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Commit c15395c0 authored by Jiri Slaby's avatar Jiri Slaby Committed by Linus Torvalds
Browse files

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: default avatarJiri Slaby <xslaby@phantom.fi.muni.cz>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 14441960

drivers/misc/phantom.c

+14 −4
Original line number Diff line number Diff line
@@ -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;