arch/ia64/kernel/irq.c

   1 /*
   2  *      linux/arch/ia64/kernel/irq.c
   3  *
   4  *      Copyright (C) 1992, 1998 Linus Torvalds, Ingo Molnar
   5  *
   6  * This file contains the code used by various IRQ handling routines:
   7  * asking for different IRQ's should be done through these routines
   8  * instead of just grabbing them. Thus setups with different IRQ numbers
   9  * shouldn't result in any weird surprises, and installing new handlers
  10  * should be easier.
  11  *
  12  * Copyright (C) Ashok Raj<ashok.raj@intel.com>, Intel Corporation 2004
  13  *
  14  * 4/14/2004: Added code to handle cpu migration and do safe irq
  15  *                      migration without lossing interrupts for iosapic
  16  *                      architecture.
  17  */
  18
  19 #include <asm/delay.h>
  20 #include <asm/uaccess.h>
  21 #include <linux/module.h>
  22 #include <linux/seq_file.h>
  23 #include <linux/interrupt.h>
  24 #include <linux/kernel_stat.h>
  25
  26 /*
  27  * 'what should we do if we get a hw irq event on an illegal vector'.
  28  * each architecture has to answer this themselves.
  29  */
  30 void ack_bad_irq(unsigned int irq)
  31 {
  32         printk(KERN_ERR "Unexpected irq vector 0x%x on CPU %u!\n", irq, smp_processor_id());
  33 }
  34
  35 #ifdef CONFIG_IA64_GENERIC
  36 unsigned int __ia64_local_vector_to_irq (ia64_vector vec)
  37 {
  38         return (unsigned int) vec;
  39 }
  40 #endif
  41
  42 /*
  43  * Interrupt statistics:
  44  */
  45
  46 atomic_t irq_err_count;
  47
  48 /*
  49  * /proc/interrupts printing:
  50  */
  51
  52 int show_interrupts(struct seq_file *p, void *v)
  53 {
  54         int i = *(loff_t *) v, j;
  55         struct irqaction * action;
  56         unsigned long flags;
  57
  58         if (i == 0) {
  59                 seq_printf(p, "           ");
  60                 for (j=0; j<NR_CPUS; j++)
  61                         if (cpu_online(j))
  62                                 seq_printf(p, "CPU%d       ",j);
  63                 seq_putc(p, '\n');
  64         }
  65
  66         if (i < NR_IRQS) {
  67                 spin_lock_irqsave(&irq_desc[i].lock, flags);
  68                 action = irq_desc[i].action;
  69                 if (!action)
  70                         goto skip;
  71                 seq_printf(p, "%3d: ",i);
  72 #ifndef CONFIG_SMP
  73                 seq_printf(p, "%10u ", kstat_irqs(i));
  74 #else
  75                 for (j = 0; j < NR_CPUS; j++)
  76                         if (cpu_online(j))
  77                                 seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  78 #endif
  79                 seq_printf(p, " %14s", irq_desc[i].handler->typename);
  80                 seq_printf(p, "  %s", action->name);
  81
  82                 for (action=action->next; action; action = action->next)
  83                         seq_printf(p, ", %s", action->name);
  84
  85                 seq_putc(p, '\n');
  86 skip:
  87                 spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  88         } else if (i == NR_IRQS)
  89                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
  90         return 0;
  91 }
  92
  93 #ifdef CONFIG_SMP
  94 /*
  95  * This is updated when the user sets irq affinity via /proc
  96  */
  97 static cpumask_t __cacheline_aligned pending_irq_cpumask[NR_IRQS];
  98 static unsigned long pending_irq_redir[BITS_TO_LONGS(NR_IRQS)];
  99
 100 static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 };
 101
 102 /*
 103  * Arch specific routine for deferred write to iosapic rte to reprogram
 104  * intr destination.
