1 /* 2 ** SMP Support 3 ** 4 ** Copyright (C) 1999 Walt Drummond <drummond@valinux.com> 5 ** Copyright (C) 1999 David Mosberger-Tang <davidm@hpl.hp.com> 6 ** Copyright (C) 2001,2004 Grant Grundler <grundler@parisc-linux.org> 7 ** 8 ** Lots of stuff stolen from arch/alpha/kernel/smp.c 9 ** ...and then parisc stole from arch/ia64/kernel/smp.c. Thanks David! :^) 10 ** 11 ** Thanks to John Curry and Ullas Ponnadi. I learned alot from their work. 12 ** -grant (1/12/2001) 13 ** 14 ** This program is free software; you can redistribute it and/or modify 15 ** it under the terms of the GNU General Public License as published by 16 ** the Free Software Foundation; either version 2 of the License, or 17 ** (at your option) any later version. 18 */ 19 #undef ENTRY_SYS_CPUS /* syscall support for iCOD-like functionality */ 20 21 #include <linux/autoconf.h> 22 23 #include <linux/types.h> 24 #include <linux/spinlock.h> 25 #include <linux/slab.h> 26 27 #include <linux/kernel.h> 28 #include <linux/module.h> 29 #include <linux/sched.h> 30 #include <linux/init.h> 31 #include <linux/interrupt.h> 32 #include <linux/smp.h> 33 #include <linux/kernel_stat.h> 34 #include <linux/mm.h> 35 #include <linux/delay.h> 36 #include <linux/bitops.h> 37 38 #include <asm/system.h> 39 #include <asm/atomic.h> 40 #include <asm/current.h> 41 #include <asm/delay.h> 42 #include <asm/pgalloc.h> /* for flush_tlb_all() proto/macro */ 43 44 #include <asm/io.h> 45 #include <asm/irq.h> /* for CPU_IRQ_REGION and friends */ 46 #include <asm/mmu_context.h> 47 #include <asm/page.h> 48 #include <asm/pgtable.h> 49 #include <asm/pgalloc.h> 50 #include <asm/processor.h> 51 #include <asm/ptrace.h> 52 #include <asm/unistd.h> 53 #include <asm/cacheflush.h> 54 55 #define kDEBUG 0 56 57 DEFINE_SPINLOCK(smp_lock); 58 59 volatile struct task_struct *smp_init_current_idle_task; 60 61 static volatile int cpu_now_booting = 0; /* track which CPU is booting */ 62 63 static int parisc_max_cpus = 1; 64 65 /* online cpus are ones that we've managed to bring up completely 66 * possible cpus are all valid cpu 67 * present cpus are all detected cpu 68 * 69 * On startup we bring up the "possible" cpus. Since we discover 70 * CPUs later, we add them as hotplug, so the possible cpu mask is 71 * empty in the beginning. 72 */ 73 74 cpumask_t cpu_online_map = CPU_MASK_NONE; /* Bitmap of online CPUs */ 75 cpumask_t cpu_possible_map = CPU_MASK_ALL; /* Bitmap of Present CPUs */ 76 77 EXPORT_SYMBOL(cpu_online_map); 78 EXPORT_SYMBOL(cpu_possible_map); 79 80 81 struct smp_call_struct { 82 void (*func) (void *info); 83 void *info; 84 long wait; 85 atomic_t unstarted_count; 86 atomic_t unfinished_count; 87 }; 88 static volatile struct smp_call_struct *smp_call_function_data; 89 90 enum ipi_message_type { 91 IPI_NOP=0, 92 IPI_RESCHEDULE=1, 93 IPI_CALL_FUNC, 94 IPI_CPU_START, 95 IPI_CPU_STOP, 96 IPI_CPU_TEST 97 }; 98 99 100 /********** SMP inter processor interrupt and communication routines */ 101 102 #undef PER_CPU_IRQ_REGION 103 #ifdef PER_CPU_IRQ_REGION 104 /* XXX REVISIT Ignore for now. 105 ** *May* need this "hook" to register IPI handler 106 ** once we have perCPU ExtIntr switch tables. 