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[S390] topology: export cpu topology via proc/sysinfo
[~shefty/rdma-dev.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
22 #define PTF_HORIZONTAL  (0UL)
23 #define PTF_VERTICAL    (1UL)
24 #define PTF_CHECK       (2UL)
25
26 struct mask_info {
27         struct mask_info *next;
28         unsigned char id;
29         cpumask_t mask;
30 };
31
32 static int topology_enabled = 1;
33 static void topology_work_fn(struct work_struct *work);
34 static struct sysinfo_15_1_x *tl_info;
35 static struct timer_list topology_timer;
36 static void set_topology_timer(void);
37 static DECLARE_WORK(topology_work, topology_work_fn);
38 /* topology_lock protects the core linked list */
39 static DEFINE_SPINLOCK(topology_lock);
40
41 static struct mask_info core_info;
42 cpumask_t cpu_core_map[NR_CPUS];
43 unsigned char cpu_core_id[NR_CPUS];
44
45 #ifdef CONFIG_SCHED_BOOK
46 static struct mask_info book_info;
47 cpumask_t cpu_book_map[NR_CPUS];
48 unsigned char cpu_book_id[NR_CPUS];
49 #endif
50
51 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
52 {
53         cpumask_t mask;
54
55         cpus_clear(mask);
56         if (!topology_enabled || !MACHINE_HAS_TOPOLOGY)
57                 return cpu_possible_map;
58         while (info) {
59                 if (cpu_isset(cpu, info->mask)) {
60                         mask = info->mask;
61                         break;
62                 }
63                 info = info->next;
64         }
65         if (cpus_empty(mask))
66                 mask = cpumask_of_cpu(cpu);
67         return mask;
68 }
69
70 static void add_cpus_to_mask(struct topology_cpu *tl_cpu,
71                              struct mask_info *book, struct mask_info *core)
72 {
73         unsigned int cpu;
74
75         for (cpu = find_first_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS);
76              cpu < TOPOLOGY_CPU_BITS;
77              cpu = find_next_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS, cpu + 1))
78         {
79                 unsigned int rcpu, lcpu;
80
81                 rcpu = TOPOLOGY_CPU_BITS - 1 - cpu + tl_cpu->origin;
82                 for_each_present_cpu(lcpu) {
83                         if (cpu_logical_map(lcpu) != rcpu)
84                                 continue;
85 #ifdef CONFIG_SCHED_BOOK
86                         cpu_set(lcpu, book->mask);
87                         cpu_book_id[lcpu] = book->id;
88 #endif
89                         cpu_set(lcpu, core->mask);
90                         cpu_core_id[lcpu] = core->id;
91                         smp_cpu_polarization[lcpu] = tl_cpu->pp;
92                 }
93         }
94 }
95
96 static void clear_masks(void)
97 {
98         struct mask_info *info;
99
100         info = &core_info;
101         while (info) {
102                 cpus_clear(info->mask);
103                 info = info->next;
104         }
105 #ifdef CONFIG_SCHED_BOOK
106         info = &book_info;
107         while (info) {
108                 cpus_clear(info->mask);
109                 info = info->next;
110         }
111 #endif
112 }
113
114 static union topology_entry *next_tle(union topology_entry *tle)
115 {
116         if (!tle->nl)
117                 return (union topology_entry *)((struct topology_cpu *)tle + 1);
118         return (union topology_entry *)((struct topology_container *)tle + 1);
119 }
120
121 static void tl_to_cores(struct sysinfo_15_1_x *info)
122 {
123 #ifdef CONFIG_SCHED_BOOK
124         struct mask_info *book = &book_info;
125 #else
126         struct mask_info *book = NULL;
127 #endif
128         struct mask_info *core = &core_info;
129         union topology_entry *tle, *end;
130
131
132         spin_lock_irq(&topology_lock);
133         clear_masks();
134         tle = info->tle;
135         end = (union topology_entry *)((unsigned long)info + info->length);
136         while (tle < end) {
137                 switch (tle->nl) {
138 #ifdef CONFIG_SCHED_BOOK
139                 case 2:
140                         book = book->next;
141                         book->id = tle->container.id;
142                         break;
143 #endif
144                 case 1:
145                         core = core->next;
146                         core->id = tle->container.id;
147                         break;
148                 case 0:
149                         add_cpus_to_mask(&tle->cpu, book, core);
150                         break;
151                 default:
152                         clear_masks();
153                         goto out;
154                 }
155                 tle = next_tle(tle);
156         }
157 out:
158         spin_unlock_irq(&topology_lock);
159 }
160
161 static void topology_update_polarization_simple(void)
162 {
163         int cpu;
164
165         mutex_lock(&smp_cpu_state_mutex);
166         for_each_possible_cpu(cpu)
