Add a bunch of cycle_kernel_lock() calls

All of the open() functions which don't need the BKL on their face may
still depend on its acquisition to serialize opens against driver
initialization.  So make those functions acquire then release the BKL to be
on the safe side.

Signed-off-by: Jonathan Corbet <corbet@lwn.net>

drivers/char/cs5535_gpio.c

@@ -17,6 +17,7 @@
 #include <linux/cdev.h>
 #include <linux/ioport.h>
 #include <linux/pci.h>
+#include <linux/smp_lock.h>
 #include <asm/uaccess.h>
 #include <asm/io.h>
 
@@ -153,12 +154,11 @@ static ssize_t cs5535_gpio_read(struct file *file, char __user *buf,
 	return count;
 }
 
-/* No BKL needed here - "mask" is the only global resource used
-   here and it's a boot-time parameter */
 static int cs5535_gpio_open(struct inode *inode, struct file *file)
 {
 	u32 m = iminor(inode);
 
+	cycle_kernel_lock();
 	/* the mask says which pins are usable by this driver */
 	if ((mask & (1 << m)) == 0)
 		return -EINVAL;