Staging: vme: llseek support in user driver

Provide vme_user_llseek() implementation.

Signed-off-by: Arthur Benilov <arthur.benilov@iba-group.com>
Signed-off-by: Vincent Bossier <vincent.bossier@iba-group.com>
Acked-by: Martyn Welch <martyn.welch@ge.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

1 files changed, 33 insertions, 2 deletions

diff --git a/drivers/staging/vme/devices/vme_user.c b/drivers/staging/vme/devices/vme_user.c
index 48d46cadb13..ddecbe5105b 100644
--- a/drivers/staging/vme/devices/vme_user.c
+++ b/drivers/staging/vme/devices/vme_user.c
@@ -400,8 +400,39 @@ static ssize_t vme_user_write(struct file *file, const char *buf, size_t count,
 
 static loff_t vme_user_llseek(struct file *file, loff_t off, int whence)
 {
-        printk(KERN_ERR "Llseek currently incomplete\n");
-        return -EINVAL;
+        loff_t absolute = -1;
+        unsigned int minor = MINOR(file->f_dentry->d_inode->i_rdev);
+        size_t image_size;
+
+        down(&image[minor].sem);
+        image_size = vme_get_size(image[minor].resource);
+
+        switch (whence) {
+        case SEEK_SET:
+                absolute = off;
+                break;
+        case SEEK_CUR:
+                absolute = file->f_pos + off;
+                break;
+        case SEEK_END:
+                absolute = image_size + off;
+                break;
+        default:
+                up(&image[minor].sem);
+                return -EINVAL;
+                break;
+        }
+
+        if ((absolute < 0) || (absolute >= image_size)) {
+                up(&image[minor].sem);
+                return -EINVAL;
+        }
+
+        file->f_pos = absolute;
+
+        up(&image[minor].sem);
+
+        return absolute;
 }
 
 /*