arch/powerpc/kernel/irq.c

   1 /*
   2  *  Derived from arch/i386/kernel/irq.c
   3  *    Copyright (C) 1992 Linus Torvalds
   4  *  Adapted from arch/i386 by Gary Thomas
   5  *    Copyright (C) 1995-1996 Gary Thomas (gdt@linuxppc.org)
   6  *  Updated and modified by Cort Dougan <cort@fsmlabs.com>
   7  *    Copyright (C) 1996-2001 Cort Dougan
   8  *  Adapted for Power Macintosh by Paul Mackerras
   9  *    Copyright (C) 1996 Paul Mackerras (paulus@cs.anu.edu.au)
  10  *  Amiga/APUS changes by Jesper Skov (jskov@cygnus.co.uk).
  11  *
  12  * This program is free software; you can redistribute it and/or
  13  * modify it under the terms of the GNU General Public License
  14  * as published by the Free Software Foundation; either version
  15  * 2 of the License, or (at your option) any later version.
  16  *
  17  * This file contains the code used by various IRQ handling routines:
  18  * asking for different IRQ's should be done through these routines
  19  * instead of just grabbing them. Thus setups with different IRQ numbers
  20  * shouldn't result in any weird surprises, and installing new handlers
  21  * should be easier.
  22  *
  23  * The MPC8xx has an interrupt mask in the SIU.  If a bit is set, the
  24  * interrupt is _enabled_.  As expected, IRQ0 is bit 0 in the 32-bit
  25  * mask register (of which only 16 are defined), hence the weird shifting
  26  * and complement of the cached_irq_mask.  I want to be able to stuff
  27  * this right into the SIU SMASK register.
  28  * Many of the prep/chrp functions are conditional compiled on CONFIG_8xx
  29  * to reduce code space and undefined function references.
  30  */
  31
  32 #include <linux/module.h>
  33 #include <linux/threads.h>
  34 #include <linux/kernel_stat.h>
  35 #include <linux/signal.h>
  36 #include <linux/sched.h>
  37 #include <linux/ptrace.h>
  38 #include <linux/ioport.h>
  39 #include <linux/interrupt.h>
  40 #include <linux/timex.h>
  41 #include <linux/init.h>
  42 #include <linux/slab.h>
  43 #include <linux/delay.h>
  44 #include <linux/irq.h>
  45 #include <linux/seq_file.h>
  46 #include <linux/cpumask.h>
  47 #include <linux/profile.h>
  48 #include <linux/bitops.h>
  49 #include <linux/pci.h>
  50
  51 #include <asm/uaccess.h>
  52 #include <asm/system.h>
  53 #include <asm/io.h>
  54 #include <asm/pgtable.h>
  55 #include <asm/irq.h>
  56 #include <asm/cache.h>
  57 #include <asm/prom.h>
  58 #include <asm/ptrace.h>
  59 #include <asm/machdep.h>
  60 #ifdef CONFIG_PPC_ISERIES
  61 #include <asm/paca.h>
  62 #endif
  63
  64 int __irq_offset_value;
  65 #ifdef CONFIG_PPC32
  66 EXPORT_SYMBOL(__irq_offset_value);
  67 #endif
  68
  69 static int ppc_spurious_interrupts;
  70
  71 #ifdef CONFIG_PPC32
  72 #define NR_MASK_WORDS   ((NR_IRQS + 31) / 32)
  73
  74 unsigned long ppc_cached_irq_mask[NR_MASK_WORDS];
  75 atomic_t ppc_n_lost_interrupts;
  76
  77 #ifdef CONFIG_TAU_INT
  78 extern int tau_initialized;
  79 extern int tau_interrupts(int);
  80 #endif
  81
  82 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
  83 extern atomic_t ipi_recv;
  84 extern atomic_t ipi_sent;
  85 #endif
  86 #endif /* CONFIG_PPC32 */
  87
  88 #ifdef CONFIG_PPC64
  89 EXPORT_SYMBOL(irq_desc);
  90
  91 int distribute_irqs = 1;
  92 u64 ppc64_interrupt_controller;
  93 #endif /* CONFIG_PPC64 */
  94
  95 int show_interrupts(struct seq_file *p, void *v)
  96 {
  97         int i = *(loff_t *)v, j;
  98         struct irqaction *action;
  99         irq_desc_t *desc;
 100         unsigned long flags;
 101
 102         if (i == 0) {
 103                 seq_puts(p, "           ");
 104                 for_each_online_cpu(j)
 105                         seq_printf(p, "CPU%d       ", j);
 106                 seq_putc(p, '\n');
 107         }
 108
 109         if (i < NR_IRQS) {
 110                 desc = get_irq_desc(i);
 111                 spin_lock_irqsave(&desc->lock, flags);
