arch/ia64/kernel/irq_ia64.c

   1 /*
   2  * linux/arch/ia64/kernel/irq_ia64.c
   3  *
   4  * Copyright (C) 1998-2001 Hewlett-Packard Co
   5  *      Stephane Eranian <eranian@hpl.hp.com>
   6  *      David Mosberger-Tang <davidm@hpl.hp.com>
   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 <goutham.rao@intel.com> Implemented pci_irq_to_vector
  12  *                      PCI to vector allocation routine.
  13  * 04/14/2004 Ashok Raj <ashok.raj@intel.com>
  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/slab.h>
  26 #include <linux/ptrace.h>
  27 #include <linux/random.h>       /* for rand_initialize_irq() */
  28 #include <linux/signal.h>
  29 #include <linux/smp.h>
  30 #include <linux/threads.h>
  31 #include <linux/bitops.h>
  32 #include <linux/irq.h>
  33
  34 #include <asm/delay.h>
  35 #include <asm/intrinsics.h>
  36 #include <asm/io.h>
  37 #include <asm/hw_irq.h>
  38 #include <asm/machvec.h>
  39 #include <asm/pgtable.h>
  40 #include <asm/system.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 */
  56 int ia64_first_device_vector = IA64_DEF_FIRST_DEVICE_VECTOR;
  57 int ia64_last_device_vector = IA64_DEF_LAST_DEVICE_VECTOR;
  58
  59 /* default base addr of IPI table */
  60 void __iomem *ipi_base_addr = ((void __iomem *)
  61                                (__IA64_UNCACHED_OFFSET | IA64_IPI_DEFAULT_BASE_ADDR));
  62
  63 /*
  64  * Legacy IRQ to IA-64 vector translation table.
  65  */
  66 __u8 isa_irq_to_vector_map[16] = {
  67         /* 8259 IRQ translation, first 16 entries */
  68         0x2f, 0x20, 0x2e, 0x2d, 0x2c, 0x2b, 0x2a, 0x29,
  69         0x28, 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21
  70 };
  71 EXPORT_SYMBOL(isa_irq_to_vector_map);
  72
  73 DEFINE_SPINLOCK(vector_lock);
  74
  75 struct irq_cfg irq_cfg[NR_IRQS] __read_mostly = {
  76         [0 ... NR_IRQS - 1] = { .vector = IRQ_VECTOR_UNASSIGNED }
  77 };
  78
  79 DEFINE_PER_CPU(int[IA64_NUM_VECTORS], vector_irq) = {
  80         [0 ... IA64_NUM_VECTORS - 1] = IA64_SPURIOUS_INT_VECTOR
  81 };
  82
  83 static int irq_status[NR_IRQS] = {
  84         [0 ... NR_IRQS -1] = IRQ_UNUSED
  85 };
  86
  87 int check_irq_used(int irq)
  88 {
  89         if (irq_status[irq] == IRQ_USED)
  90                 return 1;
  91
  92         return -1;
  93 }
  94
  95 static void reserve_irq(unsigned int irq)
  96 {
  97         unsigned long flags;
  98
  99         spin_lock_irqsave(&vector_lock, flags);
 100         irq_status[irq] = IRQ_RSVD;
 101         spin_unlock_irqrestore(&vector_lock, flags);
 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(void)
 115 {
 116         int vector;
 117
 118         for (vector = IA64_FIRST_DEVICE_VECTOR;
 119              vector <= IA64_LAST_DEVICE_VECTOR; vector++)
 120                 if (__get_cpu_var(vector_irq[vector]) == IA64_SPURIOUS_INT_VECTOR)
 121                         return vector;
 122         return -ENOSPC;
 123 }
 124
 125 static int __bind_irq_vector(int irq, int vector)
 126 {
 127         int cpu;
 128
 129         if (irq_to_vector(irq) == vector)
 130                 return 0;
 131         if (irq_to_vector(irq) != IRQ_VECTOR_UNASSIGNED)
 132                 return -EBUSY;
 133         for_each_online_cpu(cpu)
 134                 per_cpu(vector_irq, cpu)[vector] = irq;
 135         irq_cfg[irq].vector = vector;
 136         irq_status[irq] = IRQ_USED;
 137         return 0;
 138 }
 139
 140 int bind_irq_vector(int irq, int vector)
 141 {
 142         unsigned long flags;
 143         int ret;
 144
 145         spin_lock_irqsave(&vector_lock, flags);
 146         ret = __bind_irq_vector(irq, vector);
 147         spin_unlock_irqrestore(&vector_lock, flags);
 148         return ret;
 149 }
 150
