4 files changed, 210 insertions, 4 deletions

diff --git a/drivers/gpu/drm/Makefile b/drivers/gpu/drm/Makefile
index 7f72ef5e7811..183c60048307 100644
--- a/drivers/gpu/drm/Makefile
+++ b/drivers/gpu/drm/Makefile
@@ -17,7 +17,8 @@ drm-y       :=	drm_auth.o drm_cache.o \
 		drm_plane.o drm_color_mgmt.o drm_print.o \
 		drm_dumb_buffers.o drm_mode_config.o drm_vblank.o \
 		drm_syncobj.o drm_lease.o drm_writeback.o drm_client.o \
-		drm_client_modeset.o drm_atomic_uapi.o drm_hdcp.o
+		drm_client_modeset.o drm_atomic_uapi.o drm_hdcp.o \
+		drm_managed.o
 
 drm-$(CONFIG_DRM_LEGACY) += drm_legacy_misc.o drm_bufs.o drm_context.o drm_dma.o drm_scatter.o drm_lock.o
 drm-$(CONFIG_DRM_LIB_RANDOM) += lib/drm_random.o
diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index 65a0acb79323..a1884005d983 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -629,6 +629,9 @@ int drm_dev_init(struct drm_device *dev,
 	dev->dev = get_device(parent);
 	dev->driver = driver;
 
+	INIT_LIST_HEAD(&dev->managed.resources);
+	spin_lock_init(&dev->managed.lock);
+
 	/* no per-device feature limits by default */
 	dev->driver_features = ~0u;
 
@@ -824,12 +827,18 @@ static void drm_dev_release(struct kref *ref)
 {
 	struct drm_device *dev = container_of(ref, struct drm_device, ref);
 
-	if (dev->driver->release) {
+	if (dev->driver->release)
 		dev->driver->release(dev);
-	} else {
+	else
 		drm_dev_fini(dev);
+
+	drm_managed_release(dev);
+
+	if (!dev->driver->release && !dev->managed.final_kfree) {
+		WARN_ON(!list_empty(&dev->managed.resources));
 		kfree(dev);
-	}
+	} else if (dev->managed.final_kfree)
+		kfree(dev->managed.final_kfree);
 }
 
 /**
diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
index 8b9e8bbca9b1..23ba15773097 100644
--- a/drivers/gpu/drm/drm_internal.h
+++ b/drivers/gpu/drm/drm_internal.h
@@ -89,6 +89,9 @@ void drm_prime_remove_buf_handle_locked(struct drm_prime_file_private *prime_fpr
 struct drm_minor *drm_minor_acquire(unsigned int minor_id);
 void drm_minor_release(struct drm_minor *minor);
 