107 */ 108 static void 109 ipi_init(int cpuid) 110 { 111 112 /* If CPU is present ... */ 113 #ifdef ENTRY_SYS_CPUS 114 /* *and* running (not stopped) ... */ 115 #error iCOD support wants state checked here. 116 #endif 117 118 #error verify IRQ_OFFSET(IPI_IRQ) is ipi_interrupt() in new IRQ region 119 120 if(cpu_online(cpuid) ) 121 { 122 switch_to_idle_task(current); 123 } 124 125 return; 126 } 127 #endif 128 129 130 /* 131 ** Yoink this CPU from the runnable list... 132 ** 133 */ 134 static void 135 halt_processor(void) 136 { 137 #ifdef ENTRY_SYS_CPUS 138 #error halt_processor() needs rework 139 /* 140 ** o migrate I/O interrupts off this CPU. 141 ** o leave IPI enabled - __cli() will disable IPI. 142 ** o leave CPU in online map - just change the state 143 */ 144 cpu_data[this_cpu].state = STATE_STOPPED; 145 mark_bh(IPI_BH); 146 #else 147 /* REVISIT : redirect I/O Interrupts to another CPU? */ 148 /* REVISIT : does PM *know* this CPU isn't available? */ 149 cpu_clear(smp_processor_id(), cpu_online_map); 150 local_irq_disable(); 151 for (;;) 152 ; 153 #endif 154 } 155 156 157 irqreturn_t 158 ipi_interrupt(int irq, void *dev_id, struct pt_regs *regs) 159 { 160 int this_cpu = smp_processor_id(); 161 struct cpuinfo_parisc *p = &cpu_data[this_cpu]; 162 unsigned long ops; 163 unsigned long flags; 164 165 /* Count this now; we may make a call that never returns. */ 166 p->ipi_count++; 167 168 mb(); /* Order interrupt and bit testing. */ 169 170 for (;;) { 171 spin_lock_irqsave(&(p->lock),flags); 172 ops = p->pending_ipi; 173 p->pending_ipi = 0; 174 spin_unlock_irqrestore(&(p->lock),flags); 175 176 mb(); /* Order bit clearing and data access. */ 177 178 if (!ops) 179 break; 180 181 while (ops) { 182 unsigned long which = ffz(~ops); 183 184 switch (which) { 185 case IPI_RESCHEDULE: 186 #if (kDEBUG>=100) 187 printk(KERN_DEBUG "CPU%d IPI_RESCHEDULE\n",this_cpu); 188 #endif /* kDEBUG */ 189 ops &= ~(1 << IPI_RESCHEDULE); 190 /* 191 * Reschedule callback. Everything to be 192 * done is done by the interrupt return path. 193 */ 194 break; 195 196 case IPI_CALL_FUNC: 197 #if (kDEBUG>=100) 198 printk(KERN_DEBUG "CPU%d IPI_CALL_FUNC\n",this_cpu); 199 #endif /* kDEBUG */ 200 ops &= ~(1 << IPI_CALL_FUNC); 201 { 202 volatile struct smp_call_struct *data; 203 void (*func)(void *info); 204 void *info; 205 int wait; 206 207 data = smp_call_function_data; 208 func = data->func; 209 info = data->info; 210 wait = data->wait; 211 212 mb(); 213 atomic_dec ((atomic_t *)&data->unstarted_count); 214 215 /* At this point, *data can't 216 * be relied upon. 217 */ 218 219 (*func)(info); 220 221 /* Notify the sending CPU that the 222 * task is done. 223 */ 224 mb(); 225 if (wait) 226 atomic_dec ((atomic_t *)&data->unfinished_count); 227 } 228 break; 229 230 case IPI_CPU_START: 231 #if (kDEBUG>=100) 232 printk(KERN_DEBUG "CPU%d IPI_CPU_START\n",this_cpu); 233 #endif /* kDEBUG */ 234 ops &= ~(1 << IPI_CPU_START); 235 #ifdef ENTRY_SYS_CPUS 236 p->state = STATE_RUNNING; 237 #endif 238 break; 239 240 case IPI_CPU_STOP: 241 #if (kDEBUG>=100) 242 printk(KERN_DEBUG "CPU%d IPI_CPU_STOP\n",this_cpu); 243 #endif /* kDEBUG */ 244 ops &= ~(1 << IPI_CPU_STOP); 245 #ifdef ENTRY_SYS_CPUS 246 #else 247 halt_processor(); 248 #endif 249 break; 250 251 case IPI_CPU_TEST: 252 #if (kDEBUG>=100) 253 printk(KERN_DEBUG "CPU%d is alive!