text: /*
   * Copyright 2014 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 <bskeggs@redhat.com>
   */
  
  #include "nouveau_drm.h"
  #include "nouveau_usif.h"
  
  #include <nvif/notify.h>
  #include <nvif/unpack.h>
  #include <nvif/client.h>
  #include <nvif/event.h>
  #include <nvif/ioctl.h>
  
  struct usif_notify_p {
  	struct drm_pending_event base;
  	struct {
  		struct drm_event base;
  		u8 data[];
  	} e;
  };
  
  struct usif_notify {
  	struct list_head head;
  	atomic_t enabled;
  	u32 handle;
  	u16 reply;
  	u8  route;
  	u64 token;
  	struct usif_notify_p *p;
  };
  
  static inline struct usif_notify *
  usif_notify_find(struct drm_file *filp, u32 handle)
  {
  	struct nouveau_cli *cli = nouveau_cli(filp);
  	struct usif_notify *ntfy;
  	list_for_each_entry(ntfy, &cli->notifys, head) {
  		if (ntfy->handle == handle)
  			return ntfy;
  	}
  	return NULL;
  }
  
  static inline void
  usif_notify_dtor(struct usif_notify *ntfy)
  {
  	list_del(&ntfy->head);
  	kfree(ntfy);
  }
  
  int
  usif_notify(const void *header, u32 length, const void *data, u32 size)
  {
  	struct usif_notify *ntfy = NULL;
  	const union {
  		struct nvif_notify_rep_v0 v0;
  	} *rep = header;
  	struct drm_device *dev;
  	struct drm_file *filp;
  	unsigned long flags;
  
  	if (length == sizeof(rep->v0) && rep->v0.version == 0) {
  		if (WARN_ON(!(ntfy = (void *)(unsigned long)rep->v0.token)))
  			return NVIF_NOTIFY_DROP;
  		BUG_ON(rep->v0.route != NVDRM_NOTIFY_USIF);
  	} else
  	if (WARN_ON(1))
  		return NVIF_NOTIFY_DROP;
  
  	if (WARN_ON(!ntfy->p || ntfy->reply != (length + size)))
  		return NVIF_NOTIFY_DROP;
  	filp = ntfy->p->base.file_priv;
  	dev = filp->minor->dev;
  
  	memcpy(&ntfy->p->e.data[0], header, length);
  	memcpy(&ntfy->p->e.data[length], data, size);
  	switch (rep->v0.version) {
  	case 0: {
  		struct nvif_notify_rep_v0 *rep = (void *)ntfy->p->e.data;
  		rep->route = ntfy->route;
  		rep->token = ntfy->token;
  	}
  		break;
  	default:
  		BUG_ON(1);
  		break;
  	}
  
  	spin_lock_irqsave(&dev->event_lock, flags);
  	if (!WARN_ON(filp->event_space < ntfy->p->e.base.length)) {
  		list_add_tail(&ntfy->p->base.link, &filp->event_list);
  		filp->event_space -= ntfy->p->e.base.length;
  	}
  	wake_up_interruptible(&filp->event_wait);
  	spin_unlock_irqrestore(&dev->event_lock, flags);
  	atomic_set(&ntfy->enabled, 0);
  	return NVIF_NOTIFY_DROP;
  }
  
  static int
  usif_notify_new(struct drm_file *f, void *data, u32 size, void *argv, u32 argc)
  {
  	struct nouveau_cli *cli = nouveau_cli(f);
  	struct nvif_client *client = &cli->base;
  	union {
  		struct nvif_ioctl_ntfy_new_v0 v0;
  	} *args = data;
  	union {
  		struct nvif_notify_req_v0 v0;
  	} *req;
  	struct usif_notify *ntfy;
  	int ret;
  
  	if (nvif_unpack(args->v0, 0, 0, true)) {
  		if (usif_notify_find(f, args->v0.index))
  			return -EEXIST;
  	} else
  		return ret;
  	req = data;
  
  	if (!(ntfy = kmalloc(sizeof(*ntfy), GFP_KERNEL)))
  		return -ENOMEM;
  	atomic_set(&ntfy->enabled, 0);
  
