[PATCH 24/25] drm: remove procfs code, take 2

[Daniel Vetter <daniel.vetter@ffwll.ch>]

So almost two years ago I've tried to nuke the procfs code already
once before:

http://lists.freedesktop.org/archives/dri-devel/2011-October/015707.html

The conclusion was that userspace drivers (specifically libdrm device
node detection) stopped relying on procfs in 2001. But after some
digging it turned out that the drmstat tool in libdrm is still using
those files (but only when certain options are set). So we've decided
to keep profcs.

But I when I've started to dig around again what exactly this tool
does I've noticed that it tries to read the "mem", "vm", and "vma"
files from procfs. Now as far my git history digging shows "mem" never
did anything useful (at least in the version that first showed up in
upstream history in 2004) and the file was remove in

commit 955b12def42e83287c1bdb1411d99451753c1391
Author: Ben Gamari <bgamari@gmail.com>
Date:   Tue Feb 17 20:08:49 2009 -0500

    drm: Convert proc files to seq_file and introduce debugfs

Which means that for over 4 years drmstat has been broken, and no one
cared. In my opinion that's proof enough that no one is actually using
drmstat, and so that we can savely nuke the procfs support from drm.

While at it fix up the error case cleanup for debugfs in drm_get_minor.

v2: Fix dates, libdrm stopped relying on procfs for drm node detection
in 2001.

v3: fixup compilation warning for !CONFIG_DEBUG_FS, reported by
Fengguang Wu.

Cc: kbuild test robot <fengguang.wu@intel.com>
Cc: Dave Airlie <airlied@linux.ie>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
---
 drivers/gpu/drm/Makefile   |   2 +-
 drivers/gpu/drm/drm_drv.c  |   8 --
 drivers/gpu/drm/drm_proc.c | 209 ---------------------------------------------
 drivers/gpu/drm/drm_stub.c |  32 ++-----
 include/drm/drmP.h         |   8 --
 5 files changed, 9 insertions(+), 250 deletions(-)
 delete mode 100644 drivers/gpu/drm/drm_proc.c

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index d943b94..55af865 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -7,7 +7,7 @@ ccflags-y := -Iinclude/drm
 drm-y       :=	drm_auth.o drm_buffer.o drm_bufs.o drm_cache.o \
 		drm_context.o drm_dma.o \
 		drm_drv.o drm_fops.o drm_gem.o drm_ioctl.o drm_irq.o \
-		drm_lock.o drm_memory.o drm_proc.o drm_stub.o drm_vm.o \
+		drm_lock.o drm_memory.o drm_stub.o drm_vm.o \
 		drm_agpsupport.o drm_scatter.o drm_pci.o \
 		drm_platform.o drm_sysfs.o drm_hashtab.o drm_mm.o \
 		drm_crtc.o drm_modes.o drm_edid.o \
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 83078cd..a845f31 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -237,13 +237,6 @@ static int __init drm_core_init(void)
 		goto err_p2;
 	}
 
-	drm_proc_root = proc_mkdir("dri", NULL);
-	if (!drm_proc_root) {
-		DRM_ERROR("Cannot create /proc/dri\n");
-		ret = -1;
-		goto err_p3;
-	}
-
 	drm_debugfs_root = debugfs_create_dir("dri", NULL);
 	if (!drm_debugfs_root) {
 		DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
@@ -266,7 +259,6 @@ err_p1:
 
 static void __exit drm_core_exit(void)
 {
-	remove_proc_entry("dri", NULL);
 	debugfs_remove(drm_debugfs_root);
 	drm_sysfs_destroy();
 
