alistair23-linux/drivers/gpu/drm/drm_ioctl.c

/**
 * \file drm_ioctl.c
 * IOCTL processing for DRM
 *
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 */

/*
 * Created: Fri Jan  8 09:01:26 1999 by faith@valinux.com
 *
 * Copyright 1999 Precision Insight, Inc., Cedar Park, Texas.
 * Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
 * All Rights Reserved.
 *
 * 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 (including the next
 * paragraph) 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
 * VA LINUX SYSTEMS AND/OR ITS SUPPLIERS 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.
 */

#include <drm/drmP.h>
#include <drm/drm_core.h>

#include <linux/pci.h>
#include <linux/export.h>
#ifdef CONFIG_X86
#include <asm/mtrr.h>
#endif

/**
 * Get the bus id.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_unique structure.
 * \return zero on success or a negative number on failure.
 *
 * Copies the bus id from drm_device::unique into user space.
 */
int drm_getunique(struct drm_device *dev, void *data,
		  struct drm_file *file_priv)
{
	struct drm_unique *u = data;
	struct drm_master *master = file_priv->master;

	if (u->unique_len >= master->unique_len) {
		if (copy_to_user(u->unique, master->unique, master->unique_len))
			return -EFAULT;
	}
	u->unique_len = master->unique_len;

	return 0;
}

static void
drm_unset_busid(struct drm_device *dev,
		struct drm_master *master)
{
	kfree(dev->devname);
	dev->devname = NULL;

	kfree(master->unique);
	master->unique = NULL;
	master->unique_len = 0;
	master->unique_size = 0;
}

/**
 * Set the bus id.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_unique structure.
 * \return zero on success or a negative number on failure.
 *
 * Copies the bus id from userspace into drm_device::unique, and verifies that
 * it matches the device this DRM is attached to (EINVAL otherwise).  Deprecated
 * in interface version 1.1 and will return EBUSY when setversion has requested
 * version 1.1 or greater.
 */
int drm_setunique(struct drm_device *dev, void *data,
		  struct drm_file *file_priv)
{
	struct drm_unique *u = data;
	struct drm_master *master = file_priv->master;
	int ret;

	if (master->unique_len || master->unique)
		return -EBUSY;

	if (!u->unique_len || u->unique_len > 1024)
		return -EINVAL;

	if (!dev->driver->bus->set_unique)
		return -EINVAL;

	ret = dev->driver->bus->set_unique(dev, master, u);
	if (ret)
		goto err;

	return 0;

err:
	drm_unset_busid(dev, master);
	return ret;
}

static int drm_set_busid(struct drm_device *dev, struct drm_file *file_priv)
{
	struct drm_master *master = file_priv->master;
	int ret;

	if (master->unique != NULL)
		drm_unset_busid(dev, master);

	ret = dev->driver->bus->set_busid(dev, master);
	if (ret)
		goto err;
	return 0;
err:
	drm_unset_busid(dev, master);
	return ret;
}

/**
 * Get a mapping information.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_map structure.
 *
 * \return zero on success or a negative number on failure.
 *
 * Searches for the mapping with the specified offset and copies its information
 * into userspace
 */
int drm_getmap(struct drm_device *dev, void *data,
	       struct drm_file *file_priv)
{
	struct drm_map *map = data;
	struct drm_map_list *r_list = NULL;
	struct list_head *list;
	int idx;
	int i;

	idx = map->offset;
	if (idx < 0)
		return -EINVAL;

	i = 0;
	mutex_lock(&dev->struct_mutex);
	list_for_each(list, &dev->maplist) {
		if (i == idx) {
			r_list = list_entry(list, struct drm_map_list, head);
			break;
		}
		i++;
	}
	if (!r_list || !r_list->map) {
		mutex_unlock(&dev->struct_mutex);
		return -EINVAL;
	}

	map->offset = r_list->map->offset;
	map->size = r_list->map->size;
	map->type = r_list->map->type;
	map->flags = r_list->map->flags;
	map->handle = (void *)(unsigned long) r_list->user_token;

#ifdef CONFIG_X86
	/*
	 * There appears to be exactly one user of the mtrr index: dritest.
	 * It's easy enough to keep it working on non-PAT systems.
	 */
	map->mtrr = phys_wc_to_mtrr_index(r_list->map->mtrr);
#else
	map->mtrr = -1;
#endif

	mutex_unlock(&dev->struct_mutex);

	return 0;
}

/**
 * Get client information.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_client structure.
 *
 * \return zero on success or a negative number on failure.
 *
 * Searches for the client with the specified index and copies its information
 * into userspace
 */
int drm_getclient(struct drm_device *dev, void *data,
		  struct drm_file *file_priv)
{
	struct drm_client *client = data;

