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/smp_lock.h>
  31 #include <linux/threads.h>
  32 #include <linux/bitops.h>
  33 #include <linux/irq.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/system.h>
  42
  43 #ifdef CONFIG_PERFMON
  44 # include <asm/perfmon.h>
  45 #endif
  46
  47 #define IRQ_DEBUG       0
  48
  49 /* These can be overridden in platform_irq_init */
  50 int ia64_first_device_vector = IA64_DEF_FIRST_DEVICE_VECTOR;
  51 int ia64_last_device_vector = IA64_DEF_LAST_DEVICE_VECTOR;
  52
  53 /* default base addr of IPI table */
  54 void __iomem *ipi_base_addr = ((void __iomem *)
  55                                (__IA64_UNCACHED_OFFSET | IA64_IPI_DEFAULT_BASE_ADDR));
  56
  57 /*
  58  * Legacy IRQ to IA-64 vector translation table.
  59  */
  60 __u8 isa_irq_to_vector_map[16] = {
  61         /* 8259 IRQ translation, first 16 entries */
  62         0x2f, 0x20, 0x2e, 0x2d, 0x2c, 0x2b, 0x2a, 0x29,
  63         0x28, 0x27, 0x26, 0x25, 0x24, 0x23, 0x22, 0x21
  64 };
  65 EXPORT_SYMBOL(isa_irq_to_vector_map);
  66
  67 static unsigned long ia64_vector_mask[BITS_TO_LONGS(IA64_MAX_DEVICE_VECTORS)];
  68
  69 int
  70 assign_irq_vector (int irq)
  71 {
  72         int pos, vector;
  73  again:
  74         pos = find_first_zero_bit(ia64_vector_mask, IA64_NUM_DEVICE_VECTORS);
  75         vector = IA64_FIRST_DEVICE_VECTOR + pos;
  76         if (vector > IA64_LAST_DEVICE_VECTOR)
  77                 return -ENOSPC;
  78         if (test_and_set_bit(pos, ia64_vector_mask))
  79                 goto again;
  80         return vector;
  81 }
  82
  83 void
  84 free_irq_vector (int vector)
  85 {
  86         int pos;
  87
  88         if (vector < IA64_FIRST_DEVICE_VECTOR || vector > IA64_LAST_DEVICE_VECTOR)
  89                 return;
  90
  91         pos = vector - IA64_FIRST_DEVICE_VECTOR;
  92         if (!test_and_clear_bit(pos, ia64_vector_mask))
  93                 printk(KERN_WARNING "%s: double free!\n", __FUNCTION__);
  94 }
  95
  96 int
  97 reserve_irq_vector (int vector)
  98 {
  99         int pos;
 100
 101         if (vector < IA64_FIRST_DEVICE_VECTOR ||
 102             vector > IA64_LAST_DEVICE_VECTOR)
 103                 return -EINVAL;
 104
 105         pos = vector - IA64_FIRST_DEVICE_VECTOR;
 106         return test_and_set_bit(pos, ia64_vector_mask);
 107 }
 108
 109 /*
 110  * Dynamic irq allocate and deallocation for MSI
 111  */
 112 int create_irq(void)
 113 {
 114         int vector = assign_irq_vector(AUTO_ASSIGN);
 115
 116         if (vector >= 0)
 117                 dynamic_irq_init(vector);
 118
 119         return vector;
 120 }
 121
 122 void destroy_irq(unsigned int irq)
 123 {
 124         dynamic_irq_cleanup(irq);
 125         free_irq_vector(irq);
 126 }
 127
 128 #ifdef CONFIG_SMP
 129 #       define IS_RESCHEDULE(vec)       (vec == IA64_IPI_RESCHEDULE)
 130 #else
 131 #       define IS_RESCHEDULE(vec)       (0)
 132 #endif
 133 /*
 134  * That's where the IVT branches when we get an external
 135  * interrupt. This branches to the correct hardware IRQ handler via
 136  * function ptr.
 137  */
 138 void
 139 ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
 140 {
 141         struct pt_regs *old_regs = set_irq_regs(regs);
 142         unsigned long saved_tpr;
 143
 144 #if IRQ_DEBUG
 145         {
 146                 unsigned long bsp, sp;
 147
 148                 /*
 149                  * Note: if the interrupt happened while executing in
 150                  * the context switch routine (ia64_switch_to), we may
 151                  * get a spurious stack overflow here.  This is
 152                  * because the register and the memory stack are not
 153                  * switched atomically.
 154                  */
 155                 bsp = ia64_getreg(_IA64_REG_AR_BSP);
 156                 sp = ia64_getreg(_IA64_REG_SP);
 157
 158                 if ((sp - bsp) < 1024) {
 159                         static unsigned char count;
 160                         static long last_time;
 161
 162                         if (jiffies - last_time > 5*HZ)
 163                                 count = 0;
 164                         if (++count < 5) {
 165                                 last_time = jiffies;
 166                                 printk("ia64_handle_irq: DANGER: less than "
 167                                        "1KB of free stack space!!\n"
 168                                        "(bsp=0x%lx, sp=%lx)\n", bsp, sp);
 169                         }
 170                 }
 171         }
 172 #endif /* IRQ_DEBUG */
 173
 174         /*
 175          * Always set TPR to limit maximum interrupt nesting depth to
 176          * 16 (without this, it would be ~240, which could easily lead
 177          * to kernel stack overflows).
