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   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 #ifdef __ARCH_SYNC_CORE_DCACHE
 127                 /*
 128                  * 'wait' usually means synchronization between CPUs.
 129                  * Invalidate D cache in case shared data was changed
 130                  * by func() to ensure cache coherence.
 131                  */
 132                 resync_core_dcache();
 133 #endif
 134                 cpu_clear(cpu, msg->call_struct.waitmask);
 135         } else
 136                 kfree(msg);
 137 }
 138
 139 static irqreturn_t ipi_handler(int irq, void *dev_instance)
 140 {
 141         struct ipi_message *msg;
 142         struct ipi_message_queue *msg_queue;
 143         unsigned int cpu = smp_processor_id();
 144
 145         platform_clear_ipi(cpu);
 146
 147         msg_queue = &__get_cpu_var(ipi_msg_queue);
 148         msg_queue->count++;
 149
 150         spin_lock(&msg_queue->lock);
 151         while (!list_empty(&msg_queue->head)) {
 152                 msg = list_entry(msg_queue->head.next, typeof(*msg), list);
 153                 list_del(&msg->list);
 154                 switch (msg->type) {
 155                 case BFIN_IPI_RESCHEDULE:
 156                         /* That's the easiest one; leave it to
 157                          * return_from_int. */
 158                         kfree(msg);
 159                         break;
 160                 case BFIN_IPI_CALL_FUNC:
 161                         spin_unlock(&msg_queue->lock);
 162                         ipi_call_function(cpu, msg);
 163                         spin_lock(&msg_queue->lock);
 164                         break;
 165                 case BFIN_IPI_CPU_STOP:
 166                         spin_unlock(&msg_queue->lock);
 167                         ipi_cpu_stop(cpu);
 168                         spin_lock(&msg_queue->lock);
 169                         kfree(msg);
 170                         break;
 171                 default:
 172                         printk(KERN_CRIT "CPU%u: Unknown IPI message \
 173                         0x%lx\n", cpu, msg->type);
 174                         kfree(msg);
 175                         break;
 176                 }
 177         }
 178         spin_unlock(&msg_queue->lock);
 179         return IRQ_HANDLED;
 180 }
 181
 182 static void ipi_queue_init(void)
 183 {
 184         unsigned int cpu;
 185         struct ipi_message_queue *msg_queue;
 186         for_each_possible_cpu(cpu) {
 187                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
 188                 INIT_LIST_HEAD(&msg_queue->head);
 189                 spin_lock_init(&msg_queue->lock);
 190                 msg_queue->count = 0;
 191         }
 192 }
 193
 194 int smp_call_function(void (*func)(void *info), void *info, int wait)
 195 {
 196         unsigned int cpu;
 197         cpumask_t callmap;
 198         unsigned long flags;
 199         struct ipi_message_queue *msg_queue;
 200         struct ipi_message *msg;
 201
 202         callmap = cpu_online_map;
 203         cpu_clear(smp_processor_id(), callmap);
 204         if (cpus_empty(callmap))
 205                 return 0;
 206
 207         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 208         if (!msg)
 209                 return -ENOMEM;
 210         INIT_LIST_HEAD(&msg->list);
 211         msg->call_struct.func = func;
 212         msg->call_struct.info = info;
 213         msg->call_struct.wait = wait;
 214         msg->call_struct.pending = callmap;
 215         msg->call_struct.waitmask = callmap;
 216         msg->type = BFIN_IPI_CALL_FUNC;
 217
 218         for_each_cpu_mask(cpu, callmap) {
 219                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
 220                 spin_lock_irqsave(&msg_queue->lock, flags);
 221                 list_add_tail(&msg->list, &msg_queue->head);
 222                 spin_unlock_irqrestore(&msg_queue->lock, flags);
 223                 platform_send_ipi_cpu(cpu);
 224         }
 225         if (wait) {
 226                 while (!cpus_empty(msg->call_struct.waitmask))
 227                         blackfin_dcache_invalidate_range(
 228                                 (unsigned long)(&msg->call_struct.waitmask),
 229                                 (unsigned long)(&msg->call_struct.waitmask));
 230 #ifdef __ARCH_SYNC_CORE_DCACHE
 231                 /*
 232                  * Invalidate D cache in case shared data was changed by
 233                  * other processors to ensure cache coherence.
