arch/blackfin/mach-common/smp.c

   1 /*
   2  * File:         arch/blackfin/kernel/smp.c
   3  * Author:       Philippe Gerum <rpm@xenomai.org>
   4  * IPI management based on arch/arm/kernel/smp.c.
   5  *
   6  *               Copyright 2007 Analog Devices Inc.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License as published by
  10  * the Free Software Foundation; either version 2 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * along with this program; if not, see the file COPYING, or write
  20  * to the Free Software Foundation, Inc.,
  21  * 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  22  */
  23
  24 #include <linux/module.h>
  25 #include <linux/delay.h>
  26 #include <linux/init.h>
  27 #include <linux/spinlock.h>
  28 #include <linux/sched.h>
  29 #include <linux/interrupt.h>
  30 #include <linux/cache.h>
  31 #include <linux/profile.h>
  32 #include <linux/errno.h>
  33 #include <linux/mm.h>
  34 #include <linux/cpu.h>
  35 #include <linux/smp.h>
  36 #include <linux/seq_file.h>
  37 #include <linux/irq.h>
  38 #include <asm/atomic.h>
  39 #include <asm/cacheflush.h>
  40 #include <asm/mmu_context.h>
  41 #include <asm/pgtable.h>
  42 #include <asm/pgalloc.h>
  43 #include <asm/processor.h>
  44 #include <asm/ptrace.h>
  45 #include <asm/cpu.h>
  46 #include <asm/time.h>
  47 #include <linux/err.h>
  48
  49 /*
  50  * Anomaly notes:
  51  * 05000120 - we always define corelock as 32-bit integer in L2
  52  */
  53 struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));
  54
  55 void __cpuinitdata *init_retx_coreb, *init_saved_retx_coreb,
  56         *init_saved_seqstat_coreb, *init_saved_icplb_fault_addr_coreb,
  57         *init_saved_dcplb_fault_addr_coreb;
  58
  59 cpumask_t cpu_possible_map;
  60 EXPORT_SYMBOL(cpu_possible_map);
  61
  62 cpumask_t cpu_online_map;
  63 EXPORT_SYMBOL(cpu_online_map);
  64
  65 #define BFIN_IPI_RESCHEDULE   0
  66 #define BFIN_IPI_CALL_FUNC    1
  67 #define BFIN_IPI_CPU_STOP     2
  68
  69 struct blackfin_flush_data {
  70         unsigned long start;
  71         unsigned long end;
  72 };
  73
  74 void *secondary_stack;
  75
  76
  77 struct smp_call_struct {
  78         void (*func)(void *info);
  79         void *info;
  80         int wait;
  81         cpumask_t pending;
  82         cpumask_t waitmask;
  83 };
  84
  85 static struct blackfin_flush_data smp_flush_data;
  86
  87 static DEFINE_SPINLOCK(stop_lock);
  88
  89 struct ipi_message {
  90         struct list_head list;
  91         unsigned long type;
  92         struct smp_call_struct call_struct;
  93 };
  94
  95 struct ipi_message_queue {
  96         struct list_head head;
  97         spinlock_t lock;
  98         unsigned long count;
  99 };
 100
 101 static DEFINE_PER_CPU(struct ipi_message_queue, ipi_msg_queue);
 102
 103 static void ipi_cpu_stop(unsigned int cpu)
 104 {
 105         spin_lock(&stop_lock);
 106         printk(KERN_CRIT "CPU%u: stopping\n", cpu);
 107         dump_stack();
 108         spin_unlock(&stop_lock);
 109
 110         cpu_clear(cpu, cpu_online_map);
 111
 112         local_irq_disable();
 113
 114         while (1)
 115                 SSYNC();
 116 }
 117
 118 static void ipi_flush_icache(void *info)
 119 {
 120         struct blackfin_flush_data *fdata = info;
 121
 122         /* Invalidate the memory holding the bounds of the flushed region. */
 123         blackfin_dcache_invalidate_range((unsigned long)fdata,
 124                                          (unsigned long)fdata + sizeof(*fdata));
 125
 126         blackfin_icache_flush_range(fdata->start, fdata->end);
 127 }
 128
 129 static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
 130 {
 131         int wait;
 132         void (*func)(void *info);
 133         void *info;
 134         func = msg->call_struct.func;
 135         info = msg->call_struct.info;
 136         wait = msg->call_struct.wait;
 137         cpu_clear(cpu, msg->call_struct.pending);
 138         func(info);
 139         if (wait)
 140                 cpu_clear(cpu, msg->call_struct.waitmask);
 141         else
 142                 kfree(msg);
 143 }
 144
 145 static irqreturn_t ipi_handler(int irq, void *dev_instance)
 146 {
 147         struct ipi_message *msg;
