arch/s390/kernel/topology.c

   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
  26 struct 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
  35 struct tl_container {
  36         unsigned char reserved[8];
  37 };
  38
  39 union tl_entry {
  40         unsigned char nl;
  41         struct tl_cpu cpu;
  42         struct tl_container container;
  43 };
  44
  45 struct 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
  55 struct core_info {
  56         struct core_info *next;
  57         cpumask_t mask;
  58 };
  59
  60 static void topology_work_fn(struct work_struct *work);
  61 static struct tl_info *tl_info;
  62 static struct core_info core_info;
  63 static int machine_has_topology;
  64 static int machine_has_topology_irq;
  65 static struct timer_list topology_timer;
  66 static void set_topology_timer(void);
  67 static DECLARE_WORK(topology_work, topology_work_fn);
  68
  69 cpumask_t cpu_coregroup_map(unsigned int cpu)
  70 {
  71         struct core_info *core = &core_info;
  72         cpumask_t mask;
  73
  74         cpus_clear(mask);
  75         if (!machine_has_topology)
  76                 return cpu_present_map;
  77         mutex_lock(&smp_cpu_state_mutex);
  78         while (core) {
  79                 if (cpu_isset(cpu, core->mask)) {
  80                         mask = core->mask;
  81                         break;
  82                 }
  83                 core = core->next;
  84         }
  85         mutex_unlock(&smp_cpu_state_mutex);
  86         if (cpus_empty(mask))
  87                 mask = cpumask_of_cpu(cpu);
  88         return mask;
  89 }
  90
  91 static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
  92 {
  93         unsigned int cpu;
  94
  95         for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
  96              cpu < CPU_BITS;
  97              cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
  98         {
  99                 unsigned int rcpu, lcpu;
 100
 101                 rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
 102                 for_each_present_cpu(lcpu) {
 103                         if (__cpu_logical_map[lcpu] == rcpu) {
 104                                 cpu_set(lcpu, core->mask);
 105                                 smp_cpu_polarization[lcpu] = tl_cpu->pp;
 106                         }
 107                 }
 108         }
 109 }
 110
 111 static void clear_cores(void)
 112 {
 113         struct core_info *core = &core_info;
 114
 115         while (core) {
 116                 cpus_clear(core->mask);
 117                 core = core->next;
 118         }
 119 }
 120
 121 static union tl_entry *next_tle(union tl_entry *tle)
 122 {
 123         if (tle->nl)
 124                 return (union tl_entry *)((struct tl_container *)tle + 1);
 125         else
 126                 return (union tl_entry *)((struct tl_cpu *)tle + 1);
 127 }
 128
 129 static void tl_to_cores(struct tl_info *info)
 130 {
 131         union tl_entry *tle, *end;
 132         struct core_info *core = &core_info;
 133
 134         mutex_lock(&smp_cpu_state_mutex);
 135         clear_cores();
 136         tle = info->tle;
 137         end = (union tl_entry *)((unsigned long)info + info->length);
 138         while (tle < end) {
 139                 switch (tle->nl) {
 140                 case 5:
 141                 case 4:
 142                 case 3:
 143                 case 2:
 144                         break;
 145                 case 1:
 146                         core = core->next;
 147                         break;
 148                 case 0:
 149                         add_cpus_to_core(&tle->cpu, core);
 150                         break;
 151                 default:
 152                         clear_cores();
 153                         machine_has_topology = 0;
 154                         return;
 155                 }
 156                 tle = next_tle(tle);
 157         }
 158         mutex_unlock(&smp_cpu_state_mutex);
 159 }
 160
 161 static void topology_update_polarization_simple(void)
 162 {
 163         int cpu;
 164
 165         mutex_lock(&smp_cpu_state_mutex);
 166         for_each_present_cpu(cpu)
 167                 smp_cpu_polarization[cpu] = POLARIZATION_HRZ;
 168         mutex_unlock(&smp_cpu_state_mutex);
 169 }
 170
 171 static int ptf(unsigned long fc)
