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leon_smp.c
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1 /* leon_smp.c: Sparc-Leon SMP support.
2  *
3  * based on sun4m_smp.c
4  * Copyright (C) 1996 David S. Miller ([email protected])
5  * Copyright (C) 2009 Daniel Hellstrom ([email protected]) Aeroflex Gaisler AB
6  * Copyright (C) 2009 Konrad Eisele ([email protected]) Aeroflex Gaisler AB
7  */
8 
9 #include <asm/head.h>
10 
11 #include <linux/kernel.h>
12 #include <linux/sched.h>
13 #include <linux/threads.h>
14 #include <linux/smp.h>
15 #include <linux/interrupt.h>
16 #include <linux/kernel_stat.h>
17 #include <linux/of.h>
18 #include <linux/init.h>
19 #include <linux/spinlock.h>
20 #include <linux/mm.h>
21 #include <linux/swap.h>
22 #include <linux/profile.h>
23 #include <linux/pm.h>
24 #include <linux/delay.h>
25 #include <linux/gfp.h>
26 #include <linux/cpu.h>
27 #include <linux/clockchips.h>
28 
29 #include <asm/cacheflush.h>
30 #include <asm/tlbflush.h>
31 
32 #include <asm/ptrace.h>
33 #include <linux/atomic.h>
34 #include <asm/irq_regs.h>
35 #include <asm/traps.h>
36 
37 #include <asm/delay.h>
38 #include <asm/irq.h>
39 #include <asm/page.h>
40 #include <asm/pgalloc.h>
41 #include <asm/pgtable.h>
42 #include <asm/oplib.h>
43 #include <asm/cpudata.h>
44 #include <asm/asi.h>
45 #include <asm/leon.h>
46 #include <asm/leon_amba.h>
47 #include <asm/timer.h>
48 
49 #include "kernel.h"
50 
51 #include "irq.h"
52 
54 static int smp_processors_ready;
55 extern volatile unsigned long cpu_callin_map[NR_CPUS];
58 static void leon_ipi_init(void);
59 
60 /* IRQ number of LEON IPIs */
61 int leon_ipi_irq = LEON3_IRQ_IPI_DEFAULT;
62 
63 static inline unsigned long do_swap(volatile unsigned long *ptr,
64  unsigned long val)
65 {
66  __asm__ __volatile__("swapa [%2] %3, %0\n\t" : "=&r"(val)
67  : "0"(val), "r"(ptr), "i"(ASI_LEON_DCACHE_MISS)
68  : "memory");
69  return val;
70 }
71 
73 {
75 
76  local_ops->cache_all();
77  local_ops->tlb_all();
79 
80  notify_cpu_starting(cpuid);
81 
82  /* Get our local ticker going. */
83  register_percpu_ce(cpuid);
84 
86  smp_store_cpu_info(cpuid);
87 
88  local_ops->cache_all();
89  local_ops->tlb_all();
90 
91  /*
92  * Unblock the master CPU _only_ when the scheduler state
93  * of all secondary CPUs will be up-to-date, so after
94  * the SMP initialization the master will be just allowed
95  * to call the scheduler code.
96  * Allow master to continue.
97  */
98  do_swap(&cpu_callin_map[cpuid], 1);
99 
100  local_ops->cache_all();
101  local_ops->tlb_all();
102 
103  /* Fix idle thread fields. */
104  __asm__ __volatile__("ld [%0], %%g6\n\t" : : "r"(&current_set[cpuid])
105  : "memory" /* paranoid */);
106 
107  /* Attach to the address space of init_task. */
108  atomic_inc(&init_mm.mm_count);
109  current->active_mm = &init_mm;
110 
111  while (!cpumask_test_cpu(cpuid, &smp_commenced_mask))
112  mb();
113 
115  set_cpu_online(cpuid, true);
116 }
117 
118 /*
119  * Cycle through the processors asking the PROM to start each one.