\n",this_cpu); 254 #endif /* kDEBUG */ 255 ops &= ~(1 << IPI_CPU_TEST); 256 break; 257 258 default: 259 printk(KERN_CRIT "Unknown IPI num on CPU%d: %lu\n", 260 this_cpu, which); 261 ops &= ~(1 << which); 262 return IRQ_NONE; 263 } /* Switch */ 264 } /* while (ops) */ 265 } 266 return IRQ_HANDLED; 267 } 268 269 270 static inline void 271 ipi_send(int cpu, enum ipi_message_type op) 272 { 273 struct cpuinfo_parisc *p = &cpu_data[cpu]; 274 unsigned long flags; 275 276 spin_lock_irqsave(&(p->lock),flags); 277 p->pending_ipi |= 1 << op; 278 gsc_writel(IPI_IRQ - CPU_IRQ_BASE, cpu_data[cpu].hpa); 279 spin_unlock_irqrestore(&(p->lock),flags); 280 } 281 282 283 static inline void 284 send_IPI_single(int dest_cpu, enum ipi_message_type op) 285 { 286 if (dest_cpu == NO_PROC_ID) { 287 BUG(); 288 return; 289 } 290 291 ipi_send(dest_cpu, op); 292 } 293 294 static inline void 295 send_IPI_allbutself(enum ipi_message_type op) 296 { 297 int i; 298 299 for (i = 0; i < NR_CPUS; i++) { 300 if (cpu_online(i) && i != smp_processor_id()) 301 send_IPI_single(i, op); 302 } 303 } 304 305 306 inline void 307 smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); } 308 309 static inline void 310 smp_send_start(void) { send_IPI_allbutself(IPI_CPU_START); } 311 312 void 313 smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); } 314 315 316 /** 317 * Run a function on all other CPUs. 318 * <func> The function to run. This must be fast and non-blocking. 319 * <info> An arbitrary pointer to pass to the function. 320 * <retry> If true, keep retrying until ready. 321 * <wait> If true, wait until function has completed on other CPUs. 322 * [RETURNS] 0 on success, else a negative status code. 323 * 324 * Does not return until remote CPUs are nearly ready to execute <func> 325 * or have executed. 326 */ 327 328 int 329 smp_call_function (void (*func) (void *info), void *info, int retry, int wait) 330 { 331 struct smp_call_struct data; 332 unsigned long timeout; 333 static DEFINE_SPINLOCK(lock); 334 int retries = 0; 335 336 if (num_online_cpus() < 2) 337 return 0; 338 339 /* Can deadlock when called with interrupts disabled */ 340 WARN_ON(irqs_disabled()); 341 342 data.func = func; 343 data.info = info; 344 data.wait = wait; 345 atomic_set(&data.unstarted_count, num_online_cpus() - 1); 346 atomic_set(&data.unfinished_count, num_online_cpus() - 1); 347 348 if (retry) { 349 spin_lock (&lock); 350 while (smp_call_function_data != 0) 351 barrier(); 352 } 353 else { 354 spin_lock (&lock); 355 if (smp_call_function_data) { 356 spin_unlock (&lock); 357 return -EBUSY; 358 } 359 } 360 361 smp_call_function_data = &data; 362 spin_unlock (&lock); 363 364 /* Send a message