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 mask_info {
  61         struct mask_info *next;
  62         unsigned char id;
  63         cpumask_t mask;
  64 };
  65
  66 static int topology_enabled = 1;
  67 static void topology_work_fn(struct work_struct *work);
  68 static struct tl_info *tl_info;
  69 static struct timer_list topology_timer;
  70 static void set_topology_timer(void);
  71 static DECLARE_WORK(topology_work, topology_work_fn);
  72 /* topology_lock protects the core linked list */
  73 static DEFINE_SPINLOCK(topology_lock);
  74
  75 static struct mask_info core_info;
  76 cpumask_t cpu_core_map[NR_CPUS];
  77 unsigned char cpu_core_id[NR_CPUS];
  78
  79 #ifdef CONFIG_SCHED_BOOK
  80 static struct mask_info book_info;
  81 cpumask_t cpu_book_map[NR_CPUS];
  82 unsigned char cpu_book_id[NR_CPUS];
  83 #endif
  84
  85 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
  86 {
  87         cpumask_t mask;
  88
  89         cpus_clear(mask);
  90         if (!topology_enabled || !MACHINE_HAS_TOPOLOGY)
  91                 return cpu_possible_map;
  92         while (info) {
  93                 if (cpu_isset(cpu, info->mask)) {
  94                         mask = info->mask;
  95                         break;
  96                 }
  97                 info = info->next;
  98         }
  99         if (cpus_empty(mask))
 100                 mask = cpumask_of_cpu(cpu);
 101         return mask;
 102 }
 103
 104 static void add_cpus_to_mask(struct tl_cpu *tl_cpu, struct mask_info *book,
 105                              struct mask_info *core)
 106 {
 107         unsigned int cpu;
 108
 109         for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
 110              cpu < CPU_BITS;
 111              cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
 112         {
 113                 unsigned int rcpu, lcpu;
 114
 115                 rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
 116                 for_each_present_cpu(lcpu) {
 117                         if (cpu_logical_map(lcpu) != rcpu)
 118                                 continue;
 119 #ifdef CONFIG_SCHED_BOOK
 120                         cpu_set(lcpu, book->mask);
 121                         cpu_book_id[lcpu] = book->id;
 122 #endif
 123                         cpu_set(lcpu, core->mask);
 124                         cpu_core_id[lcpu] = core->id;
 125                         smp_cpu_polarization[lcpu] = tl_cpu->pp;
 126                 }
 127         }
 128 }
 129
 130 static void clear_masks(void)
 131 {
 132         struct mask_info *info;
 133
 134         info = &core_info;
 135         while (info) {
 136                 cpus_clear(info->mask);
 137                 info = info->next;
 138         }
 139 #ifdef CONFIG_SCHED_BOOK
 140         info = &book_info;
 141         while (info) {
 142                 cpus_clear(info->mask);
 143                 info = info->next;
 144         }
 145 #endif
 146 }
 147
 148 static union tl_entry *next_tle(union tl_entry *tle)
 149 {
 150         if (tle->nl)
 151                 return (union tl_entry *)((struct tl_container *)tle + 1);
 152         else
 153                 return (union tl_entry *)((struct tl_cpu *)tle + 1);
 154 }
 155
 156 static void tl_to_cores(struct tl_info *info)
 157 {
 158 #ifdef CONFIG_SCHED_BOOK
 159         struct mask_info *book = &book_info;
 160 #else
 161         struct mask_info *book = NULL;
 162 #endif
 163         struct mask_info *core = &core_info;
 164         union tl_entry *tle, *end;
 165
 166
 167         spin_lock_irq(&topology_lock);
 168         clear_masks();
 169         tle = info->tle;
 170         end = (union tl_entry *)((unsigned long)info + info->length);
 171         while (tle < end) {
 172                 switch (tle->nl) {
 173 #ifdef CONFIG_SCHED_BOOK
 174                 case 2:
 175                         book = book->next;
 176                         book->id = tle->container.id;
 177                         break;
 178 #endif
 179                 case 1:
 180                         core = core->next;
 181                         core->id = tle->container.id;
 182                         break;
 183                 case 0:
 184                         add_cpus_to_mask(&tle->cpu, book, core);
 185                         break;
 186                 default:
 187                         clear_masks();
 188                         goto out;
 189                 }
 190                 tle = next_tle(tle);
 191         }
 192 out:
 193         spin_unlock_irq(&topology_lock);
 194 }
 195
 196 static void topology_update_polarization_simple(void)
 197 {
 198         int cpu;
 199
 200         mutex_lock(&smp_cpu_state_mutex);
 201         for_each_possible_cpu(cpu)
 202                 smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
 203         mutex_unlock(&smp_cpu_state_mutex);
 204 }
