patch-2.3.18 linux/drivers/char/drm/fops.c

• Lines: 205
• Date: Tue Sep 7 14:51:28 1999
• Orig file: v2.3.17/linux/drivers/char/drm/fops.c
• Orig date: Wed Dec 31 16:00:00 1969

diff -u --recursive --new-file v2.3.17/linux/drivers/char/drm/fops.c linux/drivers/char/drm/fops.c
@@ -0,0 +1,204 @@
+/* fops.c -- File operations for DRM -*- linux-c -*-
+ * Created: Mon Jan  4 08:58:31 1999 by faith@precisioninsight.com
+ * Revised: Fri Aug 20 11:31:46 1999 by faith@precisioninsight.com
+ *
+ * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ * 
+ * The above copyright notice and this permission notice (including the next
+ * paragraph) shall be included in all copies or substantial portions of the
+ * Software.
+ * 
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * PRECISION INSIGHT AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ * 
+ * $PI: xc/programs/Xserver/hw/xfree86/os-support/linux/drm/generic/fops.c,v 1.3 1999/08/20 15:36:45 faith Exp $
+ * $XFree86$
+ *
+ */
+
+#define __NO_VERSION__
+#include "drmP.h"
+
+/* drm_open is called whenever a process opens /dev/drm. */
+
+int drm_open_helper(struct inode *inode, struct file *filp, drm_device_t *dev)
+{
+	kdev_t	     minor = MINOR(inode->i_rdev);
+	drm_file_t   *priv;
+
+	if (filp->f_flags & O_EXCL)   return -EBUSY; /* No exclusive opens */
+
+	DRM_DEBUG("pid = %d, minor = %d\n", current->pid, minor);
+
+	priv		    = drm_alloc(sizeof(*priv), DRM_MEM_FILES);
+	memset(priv, 0, sizeof(*priv));
+	filp->private_data  = priv;
+	priv->uid	    = current->euid;
+	priv->pid	    = current->pid;
+	priv->minor	    = minor;
+	priv->dev	    = dev;
+	priv->ioctl_count   = 0;
+	priv->authenticated = capable(CAP_SYS_ADMIN);
+
+	down(&dev->struct_sem);
+	if (!dev->file_last) {
+		priv->next	= NULL;
+		priv->prev	= NULL;
+		dev->file_first = priv;
+		dev->file_last	= priv;
+	} else {
+		priv->next	     = NULL;
+		priv->prev	     = dev->file_last;
+		dev->file_last->next = priv;
+		dev->file_last	     = priv;
+	}
+	up(&dev->struct_sem);
+	
+	return 0;
+}
+
+int drm_flush(struct file *filp)
+{
+	drm_file_t    *priv   = filp->private_data;
+	drm_device_t  *dev    = priv->dev;
+
+	DRM_DEBUG("pid = %d, device = 0x%x, open_count = %d, f_count = %d\n",
+		  current->pid, dev->device, dev->open_count, filp->f_count);
+	return 0;
+}
+
+/* drm_release is called whenever a process closes /dev/drm*.  Linux calls
+   this only if any mappings have been closed. */
+
+int drm_release(struct inode *inode, struct file *filp)
+{
+	drm_file_t    *priv   = filp->private_data;
+	drm_device_t  *dev    = priv->dev;
+
+	DRM_DEBUG("pid = %d, device = 0x%x, open_count = %d\n",
+		  current->pid, dev->device, dev->open_count);
+
+	drm_reclaim_buffers(dev, priv->pid);
+
+	drm_fasync(-1, filp, 0);
+
+	down(&dev->struct_sem);
+	if (priv->prev) priv->prev->next = priv->next;
