Merge branch 'core/stacktrace' of git://git.kernel.org/pub/scm/linux/kernel/git/tip...
[linux-2.6] / arch / s390 / kernel / topology.c
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/kthread.h>
13 #include <linux/workqueue.h>
14 #include <linux/cpu.h>
15 #include <linux/smp.h>
16 #include <asm/delay.h>
17 #include <asm/s390_ext.h>
18 #include <asm/sysinfo.h>
19
20 #define CPU_BITS 64
21 #define NR_MAG 6
22
23 #define PTF_HORIZONTAL  (0UL)
24 #define PTF_VERTICAL    (1UL)
25 #define PTF_CHECK       (2UL)
26
27 struct tl_cpu {
28         unsigned char reserved0[4];
29         unsigned char :6;
30         unsigned char pp:2;
31         unsigned char reserved1;
32         unsigned short origin;
33         unsigned long mask[CPU_BITS / BITS_PER_LONG];
34 };
35
36 struct tl_container {
37         unsigned char reserved[8];
38 };
39
40 union tl_entry {
41         unsigned char nl;
42         struct tl_cpu cpu;
43         struct tl_container container;
44 };
45
46 struct tl_info {
47         unsigned char reserved0[2];
48         unsigned short length;
49         unsigned char mag[NR_MAG];
50         unsigned char reserved1;
51         unsigned char mnest;
52         unsigned char reserved2[4];
53         union tl_entry tle[0];
54 };
55
56 struct core_info {
57         struct core_info *next;
58         cpumask_t mask;
59 };
60
61 static void topology_work_fn(struct work_struct *work);
62 static struct tl_info *tl_info;
63 static struct core_info core_info;
64 static int machine_has_topology;
65 static int machine_has_topology_irq;
66 static struct timer_list topology_timer;
67 static void set_topology_timer(void);
68 static DECLARE_WORK(topology_work, topology_work_fn);
69
70 cpumask_t cpu_core_map[NR_CPUS];
71
72 cpumask_t cpu_coregroup_map(unsigned int cpu)
73 {
74         struct core_info *core = &core_info;
75         cpumask_t mask;
76
77         cpus_clear(mask);
78         if (!machine_has_topology)
79                 return cpu_present_map;
80         mutex_lock(&smp_cpu_state_mutex);
81         while (core) {
82                 if (cpu_isset(cpu, core->mask)) {
83                         mask = core->mask;
84                         break;
85                 }
86                 core = core->next;
87         }
88         mutex_unlock(&smp_cpu_state_mutex);
89         if (cpus_empty(mask))
90                 mask = cpumask_of_cpu(cpu);
91         return mask;
92 }
93
94 static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
95 {
96         unsigned int cpu;
97
98         for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
99              cpu < CPU_BITS;
100              cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
101         {
102                 unsigned int rcpu, lcpu;
103
104                 rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
105                 for_each_present_cpu(lcpu) {
106                         if (__cpu_logical_map[lcpu] == rcpu) {
107                                 cpu_set(lcpu, core->mask);
108                                 smp_cpu_polarization[lcpu] = tl_cpu->pp;
109                         }
110                 }
111         }
112 }
113
114 static void clear_cores(void)
115 {
116         struct core_info *core = &core_info;
117
118         while (core) {
119                 cpus_clear(core->mask);
120                 core = core->next;
121         }
122 }
123
124 static union tl_entry *next_tle(union tl_entry *tle)
125 {
126         if (tle->nl)
127                 return (union tl_entry *)((struct tl_container *)tle + 1);
128         else
129                 return (union tl_entry *)((struct tl_cpu *)tle + 1);
130 }
131
132 static void tl_to_cores(struct tl_info *info)
133 {
134         union tl_entry *tle, *end;
135         struct core_info *core = &core_info;
136
137         mutex_lock(&smp_cpu_state_mutex);
138         clear_cores();
139         tle = info->tle;
140         end = (union tl_entry *)((unsigned long)info + info->length);
141         while (tle < end) {
142                 switch (tle->nl) {
143                 case 5:
144                 case 4:
145                 case 3:
146                 case 2:
147                         break;
148                 case 1:
149                         core = core->next;
150                         break;
151                 case 0:
152                         add_cpus_to_core(&tle->cpu, core);
153                         break;
154                 default:
155                         clear_cores();
156                         machine_has_topology = 0;
157                         return;
158                 }
159                 tle = next_tle(tle);
160         }
161         mutex_unlock(&smp_cpu_state_mutex);
162 }
163
164 static void topology_update_polarization_simple(void)
165 {
166         int cpu;
167
168         mutex_lock(&smp_cpu_state_mutex);
169         for_each_present_cpu(cpu)
170                 smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
