arch/blackfin/mach-common/smp.c

   1 /*
   2  * IPI management based on arch/arm/kernel/smp.c (Copyright 2002 ARM Limited)
   3  *
   4  * Copyright 2007-2009 Analog Devices Inc.
   5  *                         Philippe Gerum <rpm@xenomai.org>
   6  *
   7  * Licensed under the GPL-2.
   8  */
   9
  10 #include <linux/module.h>
  11 #include <linux/delay.h>
  12 #include <linux/init.h>
  13 #include <linux/spinlock.h>
  14 #include <linux/sched.h>
  15 #include <linux/interrupt.h>
  16 #include <linux/cache.h>
  17 #include <linux/profile.h>
  18 #include <linux/errno.h>
  19 #include <linux/mm.h>
  20 #include <linux/cpu.h>
  21 #include <linux/smp.h>
  22 #include <linux/seq_file.h>
  23 #include <linux/irq.h>
  24 #include <asm/atomic.h>
  25 #include <asm/cacheflush.h>
  26 #include <asm/mmu_context.h>
  27 #include <asm/pgtable.h>
  28 #include <asm/pgalloc.h>
  29 #include <asm/processor.h>
  30 #include <asm/ptrace.h>
  31 #include <asm/cpu.h>
  32 #include <asm/time.h>
  33 #include <linux/err.h>
  34
  35 /*
  36  * Anomaly notes:
  37  * 05000120 - we always define corelock as 32-bit integer in L2
  38  */
  39 struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));
  40
  41 void __cpuinitdata *init_retx_coreb, *init_saved_retx_coreb,
  42         *init_saved_seqstat_coreb, *init_saved_icplb_fault_addr_coreb,
  43         *init_saved_dcplb_fault_addr_coreb;
  44
  45 cpumask_t cpu_possible_map;
  46 EXPORT_SYMBOL(cpu_possible_map);
  47
  48 cpumask_t cpu_online_map;
  49 EXPORT_SYMBOL(cpu_online_map);
  50
  51 #define BFIN_IPI_RESCHEDULE   0
  52 #define BFIN_IPI_CALL_FUNC    1
  53 #define BFIN_IPI_CPU_STOP     2
  54
  55 struct blackfin_flush_data {
  56         unsigned long start;
  57         unsigned long end;
  58 };
  59
  60 void *secondary_stack;
  61
  62
  63 struct smp_call_struct {
  64         void (*func)(void *info);
  65         void *info;
  66         int wait;
  67         cpumask_t pending;
  68         cpumask_t waitmask;
  69 };
  70
  71 static struct blackfin_flush_data smp_flush_data;
  72
  73 static DEFINE_SPINLOCK(stop_lock);
  74
  75 struct ipi_message {
  76         struct list_head list;
  77         unsigned long type;
  78         struct smp_call_struct call_struct;
  79 };
  80
  81 struct ipi_message_queue {
  82         struct list_head head;
  83         spinlock_t lock;
  84         unsigned long count;
  85 };
  86
  87 static DEFINE_PER_CPU(struct ipi_message_queue, ipi_msg_queue);
  88
  89 static void ipi_cpu_stop(unsigned int cpu)
  90 {
  91         spin_lock(&stop_lock);
  92         printk(KERN_CRIT "CPU%u: stopping\n", cpu);
  93         dump_stack();
  94         spin_unlock(&stop_lock);
  95
  96         cpu_clear(cpu, cpu_online_map);
  97
  98         local_irq_disable();
  99
 100         while (1)
 101                 SSYNC();
 102 }
 103
 104 static void ipi_flush_icache(void *info)
 105 {
 106         struct blackfin_flush_data *fdata = info;
 107
 108         /* Invalidate the memory holding the bounds of the flushed region. */
 109         blackfin_dcache_invalidate_range((unsigned long)fdata,
 110                                          (unsigned long)fdata + sizeof(*fdata));
 111
 112         blackfin_icache_flush_range(fdata->start, fdata->end);
 113 }
 114
 115 static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
 116 {
 117         int wait;
 118         void (*func)(void *info);
 119         void *info;
 120         func = msg->call_struct.func;
 121         info = msg->call_struct.info;
 122         wait = msg->call_struct.wait;
 123         cpu_clear(cpu, msg->call_struct.pending);
 124         func(info);
 125         if (wait)
 126                 cpu_clear(cpu, msg->call_struct.waitmask);
 127         else
 128                 kfree(msg);
 129 }
 130
 131 static irqreturn_t ipi_handler(int irq, void *dev_instance)
 132 {
 133         struct ipi_message *msg;
 134         struct ipi_message_queue *msg_queue;
 135         unsigned int cpu = smp_processor_id();
 136
 137         platform_clear_ipi(cpu);
 138
 139         msg_queue = &__get_cpu_var(ipi_msg_queue);