 172 {
 173         int rc;
 174
 175         asm volatile(
 176                 "       .insn   rre,0xb9a20000,%1,%1\n"
 177                 "       ipm     %0\n"
 178                 "       srl     %0,28\n"
 179                 : "=d" (rc)
 180                 : "d" (fc)  : "cc");
 181         return rc;
 182 }
 183
 184 int topology_set_cpu_management(int fc)
 185 {
 186         int cpu;
 187         int rc;
 188
 189         if (!machine_has_topology)
 190                 return -EOPNOTSUPP;
 191         if (fc)
 192                 rc = ptf(PTF_VERTICAL);
 193         else
 194                 rc = ptf(PTF_HORIZONTAL);
 195         if (rc)
 196                 return -EBUSY;
 197         for_each_present_cpu(cpu)
 198                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 199         return rc;
 200 }
 201
 202 void arch_update_cpu_topology(void)
 203 {
 204         struct tl_info *info = tl_info;
 205         struct sys_device *sysdev;
 206         int cpu;
 207
 208         if (!machine_has_topology) {
 209                 topology_update_polarization_simple();
 210                 return;
 211         }
 212         stsi(info, 15, 1, 2);
 213         tl_to_cores(info);
 214         for_each_online_cpu(cpu) {
 215                 sysdev = get_cpu_sysdev(cpu);
 216                 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
 217         }
 218 }
 219
 220 static void topology_work_fn(struct work_struct *work)
 221 {
 222         arch_reinit_sched_domains();
 223 }
 224
 225 void topology_schedule_update(void)
 226 {
 227         schedule_work(&topology_work);
 228 }
 229
 230 static void topology_timer_fn(unsigned long ignored)
 231 {
 232         if (ptf(PTF_CHECK))
 233                 topology_schedule_update();
 234         set_topology_timer();
 235 }
 236
 237 static void set_topology_timer(void)
 238 {
 239         topology_timer.function = topology_timer_fn;
 240         topology_timer.data = 0;
 241         topology_timer.expires = jiffies + 60 * HZ;
 242         add_timer(&topology_timer);
 243 }
 244
 245 static void topology_interrupt(__u16 code)
 246 {
 247         schedule_work(&topology_work);
 248 }
 249
 250 static int __init init_topology_update(void)
 251 {
 252         int rc;
 253
 254         if (!machine_has_topology) {
 255                 topology_update_polarization_simple();
 256                 return 0;
 257         }
 258         init_timer_deferrable(&topology_timer);
 259         if (machine_has_topology_irq) {
 260                 rc = register_external_interrupt(0x2005, topology_interrupt);
 261                 if (rc)
 262                         return rc;
 263                 ctl_set_bit(0, 8);
 264         }
 265         else
 266                 set_topology_timer();
 267         return 0;
 268 }
 269 __initcall(init_topology_update);
 270
 271 void __init s390_init_cpu_topology(void)
 272 {
 273         unsigned long long facility_bits;
 274         struct tl_info *info;
 275         struct core_info *core;
 276         int nr_cores;
 277         int i;
 278
 279         if (stfle(&facility_bits, 1) <= 0)
 280                 return;
 281         if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
 282                 return;
 283         machine_has_topology = 1;
 284
 285         if (facility_bits & (1ULL << 51))
 286                 machine_has_topology_irq = 1;
 287
 288         tl_info = alloc_bootmem_pages(PAGE_SIZE);
 289         if (!tl_info)
 290                 goto error;
 291         info = tl_info;
 292         stsi(info, 15, 1, 2);
 293
 294         nr_cores = info->mag[NR_MAG - 2];
 295         for (i = 0; i < info->mnest - 2; i++)
 296                 nr_cores *= info->mag[NR_MAG - 3 - i];
 297
 298         printk(KERN_INFO "CPU topology:");
 299         for (i = 0; i < NR_MAG; i++)
 300                 printk(" %d", info->mag[i]);
 301         printk(" / %d\n", info->mnest);
 302
 303         core = &core_info;
 304         for (i = 0; i < nr_cores; i++) {
 305                 core->next = alloc_bootmem(sizeof(struct core_info));
 306                 core = core->next;
 307                 if (!core)
 308                         goto error;
 309         }
 310         return;
 311 error:
 312         machine_has_topology = 0;
 313         machine_has_topology_irq = 0;
 314 }