[net-next-2.6.git] / drivers / gpu / drm / drm_context.c

/**
 * \file drm_context.c
 * IOCTLs for generic contexts
 *
 * \author Rickard E. (Rik) Faith <faith@valinux.com>
 * \author Gareth Hughes <gareth@valinux.com>
 */

/*
 * Created: Fri Nov 24 18:31:37 2000 by gareth@valinux.com
 *
 * Copyright 1999, 2000 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.
 */

/*
 * ChangeLog:
 *  2001-11-16	Torsten Duwe <duwe@caldera.de>
 *		added context constructor/destructor hooks,
 *		needed by SiS driver's memory management.
 */

#include "drmP.h"

/******************************************************************/
/** \name Context bitmap support */
/*@{*/

/**
 * Free a handle from the context bitmap.
 *
 * \param dev DRM device.
 * \param ctx_handle context handle.
 *
 * Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry
 * in drm_device::ctx_idr, while holding the drm_device::struct_mutex
 * lock.
 */
void drm_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
{
	mutex_lock(&dev->struct_mutex);
	idr_remove(&dev->ctx_idr, ctx_handle);
	mutex_unlock(&dev->struct_mutex);
}

/**
 * Context bitmap allocation.
 *
 * \param dev DRM device.
 * \return (non-negative) context handle on success or a negative number on failure.
 *
 * Allocate a new idr from drm_device::ctx_idr while holding the
 * drm_device::struct_mutex lock.
 */
static int drm_ctxbitmap_next(struct drm_device * dev)
{
	int new_id;
	int ret;

again:
	if (idr_pre_get(&dev->ctx_idr, GFP_KERNEL) == 0) {
		DRM_ERROR("Out of memory expanding drawable idr\n");
		return -ENOMEM;
	}
	mutex_lock(&dev->struct_mutex);
	ret = idr_get_new_above(&dev->ctx_idr, NULL,
				DRM_RESERVED_CONTEXTS, &new_id);
	if (ret == -EAGAIN) {
		mutex_unlock(&dev->struct_mutex);
		goto again;
	}
	mutex_unlock(&dev->struct_mutex);
	return new_id;
}

/**
 * Context bitmap initialization.
 *
 * \param dev DRM device.
 *
 * Initialise the drm_device::ctx_idr
 */
int drm_ctxbitmap_init(struct drm_device * dev)
{
	idr_init(&dev->ctx_idr);
	return 0;
}

/**
 * Context bitmap cleanup.
 *
 * \param dev DRM device.
 *
 * Free all idr members using drm_ctx_sarea_free helper function
 * while holding the drm_device::struct_mutex lock.
 */
void drm_ctxbitmap_cleanup(struct drm_device * dev)
{
	mutex_lock(&dev->struct_mutex);
	idr_remove_all(&dev->ctx_idr);
	mutex_unlock(&dev->struct_mutex);
}

/*@}*/

/******************************************************************/
/** \name Per Context SAREA Support */
/*@{*/

/**
 * Get per-context SAREA.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx_priv_map structure.
 * \return zero on success or a negative number on failure.
 *
 * Gets the map from drm_device::ctx_idr with the handle specified and
 * returns its handle.
 */
int drm_getsareactx(struct drm_device *dev, void *data,
		    struct drm_file *file_priv)
{
	struct drm_ctx_priv_map *request = data;
	struct drm_local_map *map;
	struct drm_map_list *_entry;

	mutex_lock(&dev->struct_mutex);

	map = idr_find(&dev->ctx_idr, request->ctx_id);
	if (!map) {
		mutex_unlock(&dev->struct_mutex);
		return -EINVAL;
	}

	mutex_unlock(&dev->struct_mutex);

	request->handle = NULL;
	list_for_each_entry(_entry, &dev->maplist, head) {
		if (_entry->map == map) {
			request->handle =
			    (void *)(unsigned long)_entry->user_token;
			break;
		}
	}
	if (request->handle == NULL)
		return -EINVAL;

	return 0;
}

/**
 * Set per-context SAREA.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx_priv_map structure.
 * \return zero on success or a negative number on failure.
 *
 * Searches the mapping specified in \p arg and update the entry in
 * drm_device::ctx_idr with it.
 */
int drm_setsareactx(struct drm_device *dev, void *data,
		    struct drm_file *file_priv)
{
	struct drm_ctx_priv_map *request = data;
	struct drm_local_map *map = NULL;
	struct drm_map_list *r_list = NULL;

	mutex_lock(&dev->struct_mutex);
	list_for_each_entry(r_list, &dev->maplist, head) {
		if (r_list->map
		    && r_list->user_token == (unsigned long) request->handle)
			goto found;
	}
      bad:
	mutex_unlock(&dev->struct_mutex);
	return -EINVAL;

      found:
	map = r_list->map;
	if (!map)
		goto bad;

	if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id)))
		goto bad;

	mutex_unlock(&dev->struct_mutex);

	return 0;
}

/*@}*/

/******************************************************************/
/** \name The actual DRM context handling routines */
/*@{*/

