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sparc: Remove BKL from apc
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commit ab77202 (sparc: arch/sparc/kernel/apc.c to unlocked_ioctl)
added lock/unlock_kernel() to the apc ioctl code.

The code needs no serialization at all. Neither put/get_user nor the
read/write access to the sbus devices require it. Remove BKL.

cycle_kernel_lock() was added during the big BKL pushdown. It should
ensure the serializiation against driver init code. In this case there
is nothing to serialize. Remove it as well.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Thomas Gleixner authored and David S. Miller committed Nov 3, 2009
1 parent 8401707 commit 49ab972
Showing 1 changed file with 10 additions and 27 deletions.
37 changes: 10 additions & 27 deletions arch/sparc/kernel/apc.c
Original file line number Diff line number Diff line change
Expand Up @@ -10,7 +10,6 @@
#include <linux/errno.h>
#include <linux/init.h>
#include <linux/miscdevice.h>
#include <linux/smp_lock.h>
#include <linux/pm.h>
#include <linux/of.h>
#include <linux/of_device.h>
Expand Down Expand Up @@ -76,7 +75,6 @@ static inline void apc_free(struct of_device *op)

static int apc_open(struct inode *inode, struct file *f)
{
cycle_kernel_lock();
return 0;
}

Expand All @@ -87,61 +85,46 @@ static int apc_release(struct inode *inode, struct file *f)

static long apc_ioctl(struct file *f, unsigned int cmd, unsigned long __arg)
{
__u8 inarg, __user *arg;

arg = (__u8 __user *) __arg;

lock_kernel();
__u8 inarg, __user *arg = (__u8 __user *) __arg;

switch (cmd) {
case APCIOCGFANCTL:
if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg)) {
unlock_kernel();
if (put_user(apc_readb(APC_FANCTL_REG) & APC_REGMASK, arg))
return -EFAULT;
}
break;

case APCIOCGCPWR:
if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg)) {
unlock_kernel();
if (put_user(apc_readb(APC_CPOWER_REG) & APC_REGMASK, arg))
return -EFAULT;
}
break;

case APCIOCGBPORT:
if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg)) {
unlock_kernel();
if (put_user(apc_readb(APC_BPORT_REG) & APC_BPMASK, arg))
return -EFAULT;
}
break;

case APCIOCSFANCTL:
if (get_user(inarg, arg)) {
unlock_kernel();
if (get_user(inarg, arg))
return -EFAULT;
}
apc_writeb(inarg & APC_REGMASK, APC_FANCTL_REG);
break;

case APCIOCSCPWR:
if (get_user(inarg, arg)) {
unlock_kernel();
if (get_user(inarg, arg))
return -EFAULT;
}
apc_writeb(inarg & APC_REGMASK, APC_CPOWER_REG);
break;

case APCIOCSBPORT:
if (get_user(inarg, arg)) {
unlock_kernel();
if (get_user(inarg, arg))
return -EFAULT;
}
apc_writeb(inarg & APC_BPMASK, APC_BPORT_REG);
break;

default:
unlock_kernel();
return -EINVAL;
};

unlock_kernel();
return 0;
}

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