 112                 action = desc->action;
 113                 if (!action || !action->handler)
 114                         goto skip;
 115                 seq_printf(p, "%3d: ", i);
 116 #ifdef CONFIG_SMP
 117                 for_each_online_cpu(j)
 118                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
 119 #else
 120                 seq_printf(p, "%10u ", kstat_irqs(i));
 121 #endif /* CONFIG_SMP */
 122                 if (desc->chip)
 123                         seq_printf(p, " %s ", desc->chip->typename);
 124                 else
 125                         seq_puts(p, "  None      ");
 126                 seq_printf(p, "%s", (desc->status & IRQ_LEVEL) ? "Level " : "Edge  ");
 127                 seq_printf(p, "    %s", action->name);
 128                 for (action = action->next; action; action = action->next)
 129                         seq_printf(p, ", %s", action->name);
 130                 seq_putc(p, '\n');
 131 skip:
 132                 spin_unlock_irqrestore(&desc->lock, flags);
 133         } else if (i == NR_IRQS) {
 134 #ifdef CONFIG_PPC32
 135 #ifdef CONFIG_TAU_INT
 136                 if (tau_initialized){
 137                         seq_puts(p, "TAU: ");
 138                         for_each_online_cpu(j)
 139                                 seq_printf(p, "%10u ", tau_interrupts(j));
 140                         seq_puts(p, "  PowerPC             Thermal Assist (cpu temp)\n");
 141                 }
 142 #endif
 143 #if defined(CONFIG_SMP) && !defined(CONFIG_PPC_MERGE)
 144                 /* should this be per processor send/receive? */
 145                 seq_printf(p, "IPI (recv/sent): %10u/%u\n",
 146                                 atomic_read(&ipi_recv), atomic_read(&ipi_sent));
 147 #endif
 148 #endif /* CONFIG_PPC32 */
 149                 seq_printf(p, "BAD: %10u\n", ppc_spurious_interrupts);
 150         }
 151         return 0;
 152 }
 153
 154 #ifdef CONFIG_HOTPLUG_CPU
 155 void fixup_irqs(cpumask_t map)
 156 {
 157         unsigned int irq;
 158         static int warned;
 159
 160         for_each_irq(irq) {
 161                 cpumask_t mask;
 162
 163                 if (irq_desc[irq].status & IRQ_PER_CPU)
 164                         continue;
 165
 166                 cpus_and(mask, irq_desc[irq].affinity, map);
 167                 if (any_online_cpu(mask) == NR_CPUS) {
 168                         printk("Breaking affinity for irq %i\n", irq);
 169                         mask = map;
 170                 }
 171                 if (irq_desc[irq].chip->set_affinity)
 172                         irq_desc[irq].chip->set_affinity(irq, mask);
 173                 else if (irq_desc[irq].action && !(warned++))
 174                         printk("Cannot set affinity for irq %i\n", irq);
 175         }
 176
 177         local_irq_enable();
 178         mdelay(1);
 179         local_irq_disable();
 180 }
 181 #endif
 182
 183 void do_IRQ(struct pt_regs *regs)
 184 {
 185         int irq;
 186 #ifdef CONFIG_IRQSTACKS
 187         struct thread_info *curtp, *irqtp;
 188 #endif
 189
 190         irq_enter();
 191
 192 #ifdef CONFIG_DEBUG_STACKOVERFLOW
 193         /* Debugging check for stack overflow: is there less than 2KB free? */
 194         {
 195                 long sp;
 196
 197                 sp = __get_SP() & (THREAD_SIZE-1);
 198
 199                 if (unlikely(sp < (sizeof(struct thread_info) + 2048))) {
 200                         printk("do_IRQ: stack overflow: %ld\n",
 201                                 sp - sizeof(struct thread_info));
 202                         dump_stack();
 203                 }
 204         }
 205 #endif
 206
 207         /*
 208          * Every platform is required to implement ppc_md.get_irq.
 209          * This function will either return an irq number or -1 to
 210          * indicate there are no more pending.
