[linux-block.git] / drivers / accel / drm_accel.c

// SPDX-License-Identifier: GPL-2.0

/*
 * Copyright 2022 HabanaLabs, Ltd.
 * All Rights Reserved.
 *
 */

#include <linux/debugfs.h>
#include <linux/device.h>
#include <linux/idr.h>

#include <drm/drm_accel.h>
#include <drm/drm_debugfs.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
#include <drm/drm_ioctl.h>
#include <drm/drm_print.h>

static DEFINE_SPINLOCK(accel_minor_lock);
static struct idr accel_minors_idr;

static struct dentry *accel_debugfs_root;
static struct class *accel_class;

static struct device_type accel_sysfs_device_minor = {
	.name = "accel_minor"
};

static char *accel_devnode(const struct device *dev, umode_t *mode)
{
	return kasprintf(GFP_KERNEL, "accel/%s", dev_name(dev));
}

static int accel_sysfs_init(void)
{
	accel_class = class_create(THIS_MODULE, "accel");
	if (IS_ERR(accel_class))
		return PTR_ERR(accel_class);

	accel_class->devnode = accel_devnode;

	return 0;
}

static void accel_sysfs_destroy(void)
{
	if (IS_ERR_OR_NULL(accel_class))
		return;
	class_destroy(accel_class);
	accel_class = NULL;
}

static int accel_name_info(struct seq_file *m, void *data)
{
	struct drm_info_node *node = (struct drm_info_node *) m->private;
	struct drm_minor *minor = node->minor;
	struct drm_device *dev = minor->dev;
	struct drm_master *master;

	mutex_lock(&dev->master_mutex);
	master = dev->master;
	seq_printf(m, "%s", dev->driver->name);
	if (dev->dev)
		seq_printf(m, " dev=%s", dev_name(dev->dev));
	if (master && master->unique)
		seq_printf(m, " master=%s", master->unique);
	if (dev->unique)
		seq_printf(m, " unique=%s", dev->unique);
	seq_puts(m, "\n");
	mutex_unlock(&dev->master_mutex);

	return 0;
}

static const struct drm_info_list accel_debugfs_list[] = {
	{"name", accel_name_info, 0}
};
#define ACCEL_DEBUGFS_ENTRIES ARRAY_SIZE(accel_debugfs_list)

/**
 * accel_debugfs_init() - Initialize debugfs for accel minor
 * @minor: Pointer to the drm_minor instance.
 * @minor_id: The minor's id
 *
 * This function initializes the drm minor's debugfs members and creates
 * a root directory for the minor in debugfs. It also creates common files
 * for accelerators and calls the driver's debugfs init callback.
 */
void accel_debugfs_init(struct drm_minor *minor, int minor_id)
{
	struct drm_device *dev = minor->dev;
	char name[64];

	INIT_LIST_HEAD(&minor->debugfs_list);
	mutex_init(&minor->debugfs_lock);
	sprintf(name, "%d", minor_id);
	minor->debugfs_root = debugfs_create_dir(name, accel_debugfs_root);

	drm_debugfs_create_files(accel_debugfs_list, ACCEL_DEBUGFS_ENTRIES,
				 minor->debugfs_root, minor);

	if (dev->driver->debugfs_init)
		dev->driver->debugfs_init(minor);
}

/**
 * accel_set_device_instance_params() - Set some device parameters for accel device
 * @kdev: Pointer to the device instance.
 * @index: The minor's index
 *
 * This function creates the dev_t of the device using the accel major and
 * the device's minor number. In addition, it sets the class and type of the
 * device instance to the accel sysfs class and device type, respectively.
 */
void accel_set_device_instance_params(struct device *kdev, int index)
{
	kdev->devt = MKDEV(ACCEL_MAJOR, index);
	kdev->class = accel_class;
	kdev->type = &accel_sysfs_device_minor;
}

