From 00546598ba3c1a6d347cb7861ddcb28b2e8bcaad Mon Sep 17 00:00:00 2001
From: Daniel Vetter <daniel.vetter@ffwll.ch>
Date: Mon, 23 Mar 2020 15:49:23 +0100
Subject: drm: Manage drm_vblank_cleanup with drmm_
Git-commit: c23d686f1960a91006bfb4da1bb5edf88eef57c6
Patch-mainline: v5.8-rc1
References: jsc#SLE-12680, jsc#SLE-12880, jsc#SLE-12882, jsc#SLE-12883, jsc#SLE-13496, jsc#SLE-15322

Nothing special here, except that this is the first time that we
automatically clean up something that's initialized with an explicit
driver call. But the cleanup was done at the very end of the release
sequence for all drivers, and that's still the case. At least without
more uses of drmm_ through explicit driver calls.

Also for this one we need drmm_kcalloc, so lets add those.

The motivation here is to allow us to remove the explicit calls to
drm_dev_fini() from all drivers.

v2: Sort includes (Laurent)

v3: Motivate the change in the commit message better (Sam)

Acked-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200323144950.3018436-25-daniel.vetter@ffwll.ch
Signed-off-by: Patrik Jakobsson <pjakobsson@suse.de>
---
 drivers/gpu/drm/drm_drv.c      |  1 -
 drivers/gpu/drm/drm_internal.h |  1 -
 drivers/gpu/drm/drm_vblank.c   | 31 ++++++++++++-------------------
 include/drm/drm_managed.h      | 16 ++++++++++++++++
 4 files changed, 28 insertions(+), 21 deletions(-)

diff --git a/drivers/gpu/drm/drm_drv.c b/drivers/gpu/drm/drm_drv.c
index c6123849b721..c3da64676c6e 100644
--- a/drivers/gpu/drm/drm_drv.c
+++ b/drivers/gpu/drm/drm_drv.c
@@ -751,7 +751,6 @@ EXPORT_SYMBOL(devm_drm_dev_init);
  */
 void drm_dev_fini(struct drm_device *dev)
 {
-	drm_vblank_cleanup(dev);
 }
 EXPORT_SYMBOL(drm_dev_fini);
 
diff --git a/drivers/gpu/drm/drm_internal.h b/drivers/gpu/drm/drm_internal.h
index a40a0222419e..2470a352730b 100644
--- a/drivers/gpu/drm/drm_internal.h
+++ b/drivers/gpu/drm/drm_internal.h
@@ -94,7 +94,6 @@ 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);
 
 /* IOCTLS */
 int drm_wait_vblank_ioctl(struct drm_device *dev, void *data,
diff --git a/drivers/gpu/drm/drm_vblank.c b/drivers/gpu/drm/drm_vblank.c
index da7b0b0c1090..bcf346b3e486 100644
--- a/drivers/gpu/drm/drm_vblank.c
+++ b/drivers/gpu/drm/drm_vblank.c
@@ -30,6 +30,7 @@
 #include <drm/drm_crtc.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_framebuffer.h>
+#include <drm/drm_managed.h>
 #include <drm/drm_modeset_helper_vtables.h>
 #include <drm/drm_print.h>
 #include <drm/drm_vblank.h>
@@ -425,14 +426,10 @@ static void vblank_disable_fn(struct timer_list *t)
 	spin_unlock_irqrestore(&dev->vbl_lock, irqflags);
 }
 
-void drm_vblank_cleanup(struct drm_device *dev)
+static void drm_vblank_init_release(struct drm_device *dev, void *ptr)
 {
 	unsigned int pipe;
 
-	/* Bail if the driver didn't call drm_vblank_init() */
-	if (dev->num_crtcs == 0)
-		return;
-
 	for (pipe = 0; pipe < dev->num_crtcs; pipe++) {
 		struct drm_vblank_crtc *vblank = &dev->vblank[pipe];
 
@@ -441,10 +438,6 @@ void drm_vblank_cleanup(struct drm_device *dev)
 
 		del_timer_sync(&vblank->disable_timer);
 	}
-
-	kfree(dev->vblank);
-
-	dev->num_crtcs = 0;
 }
 
 /**
@@ -453,25 +446,29 @@ void drm_vblank_cleanup(struct drm_device *dev)
  * @num_crtcs: number of CRTCs supported by @dev
  *
  * This function initializes vblank support for @num_crtcs display pipelines.
- * Cleanup is handled by the DRM core, or through calling drm_dev_fini() for
- * drivers with a &drm_driver.release callback.
+ * Cleanup is handled automatically through a cleanup function added with
+ * drmm_add_action().
  *
  * Returns:
  * Zero on success or a negative error code on failure.
  */
 int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
 {
-	int ret = -ENOMEM;
+	int ret;
 	unsigned int i;
 
 	spin_lock_init(&dev->vbl_lock);
 	spin_lock_init(&dev->vblank_time_lock);
 
+	dev->vblank = drmm_kcalloc(dev, num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
+	if (!dev->vblank)
+		return -ENOMEM;
+
 	dev->num_crtcs = num_crtcs;
 
-	dev->vblank = kcalloc(num_crtcs, sizeof(*dev->vblank), GFP_KERNEL);
-	if (!dev->vblank)
-		goto err;
+	ret = drmm_add_action(dev, drm_vblank_init_release, NULL);
+	if (ret)
+		return ret;
 
 	for (i = 0; i < num_crtcs; i++) {
 		struct drm_vblank_crtc *vblank = &dev->vblank[i];
@@ -486,10 +483,6 @@ int drm_vblank_init(struct drm_device *dev, unsigned int num_crtcs)
 	DRM_INFO("Supports vblank timestamp caching Rev 2 (21.10.2013).\n");
 
 	return 0;
-
-err:
-	dev->num_crtcs = 0;
-	return ret;
 }
 EXPORT_SYMBOL(drm_vblank_init);
 
diff --git a/include/drm/drm_managed.h b/include/drm/drm_managed.h
index 2d1e29a2200c..191d8d206ff4 100644
--- a/include/drm/drm_managed.h
+++ b/include/drm/drm_managed.h
@@ -4,6 +4,7 @@
 #define _DRM_MANAGED_H_
 
 #include <linux/gfp.h>
+#include <linux/overflow.h>
 #include <linux/types.h>
 
 struct drm_device;
@@ -31,6 +32,21 @@ static inline void *drmm_kzalloc(struct drm_device *dev, size_t size, gfp_t gfp)
 {
 	return drmm_kmalloc(dev, size, gfp | __GFP_ZERO);
 }
+static inline void *drmm_kmalloc_array(struct drm_device *dev,
+				       size_t n, size_t size, gfp_t flags)
+{
+	size_t bytes;
+
+	if (unlikely(check_mul_overflow(n, size, &bytes)))
+		return NULL;
+
+	return drmm_kmalloc(dev, bytes, flags);
+}
+static inline void *drmm_kcalloc(struct drm_device *dev,
+				 size_t n, size_t size, gfp_t flags)
+{
+	return drmm_kmalloc_array(dev, n, size, flags | __GFP_ZERO);
+}
 char *drmm_kstrdup(struct drm_device *dev, const char *s, gfp_t gfp);
 
 void drmm_kfree(struct drm_device *dev, void *data);
-- 
2.28.0