn(struct work_struct *work);
61 static struct tl_info *tl_info;
62 static struct core_info core_info;
63 static int machine_has_topology;
64 static int machine_has_topology_irq;
65 static struct timer_list topology_timer;
66 static void set_topology_timer(void);
67 static DECLARE_WORK(topology_work, topology_work_fn);
68 
69 cpumask_t cpu_core_map[NR_CPUS];
70 
71 cpumask_t cpu_coregroup_map(unsigned int cpu)
72 {
73 	struct core_info *core = &core_info;
74 	cpumask_t mask;
75 
76 	cpus_clear(mask);
77 	if (!machine_has_topology)
78 		return cpu_present_map;
79 	mutex_lock(&smp_cpu_state_mutex);
80 	while (core) {
81 		if (cpu_isset(cpu, core->mask)) {
82 			mask = core->mask;
83 			break;
84 		}
85 		core = core->next;
86 	}
87 	mutex_unlock(&smp_cpu_state_mutex);
88 	if (cpus_empty(mask))
89 		mask = cpumask_of_cpu(cpu);
90 	return mask;
91 }
92 
93 static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
94 {
95 	unsigned int cpu;
96 
97 	for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
98 	     cpu < CPU_BITS;
99 	     cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
100 	{
101 		unsigned int rcpu, lcpu;
102 
103 		rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
104 		for_each_present_cpu(lcpu) {
105 			if (__cpu_logical_map[lcpu] == rcpu) {
106 				cpu_set(lcpu, core->mask);
107 				smp_cpu_polarization[lcpu] = tl_cpu->pp;
108 			}
109 		}
110 	}
111 }
112 
113 static void clear_cores(void)
114 {
115 	struct core_info *core = &core_info;
116 
117 	while (core) {
118 		cpus_clear(core->mask);
119 		core = core->next;
120 	}
121 }
122 
123 static union tl_entry *next_tle(union tl_entry *tle)
124 {
125 	if (tle->nl)
126 		return (union tl_entry *)((struct tl_container *)tle + 1);
127 	else
128 		return (union tl_entry *)((struct tl_cpu *)tle + 1);
129 }
130 
131 static void tl_to_cores(struct tl_info *info)
132 {
133 	union tl_entry *tle, *end;
134 	struct core_info *core = &core_info;
135 
136 	mutex_lock(&smp_cpu_state_mutex);
137 	clear_cores();
138 	tle = info->tle;
139 	end = (union tl_entry *)((unsigned long)info + info->length);
140 	while (tle < end) {
141 		switch (tle->nl) {
142 		case 5:
143 		case 4:
144 		case 3:
145 		case 2:
146 			break;
147 		case 1:
148 			core = core->next;
149 			break;
150 		case 0:
151 			add_cpus_to_core(&tle->cpu, core);
152 			break;
153 		default:
154 			clear_cores();
155 			machine_has_topology = 0;
156 			return;
157 		}
158 		tle = next_tle(tle);
159 	}
160 	mutex_unlock(&smp_cpu_state_mutex);
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_present_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_present_cpu(cpu)
200 		smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
201 	return rc;
202 }
203 
204 static void update_cpu_core_map(void)
205 {
206 	int cpu;
207 
208 	for_each_present_cpu(cpu)
209 		cpu_core_map[cpu] = cpu_coregroup_map(cpu);
210 }
211 
212 void arch_update_cpu_topology(void)
213 {
214 	struct tl_info *info = tl_info;
215 	struct sys_device *sysdev;
216 	int cpu;
217 
218 	if (!machine_has_topology) {
219 		update_cpu_core_map();
220 		topology_update_polarization_simple();
221 		return;
222 	}
223 	stsi(info, 15, 1, 2);
224 	tl_to_cores(info);
225 	update_cpu_core_map();
226 	for_each_online_cpu(cpu) {
227 		sysdev = get_cpu_sysdev(cpu);
228 		kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
229 	}
230 }
231 
232 static void topology_work_fn(struct work_struct *work)
233 {
234 	arch_reinit_sched_domains();
235 }
236 
237 void topology_schedule_update(void)
238 {
239 	schedule_work(&topology_work);
240 }
241 
242 static void topology_timer_fn(unsigned long ignored)
243 {
244 	if (ptf(PTF_CHECK))
245 		topology_schedule_update();
246 	set_topology_timer();
247 }
248 
249 static void set_topology_timer(void)
250 {
251 	topology_timer.function = topology_timer_fn;
252 	topology_timer.data = 0;
253 	topology_timer.expires = jiffies + 60 * HZ;
254 	add_timer(&topology_timer);
255 }
256 
257 static void topology_interrupt(__u16 code)
258 {
259 	schedule_work(&topology_work);
260 }
261 
262 static int __init init_topology_update(void)
263 {
264 	int rc;
265 
266 	rc = 0;
267 	if (!machine_has_topology) {
268 		topology_update_polarization_simple();
269 		goto out;
270 	}
271 	init_timer_deferrable(&topology_timer);
272 	if (machine_has_topology_irq) {
273 		rc = register_external_interrupt(0x2005, topology_interrupt);
274 		if (rc)
275 			goto out;
276 		ctl_set_bit(0, 8);
277 	}
278 	else
279 		set_topology_timer();
280 out:
281 	update_cpu_core_map();
282 	return rc;
283 }
284 __initcall(init_topology_update);
285 
286 void __init s390_init_cpu_topology(void)
287 {
288 	unsigned long long facility_bits;
289 	struct tl_info *info;
290 	struct core_info *core;
291 	int nr_cores;
292 	int i;
293 
294 	if (stfle(&facility_bits, 1) <= 0)
295 		return;
296 	if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
297 		return;
298 	machine_has_topology = 1;
299 
300 	if (facility_bits & (1ULL << 51))
301 		machine_has_topology_irq = 1;
302 
303 	tl_info = alloc_bootmem_pages(PAGE_SIZE);
304 	info = tl_info;
305 	stsi(info, 15, 1, 2);
306 
307 	nr_cores = info->mag[NR_MAG - 2];
308 	for (i = 0; i < info->mnest - 2; i++)
309 		nr_cores *= info->mag[NR_MAG - 3 - i];
310 
311 	printk(KERN_INFO "CPU topology:");
312 	for (i = 0; i < NR_MAG; i++)
313 		printk(" %d", info->mag[i]);
314 	printk(" / %d\n", info->mnest);
315 
316 	core = &core_info;
317 	for (i = 0; i < nr_cores; i++) {
318 		core->next = alloc_bootmem(sizeof(struct core_info));
319 		core = core->next;
320 		if (!core)
321 			goto error;
322 	}
323 	return;
324 error:
325 	machine_has_topology = 0;
326 	machine_has_topology_irq = 0;
327 }
328