]> nv-tegra.nvidia Code Review - linux-2.6.git/blob - arch/s390/kernel/topology.c
Merge branch 'for-linus' of git://git390.osdl.marist.edu/pub/scm/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 static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
101 {
102         unsigned int cpu;
103
104         for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
105              cpu < CPU_BITS;
106              cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
107         {
108                 unsigned int rcpu, lcpu;
109
110                 rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
111                 for_each_present_cpu(lcpu) {
112                         if (__cpu_logical_map[lcpu] == rcpu) {
113                                 cpu_set(lcpu, core->mask);
114                                 smp_cpu_polarization[lcpu] = tl_cpu->pp;
115                         }
116                 }
117         }
118 }
119
120 static void clear_cores(void)
121 {
122         struct core_info *core = &core_info;
123
124         while (core) {
125                 cpus_clear(core->mask);
126                 core = core->next;
127         }
128 }
129
130 static union tl_entry *next_tle(union tl_entry *tle)
131 {
132         if (tle->nl)
133                 return (union tl_entry *)((struct tl_container *)tle + 1);
134         else
135                 return (union tl_entry *)((struct tl_cpu *)tle + 1);
136 }
137
138 static void tl_to_cores(struct tl_info *info)
139 {
140         union tl_entry *tle, *end;
141         struct core_info *core = &core_info;
142
143         spin_lock_irq(&topology_lock);
144         clear_cores();
145         tle = info->tle;
146         end = (union tl_entry *)((unsigned long)info + info->length);
147         while (tle < end) {
148                 switch (tle->nl) {
149                 case 5:
150                 case 4:
151                 case 3:
152                 case 2:
153                         break;
154                 case 1:
155                         core = core->next;
156                         break;
157                 case 0:
158                         add_cpus_to_core(&tle->cpu, core);
159                         break;
160                 default:
161                         clear_cores();
162                         machine_has_topology = 0;
163                         return;
164                 }
165                 tle = next_tle(tle);
166         }
167         spin_unlock_irq(&topology_lock);
168 }
169
170 static void topology_update_polarization_simple(void)
171 {
172         int cpu;
173
174         mutex_lock(&smp_cpu_state_mutex);
175         for_each_possible_cpu(cpu)
176                 smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
177         mutex_unlock(&smp_cpu_state_mutex);
178 }
179
180 static int ptf(unsigned long fc)
181 {
182         int rc;
183
184         asm volatile(
185                 "       .insn   rre,0xb9a20000,%1,%1\n"
186                 "       ipm     %0\n"
187                 "       srl     %0,28\n"
188                 : "=d" (rc)
189                 : "d" (fc)  : "cc");
190         return rc;
191 }
192
193 int topology_set_cpu_management(int fc)
194 {
195         int cpu;
196         int rc;
197
198         if (!machine_has_topology)
199                 return -EOPNOTSUPP;
200         if (fc)
201                 rc = ptf(PTF_VERTICAL);
202         else
203                 rc = ptf(PTF_HORIZONTAL);
204         if (rc)
205                 return -EBUSY;
206         for_each_possible_cpu(cpu)
207                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
208         return rc;
209 }
210
211 static void update_cpu_core_map(void)
212 {
213         int cpu;
214
215         for_each_possible_cpu(cpu)
216                 cpu_core_map[cpu] = cpu_coregroup_map(cpu);
217 }
218
219 int arch_update_cpu_topology(void)
220 {
221         struct tl_info *info = tl_info;
222         struct sys_device *sysdev;
223         int cpu;
224
225         if (!machine_has_topology) {
226                 update_cpu_core_map();
227                 topology_update_polarization_simple();
228                 return 0;
229         }
230         stsi(info, 15, 1, 2);
231         tl_to_cores(info);
232         update_cpu_core_map();
233         for_each_online_cpu(cpu) {
234                 sysdev = get_cpu_sysdev(cpu);
235                 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
236         }
237         return 1;
238 }
239
240 static void topology_work_fn(struct work_struct *work)
241 {
242         rebuild_sched_domains();
243 }
244
245 void topology_schedule_update(void)
246 {
247         schedule_work(&topology_work);
248 }
249
250 static void topology_timer_fn(unsigned long ignored)
251 {
252         if (ptf(PTF_CHECK))
253                 topology_schedule_update();
254         set_topology_timer();
255 }
256
257 static void set_topology_timer(void)
258 {
259         topology_timer.function = topology_timer_fn;
260         topology_timer.data = 0;
261         topology_timer.expires = jiffies + 60 * HZ;
262         add_timer(&topology_timer);
263 }
264
265 static int __init early_parse_topology(char *p)
266 {
267         if (strncmp(p, "on", 2))
268                 return 0;
269         topology_enabled = 1;
270         return 0;
271 }
272 early_param("topology", early_parse_topology);
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         set_topology_timer();
285 out:
286         update_cpu_core_map();
287         return rc;
288 }
289 __initcall(init_topology_update);
290
291 void __init s390_init_cpu_topology(void)
292 {
293         unsigned long long facility_bits;
294         struct tl_info *info;
295         struct core_info *core;
296         int nr_cores;
297         int i;
298
299         if (stfle(&facility_bits, 1) <= 0)
300                 return;
301         if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
302                 return;
303         machine_has_topology = 1;
304
305         tl_info = alloc_bootmem_pages(PAGE_SIZE);
306         info = tl_info;
307         stsi(info, 15, 1, 2);
308
309         nr_cores = info->mag[NR_MAG - 2];
310         for (i = 0; i < info->mnest - 2; i++)
311                 nr_cores *= info->mag[NR_MAG - 3 - i];
312
313         pr_info("The CPU configuration topology of the machine is:");
314         for (i = 0; i < NR_MAG; i++)
315                 printk(" %d", info->mag[i]);
316         printk(" / %d\n", info->mnest);
317
318         core = &core_info;
319         for (i = 0; i < nr_cores; i++) {
320                 core->next = alloc_bootmem(sizeof(struct core_info));
321                 core = core->next;
322                 if (!core)
323                         goto error;
324         }
325         return;
326 error:
327         machine_has_topology = 0;
328 }