/**
 * Switch context.
 *
 * \param dev DRM device.
 * \param old old context handle.
 * \param new new context handle.
 * \return zero on success or a negative number on failure.
 *
 * Attempt to set drm_device::context_flag.
 */
static int drm_context_switch(struct drm_device * dev, int old, int new)
{
	if (test_and_set_bit(0, &dev->context_flag)) {
		DRM_ERROR("Reentering -- FIXME\n");
		return -EBUSY;
	}

	DRM_DEBUG("Context switch from %d to %d\n", old, new);

	if (new == dev->last_context) {
		clear_bit(0, &dev->context_flag);
		return 0;
	}

	return 0;
}

/**
 * Complete context switch.
 *
 * \param dev DRM device.
 * \param new new context handle.
 * \return zero on success or a negative number on failure.
 *
 * Updates drm_device::last_context and drm_device::last_switch. Verifies the
 * hardware lock is held, clears the drm_device::context_flag and wakes up
 * drm_device::context_wait.
 */
static int drm_context_switch_complete(struct drm_device *dev,
				       struct drm_file *file_priv, int new)
{
	dev->last_context = new;	/* PRE/POST: This is the _only_ writer. */
	dev->last_switch = jiffies;

	if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) {
		DRM_ERROR("Lock isn't held after context switch\n");
	}

	/* If a context switch is ever initiated
	   when the kernel holds the lock, release
	   that lock here. */
	clear_bit(0, &dev->context_flag);
	wake_up(&dev->context_wait);

	return 0;
}

/**
 * Reserve contexts.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx_res structure.
 * \return zero on success or a negative number on failure.
 */
int drm_resctx(struct drm_device *dev, void *data,
	       struct drm_file *file_priv)
{
	struct drm_ctx_res *res = data;
	struct drm_ctx ctx;
	int i;

	if (res->count >= DRM_RESERVED_CONTEXTS) {
		memset(&ctx, 0, sizeof(ctx));
		for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
			ctx.handle = i;
			if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx)))
				return -EFAULT;
		}
	}
	res->count = DRM_RESERVED_CONTEXTS;

	return 0;
}

/**
 * Add context.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx structure.
 * \return zero on success or a negative number on failure.
 *
 * Get a new handle for the context and copy to userspace.
 */
int drm_addctx(struct drm_device *dev, void *data,
	       struct drm_file *file_priv)
{
	struct drm_ctx_list *ctx_entry;
	struct drm_ctx *ctx = data;

	ctx->handle = drm_ctxbitmap_next(dev);
	if (ctx->handle == DRM_KERNEL_CONTEXT) {
		/* Skip kernel's context and get a new one. */
		ctx->handle = drm_ctxbitmap_next(dev);
	}
	DRM_DEBUG("%d\n", ctx->handle);
	if (ctx->handle == -1) {
		DRM_DEBUG("Not enough free contexts.\n");
		/* Should this return -EBUSY instead? */
		return -ENOMEM;
	}

	if (ctx->handle != DRM_KERNEL_CONTEXT) {
		if (dev->driver->context_ctor)
			if (!dev->driver->context_ctor(dev, ctx->handle)) {
				DRM_DEBUG("Running out of ctxs or memory.\n");
				return -ENOMEM;
			}
	}

	ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL);
	if (!ctx_entry) {
		DRM_DEBUG("out of memory\n");
		return -ENOMEM;
	}

	INIT_LIST_HEAD(&ctx_entry->head);
	ctx_entry->handle = ctx->handle;
	ctx_entry->tag = file_priv;

	mutex_lock(&dev->ctxlist_mutex);
	list_add(&ctx_entry->head, &dev->ctxlist);
	++dev->ctx_count;
	mutex_unlock(&dev->ctxlist_mutex);

	return 0;
}

int drm_modctx(struct drm_device *dev, void *data, struct drm_file *file_priv)
{
	/* This does nothing */
	return 0;
}

