Staging: vme: Replace semaphore by mutex.
Replace binary semaphore by mutex for code cleanup. Mutex also gives better performance than semaphore. Add 'mutex_destroy()' in 'vme_user_remove()' routine. Signed-off-by: Santosh Nayak <santoshprasadnayak@gmail.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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@ -27,7 +27,7 @@
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#include <linux/module.h>
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#include <linux/pagemap.h>
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#include <linux/pci.h>
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#include <linux/semaphore.h>
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#include <linux/mutex.h>
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#include <linux/slab.h>
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#include <linux/spinlock.h>
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#include <linux/syscalls.h>
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@ -95,7 +95,7 @@ struct image_desc {
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void *kern_buf; /* Buffer address in kernel space */
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dma_addr_t pci_buf; /* Buffer address in PCI address space */
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unsigned long long size_buf; /* Buffer size */
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struct semaphore sem; /* Semaphore for locking image */
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struct mutex mutex; /* Mutex for locking image */
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struct device *device; /* Sysfs device */
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struct vme_resource *resource; /* VME resource */
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int users; /* Number of current users */
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@ -168,7 +168,7 @@ static int vme_user_open(struct inode *inode, struct file *file)
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int err;
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unsigned int minor = MINOR(inode->i_rdev);
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down(&image[minor].sem);
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mutex_lock(&image[minor].mutex);
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/* Allow device to be opened if a resource is needed and allocated. */
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if (minor < CONTROL_MINOR && image[minor].resource == NULL) {
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printk(KERN_ERR "No resources allocated for device\n");
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@ -179,12 +179,12 @@ static int vme_user_open(struct inode *inode, struct file *file)
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/* Increment user count */
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image[minor].users++;
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up(&image[minor].sem);
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mutex_unlock(&image[minor].mutex);
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return 0;
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err_res:
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up(&image[minor].sem);
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mutex_unlock(&image[minor].mutex);
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return err;
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}
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@ -193,12 +193,12 @@ static int vme_user_release(struct inode *inode, struct file *file)
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{
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unsigned int minor = MINOR(inode->i_rdev);
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down(&image[minor].sem);
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mutex_lock(&image[minor].mutex);
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/* Decrement user count */
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image[minor].users--;
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up(&image[minor].sem);
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mutex_unlock(&image[minor].mutex);
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return 0;
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}
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@ -325,14 +325,14 @@ static ssize_t vme_user_read(struct file *file, char __user *buf, size_t count,
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if (minor == CONTROL_MINOR)
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return 0;
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down(&image[minor].sem);
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mutex_lock(&image[minor].mutex);
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/* XXX Do we *really* want this helper - we can use vme_*_get ? */
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image_size = vme_get_size(image[minor].resource);
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/* Ensure we are starting at a valid location */
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if ((*ppos < 0) || (*ppos > (image_size - 1))) {
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up(&image[minor].sem);
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mutex_unlock(&image[minor].mutex);
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return 0;
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}
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@ -353,8 +353,7 @@ static ssize_t vme_user_read(struct file *file, char __user *buf, size_t count,
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retval = -EINVAL;
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}
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up(&image[minor].sem);
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mutex_unlock(&image[minor].mutex);
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if (retval > 0)
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*ppos += retval;
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@ -372,13 +371,13 @@ static ssize_t vme_user_write(struct file *file, const char __user *buf,
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if (minor == CONTROL_MINOR)
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return 0;
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down(&image[minor].sem);
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mutex_lock(&image[minor].mutex);
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image_size = vme_get_size(image[minor].resource);
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/* Ensure we are starting at a valid location */
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if ((*ppos < 0) || (*ppos > (image_size - 1))) {
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up(&image[minor].sem);
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mutex_unlock(&image[minor].mutex);
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return 0;
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}
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@ -398,8 +397,8 @@ static ssize_t vme_user_write(struct file *file, const char __user *buf,
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default:
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retval = -EINVAL;
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}
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up(&image[minor].sem);
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mutex_unlock(&image[minor].mutex);
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if (retval > 0)
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*ppos += retval;
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@ -416,7 +415,7 @@ static loff_t vme_user_llseek(struct file *file, loff_t off, int whence)
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if (minor == CONTROL_MINOR)
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return -EINVAL;
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down(&image[minor].sem);
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mutex_lock(&image[minor].mutex);
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image_size = vme_get_size(image[minor].resource);
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switch (whence) {
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@ -430,19 +429,19 @@ static loff_t vme_user_llseek(struct file *file, loff_t off, int whence)
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absolute = image_size + off;
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break;
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default:
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up(&image[minor].sem);
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mutex_unlock(&image[minor].mutex);
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return -EINVAL;
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break;
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}
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if ((absolute < 0) || (absolute >= image_size)) {
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up(&image[minor].sem);
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mutex_unlock(&image[minor].mutex);
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return -EINVAL;
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}
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file->f_pos = absolute;
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up(&image[minor].sem);
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mutex_unlock(&image[minor].mutex);
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return absolute;
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}
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@ -696,7 +695,7 @@ static int __devinit vme_user_probe(struct vme_dev *vdev)
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for (i = 0; i < VME_DEVS; i++) {
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image[i].kern_buf = NULL;
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image[i].pci_buf = 0;
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sema_init(&image[i].sem, 1);
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mutex_init(&image[i].mutex);
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image[i].device = NULL;
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image[i].resource = NULL;
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image[i].users = 0;
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@ -858,8 +857,10 @@ static int __devexit vme_user_remove(struct vme_dev *dev)
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int i;
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/* Remove sysfs Entries */
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for (i = 0; i < VME_DEVS; i++)
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for (i = 0; i < VME_DEVS; i++) {
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mutex_destroy(&image[i].mutex);
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device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i));
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}
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class_destroy(vme_user_sysfs_class);
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for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) {
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