 140         msg_queue->count++;
 141
 142         spin_lock(&msg_queue->lock);
 143         while (!list_empty(&msg_queue->head)) {
 144                 msg = list_entry(msg_queue->head.next, typeof(*msg), list);
 145                 list_del(&msg->list);
 146                 switch (msg->type) {
 147                 case BFIN_IPI_RESCHEDULE:
 148                         /* That's the easiest one; leave it to
 149                          * return_from_int. */
 150                         kfree(msg);
 151                         break;
 152                 case BFIN_IPI_CALL_FUNC:
 153                         spin_unlock(&msg_queue->lock);
 154                         ipi_call_function(cpu, msg);
 155                         spin_lock(&msg_queue->lock);
 156                         break;
 157                 case BFIN_IPI_CPU_STOP:
 158                         spin_unlock(&msg_queue->lock);
 159                         ipi_cpu_stop(cpu);
 160                         spin_lock(&msg_queue->lock);
 161                         kfree(msg);
 162                         break;
 163                 default:
 164                         printk(KERN_CRIT "CPU%u: Unknown IPI message \
 165                         0x%lx\n", cpu, msg->type);
 166                         kfree(msg);
 167                         break;
 168                 }
 169         }
 170         spin_unlock(&msg_queue->lock);
 171         return IRQ_HANDLED;
 172 }
 173
 174 static void ipi_queue_init(void)
 175 {
 176         unsigned int cpu;
 177         struct ipi_message_queue *msg_queue;
 178         for_each_possible_cpu(cpu) {
 179                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
 180                 INIT_LIST_HEAD(&msg_queue->head);
 181                 spin_lock_init(&msg_queue->lock);
 182                 msg_queue->count = 0;
 183         }
 184 }
 185
 186 int smp_call_function(void (*func)(void *info), void *info, int wait)
 187 {
 188         unsigned int cpu;
 189         cpumask_t callmap;
 190         unsigned long flags;
 191         struct ipi_message_queue *msg_queue;
 192         struct ipi_message *msg;
 193
 194         callmap = cpu_online_map;
 195         cpu_clear(smp_processor_id(), callmap);
 196         if (cpus_empty(callmap))
 197                 return 0;
 198
 199         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 200         if (!msg)
 201                 return -ENOMEM;
 202         INIT_LIST_HEAD(&msg->list);
 203         msg->call_struct.func = func;
 204         msg->call_struct.info = info;
 205         msg->call_struct.wait = wait;
 206         msg->call_struct.pending = callmap;
 207         msg->call_struct.waitmask = callmap;
 208         msg->type = BFIN_IPI_CALL_FUNC;
 209
 210         for_each_cpu_mask(cpu, callmap) {
 211                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
 212                 spin_lock_irqsave(&msg_queue->lock, flags);
 213                 list_add_tail(&msg->list, &msg_queue->head);
 214                 spin_unlock_irqrestore(&msg_queue->lock, flags);
 215                 platform_send_ipi_cpu(cpu);
 216         }
 217         if (wait) {
 218                 while (!cpus_empty(msg->call_struct.waitmask))
 219                         blackfin_dcache_invalidate_range(
 220                                 (unsigned long)(&msg->call_struct.waitmask),
 221                                 (unsigned long)(&msg->call_struct.waitmask));
 222                 kfree(msg);
 223         }
 224         return 0;
 225 }
 226 EXPORT_SYMBOL_GPL(smp_call_function);
 227
 228 int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
 229                                 int wait)
 230 {
 231         unsigned int cpu = cpuid;
 232         cpumask_t callmap;
 233         unsigned long flags;
 234         struct ipi_message_queue *msg_queue;
 235         struct ipi_message *msg;
 236
 237         if (cpu_is_offline(cpu))
 238                 return 0;
 239         cpus_clear(callmap);
 240         cpu_set(cpu, callmap);
 241
 242         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 243         if (!msg)