 234                  */
 235                 resync_core_dcache();
 236 #endif
 237                 kfree(msg);
 238         }
 239         return 0;
 240 }
 241 EXPORT_SYMBOL_GPL(smp_call_function);
 242
 243 int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
 244                                 int wait)
 245 {
 246         unsigned int cpu = cpuid;
 247         cpumask_t callmap;
 248         unsigned long flags;
 249         struct ipi_message_queue *msg_queue;
 250         struct ipi_message *msg;
 251
 252         if (cpu_is_offline(cpu))
 253                 return 0;
 254         cpus_clear(callmap);
 255         cpu_set(cpu, callmap);
 256
 257         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 258         if (!msg)
 259                 return -ENOMEM;
 260         INIT_LIST_HEAD(&msg->list);
 261         msg->call_struct.func = func;
 262         msg->call_struct.info = info;
 263         msg->call_struct.wait = wait;
 264         msg->call_struct.pending = callmap;
 265         msg->call_struct.waitmask = callmap;
 266         msg->type = BFIN_IPI_CALL_FUNC;
 267
 268         msg_queue = &per_cpu(ipi_msg_queue, cpu);
 269         spin_lock_irqsave(&msg_queue->lock, flags);
 270         list_add_tail(&msg->list, &msg_queue->head);
 271         spin_unlock_irqrestore(&msg_queue->lock, flags);
 272         platform_send_ipi_cpu(cpu);
 273
 274         if (wait) {
 275                 while (!cpus_empty(msg->call_struct.waitmask))
 276                         blackfin_dcache_invalidate_range(
 277                                 (unsigned long)(&msg->call_struct.waitmask),
 278                                 (unsigned long)(&msg->call_struct.waitmask));
 279 #ifdef __ARCH_SYNC_CORE_DCACHE
 280                 /*
 281                  * Invalidate D cache in case shared data was changed by
 282                  * other processors to ensure cache coherence.
 283                  */
 284                 resync_core_dcache();
 285 #endif
 286                 kfree(msg);
 287         }
 288         return 0;
 289 }
 290 EXPORT_SYMBOL_GPL(smp_call_function_single);
 291
 292 void smp_send_reschedule(int cpu)
 293 {
 294         unsigned long flags;
 295         struct ipi_message_queue *msg_queue;
 296         struct ipi_message *msg;
 297
 298         if (cpu_is_offline(cpu))
 299                 return;
 300
 301         msg = kzalloc(sizeof(*msg), GFP_ATOMIC);
 302         if (!msg)
 303                 return;
 304         INIT_LIST_HEAD(&msg->list);
 305         msg->type = BFIN_IPI_RESCHEDULE;
 306
 307         msg_queue = &per_cpu(ipi_msg_queue, cpu);
 308         spin_lock_irqsave(&msg_queue->lock, flags);
 309         list_add_tail(&msg->list, &msg_queue->head);
 310         spin_unlock_irqrestore(&msg_queue->lock, flags);
 311         platform_send_ipi_cpu(cpu);
 312
 313         return;
 314 }
 315
 316 void smp_send_stop(void)
 317 {
 318         unsigned int cpu;
 319         cpumask_t callmap;
 320         unsigned long flags;
 321         struct ipi_message_queue *msg_queue;
 322         struct ipi_message *msg;
 323
 324         callmap = cpu_online_map;
 325         cpu_clear(smp_processor_id(), callmap);
 326         if (cpus_empty(callmap))
 327                 return;
 328
 329         msg = kzalloc(sizeof(*msg), GFP_ATOMIC);
 330         if (!msg)
 331                 return;
 332         INIT_LIST_HEAD(&msg->list);
 333         msg->type = BFIN_IPI_CPU_STOP;
 334
 335         for_each_cpu_mask(cpu, callmap) {
 336                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
 337                 spin_lock_irqsave(&msg_queue->lock, flags);
 338                 list_add_tail(&msg->list, &msg_queue->head);
 339                 spin_unlock_irqrestore(&msg_queue->lock, flags);
 340                 platform_send_ipi_cpu(cpu);
 341         }
 342         return;
 343 }
 344
 345 int __cpuinit __cpu_up(unsigned int cpu)
 346 {
 347         int ret;
 348         static struct task_struct *idle;
 349
 350         if (idle)
 351                 free_task(idle);
 352
 353         idle = fork_idle(cpu);
 354         if (IS_ERR(idle)) {
 355                 printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
 356                 return PTR_ERR(idle);
 357         }
 358
 359         secondary_stack = task_stack_page(idle) + THREAD_SIZE;
 360
 361         ret = platform_boot_secondary(cpu, idle);
 362
 363         secondary_stack = NULL;
 364
 365         return ret;
 366 }
 367
 368 static void __cpuinit setup_secondary(unsigned int cpu)
 369 {
 370         unsigned long ilat;
 371
 372         bfin_write_IMASK(0);
 373         CSYNC();
 374         ilat = bfin_read_ILAT();
 375         CSYNC();
 376         bfin_write_ILAT(ilat);
 377         CSYNC();
 378
 379         /* Enable interrupt levels IVG7-15. IARs have been already
 380          * programmed by the boot CPU.  */
 381         bfin_irq_flags |= IMASK_IVG15 |
 382             IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 |
 383             IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW;
 384 }
 385
 386 void __cpuinit secondary_start_kernel(void)
 387 {
 388         unsigned int cpu = smp_processor_id();
 389         struct mm_struct *mm = &init_mm;
 390
 391         if (_bfin_swrst & SWRST_DBL_FAULT_B) {
 392                 printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
 393 #ifdef CONFIG_DEBUG_DOUBLEFAULT
 394                 printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
 395                         (int)init_saved_seqstat_coreb & SEQSTAT_EXCAUSE, init_saved_retx_coreb);
 396                 printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr_coreb);
 397                 printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr_coreb);
 398 #endif
 399                 printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
 400                         init_retx_coreb);
 401         }
 402
 403         /*
 404          * We want the D-cache to be enabled early, in case the atomic
 405          * support code emulates cache coherence (see
 406          * __ARCH_SYNC_CORE_DCACHE).
