Linux Kernel  3.7.1
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
smpboot.c
Go to the documentation of this file.
1 /*
2  * linux/arch/m32r/kernel/smpboot.c
3  * orig : i386 2.4.10
4  *
5  * M32R SMP booting functions
6  *
7  * Copyright (c) 2001, 2002, 2003 Hitoshi Yamamoto
8  *
9  * Taken from i386 version.
10  * (c) 1995 Alan Cox, Building #3 <[email protected]>
11  * (c) 1998, 1999, 2000 Ingo Molnar <[email protected]>
12  *
13  * Much of the core SMP work is based on previous work by Thomas Radke, to
14  * whom a great many thanks are extended.
15  *
16  * Thanks to Intel for making available several different Pentium,
17  * Pentium Pro and Pentium-II/Xeon MP machines.
18  * Original development of Linux SMP code supported by Caldera.
19  *
20  * This code is released under the GNU General Public License version 2 or
21  * later.
22  *
23  * Fixes
24  * Felix Koop : NR_CPUS used properly
25  * Jose Renau : Handle single CPU case.
26  * Alan Cox : By repeated request
27  * 8) - Total BogoMIP report.
28  * Greg Wright : Fix for kernel stacks panic.
29  * Erich Boleyn : MP v1.4 and additional changes.
30  * Matthias Sattler : Changes for 2.1 kernel map.
31  * Michel Lespinasse : Changes for 2.1 kernel map.
32  * Michael Chastain : Change trampoline.S to gnu as.
33  * Alan Cox : Dumb bug: 'B' step PPro's are fine
34  * Ingo Molnar : Added APIC timers, based on code
35  * from Jose Renau
36  * Ingo Molnar : various cleanups and rewrites
37  * Tigran Aivazian : fixed "0.00 in /proc/uptime on SMP" bug.
38  * Maciej W. Rozycki : Bits for genuine 82489DX APICs
39  * Martin J. Bligh : Added support for multi-quad systems
40  */
41 
42 #include <linux/module.h>
43 #include <linux/cpu.h>
44 #include <linux/init.h>
45 #include <linux/kernel.h>
46 #include <linux/mm.h>
47 #include <linux/sched.h>
48 #include <linux/err.h>
49 #include <linux/irq.h>
50 #include <linux/bootmem.h>
51 #include <linux/delay.h>
52 
53 #include <asm/io.h>
54 #include <asm/pgalloc.h>
55 #include <asm/tlbflush.h>
56 
57 #define DEBUG_SMP
58 #ifdef DEBUG_SMP
59 #define Dprintk(x...) printk(x)
60 #else
61 #define Dprintk(x...)
62 #endif
63 
65 
66 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
67 /* Data structures and variables */
68 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
69 
70 /* Processor that is doing the boot up */
71 static unsigned int bsp_phys_id = -1;
72 
73 /* Bitmask of physically existing CPUs */
75 
78 static cpumask_t cpu_callin_map;
80 EXPORT_SYMBOL(cpu_callout_map);
81 
82 /* Per CPU bogomips and other parameters */
84 
85 static int cpucount;
86 static cpumask_t smp_commenced_mask;
87 
88 extern struct {
89  void * spi;
90  unsigned short ss;
91 } stack_start;
92 
93 /* which physical physical ID maps to which logical CPU number */
94 static volatile int physid_2_cpu[NR_CPUS];
95 #define physid_to_cpu(physid) physid_2_cpu[physid]
96 
97 /* which logical CPU number maps to which physical ID */
98 volatile int cpu_2_physid[NR_CPUS];
99 
100 DEFINE_PER_CPU(int, prof_multiplier) = 1;
101 DEFINE_PER_CPU(int, prof_old_multiplier) = 1;
102 DEFINE_PER_CPU(int, prof_counter) = 1;
103 
105 
106 static unsigned int calibration_result;
107 
108 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
109 /* Function Prototypes */
110 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
111 
112 static void init_ipi_lock(void);
113 static void do_boot_cpu(int);
114 
115 int start_secondary(void *);
116 static void smp_callin(void);
117 static void smp_online(void);
118 
119 static void show_mp_info(int);
120 static void smp_store_cpu_info(int);
121 static void show_cpu_info(int);
122 int setup_profiling_timer(unsigned int);
123 static void init_cpu_to_physid(void);
124 static void map_cpu_to_physid(int, int);
125 static void unmap_cpu_to_physid(int, int);
126 
127 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
128 /* Boot up APs Routines : BSP */
129 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
131 {
132  bsp_phys_id = hard_smp_processor_id();
133  physid_set(bsp_phys_id, phys_cpu_present_map);
134  set_cpu_online(0, true); /* BSP's cpu_id == 0 */
135  cpumask_set_cpu(0, &cpu_callout_map);
136  cpumask_set_cpu(0, &cpu_callin_map);
137 
138  /*
139  * Initialize the logical to physical CPU number mapping
140  */
141  init_cpu_to_physid();
142  map_cpu_to_physid(0, bsp_phys_id);
143  current_thread_info()->cpu = 0;
144 }
145 
146 /*==========================================================================*
147  * Name: smp_prepare_cpus (old smp_boot_cpus)
148  *
149  * Description: This routine boot up APs.
