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
  22 #define PTF_HORIZONTAL  (0UL)
  23 #define PTF_VERTICAL    (1UL)
  24 #define PTF_CHECK       (2UL)
  25
  26 struct mask_info {
  27         struct mask_info *next;
  28         unsigned char id;
  29         cpumask_t mask;
  30 };
  31
  32 static int topology_enabled = 1;
  33 static void topology_work_fn(struct work_struct *work);
  34 static struct sysinfo_15_1_x *tl_info;
  35 static struct timer_list topology_timer;
  36 static void set_topology_timer(void);
  37 static DECLARE_WORK(topology_work, topology_work_fn);
  38 /* topology_lock protects the core linked list */
  39 static DEFINE_SPINLOCK(topology_lock);
  40
  41 static struct mask_info core_info;
  42 cpumask_t cpu_core_map[NR_CPUS];
  43 unsigned char cpu_core_id[NR_CPUS];
  44
  45 #ifdef CONFIG_SCHED_BOOK
  46 static struct mask_info book_info;
  47 cpumask_t cpu_book_map[NR_CPUS];
  48 unsigned char cpu_book_id[NR_CPUS];
  49 #endif
  50
  51 static cpumask_t cpu_group_map(struct mask_info *info, unsigned int cpu)
  52 {
  53         cpumask_t mask;
  54
  55         cpus_clear(mask);
  56         if (!topology_enabled || !MACHINE_HAS_TOPOLOGY)
  57                 return cpu_possible_map;
  58         while (info) {
  59                 if (cpu_isset(cpu, info->mask)) {
  60                         mask = info->mask;
  61                         break;
  62                 }
  63                 info = info->next;
  64         }
  65         if (cpus_empty(mask))
  66                 mask = cpumask_of_cpu(cpu);
  67         return mask;
  68 }
  69
  70 static void add_cpus_to_mask(struct topology_cpu *tl_cpu,
  71                              struct mask_info *book, struct mask_info *core)
  72 {
  73         unsigned int cpu;
  74
  75         for (cpu = find_first_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS);
  76              cpu < TOPOLOGY_CPU_BITS;
  77              cpu = find_next_bit(&tl_cpu->mask[0], TOPOLOGY_CPU_BITS, cpu + 1))
  78         {
  79                 unsigned int rcpu, lcpu;
  80
  81                 rcpu = TOPOLOGY_CPU_BITS - 1 - cpu + tl_cpu->origin;
  82                 for_each_present_cpu(lcpu) {
  83                         if (cpu_logical_map(lcpu) != rcpu)
  84                                 continue;
  85 #ifdef CONFIG_SCHED_BOOK
  86                         cpu_set(lcpu, book->mask);
  87                         cpu_book_id[lcpu] = book->id;
  88 #endif
  89                         cpu_set(lcpu, core->mask);
  90                         cpu_core_id[lcpu] = core->id;
  91                         smp_cpu_polarization[lcpu] = tl_cpu->pp;
  92                 }
  93         }
  94 }
  95
  96 static void clear_masks(void)
  97 {
  98         struct mask_info *info;
  99
 100         info = &core_info;
 101         while (info) {
 102                 cpus_clear(info->mask);
 103                 info = info->next;
 104         }
 105 #ifdef CONFIG_SCHED_BOOK
 106         info = &book_info;
 107         while (info) {
 108                 cpus_clear(info->mask);
 109                 info = info->next;
 110         }
 111 #endif
 112 }
 113
 114 static union topology_entry *next_tle(union topology_entry *tle)
 115 {
 116         if (!tle->nl)
 117                 return (union topology_entry *)((struct topology_cpu *)tle + 1);
 118         return (union topology_entry *)((struct topology_container *)tle + 1);
 119 }
 120
 121 static void tl_to_cores(struct sysinfo_15_1_x *info)
 122 {
 123 #ifdef CONFIG_SCHED_BOOK
 124         struct mask_info *book = &book_info;
 125 #else
 126         struct mask_info *book = NULL;
 127 #endif
 128         struct mask_info *core = &core_info;
 129         union topology_entry *tle, *end;
 130
 131
 132         spin_lock_irq(&topology_lock);
 133         clear_masks();
 134         tle = info->tle;
 135         end = (union topology_entry *)((unsigned long)info + info->length);
 136         while (tle < end) {
 137                 switch (tle->nl) {
 138 #ifdef CONFIG_SCHED_BOOK
 139                 case 2:
 140                         book = book->next;
 141                         book->id = tle->container.id;
 142                         break;
 143 #endif
 144                 case 1:
 145                         core = core->next;
 146                         core->id = tle->container.id;
 147                         break;
 148                 case 0:
 149                         add_cpus_to_mask(&tle->cpu, book, core);
 150                         break;
