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Commit b59f9f97 authored by Paul Mundt's avatar Paul Mundt
Browse files

sh: intc: optimize intc IRQ lookup 



This ensures that the sense/prio lists are sorted at registration time,
enabling us to use a simple binary search for an optimized lookup
(something that had been on the TODO for some time).

Signed-off-by: default avatarPaul Mundt <lethal@linux-sh.org>
parent 30377642

drivers/sh/intc/chip.c

+6 −21
Original line number Diff line number Diff line
@@ -2,13 +2,14 @@ 
 * IRQ chip definitions for INTC IRQs.

 *

 * Copyright (C) 2007, 2008 Magnus Damm

 * Copyright (C) 2009, 2010 Paul Mundt

 * Copyright (C) 2009 - 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.

 */

#include <linux/cpumask.h>

#include <linux/bsearch.h>

#include <linux/io.h>

#include "internals.h"
@@ -117,28 +118,12 @@ static struct intc_handle_int *intc_find_irq(struct intc_handle_int *hp, 
					     unsigned int nr_hp,

					     unsigned int irq)

{

	int i;

	struct intc_handle_int key;



	/*

	 * this doesn't scale well, but...

	 *

	 * this function should only be used for cerain uncommon

	 * operations such as intc_set_priority() and intc_set_type()

	 * and in those rare cases performance doesn't matter that much.

	 * keeping the memory footprint low is more important.

	 *

	 * one rather simple way to speed this up and still keep the

	 * memory footprint down is to make sure the array is sorted

	 * and then perform a bisect to lookup the irq.

	 */

	for (i = 0; i < nr_hp; i++) {

		if ((hp + i)->irq != irq)

			continue;



		return hp + i;

	}

	key.irq = irq;

	key.handle = 0;



	return NULL;

	return bsearch(&key, hp, nr_hp, sizeof(*hp), intc_handle_int_cmp);

}



int intc_set_priority(unsigned int irq, unsigned int prio)

drivers/sh/intc/core.c

+8 −1
Original line number Diff line number Diff line
@@ -2,7 +2,7 @@ 
 * Shared interrupt handling code for IPR and INTC2 types of IRQs.

 *

 * Copyright (C) 2007, 2008 Magnus Damm

 * Copyright (C) 2009, 2010 Paul Mundt

 * Copyright (C) 2009 - 2012 Paul Mundt

 *

 * Based on intc2.c and ipr.c

 *
@@ -31,6 +31,7 @@ 
#include <linux/spinlock.h>

#include <linux/radix-tree.h>

#include <linux/export.h>

#include <linux/sort.h>

#include "internals.h"



LIST_HEAD(intc_list);
@@ -267,6 +268,9 @@ int __init register_intc_controller(struct intc_desc *desc) 
			k += save_reg(d, k, hw->prio_regs[i].set_reg, smp);

			k += save_reg(d, k, hw->prio_regs[i].clr_reg, smp);

		}



		sort(d->prio, hw->nr_prio_regs, sizeof(*d->prio),

		     intc_handle_int_cmp, NULL);

	}



	if (hw->sense_regs) {
@@ -277,6 +281,9 @@ int __init register_intc_controller(struct intc_desc *desc) 


		for (i = 0; i < hw->nr_sense_regs; i++)

			k += save_reg(d, k, hw->sense_regs[i].reg, 0);



		sort(d->sense, hw->nr_sense_regs, sizeof(*d->sense),

		     intc_handle_int_cmp, NULL);

	}



	if (hw->subgroups)

drivers/sh/intc/internals.h

+8 −0
Original line number Diff line number Diff line
@@ -108,6 +108,14 @@ static inline void activate_irq(int irq) 
#endif

}



static inline int intc_handle_int_cmp(const void *a, const void *b)

{

	const struct intc_handle_int *_a = a;

	const struct intc_handle_int *_b = b;



	return _a->irq - _b->irq;

}



/* access.c */

extern unsigned long

(*intc_reg_fns[])(unsigned long addr, unsigned long h, unsigned long data);