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irq_ia64.c
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1 /*
2  * linux/arch/ia64/kernel/irq_ia64.c
3  *
4  * Copyright (C) 1998-2001 Hewlett-Packard Co
5  * Stephane Eranian <[email protected]>
6  * David Mosberger-Tang <[email protected]>
7  *
8  * 6/10/99: Updated to bring in sync with x86 version to facilitate
9  * support for SMP and different interrupt controllers.
10  *
11  * 09/15/00 Goutham Rao <[email protected]> Implemented pci_irq_to_vector
12  * PCI to vector allocation routine.
13  * 04/14/2004 Ashok Raj <[email protected]>
14  * Added CPU Hotplug handling for IPF.
15  */
16 
17 #include <linux/module.h>
18 
19 #include <linux/jiffies.h>
20 #include <linux/errno.h>
21 #include <linux/init.h>
22 #include <linux/interrupt.h>
23 #include <linux/ioport.h>
24 #include <linux/kernel_stat.h>
25 #include <linux/ptrace.h>
26 #include <linux/signal.h>
27 #include <linux/smp.h>
28 #include <linux/threads.h>
29 #include <linux/bitops.h>
30 #include <linux/irq.h>
31 #include <linux/ratelimit.h>
32 #include <linux/acpi.h>
33 #include <linux/sched.h>
34 
35 #include <asm/delay.h>
36 #include <asm/intrinsics.h>
37 #include <asm/io.h>
38 #include <asm/hw_irq.h>
39 #include <asm/machvec.h>
40 #include <asm/pgtable.h>
41 #include <asm/tlbflush.h>
42 
43 #ifdef CONFIG_PERFMON
44 # include <asm/perfmon.h>
45 #endif
46 
47 #define IRQ_DEBUG 0
48 
49 #define IRQ_VECTOR_UNASSIGNED (0)
50 
51 #define IRQ_UNUSED (0)
52 #define IRQ_USED (1)
53 #define IRQ_RSVD (2)
54 
55 /* These can be overridden in platform_irq_init */
58 
59 /* default base addr of IPI table */
60 void __iomem *ipi_base_addr = ((void __iomem *)
62 
63 static cpumask_t vector_allocation_domain(int cpu);
64 
65 /*
66  * Legacy IRQ to IA-64 vector translation table.
67  */
69  /* 8259 IRQ translation, first 16 entries */
70  0x2f, 0x20, 0x2e, 0x2d, 0x2c, 0x2b, 0x2a, 0x29,
71  0x28, 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21
72 };
73 EXPORT_SYMBOL(isa_irq_to_vector_map);
74 
75 DEFINE_SPINLOCK(vector_lock);
76 
78  [0 ... NR_IRQS - 1] = {
79  .vector = IRQ_VECTOR_UNASSIGNED,
80  .domain = CPU_MASK_NONE
81  }
82 };
83 
84 DEFINE_PER_CPU(int[IA64_NUM_VECTORS], vector_irq) = {
85  [0 ... IA64_NUM_VECTORS - 1] = -1
86 };
87 
88 static cpumask_t vector_table[IA64_NUM_VECTORS] = {
89  [0 ... IA64_NUM_VECTORS - 1] = CPU_MASK_NONE
90 };
91 
92 static int irq_status[NR_IRQS] = {
93  [0 ... NR_IRQS -1] = IRQ_UNUSED
94 };
95 
96 int check_irq_used(int irq)
97 {
98  if (irq_status[irq] == IRQ_USED)
99  return 1;
100 
101  return -1;
102 }
103 
104 static inline int find_unassigned_irq(void)
105 {
106  int irq;
107 
108  for (irq = IA64_FIRST_DEVICE_VECTOR; irq < NR_IRQS; irq++)
109  if (irq_status[irq] == IRQ_UNUSED)
110  return irq;
111  return -ENOSPC;
112 }
113 
114 static inline int find_unassigned_vector(cpumask_t domain)
115 {
116  cpumask_t mask;
117  int pos, vector;
118 
119  cpumask_and(&mask, &domain, cpu_online_mask);
120  if (cpus_empty(mask))
121  return -EINVAL;
122 
