Commit 4c29e979 authored by Alan Cox's avatar Alan Cox Committed by Greg Kroah-Hartman
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Staging: sep: Implement some proper open/close methods 



Use the mutex as a protection for open close rather than leaving it hanging
invalidly across userspace.

Signed-off-by: default avatarAlan Cox <alan@linux.intel.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@suse.de>
parent 6f13ea3d

drivers/staging/sep/sep_dev.h

+2 −0
Original line number Diff line number Diff line
@@ -32,6 +32,8 @@ struct sep_device { 
	/* pointer to pci dev */

	struct pci_dev *pdev;



	unsigned long in_use;



	unsigned long io_bus;

	unsigned long io_end_bus;

	unsigned long io_memory_size;

drivers/staging/sep/sep_driver.c

+50 −39
Original line number Diff line number Diff line
@@ -296,53 +296,67 @@ static void *sep_shared_area_bus_to_virt(struct sep_device *sep, 
}





/*----------------------------------------------------------------------

  open function of the character driver - must only lock the mutex

	must also release the memory data pool allocations

------------------------------------------------------------------------*/

static int sep_open(struct inode *inode, struct file *filp)

/**

 *	sep_try_open		-	attempt to open a SEP device

 *	@sep: device to attempt to open

 *

 *	Atomically attempt to get ownership of a SEP device.

 *	Returns 1 if the device was opened, 0 on failure.

 */



static int sep_try_open(struct sep_device *sep)

{

	int error = 0;

	if (!test_and_set_bit(0, &sep->in_use))

		return 1;

	return 0;

}



/**

 *	sep_open		-	device open method

 *	@inode: inode of sep device

 *	@filp: file handle to sep device

 *

 *	Open method for the SEP device. Called when userspace opens

 *	the SEP device node. Must also release the memory data pool

 *	allocations.

 *

 *	Returns zero on success otherwise an error code.

 */



	dbg("SEP Driver:--------> open start\n");

static int sep_open(struct inode *inode, struct file *filp)

{

	if (sep_dev == NULL)

		return -ENODEV;



	/* check the blocking mode */

	if (filp->f_flags & O_NDELAY)

		error = mutex_trylock(&sep_mutex);

	else

		/* lock mutex */

		mutex_lock(&sep_mutex);

	if (filp->f_flags & O_NDELAY) {

		if (sep_try_open(sep_dev) == 0)

			return -EAGAIN;

	} else

		if (wait_event_interruptible(sep_event, sep_try_open(sep_dev)) < 0)

			return -EINTR;



	/* check the error */

	if (error) {

		edbg("SEP Driver: down_interruptible failed\n");

		goto end_function;

	}

	/* Bind to the device, we only have one which makes it easy */

	filp->private_data = sep_dev;

	if (sep_dev == NULL)

		return -ENODEV;



	/* release data pool allocations */

	sep_dev->data_pool_bytes_allocated = 0;





end_function:

	dbg("SEP Driver:<-------- open end\n");

	return error;

	return 0;

}





/**

 *	sep_release		-	close a SEP device

 *	@inode: inode of SEP device

 *	@filp: file handle being closed

 *

 *	Called on the final close of a SEP device. As the open protects against

 *	multiple simultaenous opens that means this method is called when the

 *	final reference to the open handle is dropped.

 */





/*------------------------------------------------------------

	release function

-------------------------------------------------------------*/

static int sep_release(struct inode *inode_ptr, struct file *filp)

static int sep_release(struct inode *inode, struct file *filp)

{

	struct sep_driver *sep =  filp->private_data;

	dbg("----------->SEP Driver: sep_release start\n");



	struct sep_device *sep =  filp->private_data;

#if 0				/*!SEP_DRIVER_POLLING_MODE */

	/* close IMR */

	sep_write_reg(sep, HW_HOST_IMR_REG_ADDR, 0x7FFF);
@@ -350,15 +364,12 @@ static int sep_release(struct inode *inode_ptr, struct file *filp) 
	free_irq(SEP_DIRVER_IRQ_NUM, sep);



#endif

	/* unlock the sep mutex */

	mutex_unlock(&sep_mutex);

	dbg("SEP Driver:<-------- sep_release end\n");

	/* Ensure any blocked open progresses */

	clear_bit(0, &sep->in_use);

	wake_up(&sep_event);

	return 0;

}









/*---------------------------------------------------------------

  map function - this functions maps the message shared area

-----------------------------------------------------------------*/