diff --git a/drivers/gpu/drm/drm_proc.c b/drivers/gpu/drm/drm_proc.c
deleted file mode 100644
index d7f2324..0000000
--- a/drivers/gpu/drm/drm_proc.c
+++ /dev/null
@@ -1,209 +0,0 @@
-/**
- * \file drm_proc.c
- * /proc support for DRM
- *
- * \author Rickard E. (Rik) Faith <faith@valinux.com>
- * \author Gareth Hughes <gareth@valinux.com>
- *
- * \par Acknowledgements:
- *    Matthew J Sottek <matthew.j.sottek@intel.com> sent in a patch to fix
- *    the problem with the proc files not outputting all their information.
- */
-
-/*
- * Created: Mon Jan 11 09:48:47 1999 by faith@valinux.com
- *
- * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
- * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
- * 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
- * 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/seq_file.h>
-#include <linux/slab.h>
-#include <linux/export.h>
-#include <drm/drmP.h>
-
-/***************************************************
- * Initialization, etc.
- **************************************************/
-
-/**
- * Proc file list.
- */
-static const struct drm_info_list drm_proc_list[] = {
-	{"name", drm_name_info, 0},
-	{"vm", drm_vm_info, 0},
-	{"clients", drm_clients_info, 0},
-	{"bufs", drm_bufs_info, 0},
-	{"gem_names", drm_gem_name_info, DRIVER_GEM},
-#if DRM_DEBUG_CODE
-	{"vma", drm_vma_info, 0},
-#endif
-};
-#define DRM_PROC_ENTRIES ARRAY_SIZE(drm_proc_list)
-
-static int drm_proc_open(struct inode *inode, struct file *file)
-{
-	struct drm_info_node* node = PDE_DATA(inode);
-
-	return single_open(file, node->info_ent->show, node);
-}
-
-static const struct file_operations drm_proc_fops = {
-	.owner = THIS_MODULE,
-	.open = drm_proc_open,
-	.read = seq_read,
-	.llseek = seq_lseek,
-	.release = single_release,
-};
-
-
-/**
- * Initialize a given set of proc files for a device
- *
- * \param files The array of files to create
- * \param count The number of files given
- * \param root DRI proc dir entry.
- * \param minor device minor number
- * \return Zero on success, non-zero on failure
- *
- * Create a given set of proc files represented by an array of
- * gdm_proc_lists in the given root directory.
- */
-static int drm_proc_create_files(const struct drm_info_list *files, int count,
-			  struct proc_dir_entry *root, struct drm_minor *minor)
-{
-	struct drm_device *dev = minor->dev;
-	struct proc_dir_entry *ent;
-	struct drm_info_node *tmp;
-	int i;
-
-	for (i = 0; i < count; i++) {
-		u32 features = files[i].driver_features;
-
-		if (features != 0 &&
-		    (dev->driver->driver_features & features) != features)
-			continue;
-
-		tmp = kmalloc(sizeof(struct drm_info_node), GFP_KERNEL);
-		if (!tmp)
-			return -1;
-
-		tmp->minor = minor;
-		tmp->info_ent = &files[i];
-		list_add(&tmp->list, &minor->proc_nodes.list);
-
-		ent = proc_create_data(files[i].name, S_IRUGO, root,
-				       &drm_proc_fops, tmp);
-		if (!ent) {
-			DRM_ERROR("Cannot create /proc/dri/%u/%s\n",
-				  minor->index, files[i].name);
-			list_del(&tmp->list);
-			kfree(tmp);
-			return -1;
-		}
-	}
-	return 0;
-}
-
-/**
- * Initialize the DRI proc filesystem for a device
- *
- * \param dev DRM device
- * \param root DRI proc dir entry.
- * \param dev_root resulting DRI device proc dir entry.
- * \return root entry pointer on success, or NULL on failure.
- *
- * Create the DRI proc root entry "/proc/dri", the device proc root entry
- * "/proc/dri/%minor%/", and each entry in proc_list as
- * "/proc/dri/%minor%/%name%".
- */
-int drm_proc_init(struct drm_minor *minor, struct proc_dir_entry *root)
-{
-	char name[12];
-	int ret;
-
-	INIT_LIST_HEAD(&minor->proc_nodes.list);
-	sprintf(name, "%u", minor->index);
-	minor->proc_root = proc_mkdir(name, root);
-	if (!minor->proc_root) {
-		DRM_ERROR("Cannot create /proc/dri/%s\n", name);
-		return -1;
-	}
-
-	ret = drm_proc_create_files(drm_proc_list, DRM_PROC_ENTRIES,
-				    minor->proc_root, minor);
-	if (ret) {
-		remove_proc_subtree(name, root);
-		minor->proc_root = NULL;
-		DRM_ERROR("Failed to create core drm proc files\n");
-		return ret;
-	}
-
-	return 0;
-}
-
-static int drm_proc_remove_files(const 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->proc_nodes.list) {
-			tmp = list_entry(pos, struct drm_info_node, list);
-			if (tmp->info_ent == &files[i]) {
-				remove_proc_entry(files[i].name,
-						  minor->proc_root);
-				list_del(pos);
-				kfree(tmp);
-			}
-		}
-	}
-	return 0;
-}
-
-/**
- * Cleanup the proc filesystem resources.
- *
- * \param minor device minor number.
- * \param root DRI proc dir entry.
- * \param dev_root DRI device proc dir entry.
- * \return always zero.
- *
- * Remove all proc entries created by proc_init().
- */
-int drm_proc_cleanup(struct drm_minor *minor, struct proc_dir_entry *root)
-{
-	char name[64];
-
-	if (!root || !minor->proc_root)
-		return 0;
-
-	drm_proc_remove_files(drm_proc_list, DRM_PROC_ENTRIES, minor);
-
-	sprintf(name, "%d", minor->index);
-	remove_proc_subtree(name, root);
-	return 0;
-}
-
diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index aa0664d..ea37c39 100644
--- a/drivers/gpu/drm/drm_stub.c
+++ b/drivers/gpu/drm/drm_stub.c
@@ -68,7 +68,6 @@ module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
 struct idr drm_minors_idr;
 
 struct class *drm_class;
-struct proc_dir_entry *drm_proc_root;
 struct dentry *drm_debugfs_root;
 
