drm: remove procfs code, take 2

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>
Signed-off-by: Dave Airlie <airlied@redhat.com>

1 files changed, 8 insertions, 24 deletions

diff --git a/drivers/gpu/drm/drm_stub.c b/drivers/gpu/drm/drm_stub.c
index 5edf938bbcc3..e30bb0d7c67a 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