 211          * The value -2 is for buggy hardware and means that this IRQ
 212          * has already been handled. -- Tom
 213          */
 214         irq = ppc_md.get_irq(regs);
 215
 216         if (irq >= 0) {
 217 #ifdef CONFIG_IRQSTACKS
 218                 /* Switch to the irq stack to handle this */
 219                 curtp = current_thread_info();
 220                 irqtp = hardirq_ctx[smp_processor_id()];
 221                 if (curtp != irqtp) {
 222                         irqtp->task = curtp->task;
 223                         irqtp->flags = 0;
 224                         call___do_IRQ(irq, regs, irqtp);
 225                         irqtp->task = NULL;
 226                         if (irqtp->flags)
 227                                 set_bits(irqtp->flags, &curtp->flags);
 228                 } else
 229 #endif
 230                         __do_IRQ(irq, regs);
 231         } else if (irq != -2)
 232                 /* That's not SMP safe ... but who cares ? */
 233                 ppc_spurious_interrupts++;
 234
 235         irq_exit();
 236
 237 #ifdef CONFIG_PPC_ISERIES
 238         if (get_lppaca()->int_dword.fields.decr_int) {
 239                 get_lppaca()->int_dword.fields.decr_int = 0;
 240                 /* Signal a fake decrementer interrupt */
 241                 timer_interrupt(regs);
 242         }
 243 #endif
 244 }
 245
 246 void __init init_IRQ(void)
 247 {
 248 #ifdef CONFIG_PPC64
 249         static int once = 0;
 250
 251         if (once)
 252                 return;
 253
 254         once++;
 255
 256 #endif
 257         ppc_md.init_IRQ();
 258 #ifdef CONFIG_PPC64
 259         irq_ctx_init();
 260 #endif
 261 }
 262
 263 #ifdef CONFIG_PPC64
 264 /*
 265  * Virtual IRQ mapping code, used on systems with XICS interrupt controllers.
 266  */
 267
 268 #define UNDEFINED_IRQ 0xffffffff
 269 unsigned int virt_irq_to_real_map[NR_IRQS];
 270
 271 /*
 272  * Don't use virtual irqs 0, 1, 2 for devices.
 273  * The pcnet32 driver considers interrupt numbers < 2 to be invalid,
 274  * and 2 is the XICS IPI interrupt.
 275  * We limit virtual irqs to __irq_offet_value less than virt_irq_max so
 276  * that when we offset them we don't end up with an interrupt
 277  * number >= virt_irq_max.
 278  */
 279 #define MIN_VIRT_IRQ    3
 280
 281 unsigned int virt_irq_max;
 282 static unsigned int max_virt_irq;
 283 static unsigned int nr_virt_irqs;
 284
 285 void
 286 virt_irq_init(void)
 287 {
 288         int i;
 289
 290         if ((virt_irq_max == 0) || (virt_irq_max > (NR_IRQS - 1)))
 291                 virt_irq_max = NR_IRQS - 1;
 292         max_virt_irq = virt_irq_max - __irq_offset_value;
 293         nr_virt_irqs = max_virt_irq - MIN_VIRT_IRQ + 1;
 294
 295         for (i = 0; i < NR_IRQS; i++)
 296                 virt_irq_to_real_map[i] = UNDEFINED_IRQ;
 297 }
 298
 299 /* Create a mapping for a real_irq if it doesn't already exist.
 300  * Return the virtual irq as a convenience.
 301  */
 302 int virt_irq_create_mapping(unsigned int real_irq)
 303 {
 304         unsigned int virq, first_virq;
 305         static int warned;
 306
 307         if (ppc64_interrupt_controller == IC_OPEN_PIC)
 308                 return real_irq;        /* no mapping for openpic (for now) */
 309
 310         if (ppc64_interrupt_controller == IC_CELL_PIC)
 311                 return real_irq;        /* no mapping for iic either */
 312
 313         /* don't map interrupts < MIN_VIRT_IRQ */
 314         if (real_irq < MIN_VIRT_IRQ) {
 315                 virt_irq_to_real_map[real_irq] = real_irq;
 316                 return real_irq;
 317         }
 318
 319         /* map to a number between MIN_VIRT_IRQ and max_virt_irq */
 320         virq = real_irq;
 321         if (virq > max_virt_irq)
 322                 virq = (virq % nr_virt_irqs) + MIN_VIRT_IRQ;
 323
 324         /* search for this number or a free slot */
 325         first_virq = virq;
 326         while (virt_irq_to_real_map[virq] != UNDEFINED_IRQ) {
 327                 if (virt_irq_to_real_map[virq] == real_irq)
 328                         return virq;
 329                 if (++virq > max_virt_irq)
 330                         virq = MIN_VIRT_IRQ;
 331                 if (virq == first_virq)
 332                         goto nospace;   /* oops, no free slots */
 333         }
 334
 335         virt_irq_to_real_map[virq] = real_irq;
 336         return virq;
 337
 338  nospace:
 339         if (!warned) {
 340                 printk(KERN_CRIT "Interrupt table is full\n");
 341                 printk(KERN_CRIT "Increase virt_irq_max (currently %d) "
 342                        "in your kernel sources and rebuild.\n", virt_irq_max);
 343                 warned = 1;
 344         }
 345         return NO_IRQ;
 346 }
 347
 348 /*
 349  * In most cases will get a hit on the very first slot checked in the
 350  * virt_irq_to_real_map.  Only when there are a large number of
 351  * IRQs will this be expensive.