 int drm_err(const char *func, const char *format, ...)
@@ -315,9 +314,8 @@ EXPORT_SYMBOL(drm_fill_in_dev);
  * \param sec-minor structure to hold the assigned minor
  * \return negative number on failure.
  *
- * Search an empty entry and initialize it to the given parameters, and
- * create the proc init entry via proc_init(). This routines assigns
- * minor numbers to secondary heads of multi-headed cards
+ * Search an empty entry and initialize it to the given parameters. This
+ * routines assigns minor numbers to secondary heads of multi-headed cards
  */
 int drm_get_minor(struct drm_device *dev, struct drm_minor **minor, int type)
 {
@@ -345,20 +343,11 @@ int drm_get_minor(struct drm_device *dev, struct drm_minor **minor, int type)
 
 	idr_replace(&drm_minors_idr, new_minor, minor_id);
 
-	if (type == DRM_MINOR_LEGACY) {
-		ret = drm_proc_init(new_minor, drm_proc_root);
-		if (ret) {
-			DRM_ERROR("DRM: Failed to initialize /proc/dri.\n");
-			goto err_mem;
-		}
-	} else
-		new_minor->proc_root = NULL;
-
 #if defined(CONFIG_DEBUG_FS)
 	ret = drm_debugfs_init(new_minor, minor_id, drm_debugfs_root);
 	if (ret) {
 		DRM_ERROR("DRM: Failed to initialize /sys/kernel/debug/dri.\n");
-		goto err_g2;
+		goto err_mem;
 	}
 #endif
 
@@ -366,7 +355,7 @@ int drm_get_minor(struct drm_device *dev, struct drm_minor **minor, int type)
 	if (ret) {
 		printk(KERN_ERR
 		       "DRM: Error sysfs_device_add.\n");
-		goto err_g2;
+		goto err_debugfs;
 	}
 	*minor = new_minor;
 
@@ -374,10 +363,11 @@ int drm_get_minor(struct drm_device *dev, struct drm_minor **minor, int type)
 	return 0;
 
 
-err_g2:
-	if (new_minor->type == DRM_MINOR_LEGACY)
-		drm_proc_cleanup(new_minor, drm_proc_root);
+err_debugfs:
+#if defined(CONFIG_DEBUG_FS)
+	drm_debugfs_cleanup(new_minor);
 err_mem:
+#endif
 	kfree(new_minor);
 err_idr:
 	idr_remove(&drm_minors_idr, minor_id);
@@ -391,10 +381,6 @@ EXPORT_SYMBOL(drm_get_minor);
  *
  * \param sec_minor - structure to be released
  * \return always zero
- *
- * Cleans up the proc resources. Not legal for this to be the
- * last minor released.
- *
  */
 int drm_put_minor(struct drm_minor **minor_p)
 {
@@ -402,8 +388,6 @@ int drm_put_minor(struct drm_minor **minor_p)
 
 	DRM_DEBUG("release secondary minor %d\n", minor->index);
 
-	if (minor->type == DRM_MINOR_LEGACY)
-		drm_proc_cleanup(minor, drm_proc_root);
 #if defined(CONFIG_DEBUG_FS)
 	drm_debugfs_cleanup(minor);
 #endif
diff --git a/include/drm/drmP.h b/include/drm/drmP.h
index 2a2a5b7..46b3102 100644
--- a/include/drm/drmP.h
+++ b/include/drm/drmP.h
@@ -45,7 +45,6 @@
 #include <linux/kernel.h>
 #include <linux/miscdevice.h>
 #include <linux/fs.h>
-#include <linux/proc_fs.h>
 #include <linux/init.h>
 #include <linux/file.h>
 #include <linux/platform_device.h>
@@ -1020,8 +1019,6 @@ struct drm_minor {
 	struct device kdev;		/**< Linux device */
 	struct drm_device *dev;
 
-	struct proc_dir_entry *proc_root;  /**< proc directory entry */
-	struct drm_info_node proc_nodes;
 	struct dentry *debugfs_root;
 
 	struct list_head debugfs_list;
@@ -1474,17 +1471,12 @@ extern unsigned int drm_timestamp_precision;
 extern unsigned int drm_timestamp_monotonic;
 
 extern struct class *drm_class;
-extern struct proc_dir_entry *drm_proc_root;
 extern struct dentry *drm_debugfs_root;
 
 extern struct idr drm_minors_idr;
 
 extern struct drm_local_map *drm_getsarea(struct drm_device *dev);
 
-				/* Proc support (drm_proc.h) */
-extern int drm_proc_init(struct drm_minor *minor, struct proc_dir_entry *root);
-extern int drm_proc_cleanup(struct drm_minor *minor, struct proc_dir_entry *root);
-
 				/* Debugfs support */
 #if defined(CONFIG_DEBUG_FS)
 extern int drm_debugfs_init(struct drm_minor *minor, int minor_id,
-- 
1.8.3.2