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

	/* This is 0, because we don't handle any context flags */
	ctx->flags = 0;

	return 0;
}

/**
 * Switch context.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx structure.
 * \return zero on success or a negative number on failure.
 *
 * Calls context_switch().
 */
int drm_switchctx(struct drm_device *dev, void *data,
		  struct drm_file *file_priv)
{
	struct drm_ctx *ctx = data;

	DRM_DEBUG("%d\n", ctx->handle);
	return drm_context_switch(dev, dev->last_context, ctx->handle);
}

/**
 * New context.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx structure.
 * \return zero on success or a negative number on failure.
 *
 * Calls context_switch_complete().
 */
int drm_newctx(struct drm_device *dev, void *data,
	       struct drm_file *file_priv)
{
	struct drm_ctx *ctx = data;

	DRM_DEBUG("%d\n", ctx->handle);
	drm_context_switch_complete(dev, file_priv, ctx->handle);

	return 0;
}

/**
 * Remove context.
 *
 * \param inode device inode.
 * \param file_priv DRM file private.
 * \param cmd command.
 * \param arg user argument pointing to a drm_ctx structure.
 * \return zero on success or a negative number on failure.
 *
 * If not the special kernel context, calls ctxbitmap_free() to free the specified context.
 */
int drm_rmctx(struct drm_device *dev, void *data,
	      struct drm_file *file_priv)
{
	struct drm_ctx *ctx = data;

	DRM_DEBUG("%d\n", ctx->handle);
	if (ctx->handle != DRM_KERNEL_CONTEXT) {
		if (dev->driver->context_dtor)
			dev->driver->context_dtor(dev, ctx->handle);
		drm_ctxbitmap_free(dev, ctx->handle);
	}

	mutex_lock(&dev->ctxlist_mutex);
	if (!list_empty(&dev->ctxlist)) {
		struct drm_ctx_list *pos, *n;

		list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
			if (pos->handle == ctx->handle) {
				list_del(&pos->head);
				kfree(pos);
				--dev->ctx_count;
			}
		}
	}
	mutex_unlock(&dev->ctxlist_mutex);

