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   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 IRQs 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 losing 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_each_online_cpu(j) {
  61                         seq_printf(p, "CPU%d       ",j);
  62                 }
  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_each_online_cpu(j) {
  76                         seq_printf(p, "%10u ", kstat_cpu(j).irqs[i]);
  77                 }
  78 #endif
  79                 seq_printf(p, " %14s", irq_desc[i].chip->name);
  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 static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 };
  95
  96 void set_irq_affinity_info (unsigned int irq, int hwid, int redir)
  97 {
  98         cpumask_t mask = CPU_MASK_NONE;
  99
 100         cpu_set(cpu_logical_id(hwid), mask);
 101
 102         if (irq < NR_IRQS) {
 103                 irq_desc[irq].affinity = mask;
 104                 irq_redir[irq] = (char) (redir & 0xff);
 105         }
 106 }
 107
 108 bool is_affinity_mask_valid(cpumask_t cpumask)
 109 {
 110         if (ia64_platform_is("sn2")) {
 111                 /* Only allow one CPU to be specified in the smp_affinity mask */
 112                 if (cpus_weight(cpumask) != 1)
 113                         return false;
 114         }
 115         return true;
 116 }
 117
 118 #endif /* CONFIG_SMP */
 119
 120 #ifdef CONFIG_HOTPLUG_CPU
 121 unsigned int vectors_in_migration[NR_IRQS];
 122
 123 /*
 124  * Since cpu_online_map is already updated, we just need to check for
 125  * affinity that has zeros
 126  */
 127 static void migrate_irqs(void)
 128 {
 129         cpumask_t       mask;
 130         irq_desc_t *desc;
 131         int             irq, new_cpu;
 132
 133         for (irq=0; irq < NR_IRQS; irq++) {
 134                 desc = irq_desc + irq;
 135
 136                 if (desc->status == IRQ_DISABLED)
 137                         continue;
 138
 139                 /*
 140                  * No handling for now.
 141                  * TBD: Implement a disable function so we can now
 142                  * tell CPU not to respond to these local intr sources.
 143                  * such as ITV,CPEI,MCA etc.
 144                  */
 145                 if (desc->status == IRQ_PER_CPU)
 146                         continue;
 147
 148                 cpus_and(mask, irq_desc[irq].affinity, cpu_online_map);
 149                 if (any_online_cpu(mask) == NR_CPUS) {
 150                         /*
 151                          * Save it for phase 2 processing
 152                          */
 153                         vectors_in_migration[irq] = irq;
 154
 155                         new_cpu = any_online_cpu(cpu_online_map);
 156                         mask = cpumask_of_cpu(new_cpu);
 157
 158                         /*
 159                          * Al three are essential, currently WARN_ON.. maybe panic?
 160                          */
 161                         if (desc->chip && desc->chip->disable &&
 162                                 desc->chip->enable && desc->chip->set_affinity) {
 163                                 desc->chip->disable(irq);
 164                                 desc->chip->set_affinity(irq, mask);
 165                                 desc->chip->enable(irq);
 166                         } else {
 167                                 WARN_ON((!(desc->chip) || !(desc->chip->disable) ||
 168                                                 !(desc->chip->enable) ||
 169                                                 !(desc->chip->set_affinity)));
 170                         }
 171                 }
 172         }
 173 }
 174
 175 void fixup_irqs(void)
 176 {
 177         unsigned int irq;
 178         extern void ia64_process_pending_intr(void);
 179         extern void ia64_disable_timer(void);
 180         extern volatile int time_keeper_id;
 181
 182         ia64_disable_timer();
 183
 184         /*
 185          * Find a new timesync master
 186          */
 187         if (smp_processor_id() == time_keeper_id) {
 188                 time_keeper_id = first_cpu(cpu_online_map);
 189                 printk ("CPU %d is now promoted to time-keeper master\n", time_keeper_id);
 190         }
 191
 192         /*
 193          * Phase 1: Locate IRQs bound to this cpu and
 194          * relocate them for cpu removal.
 195          */
 196         migrate_irqs();
 197
 198         /*
 199          * Phase 2: Perform interrupt processing for all entries reported in
 200          * local APIC.
 201          */
 202         ia64_process_pending_intr();
 203
 204         /*
 205          * Phase 3: Now handle any interrupts not captured in local APIC.
 206          * This is to account for cases that device interrupted during the time the
 207          * rte was being disabled and re-programmed.
 208          */
 209         for (irq=0; irq < NR_IRQS; irq++) {
 210                 if (vectors_in_migration[irq]) {
 211                         struct pt_regs *old_regs = set_irq_regs(NULL);
 212
 213                         vectors_in_migration[irq]=0;
 214                         generic_handle_irq(irq);
 215                         set_irq_regs(old_regs);
 216                 }
 217         }
 218
 219         /*
 220          * Now let processor die. We do irq disable and max_xtp() to
 221          * ensure there is no more interrupts routed to this processor.
 222          * But the local timer interrupt can have 1 pending which we
 223          * take care in timer_interrupt().
 224          */
 225         max_xtp();
 226         local_irq_disable();
 227 }
 228 #endif