 148         struct ipi_message_queue *msg_queue;
 149         unsigned int cpu = smp_processor_id();
 150
 151         platform_clear_ipi(cpu);
 152
 153         msg_queue = &__get_cpu_var(ipi_msg_queue);
 154         msg_queue->count++;
 155
 156         spin_lock(&msg_queue->lock);
 157         while (!list_empty(&msg_queue->head)) {
 158                 msg = list_entry(msg_queue->head.next, typeof(*msg), list);
 159                 list_del(&msg->list);
 160                 switch (msg->type) {
 161                 case BFIN_IPI_RESCHEDULE:
 162                         /* That's the easiest one; leave it to
 163                          * return_from_int. */
 164                         kfree(msg);
 165                         break;
 166                 case BFIN_IPI_CALL_FUNC:
 167                         spin_unlock(&msg_queue->lock);
 168                         ipi_call_function(cpu, msg);
 169                         spin_lock(&msg_queue->lock);
 170                         break;
 171                 case BFIN_IPI_CPU_STOP:
 172                         spin_unlock(&msg_queue->lock);
 173                         ipi_cpu_stop(cpu);
 174                         spin_lock(&msg_queue->lock);
 175                         kfree(msg);
 176                         break;
 177                 default:
 178                         printk(KERN_CRIT "CPU%u: Unknown IPI message \
 179                         0x%lx\n", cpu, msg->type);
 180                         kfree(msg);
 181                         break;
 182                 }
 183         }
 184         spin_unlock(&msg_queue->lock);
 185         return IRQ_HANDLED;
 186 }
 187
 188 static void ipi_queue_init(void)
 189 {
 190         unsigned int cpu;
 191         struct ipi_message_queue *msg_queue;
 192         for_each_possible_cpu(cpu) {
 193                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
 194                 INIT_LIST_HEAD(&msg_queue->head);
 195                 spin_lock_init(&msg_queue->lock);
 196                 msg_queue->count = 0;
 197         }
 198 }
 199
 200 int smp_call_function(void (*func)(void *info), void *info, int wait)
 201 {
 202         unsigned int cpu;
 203         cpumask_t callmap;
 204         unsigned long flags;
 205         struct ipi_message_queue *msg_queue;
 206         struct ipi_message *msg;
 207
 208         callmap = cpu_online_map;
 209         cpu_clear(smp_processor_id(), callmap);
 210         if (cpus_empty(callmap))
 211                 return 0;
 212
 213         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 214         if (!msg)
 215                 return -ENOMEM;
 216         INIT_LIST_HEAD(&msg->list);
 217         msg->call_struct.func = func;
 218         msg->call_struct.info = info;
 219         msg->call_struct.wait = wait;
 220         msg->call_struct.pending = callmap;
 221         msg->call_struct.waitmask = callmap;
 222         msg->type = BFIN_IPI_CALL_FUNC;
 223
 224         for_each_cpu_mask(cpu, callmap) {
 225                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
 226                 spin_lock_irqsave(&msg_queue->lock, flags);
 227                 list_add_tail(&msg->list, &msg_queue->head);
 228                 spin_unlock_irqrestore(&msg_queue->lock, flags);
 229                 platform_send_ipi_cpu(cpu);
 230         }
 231         if (wait) {
 232                 while (!cpus_empty(msg->call_struct.waitmask))
 233                         blackfin_dcache_invalidate_range(
 234                                 (unsigned long)(&msg->call_struct.waitmask),
 235                                 (unsigned long)(&msg->call_struct.waitmask));
 236                 kfree(msg);
 237         }
 238         return 0;
 239 }
 240 EXPORT_SYMBOL_GPL(smp_call_function);
 241
 242 int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
 243                                 int wait)
 244 {
 245         unsigned int cpu = cpuid;
 246         cpumask_t callmap;
 247         unsigned long flags;
 248         struct ipi_message_queue *msg_queue;
 249         struct ipi_message *msg;
 250
 251         if (cpu_is_offline(cpu))
 252                 return 0;
 253         cpus_clear(callmap);
