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