drm/nouveau: make client's notify array dynamic

The number of notify objects per channel varies by several factors, and
now with the error notifier it depends also linearly on the number of
channels. Instead of the fixed 32, reallocate the notify object array to
twice the previous space when adding a new element if it's full. The
first allocation size is 16.

Note that this doesn't grow boundless even though the array never
shrinks and is only completely deleted at dtor(). Dead notify objects
are replaced with NULL and those slots are reused when new ones are
allocated, as before.

Change-Id: I970e7e0f334e3ba8626ab07b8e6d3569339f39bc
Signed-off-by: Konsta Holtta <kholtta@nvidia.com>
Reviewed-on: https://chromium-review.googlesource.com/304520
Reviewed-by: Vince Hsu <vince.h@nvidia.com>
Reviewed-by: Andrew Bresticker <abrestic@chromium.org>

drivers/gpu/drm/nouveau/include/nvkm/core/client.h

@@ -13,7 +13,8 @@ struct nvkm_client {
 	void *data;
 
 	int (*ntfy)(const void *, u32, const void *, u32);
-	struct nvkm_client_notify *notify[32];
+	struct nvkm_client_notify **notify;
+	int notify_size;
 };
 
 static inline struct nvkm_client *

drivers/gpu/drm/nouveau/nvkm/core/client.c

@@ -52,7 +52,7 @@ nvkm_client_notify(struct nvkm_notify *n)
 int
 nvkm_client_notify_put(struct nvkm_client *client, int index)
 {
-	if (index < ARRAY_SIZE(client->notify)) {
+	if (index < client->notify_size) {
 		if (client->notify[index]) {
 			nvkm_notify_put(&client->notify[index]->n);
 			return 0;
@@ -64,7 +64,7 @@ nvkm_client_notify_put(struct nvkm_client *client, int index)
 int
 nvkm_client_notify_get(struct nvkm_client *client, int index)
 {
-	if (index < ARRAY_SIZE(client->notify)) {
+	if (index < client->notify_size) {
 		if (client->notify[index]) {
 			nvkm_notify_get(&client->notify[index]->n);
 			return 0;
@@ -76,7 +76,7 @@ nvkm_client_notify_get(struct nvkm_client *client, int index)
 int
 nvkm_client_notify_del(struct nvkm_client *client, int index)
 {
-	if (index < ARRAY_SIZE(client->notify)) {
+	if (index < client->notify_size) {
 		if (client->notify[index]) {
 			nvkm_notify_fini(&client->notify[index]->n);
 			kfree(client->notify[index]);
@@ -99,13 +99,25 @@ nvkm_client_notify_new(struct nvkm_object *object,
 	u8  index, reply;
 	int ret;
 
-	for (index = 0; index < ARRAY_SIZE(client->notify); index++) {
+	for (index = 0; index < client->notify_size; index++) {
 		if (!client->notify[index])
 			break;
 	}
 
-	if (index == ARRAY_SIZE(client->notify))
-		return -ENOSPC;
+	if (index == client->notify_size) {
+		int old_size = client->notify_size;
+		int new_size = old_size ? 2 * old_size : 16;
+		struct nvkm_client_notify **new_notify = kcalloc(new_size,
+				sizeof(*new_notify), GFP_KERNEL);
+
+		if (!new_notify)
+			return -ENOMEM;
+		memcpy(new_notify, client->notify,
+				old_size * sizeof(*new_notify));
+		kfree(client->notify);
+		client->notify = new_notify;
+		client->notify_size = new_size;
+	}
 
 	notify = kzalloc(sizeof(*notify), GFP_KERNEL);
 	if (!notify)
@@ -181,8 +193,11 @@ nvkm_client_dtor(struct nvkm_object *object)
 {
 	struct nvkm_client *client = (void *)object;
 	int i;
-	for (i = 0; i < ARRAY_SIZE(client->notify); i++)
+	for (i = 0; i < client->notify_size; i++)
 		nvkm_client_notify_del(client, i);
+	kfree(client->notify);
+	client->notify = NULL;
+	client->notify_size = 0;
 	nvkm_object_ref(NULL, &client->device);
 	nvkm_handle_destroy(client->root);
 	nvkm_namedb_destroy(&client->namedb);
@@ -227,6 +242,8 @@ nvkm_client_create_(const char *name, u64 devname, const char *cfg,
 	nvkm_object_ref(device, &client->device);
 	snprintf(client->name, sizeof(client->name), "%s", name);
 	client->debug = nvkm_dbgopt(dbg, "CLIENT");
+	client->notify = NULL;
+	client->notify_size = 0;
 	return 0;
 }
 
@@ -247,7 +264,7 @@ nvkm_client_fini(struct nvkm_client *client, bool suspend)
 	int ret, i;
 	nv_debug(client, "%s running\n", name[suspend]);
 	nv_debug(client, "%s notify\n", name[suspend]);
-	for (i = 0; i < ARRAY_SIZE(client->notify); i++)
+	for (i = 0; i < client->notify_size; i++)
 		nvkm_client_notify_put(client, i);
 	nv_debug(client, "%s object\n", name[suspend]);
 	ret = nvkm_handle_fini(client->root, suspend);