  	if (nvif_unpack(req->v0, 0, 0, true)) {
  		ntfy->reply = sizeof(struct nvif_notify_rep_v0) + req->v0.reply;
  		ntfy->route = req->v0.route;
  		ntfy->token = req->v0.token;
  		req->v0.route = NVDRM_NOTIFY_USIF;
  		req->v0.token = (unsigned long)(void *)ntfy;
  		ret = nvif_client_ioctl(client, argv, argc);
  		req->v0.token = ntfy->token;
  		req->v0.route = ntfy->route;
  		ntfy->handle = args->v0.index;
  	}
  
  	if (ret == 0)
  		list_add(&ntfy->head, &cli->notifys);
  	if (ret)
  		kfree(ntfy);
  	return ret;
  }
  
  static int
  usif_notify_del(struct drm_file *f, void *data, u32 size, void *argv, u32 argc)
  {
  	struct nouveau_cli *cli = nouveau_cli(f);
  	struct nvif_client *client = &cli->base;
  	union {
  		struct nvif_ioctl_ntfy_del_v0 v0;
  	} *args = data;
  	struct usif_notify *ntfy;
  	int ret;
  
  	if (nvif_unpack(args->v0, 0, 0, true)) {
  		if (!(ntfy = usif_notify_find(f, args->v0.index)))
  			return -ENOENT;
  	} else
  		return ret;
  
  	ret = nvif_client_ioctl(client, argv, argc);
  	if (ret == 0)
  		usif_notify_dtor(ntfy);
  	return ret;
  }
  
  static int
  usif_notify_get(struct drm_file *f, void *data, u32 size, void *argv, u32 argc)
  {
  	struct nouveau_cli *cli = nouveau_cli(f);
  	struct nvif_client *client = &cli->base;
  	union {
  		struct nvif_ioctl_ntfy_del_v0 v0;
  	} *args = data;
  	struct usif_notify *ntfy;
  	int ret;
  
  	if (nvif_unpack(args->v0, 0, 0, true)) {
  		if (!(ntfy = usif_notify_find(f, args->v0.index)))
  			return -ENOENT;
  	} else
  		return ret;
  
  	if (atomic_xchg(&ntfy->enabled, 1))
  		return 0;
  
  	ntfy->p = kmalloc(sizeof(*ntfy->p) + ntfy->reply, GFP_KERNEL);
  	if (ret = -ENOMEM, !ntfy->p)
  		goto done;
  	ntfy->p->base.event = &ntfy->p->e.base;
  	ntfy->p->base.file_priv = f;
  	ntfy->p->base.pid = current->pid;
  	ntfy->p->base.destroy =(void(*)(struct drm_pending_event *))kfree;
  	ntfy->p->e.base.type = DRM_NOUVEAU_EVENT_NVIF;
  	ntfy->p->e.base.length = sizeof(ntfy->p->e.base) + ntfy->reply;
  
  	ret = nvif_client_ioctl(client, argv, argc);
  done:
  	if (ret) {
  		atomic_set(&ntfy->enabled, 0);
  		kfree(ntfy->p);
  	}
  	return ret;
  }
  
  static int
  usif_notify_put(struct drm_file *f, void *data, u32 size, void *argv, u32 argc)
  {
  	struct nouveau_cli *cli = nouveau_cli(f);
  	struct nvif_client *client = &cli->base;
  	union {
  		struct nvif_ioctl_ntfy_put_v0 v0;
  	} *args = data;
  	struct usif_notify *ntfy;
  	int ret;
  
  	if (nvif_unpack(args->v0, 0, 0, true)) {
  		if (!(ntfy = usif_notify_find(f, args->v0.index)))
  			return -ENOENT;
  	} else
  		return ret;
  
  	ret = nvif_client_ioctl(client, argv, argc);
  	if (ret == 0 && atomic_xchg(&ntfy->enabled, 0))
  		kfree(ntfy->p);
  	return ret;
  }
  
  struct usif_object {
  	struct list_head head;
  	struct list_head ntfy;
  	u8  route;
  	u64 token;
  };
  
  static void
  usif_object_dtor(struct usif_object *object)
  {
  	list_del(&object->head);
  	kfree(object);
  }
  