 151 static void clear_irq_vector(int irq)
 152 {
 153         unsigned long flags;
 154         int vector, cpu;
 155
 156         spin_lock_irqsave(&vector_lock, flags);
 157         BUG_ON((unsigned)irq >= NR_IRQS);
 158         BUG_ON(irq_cfg[irq].vector == IRQ_VECTOR_UNASSIGNED);
 159         vector = irq_cfg[irq].vector;
 160         for_each_online_cpu(cpu)
 161                 per_cpu(vector_irq, cpu)[vector] = IA64_SPURIOUS_INT_VECTOR;
 162         irq_cfg[irq].vector = IRQ_VECTOR_UNASSIGNED;
 163         irq_status[irq] = IRQ_UNUSED;
 164         spin_unlock_irqrestore(&vector_lock, flags);
 165 }
 166
 167 int
 168 assign_irq_vector (int irq)
 169 {
 170         unsigned long flags;
 171         int vector = -ENOSPC;
 172
 173         if (irq < 0) {
 174                 goto out;
 175         }
 176         spin_lock_irqsave(&vector_lock, flags);
 177         vector = find_unassigned_vector();
 178         if (vector < 0)
 179                 goto out;
 180         BUG_ON(__bind_irq_vector(irq, vector));
 181         spin_unlock_irqrestore(&vector_lock, flags);
 182  out:
 183         return vector;
 184 }
 185
 186 void
 187 free_irq_vector (int vector)
 188 {
 189         if (vector < IA64_FIRST_DEVICE_VECTOR ||
 190             vector > IA64_LAST_DEVICE_VECTOR)
 191                 return;
 192         clear_irq_vector(vector);
 193 }
 194
 195 int
 196 reserve_irq_vector (int vector)
 197 {
 198         if (vector < IA64_FIRST_DEVICE_VECTOR ||
 199             vector > IA64_LAST_DEVICE_VECTOR)
 200                 return -EINVAL;
 201         return !!bind_irq_vector(vector, vector);
 202 }
 203
 204 /*
 205  * Initialize vector_irq on a new cpu. This function must be called
 206  * with vector_lock held.
 207  */
 208 void __setup_vector_irq(int cpu)
 209 {
 210         int irq, vector;
 211
 212         /* Clear vector_irq */
 213         for (vector = 0; vector < IA64_NUM_VECTORS; ++vector)
 214                 per_cpu(vector_irq, cpu)[vector] = IA64_SPURIOUS_INT_VECTOR;
 215         /* Mark the inuse vectors */
 216         for (irq = 0; irq < NR_IRQS; ++irq) {
 217                 if ((vector = irq_to_vector(irq)) != IRQ_VECTOR_UNASSIGNED)
 218                         per_cpu(vector_irq, cpu)[vector] = irq;
 219         }
 220 }
 221
 222 void destroy_and_reserve_irq(unsigned int irq)
 223 {
 224         dynamic_irq_cleanup(irq);
 225
 226         clear_irq_vector(irq);
 227         reserve_irq(irq);
 228 }
 229
 230 /*
 231  * Dynamic irq allocate and deallocation for MSI
 232  */
 233 int create_irq(void)
 234 {
 235         unsigned long flags;
 236         int irq, vector;
 237
 238         irq = -ENOSPC;
 239         spin_lock_irqsave(&vector_lock, flags);
 240         vector = find_unassigned_vector();
 241         if (vector < 0)
 242                 goto out;
 243         irq = find_unassigned_irq();
 244         if (irq < 0)
 245                 goto out;
 246         BUG_ON(__bind_irq_vector(irq, vector));
 247  out:
 248         spin_unlock_irqrestore(&vector_lock, flags);
 249         if (irq >= 0)
 250                 dynamic_irq_init(irq);
 251         return irq;
 252 }
 253
 254 void destroy_irq(unsigned int irq)
 255 {
 256         dynamic_irq_cleanup(irq);
 257         clear_irq_vector(irq);
 258 }
 259
 260 #ifdef CONFIG_SMP
 261 #       define IS_RESCHEDULE(vec)       (vec == IA64_IPI_RESCHEDULE)
 262 #       define IS_LOCAL_TLB_FLUSH(vec)  (vec == IA64_IPI_LOCAL_TLB_FLUSH)
 263 #else
 264 #       define IS_RESCHEDULE(vec)       (0)
 265 #       define IS_LOCAL_TLB_FLUSH(vec)  (0)
 266 #endif
 267 /*
 268  * That's where the IVT branches when we get an external
 269  * interrupt. This branches to the correct hardware IRQ handler via
 270  * function ptr.