123  for (pos = 0; pos < IA64_NUM_DEVICE_VECTORS; pos++) {
124  vector = IA64_FIRST_DEVICE_VECTOR + pos;
125  cpus_and(mask, domain, vector_table[vector]);
126  if (!cpus_empty(mask))
127  continue;
128  return vector;
129  }
130  return -ENOSPC;
131 }
132 
133 static int __bind_irq_vector(int irq, int vector, cpumask_t domain)
134 {
135  cpumask_t mask;
136  int cpu;
137  struct irq_cfg *cfg = &irq_cfg[irq];
138 
139  BUG_ON((unsigned)irq >= NR_IRQS);
140  BUG_ON((unsigned)vector >= IA64_NUM_VECTORS);
141 
142  cpumask_and(&mask, &domain, cpu_online_mask);
143  if (cpus_empty(mask))
144  return -EINVAL;
145  if ((cfg->vector == vector) && cpus_equal(cfg->domain, domain))
146  return 0;
147  if (cfg->vector != IRQ_VECTOR_UNASSIGNED)
148  return -EBUSY;
149  for_each_cpu_mask(cpu, mask)
150  per_cpu(vector_irq, cpu)[vector] = irq;
151  cfg->vector = vector;
152  cfg->domain = domain;
153  irq_status[irq] = IRQ_USED;
154  cpus_or(vector_table[vector], vector_table[vector], domain);
155  return 0;
156 }
157 
158 int bind_irq_vector(int irq, int vector, cpumask_t domain)
159 {
160  unsigned long flags;
161  int ret;
162 
164  ret = __bind_irq_vector(irq, vector, domain);
165  spin_unlock_irqrestore(&vector_lock, flags);
166  return ret;
167 }
168 
169 static void __clear_irq_vector(int irq)
170 {
171  int vector, cpu;
172  cpumask_t mask;
174  struct irq_cfg *cfg = &irq_cfg[irq];
175 
176  BUG_ON((unsigned)irq >= NR_IRQS);
178  vector = cfg->vector;
179  domain = cfg->domain;
180  cpumask_and(&mask, &cfg->domain, cpu_online_mask);
181  for_each_cpu_mask(cpu, mask)
182  per_cpu(vector_irq, cpu)[vector] = -1;
183  cfg->vector = IRQ_VECTOR_UNASSIGNED;
184  cfg->domain = CPU_MASK_NONE;
185  irq_status[irq] = IRQ_UNUSED;
186  cpus_andnot(vector_table[vector], vector_table[vector], domain);
187 }
188 
189 static void clear_irq_vector(int irq)
190 {
191  unsigned long flags;
192 
193  spin_lock_irqsave(&vector_lock, flags);
194  __clear_irq_vector(irq);
195  spin_unlock_irqrestore(&vector_lock, flags);
196 }
197 
198 int
200 {
201  unsigned long flags;
202  int vector, cpu;
203  cpumask_t domain = CPU_MASK_NONE;
204 
205  vector = -ENOSPC;
206 
208  for_each_online_cpu(cpu) {
209  domain = vector_allocation_domain(cpu);
210  vector = find_unassigned_vector(domain);
211  if (vector >= 0)
212  break;
213  }
214  if (vector < 0)
215  goto out;
216  if (irq == AUTO_ASSIGN)
217  irq = vector;
218  BUG_ON(__bind_irq_vector(irq, vector, domain));
219  out:
220  spin_unlock_irqrestore(&vector_lock, flags);
221  return vector;
222 }
223 
224 void
226 {
227  if (vector < IA64_FIRST_DEVICE_VECTOR ||
228  vector > IA64_LAST_DEVICE_VECTOR)
229  return;
230  clear_irq_vector(vector);
231 }
232 
233 int
234 reserve_irq_vector (int vector)
235 {
236  if (vector < IA64_FIRST_DEVICE_VECTOR ||
237  vector > IA64_LAST_DEVICE_VECTOR)
238  return -EINVAL;
239  return !!bind_irq_vector(vector, vector, CPU_MASK_ALL);
240 }
241 
242 /*
243  * Initialize vector_irq on a new cpu. This function must be called
244  * with vector_lock held.
