arch/s390/kernel/topology.c

   1 /*
   2  *  arch/s390/kernel/topology.c
   3  *
   4  *    Copyright IBM Corp. 2007
   5  *    Author(s): Heiko Carstens <heiko.carstens@de.ibm.com>
   6  */
   7
   8 #include <linux/kernel.h>
   9 #include <linux/mm.h>
  10 #include <linux/init.h>
  11 #include <linux/device.h>
  12 #include <linux/bootmem.h>
  13 #include <linux/sched.h>
  14 #include <linux/workqueue.h>
  15 #include <linux/cpu.h>
  16 #include <linux/smp.h>
  17 #include <asm/delay.h>
  18 #include <asm/s390_ext.h>
  19 #include <asm/sysinfo.h>
  20
  21 #define CPU_BITS 64
  22
  23 struct tl_cpu {
  24         unsigned char reserved[6];
  25         unsigned short origin;
  26         unsigned long mask[CPU_BITS / BITS_PER_LONG];
  27 };
  28
  29 struct tl_container {
  30         unsigned char reserved[8];
  31 };
  32
  33 union tl_entry {
  34         unsigned char nl;
  35         struct tl_cpu cpu;
  36         struct tl_container container;
  37 };
  38
  39 #define NR_MAG 6
  40
  41 struct tl_info {
  42         unsigned char reserved0[2];
  43         unsigned short length;
  44         unsigned char mag[NR_MAG];
  45         unsigned char reserved1;
  46         unsigned char mnest;
  47         unsigned char reserved2[4];
  48         union tl_entry tle[0];
  49 };
  50
  51 struct core_info {
  52         struct core_info *next;
  53         cpumask_t mask;
  54 };
  55
  56 static void topology_work_fn(struct work_struct *work);
  57 static struct tl_info *tl_info;
  58 static struct core_info core_info;
  59 static int machine_has_topology;
  60 static int machine_has_topology_irq;
  61 static struct timer_list topology_timer;
  62 static void set_topology_timer(void);
  63 static DECLARE_WORK(topology_work, topology_work_fn);
  64
  65 cpumask_t cpu_coregroup_map(unsigned int cpu)
  66 {
  67         struct core_info *core = &core_info;
  68         cpumask_t mask;
  69
  70         cpus_clear(mask);
  71         if (!machine_has_topology)
  72                 return cpu_present_map;
  73         mutex_lock(&smp_cpu_state_mutex);
  74         while (core) {
  75                 if (cpu_isset(cpu, core->mask)) {
  76                         mask = core->mask;
  77                         break;
  78                 }
  79                 core = core->next;
  80         }
  81         mutex_unlock(&smp_cpu_state_mutex);
  82         if (cpus_empty(mask))
  83                 mask = cpumask_of_cpu(cpu);
  84         return mask;
  85 }
  86
  87 static void add_cpus_to_core(struct tl_cpu *tl_cpu, struct core_info *core)
  88 {
  89         unsigned int cpu;
  90
  91         for (cpu = find_first_bit(&tl_cpu->mask[0], CPU_BITS);
  92              cpu < CPU_BITS;
  93              cpu = find_next_bit(&tl_cpu->mask[0], CPU_BITS, cpu + 1))
  94         {
  95                 unsigned int rcpu, lcpu;
  96
  97                 rcpu = CPU_BITS - 1 - cpu + tl_cpu->origin;
  98                 for_each_present_cpu(lcpu) {
  99                         if (__cpu_logical_map[lcpu] == rcpu)
 100                                 cpu_set(lcpu, core->mask);
 101                 }
 102         }
 103 }
 104
 105 static void clear_cores(void)
 106 {
 107         struct core_info *core = &core_info;
 108
 109         while (core) {
 110                 cpus_clear(core->mask);
 111                 core = core->next;
 112         }
 113 }
 114
 115 static union tl_entry *next_tle(union tl_entry *tle)
 116 {
 117         if (tle->nl)
 118                 return (union tl_entry *)((struct tl_container *)tle + 1);
 119         else
 120                 return (union tl_entry *)((struct tl_cpu *)tle + 1);
 121 }
 122
 123 static void tl_to_cores(struct tl_info *info)
 124 {
 125         union tl_entry *tle, *end;
 126         struct core_info *core = &core_info;
 127
 128         mutex_lock(&smp_cpu_state_mutex);
 129         clear_cores();
 130         tle = (union tl_entry *)&info->tle;
 131         end = (union tl_entry *)((unsigned long)info + info->length);
 132         while (tle < end) {
 133                 switch (tle->nl) {
 134                 case 5:
 135                 case 4:
 136                 case 3:
 137                 case 2:
