git.oblomov.eu Git - linux-2.6/blob - 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 }