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
  21 #define PTF_HORIZONTAL  (0UL)
  22 #define PTF_VERTICAL    (1UL)
  23 #define PTF_CHECK       (2UL)
  24
  25 struct mask_info {
  26         struct mask_info *next;
  27         unsigned char id;
  28         cpumask_t mask;
  29 };
  30
  31 static int topology_enabled = 1;
  32 static void topology_work_fn(struct work_struct *work);
  33 static struct sysinfo_15_1_x *tl_info;
  34 static struct timer_list topology_timer;
  35 static void set_topology_timer(void);
  36 static DECLARE_WORK(topology_work, topology_work_fn);
  37 /* topology_lock protects the core linked list */
  38 static DEFINE_SPINLOCK(topology_lock);
  39
  40 static struct mask_info core_info;
  41 cpumask_t cpu_core_map[NR_CPUS];
  42 unsigned char cpu_core_id[NR_CPUS];
  43
  44 #ifdef CONFIG_SCHED_BOOK
  45 static struct mask_info book_info;
  46 cpumask_t cpu_book_map[NR_CPUS];
  47 unsigned char cpu_book_id[NR_CPUS];
  48 #endif
  49
  50 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
  51 {
  52         cpumask_t mask;
  53
  54         cpumask_clear(&mask);
  55         if (!topology_enabled || !MACHINE_HAS_TOPOLOGY) {
  56                 cpumask_copy(&mask, cpumask_of(cpu));
  57                 return mask;
  58         }
  59         while (info) {
  60                 if (cpumask_test_cpu(cpu, &info->mask)) {
  61                         mask = info->mask;
  62                         break;
  63                 }
  64                 info = info->next;
  65         }
  66         if (cpumask_empty(&mask))
  67                 cpumask_copy(&mask, cpumask_of(cpu));
  68         return mask;
  69 }
  70
  71 static void add_cpus_to_mask(struct topology_cpu *tl_cpu,
  72                              struct mask_info *book, struct mask_info *core)
  73 {
  74         unsigned int cpu;
  75
  76         for (cpu = find_first_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS);
  77              cpu < TOPOLOGY_CPU_BITS;
  78              cpu = find_next_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS, cpu + 1))
  79         {
  80                 unsigned int rcpu, lcpu;
  81
  82                 rcpu = TOPOLOGY_CPU_BITS - 1 - cpu + tl_cpu->origin;
  83                 for_each_present_cpu(lcpu) {
  84                         if (cpu_logical_map(lcpu) != rcpu)
  85                                 continue;
  86 #ifdef CONFIG_SCHED_BOOK
  87                         cpumask_set_cpu(lcpu, &book->mask);
  88                         cpu_book_id[lcpu] = book->id;
  89 #endif
  90                         cpumask_set_cpu(lcpu, &core->mask);
  91                         cpu_core_id[lcpu] = core->id;
  92                         smp_cpu_polarization[lcpu] = tl_cpu->pp;
  93                 }
  94         }
  95 }
  96
  97 static void clear_masks(void)
  98 {
  99         struct mask_info *info;
 100
 101         info = &core_info;
 102         while (info) {
 103                 cpumask_clear(&info->mask);
 104                 info = info->next;
 105         }
 106 #ifdef CONFIG_SCHED_BOOK
 107         info = &book_info;
 108         while (info) {
 109                 cpumask_clear(&info->mask);
 110                 info = info->next;
 111         }
 112 #endif
 113 }
 114
 115 static union topology_entry *next_tle(union topology_entry *tle)
 116 {
 117         if (!tle->nl)
 118                 return (union topology_entry *)((struct topology_cpu *)tle + 1);
 119         return (union topology_entry *)((struct topology_container *)tle + 1);
 120 }
 121
 122 static void tl_to_cores(struct sysinfo_15_1_x *info)
 123 {
 124 #ifdef CONFIG_SCHED_BOOK
 125         struct mask_info *book = &book_info;
 126 #else
 127         struct mask_info *book = NULL;
 128 #endif
 129         struct mask_info *core = &core_info;
 130         union topology_entry *tle, *end;
 131
 132
 133         spin_lock_irq(&topology_lock);
 134         clear_masks();
 135         tle = info->tle;
 136         end = (union topology_entry *)((unsigned long)info + info->length);
 137         while (tle < end) {
 138                 switch (tle->nl) {
 139 #ifdef CONFIG_SCHED_BOOK
 140                 case 2:
 141                         book = book->next;
