Merge branch 'for-linus' of git://oss.sgi.com:8090/xfs/xfs-2.6
[linux-2.6] / arch / sparc64 / kernel / smp.c
1 /* smp.c: Sparc64 SMP support.
2  *
3  * Copyright (C) 1997, 2007 David S. Miller (davem@davemloft.net)
4  */
5
6 #include <linux/module.h>
7 #include <linux/kernel.h>
8 #include <linux/sched.h>
9 #include <linux/mm.h>
10 #include <linux/pagemap.h>
11 #include <linux/threads.h>
12 #include <linux/smp.h>
13 #include <linux/interrupt.h>
14 #include <linux/kernel_stat.h>
15 #include <linux/delay.h>
16 #include <linux/init.h>
17 #include <linux/spinlock.h>
18 #include <linux/fs.h>
19 #include <linux/seq_file.h>
20 #include <linux/cache.h>
21 #include <linux/jiffies.h>
22 #include <linux/profile.h>
23 #include <linux/bootmem.h>
24
25 #include <asm/head.h>
26 #include <asm/ptrace.h>
27 #include <asm/atomic.h>
28 #include <asm/tlbflush.h>
29 #include <asm/mmu_context.h>
30 #include <asm/cpudata.h>
31 #include <asm/hvtramp.h>
32 #include <asm/io.h>
33
34 #include <asm/irq.h>
35 #include <asm/irq_regs.h>
36 #include <asm/page.h>
37 #include <asm/pgtable.h>
38 #include <asm/oplib.h>
39 #include <asm/uaccess.h>
40 #include <asm/timer.h>
41 #include <asm/starfire.h>
42 #include <asm/tlb.h>
43 #include <asm/sections.h>
44 #include <asm/prom.h>
45 #include <asm/mdesc.h>
46 #include <asm/ldc.h>
47 #include <asm/hypervisor.h>
48
49 int sparc64_multi_core __read_mostly;
50
51 cpumask_t cpu_possible_map __read_mostly = CPU_MASK_NONE;
52 cpumask_t cpu_online_map __read_mostly = CPU_MASK_NONE;
53 DEFINE_PER_CPU(cpumask_t, cpu_sibling_map) = CPU_MASK_NONE;
54 cpumask_t cpu_core_map[NR_CPUS] __read_mostly =
55         { [0 ... NR_CPUS-1] = CPU_MASK_NONE };
56
57 EXPORT_SYMBOL(cpu_possible_map);
58 EXPORT_SYMBOL(cpu_online_map);
59 EXPORT_PER_CPU_SYMBOL(cpu_sibling_map);
60 EXPORT_SYMBOL(cpu_core_map);
61
62 static cpumask_t smp_commenced_mask;
63
64 void smp_info(struct seq_file *m)
65 {
66         int i;
67         
68         seq_printf(m, "State:\n");
69         for_each_online_cpu(i)
70                 seq_printf(m, "CPU%d:\t\tonline\n", i);
71 }
72
73 void smp_bogo(struct seq_file *m)
74 {
75         int i;
76         
77         for_each_online_cpu(i)
78                 seq_printf(m,
79                            "Cpu%dClkTck\t: %016lx\n",
80                            i, cpu_data(i).clock_tick);
81 }
82
83 static __cacheline_aligned_in_smp DEFINE_SPINLOCK(call_lock);
84
85 extern void setup_sparc64_timer(void);
86
87 static volatile unsigned long callin_flag = 0;
88
89 void __devinit smp_callin(void)
90 {
91         int cpuid = hard_smp_processor_id();
92
93         __local_per_cpu_offset = __per_cpu_offset(cpuid);
94
95         if (tlb_type == hypervisor)
96                 sun4v_ktsb_register();
97
98         __flush_tlb_all();
99
100         setup_sparc64_timer();
101
102         if (cheetah_pcache_forced_on)
103                 cheetah_enable_pcache();
104
105         local_irq_enable();
106
107         callin_flag = 1;
108         __asm__ __volatile__("membar #Sync\n\t"
109                              "flush  %%g6" : : : "memory");
110
111         /* Clear this or we will die instantly when we
112          * schedule back to this idler...
113          */
114         current_thread_info()->new_child = 0;
115
116         /* Attach to the address space of init_task. */
117         atomic_inc(&init_mm.mm_count);
118         current->active_mm = &init_mm;
119
120         while (!cpu_isset(cpuid, smp_commenced_mask))
121                 rmb();
122
123         spin_lock(&call_lock);
124         cpu_set(cpuid, cpu_online_map);
125         spin_unlock(&call_lock);
126
127         /* idle thread is expected to have preempt disabled */
128         preempt_disable();
129 }
130
131 void cpu_panic(void)
132 {
133         printk("CPU[%d]: Returns from cpu_idle!\n", smp_processor_id());
134         panic("SMP bolixed\n");
135 }
136
137 /* This tick register synchronization scheme is taken entirely from
138  * the ia64 port, see arch/ia64/kernel/smpboot.c for details and credit.