 254         cpu_set(cpu, callmap);
 255
 256         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 257         if (!msg)
 258                 return -ENOMEM;
 259         INIT_LIST_HEAD(&msg->list);
 260         msg->call_struct.func = func;
 261         msg->call_struct.info = info;
 262         msg->call_struct.wait = wait;
 263         msg->call_struct.pending = callmap;
 264         msg->call_struct.waitmask = callmap;
 265         msg->type = BFIN_IPI_CALL_FUNC;
 266
 267         msg_queue = &per_cpu(ipi_msg_queue, cpu);
 268         spin_lock_irqsave(&msg_queue->lock, flags);
 269         list_add_tail(&msg->list, &msg_queue->head);
 270         spin_unlock_irqrestore(&msg_queue->lock, flags);
 271         platform_send_ipi_cpu(cpu);
 272
 273         if (wait) {
 274                 while (!cpus_empty(msg->call_struct.waitmask))
 275                         blackfin_dcache_invalidate_range(
 276                                 (unsigned long)(&msg->call_struct.waitmask),
 277                                 (unsigned long)(&msg->call_struct.waitmask));
 278                 kfree(msg);
 279         }
 280         return 0;
 281 }
 282 EXPORT_SYMBOL_GPL(smp_call_function_single);
 283
 284 void smp_send_reschedule(int cpu)
 285 {
 286         unsigned long flags;
 287         struct ipi_message_queue *msg_queue;
 288         struct ipi_message *msg;
 289
 290         if (cpu_is_offline(cpu))
 291                 return;
 292
 293         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 294         if (!msg)
 295                 return;
 296         memset(msg, 0, sizeof(msg));
 297         INIT_LIST_HEAD(&msg->list);
 298         msg->type = BFIN_IPI_RESCHEDULE;
 299
 300         msg_queue = &per_cpu(ipi_msg_queue, cpu);
 301         spin_lock_irqsave(&msg_queue->lock, flags);
 302         list_add_tail(&msg->list, &msg_queue->head);
 303         spin_unlock_irqrestore(&msg_queue->lock, flags);
 304         platform_send_ipi_cpu(cpu);
 305
 306         return;
 307 }
 308
 309 void smp_send_stop(void)
 310 {
 311         unsigned int cpu;
 312         cpumask_t callmap;
 313         unsigned long flags;
 314         struct ipi_message_queue *msg_queue;
 315         struct ipi_message *msg;
 316
 317         callmap = cpu_online_map;
 318         cpu_clear(smp_processor_id(), callmap);
 319         if (cpus_empty(callmap))
 320                 return;
 321
 322         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 323         if (!msg)
 324                 return;
 325         memset(msg, 0, sizeof(msg));
 326         INIT_LIST_HEAD(&msg->list);
 327         msg->type = BFIN_IPI_CPU_STOP;
 328
 329         for_each_cpu_mask(cpu, callmap) {
 330                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
 331                 spin_lock_irqsave(&msg_queue->lock, flags);
 332                 list_add_tail(&msg->list, &msg_queue->head);
 333                 spin_unlock_irqrestore(&msg_queue->lock, flags);
 334                 platform_send_ipi_cpu(cpu);
 335         }
 336         return;
 337 }
 338
 339 int __cpuinit __cpu_up(unsigned int cpu)
 340 {
 341         struct task_struct *idle;
 342         int ret;
 343
 344         idle = fork_idle(cpu);
 345         if (IS_ERR(idle)) {
 346                 printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
 347                 return PTR_ERR(idle);
 348         }
 349
 350         secondary_stack = task_stack_page(idle) + THREAD_SIZE;
 351         smp_wmb();
 352
 353         ret = platform_boot_secondary(cpu, idle);
 354
 355         if (ret) {
 356                 cpu_clear(cpu, cpu_present_map);
 357                 printk(KERN_CRIT "CPU%u: processor failed to boot (%d)\n", cpu, ret);
 358                 free_task(idle);
 359         } else
 360                 cpu_set(cpu, cpu_online_map);
 361
 362         secondary_stack = NULL;
 363
 364         return ret;
 365 }
 366
 367 static void __cpuinit setup_secondary(unsigned int cpu)
 368 {
 369 #if !defined(CONFIG_TICKSOURCE_GPTMR0)
 370         struct irq_desc *timer_desc;
 371 #endif
 372         unsigned long ilat;
 373
 374         bfin_write_IMASK(0);
 375         CSYNC();
 376         ilat = bfin_read_ILAT();
 377         CSYNC();