171         mutex_unlock(&smp_cpu_state_mutex);
172 }
173
174 static int ptf(unsigned long fc)
175 {
176         int rc;
177
178         asm volatile(
179                 "       .insn   rre,0xb9a20000,%1,%1\n"
180                 "       ipm     %0\n"
181                 "       srl     %0,28\n"
182                 : "=d" (rc)
183                 : "d" (fc)  : "cc");
184         return rc;
185 }
186
187 int topology_set_cpu_management(int fc)
188 {
189         int cpu;
190         int rc;
191
192         if (!machine_has_topology)
193                 return -EOPNOTSUPP;
194         if (fc)
195                 rc = ptf(PTF_VERTICAL);
196         else
197                 rc = ptf(PTF_HORIZONTAL);
198         if (rc)
199                 return -EBUSY;
200         for_each_present_cpu(cpu)
201                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
202         return rc;
203 }
204
205 static void update_cpu_core_map(void)
206 {
207         int cpu;
208
209         for_each_present_cpu(cpu)
210                 cpu_core_map[cpu] = cpu_coregroup_map(cpu);
211 }
212
213 void arch_update_cpu_topology(void)
214 {
215         struct tl_info *info = tl_info;
216         struct sys_device *sysdev;
217         int cpu;
218
219         if (!machine_has_topology) {
220                 update_cpu_core_map();
221                 topology_update_polarization_simple();
222                 return;
223         }
224         stsi(info, 15, 1, 2);
225         tl_to_cores(info);
226         update_cpu_core_map();
227         for_each_online_cpu(cpu) {
228                 sysdev = get_cpu_sysdev(cpu);
229                 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
230         }
231 }
232
233 static int topology_kthread(void *data)
234 {
235         arch_reinit_sched_domains();
236         return 0;
237 }
238
239 static void topology_work_fn(struct work_struct *work)
240 {
241         /* We can't call arch_reinit_sched_domains() from a multi-threaded
242          * workqueue context since it may deadlock in case of cpu hotplug.
243          * So we have to create a kernel thread in order to call
244          * arch_reinit_sched_domains().
245          */
246         kthread_run(topology_kthread, NULL, "topology_update");
247 }
248
249 void topology_schedule_update(void)
250 {
251         schedule_work(&topology_work);
252 }
253
254 static void topology_timer_fn(unsigned long ignored)
255 {
256         if (ptf(PTF_CHECK))
257                 topology_schedule_update();
258         set_topology_timer();
259 }
260
261 static void set_topology_timer(void)
262 {
263         topology_timer.function = topology_timer_fn;
264         topology_timer.data = 0;
265         topology_timer.expires = jiffies + 60 * HZ;
266         add_timer(&topology_timer);
267 }
268
269 static void topology_interrupt(__u16 code)
270 {
271         schedule_work(&topology_work);
272 }
273
274 static int __init init_topology_update(void)
275 {
276         int rc;
277
278         rc = 0;
279         if (!machine_has_topology) {
280                 topology_update_polarization_simple();
281                 goto out;
282         }
283         init_timer_deferrable(&topology_timer);
284         if (machine_has_topology_irq) {
285                 rc = register_external_interrupt(0x2005, topology_interrupt);
286                 if (rc)
287                         goto out;
288                 ctl_set_bit(0, 8);
289         }
290         else
291                 set_topology_timer();
292 out:
293         update_cpu_core_map();
294         return rc;
295 }
296 __initcall(init_topology_update);
297
298 void __init s390_init_cpu_topology(void)
299 {
300         unsigned long long facility_bits;
301         struct tl_info *info;
302         struct core_info *core;
303         int nr_cores;
304         int i;
305
306         if (stfle(&facility_bits, 1) <= 0)
307                 return;
308         if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
309                 return;
310         machine_has_topology = 1;
311
312         if (facility_bits & (1ULL << 51))
313                 machine_has_topology_irq = 1;
314
315         tl_info = alloc_bootmem_pages(PAGE_SIZE);
316         info = tl_info;
317         stsi(info, 15, 1, 2);
318
319         nr_cores = info->mag[NR_MAG - 2];
320         for (i = 0; i < info->mnest - 2; i++)
321                 nr_cores *= info->mag[NR_MAG - 3 - i];
322
323         printk(KERN_INFO "CPU topology:");
324         for (i = 0; i < NR_MAG; i++)
325                 printk(" %d", info->mag[i]);
326         printk(" / %d\n", info->mnest);
327
328         core = &core_info;
329         for (i = 0; i < nr_cores; i++) {
330                 core->next = alloc_bootmem(sizeof(struct core_info));
331                 core = core->next;
332                 if (!core)
333                         goto error;
334         }
335         return;
336 error:
337         machine_has_topology = 0;
338         machine_has_topology_irq = 0;
339 }