 105  */
 106 void proc_set_irq_affinity(unsigned int irq, cpumask_t mask_val)
 107 {
 108         pending_irq_cpumask[irq] = mask_val;
 109 }
 110
 111 void set_irq_affinity_info (unsigned int irq, int hwid, int redir)
 112 {
 113         cpumask_t mask = CPU_MASK_NONE;
 114
 115         cpu_set(cpu_logical_id(hwid), mask);
 116
 117         if (irq < NR_IRQS) {
 118                 irq_affinity[irq] = mask;
 119                 irq_redir[irq] = (char) (redir & 0xff);
 120         }
 121 }
 122
 123
 124 void move_irq(int irq)
 125 {
 126         /* note - we hold desc->lock */
 127         cpumask_t tmp;
 128         irq_desc_t *desc = irq_descp(irq);
 129         int redir = test_bit(irq, pending_irq_redir);
 130
 131         if (unlikely(!desc->handler->set_affinity))
 132                 return;
 133
 134         if (!cpus_empty(pending_irq_cpumask[irq])) {
 135                 cpus_and(tmp, pending_irq_cpumask[irq], cpu_online_map);
 136                 if (unlikely(!cpus_empty(tmp))) {
 137                         desc->handler->set_affinity(irq | (redir ? IA64_IRQ_REDIRECTED : 0),
 138                                                     pending_irq_cpumask[irq]);
 139                 }
 140                 cpus_clear(pending_irq_cpumask[irq]);
 141         }
 142 }
 143
 144
 145 #endif /* CONFIG_SMP */
 146
 147 #ifdef CONFIG_HOTPLUG_CPU
 148 unsigned int vectors_in_migration[NR_IRQS];
 149
 150 /*
 151  * Since cpu_online_map is already updated, we just need to check for
 152  * affinity that has zeros
 153  */
 154 static void migrate_irqs(void)
 155 {
 156         cpumask_t       mask;
 157         irq_desc_t *desc;
 158         int             irq, new_cpu;
 159
 160         for (irq=0; irq < NR_IRQS; irq++) {
 161                 desc = irq_descp(irq);
 162
 163                 /*
 164                  * No handling for now.
 165                  * TBD: Implement a disable function so we can now
 166                  * tell CPU not to respond to these local intr sources.
 167                  * such as ITV,CPEI,MCA etc.
 168                  */
 169                 if (desc->status == IRQ_PER_CPU)
 170                         continue;
 171
 172                 cpus_and(mask, irq_affinity[irq], cpu_online_map);
 173                 if (any_online_cpu(mask) == NR_CPUS) {
 174                         /*
 175                          * Save it for phase 2 processing
 176                          */
 177                         vectors_in_migration[irq] = irq;
 178
 179                         new_cpu = any_online_cpu(cpu_online_map);
 180                         mask = cpumask_of_cpu(new_cpu);
 181
 182                         /*
 183                          * Al three are essential, currently WARN_ON.. maybe panic?
 184                          */
 185                         if (desc->handler && desc->handler->disable &&
 186                                 desc->handler->enable && desc->handler->set_affinity) {
 187                                 desc->handler->disable(irq);
 188                                 desc->handler->set_affinity(irq, mask);
 189                                 desc->handler->enable(irq);
 190                         } else {
 191                                 WARN_ON((!(desc->handler) || !(desc->handler->disable) ||
 192                                                 !(desc->handler->enable) ||
 193                                                 !(desc->handler->set_affinity)));
 194                         }
 195                 }
 196         }
 197 }
 198
 199 void fixup_irqs(void)
 200 {
 201         unsigned int irq;
 202         extern void ia64_process_pending_intr(void);
 203
 204         ia64_set_itv(1<<16);
 205         /*
 206          * Phase 1: Locate irq's bound to this cpu and
 207          * relocate them for cpu removal.
 208          */
 209         migrate_irqs();
 210
 211         /*
 212          * Phase 2: Perform interrupt processing for all entries reported in
 213          * local APIC.
 214          */
 215         ia64_process_pending_intr();
 216
 217         /*
 218          * Phase 3: Now handle any interrupts not captured in local APIC.
 219          * This is to account for cases that device interrupted during the time the
 220          * rte was being disabled and re-programmed.
 221          */
 222         for (irq=0; irq < NR_IRQS; irq++) {
 223                 if (vectors_in_migration[irq]) {
 224                         vectors_in_migration[irq]=0;
 225                         __do_IRQ(irq, NULL);
 226                 }
 227         }
 228
 229         /*
 230          * Now let processor die. We do irq disable and max_xtp() to
 231          * ensure there is no more interrupts routed to this processor.
 232          * But the local timer interrupt can have 1 pending which we
 233          * take care in timer_interrupt().
 234          */
 235         max_xtp();
 236         local_irq_disable();
 237 }
 238 #endif