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, struct pt_regs *regs) 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 } /* while (ops) */ 266 } 267 return IRQ_HANDLED; 268 } 269 270 271 static inline void 272 ipi_send(int cpu, enum ipi_message_type op) 273 { 274 struct cpuinfo_parisc *p = &cpu_data[cpu]; 275 unsigned long flags; 276 277 spin_lock_irqsave(&(p->lock),flags); 278 p->pending_ipi |= 1 << op; 279 gsc_writel(IPI_IRQ - CPU_IRQ_BASE, cpu_data[cpu].hpa); 280 spin_unlock_irqrestore(&(p->lock),flags); 281 } 282 283 284 static inline void 285 send_IPI_single(int dest_cpu, enum ipi_message_type op) 286 { 287 if (dest_cpu == NO_PROC_ID) { 288 BUG(); 289 return; 290 } 291 292 ipi_send(dest_cpu, op); 293 } 294 295 static inline void 296 send_IPI_allbutself(enum ipi_message_type op) 297 { 298 int i; 299 300 for_each_online_cpu(i) { 301 if (i != smp_processor_id()) 302 send_IPI_single(i, op); 303 } 304 } 305 306 307 inline void 308 smp_send_stop(void) { send_IPI_allbutself(IPI_CPU_STOP); } 309 310 static inline void 311 smp_send_start(void) { send_IPI_allbutself(IPI_CPU_START); } 312 313 void 314 smp_send_reschedule(int cpu) { send_IPI_single(cpu, IPI_RESCHEDULE); } 315 316 void 317 smp_send_all_nop(void) 318 { 319 send_IPI_allbutself(IPI_NOP); 320 } 321 322 323 /** 324 * Run a function on all other CPUs. 325 * <func> The function to run. This must be fast and non-blocking. 326 * <info> An arbitrary pointer to pass to the function. 327 * <retry> If true, keep retrying until ready. 328 * <wait> If true, wait until function has completed on other CPUs. 329 * [RETURNS] 0 on success, else a negative status code. 330 * 331 * Does not return until remote CPUs are nearly ready to execute <func> 332 * or have executed. 333 */ 334 335 int 336 smp_call_function (void (*func) (void *info), void *info, int retry, int wait) 337 { 338 struct smp_call_struct data; 339 unsigned long timeout; 340 static DEFINE_SPINLOCK(lock); 341 int retries = 0; 342 343 if (num_online_cpus() < 2) 344 return 0; 345 346 /* Can deadlock when called with interrupts disabled */ 347 WARN_ON(irqs_disabled()); 348 349 /* can also deadlock if IPIs are disabled */ 350 WARN_ON((get_eiem() & (1UL<<(CPU_IRQ_MAX - IPI_IRQ))) == 0); 351 352 353 data.func = func; 354 data.info = info; 355 data.wait = wait; 356 atomic_set(&data.unstarted_count, num_online_cpus() - 1); 357 atomic_set(&data.unfinished_count, num_online_cpus() - 1); 358 359 if (retry) { 360 spin_lock (&lock); 361 while (smp_call_function_data != 0) 362 barrier(); 363 } 364 else { 365 spin_lock (&lock); 366 if (smp_call_function_data) { 367 spin_unlock (&lock); 368 return -EBUSY; 369 } 370 } 371 372 smp_call_function_data = &data; 373 spin_unlock (&lock); 374 375 /* Send a message to all other CPUs and wait for them to respond */ 376 send_IPI_allbutself(IPI_CALL_FUNC); 377 378 retry: 379 /* Wait for response */ 380 timeout = jiffies + HZ; 381 while ( (atomic_read (&data.unstarted_count) > 0) && 382 time_before (jiffies, timeout) ) 383 barrier (); 384 385 if (atomic_read (&data.unstarted_count) > 0) { 386 printk(KERN_CRIT "SMP CALL FUNCTION TIMED OUT! (cpu=%d), try %d\n", 387 smp_processor_id(), ++retries); 388 goto retry; 389 } 390 /* We either got one or timed out. Release the lock */ 391 392 mb(); 393 smp_call_function_data = NULL; 394 395 while (wait && atomic_read (&data.unfinished_count) > 0) 396 barrier (); 397 398 return 0; 399 } 400 401 EXPORT_SYMBOL(smp_call_function); 402 403 /* 404 * Flush all other CPU's tlb and then mine. Do this with on_each_cpu() 405 * as we want to ensure all TLB's flushed before proceeding. 406 */ 407 408 void 409 smp_flush_tlb_all(void) 410 { 411 on_each_cpu(flush_tlb_all_local, NULL, 1, 1); 412 } 413 414 415 void 416 smp_do_timer(struct pt_regs *regs) 417 { 418 int cpu = smp_processor_id(); 419 struct cpuinfo_parisc *data = &cpu_data[cpu]; 420 421 if (!