release/src-rt-6.x.4708/linux/linux-2.6.36/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 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 ia64_vector __ia64_irq_to_vector(int irq)
  37 {
  38         return irq_cfg[irq].vector;
  39 }
  40
  41 unsigned int __ia64_local_vector_to_irq (ia64_vector vec)
  42 {
  43         return __get_cpu_var(vector_irq)[vec];
  44 }
  45 #endif
  46
  47 /*
  48  * Interrupt statistics:
  49  */
  50
  51 atomic_t irq_err_count;
  52
  53 /*
  54  * /proc/interrupts printing:
  55  */
  56
  57 int show_interrupts(struct seq_file *p, void *v)
  58 {
  59         int i = *(loff_t *) v, j;
  60         struct irqaction * action;
  61         unsigned long flags;
  62
  63         if (i == 0) {
  64                 char cpuname[16];
  65                 seq_printf(p, "     ");
  66                 for_each_online_cpu(j) {
  67                         snprintf(cpuname, 10, "CPU%d", j);
  68                         seq_printf(p, "%10s ", cpuname);
  69                 }
  70                 seq_putc(p, '\n');
  71         }
  72
  73         if (i < NR_IRQS) {
  74                 raw_spin_lock_irqsave(&irq_desc[i].lock, flags);
  75                 action = irq_desc[i].action;
  76                 if (!action)
  77                         goto skip;
  78                 seq_printf(p, "%3d: ",i);
  79 #ifndef CONFIG_SMP
  80                 seq_printf(p, "%10u ", kstat_irqs(i));
  81 #else
  82                 for_each_online_cpu(j) {
  83                         seq_printf(p, "%10u ", kstat_irqs_cpu(i, j));
  84                 }
  85 #endif
  86                 seq_printf(p, " %14s", irq_desc[i].chip->name);
  87                 seq_printf(p, "  %s", action->name);
  88
  89                 for (action=action->next; action; action = action->next)
  90                         seq_printf(p, ", %s", action->name);
  91
  92                 seq_putc(p, '\n');
  93 skip:
  94                 raw_spin_unlock_irqrestore(&irq_desc[i].lock, flags);
  95         } else if (i == NR_IRQS)
  96                 seq_printf(p, "ERR: %10u\n", atomic_read(&irq_err_count));
  97         return 0;
  98 }
  99
 100 #ifdef CONFIG_SMP
 101 static char irq_redir [NR_IRQS]; // = { [0 ... NR_IRQS-1] = 1 };
 102
 103 void set_irq_affinity_info (unsigned int irq, int hwid, int redir)
 104 {
 105         if (irq < NR_IRQS) {
 106                 cpumask_copy(irq_desc[irq].affinity,
 107                              cpumask_of(cpu_logical_id(hwid)));
 108                 irq_redir[irq] = (char) (redir & 0xff);
 109         }
 110 }
 111
 112 bool is_affinity_mask_valid(const struct cpumask *cpumask)
 113 {
 114         if (ia64_platform_is("sn2")) {
 115                 /* Only allow one CPU to be specified in the smp_affinity mask */
 116                 if (cpumask_weight(cpumask) != 1)
 117                         return false;
 118         }
 119         return true;
 120 }
 121
 122 #endif /* CONFIG_SMP */
 123
 124 #ifdef CONFIG_HOTPLUG_CPU
 125 unsigned int vectors_in_migration[NR_IRQS];
 126
 127 /*
 128  * Since cpu_online_mask is already updated, we just need to check for
 129  * affinity that has zeros
 130  */
 131 static void migrate_irqs(void)
 132 {
 133         struct irq_desc *desc;
 134         int             irq, new_cpu;
 135
 136         for (irq=0; irq < NR_IRQS; irq++) {
 137                 desc = irq_desc + irq;
 138
 139                 if (desc->status == IRQ_DISABLED)
 140                         continue;
 141
 142                 /*
 143                  * No handling for now.
 144                  * TBD: Implement a disable function so we can now
 145                  * tell CPU not to respond to these local intr sources.
 146                  * such as ITV,CPEI,MCA etc.
 147                  */
 148                 if (desc->status == IRQ_PER_CPU)
 149                         continue;
 150
 151                 if (cpumask_any_and(irq_desc[irq].affinity, cpu_online_mask)
 152                     >= nr_cpu_ids) {
 153                         /*
 154                          * Save it for phase 2 processing
 155                          */
 156                         vectors_in_migration[irq] = irq;
 157
 158                         new_cpu = cpumask_any(cpu_online_mask);
 159
 160                         /*
 161                          * Al three are essential, currently WARN_ON.. maybe panic?
 162                          */
 163                         if (desc->chip && desc->chip->disable &&
 164                                 desc->chip->enable && desc->chip->set_affinity) {
 165                                 desc->chip->disable(irq);
 166                                 desc->chip->set_affinity(irq,
 167                                                          cpumask_of(new_cpu));
 168                                 desc->chip->enable(irq);
 169                         } else {
 170                                 WARN_ON((!(desc->chip) || !(desc->chip->disable) ||
 171                                                 !(desc->chip->enable) ||
 172                                                 !(desc->chip->set_affinity)));
 173                         }
 174                 }
 175         }
 176 }
 177
 178 void fixup_irqs(void)
 179 {
 180         unsigned int irq;
 181         extern void ia64_process_pending_intr(void);
 182         extern volatile int time_keeper_id;
 183
 184         /* Mask ITV to disable timer */
 185         ia64_set_itv(1 << 16);
 186
 187         /*
 188          * Find a new timesync master
 189          */
 190         if (smp_processor_id() == time_keeper_id) {
 191                 time_keeper_id = cpumask_first(cpu_online_mask);
 192                 printk ("CPU %d is now promoted to time-keeper master\n", time_keeper_id);
 193         }
 194
 195         /*
 196          * Phase 1: Locate IRQs bound to this cpu and
 197          * relocate them for cpu removal.
 198          */
 199         migrate_irqs();
 200
 201         /*
 202          * Phase 2: Perform interrupt processing for all entries reported in
 203          * local APIC.
 204          */
 205         ia64_process_pending_intr();
 206
 207         /*
 208          * Phase 3: Now handle any interrupts not captured in local APIC.
 209          * This is to account for cases that device interrupted during the time the
 210          * rte was being disabled and re-programmed.
 211          */
 212         for (irq=0; irq < NR_IRQS; irq++) {
 213                 if (vectors_in_migration[irq]) {
 214                         struct pt_regs *old_regs = set_irq_regs(NULL);
 215
 216                         vectors_in_migration[irq]=0;
 217                         generic_handle_irq(irq);
 218                         set_irq_regs(old_regs);
 219                 }
 220         }
 221
 222         /*
 223          * Now let processor die. We do irq disable and max_xtp() to
 224          * ensure there is no more interrupts routed to this processor.
 225          * But the local timer interrupt can have 1 pending which we
 226          * take care in timer_interrupt().
 227          */
 228         max_xtp();
 229         local_irq_disable();
 230 }
 231 #endif