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;
  67 static void topology_work_fn(struct work_struct *work);
  68 static struct tl_info *tl_info;
  69 static int machine_has_topology;
  70 static struct timer_list topology_timer;
  71 static void set_topology_timer(void);
  72 static DECLARE_WORK(topology_work, topology_work_fn);
  73 /* topology_lock protects the core linked list */
  74 static DEFINE_SPINLOCK(topology_lock);
  75
  76 static struct mask_info core_info;
  77 cpumask_t cpu_core_map[NR_CPUS];
  78 unsigned char cpu_core_id[NR_CPUS];
  79
  80 #ifdef CONFIG_SCHED_BOOK
  81 static struct mask_info book_info;
  82 cpumask_t cpu_book_map[NR_CPUS];
  83 unsigned char cpu_book_id[NR_CPUS];
  84 #endif
  85
  86 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
  87 {
  88         cpumask_t mask;
  89
  90         cpus_clear(mask);
  91         if (!topology_enabled || !machine_has_topology)
  92                 return cpu_possible_map;
  93         while (info) {
  94                 if (cpu_isset(cpu, info->mask)) {
  95                         mask = info->mask;
  96                         break;
  97                 }
  98                 info = info->next;
  99         }
 100         if (cpus_empty(mask))
 101                 mask = cpumask_of_cpu(cpu);
 102         return mask;
 103 }
 104
 105 static void add_cpus_to_mask(struct tl_cpu *tl_cpu, struct mask_info *book,
 106                              struct mask_info *core)
 107 {
 108         unsigned int cpu;
 109
 110         for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
 111              cpu < CPU_BITS;
 112              cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
 113         {
 114                 unsigned int rcpu, lcpu;
 115
 116                 rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
 117                 for_each_present_cpu(lcpu) {
 118                         if (cpu_logical_map(lcpu) != rcpu)
 119                                 continue;
 120 #ifdef CONFIG_SCHED_BOOK
 121                         cpu_set(lcpu, book->mask);
 122                         cpu_book_id[lcpu] = book->id;
 123 #endif
 124                         cpu_set(lcpu, core->mask);
 125                         cpu_core_id[lcpu] = core->id;
 126                         smp_cpu_polarization[lcpu] = tl_cpu->pp;
 127                 }
 128         }
 129 }
 130
 131 static void clear_masks(void)
 132 {
 133         struct mask_info *info;
 134
 135         info = &core_info;
 136         while (info) {
 137                 cpus_clear(info->mask);
 138                 info = info->next;
 139         }
 140 #ifdef CONFIG_SCHED_BOOK
 141         info = &book_info;
 142         while (info) {
 143                 cpus_clear(info->mask);
 144                 info = info->next;
 145         }
 146 #endif
 147 }
 148
 149 static union tl_entry *next_tle(union tl_entry *tle)
 150 {
 151         if (tle->nl)
 152                 return (union tl_entry *)((struct tl_container *)tle + 1);
 153         else
 154                 return (union tl_entry *)((struct tl_cpu *)tle + 1);
 155 }
 156
 157 static void tl_to_cores(struct tl_info *info)
 158 {
 159 #ifdef CONFIG_SCHED_BOOK
 160         struct mask_info *book = &book_info;
 161 #else
 162         struct mask_info *book = NULL;
 163 #endif
 164         struct mask_info *core = &core_info;
 165         union tl_entry *tle, *end;
 166
 167
 168         spin_lock_irq(&topology_lock);
 169         clear_masks();
 170         tle = info->tle;
 171         end = (union tl_entry *)((unsigned long)info + info->length);
 172         while (tle < end) {
 173                 switch (tle->nl) {
 174 #ifdef CONFIG_SCHED_BOOK
 175                 case 2:
 176                         book = book->next;
 177                         book->id = tle->container.id;
 178                         break;
 179 #endif
 180                 case 1:
 181                         core = core->next;
 182                         core->id = tle->container.id;
 183                         break;
 184                 case 0:
 185                         add_cpus_to_mask(&tle->cpu, book, core);
 186                         break;
 187                 default:
 188                         clear_masks();
 189                         machine_has_topology = 0;
 190                         goto out;
 191                 }
 192                 tle = next_tle(tle);
 193         }
 194 out:
 195         spin_unlock_irq(&topology_lock);
 196 }
 197
 198 static void topology_update_polarization_simple(void)
 199 {
 200         int cpu;
 201
 202         mutex_lock(&smp_cpu_state_mutex);
 203         for_each_possible_cpu(cpu)
 204                 smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
 205         mutex_unlock(&smp_cpu_state_mutex);
 206 }
 207
 208 static int ptf(unsigned long fc)
 209 {
 210         int rc;
 211
 212         asm volatile(