/**
 * accel_minor_alloc() - Allocates a new accel minor
 *
 * This function access the accel minors idr and allocates from it
 * a new id to represent a new accel minor
 *
 * Return: A new id on success or error code in case idr_alloc failed
 */
int accel_minor_alloc(void)
{
	unsigned long flags;
	int r;

	spin_lock_irqsave(&accel_minor_lock, flags);
	r = idr_alloc(&accel_minors_idr, NULL, 0, ACCEL_MAX_MINORS, GFP_NOWAIT);
	spin_unlock_irqrestore(&accel_minor_lock, flags);

	return r;
}

/**
 * accel_minor_remove() - Remove an accel minor
 * @index: The minor id to remove.
 *
 * This function access the accel minors idr and removes from
 * it the member with the id that is passed to this function.
 */
void accel_minor_remove(int index)
{
	unsigned long flags;

	spin_lock_irqsave(&accel_minor_lock, flags);
	idr_remove(&accel_minors_idr, index);
	spin_unlock_irqrestore(&accel_minor_lock, flags);
}

/**
 * accel_minor_replace() - Replace minor pointer in accel minors idr.
 * @minor: Pointer to the new minor.
 * @index: The minor id to replace.
 *
 * This function access the accel minors idr structure and replaces the pointer
 * that is associated with an existing id. Because the minor pointer can be
 * NULL, we need to explicitly pass the index.
 *
 * Return: 0 for success, negative value for error
 */
void accel_minor_replace(struct drm_minor *minor, int index)
{
	unsigned long flags;

	spin_lock_irqsave(&accel_minor_lock, flags);
	idr_replace(&accel_minors_idr, minor, index);
	spin_unlock_irqrestore(&accel_minor_lock, flags);
}

/*
 * Looks up the given minor-ID and returns the respective DRM-minor object. The
 * refence-count of the underlying device is increased so you must release this
 * object with accel_minor_release().
 *
 * The object can be only a drm_minor that represents an accel device.
 *
 * As long as you hold this minor, it is guaranteed that the object and the
 * minor->dev pointer will stay valid! However, the device may get unplugged and
 * unregistered while you hold the minor.
 */
static struct drm_minor *accel_minor_acquire(unsigned int minor_id)
{
	struct drm_minor *minor;
	unsigned long flags;

	spin_lock_irqsave(&accel_minor_lock, flags);
	minor = idr_find(&accel_minors_idr, minor_id);
	if (minor)
		drm_dev_get(minor->dev);
	spin_unlock_irqrestore(&accel_minor_lock, flags);

	if (!minor) {
		return ERR_PTR(-ENODEV);
	} else if (drm_dev_is_unplugged(minor->dev)) {
		drm_dev_put(minor->dev);
		return ERR_PTR(-ENODEV);
	}

	return minor;
}

static void accel_minor_release(struct drm_minor *minor)
{
	drm_dev_put(minor->dev);
}

/**
 * accel_open - open method for ACCEL file
 * @inode: device inode
 * @filp: file pointer.
 *
 * This function must be used by drivers as their &file_operations.open method.
 * It looks up the correct ACCEL device and instantiates all the per-file
 * resources for it. It also calls the &drm_driver.open driver callback.
 *
 * Return: 0 on success or negative errno value on failure.
 */
int accel_open(struct inode *inode, struct file *filp)
{
	struct drm_device *dev;
	struct drm_minor *minor;
	int retcode;

	minor = accel_minor_acquire(iminor(inode));
	if (IS_ERR(minor))
		return PTR_ERR(minor);

	dev = minor->dev;

	atomic_fetch_inc(&dev->open_count);

	/* share address_space across all char-devs of a single device */
	filp->f_mapping = dev->anon_inode->i_mapping;

	retcode = drm_open_helper(filp, minor);
	if (retcode)
		goto err_undo;

	return 0;

err_undo:
	atomic_dec(&dev->open_count);
	accel_minor_release(minor);
	return retcode;
}
EXPORT_SYMBOL_GPL(accel_open);

static int accel_stub_open(struct inode *inode, struct file *filp)
{
	const struct file_operations *new_fops;
	struct drm_minor *minor;
	int err;

	minor = accel_minor_acquire(iminor(inode));
	if (IS_ERR(minor))
		return PTR_ERR(minor);

	new_fops = fops_get(minor->dev->driver->fops);
	if (!new_fops) {
		err = -ENODEV;
		goto out;
	}

	replace_fops(filp, new_fops);
	if (filp->f_op->open)
		err = filp->f_op->open(inode, filp);
	else
		err = 0;

out:
	accel_minor_release(minor);