to all other CPUs and wait for them to respond */ 365 send_IPI_allbutself(IPI_CALL_FUNC); 366 367 retry: 368 /* Wait for response */ 369 timeout = jiffies + HZ; 370 while ( (atomic_read (&data.unstarted_count) > 0) && 371 time_before (jiffies, timeout) ) 372 barrier (); 373 374 if (atomic_read (&data.unstarted_count) > 0) { 375 printk(KERN_CRIT "SMP CALL FUNCTION TIMED OUT! (cpu=%d), try %d\n", 376 smp_processor_id(), ++retries); 377 goto retry; 378 } 379 /* We either got one or timed out. Release the lock */ 380 381 mb(); 382 smp_call_function_data = NULL; 383 384 while (wait && atomic_read (&data.unfinished_count) > 0) 385 barrier (); 386 387 return 0; 388 } 389 390 EXPORT_SYMBOL(smp_call_function); 391 392 /* 393 * Flush all other CPU's tlb and then mine. Do this with on_each_cpu() 394 * as we want to ensure all TLB's flushed before proceeding. 395 */ 396 397 extern void flush_tlb_all_local(void); 398 399 void 400 smp_flush_tlb_all(void) 401 { 402 on_each_cpu((void (*)(void *))flush_tlb_all_local, NULL, 1, 1); 403 } 404 405 406 void 407 smp_do_timer(struct pt_regs *regs) 408 { 409 int cpu = smp_processor_id(); 410 struct cpuinfo_parisc *data = &cpu_data[cpu]; 411 412 if (!--data->prof_counter) { 413 data->prof_counter = data->prof_multiplier; 414 update_process_times(user_mode(regs)); 415 } 416 } 417 418 /* 419 * Called by secondaries to update state and initialize CPU registers. 420 */ 421 static void __init 422 smp_cpu_init(int cpunum) 423 { 424 extern int init_per_cpu(int); /* arch/parisc/kernel/setup.c */ 425 extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */ 426 427 /* Set modes and Enable floating point coprocessor */ 428 (void) init_per_cpu(cpunum); 429 430 disable_sr_hashing(); 431 432 mb(); 433 434 /* Well, support 2.4 linux scheme as well. */ 435 if (cpu_test_and_set(cpunum, cpu_online_map)) 436 { 437 extern void machine_halt(void); /* arch/parisc.../process.c */ 438 439 printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum); 440 machine_halt(); 441 } 442 443 /* Initialise the idle task for this CPU */ 444 atomic_inc(&init_mm.mm_count); 445 current->active_mm = &init_mm; 446 if(current->mm) 447 BUG(); 448 enter_lazy_tlb(&init_mm, current); 449 450 init_IRQ(); /* make sure no IRQ's are enabled or pending */ 451 } 452 453 454 /* 455 * Slaves start using C here. Indirectly called from smp_slave_stext. 456 * Do what start_kernel() and main() do for boot strap processor (aka monarch) 457 */ 458 void __init smp_callin(void) 459 { 460 int slave_id = cpu_now_booting; 461 #if 0 462 void *istack; 463 #endif 464 465 smp_cpu_init(slave_id); 466 467 #if 0 /* NOT WORKING YET - see entry.S */ 468 istack = (void *)__get_free_pages(GFP_KERNEL,ISTACK_ORDER); 469 if (istack == NULL) { 470 printk(KERN_CRIT "Failed to allocate interrupt stack for cpu %d\n",slave_id); 471 BUG(); 472 } 473 mtctl(istack,31); 474 #endif 475 476 flush_cache_all_local(); /* start with known state */ 477 flush_tlb_all_local(); 478 479 local_irq_enable(); /* Interrupts have been off until now */ 480 481 cpu_idle(); /* Wait for timer to schedule some work */ 482 483 /* NOTREACHED */ 484 panic("smp_callin() AAAAaaaaahhhh....