drm/nouveau/core/client: allow creation of subclients

We want a supervisor client of NVKM (such as the DRM) to be able to
allow sharing of resources (such as memory objects) between clients.

To allow this, the supervisor creates all its clients as children of
itself, and will use an upcoming ioctl to permit sharing.

Currently it's not possible for indirect clients to use subclients.
Supporting this will require an additional field in the main ioctl.
This isn't important currently, but will need to be fixed for virt.

Signed-off-by: Ben Skeggs <[e-mail]>

drivers/gpu/drm/nouveau/include/nvif/client.h

···
 	bool super;
 };
 
-int  nvif_client_init(const char *drv, const char *name, u64 device,
-		      const char *cfg, const char *dbg,
+int  nvif_client_init(struct nvif_client *parent, const char *name, u64 device,
 		      struct nvif_client *);
 void nvif_client_fini(struct nvif_client *);
 int  nvif_client_ioctl(struct nvif_client *, void *, u32);

drivers/gpu/drm/nouveau/include/nvif/driver.h

···
 #ifndef __NVIF_DRIVER_H__
 #define __NVIF_DRIVER_H__
+#include <nvif/os.h>
+struct nvif_client;
 
 struct nvif_driver {
 	const char *name;
···
 	bool keep;
 };
 
+int nvif_driver_init(const char *drv, const char *cfg, const char *dbg,
+		     const char *name, u64 device, struct nvif_client *);
+
 extern const struct nvif_driver nvif_driver_nvkm;
 extern const struct nvif_driver nvif_driver_drm;
 extern const struct nvif_driver nvif_driver_lib;
 extern const struct nvif_driver nvif_driver_null;
-
 #endif

drivers/gpu/drm/nouveau/include/nvif/if0000.h

···
 #ifndef __NVIF_IF0000_H__
 #define __NVIF_IF0000_H__
 
+struct nvif_client_v0 {
+	__u8  version;
+	__u8  pad01[7];
+	__u64 device;
+	char  name[32];
+};
+
 #define NVIF_CLIENT_V0_DEVLIST                                             0x00
 
 struct nvif_client_devlist_v0 {

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

···
 		     const char *dbg,
 		     int (*)(const void *, u32, const void *, u32),
 		     struct nvkm_client **);
+struct nvkm_client *nvkm_client_search(struct nvkm_client *, u64 handle);
 
 int nvkm_client_notify_new(struct nvkm_object *, struct nvkm_event *,
 			   void *data, u32 size);

drivers/gpu/drm/nouveau/nouveau_drm.c

···
 #include <core/pci.h>
 #include <core/tegra.h>
 
+#include <nvif/driver.h>
+
 #include <nvif/class.h>
 #include <nvif/cl0002.h>
 #include <nvif/cla06f.h>
···
 		snprintf(cli->name, sizeof(cli->name), "%s", sname);
 		cli->dev = dev;
 
-		ret = nvif_client_init(NULL, cli->name, nouveau_name(dev),
-				       nouveau_config, nouveau_debug,
+		ret = nvif_driver_init(NULL, nouveau_config, nouveau_debug,
+				       cli->name, nouveau_name(dev),
 				       &cli->base);
 		if (ret == 0) {
 			mutex_init(&cli->mutex);

drivers/gpu/drm/nouveau/nvif/Kbuild

···
 nvif-y := nvif/object.o
 nvif-y += nvif/client.o
 nvif-y += nvif/device.o
+nvif-y += nvif/driver.o
 nvif-y += nvif/notify.o

drivers/gpu/drm/nouveau/nvif/client.c

···
 #include <nvif/driver.h>
 #include <nvif/ioctl.h>
 
+#include <nvif/class.h>
+#include <nvif/if0000.h>
+
 int
 nvif_client_ioctl(struct nvif_client *client, void *data, u32 size)
 {
···
 	}
 }
 
-static const struct nvif_driver *
-nvif_drivers[] = {
-#ifdef __KERNEL__
-	&nvif_driver_nvkm,
-#else
-	&nvif_driver_drm,
-	&nvif_driver_lib,
-	&nvif_driver_null,
-#endif
-	NULL
-};
-
 int
-nvif_client_init(const char *driver, const char *name, u64 device,
-		 const char *cfg, const char *dbg, struct nvif_client *client)
+nvif_client_init(struct nvif_client *parent, const char *name, u64 device,
+		 struct nvif_client *client)
 {
+	struct nvif_client_v0 args = { .device = device };
 	struct {
 		struct nvif_ioctl_v0 ioctl;
 		struct nvif_ioctl_nop_v0 nop;
-	} args = {};
-	int ret, i;
+	} nop = {};
+	int ret;
 