 244                 return -ENOMEM;
 245         INIT_LIST_HEAD(&msg->list);
 246         msg->call_struct.func = func;
 247         msg->call_struct.info = info;
 248         msg->call_struct.wait = wait;
 249         msg->call_struct.pending = callmap;
 250         msg->call_struct.waitmask = callmap;
 251         msg->type = BFIN_IPI_CALL_FUNC;
 252
 253         msg_queue = &per_cpu(ipi_msg_queue, cpu);
 254         spin_lock_irqsave(&msg_queue->lock, flags);
 255         list_add_tail(&msg->list, &msg_queue->head);
 256         spin_unlock_irqrestore(&msg_queue->lock, flags);
 257         platform_send_ipi_cpu(cpu);
 258
 259         if (wait) {
 260                 while (!cpus_empty(msg->call_struct.waitmask))
 261                         blackfin_dcache_invalidate_range(
 262                                 (unsigned long)(&msg->call_struct.waitmask),
 263                                 (unsigned long)(&msg->call_struct.waitmask));
 264                 kfree(msg);
 265         }
 266         return 0;
 267 }
 268 EXPORT_SYMBOL_GPL(smp_call_function_single);
 269
 270 void smp_send_reschedule(int cpu)
 271 {
 272         unsigned long flags;
 273         struct ipi_message_queue *msg_queue;
 274         struct ipi_message *msg;
 275
 276         if (cpu_is_offline(cpu))
 277                 return;
 278
 279         msg = kzalloc(sizeof(*msg), GFP_ATOMIC);
 280         if (!msg)
 281                 return;
 282         INIT_LIST_HEAD(&msg->list);
 283         msg->type = BFIN_IPI_RESCHEDULE;
 284
 285         msg_queue = &per_cpu(ipi_msg_queue, cpu);
 286         spin_lock_irqsave(&msg_queue->lock, flags);
 287         list_add_tail(&msg->list, &msg_queue->head);
 288         spin_unlock_irqrestore(&msg_queue->lock, flags);
 289         platform_send_ipi_cpu(cpu);
 290
 291         return;
 292 }
 293
 294 void smp_send_stop(void)
 295 {
 296         unsigned int cpu;
 297         cpumask_t callmap;
 298         unsigned long flags;
 299         struct ipi_message_queue *msg_queue;
 300         struct ipi_message *msg;
 301
 302         callmap = cpu_online_map;
 303         cpu_clear(smp_processor_id(), callmap);
 304         if (cpus_empty(callmap))
 305                 return;
 306
 307         msg = kzalloc(sizeof(*msg), GFP_ATOMIC);
 308         if (!msg)
 309                 return;
 310         INIT_LIST_HEAD(&msg->list);
 311         msg->type = BFIN_IPI_CPU_STOP;
 312
 313         for_each_cpu_mask(cpu, callmap) {
 314                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
 315                 spin_lock_irqsave(&msg_queue->lock, flags);
 316                 list_add_tail(&msg->list, &msg_queue->head);
 317                 spin_unlock_irqrestore(&msg_queue->lock, flags);
 318                 platform_send_ipi_cpu(cpu);
 319         }
 320         return;
 321 }
 322
 323 int __cpuinit __cpu_up(unsigned int cpu)
 324 {
 325         struct task_struct *idle;
 326         int ret;
 327
 328         idle = fork_idle(cpu);
 329         if (IS_ERR(idle)) {
 330                 printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
 331                 return PTR_ERR(idle);
 332         }
 333
 334         secondary_stack = task_stack_page(idle) + THREAD_SIZE;
 335         smp_wmb();
 336
 337         ret = platform_boot_secondary(cpu, idle);
 338
 339         if (ret) {
 340                 cpu_clear(cpu, cpu_present_map);
 341                 printk(KERN_CRIT "CPU%u: processor failed to boot (%d)\n", cpu, ret);
 342                 free_task(idle);
 343         } else
 344                 cpu_set(cpu, cpu_online_map);
 345
 346         secondary_stack = NULL;
 347
 348         return ret;
 349 }
 350
 351 static void __cpuinit setup_secondary(unsigned int cpu)
 352 {
 353 #if !defined(CONFIG_TICKSOURCE_GPTMR0)
 354         struct irq_desc *timer_desc;
 355 #endif
 356         unsigned long ilat;
 357
 358         bfin_write_IMASK(0);
 359         CSYNC();
 360         ilat = bfin_read_ILAT();
 361         CSYNC();
 362         bfin_write_ILAT(ilat);
 363         CSYNC();
 364
 365         /* Enable interrupt levels IVG7-15. IARs have been already
