Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6
[linux-2.6.git] / arch / s390 / kernel / topology.c
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 #include <asm/sysinfo.h>
22
23 #define CPU_BITS 64
24 #define NR_MAG 6
25
26 #define PTF_HORIZONTAL  (0UL)
27 #define PTF_VERTICAL    (1UL)
28 #define PTF_CHECK       (2UL)
29
30 struct tl_cpu {
31         unsigned char reserved0[4];
32         unsigned char :6;
33         unsigned char pp:2;
34         unsigned char reserved1;
35         unsigned short origin;
36         unsigned long mask[CPU_BITS / BITS_PER_LONG];
37 };
38
39 struct tl_container {
40         unsigned char reserved[8];
41 };
42
43 union tl_entry {
44         unsigned char nl;
45         struct tl_cpu cpu;
46         struct tl_container container;
47 };
48
49 struct tl_info {
50         unsigned char reserved0[2];
51         unsigned short length;
52         unsigned char mag[NR_MAG];
53         unsigned char reserved1;
54         unsigned char mnest;
55         unsigned char reserved2[4];
56         union tl_entry tle[0];
57 };
58
59 struct core_info {
60         struct core_info *next;
61         cpumask_t mask;
62 };
63
64 static int topology_enabled;
65 static void topology_work_fn(struct work_struct *work);
66 static struct tl_info *tl_info;
67 static struct core_info core_info;
68 static int machine_has_topology;
69 static struct timer_list topology_timer;
70 static void set_topology_timer(void);
71 static DECLARE_WORK(topology_work, topology_work_fn);
72 /* topology_lock protects the core linked list */
73 static DEFINE_SPINLOCK(topology_lock);
74
75 cpumask_t cpu_core_map[NR_CPUS];
76
77 cpumask_t cpu_coregroup_map(unsigned int cpu)
78 {
79         struct core_info *core = &core_info;
80         unsigned long flags;
81         cpumask_t mask;
82
83         cpus_clear(mask);
84         if (!topology_enabled || !machine_has_topology)
85                 return cpu_possible_map;
86         spin_lock_irqsave(&topology_lock, flags);
87         while (core) {
88                 if (cpu_isset(cpu, core->mask)) {
89                         mask = core->mask;
90                         break;
91                 }
92                 core = core->next;
93         }
94         spin_unlock_irqrestore(&topology_lock, flags);
95         if (cpus_empty(mask))
96                 mask = cpumask_of_cpu(cpu);
97         return mask;
98 }
99
100 const struct cpumask *cpu_coregroup_mask(unsigned int cpu)
101 {
102         return &cpu_core_map[cpu];
103 }
104
105 static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
106 {
107         unsigned int cpu;
108
109         for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
110              cpu < CPU_BITS;
111              cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
112         {
113                 unsigned int rcpu, lcpu;
114
115                 rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
116                 for_each_present_cpu(lcpu) {
117                         if (__cpu_logical_map[lcpu] == rcpu) {
118                                 cpu_set(lcpu, core->mask);
119                                 smp_cpu_polarization[lcpu] = tl_cpu->pp;
120                         }
121                 }
122         }
123 }
124
125 static void clear_cores(void)
126 {
127         struct core_info *core = &core_info;
128
129         while (core) {
130                 cpus_clear(core->mask);
131                 core = core->next;
132         }
133 }
134
135 static union tl_entry *next_tle(union tl_entry *tle)
136 {
137         if (tle->nl)
138                 return (union tl_entry *)((struct tl_container *)tle + 1);
139         else
140                 return (union tl_entry *)((struct tl_cpu *)tle + 1);
141 }
142
143 static void tl_to_cores(struct tl_info *info)
144 {
145         union tl_entry *tle, *end;
146         struct core_info *core = &core_info;
147
148         spin_lock_irq(&topology_lock);
149         clear_cores();
150         tle = info->tle;
151         end = (union tl_entry *)((unsigned long)info + info->length);
152         while (tle < end) {
153                 switch (tle->nl) {
154                 case 5:
155                 case 4:
156                 case 3:
157                 case 2:
158                         break;
159                 case 1:
160                         core = core->next;
161                         break;
162                 case 0:
163                         add_cpus_to_core(&tle->cpu, core);
164                         break;
165                 default:
166                         clear_cores();
167                         machine_has_topology = 0;
168                         return;
169                 }