 151                 default:
 152                         clear_masks();
 153                         goto out;
 154                 }
 155                 tle = next_tle(tle);
 156         }
 157 out:
 158         spin_unlock_irq(&topology_lock);
 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_possible_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_possible_cpu(cpu)
 198                 smp_cpu_polarization[cpu] = POLARIZATION_UNKNWN;
 199         return rc;
 200 }
 201
 202 static void update_cpu_core_map(void)
 203 {
 204         unsigned long flags;
 205         int cpu;
 206
 207         spin_lock_irqsave(&topology_lock, flags);
 208         for_each_possible_cpu(cpu) {
 209                 cpu_core_map[cpu] = cpu_group_map(&core_info, cpu);
 210 #ifdef CONFIG_SCHED_BOOK
 211                 cpu_book_map[cpu] = cpu_group_map(&book_info, cpu);
 212 #endif
 213         }
 214         spin_unlock_irqrestore(&topology_lock, flags);
 215 }
 216
 217 void store_topology(struct sysinfo_15_1_x *info)
 218 {
 219 #ifdef CONFIG_SCHED_BOOK
 220         int rc;
 221
 222         rc = stsi(info, 15, 1, 3);
 223         if (rc != -ENOSYS)
 224                 return;
 225 #endif
 226         stsi(info, 15, 1, 2);
 227 }
 228
 229 int arch_update_cpu_topology(void)
 230 {
 231         struct sysinfo_15_1_x *info = tl_info;
 232         struct sys_device *sysdev;
 233         int cpu;
 234
 235         if (!MACHINE_HAS_TOPOLOGY) {
 236                 update_cpu_core_map();
 237                 topology_update_polarization_simple();
 238                 return 0;
 239         }
 240         store_topology(info);
 241         tl_to_cores(info);
 242         update_cpu_core_map();
 243         for_each_online_cpu(cpu) {
 244                 sysdev = get_cpu_sysdev(cpu);
 245                 kobject_uevent(&sysdev->kobj, KOBJ_CHANGE);
 246         }
 247         return 1;
 248 }
 249
 250 static void topology_work_fn(struct work_struct *work)
 251 {
 252         rebuild_sched_domains();
 253 }
 254
 255 void topology_schedule_update(void)
 256 {
 257         schedule_work(&topology_work);
 258 }
 259
 260 static void topology_timer_fn(unsigned long ignored)
 261 {
 262         if (ptf(PTF_CHECK))
 263                 topology_schedule_update();
 264         set_topology_timer();
 265 }
 266
 267 static void set_topology_timer(void)
 268 {
 269         topology_timer.function = topology_timer_fn;
 270         topology_timer.data = 0;
 271         topology_timer.expires = jiffies + 60 * HZ;
 272         add_timer(&topology_timer);
 273 }
 274
 275 static int __init early_parse_topology(char *p)
 276 {
 277         if (strncmp(p, "off", 3))
 278                 return 0;
 279         topology_enabled = 0;
 280         return 0;
 281 }
 282 early_param("topology", early_parse_topology);
 283
 284 static int __init init_topology_update(void)
 285 {
 286         int rc;
 287
 288         rc = 0;
 289         if (!MACHINE_HAS_TOPOLOGY) {
 290                 topology_update_polarization_simple();
 291                 goto out;
 292         }
 293         init_timer_deferrable(&topology_timer);
 294         set_topology_timer();
 295 out:
 296         update_cpu_core_map();
 297         return rc;
 298 }
 299 __initcall(init_topology_update);
 300
 301 static void alloc_masks(struct sysinfo_15_1_x *info, struct mask_info *mask,
 302                         int offset)
 303 {
 304         int i, nr_masks;
 305
 306         nr_masks = info->mag[TOPOLOGY_NR_MAG - offset];
 307         for (i = 0; i < info->mnest - offset; i++)
 308                 nr_masks *= info->mag[TOPOLOGY_NR_MAG - offset - 1 - i];
 309         nr_masks = max(nr_masks, 1);
 310         for (i = 0; i < nr_masks; i++) {
 311                 mask->next = alloc_bootmem(sizeof(struct mask_info));
 312                 mask = mask->next;
 313         }
 314 }
 315
 316 void __init s390_init_cpu_topology(void)
 317 {
 318         struct sysinfo_15_1_x *info;
 319         int i;
 320
 321         if (!MACHINE_HAS_TOPOLOGY)
 322                 return;
 323         tl_info = alloc_bootmem_pages(PAGE_SIZE);
 324         info = tl_info;
 325         store_topology(info);
 326         pr_info("The CPU configuration topology of the machine is:");
 327         for (i = 0; i < TOPOLOGY_NR_MAG; i++)
 328                 printk(" %d", info->mag[i]);
 329         printk(" / %d\n", info->mnest);
 330         alloc_masks(info, &core_info, 2);
 331 #ifdef CONFIG_SCHED_BOOK
 332         alloc_masks(info, &book_info, 3);
 333 #endif
 334 }