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   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 <linux/err.h>
  47
  48 struct corelock_slot corelock __attribute__ ((__section__(".l2.bss")));
  49
  50 void __cpuinitdata *init_retx_coreb, *init_saved_retx_coreb,
  51         *init_saved_seqstat_coreb, *init_saved_icplb_fault_addr_coreb,
  52         *init_saved_dcplb_fault_addr_coreb;
  53
  54 cpumask_t cpu_possible_map;
  55 EXPORT_SYMBOL(cpu_possible_map);
  56
  57 cpumask_t cpu_online_map;
  58 EXPORT_SYMBOL(cpu_online_map);
  59
  60 #define BFIN_IPI_RESCHEDULE   0
  61 #define BFIN_IPI_CALL_FUNC    1
  62 #define BFIN_IPI_CPU_STOP     2
  63
  64 struct blackfin_flush_data {
  65         unsigned long start;
  66         unsigned long end;
  67 };
  68
  69 void *secondary_stack;
  70
  71
  72 struct smp_call_struct {
  73         void (*func)(void *info);
  74         void *info;
  75         int wait;
  76         cpumask_t pending;
  77         cpumask_t waitmask;
  78 };
  79
  80 static struct blackfin_flush_data smp_flush_data;
  81
  82 static DEFINE_SPINLOCK(stop_lock);
  83
  84 struct ipi_message {
  85         struct list_head list;
  86         unsigned long type;
  87         struct smp_call_struct call_struct;
  88 };
  89
  90 struct ipi_message_queue {
  91         struct list_head head;
  92         spinlock_t lock;
  93         unsigned long count;
  94 };
  95
  96 static DEFINE_PER_CPU(struct ipi_message_queue, ipi_msg_queue);
  97
  98 static void ipi_cpu_stop(unsigned int cpu)
  99 {
 100         spin_lock(&stop_lock);
 101         printk(KERN_CRIT "CPU%u: stopping\n", cpu);
 102         dump_stack();
 103         spin_unlock(&stop_lock);
 104
 105         cpu_clear(cpu, cpu_online_map);
 106
 107         local_irq_disable();
 108
 109         while (1)
 110                 SSYNC();
 111 }
 112
 113 static void ipi_flush_icache(void *info)
 114 {
 115         struct blackfin_flush_data *fdata = info;
 116
 117         /* Invalidate the memory holding the bounds of the flushed region. */
 118         blackfin_dcache_invalidate_range((unsigned long)fdata,
 119                                          (unsigned long)fdata + sizeof(*fdata));
 120
 121         blackfin_icache_flush_range(fdata->start, fdata->end);
 122 }
 123
 124 static void ipi_call_function(unsigned int cpu, struct ipi_message *msg)
 125 {
 126         int wait;
 127         void (*func)(void *info);
 128         void *info;
 129         func = msg->call_struct.func;
 130         info = msg->call_struct.info;
 131         wait = msg->call_struct.wait;
 132         cpu_clear(cpu, msg->call_struct.pending);
 133         func(info);
 134         if (wait)
 135                 cpu_clear(cpu, msg->call_struct.waitmask);
 136         else
 137                 kfree(msg);
 138 }
 139
 140 static irqreturn_t ipi_handler(int irq, void *dev_instance)
 141 {
 142         struct ipi_message *msg, *mg;
 143         struct ipi_message_queue *msg_queue;
 144         unsigned int cpu = smp_processor_id();
 145
 146         platform_clear_ipi(cpu);
 147
 148         msg_queue = &__get_cpu_var(ipi_msg_queue);
 149         msg_queue->count++;
 150
 151         spin_lock(&msg_queue->lock);
 152         list_for_each_entry_safe(msg, mg, &msg_queue->head, 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                         ipi_call_function(cpu, msg);
 162                         break;
 163                 case BFIN_IPI_CPU_STOP:
 164                         ipi_cpu_stop(cpu);
 165                         kfree(msg);
 166                         break;
 167                 default:
 168                         printk(KERN_CRIT "CPU%u: Unknown IPI message \
 169                         0x%lx\n", cpu, msg->type);
 170                         kfree(msg);
 171                         break;
 172                 }
 173         }
 174         spin_unlock(&msg_queue->lock);
 175         return IRQ_HANDLED;
 176 }
 177
 178 static void ipi_queue_init(void)
 179 {
 180         unsigned int cpu;
 181         struct ipi_message_queue *msg_queue;
 182         for_each_possible_cpu(cpu) {
 183                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
 184                 INIT_LIST_HEAD(&msg_queue->head);
 185                 spin_lock_init(&msg_queue->lock);
 186                 msg_queue->count = 0;
 187         }
 188 }
 189
 190 int smp_call_function(void (*func)(void *info), void *info, int wait)
 191 {
 192         unsigned int cpu;