120  */
121 
123 
125 {
126  unsigned long cfg = sparc_leon3_get_dcachecfg();
127  int me = smp_processor_id();
128 
129  if (ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg) > 4) {
130  printk(KERN_INFO "Note: SMP with snooping only works on 4k cache, found %dk(0x%x) on cpu %d, disabling caches\n",
131  (unsigned int)ASI_LEON3_SYSCTRL_CFG_SSIZE(cfg),
132  (unsigned int)cfg, (unsigned int)me);
133  sparc_leon3_disable_cache();
134  } else {
135  if (cfg & ASI_LEON3_SYSCTRL_CFG_SNOOPING) {
136  sparc_leon3_enable_snooping();
137  } else {
138  printk(KERN_INFO "Note: You have to enable snooping in the vhdl model cpu %d, disabling caches\n",
139  me);
140  sparc_leon3_disable_cache();
141  }
142  }
143 
144  local_ops->cache_all();
145  local_ops->tlb_all();
146 }
147 
148 void leon_smp_setbroadcast(unsigned int mask)
149 {
150  int broadcast =
151  ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
153  if (!broadcast) {
154  prom_printf("######## !!!! The irqmp-ctrl must have broadcast enabled, smp wont work !!!!! ####### nr cpus: %d\n",
155  leon_smp_nrcpus());
156  if (leon_smp_nrcpus() > 1) {
157  BUG();
158  } else {
159  prom_printf("continue anyway\n");
160  return;
161  }
162  }
163  LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpbroadcast), mask);
164 }
165 
166 unsigned int leon_smp_getbroadcast(void)
167 {
168  unsigned int mask;
169  mask = LEON_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpbroadcast));
170  return mask;
171 }
172 
174 {
175  int nrcpu =
176  ((LEON3_BYPASS_LOAD_PA(&(leon3_irqctrl_regs->mpstatus)) >>
177  LEON3_IRQMPSTATUS_CPUNR) & 0xf) + 1;
178  return nrcpu;
179 }
180 
182 {
183  int nrcpu = leon_smp_nrcpus();
184  int me = smp_processor_id();
185 
186  /* Setup IPI */
187  leon_ipi_init();
188 
189  printk(KERN_INFO "%d:(%d:%d) cpus mpirq at 0x%x\n", (unsigned int)me,
190  (unsigned int)nrcpu, (unsigned int)NR_CPUS,
191  (unsigned int)&(leon3_irqctrl_regs->mpstatus));
192 
193  leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, me);
194  leon_enable_irq_cpu(LEON3_IRQ_TICKER, me);
195  leon_enable_irq_cpu(leon_ipi_irq, me);
196 
197  leon_smp_setbroadcast(1 << LEON3_IRQ_TICKER);
198 
200  local_ops->cache_all();
201 
202 }
203 
205 {
206  int timeout;
207 
208  current_set[i] = task_thread_info(idle);
209 
210  /* See trampoline.S:leon_smp_cpu_startup for details...
211  * Initialize the contexts table
212  * Since the call to prom_startcpu() trashes the structure,
213  * we need to re-initialize it for each cpu
214  */
215  smp_penguin_ctable.which_io = 0;
216  smp_penguin_ctable.phys_addr = (unsigned int)srmmu_ctx_table_phys;
217  smp_penguin_ctable.reg_size = 0;
218 
219  /* whirrr, whirrr, whirrrrrrrrr... */
220  printk(KERN_INFO "Starting CPU %d : (irqmp: 0x%x)\n", (unsigned int)i,
221  (unsigned int)&leon3_irqctrl_regs->mpstatus);
222  local_ops->cache_all();
223 
224  /* Make sure all IRQs are of from the start for this new CPU */
226 
227  /* Wake one CPU */
228  LEON_BYPASS_STORE_PA(&(leon3_irqctrl_regs->mpstatus), 1 << i);
229 
230  /* wheee... it's going... */
231  for (timeout = 0; timeout < 10000; timeout++) {
232  if (cpu_callin_map[i])
233  break;
234  udelay(200);
235  }
236  printk(KERN_INFO "Started CPU %d\n", (unsigned int)i);
237 
238  if (!(cpu_callin_map[i])) {
239  printk(KERN_ERR "Processor %d is stuck.\n", i);
