arch/s390/kernel/topology.c

   1 /*
   2  *    Copyright IBM Corp. 2007
   3  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
   4  */
   5
   6 #include <linux/kernel.h>
   7 #include <linux/mm.h>
   8 #include <linux/init.h>
   9 #include <linux/device.h>
  10 #include <linux/bootmem.h>
  11 #include <linux/sched.h>
  12 #include <linux/workqueue.h>
  13 #include <linux/cpu.h>
  14 #include <linux/smp.h>
  15 #include <linux/cpuset.h>
  16 #include <asm/delay.h>
  17 #include <asm/s390_ext.h>
  18 #include <asm/sysinfo.h>
  19
  20 #define CPU_BITS 64
  21 #define NR_MAG 6
  22
  23 #define PTF_HORIZONTAL  (0UL)
  24 #define PTF_VERTICAL    (1UL)
  25 #define PTF_CHECK       (2UL)
  26
  27 struct tl_cpu {
  28         unsigned char reserved0[4];
  29         unsigned char :6;
  30         unsigned char pp:2;
  31         unsigned char reserved1;
  32         unsigned short origin;
  33         unsigned long mask[CPU_BITS / BITS_PER_LONG];
  34 };
  35
  36 struct tl_container {
  37         unsigned char reserved[8];
  38 };
  39
  40 union tl_entry {
  41         unsigned char nl;
  42         struct tl_cpu cpu;
  43         struct tl_container container;
  44 };
  45
  46 struct tl_info {
  47         unsigned char reserved0[2];
  48         unsigned short length;
  49         unsigned char mag[NR_MAG];
  50         unsigned char reserved1;
  51         unsigned char mnest;
  52         unsigned char reserved2[4];
  53         union tl_entry tle[0];
  54 };
  55
  56 struct core_info {
  57         struct core_info *next;
  58         cpumask_t mask;
  59 };
  60
  61 static int topology_enabled;
  62 static void topology_work_fn(struct work_struct *work);
  63 static struct tl_info *tl_info;
  64 static struct core_info core_info;
  65 static int machine_has_topology;
  66 static int machine_has_topology_irq;
  67 static struct timer_list topology_timer;
  68 static void set_topology_timer(void);
  69 static DECLARE_WORK(topology_work, topology_work_fn);
  70 /* topology_lock protects the core linked list */
  71 static DEFINE_SPINLOCK(topology_lock);
  72
  73 cpumask_t cpu_core_map[NR_CPUS];
  74
  75 cpumask_t cpu_coregroup_map(unsigned int cpu)
  76 {
  77         struct core_info *core = &core_info;
  78         unsigned long flags;
  79         cpumask_t mask;
  80
  81         cpus_clear(mask);
  82         if (!topology_enabled || !machine_has_topology)
  83                 return cpu_possible_map;
  84         spin_lock_irqsave(&topology_lock, flags);
  85         while (core) {
  86                 if (cpu_isset(cpu, core->mask)) {
  87                         mask = core->mask;
  88                         break;
  89                 }
  90                 core = core->next;
  91         }
  92         spin_unlock_irqrestore(&topology_lock, flags);
  93         if (cpus_empty(mask))
  94                 mask = cpumask_of_cpu(cpu);
  95         return mask;
  96 }
  97
  98 static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
  99 {
 100         unsigned int cpu;
 101
 102         for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
 103              cpu < CPU_BITS;
 104              cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
 105         {
 106                 unsigned int rcpu, lcpu;
 107
 108                 rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
 109                 for_each_present_cpu(lcpu) {
 110                         if (__cpu_logical_map[lcpu] == rcpu) {
 111                                 cpu_set(lcpu, core->mask);
 112                                 smp_cpu_polarization[lcpu] = tl_cpu->pp;
 113                         }
 114                 }
 115         }
 116 }
 117
 118 static void clear_cores(void)
 119 {
 120         struct core_info *core = &core_info;
 121
 122         while (core) {
 123                 cpus_clear(core->mask);
 124                 core = core->next;
 125         }
 126 }
 127
 128 static union tl_entry *next_tle(union tl_entry *tle)
 129 {
 130         if (tle->nl)
 131                 return (union tl_entry *)((struct tl_container *)tle + 1);
 132         else
 133                 return (union tl_entry *)((struct tl_cpu *)tle + 1);
 134 }
 135
 136 static void tl_to_cores(struct tl_info *info)
 137 {
 138         union tl_entry *tle, *end;
 139         struct core_info *core = &core_info;
 140
 141         spin_lock_irq(&topology_lock);
 142         clear_cores();
 143         tle = info->tle;
 144         end = (union tl_entry *)((unsigned long)info + info->length);
 145         while (tle < end) {
 146                 switch (tle->nl) {
 147                 case 5:
 148                 case 4:
 149                 case 3:
 150                 case 2:
 151                         break;
 152                 case 1:
 153                         core = core->next;
 154                         break;
 155                 case 0:
 156                         add_cpus_to_core(&tle->cpu, core);
 157                         break;
 158                 default:
 159                         clear_cores();
 160                         machine_has_topology = 0;
 161                         return;
 162                 }
 163                 tle = next_tle(tle);
 164         }