 178          */
 179         irq_enter();
 180         saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
 181         ia64_srlz_d();
 182         while (vector != IA64_SPURIOUS_INT_VECTOR) {
 183                 if (unlikely(IS_RESCHEDULE(vector)))
 184                          kstat_this_cpu.irqs[vector]++;
 185                 else {
 186                         ia64_setreg(_IA64_REG_CR_TPR, vector);
 187                         ia64_srlz_d();
 188
 189                         generic_handle_irq(local_vector_to_irq(vector));
 190
 191                         /*
 192                          * Disable interrupts and send EOI:
 193                          */
 194                         local_irq_disable();
 195                         ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
 196                 }
 197                 ia64_eoi();
 198                 vector = ia64_get_ivr();
 199         }
 200         /*
 201          * This must be done *after* the ia64_eoi().  For example, the keyboard softirq
 202          * handler needs to be able to wait for further keyboard interrupts, which can't
 203          * come through until ia64_eoi() has been done.
 204          */
 205         irq_exit();
 206         set_irq_regs(old_regs);
 207 }
 208
 209 #ifdef CONFIG_HOTPLUG_CPU
 210 /*
 211  * This function emulates a interrupt processing when a cpu is about to be
 212  * brought down.
 213  */
 214 void ia64_process_pending_intr(void)
 215 {
 216         ia64_vector vector;
 217         unsigned long saved_tpr;
 218         extern unsigned int vectors_in_migration[NR_IRQS];
 219
 220         vector = ia64_get_ivr();
 221
 222          irq_enter();
 223          saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
 224          ia64_srlz_d();
 225
 226          /*
 227           * Perform normal interrupt style processing
 228           */
 229         while (vector != IA64_SPURIOUS_INT_VECTOR) {
 230                 if (unlikely(IS_RESCHEDULE(vector)))
 231                          kstat_this_cpu.irqs[vector]++;
 232                 else {
 233                         struct pt_regs *old_regs = set_irq_regs(NULL);
 234
 235                         ia64_setreg(_IA64_REG_CR_TPR, vector);
 236                         ia64_srlz_d();
 237
 238                         /*
 239                          * Now try calling normal ia64_handle_irq as it would have got called
 240                          * from a real intr handler. Try passing null for pt_regs, hopefully
 241                          * it will work. I hope it works!.
 242                          * Probably could shared code.
 243                          */
 244                         vectors_in_migration[local_vector_to_irq(vector)]=0;
 245                         generic_handle_irq(local_vector_to_irq(vector));
 246                         set_irq_regs(old_regs);
 247
 248                         /*
 249                          * Disable interrupts and send EOI
 250                          */
 251                         local_irq_disable();
 252                         ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
 253                 }
 254                 ia64_eoi();
 255                 vector = ia64_get_ivr();
 256         }
 257         irq_exit();
 258 }
 259 #endif
 260
 261
 262 #ifdef CONFIG_SMP
 263 extern irqreturn_t handle_IPI (int irq, void *dev_id);
 264
 265 static irqreturn_t dummy_handler (int irq, void *dev_id)
 266 {
 267         BUG();
 268 }
 269
 270 static struct irqaction ipi_irqaction = {
 271         .handler =      handle_IPI,
 272         .flags =        IRQF_DISABLED,
 273         .name =         "IPI"
 274 };
 275
 276 static struct irqaction resched_irqaction = {
 277         .handler =      dummy_handler,
 278         .flags =        SA_INTERRUPT,
 279         .name =         "resched"
 280 };
 281 #endif
 282
 283 void
 284 register_percpu_irq (ia64_vector vec, struct irqaction *action)
 285 {
 286         irq_desc_t *desc;
 287         unsigned int irq;
 288
 289         for (irq = 0; irq < NR_IRQS; ++irq)
 290                 if (irq_to_vector(irq) == vec) {
 291                         desc = irq_desc + irq;
 292                         desc->status |= IRQ_PER_CPU;
 293                         desc->chip = &irq_type_ia64_lsapic;
 294                         if (action)
 295                                 setup_irq(irq, action);
 296                 }
 297 }
 298
 299 void __init
 300 init_IRQ (void)
 301 {
 302         register_percpu_irq(IA64_SPURIOUS_INT_VECTOR, NULL);
 303 #ifdef CONFIG_SMP
 304         register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction);
 305         register_percpu_irq(IA64_IPI_RESCHEDULE, &resched_irqaction);
 306 #endif
 307 #ifdef CONFIG_PERFMON
 308         pfm_init_percpu();
 309 #endif
 310         platform_irq_init();
 311 }
 312
 313 void
 314 ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
 315 {
 316         void __iomem *ipi_addr;
 317         unsigned long ipi_data;
 318         unsigned long phys_cpu_id;
 319
 320 #ifdef CONFIG_SMP
 321         phys_cpu_id = cpu_physical_id(cpu);
 322 #else
 323         phys_cpu_id = (ia64_getreg(_IA64_REG_CR_LID) >> 16) & 0xffff;
 324 #endif
 325
 326         /*
 327          * cpu number is in 8bit ID and 8bit EID
 328          */
 329
 330         ipi_data = (delivery_mode << 8) | (vector & 0xff);
 331         ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));
 332
 333         writeq(ipi_data, ipi_addr);
 334 }