139  *
140  * The only change I've made is to rework it so that the master
141  * initiates the synchonization instead of the slave. -DaveM
142  */
143
144 #define MASTER  0
145 #define SLAVE   (SMP_CACHE_BYTES/sizeof(unsigned long))
146
147 #define NUM_ROUNDS      64      /* magic value */
148 #define NUM_ITERS       5       /* likewise */
149
150 static DEFINE_SPINLOCK(itc_sync_lock);
151 static unsigned long go[SLAVE + 1];
152
153 #define DEBUG_TICK_SYNC 0
154
155 static inline long get_delta (long *rt, long *master)
156 {
157         unsigned long best_t0 = 0, best_t1 = ~0UL, best_tm = 0;
158         unsigned long tcenter, t0, t1, tm;
159         unsigned long i;
160
161         for (i = 0; i < NUM_ITERS; i++) {
162                 t0 = tick_ops->get_tick();
163                 go[MASTER] = 1;
164                 membar_storeload();
165                 while (!(tm = go[SLAVE]))
166                         rmb();
167                 go[SLAVE] = 0;
168                 wmb();
169                 t1 = tick_ops->get_tick();
170
171                 if (t1 - t0 < best_t1 - best_t0)
172                         best_t0 = t0, best_t1 = t1, best_tm = tm;
173         }
174
175         *rt = best_t1 - best_t0;
176         *master = best_tm - best_t0;
177
178         /* average best_t0 and best_t1 without overflow: */
179         tcenter = (best_t0/2 + best_t1/2);
180         if (best_t0 % 2 + best_t1 % 2 == 2)
181                 tcenter++;
182         return tcenter - best_tm;
183 }
184
185 void smp_synchronize_tick_client(void)
186 {
187         long i, delta, adj, adjust_latency = 0, done = 0;
188         unsigned long flags, rt, master_time_stamp, bound;
189 #if DEBUG_TICK_SYNC
190         struct {
191                 long rt;        /* roundtrip time */
192                 long master;    /* master's timestamp */
193                 long diff;      /* difference between midpoint and master's timestamp */
194                 long lat;       /* estimate of itc adjustment latency */
195         } t[NUM_ROUNDS];
196 #endif
197
198         go[MASTER] = 1;
199
200         while (go[MASTER])
201                 rmb();
202
203         local_irq_save(flags);
204         {
205                 for (i = 0; i < NUM_ROUNDS; i++) {
206                         delta = get_delta(&rt, &master_time_stamp);
207                         if (delta == 0) {
208                                 done = 1;       /* let's lock on to this... */
209                                 bound = rt;
210                         }
211
212                         if (!done) {
213                                 if (i > 0) {
214                                         adjust_latency += -delta;
215                                         adj = -delta + adjust_latency/4;
216                                 } else
217                                         adj = -delta;
218
219                                 tick_ops->add_tick(adj);
220                         }
221 #if DEBUG_TICK_SYNC
222                         t[i].rt = rt;
223                         t[i].master = master_time_stamp;
224                         t[i].diff = delta;
225                         t[i].lat = adjust_latency/4;
226 #endif
227                 }
228         }
229         local_irq_restore(flags);
230
231 #if DEBUG_TICK_SYNC
232         for (i = 0; i < NUM_ROUNDS; i++)
233                 printk("rt=%5ld master=%5ld diff=%5ld adjlat=%5ld\n",
234                        t[i].rt, t[i].master, t[i].diff, t[i].lat);
235 #endif
236
237         printk(KERN_INFO "CPU %d: synchronized TICK with master CPU "
238                "(last diff %ld cycles, maxerr %lu cycles)\n",
239                smp_processor_id(), delta, rt);
240 }
241
242 static void smp_start_sync_tick_client(int cpu);
243
244 static void smp_synchronize_one_tick(int cpu)
245 {
246         unsigned long flags, i;
247
248         go[MASTER] = 0;
249
250         smp_start_sync_tick_client(cpu);
251
252         /* wait for client to be ready */
253         while (!go[MASTER])
254                 rmb();
255
256         /* now let the client proceed into his loop */
257         go[MASTER] = 0;
258         membar_storeload();
259
260         spin_lock_irqsave(&itc_sync_lock, flags);
261         {
262                 for (i = 0; i < NUM_ROUNDS*NUM_ITERS; i++) {
263                         while (!go[MASTER])
264                                 rmb();
265                         go[MASTER] = 0;
266                         wmb();
267                         go[SLAVE] = tick_ops->get_tick();
268                         membar_storeload();
269                 }
270         }
271         spin_unlock_irqrestore(&itc_sync_lock, flags);
272 }
273
274 #if defined(CONFIG_SUN_LDOMS) && defined(CONFIG_HOTPLUG_CPU)
275 /* XXX Put this in some common place. XXX */
276 static unsigned long kimage_addr_to_ra(void *p)
277 {
278         unsigned long val = (unsigned long) p;
279
280         return kern_base + (val - KERNBASE);
281 }
282
283 static void ldom_startcpu_cpuid(unsigned int cpu, unsigned long thread_reg)
284 {
285         extern unsigned long sparc64_ttable_tl0;
286         extern unsigned long kern_locked_tte_data;
287         extern int bigkernel;
288         struct hvtramp_descr *hdesc;
289         unsigned long trampoline_ra;
290         struct trap_per_cpu *tb;
291         u64 tte_vaddr, tte_data;
292         unsigned long hv_err;
293
294         hdesc = kzalloc(sizeof(*hdesc), GFP_KERNEL);
295         if (!hdesc) {
296                 printk(KERN_ERR "ldom_startcpu_cpuid: Cannot allocate "
297                        "hvtramp_descr.\n");
298                 return;
299         }
300
301         hdesc->cpu = cpu;
302         hdesc->num_mappings = (bigkernel ? 2 : 1);
303
304         tb = &trap_block[cpu];
305         tb->hdesc = hdesc;
306
307         hdesc->fault_info_va = (unsigned long) &tb->fault_info;
308         hdesc->fault_info_pa = kimage_addr_to_ra(&tb->fault_info);
309
310         hdesc->thread_reg = thread_reg;
311
312         tte_vaddr = (unsigned long) KERNBASE;
313         tte_data = kern_locked_tte_data;
314
315         hdesc->maps[0].vaddr = tte_vaddr;
316         hdesc->maps[0].tte   = tte_data;
317         if (bigkernel) {
318                 tte_vaddr += 0x400000;
319                 tte_data  += 0x400000;
320                 hdesc->maps[1].vaddr = tte_vaddr;
321                 hdesc->maps[1].tte   = tte_data;
322         }
323
324         trampoline_ra = kimage_addr_to_ra(hv_cpu_startup);
325
326         hv_err = sun4v_cpu_start(cpu, trampoline_ra,
327                                  kimage_addr_to_ra(&sparc64_ttable_tl0),
328                                  __pa(hdesc));
329         if (hv_err)
330                 printk(KERN_ERR "ldom_startcpu_cpuid: sun4v_cpu_start() "
331                        "gives error %lu\n", hv_err);
332 }
333 #endif
334
335 extern unsigned long sparc64_cpu_startup;
336
337 /* The OBP cpu startup callback truncates the 3rd arg cookie to
338  * 32-bits (I think) so to be safe we have it read the pointer
339  * contained here so we work on >4GB machines. -DaveM
340  */
341 static struct thread_info *cpu_new_thread = NULL;
342
343 static int __devinit smp_boot_one_cpu(unsigned int cpu)
344 {
345         struct trap_per_cpu *tb = &trap_block[cpu];
346         unsigned long entry =
347                 (unsigned long)(&sparc64_cpu_startup);
348         unsigned long cookie =
349                 (unsigned long)(&cpu_new_thread);
350         struct task_struct *p;
351         int timeout, ret;
352
353         p = fork_idle(cpu);
354         if (IS_ERR(p))
355                 return PTR_ERR(p);
356         callin_flag = 0;
357         cpu_new_thread = task_thread_info(p);
358
359         if (tlb_type == hypervisor) {
360 #if defined(CONFIG_SUN_LDOMS) && defined(CONFIG_HOTPLUG_CPU)
361                 if (ldom_domaining_enabled)
362                         ldom_startcpu_cpuid(cpu,
363                                             (unsigned long) cpu_new_thread);
364                 else
365 #endif
366                         prom_startcpu_cpuid(cpu, entry, cookie);
367         } else {
368                 struct device_node *dp = of_find_node_by_cpuid(cpu);
369
370                 prom_startcpu(dp->node, entry, cookie);
371         }
372
373         for (timeout = 0; timeout < 50000; timeout++) {
374                 if (callin_flag)
375                         break;
376                 udelay(100);
377         }
378
379         if (callin_flag) {
380                 ret = 0;
381         } else {
382                 printk("Processor %d is stuck.\n", cpu);
383                 ret = -ENODEV;
384         }
385         cpu_new_thread = NULL;
386
387         if (tb->hdesc) {
388                 kfree(tb->hdesc);
389                 tb->hdesc = NULL;
390         }
391
392         return ret;
393 }
394
395 static void spitfire_xcall_helper(u64 data0, u64 data1, u64 data2, u64 pstate, unsigned long cpu)
396 {
397         u64 result, target;
398         int stuck, tmp;
399
400         if (this_is_starfire) {
401                 /* map to real upaid */
402                 cpu = (((cpu & 0x3c) << 1) |
403                         ((cpu & 0x40) >> 4) |
404                         (cpu & 0x3));
405         }
406
407         target = (cpu << 14) | 0x70;
408 again:
409         /* Ok, this is the real Spitfire Errata #54.