 138                         break;
 139                 case 1:
 140                         core = core->next;
 141                         break;
 142                 case 0:
 143                         add_cpus_to_core(&tle->cpu, core);
 144                         break;
 145                 default:
 146                         clear_cores();
 147                         machine_has_topology = 0;
 148                         return;
 149                 }
 150                 tle = next_tle(tle);
 151         }
 152         mutex_unlock(&smp_cpu_state_mutex);
 153 }
 154
 155 static int ptf(void)
 156 {
 157         int rc;
 158
 159         asm volatile(
 160                 "       .insn   rre,0xb9a20000,%1,%1\n"
 161                 "       ipm     %0\n"
 162                 "       srl     %0,28\n"
 163                 : "=d" (rc)
 164                 : "d" (2UL)  : "cc");
 165         return rc;
 166 }
 167
 168 void arch_update_cpu_topology(void)
 169 {
 170         struct tl_info *info = tl_info;
 171         struct sys_device *sysdev;
 172         int cpu;
 173
 174         if (!machine_has_topology)
 175                 return;
 176         ptf();
 177         stsi(info, 15, 1, 2);
 178         tl_to_cores(info);
 179         for_each_online_cpu(cpu) {
 180                 sysdev = get_cpu_sysdev(cpu);
 181                 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
 182         }
 183 }
 184
 185 static void topology_work_fn(struct work_struct *work)
 186 {
 187         arch_reinit_sched_domains();
 188 }
 189
 190 static void topology_timer_fn(unsigned long ignored)
 191 {
 192         if (ptf())
 193                 schedule_work(&topology_work);
 194         set_topology_timer();
 195 }
 196
 197 static void set_topology_timer(void)
 198 {
 199         topology_timer.function = topology_timer_fn;
 200         topology_timer.data = 0;
 201         topology_timer.expires = jiffies + 60 * HZ;
 202         add_timer(&topology_timer);
 203 }
 204
 205 static void topology_interrupt(__u16 code)
 206 {
 207         schedule_work(&topology_work);
 208 }
 209
 210 static int __init init_topology_update(void)
 211 {
 212         int rc;
 213
 214         if (!machine_has_topology)
 215                 return 0;
 216         init_timer(&topology_timer);
 217         if (machine_has_topology_irq) {
 218                 rc = register_external_interrupt(0x2005, topology_interrupt);
 219                 if (rc)
 220                         return rc;
 221                 ctl_set_bit(0, 8);
 222         }
 223         else
 224                 set_topology_timer();
 225         return 0;
 226 }
 227 __initcall(init_topology_update);
 228
 229 void __init s390_init_cpu_topology(void)
 230 {
 231         unsigned long long facility_bits;
 232         struct tl_info *info;
 233         struct core_info *core;
 234         int nr_cores;
 235         int i;
 236
 237         if (stfle(&facility_bits, 1) <= 0)
 238                 return;
 239         if (!(facility_bits & (1ULL << 52)) || !(facility_bits & (1ULL << 61)))
 240                 return;
 241         machine_has_topology = 1;
 242
 243         if (facility_bits & (1ULL << 51))
 244                 machine_has_topology_irq = 1;
 245
 246         tl_info = alloc_bootmem_pages(PAGE_SIZE);
 247         if (!tl_info)
 248                 goto error;
 249         info = tl_info;
 250         stsi(info, 15, 1, 2);
 251
 252         nr_cores = info->mag[NR_MAG - 2];
 253         for (i = 0; i < info->mnest - 2; i++)
 254                 nr_cores *= info->mag[NR_MAG - 3 - i];
 255
 256         printk(KERN_INFO "CPU topology:");
 257         for (i = 0; i < NR_MAG; i++)
 258                 printk(" %d", info->mag[i]);
 259         printk(" / %d\n", info->mnest);
 260
 261         core = &core_info;
 262         for (i = 0; i < nr_cores; i++) {
 263                 core->next = alloc_bootmem(sizeof(struct core_info));
 264                 core = core->next;
 265                 if (!core)
 266                         goto error;
 267         }
 268         return;
 269 error:
 270         machine_has_topology = 0;
 271         machine_has_topology_irq = 0;
 272 }