 165         spin_unlock_irq(&topology_lock);
 166 }
 167
 168 static void topology_update_polarization_simple(void)
 169 {
 170         int cpu;
 171
 172         mutex_lock(&smp_cpu_state_mutex);
 173         for_each_possible_cpu(cpu)
 174                 smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
 175         mutex_unlock(&smp_cpu_state_mutex);
 176 }
 177
 178 static int ptf(unsigned long fc)
 179 {
 180         int rc;
 181
 182         asm volatile(
 183                 "       .insn   rre,0xb9a20000,%1,%1\n"
 184                 "       ipm     %0\n"
 185                 "       srl     %0,28\n"
 186                 : "=d" (rc)
 187                 : "d" (fc)  : "cc");
 188         return rc;
 189 }
 190
 191 int topology_set_cpu_management(int fc)
 192 {
 193         int cpu;
 194         int rc;
 195
 196         if (!machine_has_topology)
 197                 return -EOPNOTSUPP;
 198         if (fc)
 199                 rc = ptf(PTF_VERTICAL);
 200         else
 201                 rc = ptf(PTF_HORIZONTAL);
 202         if (rc)
 203                 return -EBUSY;
 204         for_each_possible_cpu(cpu)
 205                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 206         return rc;
 207 }
 208
 209 static void update_cpu_core_map(void)
 210 {
 211         int cpu;
 212
 213         for_each_possible_cpu(cpu)
 214                 cpu_core_map[cpu] = cpu_coregroup_map(cpu);
 215 }
 216
 217 void arch_update_cpu_topology(void)
 218 {
 219         struct tl_info *info = tl_info;
 220         struct sys_device *sysdev;
 221         int cpu;
 222
 223         if (!machine_has_topology) {
 224                 update_cpu_core_map();
 225                 topology_update_polarization_simple();
 226                 return;
 227         }
 228         stsi(info, 15, 1, 2);
 229         tl_to_cores(info);
 230         update_cpu_core_map();
 231         for_each_online_cpu(cpu) {
 232                 sysdev = get_cpu_sysdev(cpu);
 233                 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
 234         }
 235 }
 236
 237 static void topology_work_fn(struct work_struct *work)
 238 {
 239         rebuild_sched_domains();
 240 }
 241
 242 void topology_schedule_update(void)
 243 {
 244         schedule_work(&topology_work);
 245 }
 246
 247 static void topology_timer_fn(unsigned long ignored)
 248 {
 249         if (ptf(PTF_CHECK))
 250                 topology_schedule_update();
 251         set_topology_timer();
 252 }
 253
 254 static void set_topology_timer(void)
 255 {
 256         topology_timer.function = topology_timer_fn;
 257         topology_timer.data = 0;
 258         topology_timer.expires = jiffies + 60 * HZ;
 259         add_timer(&topology_timer);
 260 }
 261
 262 static void topology_interrupt(__u16 code)
 263 {
 264         schedule_work(&topology_work);
 265 }
 266
 267 static int __init early_parse_topology(char *p)
 268 {
 269         if (strncmp(p, "on", 2))
 270                 return 0;
 271         topology_enabled = 1;
 272         return 0;
 273 }
 274 early_param("topology", early_parse_topology);
 275
 276 static int __init init_topology_update(void)
 277 {
 278         int rc;
 279
 280         rc = 0;
 281         if (!machine_has_topology) {
 282                 topology_update_polarization_simple();
 283                 goto out;
 284         }
 285         init_timer_deferrable(&topology_timer);
 286         if (machine_has_topology_irq) {
 287                 rc = register_external_interrupt(0x2005, topology_interrupt);
 288                 if (rc)
 289                         goto out;
 290                 ctl_set_bit(0, 8);
 291         }
 292         else
 293                 set_topology_timer();
 294 out:
 295         update_cpu_core_map();
 296         return rc;
 297 }
 298 __initcall(init_topology_update);
 299
 300 void __init s390_init_cpu_topology(void)
 301 {
 302         unsigned long long facility_bits;
 303         struct tl_info *info;
 304         struct core_info *core;
 305         int nr_cores;
 306         int i;
 307
 308         if (stfle(&facility_bits, 1) <= 0)
 309                 return;
 310         if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
 311                 return;
 312         machine_has_topology = 1;
 313
 314         if (facility_bits & (1ULL << 51))
 315                 machine_has_topology_irq = 1;
 316
 317         tl_info = alloc_bootmem_pages(PAGE_SIZE);
 318         info = tl_info;
 319         stsi(info, 15, 1, 2);
 320
 321         nr_cores = info->mag[NR_MAG - 2];
 322         for (i = 0; i < info->mnest - 2; i++)
 323                 nr_cores *= info->mag[NR_MAG - 3 - i];
 324
 325         printk(KERN_INFO "CPU topology:");
 326         for (i = 0; i < NR_MAG; i++)
 327                 printk(" %d", info->mag[i]);
 328         printk(" / %d\n", info->mnest);
 329
 330         core = &core_info;
 331         for (i = 0; i < nr_cores; i++) {
 332                 core->next = alloc_bootmem(sizeof(struct core_info));
 333                 core = core->next;
 334                 if (!core)
 335                         goto error;
 336         }
 337         return;
 338 error:
 339         machine_has_topology = 0;
 340         machine_has_topology_irq = 0;
 341 }