410          * One must read back from a UDB internal register
411          * after writes to the UDB interrupt dispatch, but
412          * before the membar Sync for that write.
413          * So we use the high UDB control register (ASI 0x7f,
414          * ADDR 0x20) for the dummy read. -DaveM
415          */
416         tmp = 0x40;
417         __asm__ __volatile__(
418         "wrpr   %1, %2, %%pstate\n\t"
419         "stxa   %4, [%0] %3\n\t"
420         "stxa   %5, [%0+%8] %3\n\t"
421         "add    %0, %8, %0\n\t"
422         "stxa   %6, [%0+%8] %3\n\t"
423         "membar #Sync\n\t"
424         "stxa   %%g0, [%7] %3\n\t"
425         "membar #Sync\n\t"
426         "mov    0x20, %%g1\n\t"
427         "ldxa   [%%g1] 0x7f, %%g0\n\t"
428         "membar #Sync"
429         : "=r" (tmp)
430         : "r" (pstate), "i" (PSTATE_IE), "i" (ASI_INTR_W),
431           "r" (data0), "r" (data1), "r" (data2), "r" (target),
432           "r" (0x10), "0" (tmp)
433         : "g1");
434
435         /* NOTE: PSTATE_IE is still clear. */
436         stuck = 100000;
437         do {
438                 __asm__ __volatile__("ldxa [%%g0] %1, %0"
439                         : "=r" (result)
440                         : "i" (ASI_INTR_DISPATCH_STAT));
441                 if (result == 0) {
442                         __asm__ __volatile__("wrpr %0, 0x0, %%pstate"
443                                              : : "r" (pstate));
444                         return;
445                 }
446                 stuck -= 1;
447                 if (stuck == 0)
448                         break;
449         } while (result & 0x1);
450         __asm__ __volatile__("wrpr %0, 0x0, %%pstate"
451                              : : "r" (pstate));
452         if (stuck == 0) {
453                 printk("CPU[%d]: mondo stuckage result[%016lx]\n",
454                        smp_processor_id(), result);
455         } else {
456                 udelay(2);
457                 goto again;
458         }
459 }
460
461 static inline void spitfire_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mask)
462 {
463         u64 pstate;
464         int i;
465
466         __asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
467         for_each_cpu_mask(i, mask)
468                 spitfire_xcall_helper(data0, data1, data2, pstate, i);
469 }
470
471 /* Cheetah now allows to send the whole 64-bytes of data in the interrupt
472  * packet, but we have no use for that.  However we do take advantage of
473  * the new pipelining feature (ie. dispatch to multiple cpus simultaneously).
474  */
475 static void cheetah_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mask)
476 {
477         u64 pstate, ver, busy_mask;
478         int nack_busy_id, is_jbus, need_more;
479
480         if (cpus_empty(mask))
481                 return;
482
483         /* Unfortunately, someone at Sun had the brilliant idea to make the
484          * busy/nack fields hard-coded by ITID number for this Ultra-III
485          * derivative processor.
486          */
487         __asm__ ("rdpr %%ver, %0" : "=r" (ver));
488         is_jbus = ((ver >> 32) == __JALAPENO_ID ||
489                    (ver >> 32) == __SERRANO_ID);
490
491         __asm__ __volatile__("rdpr %%pstate, %0" : "=r" (pstate));
492
493 retry:
494         need_more = 0;
495         __asm__ __volatile__("wrpr %0, %1, %%pstate\n\t"
496                              : : "r" (pstate), "i" (PSTATE_IE));
497
498         /* Setup the dispatch data registers. */
499         __asm__ __volatile__("stxa      %0, [%3] %6\n\t"
500                              "stxa      %1, [%4] %6\n\t"
501                              "stxa      %2, [%5] %6\n\t"
502                              "membar    #Sync\n\t"
503                              : /* no outputs */
504                              : "r" (data0), "r" (data1), "r" (data2),
505                                "r" (0x40), "r" (0x50), "r" (0x60),
506                                "i" (ASI_INTR_W));
507
508         nack_busy_id = 0;
509         busy_mask = 0;
510         {
511                 int i;
512
513                 for_each_cpu_mask(i, mask) {
514                         u64 target = (i << 14) | 0x70;
515
516                         if (is_jbus) {
517                                 busy_mask |= (0x1UL << (i * 2));
518                         } else {
519                                 target |= (nack_busy_id << 24);
520                                 busy_mask |= (0x1UL <<
521                                               (nack_busy_id * 2));
522                         }
523                         __asm__ __volatile__(
524                                 "stxa   %%g0, [%0] %1\n\t"
525                                 "membar #Sync\n\t"
526                                 : /* no outputs */
527                                 : "r" (target), "i" (ASI_INTR_W));
528                         nack_busy_id++;
529                         if (nack_busy_id == 32) {
530                                 need_more = 1;
531                                 break;
532                         }
533                 }
534         }
535
536         /* Now, poll for completion. */
537         {
538                 u64 dispatch_stat, nack_mask;
539                 long stuck;
540
541                 stuck = 100000 * nack_busy_id;
542                 nack_mask = busy_mask << 1;
543                 do {
544                         __asm__ __volatile__("ldxa      [%%g0] %1, %0"
545                                              : "=r" (dispatch_stat)
546                                              : "i" (ASI_INTR_DISPATCH_STAT));
547                         if (!(dispatch_stat & (busy_mask | nack_mask))) {
548                                 __asm__ __volatile__("wrpr %0, 0x0, %%pstate"
549                                                      : : "r" (pstate));
550                                 if (unlikely(need_more)) {
551                                         int i, cnt = 0;
552                                         for_each_cpu_mask(i, mask) {
553                                                 cpu_clear(i, mask);
554                                                 cnt++;
555                                                 if (cnt == 32)
556                                                         break;
557                                         }
558                                         goto retry;
559                                 }
560                                 return;
561                         }
562                         if (!--stuck)
563                                 break;
564                 } while (dispatch_stat & busy_mask);
565
566                 __asm__ __volatile__("wrpr %0, 0x0, %%pstate"
567                                      : : "r" (pstate));
568
569                 if (dispatch_stat & busy_mask) {
570                         /* Busy bits will not clear, continue instead
571                          * of freezing up on this cpu.
