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