150  *
151  * Born on Date: 2002.02.05
152  *
153  * Arguments: NONE
154  *
155  * Returns: void (cannot fail)
156  *
157  * Modification log:
158  * Date Who Description
159  * ---------- --- --------------------------------------------------------
160  * 2003-06-24 hy modify for linux-2.5.69
161  *
162  *==========================================================================*/
163 void __init smp_prepare_cpus(unsigned int max_cpus)
164 {
165  int phys_id;
166  unsigned long nr_cpu;
167 
169  if (nr_cpu > NR_CPUS) {
170  printk(KERN_INFO "NUM_OF_CPUS reg. value [%ld] > NR_CPU [%d]",
171  nr_cpu, NR_CPUS);
172  goto smp_done;
173  }
174  for (phys_id = 0 ; phys_id < nr_cpu ; phys_id++)
175  physid_set(phys_id, phys_cpu_present_map);
176 #ifndef CONFIG_HOTPLUG_CPU
178 #endif
179 
180  show_mp_info(nr_cpu);
181 
182  init_ipi_lock();
183 
184  /*
185  * Setup boot CPU information
186  */
187  smp_store_cpu_info(0); /* Final full version of the data */
188 
189  /*
190  * If SMP should be disabled, then really disable it!
191  */
192  if (!max_cpus) {
193  printk(KERN_INFO "SMP mode deactivated by commandline.\n");
194  goto smp_done;
195  }
196 
197  /*
198  * Now scan the CPU present map and fire up the other CPUs.
199  */
200  Dprintk("CPU present map : %lx\n", physids_coerce(phys_cpu_present_map));
201 
202  for (phys_id = 0 ; phys_id < NR_CPUS ; phys_id++) {
203  /*
204  * Don't even attempt to start the boot CPU!
205  */
206  if (phys_id == bsp_phys_id)
207  continue;
208 
209  if (!physid_isset(phys_id, phys_cpu_present_map))
210  continue;
211 
212  if (max_cpus <= cpucount + 1)
213  continue;
214 
215  do_boot_cpu(phys_id);
216 
217  /*
218  * Make sure we unmap all failed CPUs
219  */
220  if (physid_to_cpu(phys_id) == -1) {
221  physid_clear(phys_id, phys_cpu_present_map);
222  printk("phys CPU#%d not responding - " \
223  "cannot use it.\n", phys_id);
224  }
225  }
226 
227 smp_done:
228  Dprintk("Boot done.\n");
229 }
230 
231 /*
232  * init_ipi_lock : Initialize IPI locks.
233  */
234 static void __init init_ipi_lock(void)
235 {
236  int ipi;
237 
238  for (ipi = 0 ; ipi < NR_IPIS ; ipi++)
239  spin_lock_init(&ipi_lock[ipi]);
240 }
241 
242 /*==========================================================================*
243  * Name: do_boot_cpu
244  *
245  * Description: This routine boot up one AP.
