linux-stable/drivers/sh/intc/irqdomain.c
Paul Mundt 1d6a21b0a6 sh: intc: initial irqdomain support.
Trivial support for irq domains, using either a linear map or radix tree
depending on the vector layout.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
2012-08-01 17:13:46 +09:00

68 lines
1.9 KiB
C

/*
* IRQ domain support for SH INTC subsystem
*
* Copyright (C) 2012 Paul Mundt
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*/
#define pr_fmt(fmt) "intc: " fmt
#include <linux/irqdomain.h>
#include <linux/sh_intc.h>
#include <linux/export.h>
#include "internals.h"
/**
* intc_irq_domain_evt_xlate() - Generic xlate for vectored IRQs.
*
* This takes care of exception vector to hwirq translation through
* by way of evt2irq() translation.
*
* Note: For platforms that use a flat vector space without INTEVT this
* basically just mimics irq_domain_xlate_onecell() by way of a nopped
* out evt2irq() implementation.
*/
static int intc_evt_xlate(struct irq_domain *d, struct device_node *ctrlr,
const u32 *intspec, unsigned int intsize,
unsigned long *out_hwirq, unsigned int *out_type)
{
if (WARN_ON(intsize < 1))
return -EINVAL;
*out_hwirq = evt2irq(intspec[0]);
*out_type = IRQ_TYPE_NONE;
return 0;
}
static const struct irq_domain_ops intc_evt_ops = {
.xlate = intc_evt_xlate,
};
void __init intc_irq_domain_init(struct intc_desc_int *d,
struct intc_hw_desc *hw)
{
unsigned int irq_base, irq_end;
/*
* Quick linear revmap check
*/
irq_base = evt2irq(hw->vectors[0].vect);
irq_end = evt2irq(hw->vectors[hw->nr_vectors - 1].vect);
/*
* Linear domains have a hard-wired assertion that IRQs start at
* 0 in order to make some performance optimizations. Lamely
* restrict the linear case to these conditions here, taking the
* tree penalty for linear cases with non-zero hwirq bases.
*/
if (irq_base == 0 && irq_end == (irq_base + hw->nr_vectors - 1))
d->domain = irq_domain_add_linear(NULL, hw->nr_vectors,
&intc_evt_ops, NULL);
else
d->domain = irq_domain_add_tree(NULL, &intc_evt_ops, NULL);
BUG_ON(!d->domain);
}