Add the rt linux 4.1.3-rt3 as base

[kvmfornfv.git] / kernel / drivers / video / fbdev / core / fb_sys_fops.c

diff --git a/kernel/drivers/video/fbdev/core/fb_sys_fops.c b/kernel/drivers/video/fbdev/core/fb_sys_fops.c
new file mode 100644 (file)
index 0000000..ff275d7
--- /dev/null
+++ b/kernel/drivers/video/fbdev/core/fb_sys_fops.c
@@ -0,0 +1,104 @@
+/*
+ * linux/drivers/video/fb_sys_read.c - Generic file operations where
+ * framebuffer is in system RAM
+ *
+ * Copyright (C) 2007 Antonino Daplas <adaplas@pol.net>
+ *
+ * This file is subject to the terms and conditions of the GNU General Public
+ * License.  See the file COPYING in the main directory of this archive
+ * for more details.
+ *
+ */
+#include <linux/fb.h>
+#include <linux/module.h>
+#include <linux/uaccess.h>
+
+ssize_t fb_sys_read(struct fb_info *info, char __user *buf, size_t count,
+                   loff_t *ppos)
+{
+       unsigned long p = *ppos;
+       void *src;
+       int err = 0;
+       unsigned long total_size;
+
+       if (info->state != FBINFO_STATE_RUNNING)
+               return -EPERM;
+
+       total_size = info->screen_size;
+
+       if (total_size == 0)
+               total_size = info->fix.smem_len;
+
+       if (p >= total_size)
+               return 0;
+
+       if (count >= total_size)
+               count = total_size;
+
+       if (count + p > total_size)
+               count = total_size - p;
+
+       src = (void __force *)(info->screen_base + p);
+
+       if (info->fbops->fb_sync)
+               info->fbops->fb_sync(info);
+
+       if (copy_to_user(buf, src, count))
+               err = -EFAULT;
+
+       if  (!err)
+               *ppos += count;
+
+       return (err) ? err : count;
+}
+EXPORT_SYMBOL_GPL(fb_sys_read);
+
+ssize_t fb_sys_write(struct fb_info *info, const char __user *buf,
+                    size_t count, loff_t *ppos)
+{
+       unsigned long p = *ppos;
+       void *dst;
+       int err = 0;
+       unsigned long total_size;
+
+       if (info->state != FBINFO_STATE_RUNNING)
+               return -EPERM;
+
+       total_size = info->screen_size;
+
+       if (total_size == 0)
+               total_size = info->fix.smem_len;
+
+       if (p > total_size)
+               return -EFBIG;
+
+       if (count > total_size) {
+               err = -EFBIG;
+               count = total_size;
+       }
+
+       if (count + p > total_size) {
+               if (!err)
+                       err = -ENOSPC;
+
+               count = total_size - p;
+       }
+
+       dst = (void __force *) (info->screen_base + p);
+
+       if (info->fbops->fb_sync)
+               info->fbops->fb_sync(info);
+
+       if (copy_from_user(dst, buf, count))
+               err = -EFAULT;
+
+       if  (!err)
+               *ppos += count;
+
+       return (err) ? err : count;
+}
+EXPORT_SYMBOL_GPL(fb_sys_write);
+
+MODULE_AUTHOR("Antonino Daplas <adaplas@pol.net>");
+MODULE_DESCRIPTION("Generic file read (fb in system RAM)");
+MODULE_LICENSE("GPL");