 352  */
 353 unsigned int real_irq_to_virt_slowpath(unsigned int real_irq)
 354 {
 355         unsigned int virq;
 356         unsigned int first_virq;
 357
 358         virq = real_irq;
 359
 360         if (virq > max_virt_irq)
 361                 virq = (virq % nr_virt_irqs) + MIN_VIRT_IRQ;
 362
 363         first_virq = virq;
 364
 365         do {
 366                 if (virt_irq_to_real_map[virq] == real_irq)
 367                         return virq;
 368
 369                 virq++;
 370
 371                 if (virq >= max_virt_irq)
 372                         virq = 0;
 373
 374         } while (first_virq != virq);
 375
 376         return NO_IRQ;
 377
 378 }
 379 #endif /* CONFIG_PPC64 */
 380
 381 #ifdef CONFIG_IRQSTACKS
 382 struct thread_info *softirq_ctx[NR_CPUS] __read_mostly;
 383 struct thread_info *hardirq_ctx[NR_CPUS] __read_mostly;
 384
 385 void irq_ctx_init(void)
 386 {
 387         struct thread_info *tp;
 388         int i;
 389
 390         for_each_possible_cpu(i) {
 391                 memset((void *)softirq_ctx[i], 0, THREAD_SIZE);
 392                 tp = softirq_ctx[i];
 393                 tp->cpu = i;
 394                 tp->preempt_count = SOFTIRQ_OFFSET;
 395
 396                 memset((void *)hardirq_ctx[i], 0, THREAD_SIZE);
 397                 tp = hardirq_ctx[i];
 398                 tp->cpu = i;
 399                 tp->preempt_count = HARDIRQ_OFFSET;
 400         }
 401 }
 402
 403 static inline void do_softirq_onstack(void)
 404 {
 405         struct thread_info *curtp, *irqtp;
 406
 407         curtp = current_thread_info();
 408         irqtp = softirq_ctx[smp_processor_id()];
 409         irqtp->task = curtp->task;
 410         call_do_softirq(irqtp);
 411         irqtp->task = NULL;
 412 }
 413
 414 #else
 415 #define do_softirq_onstack()    __do_softirq()
 416 #endif /* CONFIG_IRQSTACKS */
 417
 418 void do_softirq(void)
 419 {
 420         unsigned long flags;
 421
 422         if (in_interrupt())
 423                 return;
 424
 425         local_irq_save(flags);
 426
 427         if (local_softirq_pending()) {
 428                 account_system_vtime(current);
 429                 local_bh_disable();
 430                 do_softirq_onstack();
 431                 account_system_vtime(current);
 432                 _local_bh_enable();
 433         }
 434
 435         local_irq_restore(flags);
 436 }
 437 EXPORT_SYMBOL(do_softirq);
 438
 439 #ifdef CONFIG_PCI_MSI
 440 int pci_enable_msi(struct pci_dev * pdev)
 441 {
 442         if (ppc_md.enable_msi)
 443                 return ppc_md.enable_msi(pdev);
 444         else
 445                 return -1;
 446 }
 447
 448 void pci_disable_msi(struct pci_dev * pdev)
 449 {
 450         if (ppc_md.disable_msi)
 451                 ppc_md.disable_msi(pdev);
 452 }
 453
 454 void pci_scan_msi_device(struct pci_dev *dev) {}
 455 int pci_enable_msix(struct pci_dev* dev, struct msix_entry *entries, int nvec) {return -1;}
 456 void pci_disable_msix(struct pci_dev *dev) {}
 457 void msi_remove_pci_irq_vectors(struct pci_dev *dev) {}
 458 void disable_msi_mode(struct pci_dev *dev, int pos, int type) {}
 459 void pci_no_msi(void) {}
 460
 461 #endif
 462
 463 #ifdef CONFIG_PPC64
 464 static int __init setup_noirqdistrib(char *str)
 465 {
 466         distribute_irqs = 0;
 467         return 1;
 468 }
 469
 470 __setup("noirqdistrib", setup_noirqdistrib);
 471 #endif /* CONFIG_PPC64 */