LXR linux/drivers/sh/intc/irqdomain.c

   1/*
   2 * IRQ domain support for SH INTC subsystem
   3 *
   4 * Copyright (C) 2012  Paul Mundt
   5 *
   6 * This file is subject to the terms and conditions of the GNU General Public
   7 * License.  See the file "COPYING" in the main directory of this archive
   8 * for more details.
   9 */
  10#define pr_fmt(fmt) "intc: " fmt
  11
  12#include <linux/irqdomain.h>
  13#include <linux/sh_intc.h>
  14#include <linux/export.h>
  15#include "internals.h"
  16
  17/**
  18 * intc_irq_domain_evt_xlate() - Generic xlate for vectored IRQs.
  19 *
  20 * This takes care of exception vector to hwirq translation through
  21 * by way of evt2irq() translation.
  22 *
  23 * Note: For platforms that use a flat vector space without INTEVT this
  24 * basically just mimics irq_domain_xlate_onecell() by way of a nopped
  25 * out evt2irq() implementation.
  26 */
  27static int intc_evt_xlate(struct irq_domain *d, struct device_node *ctrlr,
  28                          const u32 *intspec, unsigned int intsize,
  29                          unsigned long *out_hwirq, unsigned int *out_type)
  30{
  31        if (WARN_ON(intsize < 1))
  32                return -EINVAL;
  33
  34        *out_hwirq = evt2irq(intspec[0]);
  35        *out_type = IRQ_TYPE_NONE;
  36
  37        return 0;
  38}
  39
  40static const struct irq_domain_ops intc_evt_ops = {
  41        .xlate          = intc_evt_xlate,
  42};
  43
  44void __init intc_irq_domain_init(struct intc_desc_int *d,
  45                                 struct intc_hw_desc *hw)
  46{
  47        unsigned int irq_base, irq_end;
  48
  49        /*
  50         * Quick linear revmap check
  51         */
  52        irq_base = evt2irq(hw->vectors[0].vect);
  53        irq_end = evt2irq(hw->vectors[hw->nr_vectors - 1].vect);
  54
  55        /*
  56         * Linear domains have a hard-wired assertion that IRQs start at
  57         * 0 in order to make some performance optimizations. Lamely
  58         * restrict the linear case to these conditions here, taking the
  59         * tree penalty for linear cases with non-zero hwirq bases.
  60         */
  61        if (irq_base == 0 && irq_end == (irq_base + hw->nr_vectors - 1))
  62                d->domain = irq_domain_add_linear(NULL, hw->nr_vectors,
  63                                                  &intc_evt_ops, NULL);
  64        else
  65                d->domain = irq_domain_add_tree(NULL, &intc_evt_ops, NULL);
  66
  67        BUG_ON(!d->domain);
  68}
  69