  static int
  usif_object_new(struct drm_file *f, void *data, u32 size, void *argv, u32 argc)
  {
  	struct nouveau_cli *cli = nouveau_cli(f);
  	struct nvif_client *client = &cli->base;
  	union {
  		struct nvif_ioctl_new_v0 v0;
  	} *args = data;
  	struct usif_object *object;
  	int ret;
  
  	if (!(object = kmalloc(sizeof(*object), GFP_KERNEL)))
  		return -ENOMEM;
  	list_add(&object->head, &cli->objects);
  
  	if (nvif_unpack(args->v0, 0, 0, true)) {
  		object->route = args->v0.route;
  		object->token = args->v0.token;
  		args->v0.route = NVDRM_OBJECT_USIF;
  		args->v0.token = (unsigned long)(void *)object;
  		ret = nvif_client_ioctl(client, argv, argc);
  		args->v0.token = object->token;
  		args->v0.route = object->route;
  	}
  
  	if (ret)
  		usif_object_dtor(object);
  	return ret;
  }
  
  int
  usif_ioctl(struct drm_file *filp, void __user *user, u32 argc)
  {
  	struct nouveau_cli *cli = nouveau_cli(filp);
  	struct nvif_client *client = &cli->base;
  	void *data = kmalloc(argc, GFP_KERNEL);
  	u32   size = argc;
  	union {
  		struct nvif_ioctl_v0 v0;
  	} *argv = data;
  	struct usif_object *object;
  	u8 owner;
  	int ret;
  
  	if (ret = -ENOMEM, !argv)
  		goto done;
  	if (ret = -EFAULT, copy_from_user(argv, user, size))
  		goto done;
  
  	if (nvif_unpack(argv->v0, 0, 0, true)) {
  		/* block access to objects not created via this interface */
  		owner = argv->v0.owner;
  		argv->v0.owner = NVDRM_OBJECT_USIF;
  	} else
  		goto done;
  
  	mutex_lock(&cli->mutex);
  	switch (argv->v0.type) {
  	case NVIF_IOCTL_V0_NEW:
  		/* ... except if we're creating children */
  		argv->v0.owner = NVIF_IOCTL_V0_OWNER_ANY;
  		ret = usif_object_new(filp, data, size, argv, argc);
  		break;
  	case NVIF_IOCTL_V0_NTFY_NEW:
  		ret = usif_notify_new(filp, data, size, argv, argc);
  		break;
  	case NVIF_IOCTL_V0_NTFY_DEL:
  		ret = usif_notify_del(filp, data, size, argv, argc);
  		break;
  	case NVIF_IOCTL_V0_NTFY_GET:
  		ret = usif_notify_get(filp, data, size, argv, argc);
  		break;
  	case NVIF_IOCTL_V0_NTFY_PUT:
  		ret = usif_notify_put(filp, data, size, argv, argc);
  		break;
  	default:
  		ret = nvif_client_ioctl(client, argv, argc);
  		break;
  	}
  	if (argv->v0.route == NVDRM_OBJECT_USIF) {
  		object = (void *)(unsigned long)argv->v0.token;
  		argv->v0.route = object->route;
  		argv->v0.token = object->token;
  		if (ret == 0 && argv->v0.type == NVIF_IOCTL_V0_DEL) {
  			list_del(&object->head);
  			kfree(object);
  		}
  	} else {
  		argv->v0.route = NVIF_IOCTL_V0_ROUTE_HIDDEN;
  		argv->v0.token = 0;
  	}
  	argv->v0.owner = owner;
  	mutex_unlock(&cli->mutex);
  
  	if (copy_to_user(user, argv, argc))
  		ret = -EFAULT;
  done:
  	kfree(argv);
  	return ret;
  }
  
  void
  usif_client_fini(struct nouveau_cli *cli)
  {
  	struct usif_object *object, *otemp;
  	struct usif_notify *notify, *ntemp;
  
  	list_for_each_entry_safe(notify, ntemp, &cli->notifys, head) {
  		usif_notify_dtor(notify);
  	}
  
  	list_for_each_entry_safe(object, otemp, &cli->objects, head) {
  		usif_object_dtor(object);
  	}
  }
  
  void
  usif_client_init(struct nouveau_cli *cli)
  {
  	INIT_LIST_HEAD(&cli->objects);
  	INIT_LIST_HEAD(&cli->notifys);
  }
  