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