 213                 "       .insn   rre,0xb9a20000,%1,%1\n"
 214                 "       ipm     %0\n"
 215                 "       srl     %0,28\n"
 216                 : "=d" (rc)
 217                 : "d" (fc)  : "cc");
 218         return rc;
 219 }
 220
 221 int topology_set_cpu_management(int fc)
 222 {
 223         int cpu;
 224         int rc;
 225
 226         if (!machine_has_topology)
 227                 return -EOPNOTSUPP;
 228         if (fc)
 229                 rc = ptf(PTF_VERTICAL);
 230         else
 231                 rc = ptf(PTF_HORIZONTAL);
 232         if (rc)
 233                 return -EBUSY;
 234         for_each_possible_cpu(cpu)
 235                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 236         return rc;
 237 }
 238
 239 static void update_cpu_core_map(void)
 240 {
 241         unsigned long flags;
 242         int cpu;
 243
 244         spin_lock_irqsave(&topology_lock, flags);
 245         for_each_possible_cpu(cpu) {
 246                 cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
 247 #ifdef CONFIG_SCHED_BOOK
 248                 cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
 249 #endif
 250         }
 251         spin_unlock_irqrestore(&topology_lock, flags);
 252 }
 253
 254 static void store_topology(struct tl_info *info)
 255 {
 256 #ifdef CONFIG_SCHED_BOOK
 257         int rc;
 258
 259         rc = stsi(info, 15, 1, 3);
 260         if (rc != -ENOSYS)
 261                 return;
 262 #endif
 263         stsi(info, 15, 1, 2);
 264 }
 265
 266 int arch_update_cpu_topology(void)
 267 {
 268         struct tl_info *info = tl_info;
 269         struct sys_device *sysdev;
 270         int cpu;
 271
 272         if (!machine_has_topology) {
 273                 update_cpu_core_map();
 274                 topology_update_polarization_simple();
 275                 return 0;
 276         }
 277         store_topology(info);
 278         tl_to_cores(info);
 279         update_cpu_core_map();
 280         for_each_online_cpu(cpu) {
 281                 sysdev = get_cpu_sysdev(cpu);
 282                 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
 283         }
 284         return 1;
 285 }
 286
 287 static void topology_work_fn(struct work_struct *work)
 288 {
 289         rebuild_sched_domains();
 290 }
 291
 292 void topology_schedule_update(void)
 293 {
 294         schedule_work(&topology_work);
 295 }
 296
 297 static void topology_timer_fn(unsigned long ignored)
 298 {
 299         if (ptf(PTF_CHECK))
 300                 topology_schedule_update();
 301         set_topology_timer();
 302 }
 303
 304 static void set_topology_timer(void)
 305 {
 306         topology_timer.function = topology_timer_fn;
 307         topology_timer.data = 0;
 308         topology_timer.expires = jiffies + 60 * HZ;
 309         add_timer(&topology_timer);
 310 }
 311
 312 static int __init early_parse_topology(char *p)
 313 {
 314         if (strncmp(p, "on", 2))
 315                 return 0;
 316         topology_enabled = 1;
 317         return 0;
 318 }
 319 early_param("topology", early_parse_topology);
 320
 321 static int __init init_topology_update(void)
 322 {
 323         int rc;
 324
 325         rc = 0;
 326         if (!machine_has_topology) {
 327                 topology_update_polarization_simple();
 328                 goto out;
 329         }
 330         init_timer_deferrable(&topology_timer);
 331         set_topology_timer();
 332 out:
 333         update_cpu_core_map();
 334         return rc;
 335 }
 336 __initcall(init_topology_update);
 337
 338 static void alloc_masks(struct tl_info *info, struct mask_info *mask, int offset)
 339 {
 340         int i, nr_masks;
 341
 342         nr_masks = info->mag[NR_MAG - offset];
 343         for (i = 0; i < info->mnest - offset; i++)
 344                 nr_masks *= info->mag[NR_MAG - offset - 1 - i];
 345         nr_masks = max(nr_masks, 1);
 346         for (i = 0; i < nr_masks; i++) {
 347                 mask->next = alloc_bootmem(sizeof(struct mask_info));
 348                 mask = mask->next;
 349         }
 350 }
 351
 352 void __init s390_init_cpu_topology(void)
 353 {
 354         unsigned long long facility_bits;
 355         struct tl_info *info;
 356         int i;
 357
 358         if (stfle(&facility_bits, 1) <= 0)
 359                 return;
 360         if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
 361                 return;
 362         machine_has_topology = 1;
 363
 364         tl_info = alloc_bootmem_pages(PAGE_SIZE);
 365         info = tl_info;
 366         store_topology(info);
 367         pr_info("The CPU configuration topology of the machine is:");
 368         for (i = 0; i < NR_MAG; i++)
 369                 printk(" %d", info->mag[i]);
 370         printk(" / %d\n", info->mnest);
 371         alloc_masks(info, &core_info, 2);
 372 #ifdef CONFIG_SCHED_BOOK
 373         alloc_masks(info, &book_info, 3);
 374 #endif
 375 }