 366          * programmed by the boot CPU.  */
 367         bfin_irq_flags |= IMASK_IVG15 |
 368             IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 |
 369             IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW;
 370
 371 #if defined(CONFIG_TICKSOURCE_GPTMR0)
 372         /* Power down the core timer, just to play safe. */
 373         bfin_write_TCNTL(0);
 374
 375         /* system timer0 has been setup by CoreA. */
 376 #else
 377         timer_desc = irq_desc + IRQ_CORETMR;
 378         setup_core_timer();
 379         timer_desc->chip->enable(IRQ_CORETMR);
 380 #endif
 381 }
 382
 383 void __cpuinit secondary_start_kernel(void)
 384 {
 385         unsigned int cpu = smp_processor_id();
 386         struct mm_struct *mm = &init_mm;
 387
 388         if (_bfin_swrst & SWRST_DBL_FAULT_B) {
 389                 printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
 390 #ifdef CONFIG_DEBUG_DOUBLEFAULT
 391                 printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
 392                         (int)init_saved_seqstat_coreb & SEQSTAT_EXCAUSE, init_saved_retx_coreb);
 393                 printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr_coreb);
 394                 printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr_coreb);
 395 #endif
 396                 printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
 397                         init_retx_coreb);
 398         }
 399
 400         /*
 401          * We want the D-cache to be enabled early, in case the atomic
 402          * support code emulates cache coherence (see
 403          * __ARCH_SYNC_CORE_DCACHE).
 404          */
 405         init_exception_vectors();
 406
 407         bfin_setup_caches(cpu);
 408
 409         local_irq_disable();
 410
 411         /* Attach the new idle task to the global mm. */
 412         atomic_inc(&mm->mm_users);
 413         atomic_inc(&mm->mm_count);
 414         current->active_mm = mm;
 415         BUG_ON(current->mm);    /* Can't be, but better be safe than sorry. */
 416
 417         preempt_disable();
 418
 419         setup_secondary(cpu);
 420
 421         local_irq_enable();
 422
 423         platform_secondary_init(cpu);
 424
 425         cpu_idle();
 426 }
 427
 428 void __init smp_prepare_boot_cpu(void)
 429 {
 430 }
 431
 432 void __init smp_prepare_cpus(unsigned int max_cpus)
 433 {
 434         platform_prepare_cpus(max_cpus);
 435         ipi_queue_init();
 436         platform_request_ipi(&ipi_handler);
 437 }
 438
 439 void __init smp_cpus_done(unsigned int max_cpus)
 440 {
 441         unsigned long bogosum = 0;
 442         unsigned int cpu;
 443
 444         for_each_online_cpu(cpu)
 445                 bogosum += loops_per_jiffy;
 446
 447         printk(KERN_INFO "SMP: Total of %d processors activated "
 448                "(%lu.%02lu BogoMIPS).\n",
 449                num_online_cpus(),
 450                bogosum / (500000/HZ),
 451                (bogosum / (5000/HZ)) % 100);
 452 }
 453
 454 void smp_icache_flush_range_others(unsigned long start, unsigned long end)
 455 {
 456         smp_flush_data.start = start;
 457         smp_flush_data.end = end;
 458
 459         if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 0))
 460                 printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
 461 }
 462 EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);
 463
 464 #ifdef __ARCH_SYNC_CORE_ICACHE
 465 void resync_core_icache(void)
 466 {
 467         unsigned int cpu = get_cpu();
 468         blackfin_invalidate_entire_icache();
 469         ++per_cpu(cpu_data, cpu).icache_invld_count;
 470         put_cpu();
 471 }
 472 EXPORT_SYMBOL(resync_core_icache);
 473 #endif
 474
 475 #ifdef __ARCH_SYNC_CORE_DCACHE
 476 unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));
 477
 478 void resync_core_dcache(void)
 479 {
 480         unsigned int cpu = get_cpu();
 481         blackfin_invalidate_entire_dcache();
 482         ++per_cpu(cpu_data, cpu).dcache_invld_count;
 483         put_cpu();
 484 }
 485 EXPORT_SYMBOL(resync_core_dcache);
 486 #endif