572                          */
573                         printk("CPU[%d]: mondo stuckage result[%016lx]\n",
574                                smp_processor_id(), dispatch_stat);
575                 } else {
576                         int i, this_busy_nack = 0;
577
578                         /* Delay some random time with interrupts enabled
579                          * to prevent deadlock.
580                          */
581                         udelay(2 * nack_busy_id);
582
583                         /* Clear out the mask bits for cpus which did not
584                          * NACK us.
585                          */
586                         for_each_cpu_mask(i, mask) {
587                                 u64 check_mask;
588
589                                 if (is_jbus)
590                                         check_mask = (0x2UL << (2*i));
591                                 else
592                                         check_mask = (0x2UL <<
593                                                       this_busy_nack);
594                                 if ((dispatch_stat & check_mask) == 0)
595                                         cpu_clear(i, mask);
596                                 this_busy_nack += 2;
597                                 if (this_busy_nack == 64)
598                                         break;
599                         }
600
601                         goto retry;
602                 }
603         }
604 }
605
606 /* Multi-cpu list version.  */
607 static void hypervisor_xcall_deliver(u64 data0, u64 data1, u64 data2, cpumask_t mask)
608 {
609         struct trap_per_cpu *tb;
610         u16 *cpu_list;
611         u64 *mondo;
612         cpumask_t error_mask;
613         unsigned long flags, status;
614         int cnt, retries, this_cpu, prev_sent, i;
615
616         if (cpus_empty(mask))
617                 return;
618
619         /* We have to do this whole thing with interrupts fully disabled.
620          * Otherwise if we send an xcall from interrupt context it will
621          * corrupt both our mondo block and cpu list state.
622          *
623          * One consequence of this is that we cannot use timeout mechanisms
624          * that depend upon interrupts being delivered locally.  So, for
625          * example, we cannot sample jiffies and expect it to advance.
626          *
627          * Fortunately, udelay() uses %stick/%tick so we can use that.
628          */
629         local_irq_save(flags);
630
631         this_cpu = smp_processor_id();
632         tb = &trap_block[this_cpu];
633
634         mondo = __va(tb->cpu_mondo_block_pa);
635         mondo[0] = data0;
636         mondo[1] = data1;
637         mondo[2] = data2;
638         wmb();
639
640         cpu_list = __va(tb->cpu_list_pa);
641
642         /* Setup the initial cpu list.  */
643         cnt = 0;
644         for_each_cpu_mask(i, mask)
645                 cpu_list[cnt++] = i;
646
647         cpus_clear(error_mask);
648         retries = 0;
649         prev_sent = 0;
650         do {
651                 int forward_progress, n_sent;
652
653                 status = sun4v_cpu_mondo_send(cnt,
654                                               tb->cpu_list_pa,
655                                               tb->cpu_mondo_block_pa);
656
657                 /* HV_EOK means all cpus received the xcall, we're done.  */
658                 if (likely(status == HV_EOK))
659                         break;
660
661                 /* First, see if we made any forward progress.
662                  *
663                  * The hypervisor indicates successful sends by setting
664                  * cpu list entries to the value 0xffff.
665                  */
666                 n_sent = 0;
667                 for (i = 0; i < cnt; i++) {
668                         if (likely(cpu_list[i] == 0xffff))
669                                 n_sent++;
670                 }
671
672                 forward_progress = 0;
673                 if (n_sent > prev_sent)
674                         forward_progress = 1;
675
676                 prev_sent = n_sent;
677
678                 /* If we get a HV_ECPUERROR, then one or more of the cpus
679                  * in the list are in error state.  Use the cpu_state()
680                  * hypervisor call to find out which cpus are in error state.
681                  */
682                 if (unlikely(status == HV_ECPUERROR)) {
683                         for (i = 0; i < cnt; i++) {
684                                 long err;
685                                 u16 cpu;
686
687                                 cpu = cpu_list[i];
688                                 if (cpu == 0xffff)
689                                         continue;
690
691                                 err = sun4v_cpu_state(cpu);
692                                 if (err >= 0 &&
693                                     err == HV_CPU_STATE_ERROR) {
694                                         cpu_list[i] = 0xffff;
695                                         cpu_set(cpu, error_mask);
696                                 }
697                         }
698                 } else if (unlikely(status != HV_EWOULDBLOCK))
699                         goto fatal_mondo_error;
700
701                 /* Don't bother rewriting the CPU list, just leave the
702                  * 0xffff and non-0xffff entries in there and the
703                  * hypervisor will do the right thing.
704                  *
705                  * Only advance timeout state if we didn't make any
706                  * forward progress.
707                  */
708                 if (unlikely(!forward_progress)) {
709                         if (unlikely(++retries > 10000))
710                                 goto fatal_mondo_timeout;
711
712                         /* Delay a little bit to let other cpus catch up
713                          * on their cpu mondo queue work.