	return 0;
}

/*@}*/
Commit	Line	Data
1da177e4	1	/**
b5e89ed5	2	* \file drm_context.c
1da177e4	3	* IOCTLs for generic contexts
b5e89ed5	4	*
1da177e4 LT	5	* \author Rickard E. (Rik) Faith <faith@valinux.com>
	6	* \author Gareth Hughes <gareth@valinux.com>
	7	*/
	8
	9	/*
	10	* Created: Fri Nov 24 18:31:37 2000 by gareth@valinux.com
	11	*
	12	* Copyright 1999, 2000 Precision Insight, Inc., Cedar Park, Texas.
	13	* Copyright 2000 VA Linux Systems, Inc., Sunnyvale, California.
	14	* All Rights Reserved.
	15	*
	16	* Permission is hereby granted, free of charge, to any person obtaining a
	17	* copy of this software and associated documentation files (the "Software"),
	18	* to deal in the Software without restriction, including without limitation
	19	* the rights to use, copy, modify, merge, publish, distribute, sublicense,
	20	* and/or sell copies of the Software, and to permit persons to whom the
	21	* Software is furnished to do so, subject to the following conditions:
	22	*
	23	* The above copyright notice and this permission notice (including the next
	24	* paragraph) shall be included in all copies or substantial portions of the
	25	* Software.
	26	*
	27	* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	28	* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	29	* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
	30	* VA LINUX SYSTEMS AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
	31	* OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
	32	* ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
	33	* OTHER DEALINGS IN THE SOFTWARE.
	34	*/
	35
	36	/*
	37	* ChangeLog:
	38	* 2001-11-16 Torsten Duwe <duwe@caldera.de>
	39	* added context constructor/destructor hooks,
	40	* needed by SiS driver's memory management.
	41	*/
	42
	43	#include "drmP.h"
	44
	45	/******************************************************************/
	46	/** \name Context bitmap support */
	47	/@{/
	48
	49	/**
	50	* Free a handle from the context bitmap.
	51	*
	52	* \param dev DRM device.
	53	* \param ctx_handle context handle.
	54	*
	55	* Clears the bit specified by \p ctx_handle in drm_device::ctx_bitmap and the entry
62968144	56	* in drm_device::ctx_idr, while holding the drm_device::struct_mutex
1da177e4 LT	57	* lock.
1da177e4 LT	58	*/
84b1fd10	59	void drm_ctxbitmap_free(struct drm_device * dev, int ctx_handle)
1da177e4	60	{
62968144 DA	61	mutex_lock(&dev->struct_mutex);
	62	idr_remove(&dev->ctx_idr, ctx_handle);
	63	mutex_unlock(&dev->struct_mutex);
1da177e4 LT	64	}
1da177e4 LT	65
b5e89ed5	66	/**
1da177e4 LT	67	* Context bitmap allocation.
	68	*
	69	* \param dev DRM device.
	70	* \return (non-negative) context handle on success or a negative number on failure.
	71	*
62968144	72	* Allocate a new idr from drm_device::ctx_idr while holding the
30e2fb18	73	* drm_device::struct_mutex lock.
1da177e4	74	*/
84b1fd10	75	static int drm_ctxbitmap_next(struct drm_device * dev)
1da177e4	76	{
62968144 DA	77	int new_id;
62968144 DA	78	int ret;
1da177e4	79
62968144 DA	80	again:
	81	if (idr_pre_get(&dev->ctx_idr, GFP_KERNEL) == 0) {
	82	DRM_ERROR("Out of memory expanding drawable idr\n");
	83	return -ENOMEM;
	84	}
30e2fb18	85	mutex_lock(&dev->struct_mutex);
62968144 DA	86	ret = idr_get_new_above(&dev->ctx_idr, NULL,
	87	DRM_RESERVED_CONTEXTS, &new_id);
	88	if (ret == -EAGAIN) {
30e2fb18	89	mutex_unlock(&dev->struct_mutex);
62968144	90	goto again;
1da177e4	91	}
30e2fb18	92	mutex_unlock(&dev->struct_mutex);
62968144	93	return new_id;
1da177e4 LT	94	}
	95
	96	/**
	97	* Context bitmap initialization.
	98	*
	99	* \param dev DRM device.
	100	*
62968144	101	* Initialise the drm_device::ctx_idr
1da177e4	102	*/
84b1fd10	103	int drm_ctxbitmap_init(struct drm_device * dev)
1da177e4	104	{
62968144	105	idr_init(&dev->ctx_idr);
1da177e4 LT	106	return 0;
	107	}
	108
	109	/**
	110	* Context bitmap cleanup.
	111	*
	112	* \param dev DRM device.
	113	*
62968144 DA	114	* Free all idr members using drm_ctx_sarea_free helper function