245  */
246 void __setup_vector_irq(int cpu)
247 {
248  int irq, vector;
249 
250  /* Clear vector_irq */
251  for (vector = 0; vector < IA64_NUM_VECTORS; ++vector)
252  per_cpu(vector_irq, cpu)[vector] = -1;
253  /* Mark the inuse vectors */
254  for (irq = 0; irq < NR_IRQS; ++irq) {
255  if (!cpu_isset(cpu, irq_cfg[irq].domain))
256  continue;
257  vector = irq_to_vector(irq);
258  per_cpu(vector_irq, cpu)[vector] = irq;
259  }
260 }
261 
262 #if defined(CONFIG_SMP) && (defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_DIG))
263 
264 static enum vector_domain_type {
265  VECTOR_DOMAIN_NONE,
266  VECTOR_DOMAIN_PERCPU
267 } vector_domain_type = VECTOR_DOMAIN_NONE;
268 
269 static cpumask_t vector_allocation_domain(int cpu)
270 {
271  if (vector_domain_type == VECTOR_DOMAIN_PERCPU)
272  return cpumask_of_cpu(cpu);
273  return CPU_MASK_ALL;
274 }
275 
276 static int __irq_prepare_move(int irq, int cpu)
277 {
278  struct irq_cfg *cfg = &irq_cfg[irq];
279  int vector;
281 
282  if (cfg->move_in_progress || cfg->move_cleanup_count)
283  return -EBUSY;
284  if (cfg->vector == IRQ_VECTOR_UNASSIGNED || !cpu_online(cpu))
285  return -EINVAL;
286  if (cpu_isset(cpu, cfg->domain))
287  return 0;
288  domain = vector_allocation_domain(cpu);
289  vector = find_unassigned_vector(domain);
290  if (vector < 0)
291  return -ENOSPC;
292  cfg->move_in_progress = 1;
293  cfg->old_domain = cfg->domain;
295  cfg->domain = CPU_MASK_NONE;
296  BUG_ON(__bind_irq_vector(irq, vector, domain));
297  return 0;
298 }
299 
300 int irq_prepare_move(int irq, int cpu)
301 {
302  unsigned long flags;
303  int ret;
304 
305  spin_lock_irqsave(&vector_lock, flags);
306  ret = __irq_prepare_move(irq, cpu);
307  spin_unlock_irqrestore(&vector_lock, flags);
308  return ret;
309 }
310 
311 void irq_complete_move(unsigned irq)
312 {
313  struct irq_cfg *cfg = &irq_cfg[irq];
314  cpumask_t cleanup_mask;
315  int i;
316 
317  if (likely(!cfg->move_in_progress))
318  return;
319 
321  return;
322 
323  cpumask_and(&cleanup_mask, &cfg->old_domain, cpu_online_mask);
324  cfg->move_cleanup_count = cpus_weight(cleanup_mask);
325  for_each_cpu_mask(i, cleanup_mask)
326  platform_send_ipi(i, IA64_IRQ_MOVE_VECTOR, IA64_IPI_DM_INT, 0);
327  cfg->move_in_progress = 0;
328 }
329 
330 static irqreturn_t smp_irq_move_cleanup_interrupt(int irq, void *dev_id)
331 {
332  int me = smp_processor_id();
334  unsigned long flags;
335 
336  for (vector = IA64_FIRST_DEVICE_VECTOR;
337  vector < IA64_LAST_DEVICE_VECTOR; vector++) {
338  int irq;
339  struct irq_desc *desc;
340  struct irq_cfg *cfg;
341  irq = __get_cpu_var(vector_irq)[vector];
342  if (irq < 0)
343  continue;
344 
345  desc = irq_to_desc(irq);
346  cfg = irq_cfg + irq;
347  raw_spin_lock(&desc->lock);
348  if (!cfg->move_cleanup_count)
349  goto unlock;
350 
351  if (!cpu_isset(me, cfg->old_domain))
352  goto unlock;
353 
354  spin_lock_irqsave(&vector_lock, flags);
355  __get_cpu_var(vector_irq)[vector] = -1;
356  cpu_clear(me, vector_table[vector]);
357  spin_unlock_irqrestore(&vector_lock, flags);
358  cfg->move_cleanup_count--;
359  unlock:
360  raw_spin_unlock(&desc->lock);
361  }
362  return IRQ_HANDLED;
363 }
364 
365 static struct irqaction irq_move_irqaction = {
366  .handler = smp_irq_move_cleanup_interrupt,
367  .flags = IRQF_DISABLED,
368  .name = "irq_move"
369 };
370 
371 static int __init parse_vector_domain(char *arg)
372 {
373  if (!arg)
374  return -EINVAL;
375  if (!strcmp(arg, "percpu")) {
376  vector_domain_type = VECTOR_DOMAIN_PERCPU;
377  no_int_routing = 1;
378  }
379  return 0;
380 }
381 early_param("vector", parse_vector_domain);
382 #else