 193         cpumask_t callmap;
 194         unsigned long flags;
 195         struct ipi_message_queue *msg_queue;
 196         struct ipi_message *msg;
 197
 198         callmap = cpu_online_map;
 199         cpu_clear(smp_processor_id(), callmap);
 200         if (cpus_empty(callmap))
 201                 return 0;
 202
 203         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 204         INIT_LIST_HEAD(&msg->list);
 205         msg->call_struct.func = func;
 206         msg->call_struct.info = info;
 207         msg->call_struct.wait = wait;
 208         msg->call_struct.pending = callmap;
 209         msg->call_struct.waitmask = callmap;
 210         msg->type = BFIN_IPI_CALL_FUNC;
 211
 212         for_each_cpu_mask(cpu, callmap) {
 213                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
 214                 spin_lock_irqsave(&msg_queue->lock, flags);
 215                 list_add(&msg->list, &msg_queue->head);
 216                 spin_unlock_irqrestore(&msg_queue->lock, flags);
 217                 platform_send_ipi_cpu(cpu);
 218         }
 219         if (wait) {
 220                 while (!cpus_empty(msg->call_struct.waitmask))
 221                         blackfin_dcache_invalidate_range(
 222                                 (unsigned long)(&msg->call_struct.waitmask),
 223                                 (unsigned long)(&msg->call_struct.waitmask));
 224                 kfree(msg);
 225         }
 226         return 0;
 227 }
 228 EXPORT_SYMBOL_GPL(smp_call_function);
 229
 230 int smp_call_function_single(int cpuid, void (*func) (void *info), void *info,
 231                                 int wait)
 232 {
 233         unsigned int cpu = cpuid;
 234         cpumask_t callmap;
 235         unsigned long flags;
 236         struct ipi_message_queue *msg_queue;
 237         struct ipi_message *msg;
 238
 239         if (cpu_is_offline(cpu))
 240                 return 0;
 241         cpus_clear(callmap);
 242         cpu_set(cpu, callmap);
 243
 244         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 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(&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 = kmalloc(sizeof(*msg), GFP_ATOMIC);
 280         memset(msg, 0, sizeof(msg));
 281         INIT_LIST_HEAD(&msg->list);
 282         msg->type = BFIN_IPI_RESCHEDULE;
 283
 284         msg_queue = &per_cpu(ipi_msg_queue, cpu);
 285         spin_lock_irqsave(&msg_queue->lock, flags);
 286         list_add(&msg->list, &msg_queue->head);
 287         spin_unlock_irqrestore(&msg_queue->lock, flags);
 288         platform_send_ipi_cpu(cpu);
 289
 290         return;
 291 }
 292
 293 void smp_send_stop(void)
 294 {
 295         unsigned int cpu;
 296         cpumask_t callmap;
 297         unsigned long flags;
 298         struct ipi_message_queue *msg_queue;
 299         struct ipi_message *msg;
 300
 301         callmap = cpu_online_map;
 302         cpu_clear(smp_processor_id(), callmap);
 303         if (cpus_empty(callmap))
 304                 return;
 305
 306         msg = kmalloc(sizeof(*msg), GFP_ATOMIC);
 307         memset(msg, 0, sizeof(msg));
 308         INIT_LIST_HEAD(&msg->list);
 309         msg->type = BFIN_IPI_CPU_STOP;
 310
 311         for_each_cpu_mask(cpu, callmap) {
 312                 msg_queue = &per_cpu(ipi_msg_queue, cpu);
 313                 spin_lock_irqsave(&msg_queue->lock, flags);
 314                 list_add(&msg->list, &msg_queue->head);
 315                 spin_unlock_irqrestore(&msg_queue->lock, flags);
 316                 platform_send_ipi_cpu(cpu);
 317         }
 318         return;
 319 }
 320
 321 int __cpuinit __cpu_up(unsigned int cpu)
 322 {
 323         struct task_struct *idle;
 324         int ret;
 325
 326         idle = fork_idle(cpu);
 327         if (IS_ERR(idle)) {
 328                 printk(KERN_ERR "CPU%u: fork() failed\n", cpu);
 329                 return PTR_ERR(idle);
 330         }
 331
 332         secondary_stack = task_stack_page(idle) + THREAD_SIZE;
 333         smp_wmb();
 334
 335         ret = platform_boot_secondary(cpu, idle);
 336
 337         if (ret) {
 338                 cpu_clear(cpu, cpu_present_map);
 339                 printk(KERN_CRIT "CPU%u: processor failed to boot (%d)\n", cpu, ret);
 340                 free_task(idle);
 341         } else
 342                 cpu_set(cpu, cpu_online_map);
 343
 344         secondary_stack = NULL;
 345
 346         return ret;
 347 }
 348