 378         bfin_write_ILAT(ilat);
 379         CSYNC();
 380
 381         /* Enable interrupt levels IVG7-15. IARs have been already
 382          * programmed by the boot CPU.  */
 383         bfin_irq_flags |= IMASK_IVG15 |
 384             IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 |
 385             IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW;
 386
 387 #if defined(CONFIG_TICKSOURCE_GPTMR0)
 388         /* Power down the core timer, just to play safe. */
 389         bfin_write_TCNTL(0);
 390
 391         /* system timer0 has been setup by CoreA. */
 392 #else
 393         timer_desc = irq_desc + IRQ_CORETMR;
 394         setup_core_timer();
 395         timer_desc->chip->enable(IRQ_CORETMR);
 396 #endif
 397 }
 398
 399 void __cpuinit secondary_start_kernel(void)
 400 {
 401         unsigned int cpu = smp_processor_id();
 402         struct mm_struct *mm = &init_mm;
 403
 404         if (_bfin_swrst & SWRST_DBL_FAULT_B) {
 405                 printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
 406 #ifdef CONFIG_DEBUG_DOUBLEFAULT
 407                 printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
 408                         (int)init_saved_seqstat_coreb & SEQSTAT_EXCAUSE, init_saved_retx_coreb);
 409                 printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr_coreb);
 410                 printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr_coreb);
 411 #endif
 412                 printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
 413                         init_retx_coreb);
 414         }
 415
 416         /*
 417          * We want the D-cache to be enabled early, in case the atomic
 418          * support code emulates cache coherence (see
 419          * __ARCH_SYNC_CORE_DCACHE).
 420          */
 421         init_exception_vectors();
 422
 423         bfin_setup_caches(cpu);
 424
 425         local_irq_disable();
 426
 427         /* Attach the new idle task to the global mm. */
 428         atomic_inc(&mm->mm_users);
 429         atomic_inc(&mm->mm_count);
 430         current->active_mm = mm;
 431         BUG_ON(current->mm);    /* Can't be, but better be safe than sorry. */
 432
 433         preempt_disable();
 434
 435         setup_secondary(cpu);
 436
 437         local_irq_enable();
 438
 439         platform_secondary_init(cpu);
 440
 441         cpu_idle();
 442 }
 443
 444 void __init smp_prepare_boot_cpu(void)
 445 {
 446 }
 447
 448 void __init smp_prepare_cpus(unsigned int max_cpus)
 449 {
 450         platform_prepare_cpus(max_cpus);
 451         ipi_queue_init();
 452         platform_request_ipi(&ipi_handler);
 453 }
 454
 455 void __init smp_cpus_done(unsigned int max_cpus)
 456 {
 457         unsigned long bogosum = 0;
 458         unsigned int cpu;
 459
 460         for_each_online_cpu(cpu)
 461                 bogosum += loops_per_jiffy;
 462
 463         printk(KERN_INFO "SMP: Total of %d processors activated "
 464                "(%lu.%02lu BogoMIPS).\n",
 465                num_online_cpus(),
 466                bogosum / (500000/HZ),
 467                (bogosum / (5000/HZ)) % 100);
 468 }
 469
 470 void smp_icache_flush_range_others(unsigned long start, unsigned long end)
 471 {
 472         smp_flush_data.start = start;
 473         smp_flush_data.end = end;
 474
 475         if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 0))
 476                 printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
 477 }
 478 EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);
 479
 480 #ifdef __ARCH_SYNC_CORE_ICACHE
 481 void resync_core_icache(void)
 482 {
 483         unsigned int cpu = get_cpu();
 484         blackfin_invalidate_entire_icache();
 485         ++per_cpu(cpu_data, cpu).icache_invld_count;
 486         put_cpu();
 487 }
 488 EXPORT_SYMBOL(resync_core_icache);
 489 #endif
 490
 491 #ifdef __ARCH_SYNC_CORE_DCACHE
 492 unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));
 493
 494 void resync_core_dcache(void)
 495 {
 496         unsigned int cpu = get_cpu();
 497         blackfin_invalidate_entire_dcache();
 498         ++per_cpu(cpu_data, cpu).dcache_invld_count;
 499         put_cpu();
 500 }
 501 EXPORT_SYMBOL(resync_core_dcache);
 502 #endif