 271  */
 272 void
 273 ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
 274 {
 275         struct pt_regs *old_regs = set_irq_regs(regs);
 276         unsigned long saved_tpr;
 277
 278 #if IRQ_DEBUG
 279         {
 280                 unsigned long bsp, sp;
 281
 282                 /*
 283                  * Note: if the interrupt happened while executing in
 284                  * the context switch routine (ia64_switch_to), we may
 285                  * get a spurious stack overflow here.  This is
 286                  * because the register and the memory stack are not
 287                  * switched atomically.
 288                  */
 289                 bsp = ia64_getreg(_IA64_REG_AR_BSP);
 290                 sp = ia64_getreg(_IA64_REG_SP);
 291
 292                 if ((sp - bsp) < 1024) {
 293                         static unsigned char count;
 294                         static long last_time;
 295
 296                         if (jiffies - last_time > 5*HZ)
 297                                 count = 0;
 298                         if (++count < 5) {
 299                                 last_time = jiffies;
 300                                 printk("ia64_handle_irq: DANGER: less than "
 301                                        "1KB of free stack space!!\n"
 302                                        "(bsp=0x%lx, sp=%lx)\n", bsp, sp);
 303                         }
 304                 }
 305         }
 306 #endif /* IRQ_DEBUG */
 307
 308         /*
 309          * Always set TPR to limit maximum interrupt nesting depth to
 310          * 16 (without this, it would be ~240, which could easily lead
 311          * to kernel stack overflows).
 312          */
 313         irq_enter();
 314         saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
 315         ia64_srlz_d();
 316         while (vector != IA64_SPURIOUS_INT_VECTOR) {
 317                 if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
 318                         smp_local_flush_tlb();
 319                         kstat_this_cpu.irqs[vector]++;
 320                 } else if (unlikely(IS_RESCHEDULE(vector)))
 321                         kstat_this_cpu.irqs[vector]++;
 322                 else {
 323                         ia64_setreg(_IA64_REG_CR_TPR, vector);
 324                         ia64_srlz_d();
 325
 326                         generic_handle_irq(local_vector_to_irq(vector));
 327
 328                         /*
 329                          * Disable interrupts and send EOI:
 330                          */
 331                         local_irq_disable();
 332                         ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
 333                 }
 334                 ia64_eoi();
 335                 vector = ia64_get_ivr();
 336         }
 337         /*
 338          * This must be done *after* the ia64_eoi().  For example, the keyboard softirq
 339          * handler needs to be able to wait for further keyboard interrupts, which can't
 340          * come through until ia64_eoi() has been done.
 341          */
 342         irq_exit();
 343         set_irq_regs(old_regs);
 344 }
 345
 346 #ifdef CONFIG_HOTPLUG_CPU
 347 /*
 348  * This function emulates a interrupt processing when a cpu is about to be
 349  * brought down.