246  *
247  * Born on Date: 2002.02.05
248  *
249  * Arguments: phys_id - Target CPU physical ID
250  *
251  * Returns: void (cannot fail)
252  *
253  * Modification log:
254  * Date Who Description
255  * ---------- --- --------------------------------------------------------
256  * 2003-06-24 hy modify for linux-2.5.69
257  *
258  *==========================================================================*/
259 static void __init do_boot_cpu(int phys_id)
260 {
261  struct task_struct *idle;
262  unsigned long send_status, boot_status;
263  int timeout, cpu_id;
264 
265  cpu_id = ++cpucount;
266 
267  /*
268  * We can't use kernel_thread since we must avoid to
269  * reschedule the child.
270  */
271  idle = fork_idle(cpu_id);
272  if (IS_ERR(idle))
273  panic("failed fork for CPU#%d.", cpu_id);
274 
275  idle->thread.lr = (unsigned long)start_secondary;
276 
277  map_cpu_to_physid(cpu_id, phys_id);
278 
279  /* So we see what's up */
280  printk("Booting processor %d/%d\n", phys_id, cpu_id);
281  stack_start.spi = (void *)idle->thread.sp;
282  task_thread_info(idle)->cpu = cpu_id;
283 
284  /*
285  * Send Startup IPI
286  * 1.IPI received by CPU#(phys_id).
287  * 2.CPU#(phys_id) enter startup_AP (arch/m32r/kernel/head.S)
288  * 3.CPU#(phys_id) enter start_secondary()
289  */
290  send_status = 0;
291  boot_status = 0;
292 
293  cpumask_set_cpu(phys_id, &cpu_bootout_map);
294 
295  /* Send Startup IPI */
296  send_IPI_mask_phys(cpumask_of(phys_id), CPU_BOOT_IPI, 0);
297 
298  Dprintk("Waiting for send to finish...\n");
299  timeout = 0;
300 
301  /* Wait 100[ms] */
302  do {
303  Dprintk("+");
304  udelay(1000);
305  send_status = !cpumask_test_cpu(phys_id, &cpu_bootin_map);
306  } while (send_status && (timeout++ < 100));
307 
308  Dprintk("After Startup.\n");
309 
310  if (!send_status) {
311  /*
312  * allow APs to start initializing.
313  */
314  Dprintk("Before Callout %d.\n", cpu_id);
315  cpumask_set_cpu(cpu_id, &cpu_callout_map);
316  Dprintk("After Callout %d.\n", cpu_id);
317 
318  /*
319  * Wait 5s total for a response
320  */
321  for (timeout = 0; timeout < 5000; timeout++) {
322  if (cpumask_test_cpu(cpu_id, &cpu_callin_map))
323  break; /* It has booted */
324  udelay(1000);
325  }
326 
327  if (cpumask_test_cpu(cpu_id, &cpu_callin_map)) {
328  /* number CPUs logically, starting from 1 (BSP is 0) */
329  Dprintk("OK.\n");
330  } else {
331  boot_status = 1;
332  printk("Not responding.\n");
333  }
334  } else
335  printk("IPI never delivered???\n");
336 
337  if (send_status || boot_status) {
338  unmap_cpu_to_physid(cpu_id, phys_id);
339  cpumask_clear_cpu(cpu_id, &cpu_callout_map);
340  cpumask_clear_cpu(cpu_id, &cpu_callin_map);
341  cpumask_clear_cpu(cpu_id, &cpu_initialized);
342  cpucount--;
343  }
344 }
345 
346 int __cpuinit __cpu_up(unsigned int cpu_id, struct task_struct *tidle)
347 {
348  int timeout;
349 
350  cpumask_set_cpu(cpu_id, &smp_commenced_mask);
351 
352  /*
353  * Wait 5s total for a response
354  */
355  for (timeout = 0; timeout < 5000; timeout++) {
356  if (cpu_online(cpu_id))
357  break;
358  udelay(1000);
359  }
360  if (!cpu_online(cpu_id))
361  BUG();
362 
363  return 0;
364 }
365 
366 void __init smp_cpus_done(unsigned int max_cpus)
367 {
368  int cpu_id, timeout;
369  unsigned long bogosum = 0;
370 
371  for (timeout = 0; timeout < 5000; timeout++) {
372  if (cpumask_equal(&cpu_callin_map, cpu_online_mask))
373  break;
374  udelay(1000);
375  }
376  if (!cpumask_equal(&cpu_callin_map, cpu_online_mask))
377  BUG();
378 
379  for (cpu_id = 0 ; cpu_id < num_online_cpus() ; cpu_id++)
380  show_cpu_info(cpu_id);
381 
382  /*
383  * Allow the user to impress friends.