+/* drm_managed.c */
+void drm_managed_release(struct drm_device *dev);
+
 /* drm_vblank.c */
 void drm_vblank_disable_and_save(struct drm_device *dev, unsigned int pipe);
 void drm_vblank_cleanup(struct drm_device *dev);
diff --git a/drivers/gpu/drm/drm_managed.c b/drivers/gpu/drm/drm_managed.c
new file mode 100644
index 000000000000..46d679b66e4d
--- /dev/null
+++ b/drivers/gpu/drm/drm_managed.c
@@ -0,0 +1,193 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020 Intel
+ *
+ * Based on drivers/base/devres.c
+ */
+
+#include <drm/drm_managed.h>
+
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/spinlock.h>
+
+#include <drm/drm_device.h>
+#include <drm/drm_print.h>
+
+/**
+ * DOC: managed resources
+ *
+ * Inspired by struct &device managed resources, but tied to the lifetime of
+ * struct &drm_device, which can outlive the underlying physical device, usually
+ * when userspace has some open files and other handles to resources still open.
+ */
+struct drmres_node {
+	struct list_head	entry;
+	drmres_release_t	release;
+	const char		*name;
+	size_t			size;
+};
+
+struct drmres {
+	struct drmres_node		node;
+	/*
+	 * Some archs want to perform DMA into kmalloc caches
+	 * and need a guaranteed alignment larger than
+	 * the alignment of a 64-bit integer.
+	 * Thus we use ARCH_KMALLOC_MINALIGN here and get exactly the same
+	 * buffer alignment as if it was allocated by plain kmalloc().
+	 */
+	u8 __aligned(ARCH_KMALLOC_MINALIGN) data[];
+};
+
+static void free_dr(struct drmres *dr)
+{
+	kfree_const(dr->node.name);
+	kfree(dr);
+}
+
+void drm_managed_release(struct drm_device *dev)
+{
+	struct drmres *dr, *tmp;
+
+	drm_dbg_drmres(dev, "drmres release begin\n");
+	list_for_each_entry_safe(dr, tmp, &dev->managed.resources, node.entry) {
+		drm_dbg_drmres(dev, "REL %p %s (%zu bytes)\n",
+			       dr, dr->node.name, dr->node.size);
+
+		if (dr->node.release)
+			dr->node.release(dev, dr->node.size ? *(void **)&dr->data : NULL);
+
+		list_del(&dr->node.entry);
+		free_dr(dr);
+	}
+	drm_dbg_drmres(dev, "drmres release end\n");
+}
+
+/*
+ * Always inline so that kmalloc_track_caller tracks the actual interesting
+ * caller outside of drm_managed.c.
+ */
+static __always_inline struct drmres * alloc_dr(drmres_release_t release,
+						size_t size, gfp_t gfp, int nid)
+{
+	size_t tot_size;
+	struct drmres *dr;
+
+	/* We must catch any near-SIZE_MAX cases that could overflow. */
+	if (unlikely(check_add_overflow(sizeof(*dr), size, &tot_size)))
+		return NULL;
+
+	dr = kmalloc_node_track_caller(tot_size, gfp, nid);
+	if (unlikely(!dr))
+		return NULL;
+
+	memset(dr, 0, offsetof(struct drmres, data));
+
+	INIT_LIST_HEAD(&dr->node.entry);
+	dr->node.release = release;
+	dr->node.size = size;
+
+	return dr;
+}
+
+static void del_dr(struct drm_device *dev, struct drmres *dr)
+{
+	list_del_init(&dr->node.entry);
+
+	drm_dbg_drmres(dev, "DEL %p %s (%lu bytes)\n",
+		       dr, dr->node.name, (unsigned long) dr->node.size);
+}
+
+static void add_dr(struct drm_device *dev, struct drmres *dr)
+{
+	unsigned long flags;
+
+	spin_lock_irqsave(&dev->managed.lock, flags);
+	list_add(&dr->node.entry, &dev->managed.resources);
+	spin_unlock_irqrestore(&dev->managed.lock, flags);
+
+	drm_dbg_drmres(dev, "ADD %p %s (%lu bytes)\n",
+		       dr, dr->node.name, (unsigned long) dr->node.size);
+}
+
+void drmm_add_final_kfree(struct drm_device *dev, void *container)
+{
+	WARN_ON(dev->managed.final_kfree);
+	WARN_ON(dev < (struct drm_device *) container);
+	WARN_ON(dev + 1 >=
+		(struct drm_device *) (container + ksize(container)));
+	dev->managed.final_kfree = container;
+}
+EXPORT_SYMBOL(drmm_add_final_kfree);
+
+int __drmm_add_action(struct drm_device *dev,
+		      drmres_release_t action,
+		      void *data, const char *name)
+{
+	struct drmres *dr;
+	void **void_ptr;
+
+	dr = alloc_dr(action, data ? sizeof(void*) : 0,
+		      GFP_KERNEL | __GFP_ZERO,
+		      dev_to_node(dev->dev));
+	if (!dr) {
+		drm_dbg_drmres(dev, "failed to add action %s for %p\n",
+			       name, data);
+		return -ENOMEM;
+	}
+
+	dr->node.name = kstrdup_const(name, GFP_KERNEL);
+	if (data) {
+		void_ptr = (void **)&dr->data;
+		*void_ptr = data;
+	}
+
+	add_dr(dev, dr);
+
+	return 0;
+}
+EXPORT_SYMBOL(__drmm_add_action);
+
+void *drmm_kmalloc(struct drm_device *dev, size_t size, gfp_t gfp)
+{
+	struct drmres *dr;
+
+	dr = alloc_dr(NULL, size, gfp, dev_to_node(dev->dev));
+	if (!dr) {
+		drm_dbg_drmres(dev, "failed to allocate %zu bytes, %u flags\n",
+			       size, gfp);
+		return NULL;
+	}
+	dr->node.name = kstrdup_const("kmalloc", GFP_KERNEL);
+
+	add_dr(dev, dr);
+
+	return dr->data;
+}
+EXPORT_SYMBOL(drmm_kmalloc);
+
+void drmm_kfree(struct drm_device *dev, void *data)
+{
+	struct drmres *dr_match = NULL, *dr;
+	unsigned long flags;
+
+	if (!data)
+		return;
+
+	spin_lock_irqsave(&dev->managed.lock, flags);
+	list_for_each_entry(dr, &dev->managed.resources, node.entry) {
+		if (dr->data == data) {
+			dr_match = dr;
+			del_dr(dev, dr_match);
+			break;
+		}
+	}
+	spin_unlock_irqrestore(&dev->managed.lock, flags);
+
+	if (WARN_ON(!dr_match))
+		return;
+
+	free_dr(dr_match);
+}
+EXPORT_SYMBOL(drmm_kfree);