 142                         book->id = tle->container.id;
 143                         break;
 144 #endif
 145                 case 1:
 146                         core = core->next;
 147                         core->id = tle->container.id;
 148                         break;
 149                 case 0:
 150                         add_cpus_to_mask(&tle->cpu, book, core);
 151                         break;
 152                 default:
 153                         clear_masks();
 154                         goto out;
 155                 }
 156                 tle = next_tle(tle);
 157         }
 158 out:
 159         spin_unlock_irq(&topology_lock);
 160 }
 161
 162 static void topology_update_polarization_simple(void)
 163 {
 164         int cpu;
 165
 166         mutex_lock(&smp_cpu_state_mutex);
 167         for_each_possible_cpu(cpu)
 168                 smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
 169         mutex_unlock(&smp_cpu_state_mutex);
 170 }
 171
 172 static int ptf(unsigned long fc)
 173 {
 174         int rc;
 175
 176         asm volatile(
 177                 "       .insn   rre,0xb9a20000,%1,%1\n"
 178                 "       ipm     %0\n"
 179                 "       srl     %0,28\n"
 180                 : "=d" (rc)
 181                 : "d" (fc)  : "cc");
 182         return rc;
 183 }
 184
 185 int topology_set_cpu_management(int fc)
 186 {
 187         int cpu;
 188         int rc;
 189
 190         if (!MACHINE_HAS_TOPOLOGY)
 191                 return -EOPNOTSUPP;
 192         if (fc)
 193                 rc = ptf(PTF_VERTICAL);
 194         else
 195                 rc = ptf(PTF_HORIZONTAL);
 196         if (rc)
 197                 return -EBUSY;
 198         for_each_possible_cpu(cpu)
 199                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 200         return rc;
 201 }
 202
 203 static void update_cpu_core_map(void)
 204 {
 205         unsigned long flags;
 206         int cpu;
 207
 208         spin_lock_irqsave(&topology_lock, flags);
 209         for_each_possible_cpu(cpu) {
 210                 cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
 211 #ifdef CONFIG_SCHED_BOOK
 212                 cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
 213 #endif
 214         }
 215         spin_unlock_irqrestore(&topology_lock, flags);
 216 }
 217
 218 void store_topology(struct sysinfo_15_1_x *info)
 219 {
 220 #ifdef CONFIG_SCHED_BOOK
 221         int rc;
 222
 223         rc = stsi(info, 15, 1, 3);
 224         if (rc != -ENOSYS)
 225                 return;
 226 #endif
 227         stsi(info, 15, 1, 2);
 228 }
 229
 230 int arch_update_cpu_topology(void)
 231 {
 232         struct sysinfo_15_1_x *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         store_topology(info);
 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, "off", 3))
 279                 return 0;
 280         topology_enabled = 0;
 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 static void __init alloc_masks(struct sysinfo_15_1_x *info,
 303                                struct mask_info *mask, int offset)
 304 {
 305         int i, nr_masks;
 306
 307         nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
 308         for (i = 0; i < info->mnest - offset; i++)
 309                 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
 310         nr_masks = max(nr_masks, 1);
 311         for (i = 0; i < nr_masks; i++) {
 312                 mask->next = alloc_bootmem(sizeof(struct mask_info));
 313                 mask = mask->next;
 314         }
 315 }
 316
 317 void __init s390_init_cpu_topology(void)
 318 {
 319         struct sysinfo_15_1_x *info;
 320         int i;
 321
 322         if (!MACHINE_HAS_TOPOLOGY)
 323                 return;
 324         tl_info = alloc_bootmem_pages(PAGE_SIZE);
 325         info = tl_info;
 326         store_topology(info);
 327         pr_info("The CPU configuration topology of the machine is:");
 328         for (i = 0; i < TOPOLOGY_NR_MAG; i++)
 329                 printk(" %d", info->mag[i]);
 330         printk(" / %d\n", info->mnest);
 331         alloc_masks(info, &core_info, 2);
 332 #ifdef CONFIG_SCHED_BOOK
 333         alloc_masks(info, &book_info, 3);
 334 #endif
 335 }