714                          */
715                         udelay(2 * cnt);
716                 }
717         } while (1);
718
719         local_irq_restore(flags);
720
721         if (unlikely(!cpus_empty(error_mask)))
722                 goto fatal_mondo_cpu_error;
723
724         return;
725
726 fatal_mondo_cpu_error:
727         printk(KERN_CRIT "CPU[%d]: SUN4V mondo cpu error, some target cpus "
728                "were in error state\n",
729                this_cpu);
730         printk(KERN_CRIT "CPU[%d]: Error mask [ ", this_cpu);
731         for_each_cpu_mask(i, error_mask)
732                 printk("%d ", i);
733         printk("]\n");
734         return;
735
736 fatal_mondo_timeout:
737         local_irq_restore(flags);
738         printk(KERN_CRIT "CPU[%d]: SUN4V mondo timeout, no forward "
739                " progress after %d retries.\n",
740                this_cpu, retries);
741         goto dump_cpu_list_and_out;
742
743 fatal_mondo_error:
744         local_irq_restore(flags);
745         printk(KERN_CRIT "CPU[%d]: Unexpected SUN4V mondo error %lu\n",
746                this_cpu, status);
747         printk(KERN_CRIT "CPU[%d]: Args were cnt(%d) cpulist_pa(%lx) "
748                "mondo_block_pa(%lx)\n",
749                this_cpu, cnt, tb->cpu_list_pa, tb->cpu_mondo_block_pa);
750
751 dump_cpu_list_and_out:
752         printk(KERN_CRIT "CPU[%d]: CPU list [ ", this_cpu);
753         for (i = 0; i < cnt; i++)
754                 printk("%u ", cpu_list[i]);
755         printk("]\n");
756 }
757
758 /* Send cross call to all processors mentioned in MASK
759  * except self.
760  */
761 static void smp_cross_call_masked(unsigned long *func, u32 ctx, u64 data1, u64 data2, cpumask_t mask)
762 {
763         u64 data0 = (((u64)ctx)<<32 | (((u64)func) & 0xffffffff));
764         int this_cpu = get_cpu();
765
766         cpus_and(mask, mask, cpu_online_map);
767         cpu_clear(this_cpu, mask);
768
769         if (tlb_type == spitfire)
770                 spitfire_xcall_deliver(data0, data1, data2, mask);
771         else if (tlb_type == cheetah || tlb_type == cheetah_plus)
772                 cheetah_xcall_deliver(data0, data1, data2, mask);
773         else
774                 hypervisor_xcall_deliver(data0, data1, data2, mask);
775         /* NOTE: Caller runs local copy on master. */
776
777         put_cpu();
778 }
779
780 extern unsigned long xcall_sync_tick;
781
782 static void smp_start_sync_tick_client(int cpu)
783 {
784         cpumask_t mask = cpumask_of_cpu(cpu);
785
786         smp_cross_call_masked(&xcall_sync_tick,
787                               0, 0, 0, mask);
788 }
789
790 /* Send cross call to all processors except self. */
791 #define smp_cross_call(func, ctx, data1, data2) \
792         smp_cross_call_masked(func, ctx, data1, data2, cpu_online_map)
793
794 struct call_data_struct {
795         void (*func) (void *info);
796         void *info;
797         atomic_t finished;
798         int wait;
799 };
800
801 static struct call_data_struct *call_data;
802
803 extern unsigned long xcall_call_function;
804
805 /**
806  * smp_call_function(): Run a function on all other CPUs.
807  * @func: The function to run. This must be fast and non-blocking.
808  * @info: An arbitrary pointer to pass to the function.
809  * @nonatomic: currently unused.
810  * @wait: If true, wait (atomically) until function has completed on other CPUs.
811  *
812  * Returns 0 on success, else a negative status code. Does not return until
813  * remote CPUs are nearly ready to execute <<func>> or are or have executed.
814  *
815  * You must not call this function with disabled interrupts or from a
816  * hardware interrupt handler or from a bottom half handler.
817  */
818 static int smp_call_function_mask(void (*func)(void *info), void *info,
819                                   int nonatomic, int wait, cpumask_t mask)
820 {
821         struct call_data_struct data;
822         int cpus;
823
824         /* Can deadlock when called with interrupts disabled */
825         WARN_ON(irqs_disabled());
826
827         data.func = func;
828         data.info = info;
829         atomic_set(&data.finished, 0);
830         data.wait = wait;
831
832         spin_lock(&call_lock);
833
834         cpu_clear(smp_processor_id(), mask);
835         cpus = cpus_weight(mask);
836         if (!cpus)
837                 goto out_unlock;
838
839         call_data = &data;
840         mb();
841
842         smp_cross_call_masked(&xcall_call_function, 0, 0, 0, mask);
843
844         /* Wait for response */
845         while (atomic_read(&data.finished) != cpus)
846                 cpu_relax();
847
848 out_unlock:
849         spin_unlock(&call_lock);
850
851         return 0;
852 }
853
854 int smp_call_function(void (*func)(void *info), void *info,
855                       int nonatomic, int wait)
856 {
857         return smp_call_function_mask(func, info, nonatomic, wait,
858                                       cpu_online_map);
859 }
860
861 void smp_call_function_client(int irq, struct pt_regs *regs)
862 {
863         void (*func) (void *info) = call_data->func;
864         void *info = call_data->info;
865
866         clear_softint(1 << irq);
867         if (call_data->wait) {
868                 /* let initiator proceed only after completion */
869                 func(info);
870                 atomic_inc(&call_data->finished);
871         } else {
872                 /* let initiator proceed after getting data */
873                 atomic_inc(&call_data->finished);
874                 func(info);
875         }
876 }
877
878 static void tsb_sync(void *info)
879 {
880         struct trap_per_cpu *tp = &trap_block[raw_smp_processor_id()];
881         struct mm_struct *mm = info;
882
883         /* It is not valid to test "currrent->active_mm == mm" here.
884          *
885          * The value of "current" is not changed atomically with
886          * switch_mm().  But that's OK, we just need to check the
887          * current cpu's trap block PGD physical address.
