arch/s390/kernel/topology.c

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