384  */
385  Dprintk("Before bogomips.\n");
386  if (cpucount) {
388  bogosum += cpu_data[cpu_id].loops_per_jiffy;
389 
390  printk(KERN_INFO "Total of %d processors activated " \
391  "(%lu.%02lu BogoMIPS).\n", cpucount + 1,
392  bogosum / (500000 / HZ),
393  (bogosum / (5000 / HZ)) % 100);
394  Dprintk("Before bogocount - setting activated=1.\n");
395  }
396 }
397 
398 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
399 /* Activate a secondary processor Routines */
400 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
401 
402 /*==========================================================================*
403  * Name: start_secondary
404  *
405  * Description: This routine activate a secondary processor.
406  *
407  * Born on Date: 2002.02.05
408  *
409  * Arguments: *unused - currently unused.
410  *
411  * Returns: void (cannot fail)
412  *
413  * Modification log:
414  * Date Who Description
415  * ---------- --- --------------------------------------------------------
416  * 2003-06-24 hy modify for linux-2.5.69
417  *
418  *==========================================================================*/
419 int __init start_secondary(void *unused)
420 {
421  cpu_init();
422  preempt_disable();
423  smp_callin();
424  while (!cpumask_test_cpu(smp_processor_id(), &smp_commenced_mask))
425  cpu_relax();
426 
427  smp_online();
428 
429  /*
430  * low-memory mappings have been cleared, flush them from
431  * the local TLBs too.
432  */
434 
435  cpu_idle();
436  return 0;
437 }
438 
439 /*==========================================================================*
440  * Name: smp_callin
441  *
442  * Description: This routine activate a secondary processor.
443  *
444  * Born on Date: 2002.02.05
445  *
446  * Arguments: NONE
447  *
448  * Returns: void (cannot fail)
449  *
450  * Modification log:
451  * Date Who Description
452  * ---------- --- --------------------------------------------------------
453  * 2003-06-24 hy modify for linux-2.5.69
454  *
455  *==========================================================================*/
456 static void __init smp_callin(void)
457 {
458  int phys_id = hard_smp_processor_id();
459  int cpu_id = smp_processor_id();
460  unsigned long timeout;
461 
462  if (cpumask_test_cpu(cpu_id, &cpu_callin_map)) {
463  printk("huh, phys CPU#%d, CPU#%d already present??\n",
464  phys_id, cpu_id);
465  BUG();
466  }
467  Dprintk("CPU#%d (phys ID: %d) waiting for CALLOUT\n", cpu_id, phys_id);
468 
469  /* Waiting 2s total for startup (udelay is not yet working) */
470  timeout = jiffies + (2 * HZ);
471  while (time_before(jiffies, timeout)) {
472  /* Has the boot CPU finished it's STARTUP sequence ? */
473  if (cpumask_test_cpu(cpu_id, &cpu_callout_map))
474  break;
475  cpu_relax();
476  }
477 
478  if (!time_before(jiffies, timeout)) {
479  printk("BUG: CPU#%d started up but did not get a callout!\n",
480  cpu_id);
481  BUG();
482  }
483 
484  /* Allow the master to continue. */
485  cpumask_set_cpu(cpu_id, &cpu_callin_map);
486 }
487 
488 static void __init smp_online(void)
489 {
490  int cpu_id = smp_processor_id();
491 
492  notify_cpu_starting(cpu_id);
493 
495 
496  /* Get our bogomips. */
497  calibrate_delay();
498 
499  /* Save our processor parameters */
500  smp_store_cpu_info(cpu_id);
501 
502  set_cpu_online(cpu_id, true);
503 }
504 
