From 4417c73305f60e46a2370bcaf3635981f5dbc050 Mon Sep 17 00:00:00 2001
From: Scott Wood <scottwood@freescale.com>
Date: Thu, 3 Jan 2013 13:25:38 +0000
Subject: [PATCH] openpic: IRQ_check: search the queue a word at a time
Search the queue more efficiently by first looking for a non-zero word,
and then using the common bit-searching function to find the bit within
the word. It would be even nicer if bitops_ffsl() could be hooked up
to the compiler intrinsic so that bit-searching instructions could be
used, but that's another matter.
Signed-off-by: Scott Wood <scottwood@freescale.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
---
hw/openpic.c | 28 ++++++++++++++++------------
1 file changed, 16 insertions(+), 12 deletions(-)
diff --git a/hw/openpic.c b/hw/openpic.c
index 66179c22cb..7645d6770e 100644
--- a/hw/openpic.c
+++ b/hw/openpic.c
@@ -277,21 +277,25 @@ static inline int IRQ_testbit(IRQQueue *q, int n_IRQ)
static void IRQ_check(OpenPICState *opp, IRQQueue *q)
{
- int next, i;
- int priority;
+ int irq = -1;
+ int next = -1;
+ int priority = -1;
- next = -1;
- priority = -1;
- for (i = 0; i < opp->max_irq; i++) {
- if (IRQ_testbit(q, i)) {
- DPRINTF("IRQ_check: irq %d set ivpr_pr=%d pr=%d\n",
- i, IVPR_PRIORITY(opp->src[i].ivpr), priority);
- if (IVPR_PRIORITY(opp->src[i].ivpr) > priority) {
- next = i;
- priority = IVPR_PRIORITY(opp->src[i].ivpr);
- }
+ for (;;) {
+ irq = find_next_bit(q->queue, opp->max_irq, irq + 1);
+ if (irq == opp->max_irq) {
+ break;
+ }
+
+ DPRINTF("IRQ_check: irq %d set ivpr_pr=%d pr=%d\n",
+ irq, IVPR_PRIORITY(opp->src[irq].ivpr), priority);
+
+ if (IVPR_PRIORITY(opp->src[irq].ivpr) > priority) {
+ next = irq;
+ priority = IVPR_PRIORITY(opp->src[irq].ivpr);
}
}
+
q->next = next;
q->priority = priority;
}