383 static cpumask_t vector_allocation_domain(int cpu)
384 {
385  return CPU_MASK_ALL;
386 }
387 #endif
388 
389 
390 void destroy_and_reserve_irq(unsigned int irq)
391 {
392  unsigned long flags;
393 
394  dynamic_irq_cleanup(irq);
395 
397  __clear_irq_vector(irq);
398  irq_status[irq] = IRQ_RSVD;
399  spin_unlock_irqrestore(&vector_lock, flags);
400 }
401 
402 /*
403  * Dynamic irq allocate and deallocation for MSI
404  */
405 int create_irq(void)
406 {
407  unsigned long flags;
408  int irq, vector, cpu;
409  cpumask_t domain = CPU_MASK_NONE;
410 
411  irq = vector = -ENOSPC;
413  for_each_online_cpu(cpu) {
414  domain = vector_allocation_domain(cpu);
415  vector = find_unassigned_vector(domain);
416  if (vector >= 0)
417  break;
418  }
419  if (vector < 0)
420  goto out;
421  irq = find_unassigned_irq();
422  if (irq < 0)
423  goto out;
424  BUG_ON(__bind_irq_vector(irq, vector, domain));
425  out:
426  spin_unlock_irqrestore(&vector_lock, flags);
427  if (irq >= 0)
428  dynamic_irq_init(irq);
429  return irq;
430 }
431 
432 void destroy_irq(unsigned int irq)
433 {
434  dynamic_irq_cleanup(irq);
435  clear_irq_vector(irq);
436 }
437 
438 #ifdef CONFIG_SMP
439 # define IS_RESCHEDULE(vec) (vec == IA64_IPI_RESCHEDULE)
440 # define IS_LOCAL_TLB_FLUSH(vec) (vec == IA64_IPI_LOCAL_TLB_FLUSH)
441 #else
442 # define IS_RESCHEDULE(vec) (0)
443 # define IS_LOCAL_TLB_FLUSH(vec) (0)
444 #endif
445 /*
446  * That's where the IVT branches when we get an external
447  * interrupt. This branches to the correct hardware IRQ handler via
448  * function ptr.
449  */
450 void
452 {
453  struct pt_regs *old_regs = set_irq_regs(regs);
454  unsigned long saved_tpr;
455 
456 #if IRQ_DEBUG
457  {
458  unsigned long bsp, sp;
459 
460  /*
461  * Note: if the interrupt happened while executing in
462  * the context switch routine (ia64_switch_to), we may
463  * get a spurious stack overflow here. This is
464  * because the register and the memory stack are not
465  * switched atomically.
466  */
469 
470  if ((sp - bsp) < 1024) {
471  static DEFINE_RATELIMIT_STATE(ratelimit, 5 * HZ, 5);
472 
473  if (__ratelimit(&ratelimit)) {
474  printk("ia64_handle_irq: DANGER: less than "
475  "1KB of free stack space!!\n"
476  "(bsp=0x%lx, sp=%lx)\n", bsp, sp);
477  }
478  }
479  }
480 #endif /* IRQ_DEBUG */
481 
482  /*
483  * Always set TPR to limit maximum interrupt nesting depth to
484  * 16 (without this, it would be ~240, which could easily lead
485  * to kernel stack overflows).
486  */
487  irq_enter();
488  saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
489  ia64_srlz_d();
490  while (vector != IA64_SPURIOUS_INT_VECTOR) {
491  int irq = local_vector_to_irq(vector);
492  struct irq_desc *desc = irq_to_desc(irq);
493 
494  if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
496  kstat_incr_irqs_this_cpu(irq, desc);
497  } else if (unlikely(IS_RESCHEDULE(vector))) {
498  scheduler_ipi();
499  kstat_incr_irqs_this_cpu(irq, desc);
500  } else {
501  ia64_setreg(_IA64_REG_CR_TPR, vector);
502  ia64_srlz_d();
503 
504  if (unlikely(irq < 0)) {
505  printk(KERN_ERR "%s: Unexpected interrupt "
506  "vector %d on CPU %d is not mapped "
507  "to any IRQ!\n", __func__, vector,
508  smp_processor_id());
509  } else
510  generic_handle_irq(irq);
511 
512  /*
513  * Disable interrupts and send EOI:
514  */
516  ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
517  }
518  ia64_eoi();
519  vector = ia64_get_ivr();
520  }
521  /*
522  * This must be done *after* the ia64_eoi(). For example, the keyboard softirq
523  * handler needs to be able to wait for further keyboard interrupts, which can't
524  * come through until ia64_eoi() has been done.