888          */
889         if (tp->pgd_paddr == __pa(mm->pgd))
890                 tsb_context_switch(mm);
891 }
892
893 void smp_tsb_sync(struct mm_struct *mm)
894 {
895         smp_call_function_mask(tsb_sync, mm, 0, 1, mm->cpu_vm_mask);
896 }
897
898 extern unsigned long xcall_flush_tlb_mm;
899 extern unsigned long xcall_flush_tlb_pending;
900 extern unsigned long xcall_flush_tlb_kernel_range;
901 extern unsigned long xcall_report_regs;
902 extern unsigned long xcall_receive_signal;
903 extern unsigned long xcall_new_mmu_context_version;
904
905 #ifdef DCACHE_ALIASING_POSSIBLE
906 extern unsigned long xcall_flush_dcache_page_cheetah;
907 #endif
908 extern unsigned long xcall_flush_dcache_page_spitfire;
909
910 #ifdef CONFIG_DEBUG_DCFLUSH
911 extern atomic_t dcpage_flushes;
912 extern atomic_t dcpage_flushes_xcall;
913 #endif
914
915 static inline void __local_flush_dcache_page(struct page *page)
916 {
917 #ifdef DCACHE_ALIASING_POSSIBLE
918         __flush_dcache_page(page_address(page),
919                             ((tlb_type == spitfire) &&
920                              page_mapping(page) != NULL));
921 #else
922         if (page_mapping(page) != NULL &&
923             tlb_type == spitfire)
924                 __flush_icache_page(__pa(page_address(page)));
925 #endif
926 }
927
928 void smp_flush_dcache_page_impl(struct page *page, int cpu)
929 {
930         cpumask_t mask = cpumask_of_cpu(cpu);
931         int this_cpu;
932
933         if (tlb_type == hypervisor)
934                 return;
935
936 #ifdef CONFIG_DEBUG_DCFLUSH
937         atomic_inc(&dcpage_flushes);
938 #endif
939
940         this_cpu = get_cpu();
941
942         if (cpu == this_cpu) {
943                 __local_flush_dcache_page(page);
944         } else if (cpu_online(cpu)) {
945                 void *pg_addr = page_address(page);
946                 u64 data0;
947
948                 if (tlb_type == spitfire) {
949                         data0 =
950                                 ((u64)&xcall_flush_dcache_page_spitfire);
951                         if (page_mapping(page) != NULL)
952                                 data0 |= ((u64)1 << 32);
953                         spitfire_xcall_deliver(data0,
954                                                __pa(pg_addr),
955                                                (u64) pg_addr,
956                                                mask);
957                 } else if (tlb_type == cheetah || tlb_type == cheetah_plus) {
958 #ifdef DCACHE_ALIASING_POSSIBLE
959                         data0 =
960                                 ((u64)&xcall_flush_dcache_page_cheetah);
961                         cheetah_xcall_deliver(data0,
962                                               __pa(pg_addr),
963                                               0, mask);
964 #endif
965                 }
966 #ifdef CONFIG_DEBUG_DCFLUSH
967                 atomic_inc(&dcpage_flushes_xcall);
968 #endif
969         }
970
971         put_cpu();
972 }
973
974 void flush_dcache_page_all(struct mm_struct *mm, struct page *page)
975 {
976         void *pg_addr = page_address(page);
977         cpumask_t mask = cpu_online_map;
978         u64 data0;
979         int this_cpu;
980
981         if (tlb_type == hypervisor)
982                 return;
983
984         this_cpu = get_cpu();
985
986         cpu_clear(this_cpu, mask);
987
988 #ifdef CONFIG_DEBUG_DCFLUSH
989         atomic_inc(&dcpage_flushes);
990 #endif
991         if (cpus_empty(mask))
992                 goto flush_self;
993         if (tlb_type == spitfire) {
994                 data0 = ((u64)&xcall_flush_dcache_page_spitfire);
995                 if (page_mapping(page) != NULL)
996                         data0 |= ((u64)1 << 32);
997                 spitfire_xcall_deliver(data0,
998                                        __pa(pg_addr),
999                                        (u64) pg_addr,
1000                                        mask);
1001         } else if (tlb_type == cheetah || tlb_type == cheetah_plus) {
1002 #ifdef DCACHE_ALIASING_POSSIBLE
1003                 data0 = ((u64)&xcall_flush_dcache_page_cheetah);
1004                 cheetah_xcall_deliver(data0,
1005                                       __pa(pg_addr),
1006                                       0, mask);
1007 #endif
1008         }
1009 #ifdef CONFIG_DEBUG_DCFLUSH
1010         atomic_inc(&dcpage_flushes_xcall);
1011 #endif
1012  flush_self:
1013         __local_flush_dcache_page(page);
1014
1015         put_cpu();
1016 }
1017
1018 static void __smp_receive_signal_mask(cpumask_t mask)
1019 {
1020         smp_cross_call_masked(&xcall_receive_signal, 0, 0, 0, mask);
1021 }
1022
1023 void smp_receive_signal(int cpu)
1024 {
1025         cpumask_t mask = cpumask_of_cpu(cpu);
1026
1027         if (cpu_online(cpu))
1028                 __smp_receive_signal_mask(mask);
1029 }
1030
1031 void smp_receive_signal_client(int irq, struct pt_regs *regs)
1032 {
1033         clear_softint(1 << irq);
1034 }
1035
1036 void smp_new_mmu_context_version_client(int irq, struct pt_regs *regs)
1037 {
1038         struct mm_struct *mm;
1039         unsigned long flags;
1040
1041         clear_softint(1 << irq);
1042
1043         /* See if we need to allocate a new TLB context because
1044          * the version of the one we are using is now out of date.
1045          */
1046         mm = current->active_mm;
1047         if (unlikely(!mm || (mm == &init_mm)))
1048                 return;
1049
1050         spin_lock_irqsave(&mm->context.lock, flags);
1051
1052         if (unlikely(!CTX_VALID(mm->context)))
1053                 get_new_mmu_context(mm);
1054
1055         spin_unlock_irqrestore(&mm->context.lock, flags);
1056
1057         load_secondary_context(mm);
1058         __flush_tlb_mm(CTX_HWBITS(mm->context),
1059                        SECONDARY_CONTEXT);
1060 }
1061
1062 void smp_new_mmu_context_version(void)
1063 {
1064         smp_cross_call(&xcall_new_mmu_context_version, 0, 0, 0);
1065 }
1066
1067 void smp_report_regs(void)
1068 {
1069         smp_cross_call(&xcall_report_regs, 0, 0, 0);
1070 }
1071
1072 /* We know that the window frames of the user have been flushed
1073  * to the stack before we get here because all callers of us
1074  * are flush_tlb_*() routines, and these run after flush_cache_*()
1075  * which performs the flushw.
1076  *
1077  * The SMP TLB coherency scheme we use works as follows:
1078  *
1079  * 1) mm->cpu_vm_mask is a bit mask of which cpus an address
1080  *    space has (potentially) executed on, this is the heuristic
1081  *    we use to avoid doing cross calls.
1082  *
1083  *    Also, for flushing from kswapd and also for clones, we
1084  *    use cpu_vm_mask as the list of cpus to make run the TLB.
1085  *
1086  * 2) TLB context numbers are shared globally across all processors
1087  *    in the system, this allows us to play several games to avoid
1088  *    cross calls.
1089  *
1090  *    One invariant is that when a cpu switches to a process, and
1091  *    that processes tsk->active_mm->cpu_vm_mask does not have the
1092  *    current cpu's bit set, that tlb context is flushed locally.