62968144 DA	115	* while holding the drm_device::struct_mutex lock.
1da177e4	116	*/
84b1fd10	117	void drm_ctxbitmap_cleanup(struct drm_device * dev)
1da177e4	118	{
30e2fb18	119	mutex_lock(&dev->struct_mutex);
62968144	120	idr_remove_all(&dev->ctx_idr);
30e2fb18	121	mutex_unlock(&dev->struct_mutex);
1da177e4 LT	122	}
	123
	124	/@}/
	125
	126	/******************************************************************/
	127	/** \name Per Context SAREA Support */
	128	/@{/
	129
	130	/**
	131	* Get per-context SAREA.
b5e89ed5	132	*
1da177e4	133	* \param inode device inode.
6c340eac	134	* \param file_priv DRM file private.
1da177e4 LT	135	* \param cmd command.
	136	* \param arg user argument pointing to a drm_ctx_priv_map structure.
	137	* \return zero on success or a negative number on failure.
	138	*
62968144	139	* Gets the map from drm_device::ctx_idr with the handle specified and
1da177e4 LT	140	* returns its handle.
1da177e4 LT	141	*/
c153f45f EA	142	int drm_getsareactx(struct drm_device dev, void data,
c153f45f EA	143	struct drm_file *file_priv)
1da177e4	144	{
c153f45f	145	struct drm_ctx_priv_map *request = data;
f77d390c	146	struct drm_local_map *map;
55910517	147	struct drm_map_list *_entry;
1da177e4	148
30e2fb18	149	mutex_lock(&dev->struct_mutex);
62968144	150
c153f45f	151	map = idr_find(&dev->ctx_idr, request->ctx_id);
62968144	152	if (!map) {
30e2fb18	153	mutex_unlock(&dev->struct_mutex);
1da177e4 LT	154	return -EINVAL;
	155	}
	156
30e2fb18	157	mutex_unlock(&dev->struct_mutex);
1da177e4	158
c153f45f	159	request->handle = NULL;
bd1b331f	160	list_for_each_entry(_entry, &dev->maplist, head) {
d1f2b55a	161	if (_entry->map == map) {
bc5f4523	162	request->handle =
b5e89ed5	163	(void *)(unsigned long)_entry->user_token;
d1f2b55a DA	164	break;
	165	}
	166	}
c153f45f	167	if (request->handle == NULL)
d1f2b55a DA	168	return -EINVAL;
d1f2b55a DA	169
1da177e4 LT	170	return 0;
	171	}
	172
	173	/**
	174	* Set per-context SAREA.
b5e89ed5	175	*
1da177e4	176	* \param inode device inode.
6c340eac	177	* \param file_priv DRM file private.
1da177e4 LT	178	* \param cmd command.
	179	* \param arg user argument pointing to a drm_ctx_priv_map structure.
	180	* \return zero on success or a negative number on failure.
	181	*
	182	* Searches the mapping specified in \p arg and update the entry in
62968144	183	* drm_device::ctx_idr with it.
1da177e4	184	*/
c153f45f EA	185	int drm_setsareactx(struct drm_device dev, void data,
c153f45f EA	186	struct drm_file *file_priv)
1da177e4	187	{
c153f45f	188	struct drm_ctx_priv_map *request = data;
f77d390c	189	struct drm_local_map *map = NULL;
55910517	190	struct drm_map_list *r_list = NULL;
1da177e4	191
30e2fb18	192	mutex_lock(&dev->struct_mutex);
bd1b331f	193	list_for_each_entry(r_list, &dev->maplist, head) {
9a186645	194	if (r_list->map
c153f45f	195	&& r_list->user_token == (unsigned long) request->handle)
1da177e4 LT	196	goto found;
1da177e4 LT	197	}
b5e89ed5	198	bad:
30e2fb18	199	mutex_unlock(&dev->struct_mutex);
1da177e4 LT	200	return -EINVAL;
1da177e4 LT	201
b5e89ed5	202	found:
1da177e4	203	map = r_list->map;
b5e89ed5 DA	204	if (!map)
b5e89ed5 DA	205	goto bad;
62968144	206
c153f45f	207	if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id)))
1da177e4	208	goto bad;
62968144	209
30e2fb18	210	mutex_unlock(&dev->struct_mutex);
c153f45f	211
1da177e4 LT	212	return 0;
	213	}
	214
	215	/@}/
	216
	217	/******************************************************************/
	218	/** \name The actual DRM context handling routines */
	219	/@{/
	220
	221	/**
	222	* Switch context.
	223	*
	224	* \param dev DRM device.
	225	* \param old old context handle.
	226	* \param new new context handle.
	227	* \return zero on success or a negative number on failure.
	228	*
	229	* Attempt to set drm_device::context_flag.
	230	*/
84b1fd10	231	static int drm_context_switch(struct drm_device * dev, int old, int new)
1da177e4	232	{