--data->prof_counter) { 422 data->prof_counter = data->prof_multiplier; 423 update_process_times(user_mode(regs)); 424 } 425 } 426 427 /* 428 * Called by secondaries to update state and initialize CPU registers. 429 */ 430 static void __init 431 smp_cpu_init(int cpunum) 432 { 433 extern int init_per_cpu(int); /* arch/parisc/kernel/setup.c */ 434 extern void init_IRQ(void); /* arch/parisc/kernel/irq.c */ 435 436 /* Set modes and Enable floating point coprocessor */ 437 (void) init_per_cpu(cpunum); 438 439 disable_sr_hashing(); 440 441 mb(); 442 443 /* Well, support 2.4 linux scheme as well. */ 444 if (cpu_test_and_set(cpunum, cpu_online_map)) 445 { 446 extern void machine_halt(void); /* arch/parisc.../process.c */ 447 448 printk(KERN_CRIT "CPU#%d already initialized!\n", cpunum); 449 machine_halt(); 450 } 451 452 /* Initialise the idle task for this CPU */ 453 atomic_inc(&init_mm.mm_count); 454 current->active_mm = &init_mm; 455 if(current->mm) 456 BUG(); 457 enter_lazy_tlb(&init_mm, current); 458 459 init_IRQ(); /* make sure no IRQ's are enabled or pending */ 460 } 461 462 463 /* 464 * Slaves start using C here. Indirectly called from smp_slave_stext. 465 * Do what start_kernel() and main() do for boot strap processor (aka monarch) 466 */ 467 void __init smp_callin(void) 468 { 469 int slave_id = cpu_now_booting; 470 #if 0 471 void *istack; 472 #endif 473 474 smp_cpu_init(slave_id); 475 preempt_disable(); 476 477 #if 0 /* NOT WORKING YET - see entry.S */ 478 istack = (void *)__get_free_pages(GFP_KERNEL,ISTACK_ORDER); 479 if (istack == NULL) { 480 printk(KERN_CRIT "Failed to allocate interrupt stack for cpu %d\n",slave_id); 481 BUG(); 482 } 483 mtctl(istack,31); 484 #endif 485 486 flush_cache_all_local(); /* start with known state */ 487 flush_tlb_all_local(NULL); 488 489 local_irq_enable(); /* Interrupts have been off until now */ 490 491 cpu_idle(); /* Wait for timer to schedule some work */ 492 493 /* NOTREACHED */ 494 panic("smp_callin() AAAAaaaaahhhh....\n"); 495 } 496 497 /* 498 * Bring one cpu online. 499 */ 500 int __init smp_boot_one_cpu(int cpuid) 501 { 502 struct task_struct *idle; 503 long timeout; 504 505 /* 506 * Create an idle task for this CPU. Note the address wed* give 507 * to kernel_thread is irrelevant -- it's going to start 508 * where OS_BOOT_RENDEVZ vector in SAL says to start. But 509 * this gets all the other task-y sort of data structures set 510 * up like we wish. We need to pull the just created idle task 511 * off the run queue and stuff it into the init_tasks[] array. 512 * Sheesh . . . 513 */ 514 515 idle = fork_idle(cpuid); 516 if (IS_ERR(idle)) 517 panic("SMP: fork failed for CPU:%d", cpuid); 518 519 task_thread_info(idle)->cpu = cpuid; 520 521 /* Let _start know what logical CPU we're booting 522 ** (offset into init_tasks[],cpu_data[]) 523 */ 524 cpu_now_booting = cpuid; 525 526 /* 527 ** boot strap code needs to know the task address since 528 ** it also contains the process stack. 529 */ 530 smp_init_current_idle_task = idle ; 531 mb(); 532 533 printk("Releasing cpu %d now, hpa=%lx\n", cpuid, cpu_data[cpuid].hpa); 534 535 /* 536 ** This gets PDC to release the CPU from a very tight loop. 537 ** 538 ** From the PA-RISC 2.0 Firmware Architecture Reference Specification: 539 ** "The MEM_RENDEZ vector specifies the location of OS_RENDEZ which 540 ** is executed after receiving the rendezvous signal (an interrupt to 541 ** EIR{0}). MEM_RENDEZ is valid only when it is nonzero and the 542 ** contents of memory are valid." 543 */ 544 gsc_writel(TIMER_IRQ - CPU_IRQ_BASE, cpu_data[cpuid].hpa); 545 mb(); 546 547 /* 548 * OK, wait a bit for that CPU to finish staggering about. 549 * Slave will set a bit when it reaches smp_cpu_init(). 550 * Once the "monarch CPU" sees the bit change, it can move on. 551 */ 552 for (timeout = 0; timeout < 10000; timeout++) { 553 if(cpu_online(cpuid)) { 554 /* Which implies Slave has started up */ 555 cpu_now_booting = 0; 556 smp_init_current_idle_task = NULL; 557 goto alive ; 558 } 559 udelay(100); 560 barrier(); 561 } 562 563 put_task_struct(idle); 564 idle = NULL; 565 566 printk(KERN_CRIT "SMP: CPU:%d is stuck.