[PATCH libdrm 8/9] amdgpu: Drop refcount member from struct amdgpu_core_bo/device

[Michel Dänzer]

From: Michel Dänzer <michel.daenzer at amd.com>

We can just walk the lists of struct amdgpu_bo/device to find out if
there are any references left.

Signed-off-by: Michel Dänzer <michel.daenzer at amd.com>
---
 amdgpu/amdgpu_bo.c       | 14 +++++++++++---
 amdgpu/amdgpu_device.c   | 30 ++++++++++++++++++++++--------
 amdgpu/amdgpu_internal.h |  2 --
 3 files changed, 33 insertions(+), 13 deletions(-)

diff --git a/amdgpu/amdgpu_bo.c b/amdgpu/amdgpu_bo.c
index f40df484..332ce4be 100644
--- a/amdgpu/amdgpu_bo.c
+++ b/amdgpu/amdgpu_bo.c
@@ -65,7 +65,6 @@ static int amdgpu_core_bo_create(struct amdgpu_core_device *dev,
 		return r;
 	}
 
-	bo->refcount = 1;
 	bo->alloc_size = size;
 	bo->handle = handle;
 	pthread_mutex_init(&bo->cpu_access_mutex, NULL);
@@ -95,7 +94,6 @@ static int amdgpu_bo_create(amdgpu_device_handle user_dev,
 				goto out;
 			}
 		}
-		bo->refcount++;
 	} else {
 		r = amdgpu_core_bo_create(dev, size, handle, &bo);
 		if (r)
@@ -466,8 +464,18 @@ static void amdgpu_core_bo_free(struct amdgpu_bo *user_bo)
 {
 	struct amdgpu_core_device *dev = user_bo->dev->core;
 	struct amdgpu_core_bo *bo = user_bo->core;
+	struct amdgpu_bo *iter_bo;
 
-	if (--bo->refcount == 0) {
+	/* Are there any other user BOs left referencing the same core BO? */
+	for (iter_bo = bo->user_bos; iter_bo; iter_bo = iter_bo->next) {
+		if (iter_bo == user_bo)
+			continue;
+
+		if (iter_bo->core == bo)
+			break;
+	}
+
+	if (!iter_bo) {
 		/* Remove the buffer from the hash tables. */
 		handle_table_remove(&dev->bo_handles, bo->handle);
 
diff --git a/amdgpu/amdgpu_device.c b/amdgpu/amdgpu_device.c
index 8a99b8bb..1709099e 100644
--- a/amdgpu/amdgpu_device.c
+++ b/amdgpu/amdgpu_device.c
@@ -72,9 +72,6 @@ static int fd_compare(int fd1, int fd2)
 
 static void amdgpu_device_free(struct amdgpu_core_device *dev)
 {
-	if (--dev->refcount > 0)
-		return;
-
 	close(dev->fd);
 
 	amdgpu_vamgr_deinit(&dev->vamgr_32);
@@ -102,6 +99,26 @@ static bool same_file_description(int fd1, int fd2)
 	return fd1 == fd2;
 }
 
+static void amdgpu_device_unreference(amdgpu_device_handle user_dev)
+{
+	struct amdgpu_device *dev;
+
+	if (!user_dev->core)
+		return;
+
+	/* Are there any other user devices left referencing the core device? */
+	for (dev = dev_list; dev; dev = dev->next) {
+		if (dev == user_dev)
+			continue;
+
+		if (dev->core == user_dev->core)
+			break;
+	}
+
+	if (!dev)
+		amdgpu_device_free(user_dev->core);
+}
+
 static int amdgpu_device_init(amdgpu_device_handle user_dev)
 {
 	struct amdgpu_device *dev_iter;
@@ -115,7 +132,6 @@ static int amdgpu_device_init(amdgpu_device_handle user_dev)
 			break;
 
 	if (dev_iter) {
-		dev_iter->core->refcount++;
 		user_dev->core = dev_iter->core;
 		return 0;
 	}
@@ -126,7 +142,6 @@ static int amdgpu_device_init(amdgpu_device_handle user_dev)
 		return -ENOMEM;
 	}
 
-	dev->refcount = 1;
 	pthread_mutex_init(&dev->bo_table_mutex, NULL);
 
 	dev->fd = user_dev->user_fd;
@@ -251,8 +266,7 @@ out:
 cleanup:
 	if (!user_dev->core || user_dev->user_fd != user_dev->core->fd)
 		close(user_dev->user_fd);
-	if (user_dev->core)
-		amdgpu_device_free(user_dev->core);
+	amdgpu_device_unreference(user_dev);
 	free(user_dev);
 	pthread_mutex_unlock(&dev_mutex);
 	return r;
@@ -274,7 +288,7 @@ drm_public int amdgpu_device_deinitialize(amdgpu_device_handle user_dev)
 		if (user_dev->user_fd != dev->fd)
 			close(user_dev->user_fd);
 
-		amdgpu_device_free(dev);
+		amdgpu_device_unreference(user_dev);
 
 		free(user_dev);
 	}
diff --git a/amdgpu/amdgpu_internal.h b/amdgpu/amdgpu_internal.h
index 70566f98..7110e30c 100644
--- a/amdgpu/amdgpu_internal.h
+++ b/amdgpu/amdgpu_internal.h
@@ -65,7 +65,6 @@ struct amdgpu_va {
 };
 
 struct amdgpu_core_device {
-	int refcount;
 	int fd;
 	unsigned major_version;
 	unsigned minor_version;
@@ -97,7 +96,6 @@ struct amdgpu_device {
 };
 
 struct amdgpu_core_bo {
-	int refcount;
 	amdgpu_bo_handle user_bos;
 
 	uint64_t alloc_size;
-- 
2.20.1