[RFC 23/26] plugins/amdgpu: Consolidate shared memory handling

Shortly we will need to share more data between the processes being
restored so lets move all of it under the same top level object to make it
easier to add new struct members.

Signed-off-by: Tvrtko Ursulin <[email protected]>
---
 plugins/amdgpu/amdgpu_plugin.c | 85 ++++++++++++++++++++--------------
 1 file changed, 49 insertions(+), 36 deletions(-)

diff --git a/plugins/amdgpu/amdgpu_plugin.c b/plugins/amdgpu/amdgpu_plugin.c
index 664536850c42..f4bda11b3de5 100644
--- a/plugins/amdgpu/amdgpu_plugin.c
+++ b/plugins/amdgpu/amdgpu_plugin.c
@@ -71,13 +71,12 @@ struct handle_id {
 	int handle;
 	int fdstore_id;
 };
-struct shared_handle_ids {
-	int num_handles;
-	struct handle_id *handles;
-};
-struct shared_handle_ids *shared_memory = NULL;
 
-static mutex_t *shared_memory_mutex;
+static struct shared_memory {
+	mutex_t			mutex;
+	int 			num_handles;
+	struct handle_id	*handles;
+} *shared_memory;
 
 /*
  * In the case of a single process (common case), this optimization can effectively
@@ -1100,38 +1099,47 @@ CR_PLUGIN_REGISTER_HOOK(CR_PLUGIN_HOOK__DUMP_DEVICES_LATE, amdgpu_unpause_proces
 
 int store_dmabuf_fd(int handle, int fd)
 {
+	int ret = -1;
 	int id;
 
+	if (!shared_memory)
+		return -1;
+
 	id = fdstore_add(fd);
-	mutex_lock(shared_memory_mutex);
+	mutex_lock(&shared_memory->mutex);
 	for (int i = 0; i < shared_memory->num_handles; i++) {
 		if (shared_memory->handles[i].handle == handle) {
-			mutex_unlock(shared_memory_mutex);
-			return 0;
-		}
-		if (shared_memory->handles[i].handle == -1) {
+			ret = 0;
+			break;
+		} else if (shared_memory->handles[i].handle == -1) {
 			shared_memory->handles[i].handle = handle;
 			shared_memory->handles[i].fdstore_id = id;
-			mutex_unlock(shared_memory_mutex);
-			return 0;
+			ret = 0;
+			break;
 		}
 	}
-	mutex_unlock(shared_memory_mutex);
+	mutex_unlock(&shared_memory->mutex);
 
-	return -1;
+	return ret;
 }
 
 int amdgpu_id_for_handle(int handle)
 {
-	mutex_lock(shared_memory_mutex);
+	int ret = -1;
+
+	if (!shared_memory)
+		return -1;
+
+	mutex_lock(&shared_memory->mutex);
 	for (int i = 0; i < shared_memory->num_handles; i++) {
 		if (shared_memory->handles[i].handle == handle) {
-			mutex_unlock(shared_memory_mutex);
-			return shared_memory->handles[i].fdstore_id;
+			ret = shared_memory->handles[i].fdstore_id;
+			break;
 		}
 	}
-	mutex_unlock(shared_memory_mutex);
-	return -1;
+	mutex_unlock(&shared_memory->mutex);
+
+	return ret;
 }
 
 static int load_img(char *filename, unsigned char **out_buf, size_t *out_len)
@@ -1212,27 +1220,32 @@ int amdgpu_restore_init(void)
 	}
 	closedir(d);
 
-	if (num_handles > 0) {
-		const int protection = PROT_READ | PROT_WRITE;
-		const int visibility = MAP_SHARED | MAP_ANONYMOUS;
+	if (!num_handles)
+		return 0;
 
-		shared_memory = mmap(NULL, sizeof(shared_memory), protection, visibility, -1, 0);
-		shared_memory->num_handles = num_handles;
-		shared_memory->handles = mmap(NULL, sizeof(struct handle_id) * num_handles, protection, visibility, -1, 0);
+	shared_memory = shmalloc(sizeof(*shared_memory));
+	if (!shared_memory) {
+		pr_err("Can't create amdgpu shared memory\n");
+		return -1;
+	}
 
-		for (int i = 0; i < num_handles; i++) {
-			shared_memory->handles[i].handle = -1;
-			shared_memory->handles[i].fdstore_id = -1;
-		}
+	shared_memory->handles = shmalloc(num_handles *
+					  sizeof(*shared_memory->handles));
+	if (!shared_memory->handles) {
+		shfree_last(shared_memory);
+		pr_err("Can't create amdgpu shared memory handles\n");
+		return -1;
+	}
 
-		shared_memory_mutex = shmalloc(sizeof(*shared_memory_mutex));
-		if (!shared_memory_mutex) {
-			pr_err("Can't create amdgpu mutex\n");
-			return -1;
-		}
-		mutex_init(shared_memory_mutex);
+	for (int i = 0; i < num_handles; i++) {
+		shared_memory->handles[i].handle = -1;
+		shared_memory->handles[i].fdstore_id = -1;
 	}
 
+	mutex_init(&shared_memory->mutex);
+
+	shared_memory->num_handles = num_handles;
+
 	return 0;
 }
 CR_PLUGIN_REGISTER_HOOK(CR_PLUGIN_HOOK__RESTORE_INIT, amdgpu_restore_init)
-- 
2.52.0