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