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 const struct cpumask *cpu_coregroup_mask(unsigned int cpu)
  97 {
  98         return &cpu_core_map[cpu];
  99 }
 100
 101 static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
 102 {
 103         unsigned int cpu;
 104
 105         for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
 106              cpu < CPU_BITS;
 107              cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
 108         {
 109                 unsigned int rcpu, lcpu;
 110
 111                 rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
 112                 for_each_present_cpu(lcpu) {
 113                         if (__cpu_logical_map[lcpu] == rcpu) {
 114                                 cpu_set(lcpu, core->mask);
 115                                 smp_cpu_polarization[lcpu] = tl_cpu->pp;
 116                         }
 117                 }
 118         }
 119 }
 120
 121 static void clear_cores(void)
 122 {
 123         struct core_info *core = &core_info;
 124
 125         while (core) {
 126                 cpus_clear(core->mask);
 127                 core = core->next;
 128         }
 129 }
 130
 131 static union tl_entry *next_tle(union tl_entry *tle)
 132 {
 133         if (tle->nl)
 134                 return (union tl_entry *)((struct tl_container *)tle + 1);
 135         else
 136                 return (union tl_entry *)((struct tl_cpu *)tle + 1);
 137 }
 138
 139 static void tl_to_cores(struct tl_info *info)
 140 {
 141         union tl_entry *tle, *end;
 142         struct core_info *core = &core_info;
 143
 144         spin_lock_irq(&topology_lock);
 145         clear_cores();
 146         tle = info->tle;
 147         end = (union tl_entry *)((unsigned long)info + info->length);
 148         while (tle < end) {
 149                 switch (tle->nl) {
 150                 case 5:
 151                 case 4:
 152                 case 3:
 153                 case 2:
 154                         break;
 155                 case 1:
 156                         core = core->next;
 157                         break;
 158                 case 0:
 159                         add_cpus_to_core(&tle->cpu, core);
 160                         break;
 161                 default:
 162                         clear_cores();
 163                         machine_has_topology = 0;
 164                         return;
 165                 }
 166                 tle = next_tle(tle);
 167         }
 168         spin_unlock_irq(&topology_lock);
 169 }
 170
 171 static void topology_update_polarization_simple(void)
 172 {
 173         int cpu;
 174
 175         mutex_lock(&smp_cpu_state_mutex);
 176         for_each_present_cpu(cpu)
 177                 smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
 178         mutex_unlock(&smp_cpu_state_mutex);
 179 }
 180
 181 static int ptf(unsigned long fc)
 182 {
 183         int rc;
 184
 185         asm volatile(
 186                 "       .insn   rre,0xb9a20000,%1,%1\n"
 187                 "       ipm     %0\n"
 188                 "       srl     %0,28\n"
 189                 : "=d" (rc)
 190                 : "d" (fc)  : "cc");
 191         return rc;
 192 }
 193
 194 int topology_set_cpu_management(int fc)
 195 {
 196         int cpu;
 197         int rc;
 198
 199         if (!machine_has_topology)
 200                 return -EOPNOTSUPP;
 201         if (fc)
 202                 rc = ptf(PTF_VERTICAL);
 203         else
 204                 rc = ptf(PTF_HORIZONTAL);
 205         if (rc)
 206                 return -EBUSY;
 207         for_each_present_cpu(cpu)
 208                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 209         return rc;
 210 }
 211
 212 static void update_cpu_core_map(void)
 213 {
 214         int cpu;
 215
 216         for_each_present_cpu(cpu)
 217                 cpu_core_map[cpu] = cpu_coregroup_map(cpu);
 218 }
 219
 220 void arch_update_cpu_topology(void)
 221 {
 222         struct tl_info *info = tl_info;
 223         struct sys_device *sysdev;
 224         int cpu;
 225
 226         if (!machine_has_topology) {
 227                 update_cpu_core_map();
 228                 topology_update_polarization_simple();
 229                 return;
 230         }
 231         stsi(info, 15, 1, 2);
 232         tl_to_cores(info);
 233         update_cpu_core_map();
 234         for_each_online_cpu(cpu) {
 235                 sysdev = get_cpu_sysdev(cpu);
 236                 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
 237         }
 238 }
 239
 240 static void topology_work_fn(struct work_struct *work)
 241 {
 242         arch_reinit_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 void topology_interrupt(__u16 code)
 266 {
 267         schedule_work(&topology_work);
 268 }
 269
 270 static int __init init_topology_update(void)
 271 {
 272         int rc;
 273
 274         rc = 0;
 275         if (!machine_has_topology) {
 276                 topology_update_polarization_simple();
 277                 goto out;
 278         }
 279         init_timer_deferrable(&topology_timer);
 280         if (machine_has_topology_irq) {
 281                 rc = register_external_interrupt(0x2005, topology_interrupt);
 282                 if (rc)
 283                         goto out;
 284                 ctl_set_bit(0, 8);
 285         }
 286         else
 287                 set_topology_timer();
 288 out:
 289         update_cpu_core_map();
 290         return rc;
 291 }
 292 __initcall(init_topology_update);
 293
 294 void __init s390_init_cpu_topology(void)
 295 {
 296         unsigned long long facility_bits;
 297         struct tl_info *info;
 298         struct core_info *core;
 299         int nr_cores;
 300         int i;
 301
 302         if (stfle(&facility_bits, 1) <= 0)
 303                 return;
 304         if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
 305                 return;
 306         machine_has_topology = 1;
 307
 308         if (facility_bits & (1ULL << 51))
 309                 machine_has_topology_irq = 1;
 310
 311         tl_info = alloc_bootmem_pages(PAGE_SIZE);
 312         info = tl_info;
 313         stsi(info, 15, 1, 2);
 314
 315         nr_cores = info->mag[NR_MAG - 2];
 316         for (i = 0; i < info->mnest - 2; i++)
 317                 nr_cores *= info->mag[NR_MAG - 3 - i];
 318
 319         printk(KERN_INFO "CPU topology:");
 320         for (i = 0; i < NR_MAG; i++)
 321                 printk(" %d", info->mag[i]);
 322         printk(" / %d\n", info->mnest);
 323
 324         core = &core_info;
 325         for (i = 0; i < nr_cores; i++) {
 326                 core->next = alloc_bootmem(sizeof(struct core_info));
 327                 core = core->next;
 328                 if (!core)
 329                         goto error;
 330         }
 331         return;
 332 error:
 333         machine_has_topology = 0;
 334         machine_has_topology_irq = 0;
 335 }