\n", cpuid); 567 return -1; 568 569 alive: 570 /* Remember the Slave data */ 571 #if (kDEBUG>=100) 572 printk(KERN_DEBUG "SMP: CPU:%d came alive after %ld _us\n", 573 cpuid, timeout * 100); 574 #endif /* kDEBUG */ 575 #ifdef ENTRY_SYS_CPUS 576 cpu_data[cpuid].state = STATE_RUNNING; 577 #endif 578 return 0; 579 } 580 581 void __devinit smp_prepare_boot_cpu(void) 582 { 583 int bootstrap_processor=cpu_data[0].cpuid; /* CPU ID of BSP */ 584 585 #ifdef ENTRY_SYS_CPUS 586 cpu_data[0].state = STATE_RUNNING; 587 #endif 588 589 /* Setup BSP mappings */ 590 printk("SMP: bootstrap CPU ID is %d\n",bootstrap_processor); 591 592 cpu_set(bootstrap_processor, cpu_online_map); 593 cpu_set(bootstrap_processor, cpu_present_map); 594 } 595 596 597 598 /* 599 ** inventory.c:do_inventory() hasn't yet been run and thus we 600 ** don't 'discover' the additional CPU's until later. 601 */ 602 void __init smp_prepare_cpus(unsigned int max_cpus) 603 { 604 cpus_clear(cpu_present_map); 605 cpu_set(0, cpu_present_map); 606 607 parisc_max_cpus = max_cpus; 608 if (!max_cpus) 609 printk(KERN_INFO "SMP mode deactivated.\n"); 610 } 611 612 613 void smp_cpus_done(unsigned int cpu_max) 614 { 615 return; 616 } 617 618 619 int __devinit __cpu_up(unsigned int cpu) 620 { 621 if (cpu != 0 && cpu < parisc_max_cpus) 622 smp_boot_one_cpu(cpu); 623 624 return cpu_online(cpu) ? 0 : -ENOSYS; 625 } 626 627 628 629 #ifdef ENTRY_SYS_CPUS 630 /* Code goes along with: 631 ** entry.s: ENTRY_NAME(sys_cpus) / * 215, for cpu stat * / 632 */ 633 int sys_cpus(int argc, char **argv) 634 { 635 int i,j=0; 636 extern int current_pid(int cpu); 637 638 if( argc > 2 ) { 639 printk("sys_cpus:Only one argument supported\n"); 640 return (-1); 641 } 642 if ( argc == 1 ){ 643 644 #ifdef DUMP_MORE_STATE 645 for_each_online_cpu(i) { 646 int cpus_per_line = 4; 647 648 if (j++ % cpus_per_line) 649 printk(" %3d",i); 650 else 651 printk("\n %3d",i); 652 } 653 printk("\n"); 654 #else 655 printk("\n 0\n"); 656 #endif 657 } else if((argc==2) && !(strcmp(argv[1],"-l"))) { 658 printk("\nCPUSTATE TASK CPUNUM CPUID HARDCPU(HPA)\n"); 659 #ifdef DUMP_MORE_STATE 660 for_each_online_cpu(i) { 661 if (cpu_data[i].cpuid != NO_PROC_ID) { 662 switch(cpu_data[i].state) { 663 case STATE_RENDEZVOUS: 664 printk("RENDEZVS "); 665 break; 666 case STATE_RUNNING: 667 printk((current_pid(i)!=0) ? "RUNNING " : "IDLING "); 668 break; 669 case STATE_STOPPED: 670 printk("STOPPED "); 671 break; 672 case STATE_HALTED: 673 printk("HALTED "); 674 break; 675 default: 676 printk("%08x?", cpu_data[i].state); 677 break; 678 } 679 if(cpu_online(i)) { 680 printk(" %4d",current_pid(i)); 681 } 682 printk(" %6d",cpu_number_map(i)); 683 printk(" %5d",i); 684 printk(" 0x%lx\n",cpu_data[i].hpa); 685 } 686 } 687 #else 688 printk("\n%s %4d 0 0 --------", 689 (current->pid)?"RUNNING ": "IDLING ",current->pid); 690 #endif 691 } else if ((argc==2) && !(strcmp(argv[1],"-s"))) { 692 #ifdef DUMP_MORE_STATE 693 printk("\nCPUSTATE CPUID\n"); 694 for_each_online_cpu(i) { 695 if (cpu_data[i].cpuid != NO_PROC_ID) { 696 switch(cpu_data[i].state) { 697 case STATE_RENDEZVOUS: 698 printk("RENDEZVS");break; 699 case STATE_RUNNING: 700 printk((current_pid(i)!=0) ? "RUNNING " : "IDLING"); 701 break; 702 case STATE_STOPPED: 703 printk("STOPPED ");break; 704 case STATE_HALTED: 705 printk("HALTED ");break; 706 default: 707 } 708 printk(" %5d\n",i); 709 } 710 } 711 #else 712 printk("\n%s CPU0",(current->pid==0)?"RUNNING ":"IDLING "); 713 #endif 714 } else { 715 printk("sys_cpus:Unknown request\n"); 716 return (-1); 717 } 718 return 0; 719 } 720 #endif /* ENTRY_SYS_CPUS */ 721 722 #ifdef CONFIG_PROC_FS 723 int __init 724 setup_profiling_timer(unsigned int multiplier) 725 { 726 return -EINVAL; 727 } 728 #endif 729