	return err;
}

static const struct file_operations accel_stub_fops = {
	.owner = THIS_MODULE,
	.open = accel_stub_open,
	.llseek = noop_llseek,
};

void accel_core_exit(void)
{
	unregister_chrdev(ACCEL_MAJOR, "accel");
	debugfs_remove(accel_debugfs_root);
	accel_sysfs_destroy();
	idr_destroy(&accel_minors_idr);
}

int __init accel_core_init(void)
{
	int ret;

	idr_init(&accel_minors_idr);

	ret = accel_sysfs_init();
	if (ret < 0) {
		DRM_ERROR("Cannot create ACCEL class: %d\n", ret);
		goto error;
	}

	accel_debugfs_root = debugfs_create_dir("accel", NULL);

	ret = register_chrdev(ACCEL_MAJOR, "accel", &accel_stub_fops);
	if (ret < 0)
		DRM_ERROR("Cannot register ACCEL major: %d\n", ret);

error:
	/*
	 * Any cleanup due to errors will be done in drm_core_exit() that
	 * will call accel_core_exit()
	 */
	return ret;
}
Commit	Line	Data
8bf48897 OG	1	// SPDX-License-Identifier: GPL-2.0
	2
	3	/*
	4	* Copyright 2022 HabanaLabs, Ltd.
	5	* All Rights Reserved.
	6	*
	7	*/
	8
	9	#include <linux/debugfs.h>
	10	#include <linux/device.h>
2c204f3d	11	#include <linux/idr.h>
8bf48897 OG	12
8bf48897 OG	13	#include <drm/drm_accel.h>
2c204f3d OG	14	#include <drm/drm_debugfs.h>
	15	#include <drm/drm_drv.h>
	16	#include <drm/drm_file.h>
8bf48897 OG	17	#include <drm/drm_ioctl.h>
	18	#include <drm/drm_print.h>
	19
2c204f3d OG	20	static DEFINE_SPINLOCK(accel_minor_lock);
	21	static struct idr accel_minors_idr;
	22
8bf48897 OG	23	static struct dentry *accel_debugfs_root;
	24	static struct class *accel_class;
	25
2c204f3d OG	26	static struct device_type accel_sysfs_device_minor = {
	27	.name = "accel_minor"
	28	};
	29
dcde56bb	30	static char accel_devnode(const struct device dev, umode_t *mode)
8bf48897 OG	31	{
	32	return kasprintf(GFP_KERNEL, "accel/%s", dev_name(dev));
	33	}
	34
	35	static int accel_sysfs_init(void)
	36	{
	37	accel_class = class_create(THIS_MODULE, "accel");
	38	if (IS_ERR(accel_class))
	39	return PTR_ERR(accel_class);
	40
	41	accel_class->devnode = accel_devnode;
	42
	43	return 0;
	44	}
	45
	46	static void accel_sysfs_destroy(void)
	47	{
	48	if (IS_ERR_OR_NULL(accel_class))
	49	return;
	50	class_destroy(accel_class);
	51	accel_class = NULL;
	52	}
	53
2c204f3d OG	54	static int accel_name_info(struct seq_file m, void data)
	55	{
	56	struct drm_info_node node = (struct drm_info_node ) m->private;
	57	struct drm_minor *minor = node->minor;
	58	struct drm_device *dev = minor->dev;
	59	struct drm_master *master;
	60
	61	mutex_lock(&dev->master_mutex);
	62	master = dev->master;
	63	seq_printf(m, "%s", dev->driver->name);
	64	if (dev->dev)
	65	seq_printf(m, " dev=%s", dev_name(dev->dev));
	66	if (master && master->unique)
	67	seq_printf(m, " master=%s", master->unique);
	68	if (dev->unique)
	69	seq_printf(m, " unique=%s", dev->unique);
	70	seq_puts(m, "\n");
	71	mutex_unlock(&dev->master_mutex);
	72
	73	return 0;
	74	}
	75
	76	static const struct drm_info_list accel_debugfs_list[] = {
	77	{"name", accel_name_info, 0}
	78	};
	79	#define ACCEL_DEBUGFS_ENTRIES ARRAY_SIZE(accel_debugfs_list)
	80
	81	/**
	82	* accel_debugfs_init() - Initialize debugfs for accel minor
	83	* @minor: Pointer to the drm_minor instance.
	84	* @minor_id: The minor's id
	85	*
	86	* This function initializes the drm minor's debugfs members and creates
	87	* a root directory for the minor in debugfs. It also creates common files
	88	* for accelerators and calls the driver's debugfs init callback.
	89	*/
	90	void accel_debugfs_init(struct drm_minor *minor, int minor_id)
	91	{
	92	struct drm_device *dev = minor->dev;
	93	char name[64];
	94
	95	INIT_LIST_HEAD(&minor->debugfs_list);
	96	mutex_init(&minor->debugfs_lock);
	97	sprintf(name, "%d", minor_id);
	98	minor->debugfs_root = debugfs_create_dir(name, accel_debugfs_root);
	99
	100	drm_debugfs_create_files(accel_debugfs_list, ACCEL_DEBUGFS_ENTRIES,
	101	minor->debugfs_root, minor);
	102
	103	if (dev->driver->debugfs_init)
	104	dev->driver->debugfs_init(minor);
	105	}
	106
	107	/**
	108	* accel_set_device_instance_params() - Set some device parameters for accel device
	109	* @kdev: Pointer to the device instance.
	110	* @index: The minor's index
	111	*
	112	* This function creates the dev_t of the device using the accel major and
	113	* the device's minor number. In addition, it sets the class and type of the
	114	* device instance to the accel sysfs class and device type, respectively.
	115	*/
	116	void accel_set_device_instance_params(struct device *kdev, int index)
	117	{
118	kdev->devt = MKDEV(ACCEL_MAJOR, index);
119	kdev->class = accel_class;
120	kdev->type = &accel_sysfs_device_minor;
121	}
122
123	/**
124	* accel_minor_alloc() - Allocates a new accel minor
125	*
126	* This function access the accel minors idr and allocates from it
127	* a new id to represent a new accel minor
128	*
129	* Return: A new id on success or error code in case idr_alloc failed
130	*/
131	int accel_minor_alloc(void)
132	{
133	unsigned long flags;
134	int r;
135
136	spin_lock_irqsave(&accel_minor_lock, flags);
137	r = idr_alloc(&accel_minors_idr, NULL, 0, ACCEL_MAX_MINORS, GFP_NOWAIT);
138	spin_unlock_irqrestore(&accel_minor_lock, flags);
139
140	return r;
141	}
142
143	/**
144	* accel_minor_remove() - Remove an accel minor
145	* @index: The minor id to remove.
146	*
147	* This function access the accel minors idr and removes from
148	* it the member with the id that is passed to this function.
149	*/
150	void accel_minor_remove(int index)
151	{
152	unsigned long flags;
153
154	spin_lock_irqsave(&accel_minor_lock, flags);
155	idr_remove(&accel_minors_idr, index);
156	spin_unlock_irqrestore(&accel_minor_lock, flags);
157	}
158
159	/**
160	* accel_minor_replace() - Replace minor pointer in accel minors idr.
161	* @minor: Pointer to the new minor.
162	* @index: The minor id to replace.
163	*
164	* This function access the accel minors idr structure and replaces the pointer
165	* that is associated with an existing id. Because the minor pointer can be
166	* NULL, we need to explicitly pass the index.
167	*
168	* Return: 0 for success, negative value for error
169	*/
170	void accel_minor_replace(struct drm_minor *minor, int index)
171	{
172	unsigned long flags;
173
174	spin_lock_irqsave(&accel_minor_lock, flags);
175	idr_replace(&accel_minors_idr, minor, index);
176	spin_unlock_irqrestore(&accel_minor_lock, flags);
177	}
178
179	/*
180	* Looks up the given minor-ID and returns the respective DRM-minor object. The
181	* refence-count of the underlying device is increased so you must release this
182	* object with accel_minor_release().
183	*
184	* The object can be only a drm_minor that represents an accel device.
185	*
186	* As long as you hold this minor, it is guaranteed that the object and the
187	* minor->dev pointer will stay valid! However, the device may get unplugged and
188	* unregistered while you hold the minor.
189	*/
