[S390] topology: change default
[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[7];
41         unsigned char id;
42 };
43
44 union tl_entry {
45         unsigned char nl;
46         struct tl_cpu cpu;
47         struct tl_container container;
48 };
49
50 struct tl_info {
51         unsigned char reserved0[2];
52         unsigned short length;
53         unsigned char mag[NR_MAG];
54         unsigned char reserved1;
55         unsigned char mnest;
56         unsigned char reserved2[4];
57         union tl_entry tle[0];
58 };
59
60 struct mask_info {
61         struct mask_info *next;
62         unsigned char id;
63         cpumask_t mask;
64 };
65
66 static int topology_enabled = 1;
67 static void topology_work_fn(struct work_struct *work);
68 static struct tl_info *tl_info;
69 static int machine_has_topology;
70 static struct timer_list topology_timer;
71 static void set_topology_timer(void);
72 static DECLARE_WORK(topology_work, topology_work_fn);
73 /* topology_lock protects the core linked list */
74 static DEFINE_SPINLOCK(topology_lock);
75
76 static struct mask_info core_info;
77 cpumask_t cpu_core_map[NR_CPUS];
78 unsigned char cpu_core_id[NR_CPUS];
79
80 #ifdef CONFIG_SCHED_BOOK
81 static struct mask_info book_info;
82 cpumask_t cpu_book_map[NR_CPUS];
83 unsigned char cpu_book_id[NR_CPUS];
84 #endif
85
86 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
87 {
88         cpumask_t mask;
89
90         cpus_clear(mask);
91         if (!topology_enabled || !machine_has_topology)
92                 return cpu_possible_map;
93         while (info) {
94                 if (cpu_isset(cpu, info->mask)) {
95                         mask = info->mask;
96                         break;
97                 }
98                 info = info->next;
99         }
100         if (cpus_empty(mask))
101                 mask = cpumask_of_cpu(cpu);
102         return mask;
103 }
104
105 static void add_cpus_to_mask(struct tl_cpu *tl_cpu, struct mask_info *book,
106                              struct mask_info *core)
107 {
108         unsigned int cpu;
109
110         for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
111              cpu < CPU_BITS;
112              cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
113         {
114                 unsigned int rcpu, lcpu;
115
116                 rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
117                 for_each_present_cpu(lcpu) {
118                         if (cpu_logical_map(lcpu) != rcpu)
119                                 continue;
120 #ifdef CONFIG_SCHED_BOOK
121                         cpu_set(lcpu, book->mask);
122                         cpu_book_id[lcpu] = book->id;
123 #endif
124                         cpu_set(lcpu, core->mask);
125                         cpu_core_id[lcpu] = core->id;
126                         smp_cpu_polarization[lcpu] = tl_cpu->pp;
127                 }
128         }
129 }
130
131 static void clear_masks(void)
132 {
133         struct mask_info *info;
134
135         info = &core_info;
136         while (info) {
137                 cpus_clear(info->mask);
138                 info = info->next;
139         }
140 #ifdef CONFIG_SCHED_BOOK
141         info = &book_info;
142         while (info) {
143                 cpus_clear(info->mask);
144                 info = info->next;
145         }
146 #endif
147 }
148
149 static union tl_entry *next_tle(union tl_entry *tle)
150 {
151         if (tle->nl)
152                 return (union tl_entry *)((struct tl_container *)tle + 1);
153         else
154                 return (union tl_entry *)((struct tl_cpu *)tle + 1);
155 }
156
157 static void tl_to_cores(struct tl_info *info)
158 {
159 #ifdef CONFIG_SCHED_BOOK
160         struct mask_info *book = &book_info;
161 #else
162         struct mask_info *book = NULL;
163 #endif
164         struct mask_info *core = &core_info;
165         union tl_entry *tle, *end;
166
167
168         spin_lock_irq(&topology_lock);
169         clear_masks();
170         tle = info->tle;
171         end = (union tl_entry *)((unsigned long)info + info->length);
172         while (tle < end) {
173                 switch (tle->nl) {
174 #ifdef CONFIG_SCHED_BOOK
175                 case 2:
176                         book = book->next;
177                         book->id = tle->container.id;
178                         break;
179 #endif
180                 case 1:
181                         core = core->next;
182                         core->id = tle->container.id;
183                         break;
184                 case 0:
185                         add_cpus_to_mask(&tle->cpu, book, core);
186                         break;
187                 default:
188                         clear_masks();
189                         machine_has_topology = 0;
190                         goto out;
191                 }
192                 tle = next_tle(tle);
193         }
194 out:
195         spin_unlock_irq(&topology_lock);
196 }
197
198 static void topology_update_polarization_simple(void)
199 {
200         int cpu;
201
202         mutex_lock(&smp_cpu_state_mutex);
