2009-10-18 20:12:00

by John Kacur

Subject: [PATCH] hpet: Remove BKL from hpet_open

>From 8dea55a14071c1b3445fc8a934f96c47dd35a1e1 Mon Sep 17 00:00:00 2001
From: John Kacur <[email protected]>
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 <[email protected]>
---
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

2009-10-21 11:44:09

by John Kacur

Subject: hpet: Convert to unlocked_ioctl

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 <[email protected]>
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 <[email protected]>
---
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

2009-10-21 11:52:19

by Clemens Ladisch

Subject: Re: hpet: Convert to unlocked_ioctl

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 <[email protected]>
> 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 <[email protected]>

Acked-by: Clemens Ladisch <[email protected]>
(for both patches)