git.oblomov.eu Git - linux-2.6/blob - kernel/irq/numa_migrate.c

   1 /*
   2  * NUMA irq-desc migration code
   3  *
   4  * Migrate IRQ data structures (irq_desc, chip_data, etc.) over to
   5  * the new "home node" of the IRQ.
   6  */
   7
   8 #include <linux/irq.h>
   9 #include <linux/module.h>
  10 #include <linux/random.h>
  11 #include <linux/interrupt.h>
  12 #include <linux/kernel_stat.h>
  13
  14 #include "internals.h"
  15
  16 static void init_copy_kstat_irqs(struct irq_desc *old_desc,
  17                                  struct irq_desc *desc,
  18                                  int cpu, int nr)
  19 {
  20         unsigned long bytes;
  21
  22         init_kstat_irqs(desc, cpu, nr);
  23
  24         if (desc->kstat_irqs != old_desc->kstat_irqs) {
  25                 /* Compute how many bytes we need per irq and allocate them */
  26                 bytes = nr * sizeof(unsigned int);
  27
  28                 memcpy(desc->kstat_irqs, old_desc->kstat_irqs, bytes);
  29         }
  30 }
  31
  32 static void free_kstat_irqs(struct irq_desc *old_desc, struct irq_desc *desc)
  33 {
  34         if (old_desc->kstat_irqs == desc->kstat_irqs)
  35                 return;
  36
  37         kfree(old_desc->kstat_irqs);
  38         old_desc->kstat_irqs = NULL;
  39 }
  40
  41 static void init_copy_one_irq_desc(int irq, struct irq_desc *old_desc,
  42                  struct irq_desc *desc, int cpu)
  43 {
  44         memcpy(desc, old_desc, sizeof(struct irq_desc));
  45         desc->cpu = cpu;
  46         lockdep_set_class(&desc->lock, &irq_desc_lock_class);
  47         init_copy_kstat_irqs(old_desc, desc, cpu, nr_cpu_ids);
  48         arch_init_copy_chip_data(old_desc, desc, cpu);
  49 }
  50
  51 static void free_one_irq_desc(struct irq_desc *old_desc, struct irq_desc *desc)
  52 {
  53         free_kstat_irqs(old_desc, desc);
  54         arch_free_chip_data(old_desc, desc);
  55 }
  56
  57 static struct irq_desc *__real_move_irq_desc(struct irq_desc *old_desc,
  58                                                 int cpu)
  59 {
  60         struct irq_desc *desc;
  61         unsigned int irq;
  62         unsigned long flags;
  63         int node;
  64
  65         irq = old_desc->irq;
  66
  67         spin_lock_irqsave(&sparse_irq_lock, flags);
  68
  69         /* We have to check it to avoid races with another CPU */
  70         desc = irq_desc_ptrs[irq];
  71
  72         if (desc && old_desc != desc)
  73                         goto out_unlock;
  74
  75         node = cpu_to_node(cpu);
  76         desc = kzalloc_node(sizeof(*desc), GFP_ATOMIC, node);
  77         printk(KERN_DEBUG "  move irq_desc for %d to cpu %d node %d\n",
  78                  irq, cpu, node);
  79         if (!desc) {
  80                 printk(KERN_ERR "can not get new irq_desc for moving\n");
  81                 /* still use old one */
  82                 desc = old_desc;
  83                 goto out_unlock;
  84         }
  85         init_copy_one_irq_desc(irq, old_desc, desc, cpu);
  86
  87         irq_desc_ptrs[irq] = desc;
  88
  89         /* free the old one */
  90         free_one_irq_desc(old_desc, desc);
  91         kfree(old_desc);
  92
  93 out_unlock:
  94         spin_unlock_irqrestore(&sparse_irq_lock, flags);
  95
  96         return desc;
  97 }
  98
  99 struct irq_desc *move_irq_desc(struct irq_desc *desc, int cpu)
 100 {
 101         int old_cpu;
 102         int node, old_node;
 103
 104         /* those all static, do move them */
 105         if (desc->irq < NR_IRQS_LEGACY)
 106                 return desc;
 107
 108         old_cpu = desc->cpu;
 109         printk(KERN_DEBUG
 110                  "try to move irq_desc from cpu %d to %d\n", old_cpu, cpu);
 111         if (old_cpu != cpu) {
 112                 node = cpu_to_node(cpu);
 113                 old_node = cpu_to_node(old_cpu);
 114                 if (old_node != node)
 115                         desc = __real_move_irq_desc(desc, cpu);
 116                 else
 117                         desc->cpu = cpu;
 118         }
 119
 120         return desc;
 121 }
 122