-	ret = nvif_object_init(NULL, 0, 0, NULL, 0, &client->object);
+	strncpy(args.name, name, sizeof(args.name));
+	ret = nvif_object_init(parent != client ? &parent->object : NULL,
+			       0, NVIF_CLASS_CLIENT, &args, sizeof(args),
+			       &client->object);
 	if (ret)
 		return ret;
 
···
 	client->object.handle = ~0;
 	client->route = NVIF_IOCTL_V0_ROUTE_NVIF;
 	client->super = true;
-
-	for (i = 0, ret = -EINVAL; (client->driver = nvif_drivers[i]); i++) {
-		if (!driver || !strcmp(client->driver->name, driver)) {
-			ret = client->driver->init(name, device, cfg, dbg,
-						  &client->object.priv);
-			if (!ret || driver)
-				break;
-		}
-	}
+	client->driver = parent->driver;
 
 	if (ret == 0) {
-		ret = nvif_client_ioctl(client, &args, sizeof(args));
-		client->version = args.nop.version;
+		ret = nvif_client_ioctl(client, &nop, sizeof(nop));
+		client->version = nop.nop.version;
 	}
 
 	if (ret)

drivers/gpu/drm/nouveau/nvif/driver.c

···
+/*
+ * Copyright 2016 Red Hat Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the "Software"),
+ * to deal in the Software without restriction, including without limitation
+ * the rights to use, copy, modify, merge, publish, distribute, sublicense,
+ * and/or sell copies of the Software, and to permit persons to whom the
+ * Software is furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
+ * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR
+ * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
+ * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
+ * OTHER DEALINGS IN THE SOFTWARE.
+ *
+ * Authors: Ben Skeggs
+ */
+#include <nvif/driver.h>
+#include <nvif/client.h>
+
+static const struct nvif_driver *
+nvif_driver[] = {
+#ifdef __KERNEL__
+	&nvif_driver_nvkm,
+#else
+	&nvif_driver_drm,
+	&nvif_driver_lib,
+	&nvif_driver_null,
+#endif
+	NULL
+};
+
+int
+nvif_driver_init(const char *drv, const char *cfg, const char *dbg,
+		 const char *name, u64 device, struct nvif_client *client)
+{
+	int ret = -EINVAL, i;
+
+	for (i = 0; (client->driver = nvif_driver[i]); i++) {
+		if (!drv || !strcmp(client->driver->name, drv)) {
+			ret = client->driver->init(name, device, cfg, dbg,
+						   &client->object.priv);
+			if (ret == 0)
+				break;
+			client->driver->fini(client->object.priv);
+		}
+	}
+
+	if (ret == 0)
+		ret = nvif_client_init(client, name, device, client);
+	return ret;
+}

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

···
 #include <nvif/if0000.h>
 #include <nvif/unpack.h>
 
-static const struct nvkm_sclass
+static int
+nvkm_uclient_new(const struct nvkm_oclass *oclass, void *argv, u32 argc,
+		 struct nvkm_object **pobject)
+{
+	union {
+		struct nvif_client_v0 v0;
+	} *args = argv;
+	struct nvkm_client *client;
+	int ret = -ENOSYS;
+
+	if (!(ret = nvif_unpack(ret, &argv, &argc, args->v0, 0, 0, false))){
+		args->v0.name[sizeof(args->v0.name) - 1] = 0;
+		ret = nvkm_client_new(args->v0.name, args->v0.device, NULL,
+				      NULL, oclass->client->ntfy, &client);
+		if (ret)
+			return ret;
+	} else
+		return ret;
+
+	client->object.client = oclass->client;
+	client->object.handle = oclass->handle;
+	client->object.route  = oclass->route;
+	client->object.token  = oclass->token;
+	client->object.object = oclass->object;
+	client->debug = oclass->client->debug;
+	*pobject = &client->object;
+	return 0;
+}
+
+const struct nvkm_sclass
 nvkm_uclient_sclass = {
 	.oclass = NVIF_CLASS_CLIENT,
+	.minver = 0,
+	.maxver = 0,
+	.ctor = nvkm_uclient_new,
 };
 
 struct nvkm_client_notify {
···
 	return ret;
 }
 
+static const struct nvkm_object_func nvkm_client;
+struct nvkm_client *
+nvkm_client_search(struct nvkm_client *client, u64 handle)
+{
+	struct nvkm_object *object;
+
+	object = nvkm_object_search(client, handle, &nvkm_client);
+	if (IS_ERR(object))
+		return (void *)object;
+
+	return nvkm_client(object);
+}
+
 static int
 nvkm_client_mthd_devlist(struct nvkm_client *client, void *data, u32 size)
 {
···
 	const struct nvkm_sclass *sclass;
 
 	switch (index) {
-	case 0: sclass = &nvkm_udevice_sclass; break;
+	case 0: sclass = &nvkm_uclient_sclass; break;
+	case 1: sclass = &nvkm_udevice_sclass; break;
 	default:
 		return -EINVAL;
 	}