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>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/drivers/misc/phantom.c b/drivers/misc/phantom.c
index 35b139b..4b5959b 100644 (file)
--- 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)))
@@ -128,9 +135,11 @@ 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 +208,7 @@ 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 +291,7 @@ 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;