1093  *
1094  *    If the address space is non-shared (ie. mm->count == 1) we avoid
1095  *    cross calls when we want to flush the currently running process's
1096  *    tlb state.  This is done by clearing all cpu bits except the current
1097  *    processor's in current->active_mm->cpu_vm_mask and performing the
1098  *    flush locally only.  This will force any subsequent cpus which run
1099  *    this task to flush the context from the local tlb if the process
1100  *    migrates to another cpu (again).
1101  *
1102  * 3) For shared address spaces (threads) and swapping we bite the
1103  *    bullet for most cases and perform the cross call (but only to
1104  *    the cpus listed in cpu_vm_mask).
1105  *
1106  *    The performance gain from "optimizing" away the cross call for threads is
1107  *    questionable (in theory the big win for threads is the massive sharing of
1108  *    address space state across processors).
1109  */
1110
1111 /* This currently is only used by the hugetlb arch pre-fault
1112  * hook on UltraSPARC-III+ and later when changing the pagesize
1113  * bits of the context register for an address space.
1114  */
1115 void smp_flush_tlb_mm(struct mm_struct *mm)
1116 {
1117         u32 ctx = CTX_HWBITS(mm->context);
1118         int cpu = get_cpu();
1119
1120         if (atomic_read(&mm->mm_users) == 1) {
1121                 mm->cpu_vm_mask = cpumask_of_cpu(cpu);
1122                 goto local_flush_and_out;
1123         }
1124
1125         smp_cross_call_masked(&xcall_flush_tlb_mm,
1126                               ctx, 0, 0,
1127                               mm->cpu_vm_mask);
1128
1129 local_flush_and_out:
1130         __flush_tlb_mm(ctx, SECONDARY_CONTEXT);
1131
1132         put_cpu();
1133 }
1134
1135 void smp_flush_tlb_pending(struct mm_struct *mm, unsigned long nr, unsigned long *vaddrs)
1136 {
1137         u32 ctx = CTX_HWBITS(mm->context);
1138         int cpu = get_cpu();
1139
1140         if (mm == current->active_mm && atomic_read(&mm->mm_users) == 1)
1141                 mm->cpu_vm_mask = cpumask_of_cpu(cpu);
1142         else
1143                 smp_cross_call_masked(&xcall_flush_tlb_pending,
1144                                       ctx, nr, (unsigned long) vaddrs,
1145                                       mm->cpu_vm_mask);
1146
1147         __flush_tlb_pending(ctx, nr, vaddrs);
1148
1149         put_cpu();
1150 }
1151
1152 void smp_flush_tlb_kernel_range(unsigned long start, unsigned long end)
1153 {
1154         start &= PAGE_MASK;
1155         end    = PAGE_ALIGN(end);
1156         if (start != end) {
1157                 smp_cross_call(&xcall_flush_tlb_kernel_range,
1158                                0, start, end);
1159
1160                 __flush_tlb_kernel_range(start, end);
1161         }
1162 }
1163
1164 /* CPU capture. */
1165 /* #define CAPTURE_DEBUG */
1166 extern unsigned long xcall_capture;
1167
1168 static atomic_t smp_capture_depth = ATOMIC_INIT(0);
1169 static atomic_t smp_capture_registry = ATOMIC_INIT(0);
1170 static unsigned long penguins_are_doing_time;
1171
1172 void smp_capture(void)
1173 {
1174         int result = atomic_add_ret(1, &smp_capture_depth);
1175
1176         if (result == 1) {
1177                 int ncpus = num_online_cpus();
1178
1179 #ifdef CAPTURE_DEBUG
1180                 printk("CPU[%d]: Sending penguins to jail...",
1181                        smp_processor_id());
1182 #endif
1183                 penguins_are_doing_time = 1;
1184                 membar_storestore_loadstore();
1185                 atomic_inc(&smp_capture_registry);
1186                 smp_cross_call(&xcall_capture, 0, 0, 0);
1187                 while (atomic_read(&smp_capture_registry) != ncpus)
1188                         rmb();
1189 #ifdef CAPTURE_DEBUG
1190                 printk("done\n");
1191 #endif
1192         }
1193 }
1194
1195 void smp_release(void)
1196 {
1197         if (atomic_dec_and_test(&smp_capture_depth)) {
1198 #ifdef CAPTURE_DEBUG
1199                 printk("CPU[%d]: Giving pardon to "
1200                        "imprisoned penguins\n",
1201                        smp_processor_id());
1202 #endif
1203                 penguins_are_doing_time = 0;
1204                 membar_storeload_storestore();
1205                 atomic_dec(&smp_capture_registry);
1206         }
1207 }
1208
1209 /* Imprisoned penguins run with %pil == 15, but PSTATE_IE set, so they
1210  * can service tlb flush xcalls...
1211  */
1212 extern void prom_world(int);
1213
1214 void smp_penguin_jailcell(int irq, struct pt_regs *regs)
1215 {
1216         clear_softint(1 << irq);
1217
1218         preempt_disable();
1219
1220         __asm__ __volatile__("flushw");
1221         prom_world(1);
1222         atomic_inc(&smp_capture_registry);
1223         membar_storeload_storestore();
1224         while (penguins_are_doing_time)
1225                 rmb();
1226         atomic_dec(&smp_capture_registry);
1227         prom_world(0);
1228
1229         preempt_enable();
1230 }
1231
1232 /* /proc/profile writes can call this, don't __init it please. */
1233 int setup_profiling_timer(unsigned int multiplier)
1234 {
1235         return -EINVAL;
1236 }
1237
1238 void __init smp_prepare_cpus(unsigned int max_cpus)
1239 {
1240 }
1241
1242 void __devinit smp_prepare_boot_cpu(void)
1243 {
1244 }
1245
1246 void __devinit smp_fill_in_sib_core_maps(void)
1247 {
1248         unsigned int i;
1249
1250         for_each_present_cpu(i) {
1251                 unsigned int j;
1252
1253                 cpus_clear(cpu_core_map[i]);
1254                 if (cpu_data(i).core_id == 0) {
1255                         cpu_set(i, cpu_core_map[i]);
1256                         continue;
1257                 }
1258
1259                 for_each_present_cpu(j) {
1260                         if (cpu_data(i).core_id ==
1261                             cpu_data(j).core_id)
1262                                 cpu_set(j, cpu_core_map[i]);
1263                 }
1264         }
1265
1266         for_each_present_cpu(i) {
1267                 unsigned int j;
1268
1269                 cpus_clear(per_cpu(cpu_sibling_map, i));
1270                 if (cpu_data(i).proc_id == -1) {
1271                         cpu_set(i, per_cpu(cpu_sibling_map, i));
1272                         continue;
1273                 }
1274
1275                 for_each_present_cpu(j) {
1276                         if (cpu_data(i).proc_id ==
1277                             cpu_data(j).proc_id)
1278                                 cpu_set(j, per_cpu(cpu_sibling_map, i));
1279                 }
1280         }
1281 }
1282
1283 int __cpuinit __cpu_up(unsigned int cpu)
1284 {
1285         int ret = smp_boot_one_cpu(cpu);
1286
1287         if (!ret) {
1288                 cpu_set(cpu, smp_commenced_mask);
1289                 while (!cpu_isset(cpu, cpu_online_map))
1290                         mb();
1291                 if (!cpu_isset(cpu, cpu_online_map)) {
1292                         ret = -ENODEV;
1293                 } else {
1294                         /* On SUN4V, writes to %tick and %stick are
1295                          * not allowed.