\n"); 485 } 486 487 /* 488 * Bring one cpu online. 489 */ 490 int __init smp_boot_one_cpu(int cpuid) 491 { 492 struct task_struct *idle; 493 long timeout; 494 495 /* 496 * Create an idle task for this CPU. Note the address wed* give 497 * to kernel_thread is irrelevant -- it's going to start 498 * where OS_BOOT_RENDEVZ vector in SAL says to start. But 499 * this gets all the other task-y sort of data structures set 500 * up like we wish. We need to pull the just created idle task 501 * off the run queue and stuff it into the init_tasks[] array. 502 * Sheesh . . . 503 */ 504 505 idle = fork_idle(cpuid); 506 if (IS_ERR(idle)) 507 panic("SMP: fork failed for CPU:%d", cpuid); 508 509 idle->thread_info->cpu = cpuid; 510 511 /* Let _start know what logical CPU we're booting 512 ** (offset into init_tasks[],cpu_data[]) 513 */ 514 cpu_now_booting = cpuid; 515 516 /* 517 ** boot strap code needs to know the task address since 518 ** it also contains the process stack. 519 */ 520 smp_init_current_idle_task = idle ; 521 mb(); 522 523 printk("Releasing cpu %d now, hpa=%lx\n", cpuid, cpu_data[cpuid].hpa); 524 525 /* 526 ** This gets PDC to release the CPU from a very tight loop. 527 ** 528 ** From the PA-RISC 2.0 Firmware Architecture Reference Specification: 529 ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which 530 ** is executed after receiving the rendezvous signal (an interrupt to 531 ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the 532 ** contents of memory are valid." 533 */ 534 gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, cpu_data[cpuid].hpa); 535 mb(); 536 537 /* 538 * OK, wait a bit for that CPU to finish staggering about. 539 * Slave will set a bit when it reaches smp_cpu_init(). 540 * Once the "monarch CPU" sees the bit change, it can move on. 541 */ 542 for (timeout = 0; timeout < 10000; timeout++) { 543 if(cpu_online(cpuid)) { 544 /* Which implies Slave has started up */ 545 cpu_now_booting = 0; 546 smp_init_current_idle_task = NULL; 547 goto alive ; 548 } 549 udelay(100); 550 barrier(); 551 } 552 553 put_task_struct(idle); 554 idle = NULL; 555 556 printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid); 557 return -1; 558 559 alive: 560 /* Remember the Slave data */ 561 #if (kDEBUG>=100) 562 printk(KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n", 563 cpuid, timeout * 100); 564 #endif /* kDEBUG */ 565 #ifdef ENTRY_SYS_CPUS 566 cpu_data[cpuid].state = STATE_RUNNING; 567 #endif 568 return 0; 569 } 570 571 void __devinit smp_prepare_boot_cpu(void) 572 { 573 int bootstrap_processor=cpu_data[0].cpuid; /* CPU ID of BSP */ 574 575 #ifdef ENTRY_SYS_CPUS 576 cpu_data[0].state = STATE_RUNNING; 577 #endif 578 579 /* Setup BSP mappings */ 580 printk("SMP: bootstrap CPU ID is %d\n",bootstrap_processor); 581 582 cpu_set(bootstrap_processor, cpu_online_map); 583 cpu_set(bootstrap_processor, cpu_present_map); 584 } 585 586 587 588 /* 589 ** inventory.c:do_inventory() hasn't yet been run and thus we 590 ** don't 'discover' the additional CPU's until later. 