b5e89ed5 DA	233	if (test_and_set_bit(0, &dev->context_flag)) {
	234	DRM_ERROR("Reentering -- FIXME\n");
	235	return -EBUSY;
	236	}
1da177e4	237
b5e89ed5	238	DRM_DEBUG("Context switch from %d to %d\n", old, new);
1da177e4	239
b5e89ed5 DA	240	if (new == dev->last_context) {
	241	clear_bit(0, &dev->context_flag);
	242	return 0;
	243	}
1da177e4	244
b5e89ed5	245	return 0;
1da177e4 LT	246	}
	247
	248	/**
	249	* Complete context switch.
	250	*
	251	* \param dev DRM device.
	252	* \param new new context handle.
	253	* \return zero on success or a negative number on failure.
	254	*
	255	* Updates drm_device::last_context and drm_device::last_switch. Verifies the
	256	* hardware lock is held, clears the drm_device::context_flag and wakes up
	257	* drm_device::context_wait.
	258	*/
7c1c2871 DA	259	static int drm_context_switch_complete(struct drm_device *dev,
7c1c2871 DA	260	struct drm_file *file_priv, int new)
1da177e4	261	{
b5e89ed5 DA	262	dev->last_context = new; /* PRE/POST: This is the _only_ writer. */
b5e89ed5 DA	263	dev->last_switch = jiffies;
1da177e4	264
7c1c2871	265	if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) {
b5e89ed5 DA	266	DRM_ERROR("Lock isn't held after context switch\n");
b5e89ed5 DA	267	}
1da177e4	268
b5e89ed5 DA	269	/* If a context switch is ever initiated
	270	when the kernel holds the lock, release
	271	that lock here. */
	272	clear_bit(0, &dev->context_flag);
	273	wake_up(&dev->context_wait);
1da177e4	274
b5e89ed5	275	return 0;
1da177e4 LT	276	}
	277
	278	/**
	279	* Reserve contexts.
	280	*
	281	* \param inode device inode.
6c340eac	282	* \param file_priv DRM file private.
1da177e4 LT	283	* \param cmd command.
	284	* \param arg user argument pointing to a drm_ctx_res structure.
	285	* \return zero on success or a negative number on failure.
	286	*/
c153f45f EA	287	int drm_resctx(struct drm_device dev, void data,
c153f45f EA	288	struct drm_file *file_priv)
1da177e4	289	{
c153f45f	290	struct drm_ctx_res *res = data;
c60ce623	291	struct drm_ctx ctx;
1da177e4 LT	292	int i;
1da177e4 LT	293
c153f45f	294	if (res->count >= DRM_RESERVED_CONTEXTS) {
b5e89ed5 DA	295	memset(&ctx, 0, sizeof(ctx));
b5e89ed5 DA	296	for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
1da177e4	297	ctx.handle = i;
c153f45f	298	if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx)))
1da177e4 LT	299	return -EFAULT;
	300	}
	301	}
c153f45f	302	res->count = DRM_RESERVED_CONTEXTS;
1da177e4	303
1da177e4 LT	304	return 0;
	305	}
	306
	307	/**
	308	* Add context.
	309	*
	310	* \param inode device inode.
6c340eac	311	* \param file_priv DRM file private.
1da177e4 LT	312	* \param cmd command.
	313	* \param arg user argument pointing to a drm_ctx structure.
	314	* \return zero on success or a negative number on failure.
	315	*
	316	* Get a new handle for the context and copy to userspace.
	317	*/
c153f45f EA	318	int drm_addctx(struct drm_device dev, void data,
c153f45f EA	319	struct drm_file *file_priv)
1da177e4	320	{
55910517	321	struct drm_ctx_list *ctx_entry;
c153f45f	322	struct drm_ctx *ctx = data;
1da177e4	323
c153f45f EA	324	ctx->handle = drm_ctxbitmap_next(dev);
c153f45f EA	325	if (ctx->handle == DRM_KERNEL_CONTEXT) {
b5e89ed5	326	/* Skip kernel's context and get a new one. */
c153f45f	327	ctx->handle = drm_ctxbitmap_next(dev);
1da177e4	328	}
c153f45f EA	329	DRM_DEBUG("%d\n", ctx->handle);
c153f45f EA	330	if (ctx->handle == -1) {
b5e89ed5 DA	331	DRM_DEBUG("Not enough free contexts.\n");
b5e89ed5 DA	332	/* Should this return -EBUSY instead? */
1da177e4 LT	333	return -ENOMEM;
	334	}
	335
c153f45f	336	if (ctx->handle != DRM_KERNEL_CONTEXT) {
1da177e4	337	if (dev->driver->context_ctor)
c153f45f	338	if (!dev->driver->context_ctor(dev, ctx->handle)) {
b5e9fc13 DA	339	DRM_DEBUG("Running out of ctxs or memory.\n");
	340	return -ENOMEM;
	341	}
1da177e4 LT	342	}
1da177e4 LT	343
9a298b2a	344	ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL);
b5e89ed5	345	if (!ctx_entry) {