1296                          */
1297                         if (tlb_type != hypervisor)
1298                                 smp_synchronize_one_tick(cpu);
1299                 }
1300         }
1301         return ret;
1302 }
1303
1304 #ifdef CONFIG_HOTPLUG_CPU
1305 void cpu_play_dead(void)
1306 {
1307         int cpu = smp_processor_id();
1308         unsigned long pstate;
1309
1310         idle_task_exit();
1311
1312         if (tlb_type == hypervisor) {
1313                 struct trap_per_cpu *tb = &trap_block[cpu];
1314
1315                 sun4v_cpu_qconf(HV_CPU_QUEUE_CPU_MONDO,
1316                                 tb->cpu_mondo_pa, 0);
1317                 sun4v_cpu_qconf(HV_CPU_QUEUE_DEVICE_MONDO,
1318                                 tb->dev_mondo_pa, 0);
1319                 sun4v_cpu_qconf(HV_CPU_QUEUE_RES_ERROR,
1320                                 tb->resum_mondo_pa, 0);
1321                 sun4v_cpu_qconf(HV_CPU_QUEUE_NONRES_ERROR,
1322                                 tb->nonresum_mondo_pa, 0);
1323         }
1324
1325         cpu_clear(cpu, smp_commenced_mask);
1326         membar_safe("#Sync");
1327
1328         local_irq_disable();
1329
1330         __asm__ __volatile__(
1331                 "rdpr   %%pstate, %0\n\t"
1332                 "wrpr   %0, %1, %%pstate"
1333                 : "=r" (pstate)
1334                 : "i" (PSTATE_IE));
1335
1336         while (1)
1337                 barrier();
1338 }
1339
1340 int __cpu_disable(void)
1341 {
1342         int cpu = smp_processor_id();
1343         cpuinfo_sparc *c;
1344         int i;
1345
1346         for_each_cpu_mask(i, cpu_core_map[cpu])
1347                 cpu_clear(cpu, cpu_core_map[i]);
1348         cpus_clear(cpu_core_map[cpu]);
1349
1350         for_each_cpu_mask(i, per_cpu(cpu_sibling_map, cpu))
1351                 cpu_clear(cpu, per_cpu(cpu_sibling_map, i));
1352         cpus_clear(per_cpu(cpu_sibling_map, cpu));
1353
1354         c = &cpu_data(cpu);
1355
1356         c->core_id = 0;
1357         c->proc_id = -1;
1358
1359         spin_lock(&call_lock);
1360         cpu_clear(cpu, cpu_online_map);
1361         spin_unlock(&call_lock);
1362
1363         smp_wmb();
1364
1365         /* Make sure no interrupts point to this cpu.  */
1366         fixup_irqs();
1367
1368         local_irq_enable();
1369         mdelay(1);
1370         local_irq_disable();
1371
1372         return 0;
1373 }
1374
1375 void __cpu_die(unsigned int cpu)
1376 {
1377         int i;
1378
1379         for (i = 0; i < 100; i++) {
1380                 smp_rmb();
1381                 if (!cpu_isset(cpu, smp_commenced_mask))
1382                         break;
1383                 msleep(100);
1384         }
1385         if (cpu_isset(cpu, smp_commenced_mask)) {
1386                 printk(KERN_ERR "CPU %u didn't die...\n", cpu);
1387         } else {
1388 #if defined(CONFIG_SUN_LDOMS)
1389                 unsigned long hv_err;
1390                 int limit = 100;
1391
1392                 do {
1393                         hv_err = sun4v_cpu_stop(cpu);
1394                         if (hv_err == HV_EOK) {
1395                                 cpu_clear(cpu, cpu_present_map);
1396                                 break;
1397                         }
1398                 } while (--limit > 0);
1399                 if (limit <= 0) {
1400                         printk(KERN_ERR "sun4v_cpu_stop() fails err=%lu\n",
1401                                hv_err);
1402                 }
1403 #endif
1404         }
1405 }
1406 #endif
1407
1408 void __init smp_cpus_done(unsigned int max_cpus)
1409 {
1410 }
1411
1412 void smp_send_reschedule(int cpu)
1413 {
1414         smp_receive_signal(cpu);
1415 }
1416
1417 /* This is a nop because we capture all other cpus
1418  * anyways when making the PROM active.
1419  */
1420 void smp_send_stop(void)
1421 {
1422 }
1423
1424 unsigned long __per_cpu_base __read_mostly;
1425 unsigned long __per_cpu_shift __read_mostly;
1426
1427 EXPORT_SYMBOL(__per_cpu_base);
1428 EXPORT_SYMBOL(__per_cpu_shift);
1429
1430 void __init real_setup_per_cpu_areas(void)
1431 {
1432         unsigned long goal, size, i;
1433         char *ptr;
1434
1435         /* Copy section for each CPU (we discard the original) */
1436         goal = PERCPU_ENOUGH_ROOM;
1437
1438         __per_cpu_shift = PAGE_SHIFT;
1439         for (size = PAGE_SIZE; size < goal; size <<= 1UL)
1440                 __per_cpu_shift++;
1441
1442         ptr = alloc_bootmem_pages(size * NR_CPUS);
1443
1444         __per_cpu_base = ptr - __per_cpu_start;
1445
1446         for (i = 0; i < NR_CPUS; i++, ptr += size)
1447                 memcpy(ptr, __per_cpu_start, __per_cpu_end - __per_cpu_start);
1448
1449         /* Setup %g5 for the boot cpu.  */
1450         __local_per_cpu_offset = __per_cpu_offset(smp_processor_id());
1451 }