drm: Convert proc files to seq_file and introduce debugfs

The old mechanism to formatting proc files is extremely ugly. The
seq_file API was designed specifically for cases like this and greatly
simplifies the process.

Also, most of the files in /proc really don't belong there. This patch
introduces the infrastructure for putting these into debugfs and exposes
all of the proc files in debugfs as well.

Signed-off-by: Ben Gamari <bgamari@gmail.com>
Signed-off-by: Eric Anholt <eric@anholt.net>
diff --git a/drivers/gpu/drm/drm_debugfs.c b/drivers/gpu/drm/drm_debugfs.c
new file mode 100644
index 0000000..c77c6c6
--- /dev/null
+++ b/drivers/gpu/drm/drm_debugfs.c
@@ -0,0 +1,235 @@
+/**
+ * \file drm_debugfs.c
+ * debugfs support for DRM
+ *
+ * \author Ben Gamari <bgamari@gmail.com>
+ */
+
+/*
+ * Created: Sun Dec 21 13:08:50 2008 by bgamari@gmail.com
+ *
+ * Copyright 2008 Ben Gamari <bgamari@gmail.com>
+ *
+ * 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
+ * VA LINUX SYSTEMS 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.
+ */
+
+#include <linux/debugfs.h>
+#include <linux/seq_file.h>
+#include "drmP.h"
+
+#if defined(CONFIG_DEBUG_FS)
+
+/***************************************************
+ * Initialization, etc.
+ **************************************************/
+
+static struct drm_info_list drm_debugfs_list[] = {
+	{"name", drm_name_info, 0},
+	{"vm", drm_vm_info, 0},
+	{"clients", drm_clients_info, 0},
+	{"queues", drm_queues_info, 0},
+	{"bufs", drm_bufs_info, 0},
+	{"gem_names", drm_gem_name_info, DRIVER_GEM},
+	{"gem_objects", drm_gem_object_info, DRIVER_GEM},
+#if DRM_DEBUG_CODE
+	{"vma", drm_vma_info, 0},
+#endif
+};
+#define DRM_DEBUGFS_ENTRIES ARRAY_SIZE(drm_debugfs_list)
+
+
+static int drm_debugfs_open(struct inode *inode, struct file *file)
+{
+	struct drm_info_node *node = inode->i_private;
+
+	return single_open(file, node->info_ent->show, node);
+}
+
+
+static const struct file_operations drm_debugfs_fops = {
+	.owner = THIS_MODULE,
+	.open = drm_debugfs_open,
+	.read = seq_read,
+	.llseek = seq_lseek,
+	.release = single_release,
+};
+
+
+/**
+ * Initialize a given set of debugfs files for a device
+ *
+ * \param files The array of files to create
+ * \param count The number of files given
+ * \param root DRI debugfs dir entry.
+ * \param minor device minor number
+ * \return Zero on success, non-zero on failure
+ *
+ * Create a given set of debugfs files represented by an array of
+ * gdm_debugfs_lists in the given root directory.
+ */
+int drm_debugfs_create_files(struct drm_info_list *files, int count,
+			     struct dentry *root, struct drm_minor *minor)
+{
+	struct drm_device *dev = minor->dev;
+	struct dentry *ent;
+	struct drm_info_node *tmp;
+	char name[64];
+	int i, ret;
+
+	for (i = 0; i < count; i++) {
+		u32 features = files[i].driver_features;
+
+		if (features != 0 &&
+		    (dev->driver->driver_features & features) != features)
+			continue;
+
+		tmp = drm_alloc(sizeof(struct drm_info_node),
+				_DRM_DRIVER);
+		ent = debugfs_create_file(files[i].name, S_IFREG | S_IRUGO,
+					  root, tmp, &drm_debugfs_fops);
+		if (!ent) {