 349 static void __cpuinit setup_secondary(unsigned int cpu)
 350 {
 351 #if !(defined(CONFIG_TICK_SOURCE_SYSTMR0) || defined(CONFIG_IPIPE))
 352         struct irq_desc *timer_desc;
 353 #endif
 354         unsigned long ilat;
 355
 356         bfin_write_IMASK(0);
 357         CSYNC();
 358         ilat = bfin_read_ILAT();
 359         CSYNC();
 360         bfin_write_ILAT(ilat);
 361         CSYNC();
 362
 363         /* Reserve the PDA space for the secondary CPU. */
 364         reserve_pda();
 365
 366         /* Enable interrupt levels IVG7-15. IARs have been already
 367          * programmed by the boot CPU.  */
 368         bfin_irq_flags |= IMASK_IVG15 |
 369             IMASK_IVG14 | IMASK_IVG13 | IMASK_IVG12 | IMASK_IVG11 |
 370             IMASK_IVG10 | IMASK_IVG9 | IMASK_IVG8 | IMASK_IVG7 | IMASK_IVGHW;
 371
 372 #if defined(CONFIG_TICK_SOURCE_SYSTMR0) || defined(CONFIG_IPIPE)
 373         /* Power down the core timer, just to play safe. */
 374         bfin_write_TCNTL(0);
 375
 376         /* system timer0 has been setup by CoreA. */
 377 #else
 378         timer_desc = irq_desc + IRQ_CORETMR;
 379         setup_core_timer();
 380         timer_desc->chip->enable(IRQ_CORETMR);
 381 #endif
 382 }
 383
 384 void __cpuinit secondary_start_kernel(void)
 385 {
 386         unsigned int cpu = smp_processor_id();
 387         struct mm_struct *mm = &init_mm;
 388
 389         if (_bfin_swrst & SWRST_DBL_FAULT_B) {
 390                 printk(KERN_EMERG "CoreB Recovering from DOUBLE FAULT event\n");
 391 #ifdef CONFIG_DEBUG_DOUBLEFAULT
 392                 printk(KERN_EMERG " While handling exception (EXCAUSE = 0x%x) at %pF\n",
 393                         (int)init_saved_seqstat_coreb & SEQSTAT_EXCAUSE, init_saved_retx_coreb);
 394                 printk(KERN_NOTICE "   DCPLB_FAULT_ADDR: %pF\n", init_saved_dcplb_fault_addr_coreb);
 395                 printk(KERN_NOTICE "   ICPLB_FAULT_ADDR: %pF\n", init_saved_icplb_fault_addr_coreb);
 396 #endif
 397                 printk(KERN_NOTICE " The instruction at %pF caused a double exception\n",
 398                         init_retx_coreb);
 399         }
 400
 401         /*
 402          * We want the D-cache to be enabled early, in case the atomic
 403          * support code emulates cache coherence (see
 404          * __ARCH_SYNC_CORE_DCACHE).
 405          */
 406         init_exception_vectors();
 407
 408         bfin_setup_caches(cpu);
 409
 410         local_irq_disable();
 411
 412         /* Attach the new idle task to the global mm. */
 413         atomic_inc(&mm->mm_users);
 414         atomic_inc(&mm->mm_count);
 415         current->active_mm = mm;
 416         BUG_ON(current->mm);    /* Can't be, but better be safe than sorry. */
 417
 418         preempt_disable();
 419
 420         setup_secondary(cpu);
 421
 422         local_irq_enable();
 423
 424         platform_secondary_init(cpu);
 425
 426         cpu_idle();
 427 }
 428
 429 void __init smp_prepare_boot_cpu(void)
 430 {
 431 }
 432
 433 void __init smp_prepare_cpus(unsigned int max_cpus)
 434 {
 435         platform_prepare_cpus(max_cpus);
 436         ipi_queue_init();
 437         platform_request_ipi(&ipi_handler);
 438 }
 439
 440 void __init smp_cpus_done(unsigned int max_cpus)
 441 {
 442         unsigned long bogosum = 0;
 443         unsigned int cpu;
 444
 445         for_each_online_cpu(cpu)
 446                 bogosum += per_cpu(cpu_data, cpu).loops_per_jiffy;
 447
 448         printk(KERN_INFO "SMP: Total of %d processors activated "
 449                "(%lu.%02lu BogoMIPS).\n",
 450                num_online_cpus(),
 451                bogosum / (500000/HZ),
 452                (bogosum / (5000/HZ)) % 100);
 453 }
 454
 455 void smp_icache_flush_range_others(unsigned long start, unsigned long end)
 456 {
 457         smp_flush_data.start = start;
 458         smp_flush_data.end = end;
 459
 460         if (smp_call_function(&ipi_flush_icache, &smp_flush_data, 1))
 461                 printk(KERN_WARNING "SMP: failed to run I-cache flush request on other CPUs\n");
 462 }
 463 EXPORT_SYMBOL_GPL(smp_icache_flush_range_others);
 464
 465 #ifdef __ARCH_SYNC_CORE_DCACHE
 466 unsigned long barrier_mask __attribute__ ((__section__(".l2.bss")));
 467
 468 void resync_core_dcache(void)
 469 {
 470         unsigned int cpu = get_cpu();
 471         blackfin_invalidate_entire_dcache();
 472         ++per_cpu(cpu_data, cpu).dcache_invld_count;
 473         put_cpu();
 474 }
 475 EXPORT_SYMBOL(resync_core_dcache);
 476 #endif