505 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
506 /* Boot up CPUs common Routines */
507 /*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*=*/
508 static void __init show_mp_info(int nr_cpu)
509 {
510  int i;
511  char cpu_model0[17], cpu_model1[17], cpu_ver[9];
512 
513  strncpy(cpu_model0, (char *)M32R_FPGA_CPU_NAME_ADDR, 16);
514  strncpy(cpu_model1, (char *)M32R_FPGA_MODEL_ID_ADDR, 16);
515  strncpy(cpu_ver, (char *)M32R_FPGA_VERSION_ADDR, 8);
516 
517  cpu_model0[16] = '\0';
518  for (i = 15 ; i >= 0 ; i--) {
519  if (cpu_model0[i] != ' ')
520  break;
521  cpu_model0[i] = '\0';
522  }
523  cpu_model1[16] = '\0';
524  for (i = 15 ; i >= 0 ; i--) {
525  if (cpu_model1[i] != ' ')
526  break;
527  cpu_model1[i] = '\0';
528  }
529  cpu_ver[8] = '\0';
530  for (i = 7 ; i >= 0 ; i--) {
531  if (cpu_ver[i] != ' ')
532  break;
533  cpu_ver[i] = '\0';
534  }
535 
536  printk(KERN_INFO "M32R-mp information\n");
537  printk(KERN_INFO " On-chip CPUs : %d\n", nr_cpu);
538  printk(KERN_INFO " CPU model : %s/%s(%s)\n", cpu_model0,
539  cpu_model1, cpu_ver);
540 }
541 
542 /*
543  * The bootstrap kernel entry code has set these up. Save them for
544  * a given CPU
545  */
546 static void __init smp_store_cpu_info(int cpu_id)
547 {
548  struct cpuinfo_m32r *ci = cpu_data + cpu_id;
549 
550  *ci = boot_cpu_data;
552 }
553 
554 static void __init show_cpu_info(int cpu_id)
555 {
556  struct cpuinfo_m32r *ci = &cpu_data[cpu_id];
557 
558  printk("CPU#%d : ", cpu_id);
559 
560 #define PRINT_CLOCK(name, value) \
561  printk(name " clock %d.%02dMHz", \
562  ((value) / 1000000), ((value) % 1000000) / 10000)
563 
564  PRINT_CLOCK("CPU", (int)ci->cpu_clock);
565  PRINT_CLOCK(", Bus", (int)ci->bus_clock);
566  printk(", loops_per_jiffy[%ld]\n", ci->loops_per_jiffy);
567 }
568 
569 /*
570  * the frequency of the profiling timer can be changed
571  * by writing a multiplier value into /proc/profile.
572  */
573 int setup_profiling_timer(unsigned int multiplier)
574 {
575  int i;
576 
577  /*
578  * Sanity check. [at least 500 APIC cycles should be
579  * between APIC interrupts as a rule of thumb, to avoid
580  * irqs flooding us]
581  */
582  if ( (!multiplier) || (calibration_result / multiplier < 500))
583  return -EINVAL;
584 
585  /*
586  * Set the new multiplier for each CPU. CPUs don't start using the
587  * new values until the next timer interrupt in which they do process
588  * accounting. At that time they also adjust their APIC timers
589  * accordingly.
590  */
592  per_cpu(prof_multiplier, i) = multiplier;
593 
594  return 0;
595 }
596 
597 /* Initialize all maps between cpu number and apicids */
598 static void __init init_cpu_to_physid(void)
599 {
600  int i;
601 
602  for (i = 0 ; i < NR_CPUS ; i++) {
603  cpu_2_physid[i] = -1;
604  physid_2_cpu[i] = -1;
605  }
606 }
607 
608 /*
609  * set up a mapping between cpu and apicid. Uses logical apicids for multiquad,
610  * else physical apic ids
611  */
612 static void __init map_cpu_to_physid(int cpu_id, int phys_id)
613 {
614  physid_2_cpu[phys_id] = cpu_id;
615  cpu_2_physid[cpu_id] = phys_id;
616 }
617 
618 /*
619  * undo a mapping between cpu and apicid. Uses logical apicids for multiquad,
620  * else physical apic ids
621  */
622 static void __init unmap_cpu_to_physid(int cpu_id, int phys_id)
623 {
624  physid_2_cpu[phys_id] = -1;
625  cpu_2_physid[cpu_id] = -1;
626 }