[PATCH v5] HPET: Remove the BKL.

From: David John
Date: Tue Oct 21 2008 - 01:58:58 EST


Remove calls to the BKL as concurrent access is protected
by the spinlock hpet_lock.

Signed-off-by: David John <davidjon@xxxxxxxxxxx>
---
drivers/char/hpet.c | 41 ++++++++++++++++++++++++-----------------
1 files changed, 24 insertions(+), 17 deletions(-)

diff --git a/drivers/char/hpet.c b/drivers/char/hpet.c
index b3f5dbc..ba40096 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>
@@ -194,7 +193,6 @@ 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)
@@ -209,7 +207,6 @@ static int hpet_open(struct inode *inode, struct file *file)

if (!devp) {
spin_unlock_irq(&hpet_lock);
- unlock_kernel();
return -EBUSY;
}

@@ -217,7 +214,6 @@ 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();

return 0;
}
@@ -375,15 +371,12 @@ 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;
-
- devp = file->private_data;
+ struct hpet_dev *devp = file->private_data;
return hpet_ioctl_common(devp, cmd, arg, 0);
}

@@ -414,7 +407,6 @@ static int hpet_ioctl_ieon(struct hpet_dev *devp)

if (readl(&timer->hpet_config) & Tn_INT_TYPE_CNF_MASK)
devp->hd_flags |= HPET_SHARED_IRQ;
- spin_unlock_irq(&hpet_lock);

irq = devp->hd_hdwirq;

@@ -432,7 +424,6 @@ static int hpet_ioctl_ieon(struct hpet_dev *devp)
}

if (irq == 0) {
- spin_lock_irq(&hpet_lock);
devp->hd_flags ^= HPET_IE;
spin_unlock_irq(&hpet_lock);
return -EIO;
@@ -463,7 +454,9 @@ static int hpet_ioctl_ieon(struct hpet_dev *devp)
isr = 1 << (devp - devp->hd_hpets->hp_dev);
writel(isr, &hpet->hpet_isr);
}
+
writeq(g, &timer->hpet_config);
+ spin_unlock_irq(&hpet_lock);
local_irq_restore(flags);

return 0;
@@ -480,13 +473,13 @@ 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;
unsigned long v;

switch (cmd) {
@@ -509,8 +502,11 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)

switch (cmd) {
case HPET_IE_OFF:
- if ((devp->hd_flags & HPET_IE) == 0)
+ spin_lock_irq(&hpet_lock);
+ if ((devp->hd_flags & HPET_IE) == 0) {
+ spin_unlock_irq(&hpet_lock);
break;
+ }
v = readq(&timer->hpet_config);
v &= ~Tn_INT_ENB_CNF_MASK;
writeq(v, &timer->hpet_config);
@@ -519,11 +515,13 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
devp->hd_irq = 0;
}
devp->hd_flags ^= HPET_IE;
+ spin_unlock_irq(&hpet_lock);
break;
case HPET_INFO:
{
struct hpet_info info;

+ spin_lock_irq(&hpet_lock);
if (devp->hd_ireqfreq)
info.hi_ireqfreq =
hpet_time_div(hpetp, devp->hd_ireqfreq);
@@ -533,6 +531,7 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
readq(&timer->hpet_config) & Tn_PER_INT_CAP_MASK;
info.hi_hpet = hpetp->hp_which;
info.hi_timer = devp - hpetp->hp_dev;
+ spin_unlock_irq(&hpet_lock);
if (kernel)
memcpy((void *)arg, &info, sizeof(info));
else
@@ -542,16 +541,21 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
break;
}
case HPET_EPI:
+ spin_lock_irq(&hpet_lock);
v = readq(&timer->hpet_config);
if ((v & Tn_PER_INT_CAP_MASK) == 0) {
+ spin_unlock_irq(&hpet_lock);
err = -ENXIO;
break;
}
devp->hd_flags |= HPET_PERIODIC;
+ spin_unlock_irq(&hpet_lock);
break;
case HPET_DPI:
+ spin_lock_irq(&hpet_lock);
v = readq(&timer->hpet_config);
if ((v & Tn_PER_INT_CAP_MASK) == 0) {
+ spin_unlock_irq(&hpet_lock);
err = -ENXIO;
break;
}
@@ -562,6 +566,7 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
writeq(v, &timer->hpet_config);
}
devp->hd_flags &= ~HPET_PERIODIC;
+ spin_unlock_irq(&hpet_lock);
break;
case HPET_IRQFREQ:
if (!kernel && (arg > hpet_max_freq) &&
@@ -575,7 +580,9 @@ hpet_ioctl_common(struct hpet_dev *devp, int cmd, unsigned long arg, int kernel)
break;
}

+ spin_lock_irq(&hpet_lock);
devp->hd_ireqfreq = hpet_time_div(hpetp, arg);
+ spin_unlock_irq(&hpet_lock);
}

return err;
@@ -586,7 +593,7 @@ 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,
--
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