diff options
author | Paul Mundt <lethal@linux-sh.org> | 2012-01-24 03:41:55 -0500 |
---|---|---|
committer | Paul Mundt <lethal@linux-sh.org> | 2012-01-24 03:41:55 -0500 |
commit | b59f9f9775e643435bba76e30e59e47c19c56dee (patch) | |
tree | 55bc067e5d2da0fc01ef9808ded60d9234dde165 /drivers/sh/intc/chip.c | |
parent | 30377642138aadeef35a31c2f90dba0b6fa7b91a (diff) |
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: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'drivers/sh/intc/chip.c')
-rw-r--r-- | drivers/sh/intc/chip.c | 27 |
1 files changed, 6 insertions, 21 deletions
diff --git a/drivers/sh/intc/chip.c b/drivers/sh/intc/chip.c index db10adf63dd..012df2676a2 100644 --- a/drivers/sh/intc/chip.c +++ b/drivers/sh/intc/chip.c | |||
@@ -2,13 +2,14 @@ | |||
2 | * IRQ chip definitions for INTC IRQs. | 2 | * IRQ chip definitions for INTC IRQs. |
3 | * | 3 | * |
4 | * Copyright (C) 2007, 2008 Magnus Damm | 4 | * Copyright (C) 2007, 2008 Magnus Damm |
5 | * Copyright (C) 2009, 2010 Paul Mundt | 5 | * Copyright (C) 2009 - 2012 Paul Mundt |
6 | * | 6 | * |
7 | * This file is subject to the terms and conditions of the GNU General Public | 7 | * This file is subject to the terms and conditions of the GNU General Public |
8 | * License. See the file "COPYING" in the main directory of this archive | 8 | * License. See the file "COPYING" in the main directory of this archive |
9 | * for more details. | 9 | * for more details. |
10 | */ | 10 | */ |
11 | #include <linux/cpumask.h> | 11 | #include <linux/cpumask.h> |
12 | #include <linux/bsearch.h> | ||
12 | #include <linux/io.h> | 13 | #include <linux/io.h> |
13 | #include "internals.h" | 14 | #include "internals.h" |
14 | 15 | ||
@@ -117,28 +118,12 @@ static struct intc_handle_int *intc_find_irq(struct intc_handle_int *hp, | |||
117 | unsigned int nr_hp, | 118 | unsigned int nr_hp, |
118 | unsigned int irq) | 119 | unsigned int irq) |
119 | { | 120 | { |
120 | int i; | 121 | struct intc_handle_int key; |
121 | |||
122 | /* | ||
123 | * this doesn't scale well, but... | ||
124 | * | ||
125 | * this function should only be used for cerain uncommon | ||
126 | * operations such as intc_set_priority() and intc_set_type() | ||
127 | * and in those rare cases performance doesn't matter that much. | ||
128 | * keeping the memory footprint low is more important. | ||
129 | * | ||
130 | * one rather simple way to speed this up and still keep the | ||
131 | * memory footprint down is to make sure the array is sorted | ||
132 | * and then perform a bisect to lookup the irq. | ||
133 | */ | ||
134 | for (i = 0; i < nr_hp; i++) { | ||
135 | if ((hp + i)->irq != irq) | ||
136 | continue; | ||
137 | 122 | ||
138 | return hp + i; | 123 | key.irq = irq; |
139 | } | 124 | key.handle = 0; |
140 | 125 | ||
141 | return NULL; | 126 | return bsearch(&key, hp, nr_hp, sizeof(*hp), intc_handle_int_cmp); |
142 | } | 127 | } |
143 | 128 | ||
144 | int intc_set_priority(unsigned int irq, unsigned int prio) | 129 | int intc_set_priority(unsigned int irq, unsigned int prio) |