 350  */
 351 void ia64_process_pending_intr(void)
 352 {
 353         ia64_vector vector;
 354         unsigned long saved_tpr;
 355         extern unsigned int vectors_in_migration[NR_IRQS];
 356
 357         vector = ia64_get_ivr();
 358
 359          irq_enter();
 360          saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
 361          ia64_srlz_d();
 362
 363          /*
 364           * Perform normal interrupt style processing
 365           */
 366         while (vector != IA64_SPURIOUS_INT_VECTOR) {
 367                 if (unlikely(IS_LOCAL_TLB_FLUSH(vector))) {
 368                         smp_local_flush_tlb();
 369                         kstat_this_cpu.irqs[vector]++;
 370                 } else if (unlikely(IS_RESCHEDULE(vector)))
 371                         kstat_this_cpu.irqs[vector]++;
 372                 else {
 373                         struct pt_regs *old_regs = set_irq_regs(NULL);
 374
 375                         ia64_setreg(_IA64_REG_CR_TPR, vector);
 376                         ia64_srlz_d();
 377
 378                         /*
 379                          * Now try calling normal ia64_handle_irq as it would have got called
 380                          * from a real intr handler. Try passing null for pt_regs, hopefully
 381                          * it will work. I hope it works!.
 382                          * Probably could shared code.
 383                          */
 384                         vectors_in_migration[local_vector_to_irq(vector)]=0;
 385                         generic_handle_irq(local_vector_to_irq(vector));
 386                         set_irq_regs(old_regs);
 387
 388                         /*
 389                          * Disable interrupts and send EOI
 390                          */
 391                         local_irq_disable();
 392                         ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
 393                 }
 394                 ia64_eoi();
 395                 vector = ia64_get_ivr();
 396         }
 397         irq_exit();
 398 }
 399 #endif
 400
 401
 402 #ifdef CONFIG_SMP
 403
 404 static irqreturn_t dummy_handler (int irq, void *dev_id)
 405 {
 406         BUG();
 407 }
 408 extern irqreturn_t handle_IPI (int irq, void *dev_id);
 409
 410 static struct irqaction ipi_irqaction = {
 411         .handler =      handle_IPI,
 412         .flags =        IRQF_DISABLED,
 413         .name =         "IPI"
 414 };
 415
 416 static struct irqaction resched_irqaction = {
 417         .handler =      dummy_handler,
 418         .flags =        IRQF_DISABLED,
 419         .name =         "resched"
 420 };
 421
 422 static struct irqaction tlb_irqaction = {
 423         .handler =      dummy_handler,
 424         .flags =        IRQF_DISABLED,
 425         .name =         "tlb_flush"
 426 };
 427
 428 #endif
 429
 430 void
 431 register_percpu_irq (ia64_vector vec, struct irqaction *action)
 432 {
 433         irq_desc_t *desc;
 434         unsigned int irq;
 435
 436         irq = vec;
 437         BUG_ON(bind_irq_vector(irq, vec));
 438         desc = irq_desc + irq;
 439         desc->status |= IRQ_PER_CPU;
 440         desc->chip = &irq_type_ia64_lsapic;
 441         if (action)
 442                 setup_irq(irq, action);
 443 }
 444
 445 void __init
 446 init_IRQ (void)
 447 {
 448         register_percpu_irq(IA64_SPURIOUS_INT_VECTOR, NULL);
 449 #ifdef CONFIG_SMP
 450         register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction);
 451         register_percpu_irq(IA64_IPI_RESCHEDULE, &resched_irqaction);
 452         register_percpu_irq(IA64_IPI_LOCAL_TLB_FLUSH, &tlb_irqaction);
 453 #endif
 454 #ifdef CONFIG_PERFMON
 455         pfm_init_percpu();
 456 #endif
 457         platform_irq_init();
 458 }
 459
 460 void
 461 ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
 462 {
 463         void __iomem *ipi_addr;
 464         unsigned long ipi_data;
 465         unsigned long phys_cpu_id;
 466
 467 #ifdef CONFIG_SMP
 468         phys_cpu_id = cpu_physical_id(cpu);
 469 #else
 470         phys_cpu_id = (ia64_getreg(_IA64_REG_CR_LID) >> 16) & 0xffff;
 471 #endif
 472
 473         /*
 474          * cpu number is in 8bit ID and 8bit EID
 475          */
 476
 477         ipi_data = (delivery_mode << 8) | (vector & 0xff);
 478         ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));
 479
 480         writeq(ipi_data, ipi_addr);
 481 }