167                 smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
168         mutex_unlock(&smp_cpu_state_mutex);
169 }
170
171 static int ptf(unsigned long fc)
172 {
173         int rc;
174
175         asm volatile(
176                 "       .insn   rre,0xb9a20000,%1,%1\n"
177                 "       ipm     %0\n"
178                 "       srl     %0,28\n"
179                 : "=d" (rc)
180                 : "d" (fc)  : "cc");
181         return rc;
182 }
183
184 int topology_set_cpu_management(int fc)
185 {
186         int cpu;
187         int rc;
188
189         if (!MACHINE_HAS_TOPOLOGY)
190                 return -EOPNOTSUPP;
191         if (fc)
192                 rc = ptf(PTF_VERTICAL);
193         else
194                 rc = ptf(PTF_HORIZONTAL);
195         if (rc)
196                 return -EBUSY;
197         for_each_possible_cpu(cpu)
198                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
199         return rc;
200 }
201
202 static void update_cpu_core_map(void)
203 {
204         unsigned long flags;
205         int cpu;
206
207         spin_lock_irqsave(&topology_lock, flags);
208         for_each_possible_cpu(cpu) {
209                 cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
210 #ifdef CONFIG_SCHED_BOOK
211                 cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
212 #endif
213         }
214         spin_unlock_irqrestore(&topology_lock, flags);
215 }
216
217 void store_topology(struct sysinfo_15_1_x *info)
218 {
219 #ifdef CONFIG_SCHED_BOOK
220         int rc;
221
222         rc = stsi(info, 15, 1, 3);
223         if (rc != -ENOSYS)
224                 return;
225 #endif
226         stsi(info, 15, 1, 2);
227 }
228
229 int arch_update_cpu_topology(void)
230 {
231         struct sysinfo_15_1_x *info = tl_info;
232         struct sys_device *sysdev;
233         int cpu;
234
235         if (!MACHINE_HAS_TOPOLOGY) {
236                 update_cpu_core_map();
237                 topology_update_polarization_simple();
238                 return 0;
239         }
240         store_topology(info);
241         tl_to_cores(info);
242         update_cpu_core_map();
243         for_each_online_cpu(cpu) {
244                 sysdev = get_cpu_sysdev(cpu);
245                 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
246         }
247         return 1;
248 }
249
250 static void topology_work_fn(struct work_struct *work)
251 {
252         rebuild_sched_domains();
253 }
254
255 void topology_schedule_update(void)
256 {
257         schedule_work(&topology_work);
258 }
259
260 static void topology_timer_fn(unsigned long ignored)
261 {
262         if (ptf(PTF_CHECK))
263                 topology_schedule_update();
264         set_topology_timer();
265 }
266
267 static void set_topology_timer(void)
268 {
269         topology_timer.function = topology_timer_fn;
270         topology_timer.data = 0;
271         topology_timer.expires = jiffies + 60 * HZ;
272         add_timer(&topology_timer);
273 }
274
275 static int __init early_parse_topology(char *p)
276 {
277         if (strncmp(p, "off", 3))
278                 return 0;
279         topology_enabled = 0;
280         return 0;
281 }
282 early_param("topology", early_parse_topology);
283
284 static int __init init_topology_update(void)
285 {
286         int rc;
287
288         rc = 0;
289         if (!MACHINE_HAS_TOPOLOGY) {
290                 topology_update_polarization_simple();
291                 goto out;
292         }
293         init_timer_deferrable(&topology_timer);
294         set_topology_timer();
295 out:
296         update_cpu_core_map();
297         return rc;
298 }
299 __initcall(init_topology_update);
300
301 static void alloc_masks(struct sysinfo_15_1_x *info, struct mask_info *mask,
302                         int offset)
303 {
304         int i, nr_masks;
305
306         nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
307         for (i = 0; i < info->mnest - offset; i++)
308                 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
309         nr_masks = max(nr_masks, 1);
310         for (i = 0; i < nr_masks; i++) {
311                 mask->next = alloc_bootmem(sizeof(struct mask_info));
312                 mask = mask->next;
313         }
314 }
315
316 void __init s390_init_cpu_topology(void)
317 {
318         struct sysinfo_15_1_x *info;
319         int i;
320
321         if (!MACHINE_HAS_TOPOLOGY)
322                 return;
323         tl_info = alloc_bootmem_pages(PAGE_SIZE);
324         info = tl_info;
325         store_topology(info);
326         pr_info("The CPU configuration topology of the machine is:");
327         for (i = 0; i < TOPOLOGY_NR_MAG; i++)
328                 printk(" %d", info->mag[i]);
329         printk(" / %d\n", info->mnest);
330         alloc_masks(info, &core_info, 2);
331 #ifdef CONFIG_SCHED_BOOK
332         alloc_masks(info, &book_info, 3);
333 #endif
334 }