From ecb3b80ff968f1fffdbda9eb9aa8116db86ce220 Mon Sep 17 00:00:00 2001 From: Santosh Nayak Date: Tue, 3 Apr 2012 16:42:51 +0530 Subject: [PATCH] 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 Signed-off-by: Greg Kroah-Hartman --- drivers/staging/vme/devices/vme_user.c | 43 +++++++++++++++++----------------- 1 file changed, 22 insertions(+), 21 deletions(-) diff --git a/drivers/staging/vme/devices/vme_user.c b/drivers/staging/vme/devices/vme_user.c index 7dcd162..10269d599 100644 --- a/drivers/staging/vme/devices/vme_user.c +++ b/drivers/staging/vme/devices/vme_user.c @@ -27,7 +27,7 @@ #include #include #include -#include +#include #include #include #include @@ -95,7 +95,7 @@ struct image_desc { void *kern_buf; /* Buffer address in kernel space */ dma_addr_t pci_buf; /* Buffer address in PCI address space */ unsigned long long size_buf; /* Buffer size */ - struct semaphore sem; /* Semaphore for locking image */ + struct mutex mutex; /* Mutex for locking image */ struct device *device; /* Sysfs device */ struct vme_resource *resource; /* VME resource */ int users; /* Number of current users */ @@ -168,7 +168,7 @@ static int vme_user_open(struct inode *inode, struct file *file) int err; unsigned int minor = MINOR(inode->i_rdev); - down(&image[minor].sem); + mutex_lock(&image[minor].mutex); /* Allow device to be opened if a resource is needed and allocated. */ if (minor < CONTROL_MINOR && image[minor].resource == NULL) { printk(KERN_ERR "No resources allocated for device\n"); @@ -179,12 +179,12 @@ static int vme_user_open(struct inode *inode, struct file *file) /* Increment user count */ image[minor].users++; - up(&image[minor].sem); + mutex_unlock(&image[minor].mutex); return 0; err_res: - up(&image[minor].sem); + mutex_unlock(&image[minor].mutex); return err; } @@ -193,12 +193,12 @@ static int vme_user_release(struct inode *inode, struct file *file) { unsigned int minor = MINOR(inode->i_rdev); - down(&image[minor].sem); + mutex_lock(&image[minor].mutex); /* Decrement user count */ image[minor].users--; - up(&image[minor].sem); + mutex_unlock(&image[minor].mutex); return 0; } @@ -325,14 +325,14 @@ static ssize_t vme_user_read(struct file *file, char __user *buf, size_t count, if (minor == CONTROL_MINOR) return 0; - down(&image[minor].sem); + mutex_lock(&image[minor].mutex); /* XXX Do we *really* want this helper - we can use vme_*_get ? */ image_size = vme_get_size(image[minor].resource); /* Ensure we are starting at a valid location */ if ((*ppos < 0) || (*ppos > (image_size - 1))) { - up(&image[minor].sem); + mutex_unlock(&image[minor].mutex); return 0; } @@ -353,8 +353,7 @@ static ssize_t vme_user_read(struct file *file, char __user *buf, size_t count, retval = -EINVAL; } - up(&image[minor].sem); - + mutex_unlock(&image[minor].mutex); if (retval > 0) *ppos += retval; @@ -372,13 +371,13 @@ static ssize_t vme_user_write(struct file *file, const char __user *buf, if (minor == CONTROL_MINOR) return 0; - down(&image[minor].sem); + mutex_lock(&image[minor].mutex); image_size = vme_get_size(image[minor].resource); /* Ensure we are starting at a valid location */ if ((*ppos < 0) || (*ppos > (image_size - 1))) { - up(&image[minor].sem); + mutex_unlock(&image[minor].mutex); return 0; } @@ -398,8 +397,8 @@ static ssize_t vme_user_write(struct file *file, const char __user *buf, default: retval = -EINVAL; } - - up(&image[minor].sem); + + mutex_unlock(&image[minor].mutex); if (retval > 0) *ppos += retval; @@ -416,7 +415,7 @@ static loff_t vme_user_llseek(struct file *file, loff_t off, int whence) if (minor == CONTROL_MINOR) return -EINVAL; - down(&image[minor].sem); + mutex_lock(&image[minor].mutex); image_size = vme_get_size(image[minor].resource); switch (whence) { @@ -430,19 +429,19 @@ static loff_t vme_user_llseek(struct file *file, loff_t off, int whence) absolute = image_size + off; break; default: - up(&image[minor].sem); + mutex_unlock(&image[minor].mutex); return -EINVAL; break; } if ((absolute < 0) || (absolute >= image_size)) { - up(&image[minor].sem); + mutex_unlock(&image[minor].mutex); return -EINVAL; } file->f_pos = absolute; - up(&image[minor].sem); + mutex_unlock(&image[minor].mutex); return absolute; } @@ -696,7 +695,7 @@ static int __devinit vme_user_probe(struct vme_dev *vdev) for (i = 0; i < VME_DEVS; i++) { image[i].kern_buf = NULL; image[i].pci_buf = 0; - sema_init(&image[i].sem, 1); + mutex_init(&image[i].mutex); image[i].device = NULL; image[i].resource = NULL; image[i].users = 0; @@ -858,8 +857,10 @@ static int __devexit vme_user_remove(struct vme_dev *dev) int i; /* Remove sysfs Entries */ - for (i = 0; i < VME_DEVS; i++) + for (i = 0; i < VME_DEVS; i++) { + mutex_destroy(&image[i].mutex); device_destroy(vme_user_sysfs_class, MKDEV(VME_MAJOR, i)); + } class_destroy(vme_user_sysfs_class); for (i = MASTER_MINOR; i < (MASTER_MAX + 1); i++) { -- 2.7.4