 407          */
 408         init_exception_vectors();
 409
 410         bfin_setup_caches(cpu);
 411
 412         local_irq_disable();
 413
 414         /* Attach the new idle task to the global mm. */
 415         atomic_inc(&mm->mm_users);
 416         atomic_inc(&mm->mm_count);
 417         current->active_mm = mm;
 418
 419         preempt_disable();
 420
 421         setup_secondary(cpu);
 422
 423         platform_secondary_init(cpu);
 424
 425         /* setup local core timer */
 426         bfin_local_timer_setup();
 427
 428         local_irq_enable();
 429
 430         /*
 431          * Calibrate loops per jiffy value.
 432          * IRQs need to be enabled here - D-cache can be invalidated
 433          * in timer irq handler, so core B can read correct jiffies.
 434          */
 435         calibrate_delay();
 436
 437         cpu_idle();
 438 }
 439
 440 void __init smp_prepare_boot_cpu(void)
 441 {
 442 }
 443
 444 void __init smp_prepare_cpus(unsigned int max_cpus)
 445 {
 446         platform_prepare_cpus(max_cpus);
 447         ipi_queue_init();
 448         platform_request_ipi(&ipi_handler);
 449 }
 450
 451 void __init smp_cpus_done(unsigned int max_cpus)
 452 {
 453         unsigned long bogosum = 0;
 454         unsigned int cpu;
 455
 456         for_each_online_cpu(cpu)
 457                 bogosum += loops_per_jiffy;
 458
 459         printk(KERN_INFO "SMP: Total of %d processors activated "
 460                "(%lu.%02lu BogoMIPS).\n",
 461                num_online_cpus(),
 462                bogosum / (500000/HZ),
 463                (bogosum / (5000/HZ)) % 100);
 464 }
 465
 466 void smp_icache_flush_range_others(unsigned long start, unsigned long end)
 467 {
 468         smp_flush_data.start = start;
 469         smp_flush_data.end = end;
 470
 471         if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 0))
 472                 printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
 473 }
 474 EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);
 475
 476 #ifdef __ARCH_SYNC_CORE_ICACHE
 477 void resync_core_icache(void)
 478 {
 479         unsigned int cpu = get_cpu();
 480         blackfin_invalidate_entire_icache();
 481         ++per_cpu(cpu_data, cpu).icache_invld_count;
 482         put_cpu();
 483 }
 484 EXPORT_SYMBOL(resync_core_icache);
 485 #endif
 486
 487 #ifdef __ARCH_SYNC_CORE_DCACHE
 488 unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));
 489
 490 void resync_core_dcache(void)
 491 {
 492         unsigned int cpu = get_cpu();
 493         blackfin_invalidate_entire_dcache();
 494         ++per_cpu(cpu_data, cpu).dcache_invld_count;
 495         put_cpu();
 496 }
 497 EXPORT_SYMBOL(resync_core_dcache);
 498 #endif
 499
 500 #ifdef CONFIG_HOTPLUG_CPU
 501 int __cpuexit __cpu_disable(void)
 502 {
 503         unsigned int cpu = smp_processor_id();
 504
 505         if (cpu == 0)
 506                 return -EPERM;
 507
 508         set_cpu_online(cpu, false);
 509         return 0;
 510 }
 511
 512 static DECLARE_COMPLETION(cpu_killed);
 513
 514 int __cpuexit __cpu_die(unsigned int cpu)
 515 {
 516         return wait_for_completion_timeout(&cpu_killed, 5000);
 517 }
 518
 519 void cpu_die(void)
 520 {
 521         complete(&cpu_killed);
 522
 523         atomic_dec(&init_mm.mm_users);
 524         atomic_dec(&init_mm.mm_count);
 525
 526         local_irq_disable();
 527         platform_cpu_die();
 528 }
 529 #endif