+			DRM_ERROR("Cannot create /debugfs/dri/%s/%s\n",
+				  name, files[i].name);
+			drm_free(tmp, sizeof(struct drm_info_node),
+				 _DRM_DRIVER);
+			ret = -1;
+			goto fail;
+		}
+
+		tmp->minor = minor;
+		tmp->dent = ent;
+		tmp->info_ent = &files[i];
+		list_add(&(tmp->list), &(minor->debugfs_nodes.list));
+	}
+	return 0;
+
+fail:
+	drm_debugfs_remove_files(files, count, minor);
+	return ret;
+}
+EXPORT_SYMBOL(drm_debugfs_create_files);
+
+/**
+ * Initialize the DRI debugfs filesystem for a device
+ *
+ * \param dev DRM device
+ * \param minor device minor number
+ * \param root DRI debugfs dir entry.
+ *
+ * Create the DRI debugfs root entry "/debugfs/dri", the device debugfs root entry
+ * "/debugfs/dri/%minor%/", and each entry in debugfs_list as
+ * "/debugfs/dri/%minor%/%name%".
+ */
+int drm_debugfs_init(struct drm_minor *minor, int minor_id,
+		     struct dentry *root)
+{
+	struct drm_device *dev = minor->dev;
+	char name[64];
+	int ret;
+
+	INIT_LIST_HEAD(&minor->debugfs_nodes.list);
+	sprintf(name, "%d", minor_id);
+	minor->debugfs_root = debugfs_create_dir(name, root);
+	if (!minor->debugfs_root) {
+		DRM_ERROR("Cannot create /debugfs/dri/%s\n", name);
+		return -1;
+	}
+
+	ret = drm_debugfs_create_files(drm_debugfs_list, DRM_DEBUGFS_ENTRIES,
+				       minor->debugfs_root, minor);
+	if (ret) {
+		debugfs_remove(minor->debugfs_root);
+		minor->debugfs_root = NULL;
+		DRM_ERROR("Failed to create core drm debugfs files\n");
+		return ret;
+	}
+
+	if (dev->driver->debugfs_init) {
+		ret = dev->driver->debugfs_init(minor);
+		if (ret) {
+			DRM_ERROR("DRM: Driver failed to initialize "
+				  "/debugfs/dri.\n");
+			return ret;
+		}
+	}
+	return 0;
+}
+
+
+/**
+ * Remove a list of debugfs files
+ *
+ * \param files The list of files
+ * \param count The number of files
+ * \param minor The minor of which we should remove the files
+ * \return always zero.
+ *
+ * Remove all debugfs entries created by debugfs_init().
+ */
+int drm_debugfs_remove_files(struct drm_info_list *files, int count,
+			     struct drm_minor *minor)
+{
+	struct list_head *pos, *q;
+	struct drm_info_node *tmp;
+	int i;
+
+	for (i = 0; i < count; i++) {
+		list_for_each_safe(pos, q, &minor->debugfs_nodes.list) {
+			tmp = list_entry(pos, struct drm_info_node, list);
+			if (tmp->info_ent == &files[i]) {
+				debugfs_remove(tmp->dent);
+				list_del(pos);
+				drm_free(tmp, sizeof(struct drm_info_node),
+					 _DRM_DRIVER);
+			}
+		}
+	}
+	return 0;
+}
+EXPORT_SYMBOL(drm_debugfs_remove_files);
+
+/**
+ * Cleanup the debugfs filesystem resources.
+ *
+ * \param minor device minor number.
+ * \return always zero.
+ *
+ * Remove all debugfs entries created by debugfs_init().
+ */
+int drm_debugfs_cleanup(struct drm_minor *minor)
+{
+	struct drm_device *dev = minor->dev;
+
+	if (!minor->debugfs_root)
+		return 0;
+
+	if (dev->driver->debugfs_cleanup)
+		dev->driver->debugfs_cleanup(minor);
+
+	drm_debugfs_remove_files(drm_debugfs_list, DRM_DEBUGFS_ENTRIES, minor);
+
+	debugfs_remove(minor->debugfs_root);
+	minor->debugfs_root = NULL;
+
+	return 0;
+}
+
+#endif /* CONFIG_DEBUG_FS */
+