	/*
	 * Hollowed-out getclient ioctl to keep some dead old drm tests/tools
	 * not breaking completely. Userspace tools stop enumerating one they
	 * get -EINVAL, hence this is the return value we need to hand back for
	 * no clients tracked.
	 *
	 * Unfortunately some clients (*cough* libva *cough*) use this in a fun
	 * attempt to figure out whether they're authenticated or not. Since
	 * that's the only thing they care about, give it to the directly
	 * instead of walking one giant list.
	 */
	if (client->idx == 0) {
		client->auth = file_priv->authenticated;
		client->pid = pid_vnr(file_priv->pid);
		client->uid = from_kuid_munged(current_user_ns(),
					       file_priv->uid);
		client->magic = 0;
		client->iocs = 0;

		return 0;
	} else {
		return -EINVAL;
	}
}

/**
 * Get statistics information.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_stats structure.
 *
 * \return zero on success or a negative number on failure.
 */
int drm_getstats(struct drm_device *dev, void *data,
		 struct drm_file *file_priv)
{
	struct drm_stats *stats = data;

	/* Clear stats to prevent userspace from eating its stack garbage. */
	memset(stats, 0, sizeof(*stats));

	return 0;
}

/**
 * Get device/driver capabilities
 */
int drm_getcap(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	struct drm_get_cap *req = data;

	req->value = 0;
	switch (req->capability) {
	case DRM_CAP_DUMB_BUFFER:
		if (dev->driver->dumb_create)
			req->value = 1;
		break;
	case DRM_CAP_VBLANK_HIGH_CRTC:
		req->value = 1;
		break;
	case DRM_CAP_DUMB_PREFERRED_DEPTH:
		req->value = dev->mode_config.preferred_depth;
		break;
	case DRM_CAP_DUMB_PREFER_SHADOW:
		req->value = dev->mode_config.prefer_shadow;
		break;
	case DRM_CAP_PRIME:
		req->value |= dev->driver->prime_fd_to_handle ? DRM_PRIME_CAP_IMPORT : 0;
		req->value |= dev->driver->prime_handle_to_fd ? DRM_PRIME_CAP_EXPORT : 0;
		break;
	case DRM_CAP_TIMESTAMP_MONOTONIC:
		req->value = drm_timestamp_monotonic;
		break;
	default:
		return -EINVAL;
	}
	return 0;
}

/**
 * Setversion ioctl.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument, pointing to a drm_lock structure.
 * \return zero on success or negative number on failure.
 *
 * Sets the requested interface version
 */
int drm_setversion(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	struct drm_set_version *sv = data;
	int if_version, retcode = 0;

	if (sv->drm_di_major != -1) {
		if (sv->drm_di_major != DRM_IF_MAJOR ||
		    sv->drm_di_minor < 0 || sv->drm_di_minor > DRM_IF_MINOR) {
			retcode = -EINVAL;
			goto done;
		}
		if_version = DRM_IF_VERSION(sv->drm_di_major,
					    sv->drm_di_minor);
		dev->if_version = max(if_version, dev->if_version);
		if (sv->drm_di_minor >= 1) {
			/*
			 * Version 1.1 includes tying of DRM to specific device
			 * Version 1.4 has proper PCI domain support
			 */
			retcode = drm_set_busid(dev, file_priv);
			if (retcode)
				goto done;
		}
	}

	if (sv->drm_dd_major != -1) {
		if (sv->drm_dd_major != dev->driver->major ||
		    sv->drm_dd_minor < 0 || sv->drm_dd_minor >
		    dev->driver->minor) {
			retcode = -EINVAL;
			goto done;
		}
	}

done:
	sv->drm_di_major = DRM_IF_MAJOR;
	sv->drm_di_minor = DRM_IF_MINOR;
	sv->drm_dd_major = dev->driver->major;
	sv->drm_dd_minor = dev->driver->minor;

	return retcode;
}

/** No-op ioctl. */
int drm_noop(struct drm_device *dev, void *data,
	     struct drm_file *file_priv)
{
	DRM_DEBUG("\n");
	return 0;
}
EXPORT_SYMBOL(drm_noop);