 205
 206 static int ptf(unsigned long fc)
 207 {
 208         int rc;
 209
 210         asm volatile(
 211                 "       .insn   rre,0xb9a20000,%1,%1\n"
 212                 "       ipm     %0\n"
 213                 "       srl     %0,28\n"
 214                 : "=d" (rc)
 215                 : "d" (fc)  : "cc");
 216         return rc;
 217 }
 218
 219 int topology_set_cpu_management(int fc)
 220 {
 221         int cpu;
 222         int rc;
 223
 224         if (!MACHINE_HAS_TOPOLOGY)
 225                 return -EOPNOTSUPP;
 226         if (fc)
 227                 rc = ptf(PTF_VERTICAL);
 228         else
 229                 rc = ptf(PTF_HORIZONTAL);
 230         if (rc)
 231                 return -EBUSY;
 232         for_each_possible_cpu(cpu)
 233                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 234         return rc;
 235 }
 236
 237 static void update_cpu_core_map(void)
 238 {
 239         unsigned long flags;
 240         int cpu;
 241
 242         spin_lock_irqsave(&topology_lock, flags);
 243         for_each_possible_cpu(cpu) {
 244                 cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
 245 #ifdef CONFIG_SCHED_BOOK
 246                 cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
 247 #endif
 248         }
 249         spin_unlock_irqrestore(&topology_lock, flags);
 250 }
 251
 252 static void store_topology(struct tl_info *info)
 253 {
 254 #ifdef CONFIG_SCHED_BOOK
 255         int rc;
 256
 257         rc = stsi(info, 15, 1, 3);
 258         if (rc != -ENOSYS)
 259                 return;
 260 #endif
 261         stsi(info, 15, 1, 2);
 262 }
 263
 264 int arch_update_cpu_topology(void)
 265 {
 266         struct tl_info *info = tl_info;
 267         struct sys_device *sysdev;
 268         int cpu;
 269
 270         if (!MACHINE_HAS_TOPOLOGY) {
 271                 update_cpu_core_map();
 272                 topology_update_polarization_simple();
 273                 return 0;
 274         }
 275         store_topology(info);
 276         tl_to_cores(info);
 277         update_cpu_core_map();
 278         for_each_online_cpu(cpu) {
 279                 sysdev = get_cpu_sysdev(cpu);
 280                 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
 281         }
 282         return 1;
 283 }
 284
 285 static void topology_work_fn(struct work_struct *work)
 286 {
 287         rebuild_sched_domains();
 288 }
 289
 290 void topology_schedule_update(void)
 291 {
 292         schedule_work(&topology_work);
 293 }
 294
 295 static void topology_timer_fn(unsigned long ignored)
 296 {
 297         if (ptf(PTF_CHECK))
 298                 topology_schedule_update();
 299         set_topology_timer();
 300 }
 301
 302 static void set_topology_timer(void)
 303 {
 304         topology_timer.function = topology_timer_fn;
 305         topology_timer.data = 0;
 306         topology_timer.expires = jiffies + 60 * HZ;
 307         add_timer(&topology_timer);
 308 }
 309
 310 static int __init early_parse_topology(char *p)
 311 {
 312         if (strncmp(p, "off", 3))
 313                 return 0;
 314         topology_enabled = 0;
 315         return 0;
 316 }
 317 early_param("topology", early_parse_topology);
 318
 319 static int __init init_topology_update(void)
 320 {
 321         int rc;
 322
 323         rc = 0;
 324         if (!MACHINE_HAS_TOPOLOGY) {
 325                 topology_update_polarization_simple();
 326                 goto out;
 327         }
 328         init_timer_deferrable(&topology_timer);
 329         set_topology_timer();
 330 out:
 331         update_cpu_core_map();
 332         return rc;
 333 }
 334 __initcall(init_topology_update);
 335
 336 static void alloc_masks(struct tl_info *info, struct mask_info *mask, int offset)
 337 {
 338         int i, nr_masks;
 339
 340         nr_masks = info->mag[NR_MAG - offset];
 341         for (i = 0; i < info->mnest - offset; i++)
 342                 nr_masks *= info->mag[NR_MAG - offset - 1 - i];
 343         nr_masks = max(nr_masks, 1);
 344         for (i = 0; i < nr_masks; i++) {
 345                 mask->next = alloc_bootmem(sizeof(struct mask_info));
 346                 mask = mask->next;
 347         }
 348 }
 349
 350 void __init s390_init_cpu_topology(void)
 351 {
 352         struct tl_info *info;
 353         int i;
 354
 355         if (!MACHINE_HAS_TOPOLOGY)
 356                 return;
 357         tl_info = alloc_bootmem_pages(PAGE_SIZE);
 358         info = tl_info;
 359         store_topology(info);
 360         pr_info("The CPU configuration topology of the machine is:");
 361         for (i = 0; i < NR_MAG; i++)
 362                 printk(" %d", info->mag[i]);
 363         printk(" / %d\n", info->mnest);
 364         alloc_masks(info, &core_info, 2);
 365 #ifdef CONFIG_SCHED_BOOK
 366         alloc_masks(info, &book_info, 3);
 367 #endif
 368 }