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 "internals.h" /* only for activate_irq() damage.. */
  18
  19 /*
  20  * The IRQ bitmap provides a global map of bound IRQ vectors for a
  21  * given platform. Allocation of IRQs are either static through the CPU
  22  * vector map, or dynamic in the case of board mux vectors or MSI.
  23  *
  24  * As this is a central point for all IRQ controllers on the system,
  25  * each of the available sources are mapped out here. This combined with
  26  * sparseirq makes it quite trivial to keep the vector map tightly packed
  27  * when dynamically creating IRQs, as well as tying in to otherwise
  28  * unused irq_desc positions in the sparse array.
  29  */
  30
  31 /*
  32  * Dynamic IRQ allocation and deallocation
  33  */
  34 unsigned int create_irq_nr(unsigned int irq_want, int node)
  35 {
  36         int irq = irq_alloc_desc_at(irq_want, node);
  37         if (irq < 0)
  38                 return 0;
  39
  40         activate_irq(irq);
  41         return irq;
  42 }
  43
  44 int create_irq(void)
  45 {
  46         int irq = irq_alloc_desc(numa_node_id());
  47         if (irq >= 0)
  48                 activate_irq(irq);
  49
  50         return irq;
  51 }
  52
  53 void destroy_irq(unsigned int irq)
  54 {
  55         irq_free_desc(irq);
  56 }
  57
  58 void reserve_intc_vectors(struct intc_vect *vectors, unsigned int nr_vecs)
  59 {
  60         int i;
  61
  62         for (i = 0; i < nr_vecs; i++)
  63                 irq_reserve_irq(evt2irq(vectors[i].vect));
  64 }