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   1 /*
   2  * linux/arch/ia64/kernel/irq.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/config.h>
  18 #include <linux/module.h>
  19
  20 #include <linux/jiffies.h>
  21 #include <linux/errno.h>
  22 #include <linux/init.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/ioport.h>
  25 #include <linux/kernel_stat.h>
  26 #include <linux/slab.h>
  27 #include <linux/ptrace.h>
  28 #include <linux/random.h>       /* for rand_initialize_irq() */
  29 #include <linux/signal.h>
  30 #include <linux/smp.h>
  31 #include <linux/smp_lock.h>
  32 #include <linux/threads.h>
  33 #include <linux/bitops.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 #ifdef CONFIG_SMP
 110 #       define IS_RESCHEDULE(vec)       (vec == IA64_IPI_RESCHEDULE)
 111 #else
 112 #       define IS_RESCHEDULE(vec)       (0)
 113 #endif
 114 /*
 115  * That's where the IVT branches when we get an external
 116  * interrupt. This branches to the correct hardware IRQ handler via
 117  * function ptr.
 118  */
 119 void
 120 ia64_handle_irq (ia64_vector vector, struct pt_regs *regs)
 121 {
 122         unsigned long saved_tpr;
 123
 124 #if IRQ_DEBUG
 125         {
 126                 unsigned long bsp, sp;
 127
 128                 /*
 129                  * Note: if the interrupt happened while executing in
 130                  * the context switch routine (ia64_switch_to), we may
 131                  * get a spurious stack overflow here.  This is
 132                  * because the register and the memory stack are not
 133                  * switched atomically.
 134                  */
 135                 bsp = ia64_getreg(_IA64_REG_AR_BSP);
 136                 sp = ia64_getreg(_IA64_REG_SP);
 137
 138                 if ((sp - bsp) < 1024) {
 139                         static unsigned char count;
 140                         static long last_time;
 141
 142                         if (jiffies - last_time > 5*HZ)
 143                                 count = 0;
 144                         if (++count < 5) {
 145                                 last_time = jiffies;
 146                                 printk("ia64_handle_irq: DANGER: less than "
 147                                        "1KB of free stack space!!\n"
 148                                        "(bsp=0x%lx, sp=%lx)\n", bsp, sp);
 149                         }
 150                 }
 151         }
 152 #endif /* IRQ_DEBUG */
 153
 154         /*
 155          * Always set TPR to limit maximum interrupt nesting depth to
 156          * 16 (without this, it would be ~240, which could easily lead
 157          * to kernel stack overflows).
 158          */
 159         irq_enter();
 160         saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
 161         ia64_srlz_d();
 162         while (vector != IA64_SPURIOUS_INT_VECTOR) {
 163                 if (!IS_RESCHEDULE(vector)) {
 164                         ia64_setreg(_IA64_REG_CR_TPR, vector);
 165                         ia64_srlz_d();
 166
 167                         __do_IRQ(local_vector_to_irq(vector), regs);
 168
 169                         /*
 170                          * Disable interrupts and send EOI:
 171                          */
 172                         local_irq_disable();
 173                         ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
 174                 }
 175                 ia64_eoi();
 176                 vector = ia64_get_ivr();
 177         }
 178         /*
 179          * This must be done *after* the ia64_eoi().  For example, the keyboard softirq
 180          * handler needs to be able to wait for further keyboard interrupts, which can't
 181          * come through until ia64_eoi() has been done.
 182          */
 183         irq_exit();
 184 }
 185
 186 #ifdef CONFIG_HOTPLUG_CPU
 187 /*
 188  * This function emulates a interrupt processing when a cpu is about to be
 189  * brought down.
 190  */
 191 void ia64_process_pending_intr(void)
 192 {
 193         ia64_vector vector;
 194         unsigned long saved_tpr;
 195         extern unsigned int vectors_in_migration[NR_IRQS];
 196
 197         vector = ia64_get_ivr();
 198
 199          irq_enter();
 200          saved_tpr = ia64_getreg(_IA64_REG_CR_TPR);
 201          ia64_srlz_d();
 202
 203          /*
 204           * Perform normal interrupt style processing
 205           */
 206         while (vector != IA64_SPURIOUS_INT_VECTOR) {
 207                 if (!IS_RESCHEDULE(vector)) {
 208                         ia64_setreg(_IA64_REG_CR_TPR, vector);
 209                         ia64_srlz_d();
 210
 211                         /*
 212                          * Now try calling normal ia64_handle_irq as it would have got called
 213                          * from a real intr handler. Try passing null for pt_regs, hopefully
 214                          * it will work. I hope it works!.
 215                          * Probably could shared code.
 216                          */
 217                         vectors_in_migration[local_vector_to_irq(vector)]=0;
 218                         __do_IRQ(local_vector_to_irq(vector), NULL);
 219
 220                         /*
 221                          * Disable interrupts and send EOI
 222                          */
 223                         local_irq_disable();
 224                         ia64_setreg(_IA64_REG_CR_TPR, saved_tpr);
 225                 }
 226                 ia64_eoi();
 227                 vector = ia64_get_ivr();
 228         }
 229         irq_exit();
 230 }
 231 #endif
 232
 233
 234 #ifdef CONFIG_SMP
 235 extern irqreturn_t handle_IPI (int irq, void *dev_id, struct pt_regs *regs);
 236
 237 static struct irqaction ipi_irqaction = {
 238         .handler =      handle_IPI,
 239         .flags =        SA_INTERRUPT,
 240         .name =         "IPI"
 241 };
 242 #endif
 243
 244 void
 245 register_percpu_irq (ia64_vector vec, struct irqaction *action)
 246 {
 247         irq_desc_t *desc;
 248         unsigned int irq;
 249
 250         for (irq = 0; irq < NR_IRQS; ++irq)
 251                 if (irq_to_vector(irq) == vec) {
 252                         desc = irq_descp(irq);
 253                         desc->status |= IRQ_PER_CPU;
 254                         desc->handler = &irq_type_ia64_lsapic;
 255                         if (action)
 256                                 setup_irq(irq, action);
 257                 }
 258 }
 259
 260 void __init
 261 init_IRQ (void)
 262 {
 263         register_percpu_irq(IA64_SPURIOUS_INT_VECTOR, NULL);
 264 #ifdef CONFIG_SMP
 265         register_percpu_irq(IA64_IPI_VECTOR, &ipi_irqaction);
 266 #endif
 267 #ifdef CONFIG_PERFMON
 268         pfm_init_percpu();
 269 #endif
 270         platform_irq_init();
 271 }
 272
 273 void
 274 ia64_send_ipi (int cpu, int vector, int delivery_mode, int redirect)
 275 {
 276         void __iomem *ipi_addr;
 277         unsigned long ipi_data;
 278         unsigned long phys_cpu_id;
 279
 280 #ifdef CONFIG_SMP
 281         phys_cpu_id = cpu_physical_id(cpu);
 282 #else
 283         phys_cpu_id = (ia64_getreg(_IA64_REG_CR_LID) >> 16) & 0xffff;
 284 #endif
 285
 286         /*
 287          * cpu number is in 8bit ID and 8bit EID
 288          */
 289
 290         ipi_data = (delivery_mode << 8) | (vector & 0xff);
 291         ipi_addr = ipi_base_addr + ((phys_cpu_id << 4) | ((redirect & 1) << 3));
 292
 293         writeq(ipi_data, ipi_addr);
 294 }