linux/arch/s390/kernel/topology.c
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   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
  26struct 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
  35struct tl_container {
  36        unsigned char reserved[8];
  37};
  38
  39union tl_entry {
  40        unsigned char nl;
  41        struct tl_cpu cpu;
  42        struct tl_container container;
  43};
  44
  45struct 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
  55struct core_info {
  56        struct core_info *next;
  57        cpumask_t mask;
  58};
  59
  60static void topology_work_fn(struct work_struct *work);
  61static struct tl_info *tl_info;
  62static struct core_info core_info;
  63static int machine_has_topology;
  64static int machine_has_topology_irq;
  65static struct timer_list topology_timer;
  66static void set_topology_timer(void);
  67static DECLARE_WORK(topology_work, topology_work_fn);
  68/* topology_lock protects the core linked list */
  69static DEFINE_SPINLOCK(topology_lock);
  70
  71cpumask_t cpu_core_map[NR_CPUS];
  72
  73cpumask_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
  96static 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
 116static 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
 126static 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
 134static 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
 166static 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
 176static 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
 189int 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
 207static 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
 215void 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
 235static void topology_work_fn(struct work_struct *work)
 236{
 237        arch_reinit_sched_domains();
 238}
 239
 240void topology_schedule_update(void)
 241{
 242        schedule_work(&topology_work);
 243}
 244
 245static void topology_timer_fn(unsigned long ignored)
 246{
 247        if (ptf(PTF_CHECK))
 248                topology_schedule_update();
 249        set_topology_timer();
 250}
 251
 252static 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
 260static void topology_interrupt(__u16 code)
 261{
 262        schedule_work(&topology_work);
 263}
 264
 265static 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();
 283out:
 284        update_cpu_core_map();
 285        return rc;
 286}
 287__initcall(init_topology_update);
 288
 289void __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;
 327error:
 328        machine_has_topology = 0;
 329        machine_has_topology_irq = 0;
 330}
 331