[PATCH 1/1] Misc: phantom, move to unlocked_ioctl

Jiri Slaby
2007-05-18T20:35:06Z

phantom, move to unlocked_ioctl

phantom's ioctl is often (4000 times a sec or so) invoked, don't acquire BKL
and block other processes.

Signed-off-by: Jiri Slaby <xslaby@phantom.fi.muni.cz>

---
commit 79b7336ec18e967de0026d2cc08de47da6333761
tree d180d46c4bf38ee42adf8949e9f746f893aae32b
parent 34762198ff54f921aa49be10dcc21efaf53f4a4c
author Jiri Slaby <xslaby@phantom.fi.muni.cz> Fri, 18 May 2007 22:02:59 +0200
committer Jiri Slaby <xslaby@phantom.fi.muni.cz> Fri, 18 May 2007 22:02:59 +0200

drivers/misc/phantom.c | 20 ++++++++++++++++----
1 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/misc/phantom.c b/drivers/misc/phantom.c
index 35b139b..6249767 100644
--- a/drivers/misc/phantom.c
+++ b/drivers/misc/phantom.c
@@ -47,6 +47,7 @@ struct phantom_device {
struct cdev cdev;

struct mutex open_lock;
+ spinlock_t ioctl_lock;
};

static unsigned char phantom_devices[PHANTOM_MAX_MINORS];
@@ -71,8 +72,8 @@ static int phantom_status(struct phantom_device *dev, unsigned long newstat)
* File ops
*/

-static int phantom_ioctl(struct inode *inode, struct file *file, u_int cmd,
- u_long arg)
+static long phantom_ioctl(struct file *file, unsigned int cmd,
+ unsigned long arg)
{
struct phantom_device *dev = file->private_data;
struct phm_regs rs;
@@ -92,24 +93,30 @@ static int phantom_ioctl(struct inode *inode, struct file *file, u_int cmd,
if (r.reg > 7)
return -EINVAL;

+ spin_lock(&dev->ioctl_lock);
if (r.reg == PHN_CONTROL && (r.value & PHN_CTL_IRQ) &&
- phantom_status(dev, dev->status | PHB_RUNNING))
+ phantom_status(dev, dev->status | PHB_RUNNING)){
+ spin_unlock(&dev->ioctl_lock);
return -ENODEV;
+ }

pr_debug("phantom: writing %x to %u\n", r.value, r.reg);
iowrite32(r.value, dev->iaddr + r.reg);

if (r.reg == PHN_CONTROL && !(r.value & PHN_CTL_IRQ))
phantom_status(dev, dev->status & ~PHB_RUNNING);
+ spin_unlock(&dev->ioctl_lock);
break;
case PHN_SET_REGS:
if (copy_from_user(&rs, argp, sizeof(rs)))
return -EFAULT;

pr_debug("phantom: SRS %u regs %x\n", rs.count, rs.mask);
+ spin_lock(&dev->ioctl_lock);
for (i = 0; i < min(rs.count, 8U); i++)
if ((1 << i) & rs.mask)
iowrite32(rs.values[i], dev->oaddr + i);
+ spin_unlock(&dev->ioctl_lock);
break;
case PHN_GET_REG:
if (copy_from_user(&r, argp, sizeof(r)))
@@ -118,7 +125,9 @@ static int phantom_ioctl(struct inode *inode, struct file *file, u_int cmd,
if (r.reg > 7)
return -EINVAL;

+ spin_lock(&dev->ioctl_lock);
r.value = ioread32(dev->iaddr + r.reg);
+ spin_unlock(&dev->ioctl_lock);

if (copy_to_user(argp, &r, sizeof(r)))
return -EFAULT;
@@ -128,9 +137,11 @@ static int phantom_ioctl(struct inode *inode, struct file *file, u_int cmd,
return -EFAULT;

pr_debug("phantom: GRS %u regs %x\n", rs.count, rs.mask);
+ spin_lock(&dev->ioctl_lock);
for (i = 0; i < min(rs.count, 8U); i++)
if ((1 << i) & rs.mask)
rs.values[i] = ioread32(dev->iaddr + i);
+ spin_unlock(&dev->ioctl_lock);

if (copy_to_user(argp, &rs, sizeof(rs)))
return -EFAULT;
@@ -199,7 +210,7 @@ static unsigned int phantom_poll(struct file *file, poll_table *wait)
static struct file_operations phantom_file_ops = {
.open = phantom_open,
.release = phantom_release,
- .ioctl = phantom_ioctl,
+ .unlocked_ioctl = phantom_ioctl,
.poll = phantom_poll,
};

@@ -282,6 +293,7 @@ static int __devinit phantom_probe(struct pci_dev *pdev,
}

mutex_init(&pht->open_lock);
+ spin_lock_init(&pht->ioctl_lock);
init_waitqueue_head(&pht->wait);
cdev_init(&pht->cdev, &phantom_file_ops);
pht->cdev.owner = THIS_MODULE;