1da177e4 LT	346	DRM_DEBUG("out of memory\n");
	347	return -ENOMEM;
	348	}
	349
b5e89ed5	350	INIT_LIST_HEAD(&ctx_entry->head);
c153f45f	351	ctx_entry->handle = ctx->handle;
6c340eac	352	ctx_entry->tag = file_priv;
1da177e4	353
30e2fb18	354	mutex_lock(&dev->ctxlist_mutex);
bd1b331f	355	list_add(&ctx_entry->head, &dev->ctxlist);
1da177e4	356	++dev->ctx_count;
30e2fb18	357	mutex_unlock(&dev->ctxlist_mutex);
1da177e4	358
1da177e4 LT	359	return 0;
	360	}
	361
c153f45f	362	int drm_modctx(struct drm_device dev, void data, struct drm_file *file_priv)
1da177e4 LT	363	{
	364	/* This does nothing */
	365	return 0;
	366	}
	367
	368	/**
	369	* Get context.
	370	*
	371	* \param inode device inode.
6c340eac	372	* \param file_priv DRM file private.
1da177e4 LT	373	* \param cmd command.
	374	* \param arg user argument pointing to a drm_ctx structure.
	375	* \return zero on success or a negative number on failure.
	376	*/
c153f45f	377	int drm_getctx(struct drm_device dev, void data, struct drm_file *file_priv)
1da177e4	378	{
c153f45f	379	struct drm_ctx *ctx = data;
1da177e4 LT	380
1da177e4 LT	381	/* This is 0, because we don't handle any context flags */
c153f45f	382	ctx->flags = 0;
1da177e4	383
1da177e4 LT	384	return 0;
	385	}
	386
	387	/**
	388	* Switch context.
	389	*
	390	* \param inode device inode.
6c340eac	391	* \param file_priv DRM file private.
1da177e4 LT	392	* \param cmd command.
	393	* \param arg user argument pointing to a drm_ctx structure.
	394	* \return zero on success or a negative number on failure.
	395	*
	396	* Calls context_switch().
	397	*/
c153f45f EA	398	int drm_switchctx(struct drm_device dev, void data,
c153f45f EA	399	struct drm_file *file_priv)
1da177e4	400	{
c153f45f	401	struct drm_ctx *ctx = data;
1da177e4	402
c153f45f EA	403	DRM_DEBUG("%d\n", ctx->handle);
c153f45f EA	404	return drm_context_switch(dev, dev->last_context, ctx->handle);
1da177e4 LT	405	}
	406
	407	/**
	408	* New context.
	409	*
	410	* \param inode device inode.
6c340eac	411	* \param file_priv DRM file private.
1da177e4 LT	412	* \param cmd command.
	413	* \param arg user argument pointing to a drm_ctx structure.
	414	* \return zero on success or a negative number on failure.
	415	*
	416	* Calls context_switch_complete().
	417	*/
c153f45f EA	418	int drm_newctx(struct drm_device dev, void data,
c153f45f EA	419	struct drm_file *file_priv)
1da177e4	420	{
c153f45f	421	struct drm_ctx *ctx = data;
1da177e4	422
c153f45f	423	DRM_DEBUG("%d\n", ctx->handle);
7c1c2871	424	drm_context_switch_complete(dev, file_priv, ctx->handle);
1da177e4 LT	425
	426	return 0;
	427	}
	428
	429	/**
	430	* Remove context.
	431	*
	432	* \param inode device inode.
6c340eac	433	* \param file_priv DRM file private.
1da177e4 LT	434	* \param cmd command.
	435	* \param arg user argument pointing to a drm_ctx structure.
	436	* \return zero on success or a negative number on failure.
	437	*
	438	* If not the special kernel context, calls ctxbitmap_free() to free the specified context.
	439	*/
c153f45f EA	440	int drm_rmctx(struct drm_device dev, void data,
c153f45f EA	441	struct drm_file *file_priv)
1da177e4	442	{
c153f45f	443	struct drm_ctx *ctx = data;
1da177e4	444
c153f45f	445	DRM_DEBUG("%d\n", ctx->handle);
c153f45f	446	if (ctx->handle != DRM_KERNEL_CONTEXT) {
1da177e4	447	if (dev->driver->context_dtor)
c153f45f EA	448	dev->driver->context_dtor(dev, ctx->handle);
c153f45f EA	449	drm_ctxbitmap_free(dev, ctx->handle);
1da177e4 LT	450	}
1da177e4 LT	451
30e2fb18	452	mutex_lock(&dev->ctxlist_mutex);
bd1b331f	453	if (!list_empty(&dev->ctxlist)) {
55910517	454	struct drm_ctx_list pos, n;
1da177e4	455
bd1b331f	456	list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
c153f45f	457	if (pos->handle == ctx->handle) {
b5e89ed5	458	list_del(&pos->head);
9a298b2a	459	kfree(pos);
1da177e4 LT	460	--dev->ctx_count;
	461	}
	462	}
	463	}
30e2fb18	464	mutex_unlock(&dev->ctxlist_mutex);
1da177e4 LT	465
	466	return 0;
	467	}
	468
	469	/@}/