525  */
526  irq_exit();
527  set_irq_regs(old_regs);
528 }
529 
530 #ifdef CONFIG_HOTPLUG_CPU
531 /*
532  * This function emulates a interrupt processing when a cpu is about to be
533  * brought down.
534  */
535 void ia64_process_pending_intr(void)
536 {
538  unsigned long saved_tpr;
539  extern unsigned int vectors_in_migration[NR_IRQS];
540 
541  vector = ia64_get_ivr();
542 
543  irq_enter();
544  saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
545  ia64_srlz_d();
546 
547  /*
548  * Perform normal interrupt style processing
549  */
550  while (vector != IA64_SPURIOUS_INT_VECTOR) {
551  int irq = local_vector_to_irq(vector);
552  struct irq_desc *desc = irq_to_desc(irq);
553 
554  if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
556  kstat_incr_irqs_this_cpu(irq, desc);
557  } else if (unlikely(IS_RESCHEDULE(vector))) {
558  kstat_incr_irqs_this_cpu(irq, desc);
559  } else {
560  struct pt_regs *old_regs = set_irq_regs(NULL);
561 
562  ia64_setreg(_IA64_REG_CR_TPR, vector);
563  ia64_srlz_d();
564 
565  /*
566  * Now try calling normal ia64_handle_irq as it would have got called
567  * from a real intr handler. Try passing null for pt_regs, hopefully
568  * it will work. I hope it works!.
569  * Probably could shared code.
570  */
571  if (unlikely(irq < 0)) {
572  printk(KERN_ERR "%s: Unexpected interrupt "
573  "vector %d on CPU %d not being mapped "
574  "to any IRQ!!\n", __func__, vector,
575  smp_processor_id());
576  } else {
577  vectors_in_migration[irq]=0;
578  generic_handle_irq(irq);
579  }
580  set_irq_regs(old_regs);
581 
582  /*
583  * Disable interrupts and send EOI
584  */
586  ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
587  }
588  ia64_eoi();
589  vector = ia64_get_ivr();
590  }
591  irq_exit();
592 }
593 #endif
594 
595 
596 #ifdef CONFIG_SMP
597 
598 static irqreturn_t dummy_handler (int irq, void *dev_id)
599 {
600  BUG();
601 }
602 
603 static struct irqaction ipi_irqaction = {
604  .handler = handle_IPI,
605  .flags = IRQF_DISABLED,
606  .name = "IPI"
607 };
608 
609 /*
610  * KVM uses this interrupt to force a cpu out of guest mode
611  */
612 static struct irqaction resched_irqaction = {
614  .flags = IRQF_DISABLED,
615  .name = "resched"
616 };
617 
618 static struct irqaction tlb_irqaction = {
620  .flags = IRQF_DISABLED,
621  .name = "tlb_flush"
622 };
623 
624 #endif
625 
626 void
628 {
629  unsigned int irq;
630 
631  irq = vec;
632  BUG_ON(bind_irq_vector(irq, vec, CPU_MASK_ALL));
633  irq_set_status_flags(irq, IRQ_PER_CPU);
635  if (action)
636  setup_irq(irq, action);
637  irq_set_handler(irq, handle_percpu_irq);
638 }
639 
640 void __init
642 {
643 #ifdef CONFIG_SMP
644  register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction);
645  register_percpu_irq(IA64_IPI_RESCHEDULE, &resched_irqaction);
647 #endif
648 }
649 
650 void __init
651 init_IRQ (void)
652 {
653 #ifdef CONFIG_ACPI
654  acpi_boot_init();
655 #endif
658 #ifdef CONFIG_SMP
659 #if defined(CONFIG_IA64_GENERIC) || defined(CONFIG_IA64_DIG)
660  if (vector_domain_type != VECTOR_DOMAIN_NONE)
661  register_percpu_irq(IA64_IRQ_MOVE_VECTOR, &irq_move_irqaction);
662 #endif
663 #endif
664 #ifdef CONFIG_PERFMON
665  pfm_init_percpu();
666 #endif
668 }
669 
670 void
671 ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
672 {
673  void __iomem *ipi_addr;
674  unsigned long ipi_data;
675  unsigned long phys_cpu_id;
676 
677  phys_cpu_id = cpu_physical_id(cpu);
678 
679  /*
680  * cpu number is in 8bit ID and 8bit EID
681  */
682 
683  ipi_data = (delivery_mode << 8) | (vector & 0xff);
684  ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));
685 
686  writeq(ipi_data, ipi_addr);
687 }