+	else		dev->file_first	 = priv->next;
+	if (priv->next) priv->next->prev = priv->prev;
+	else		dev->file_last	 = priv->prev;
+	up(&dev->struct_sem);
+	
+	drm_free(priv, sizeof(*priv), DRM_MEM_FILES);
+	
+	return 0;
+}
+
+int drm_fasync(int fd, struct file *filp, int on)
+{
+	drm_file_t    *priv   = filp->private_data;
+	drm_device_t  *dev    = priv->dev;
+	int	      retcode;
+	
+	DRM_DEBUG("fd = %d, device = 0x%x\n", fd, dev->device);
+	retcode = fasync_helper(fd, filp, on, &dev->buf_async);
+	if (retcode < 0) return retcode;
+	return 0;
+}
+
+
+/* The drm_read and drm_write_string code (especially that which manages
+   the circular buffer), is based on Alessandro Rubini's LINUX DEVICE
+   DRIVERS (Cambridge: O'Reilly, 1998), pages 111-113. */
+
+ssize_t drm_read(struct file *filp, char *buf, size_t count, loff_t *off)
+{
+	drm_file_t    *priv   = filp->private_data;
+	drm_device_t  *dev    = priv->dev;
+	int	      left;
+	int	      avail;
+	int	      send;
+	int	      cur;
+
+	DRM_DEBUG("%p, %p\n", dev->buf_rp, dev->buf_wp);
+	
+	while (dev->buf_rp == dev->buf_wp) {
+		DRM_DEBUG("  sleeping\n");
+		if (filp->f_flags & O_NONBLOCK) {
+			return -EAGAIN;
+		}
+		interruptible_sleep_on(&dev->buf_readers);
+		if (signal_pending(current)) {
+			DRM_DEBUG("  interrupted\n");
+			return -ERESTARTSYS;
+		}
+		DRM_DEBUG("  awake\n");
+	}
+
+	left  = (dev->buf_rp + DRM_BSZ - dev->buf_wp) % DRM_BSZ;
+	avail = DRM_BSZ - left;
+	send  = DRM_MIN(avail, count);
+
+	while (send) {
+		if (dev->buf_wp > dev->buf_rp) {
+			cur = DRM_MIN(send, dev->buf_wp - dev->buf_rp);
+		} else {
+			cur = DRM_MIN(send, dev->buf_end - dev->buf_rp);
+		}
+		copy_to_user_ret(buf, dev->buf_rp, cur, -EINVAL);
+		dev->buf_rp += cur;
+		if (dev->buf_rp == dev->buf_end) dev->buf_rp = dev->buf;
+		send -= cur;
+	}
+	
+	wake_up_interruptible(&dev->buf_writers);
+	return DRM_MIN(avail, count);;
+}
+
+int drm_write_string(drm_device_t *dev, const char *s)
+{
+	int left   = (dev->buf_rp + DRM_BSZ - dev->buf_wp) % DRM_BSZ;
+	int send   = strlen(s);
+	int count;
+
+	DRM_DEBUG("%d left, %d to send (%p, %p)\n",
+		  left, send, dev->buf_rp, dev->buf_wp);
+	
+	if (left == 1 || dev->buf_wp != dev->buf_rp) {
+		DRM_ERROR("Buffer not empty (%d left, wp = %p, rp = %p)\n",
+			  left,
+			  dev->buf_wp,
+			  dev->buf_rp);
+	}
+
+	while (send) {
+		if (dev->buf_wp >= dev->buf_rp) {
+			count = DRM_MIN(send, dev->buf_end - dev->buf_wp);
+			if (count == left) --count; /* Leave a hole */
+		} else {
+			count = DRM_MIN(send, dev->buf_rp - dev->buf_wp - 1);
+		}
+		strncpy(dev->buf_wp, s, count);
+		dev->buf_wp += count;
+		if (dev->buf_wp == dev->buf_end) dev->buf_wp = dev->buf;
+		send -= count;
+	}
+
+	if (dev->buf_async) kill_fasync(dev->buf_async, SIGIO);
+	DRM_DEBUG("waking\n");
+	wake_up_interruptible(&dev->buf_readers);
+	return 0;
+}