From: Ralf Baechle <ralf@linux-mips.org>
To: Andrew Morton <akpm@linux-foundation.org>,
Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Subject: [PATCH] Optimize i8259 code a bit.
Date: Sun, 28 Oct 2007 23:11:45 +0000 [thread overview]
Message-ID: <20071028231145.GA9515@linux-mips.org> (raw)
The timer code always calls the clock_event_device set_net_event and
set_mode methods with interrupts disabled, so no need to use
spin_lock_irqsave / spin_unlock_irqrestore for those.
arch/mips/kernel/i8253.c | 12 ++++--------
arch/x86/kernel/i8253.c | 12 ++++--------
2 files changed, 8 insertions(+), 16 deletions(-)
diff --git a/arch/mips/kernel/i8253.c b/arch/mips/kernel/i8253.c
index 5d9830d..1b54674 100644
--- a/arch/mips/kernel/i8253.c
+++ b/arch/mips/kernel/i8253.c
@@ -23,9 +23,7 @@ static DEFINE_SPINLOCK(i8253_lock);
static void init_pit_timer(enum clock_event_mode mode,
struct clock_event_device *evt)
{
- unsigned long flags;
-
- spin_lock_irqsave(&i8253_lock, flags);
+ spin_lock(&i8253_lock);
switch(mode) {
case CLOCK_EVT_MODE_PERIODIC:
@@ -54,7 +52,7 @@ static void init_pit_timer(enum clock_event_mode mode,
/* Nothing to do here */
break;
}
- spin_unlock_irqrestore(&i8253_lock, flags);
+ spin_unlock(&i8253_lock);
}
/*
@@ -64,12 +62,10 @@ static void init_pit_timer(enum clock_event_mode mode,
*/
static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
{
- unsigned long flags;
-
- spin_lock_irqsave(&i8253_lock, flags);
+ spin_lock(&i8253_lock);
outb_p(delta & 0xff , PIT_CH0); /* LSB */
outb(delta >> 8 , PIT_CH0); /* MSB */
- spin_unlock_irqrestore(&i8253_lock, flags);
+ spin_unlock(&i8253_lock);
return 0;
}
diff --git a/arch/x86/kernel/i8253.c b/arch/x86/kernel/i8253.c
index a42c807..5246515 100644
--- a/arch/x86/kernel/i8253.c
+++ b/arch/x86/kernel/i8253.c
@@ -31,9 +31,7 @@ struct clock_event_device *global_clock_event;
static void init_pit_timer(enum clock_event_mode mode,
struct clock_event_device *evt)
{
- unsigned long flags;
-
- spin_lock_irqsave(&i8253_lock, flags);
+ spin_lock(&i8253_lock);
switch(mode) {
case CLOCK_EVT_MODE_PERIODIC:
@@ -62,7 +60,7 @@ static void init_pit_timer(enum clock_event_mode mode,
/* Nothing to do here */
break;
}
- spin_unlock_irqrestore(&i8253_lock, flags);
+ spin_unlock(&i8253_lock);
}
/*
@@ -72,12 +70,10 @@ static void init_pit_timer(enum clock_event_mode mode,
*/
static int pit_next_event(unsigned long delta, struct clock_event_device *evt)
{
- unsigned long flags;
-
- spin_lock_irqsave(&i8253_lock, flags);
+ spin_lock(&i8253_lock);
outb_p(delta & 0xff , PIT_CH0); /* LSB */
outb(delta >> 8 , PIT_CH0); /* MSB */
- spin_unlock_irqrestore(&i8253_lock, flags);
+ spin_unlock(&i8253_lock);
return 0;
}
next reply other threads:[~2007-10-28 15:49 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-10-28 23:11 Ralf Baechle [this message]
2007-10-28 16:54 ` [PATCH] Optimize i8259 code a bit Thomas Gleixner
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20071028231145.GA9515@linux-mips.org \
--to=ralf@linux-mips.org \
--cc=akpm@linux-foundation.org \
--cc=linux-kernel@vger.kernel.org \
--cc=tglx@linutronix.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox