[deliverable/linux.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 <drm/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 ret;

	mutex_lock(&dev->struct_mutex);
	ret = idr_alloc(&dev->ctx_idr, NULL, DRM_RESERVED_CONTEXTS, 0,
			GFP_KERNEL);
	mutex_unlock(&dev->struct_mutex);
	return ret;
}

/**
 * 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_destroy(&dev->ctx_idr);
	mutex_unlock(&dev->struct_mutex);
}

/**
 * drm_ctxbitmap_flush() - Flush all contexts owned by a file
 * @dev: DRM device to operate on
 * @file: Open file to flush contexts for
 *
 * This iterates over all contexts on @dev and drops them if they're owned by
 * @file. Note that after this call returns, new contexts might be added if
 * the file is still alive.
 */
void drm_ctxbitmap_flush(struct drm_device *dev, struct drm_file *file)
{
	struct drm_ctx_list *pos, *tmp;

	mutex_lock(&dev->ctxlist_mutex);

	list_for_each_entry_safe(pos, tmp, &dev->ctxlist, head) {
		if (pos->tag == file &&
		    pos->handle != DRM_KERNEL_CONTEXT) {
			if (dev->driver->context_dtor)
				dev->driver->context_dtor(dev, pos->handle);

			drm_ctxbitmap_free(dev, pos->handle);
			list_del(&pos->head);
			kfree(pos);
		}
	}

	mutex_unlock(&dev->ctxlist_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;
	}

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

	mutex_unlock(&dev->struct_mutex);

	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. */

	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);

	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;
	}

	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);
	mutex_unlock(&dev->ctxlist_mutex);

	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);
			}
		}
	}
	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
760285e7	43	#include <drm/drmP.h>
1da177e4	44
c21eb21c DA	45	/******************************************************************/
	46	/** \name Context bitmap support */
	47	/@{/
	48
1da177e4 LT	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	*/
c21eb21c	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	77	int ret;
1da177e4	78
30e2fb18	79	mutex_lock(&dev->struct_mutex);
2e928815 TH	80	ret = idr_alloc(&dev->ctx_idr, NULL, DRM_RESERVED_CONTEXTS, 0,
2e928815 TH	81	GFP_KERNEL);
30e2fb18	82	mutex_unlock(&dev->struct_mutex);
2e928815	83	return ret;
1da177e4 LT	84	}
	85
	86	/**
	87	* Context bitmap initialization.
	88	*
	89	* \param dev DRM device.
	90	*
62968144	91	* Initialise the drm_device::ctx_idr
1da177e4	92	*/
c21eb21c	93	int drm_ctxbitmap_init(struct drm_device * dev)
1da177e4	94	{
62968144	95	idr_init(&dev->ctx_idr);
c21eb21c	96	return 0;
1da177e4 LT	97	}
	98
	99	/**
	100	* Context bitmap cleanup.
	101	*
	102	* \param dev DRM device.
	103	*
62968144 DA	104	* Free all idr members using drm_ctx_sarea_free helper function
62968144 DA	105	* while holding the drm_device::struct_mutex lock.
1da177e4	106	*/
c21eb21c	107	void drm_ctxbitmap_cleanup(struct drm_device * dev)
1da177e4	108	{
30e2fb18	109	mutex_lock(&dev->struct_mutex);
4d53233a	110	idr_destroy(&dev->ctx_idr);
30e2fb18	111	mutex_unlock(&dev->struct_mutex);
1da177e4 LT	112	}
1da177e4 LT	113
9f8d21ea DH	114	/**
	115	* drm_ctxbitmap_flush() - Flush all contexts owned by a file
	116	* @dev: DRM device to operate on
	117	* @file: Open file to flush contexts for
	118	*
	119	* This iterates over all contexts on @dev and drops them if they're owned by
	120	* @file. Note that after this call returns, new contexts might be added if
	121	* the file is still alive.
	122	*/
	123	void drm_ctxbitmap_flush(struct drm_device dev, struct drm_file file)
	124	{
	125	struct drm_ctx_list pos, tmp;
	126
	127	mutex_lock(&dev->ctxlist_mutex);
	128
	129	list_for_each_entry_safe(pos, tmp, &dev->ctxlist, head) {
	130	if (pos->tag == file &&
	131	pos->handle != DRM_KERNEL_CONTEXT) {
	132	if (dev->driver->context_dtor)
	133	dev->driver->context_dtor(dev, pos->handle);
	134
	135	drm_ctxbitmap_free(dev, pos->handle);
	136	list_del(&pos->head);
	137	kfree(pos);
	138	}
	139	}
	140
	141	mutex_unlock(&dev->ctxlist_mutex);
	142	}
	143
1da177e4 LT	144	/@}/
	145
	146	/******************************************************************/
	147	/** \name Per Context SAREA Support */
	148	/@{/
	149
	150	/**
	151	* Get per-context SAREA.
b5e89ed5	152	*
1da177e4	153	* \param inode device inode.
6c340eac	154	* \param file_priv DRM file private.
1da177e4 LT	155	* \param cmd command.
	156	* \param arg user argument pointing to a drm_ctx_priv_map structure.
	157	* \return zero on success or a negative number on failure.
	158	*
62968144	159	* Gets the map from drm_device::ctx_idr with the handle specified and
1da177e4 LT	160	* returns its handle.
1da177e4 LT	161	*/
c153f45f EA	162	int drm_getsareactx(struct drm_device dev, void data,
c153f45f EA	163	struct drm_file *file_priv)
1da177e4	164	{
c153f45f	165	struct drm_ctx_priv_map *request = data;
f77d390c	166	struct drm_local_map *map;
55910517	167	struct drm_map_list *_entry;
1da177e4	168
30e2fb18	169	mutex_lock(&dev->struct_mutex);
62968144	170
c153f45f	171	map = idr_find(&dev->ctx_idr, request->ctx_id);
62968144	172	if (!map) {
30e2fb18	173	mutex_unlock(&dev->struct_mutex);
1da177e4 LT	174	return -EINVAL;
	175	}
	176
c153f45f	177	request->handle = NULL;
bd1b331f	178	list_for_each_entry(_entry, &dev->maplist, head) {
d1f2b55a	179	if (_entry->map == map) {
bc5f4523	180	request->handle =
b5e89ed5	181	(void *)(unsigned long)_entry->user_token;
d1f2b55a DA	182	break;
	183	}
	184	}
09b4ea47 IH	185
	186	mutex_unlock(&dev->struct_mutex);
	187
c153f45f	188	if (request->handle == NULL)
d1f2b55a DA	189	return -EINVAL;
d1f2b55a DA	190
1da177e4 LT	191	return 0;
	192	}
	193
	194	/**
	195	* Set per-context SAREA.
b5e89ed5	196	*
1da177e4	197	* \param inode device inode.
6c340eac	198	* \param file_priv DRM file private.
1da177e4 LT	199	* \param cmd command.
	200	* \param arg user argument pointing to a drm_ctx_priv_map structure.
	201	* \return zero on success or a negative number on failure.
	202	*
	203	* Searches the mapping specified in \p arg and update the entry in
62968144	204	* drm_device::ctx_idr with it.
1da177e4	205	*/
c153f45f EA	206	int drm_setsareactx(struct drm_device dev, void data,
c153f45f EA	207	struct drm_file *file_priv)
1da177e4	208	{
c153f45f	209	struct drm_ctx_priv_map *request = data;
f77d390c	210	struct drm_local_map *map = NULL;
55910517	211	struct drm_map_list *r_list = NULL;
1da177e4	212
30e2fb18	213	mutex_lock(&dev->struct_mutex);
bd1b331f	214	list_for_each_entry(r_list, &dev->maplist, head) {
9a186645	215	if (r_list->map
c153f45f	216	&& r_list->user_token == (unsigned long) request->handle)
1da177e4 LT	217	goto found;
1da177e4 LT	218	}
b5e89ed5	219	bad:
30e2fb18	220	mutex_unlock(&dev->struct_mutex);
1da177e4 LT	221	return -EINVAL;
1da177e4 LT	222
b5e89ed5	223	found:
1da177e4	224	map = r_list->map;
b5e89ed5 DA	225	if (!map)
b5e89ed5 DA	226	goto bad;
62968144	227
c153f45f	228	if (IS_ERR(idr_replace(&dev->ctx_idr, map, request->ctx_id)))
1da177e4	229	goto bad;
62968144	230
30e2fb18	231	mutex_unlock(&dev->struct_mutex);
c153f45f	232
1da177e4 LT	233	return 0;
	234	}
	235
	236	/@}/
	237
	238	/******************************************************************/
	239	/** \name The actual DRM context handling routines */
	240	/@{/
	241
	242	/**
	243	* Switch context.
	244	*
	245	* \param dev DRM device.
	246	* \param old old context handle.
	247	* \param new new context handle.
	248	* \return zero on success or a negative number on failure.
	249	*
	250	* Attempt to set drm_device::context_flag.
	251	*/
84b1fd10	252	static int drm_context_switch(struct drm_device * dev, int old, int new)
1da177e4	253	{
b5e89ed5 DA	254	if (test_and_set_bit(0, &dev->context_flag)) {
	255	DRM_ERROR("Reentering -- FIXME\n");
	256	return -EBUSY;
	257	}
1da177e4	258
b5e89ed5	259	DRM_DEBUG("Context switch from %d to %d\n", old, new);
1da177e4	260
b5e89ed5 DA	261	if (new == dev->last_context) {
	262	clear_bit(0, &dev->context_flag);
	263	return 0;
	264	}
1da177e4	265
b5e89ed5	266	return 0;
1da177e4 LT	267	}
	268
	269	/**
	270	* Complete context switch.
	271	*
	272	* \param dev DRM device.
	273	* \param new new context handle.
	274	* \return zero on success or a negative number on failure.
	275	*
	276	* Updates drm_device::last_context and drm_device::last_switch. Verifies the
	277	* hardware lock is held, clears the drm_device::context_flag and wakes up
	278	* drm_device::context_wait.
	279	*/
7c1c2871 DA	280	static int drm_context_switch_complete(struct drm_device *dev,
7c1c2871 DA	281	struct drm_file *file_priv, int new)
1da177e4	282	{
b5e89ed5	283	dev->last_context = new; /* PRE/POST: This is the _only_ writer. */
1da177e4	284
7c1c2871	285	if (!_DRM_LOCK_IS_HELD(file_priv->master->lock.hw_lock->lock)) {
b5e89ed5 DA	286	DRM_ERROR("Lock isn't held after context switch\n");
b5e89ed5 DA	287	}
1da177e4	288
b5e89ed5 DA	289	/* If a context switch is ever initiated
	290	when the kernel holds the lock, release
	291	that lock here. */
	292	clear_bit(0, &dev->context_flag);
1da177e4	293
b5e89ed5	294	return 0;
1da177e4 LT	295	}
	296
	297	/**
	298	* Reserve contexts.
	299	*
	300	* \param inode device inode.
6c340eac	301	* \param file_priv DRM file private.
1da177e4 LT	302	* \param cmd command.
	303	* \param arg user argument pointing to a drm_ctx_res structure.
	304	* \return zero on success or a negative number on failure.
	305	*/
c153f45f EA	306	int drm_resctx(struct drm_device dev, void data,
c153f45f EA	307	struct drm_file *file_priv)
1da177e4	308	{
c153f45f	309	struct drm_ctx_res *res = data;
c60ce623	310	struct drm_ctx ctx;
1da177e4 LT	311	int i;
1da177e4 LT	312
c153f45f	313	if (res->count >= DRM_RESERVED_CONTEXTS) {
b5e89ed5 DA	314	memset(&ctx, 0, sizeof(ctx));
b5e89ed5 DA	315	for (i = 0; i < DRM_RESERVED_CONTEXTS; i++) {
1da177e4	316	ctx.handle = i;
c153f45f	317	if (copy_to_user(&res->contexts[i], &ctx, sizeof(ctx)))
1da177e4 LT	318	return -EFAULT;
	319	}
	320	}
c153f45f	321	res->count = DRM_RESERVED_CONTEXTS;
1da177e4	322
1da177e4 LT	323	return 0;
	324	}
	325
	326	/**
	327	* Add context.
	328	*
	329	* \param inode device inode.
6c340eac	330	* \param file_priv DRM file private.
1da177e4 LT	331	* \param cmd command.
	332	* \param arg user argument pointing to a drm_ctx structure.
	333	* \return zero on success or a negative number on failure.
	334	*
	335	* Get a new handle for the context and copy to userspace.
	336	*/
c153f45f EA	337	int drm_addctx(struct drm_device dev, void data,
c153f45f EA	338	struct drm_file *file_priv)
1da177e4	339	{
55910517	340	struct drm_ctx_list *ctx_entry;
c153f45f	341	struct drm_ctx *ctx = data;
1da177e4	342
c153f45f EA	343	ctx->handle = drm_ctxbitmap_next(dev);
c153f45f EA	344	if (ctx->handle == DRM_KERNEL_CONTEXT) {
b5e89ed5	345	/* Skip kernel's context and get a new one. */
c153f45f	346	ctx->handle = drm_ctxbitmap_next(dev);
1da177e4	347	}
c153f45f EA	348	DRM_DEBUG("%d\n", ctx->handle);
c153f45f EA	349	if (ctx->handle == -1) {
b5e89ed5 DA	350	DRM_DEBUG("Not enough free contexts.\n");
b5e89ed5 DA	351	/* Should this return -EBUSY instead? */
1da177e4 LT	352	return -ENOMEM;
	353	}
	354
9a298b2a	355	ctx_entry = kmalloc(sizeof(*ctx_entry), GFP_KERNEL);
b5e89ed5	356	if (!ctx_entry) {
1da177e4 LT	357	DRM_DEBUG("out of memory\n");
	358	return -ENOMEM;
	359	}
	360
b5e89ed5	361	INIT_LIST_HEAD(&ctx_entry->head);
c153f45f	362	ctx_entry->handle = ctx->handle;
6c340eac	363	ctx_entry->tag = file_priv;
1da177e4	364
30e2fb18	365	mutex_lock(&dev->ctxlist_mutex);
bd1b331f	366	list_add(&ctx_entry->head, &dev->ctxlist);
30e2fb18	367	mutex_unlock(&dev->ctxlist_mutex);
1da177e4	368
1da177e4 LT	369	return 0;
	370	}
	371
1da177e4 LT	372	/**
	373	* Get context.
	374	*
	375	* \param inode device inode.
6c340eac	376	* \param file_priv DRM file private.
1da177e4 LT	377	* \param cmd command.
	378	* \param arg user argument pointing to a drm_ctx structure.
	379	* \return zero on success or a negative number on failure.
	380	*/
c153f45f	381	int drm_getctx(struct drm_device dev, void data, struct drm_file *file_priv)
1da177e4	382	{
c153f45f	383	struct drm_ctx *ctx = data;
1da177e4 LT	384
1da177e4 LT	385	/* This is 0, because we don't handle any context flags */
c153f45f	386	ctx->flags = 0;
1da177e4	387
1da177e4 LT	388	return 0;
	389	}
	390
	391	/**
	392	* Switch context.
	393	*
	394	* \param inode device inode.
6c340eac	395	* \param file_priv DRM file private.
1da177e4 LT	396	* \param cmd command.
	397	* \param arg user argument pointing to a drm_ctx structure.
	398	* \return zero on success or a negative number on failure.
	399	*
	400	* Calls context_switch().
	401	*/
c153f45f EA	402	int drm_switchctx(struct drm_device dev, void data,
c153f45f EA	403	struct drm_file *file_priv)
1da177e4	404	{
c153f45f	405	struct drm_ctx *ctx = data;
1da177e4	406
c153f45f EA	407	DRM_DEBUG("%d\n", ctx->handle);
c153f45f EA	408	return drm_context_switch(dev, dev->last_context, ctx->handle);
1da177e4 LT	409	}
	410
	411	/**
	412	* New context.
	413	*
	414	* \param inode device inode.
6c340eac	415	* \param file_priv DRM file private.
1da177e4 LT	416	* \param cmd command.
	417	* \param arg user argument pointing to a drm_ctx structure.
	418	* \return zero on success or a negative number on failure.
	419	*
	420	* Calls context_switch_complete().
	421	*/
c153f45f EA	422	int drm_newctx(struct drm_device dev, void data,
c153f45f EA	423	struct drm_file *file_priv)
1da177e4	424	{
c153f45f	425	struct drm_ctx *ctx = data;
1da177e4	426
c153f45f	427	DRM_DEBUG("%d\n", ctx->handle);
7c1c2871	428	drm_context_switch_complete(dev, file_priv, ctx->handle);
1da177e4 LT	429
	430	return 0;
	431	}
	432
	433	/**
	434	* Remove context.
	435	*
	436	* \param inode device inode.
6c340eac	437	* \param file_priv DRM file private.
1da177e4 LT	438	* \param cmd command.
	439	* \param arg user argument pointing to a drm_ctx structure.
	440	* \return zero on success or a negative number on failure.
	441	*
	442	* If not the special kernel context, calls ctxbitmap_free() to free the specified context.
	443	*/
c153f45f EA	444	int drm_rmctx(struct drm_device dev, void data,
c153f45f EA	445	struct drm_file *file_priv)
1da177e4	446	{
c153f45f	447	struct drm_ctx *ctx = data;
1da177e4	448
c153f45f	449	DRM_DEBUG("%d\n", ctx->handle);
c153f45f	450	if (ctx->handle != DRM_KERNEL_CONTEXT) {
1da177e4	451	if (dev->driver->context_dtor)
c153f45f EA	452	dev->driver->context_dtor(dev, ctx->handle);
c153f45f EA	453	drm_ctxbitmap_free(dev, ctx->handle);
1da177e4 LT	454	}
1da177e4 LT	455
30e2fb18	456	mutex_lock(&dev->ctxlist_mutex);
bd1b331f	457	if (!list_empty(&dev->ctxlist)) {
55910517	458	struct drm_ctx_list pos, n;
1da177e4	459
bd1b331f	460	list_for_each_entry_safe(pos, n, &dev->ctxlist, head) {
c153f45f	461	if (pos->handle == ctx->handle) {
b5e89ed5	462	list_del(&pos->head);
9a298b2a	463	kfree(pos);
1da177e4 LT	464	}
	465	}
	466	}
30e2fb18	467	mutex_unlock(&dev->ctxlist_mutex);
1da177e4 LT	468
	469	return 0;
	470	}
	471
	472	/@}/