170                 tle = next_tle(tle);
171         }
172         spin_unlock_irq(&topology_lock);
173 }
174
175 static void topology_update_polarization_simple(void)
176 {
177         int cpu;
178
179         mutex_lock(&smp_cpu_state_mutex);
180         for_each_possible_cpu(cpu)
181                 smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
182         mutex_unlock(&smp_cpu_state_mutex);
183 }
184
185 static int ptf(unsigned long fc)
186 {
187         int rc;
188
189         asm volatile(
190                 "       .insn   rre,0xb9a20000,%1,%1\n"
191                 "       ipm     %0\n"
192                 "       srl     %0,28\n"
193                 : "=d" (rc)
194                 : "d" (fc)  : "cc");
195         return rc;
196 }
197
198 int topology_set_cpu_management(int fc)
199 {
200         int cpu;
201         int rc;
202
203         if (!machine_has_topology)
204                 return -EOPNOTSUPP;
205         if (fc)
206                 rc = ptf(PTF_VERTICAL);
207         else
208                 rc = ptf(PTF_HORIZONTAL);
209         if (rc)
210                 return -EBUSY;
211         for_each_possible_cpu(cpu)
212                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
213         return rc;
214 }
215
216 static void update_cpu_core_map(void)
217 {
218         int cpu;
219
220         for_each_possible_cpu(cpu)
221                 cpu_core_map[cpu] = cpu_coregroup_map(cpu);
222 }
223
224 int arch_update_cpu_topology(void)
225 {
226         struct tl_info *info = tl_info;
227         struct sys_device *sysdev;
228         int cpu;
229
230         if (!machine_has_topology) {
231                 update_cpu_core_map();
232                 topology_update_polarization_simple();
233                 return 0;
234         }
235         stsi(info, 15, 1, 2);
236         tl_to_cores(info);
237         update_cpu_core_map();
238         for_each_online_cpu(cpu) {
239                 sysdev = get_cpu_sysdev(cpu);
240                 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
241         }
242         return 1;
243 }
244
245 static void topology_work_fn(struct work_struct *work)
246 {
247         rebuild_sched_domains();
248 }
249
250 void topology_schedule_update(void)
251 {
252         schedule_work(&topology_work);
253 }
254
255 static void topology_timer_fn(unsigned long ignored)
256 {
257         if (ptf(PTF_CHECK))
258                 topology_schedule_update();
259         set_topology_timer();
260 }
261
262 static void set_topology_timer(void)
263 {
264         topology_timer.function = topology_timer_fn;
265         topology_timer.data = 0;
266         topology_timer.expires = jiffies + 60 * HZ;
267         add_timer(&topology_timer);
268 }
269
270 static int __init early_parse_topology(char *p)
271 {
272         if (strncmp(p, "on", 2))
273                 return 0;
274         topology_enabled = 1;
275         return 0;
276 }
277 early_param("topology", early_parse_topology);
278
279 static int __init init_topology_update(void)
280 {
281         int rc;
282
283         rc = 0;
284         if (!machine_has_topology) {
285                 topology_update_polarization_simple();
286                 goto out;
287         }
288         init_timer_deferrable(&topology_timer);
289         set_topology_timer();
290 out:
291         update_cpu_core_map();
292         return rc;
293 }
294 __initcall(init_topology_update);
295
296 void __init s390_init_cpu_topology(void)
297 {
298         unsigned long long facility_bits;
299         struct tl_info *info;
300         struct core_info *core;
301         int nr_cores;
302         int i;
303
304         if (stfle(&facility_bits, 1) <= 0)
305                 return;
306         if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
307                 return;
308         machine_has_topology = 1;
309
310         tl_info = alloc_bootmem_pages(PAGE_SIZE);
311         info = tl_info;
312         stsi(info, 15, 1, 2);
313
314         nr_cores = info->mag[NR_MAG - 2];
315         for (i = 0; i < info->mnest - 2; i++)
316                 nr_cores *= info->mag[NR_MAG - 3 - i];
317
318         pr_info("The CPU configuration topology of the machine is:");
319         for (i = 0; i < NR_MAG; i++)
320                 printk(" %d", info->mag[i]);
321         printk(" / %d\n", info->mnest);
322
323         core = &core_info;
324         for (i = 0; i < nr_cores; i++) {
325                 core->next = alloc_bootmem(sizeof(struct core_info));
326                 core = core->next;
327                 if (!core)
328                         goto error;
329         }
330         return;
331 error:
332         machine_has_topology = 0;
333 }