drivers/sh/intc/dynamic.c

   1 /*
   2  * Dynamic IRQ management
   3  *
   4  * Copyright (C) 2010  Paul Mundt
   5  *
   6  * Modelled after arch/x86/kernel/apic/io_apic.c
   7  *
   8  * This file is subject to the terms and conditions of the GNU General Public
   9  * License.  See the file "COPYING" in the main directory of this archive
  10  * for more details.
  11  */
  12 #define pr_fmt(fmt) "intc: " fmt
  13
  14 #include <linux/irq.h>
  15 #include <linux/bitmap.h>
  16 #include <linux/spinlock.h>
  17 #include <linux/module.h>
  18 #include "internals.h" /* only for activate_irq() damage.. */
  19
  20 /*
  21  * The IRQ bitmap provides a global map of bound IRQ vectors for a
  22  * given platform. Allocation of IRQs are either static through the CPU
  23  * vector map, or dynamic in the case of board mux vectors or MSI.
  24  *
  25  * As this is a central point for all IRQ controllers on the system,
  26  * each of the available sources are mapped out here. This combined with
  27  * sparseirq makes it quite trivial to keep the vector map tightly packed
  28  * when dynamically creating IRQs, as well as tying in to otherwise
  29  * unused irq_desc positions in the sparse array.
  30  */
  31
  32 /*
  33  * Dynamic IRQ allocation and deallocation
  34  */
  35 unsigned int create_irq_nr(unsigned int irq_want, int node)
  36 {
  37         int irq = irq_alloc_desc_at(irq_want, node);
  38         if (irq < 0)
  39                 return 0;
  40
  41         activate_irq(irq);
  42         return irq;
  43 }
  44
  45 int create_irq(void)
  46 {
  47         int irq = irq_alloc_desc(numa_node_id());
  48         if (irq >= 0)
  49                 activate_irq(irq);
  50
  51         return irq;
  52 }
  53
  54 void destroy_irq(unsigned int irq)
  55 {
  56         irq_free_desc(irq);
  57 }
  58
  59 void reserve_intc_vectors(struct intc_vect *vectors, unsigned int nr_vecs)
  60 {
  61         int i;
  62
  63         for (i = 0; i < nr_vecs; i++)
  64                 irq_reserve_irq(evt2irq(vectors[i].vect));
  65 }