203         for_each_possible_cpu(cpu)
204                 smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
205         mutex_unlock(&smp_cpu_state_mutex);
206 }
207
208 static int ptf(unsigned long fc)
209 {
210         int rc;
211
212         asm volatile(
213                 "       .insn   rre,0xb9a20000,%1,%1\n"
214                 "       ipm     %0\n"
215                 "       srl     %0,28\n"
216                 : "=d" (rc)
217                 : "d" (fc)  : "cc");
218         return rc;
219 }
220
221 int topology_set_cpu_management(int fc)
222 {
223         int cpu;
224         int rc;
225
226         if (!machine_has_topology)
227                 return -EOPNOTSUPP;
228         if (fc)
229                 rc = ptf(PTF_VERTICAL);
230         else
231                 rc = ptf(PTF_HORIZONTAL);
232         if (rc)
233                 return -EBUSY;
234         for_each_possible_cpu(cpu)
235                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
236         return rc;
237 }
238
239 static void update_cpu_core_map(void)
240 {
241         unsigned long flags;
242         int cpu;
243
244         spin_lock_irqsave(&topology_lock, flags);
245         for_each_possible_cpu(cpu) {
246                 cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
247 #ifdef CONFIG_SCHED_BOOK
248                 cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
249 #endif
250         }
251         spin_unlock_irqrestore(&topology_lock, flags);
252 }
253
254 static void store_topology(struct tl_info *info)
255 {
256 #ifdef CONFIG_SCHED_BOOK
257         int rc;
258
259         rc = stsi(info, 15, 1, 3);
260         if (rc != -ENOSYS)
261                 return;
262 #endif
263         stsi(info, 15, 1, 2);
264 }
265
266 int arch_update_cpu_topology(void)
267 {
268         struct tl_info *info = tl_info;
269         struct sys_device *sysdev;
270         int cpu;
271
272         if (!machine_has_topology) {
273                 update_cpu_core_map();
274                 topology_update_polarization_simple();
275                 return 0;
276         }
277         store_topology(info);
278         tl_to_cores(info);
279         update_cpu_core_map();
280         for_each_online_cpu(cpu) {
281                 sysdev = get_cpu_sysdev(cpu);
282                 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
283         }
284         return 1;
285 }
286
287 static void topology_work_fn(struct work_struct *work)
288 {
289         rebuild_sched_domains();
290 }
291
292 void topology_schedule_update(void)
293 {
294         schedule_work(&topology_work);
295 }
296
297 static void topology_timer_fn(unsigned long ignored)
298 {
299         if (ptf(PTF_CHECK))
300                 topology_schedule_update();
301         set_topology_timer();
302 }
303
304 static void set_topology_timer(void)
305 {
306         topology_timer.function = topology_timer_fn;
307         topology_timer.data = 0;
308         topology_timer.expires = jiffies + 60 * HZ;
309         add_timer(&topology_timer);
310 }
311
312 static int __init early_parse_topology(char *p)
313 {
314         if (strncmp(p, "off", 3))
315                 return 0;
316         topology_enabled = 0;
317         return 0;
318 }
319 early_param("topology", early_parse_topology);
320
321 static int __init init_topology_update(void)
322 {
323         int rc;
324
325         rc = 0;
326         if (!machine_has_topology) {
327                 topology_update_polarization_simple();
328                 goto out;
329         }
330         init_timer_deferrable(&topology_timer);
331         set_topology_timer();
332 out:
333         update_cpu_core_map();
334         return rc;
335 }
336 __initcall(init_topology_update);
337
338 static void alloc_masks(struct tl_info *info, struct mask_info *mask, int offset)
339 {
340         int i, nr_masks;
341
342         nr_masks = info->mag[NR_MAG - offset];
343         for (i = 0; i < info->mnest - offset; i++)
344                 nr_masks *= info->mag[NR_MAG - offset - 1 - i];
345         nr_masks = max(nr_masks, 1);
346         for (i = 0; i < nr_masks; i++) {
347                 mask->next = alloc_bootmem(sizeof(struct mask_info));
348                 mask = mask->next;
349         }
350 }
351
352 void __init s390_init_cpu_topology(void)
353 {
354         unsigned long long facility_bits;
355         struct tl_info *info;
356         int i;
357
358         if (stfle(&facility_bits, 1) <= 0)
359                 return;
360         if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
361                 return;
362         machine_has_topology = 1;
363
364         tl_info = alloc_bootmem_pages(PAGE_SIZE);
365         info = tl_info;
366         store_topology(info);
367         pr_info("The CPU configuration topology of the machine is:");
368         for (i = 0; i < NR_MAG; i++)
369                 printk(" %d", info->mag[i]);
370         printk(" / %d\n", info->mnest);
371         alloc_masks(info, &core_info, 2);
372 #ifdef CONFIG_SCHED_BOOK
373         alloc_masks(info, &book_info, 3);
374 #endif
375 }