[PATCH] hpet: Remove BKL from hpet_open

[PATCH] hpet: Remove BKL from hpet_open

[John Kacur]

>From 8dea55a14071c1b3445fc8a934f96c47dd35a1e1 Mon Sep 17 00:00:00 2001
From: John Kacur <jkacur@redhat.com>
Date: Sun, 18 Oct 2009 22:07:01 +0200
Subject: [PATCH] hpet: Remove BKL from hpet_open

hpet_open received the BKL from commit 48b81880519274d2a8b3e9919a47d91d05a1c964
during the BKL pushdown.

It is not needed here because everything is serialized via the hpet_lock

Signed-off-by: John Kacur <jkacur@redhat.com>
---
 drivers/char/hpet.c |    4 ----
 1 files changed, 0 insertions(+), 4 deletions(-)

diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 70a770a..5e83828 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -14,7 +14,6 @@
 #include <linux/interrupt.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
-#include <linux/smp_lock.h>
 #include <linux/types.h>
 #include <linux/miscdevice.h>
 #include <linux/major.h>
@@ -251,7 +250,6 @@ static int hpet_open(struct inode *inode, struct file *file)
 	if (file->f_mode & FMODE_WRITE)
 		return -EINVAL;
 
-	lock_kernel();
 	spin_lock_irq(&hpet_lock);
 
 	for (devp = NULL, hpetp = hpets; hpetp && !devp; hpetp = hpetp->hp_next)
@@ -265,7 +263,6 @@ static int hpet_open(struct inode *inode, struct file *file)
 
 	if (!devp) {
 		spin_unlock_irq(&hpet_lock);
-		unlock_kernel();
 		return -EBUSY;
 	}
 
@@ -273,7 +270,6 @@ static int hpet_open(struct inode *inode, struct file *file)
 	devp->hd_irqdata = 0;
 	devp->hd_flags |= HPET_OPEN;
 	spin_unlock_irq(&hpet_lock);
-	unlock_kernel();
 
 	hpet_timer_set_irq(devp);
 
-- 
1.6.0.6

hpet: Convert to unlocked_ioctl

[John Kacur]

This patch converts the hpet_ioctl to the unlocked version. It is meant to 
be applied after the patch that removed the BKL from the hpet_open 
function.

Note that .llseek is already explicitly set to no_llseek.

>From 84e9964c4c7eeb4e99bb51e3a10768c1f869f259 Mon Sep 17 00:00:00 2001
From: John Kacur <jkacur@redhat.com>
Date: Wed, 21 Oct 2009 13:34:42 +0200
Subject: [PATCH] hpet: Convert to unlocked_ioctl

The ioctl functions here rely on their own locking using the hpet_lock spinlock.

Signed-off-by: John Kacur <jkacur@redhat.com>
---
 drivers/char/hpet.c |   16 ++++++----------
 1 files changed, 6 insertions(+), 10 deletions(-)

diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index 5e83828..e7754cd 100644
--- a/drivers/char/hpet.c
+++ b/drivers/char/hpet.c
@@ -426,11 +426,9 @@ static int hpet_release(struct inode *inode, struct file *file)
 	return 0;
 }
 
-static int hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
+static long hpet_ioctl_common(struct hpet_dev *, int, unsigned long, int);
 
-static int
-hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
-	   unsigned long arg)
+static long hpet_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
 {
 	struct hpet_dev *devp;
 
@@ -438,7 +436,7 @@ hpet_ioctl(struct inode *inode, struct file *file, unsigned int cmd,
 	return hpet_ioctl_common(devp, cmd, arg, 0);
 }
 
-static int hpet_ioctl_ieon(struct hpet_dev *devp)
+static long hpet_ioctl_ieon(struct hpet_dev *devp)
 {
 	struct hpet_timer __iomem *timer;
 	struct hpet __iomem *hpet;
@@ -545,13 +543,13 @@ static inline unsigned long hpet_time_div(struct hpets *hpets,
 	return (unsigned long)m;
 }
 
-static int
+static long
 hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
 {
 	struct hpet_timer __iomem *timer;
 	struct hpet __iomem *hpet;
 	struct hpets *hpetp;
-	int err;
+	long err = 0;
 	unsigned long v;
 
 	switch (cmd) {
@@ -570,8 +568,6 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
 		return -EINVAL;
 	}
 
-	err = 0;
-
 	switch (cmd) {
 	case HPET_IE_OFF:
 		if ((devp->hd_flags & HPET_IE) == 0)
@@ -651,7 +647,7 @@ static const struct file_operations hpet_fops = {
 	.llseek = no_llseek,
 	.read = hpet_read,
 	.poll = hpet_poll,
-	.ioctl = hpet_ioctl,
+	.unlocked_ioctl = hpet_ioctl,
 	.open = hpet_open,
 	.release = hpet_release,
 	.fasync = hpet_fasync,
-- 
1.6.0.6

Re: hpet: Convert to unlocked_ioctl

[Clemens Ladisch]

John Kacur wrote:
> This patch converts the hpet_ioctl to the unlocked version. It is meant to 
> be applied after the patch that removed the BKL from the hpet_open 
> function.
> 
> From: John Kacur <jkacur@redhat.com>
> Date: Wed, 21 Oct 2009 13:34:42 +0200
> Subject: [PATCH] hpet: Convert to unlocked_ioctl
> 
> The ioctl functions here rely on their own locking using the hpet_lock spinlock.
> 
> Signed-off-by: John Kacur <jkacur@redhat.com>

Acked-by: Clemens Ladisch <clemens@ladisch.de>
(for both patches)