190	static struct drm_minor *accel_minor_acquire(unsigned int minor_id)
191	{
192	struct drm_minor *minor;
193	unsigned long flags;
194
195	spin_lock_irqsave(&accel_minor_lock, flags);
196	minor = idr_find(&accel_minors_idr, minor_id);
197	if (minor)
198	drm_dev_get(minor->dev);
199	spin_unlock_irqrestore(&accel_minor_lock, flags);
200
201	if (!minor) {
202	return ERR_PTR(-ENODEV);
203	} else if (drm_dev_is_unplugged(minor->dev)) {
204	drm_dev_put(minor->dev);
205	return ERR_PTR(-ENODEV);
206	}
207
208	return minor;
209	}
210
211	static void accel_minor_release(struct drm_minor *minor)
212	{
213	drm_dev_put(minor->dev);
214	}
215
216	/**
217	* accel_open - open method for ACCEL file
218	* @inode: device inode
219	* @filp: file pointer.
220	*
221	* This function must be used by drivers as their &file_operations.open method.
222	* It looks up the correct ACCEL device and instantiates all the per-file
223	* resources for it. It also calls the &drm_driver.open driver callback.
224	*
225	* Return: 0 on success or negative errno value on failure.
226	*/
227	int accel_open(struct inode inode, struct file filp)
228	{
229	struct drm_device *dev;
230	struct drm_minor *minor;
231	int retcode;
232
233	minor = accel_minor_acquire(iminor(inode));
234	if (IS_ERR(minor))
235	return PTR_ERR(minor);
236
237	dev = minor->dev;
238
239	atomic_fetch_inc(&dev->open_count);
240
241	/* share address_space across all char-devs of a single device */
242	filp->f_mapping = dev->anon_inode->i_mapping;
243
244	retcode = drm_open_helper(filp, minor);
245	if (retcode)
246	goto err_undo;
247
248	return 0;
249
250	err_undo:
251	atomic_dec(&dev->open_count);
252	accel_minor_release(minor);
253	return retcode;
254	}
255	EXPORT_SYMBOL_GPL(accel_open);
256
8bf48897 OG	257	static int accel_stub_open(struct inode inode, struct file filp)
8bf48897 OG	258	{
2c204f3d OG	259	const struct file_operations *new_fops;
	260	struct drm_minor *minor;
	261	int err;
	262
	263	minor = accel_minor_acquire(iminor(inode));
	264	if (IS_ERR(minor))
	265	return PTR_ERR(minor);
	266
	267	new_fops = fops_get(minor->dev->driver->fops);
	268	if (!new_fops) {
	269	err = -ENODEV;
	270	goto out;
	271	}
	272
	273	replace_fops(filp, new_fops);
	274	if (filp->f_op->open)
	275	err = filp->f_op->open(inode, filp);
	276	else
	277	err = 0;
	278
	279	out:
	280	accel_minor_release(minor);
	281
	282	return err;
8bf48897 OG	283	}
	284
	285	static const struct file_operations accel_stub_fops = {
	286	.owner = THIS_MODULE,
	287	.open = accel_stub_open,
	288	.llseek = noop_llseek,
	289	};
	290
	291	void accel_core_exit(void)
	292	{
	293	unregister_chrdev(ACCEL_MAJOR, "accel");
	294	debugfs_remove(accel_debugfs_root);
	295	accel_sysfs_destroy();
2c204f3d	296	idr_destroy(&accel_minors_idr);
8bf48897 OG	297	}
	298
	299	int __init accel_core_init(void)
	300	{
	301	int ret;
	302
2c204f3d OG	303	idr_init(&accel_minors_idr);
2c204f3d OG	304
8bf48897 OG	305	ret = accel_sysfs_init();
	306	if (ret < 0) {
	307	DRM_ERROR("Cannot create ACCEL class: %d\n", ret);
	308	goto error;
	309	}
	310
	311	accel_debugfs_root = debugfs_create_dir("accel", NULL);
	312
	313	ret = register_chrdev(ACCEL_MAJOR, "accel", &accel_stub_fops);
	314	if (ret < 0)
	315	DRM_ERROR("Cannot register ACCEL major: %d\n", ret);
	316
	317	error:
	318	/*
	319	* Any cleanup due to errors will be done in drm_core_exit() that
	320	* will call accel_core_exit()
	321	*/
	322	return ret;
	323	}