591 */ 592 void __init smp_prepare_cpus(unsigned int max_cpus) 593 { 594 cpus_clear(cpu_present_map); 595 cpu_set(0, cpu_present_map); 596 597 parisc_max_cpus = max_cpus; 598 if (!max_cpus) 599 printk(KERN_INFO "SMP mode deactivated.\n"); 600 } 601 602 603 void smp_cpus_done(unsigned int cpu_max) 604 { 605 return; 606 } 607 608 609 int __devinit __cpu_up(unsigned int cpu) 610 { 611 if (cpu != 0 && cpu < parisc_max_cpus) 612 smp_boot_one_cpu(cpu); 613 614 return cpu_online(cpu) ? 0 : -ENOSYS; 615 } 616 617 618 619 #ifdef ENTRY_SYS_CPUS 620 /* Code goes along with: 621 ** entry.s: ENTRY_NAME(sys_cpus) / * 215, for cpu stat * / 622 */ 623 int sys_cpus(int argc, char **argv) 624 { 625 int i,j=0; 626 extern int current_pid(int cpu); 627 628 if( argc > 2 ) { 629 printk("sys_cpus:Only one argument supported\n"); 630 return (-1); 631 } 632 if ( argc == 1 ){ 633 634 #ifdef DUMP_MORE_STATE 635 for(i=0; i<NR_CPUS; i++) { 636 int cpus_per_line = 4; 637 if(cpu_online(i)) { 638 if (j++ % cpus_per_line) 639 printk(" %3d",i); 640 else 641 printk("\n %3d",i); 642 } 643 } 644 printk("\n"); 645 #else 646 printk("\n 0\n"); 647 #endif 648 } else if((argc==2) && !(strcmp(argv[1],"-l"))) { 649 printk("\nCPUSTATE TASK CPUNUM CPUID HARDCPU(HPA)\n"); 650 #ifdef DUMP_MORE_STATE 651 for(i=0;i<NR_CPUS;i++) { 652 if (!cpu_online(i)) 653 continue; 654 if (cpu_data[i].cpuid != NO_PROC_ID) { 655 switch(cpu_data[i].state) { 656 case STATE_RENDEZVOUS: 657 printk("RENDEZVS "); 658 break; 659 case STATE_RUNNING: 660 printk((current_pid(i)!=0) ? "RUNNING " : "IDLING "); 661 break; 662 case STATE_STOPPED: 663 printk("STOPPED "); 664 break; 665 case STATE_HALTED: 666 printk("HALTED "); 667 break; 668 default: 669 printk("%08x?", cpu_data[i].state); 670 break; 671 } 672 if(cpu_online(i)) { 673 printk(" %4d",current_pid(i)); 674 } 675 printk(" %6d",cpu_number_map(i)); 676 printk(" %5d",i); 677 printk(" 0x%lx\n",cpu_data[i].hpa); 678 } 679 } 680 #else 681 printk("\n%s %4d 0 0 --------", 682 (current->pid)?"RUNNING ": "IDLING ",current->pid); 683 #endif 684 } else if ((argc==2) && !(strcmp(argv[1],"-s"))) { 685 #ifdef DUMP_MORE_STATE 686 printk("\nCPUSTATE CPUID\n"); 687 for (i=0;i<NR_CPUS;i++) { 688 if (!cpu_online(i)) 689 continue; 690 if (cpu_data[i].cpuid != NO_PROC_ID) { 691 switch(cpu_data[i].state) { 692 case STATE_RENDEZVOUS: 693 printk("RENDEZVS");break; 694 case STATE_RUNNING: 695 printk((current_pid(i)!=0) ? "RUNNING " : "IDLING"); 696 break; 697 case STATE_STOPPED: 698 printk("STOPPED ");break; 699 case STATE_HALTED: 700 printk("HALTED ");break; 701 default: 702 } 703 printk(" %5d\n",i); 704 } 705 } 706 #else 707 printk("\n%s CPU0",(current->pid==0)?"RUNNING ":"IDLING "); 708 #endif 709 } else { 710 printk("sys_cpus:Unknown request\n"); 711 return (-1); 712 } 713 return 0; 714 } 715 #endif /* ENTRY_SYS_CPUS */ 716 717 #ifdef CONFIG_PROC_FS 718 int __init 719 setup_profiling_timer(unsigned int multiplier) 720 { 721 return -EINVAL; 722 } 723 #endif 724