240  return -ENODEV;
241  } else {
242  leon_enable_irq_cpu(LEON3_IRQ_CROSS_CALL, i);
243  leon_enable_irq_cpu(LEON3_IRQ_TICKER, i);
244  leon_enable_irq_cpu(leon_ipi_irq, i);
245  }
246 
247  local_ops->cache_all();
248  return 0;
249 }
250 
252 {
253 
254  int i, first;
255  int *prev;
256 
257  /* setup cpu list for irq rotation */
258  first = 0;
259  prev = &first;
260  for (i = 0; i < NR_CPUS; i++) {
261  if (cpu_online(i)) {
262  *prev = i;
263  prev = &cpu_data(i).next;
264  }
265  }
266  *prev = first;
267  local_ops->cache_all();
268 
269  /* Free unneeded trap tables */
270  if (!cpu_present(1)) {
271  ClearPageReserved(virt_to_page(&trapbase_cpu1));
272  init_page_count(virt_to_page(&trapbase_cpu1));
273  free_page((unsigned long)&trapbase_cpu1);
274  totalram_pages++;
275  num_physpages++;
276  }
277  if (!cpu_present(2)) {
278  ClearPageReserved(virt_to_page(&trapbase_cpu2));
279  init_page_count(virt_to_page(&trapbase_cpu2));
280  free_page((unsigned long)&trapbase_cpu2);
281  totalram_pages++;
282  num_physpages++;
283  }
284  if (!cpu_present(3)) {
285  ClearPageReserved(virt_to_page(&trapbase_cpu3));
286  init_page_count(virt_to_page(&trapbase_cpu3));
287  free_page((unsigned long)&trapbase_cpu3);
288  totalram_pages++;
289  num_physpages++;
290  }
291  /* Ok, they are spinning and ready to go. */
292  smp_processors_ready = 1;
293 
294 }
295 
297 {
298 }
299 
301  int single;
302  int msk;
303  int resched;
304 };
305 
307 
308 /* Initialize IPIs on the LEON, in order to save IRQ resources only one IRQ
309  * is used for all three types of IPIs.
310  */
311 static void __init leon_ipi_init(void)
312 {
313  int cpu, len;
314  struct leon_ipi_work *work;
315  struct property *pp;
316  struct device_node *rootnp;
317  struct tt_entry *trap_table;
318  unsigned long flags;
319 
320  /* Find IPI IRQ or stick with default value */
321  rootnp = of_find_node_by_path("/ambapp0");
322  if (rootnp) {
323  pp = of_find_property(rootnp, "ipi_num", &len);
324  if (pp && (*(int *)pp->value))
325  leon_ipi_irq = *(int *)pp->value;
326  }
327  printk(KERN_INFO "leon: SMP IPIs at IRQ %d\n", leon_ipi_irq);
328 
329  /* Adjust so that we jump directly to smpleon_ipi */
330  local_irq_save(flags);
331  trap_table = &sparc_ttable[SP_TRAP_IRQ1 + (leon_ipi_irq - 1)];
332  trap_table->inst_three += smpleon_ipi - real_irq_entry;
333  local_ops->cache_all();
334  local_irq_restore(flags);
335 
336  for_each_possible_cpu(cpu) {
337  work = &per_cpu(leon_ipi_work, cpu);
338  work->single = work->msk = work->resched = 0;
339  }
340 }
341 
342 static void leon_send_ipi(int cpu, int level)
343 {
344  unsigned long mask;
345  mask = leon_get_irqmask(level);
346  LEON3_BYPASS_STORE_PA(&leon3_irqctrl_regs->force[cpu], mask);
347 }
348 
349 static void leon_ipi_single(int cpu)
350 {
351  struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
352 
353  /* Mark work */
354  work->single = 1;
355 
356  /* Generate IRQ on the CPU */
357  leon_send_ipi(cpu, leon_ipi_irq);
358 }
359 
360 static void leon_ipi_mask_one(int cpu)
361 {
362  struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
363 
364  /* Mark work */
365  work->msk = 1;
366 
367  /* Generate IRQ on the CPU */
368  leon_send_ipi(cpu, leon_ipi_irq);
369 }
370 
371 static void leon_ipi_resched(int cpu)
372 {
373  struct leon_ipi_work *work = &per_cpu(leon_ipi_work, cpu);
374 
375  /* Mark work */
376  work->resched = 1;
377 
378  /* Generate IRQ on the CPU (any IRQ will cause resched) */
379  leon_send_ipi(cpu, leon_ipi_irq);
380 }
381 
383 {
384  struct leon_ipi_work *work = &__get_cpu_var(leon_ipi_work);
385 
386  if (work->single) {
387  work->single = 0;
389  }
390  if (work->msk) {
391  work->msk = 0;
393  }
394  if (work->resched) {
395  work->resched = 0;
397  }
398 }
399 
400 static struct smp_funcall {
401  smpfunc_t func;
402  unsigned long arg1;
403  unsigned long arg2;
404  unsigned long arg3;
405  unsigned long arg4;
406  unsigned long arg5;
407  unsigned long processors_in[NR_CPUS]; /* Set when ipi entered. */
408  unsigned long processors_out[NR_CPUS]; /* Set when ipi exited. */
409 } ccall_info;
410 
411 static DEFINE_SPINLOCK(cross_call_lock);
412 
413 /* Cross calls must be serialized, at least currently. */
414 static void leon_cross_call(smpfunc_t func, cpumask_t mask, unsigned long arg1,
415  unsigned long arg2, unsigned long arg3,
416  unsigned long arg4)
417 {
418  if (smp_processors_ready) {
419  register int high = NR_CPUS - 1;
420  unsigned long flags;
421 
422  spin_lock_irqsave(&cross_call_lock, flags);
423 
424  {
425  /* If you make changes here, make sure gcc generates proper code... */
426  register smpfunc_t f asm("i0") = func;
427  register unsigned long a1 asm("i1") = arg1;
428  register unsigned long a2 asm("i2") = arg2;
429  register unsigned long a3 asm("i3") = arg3;
430  register unsigned long a4 asm("i4") = arg4;
431  register unsigned long a5 asm("i5") = 0;
432 
433  __asm__ __volatile__("std %0, [%6]\n\t"
434  "std %2, [%6 + 8]\n\t"
435  "std %4, [%6 + 16]\n\t" : :
436  "r"(f), "r"(a1), "r"(a2), "r"(a3),
437  "r"(a4), "r"(a5),
438  "r"(&ccall_info.func));
439  }
440 
441  /* Init receive/complete mapping, plus fire the IPI's off. */
442  {
443  register int i;
444 
445  cpumask_clear_cpu(smp_processor_id(), &mask);
446  cpumask_and(&mask, cpu_online_mask, &mask);
447  for (i = 0; i <= high; i++) {
448  if (cpumask_test_cpu(i, &mask)) {
449  ccall_info.processors_in[i] = 0;
450  ccall_info.processors_out[i] = 0;
451  leon_send_ipi(i, LEON3_IRQ_CROSS_CALL);
452 
453  }
454  }
455  }
456 
457  {
458  register int i;
459 
460  i = 0;
461  do {
462  if (!cpumask_test_cpu(i, &mask))
463  continue;
464 
465  while (!ccall_info.processors_in[i])
466  barrier();
467  } while (++i <= high);
468 
469  i = 0;
470  do {
471  if (!cpumask_test_cpu(i, &mask))
472  continue;
473 
474  while (!ccall_info.processors_out[i])
475  barrier();
476  } while (++i <= high);
477  }
478 
479  spin_unlock_irqrestore(&cross_call_lock, flags);
480  }
481 }
482 
483 /* Running cross calls. */
485 {
486  int i = smp_processor_id();
487 
488  ccall_info.processors_in[i] = 1;
489  ccall_info.func(ccall_info.arg1, ccall_info.arg2, ccall_info.arg3,
490  ccall_info.arg4, ccall_info.arg5);
491  ccall_info.processors_out[i] = 1;
492 }
493 
494 static const struct sparc32_ipi_ops leon_ipi_ops = {
495  .cross_call = leon_cross_call,
496  .resched = leon_ipi_resched,
497  .single = leon_ipi_single,
498  .mask_one = leon_ipi_mask_one,
499 };
500 
502 {
503  /* Patch ipi15 trap table */
504  t_nmi[1] = t_nmi[1] + (linux_trap_ipi15_leon - linux_trap_ipi15_sun4m);
505 
506  sparc32_ipi_ops = &leon_ipi_ops;
507 }