path: root/drivers/gpu/drm/drm_drv.c

/*
 * Created: Fri Jan 19 10:48:35 2001 by faith@acm.org
 *
 * Copyright 2001 VA Linux Systems, Inc., Sunnyvale, California.
 * All Rights Reserved.
 *
 * Author Rickard E. (Rik) Faith <faith@valinux.com>
 *
 * 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
 * PRECISION INSIGHT 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 <linux/debugfs.h>
#include <linux/fs.h>
#include <linux/module.h>
#include <linux/moduleparam.h>
#include <linux/mount.h>
#include <linux/pseudo_fs.h>
#include <linux/slab.h>
#include <linux/srcu.h>
#include <linux/xarray.h>

#include <drm/drm_accel.h>
#include <drm/drm_cache.h>
#include <drm/drm_client.h>
#include <drm/drm_color_mgmt.h>
#include <drm/drm_drv.h>
#include <drm/drm_file.h>
#include <drm/drm_managed.h>
#include <drm/drm_mode_object.h>
#include <drm/drm_panic.h>
#include <drm/drm_print.h>
#include <drm/drm_privacy_screen_machine.h>

#include "drm_crtc_internal.h"
#include "drm_internal.h"

MODULE_AUTHOR("Gareth Hughes, Leif Delgass, José Fonseca, Jon Smirl");
MODULE_DESCRIPTION("DRM shared core routines");
MODULE_LICENSE("GPL and additional rights");

DEFINE_XARRAY_ALLOC(drm_minors_xa);

/*
 * If the drm core fails to init for whatever reason,
 * we should prevent any drivers from registering with it.
 * It's best to check this at drm_dev_init(), as some drivers
 * prefer to embed struct drm_device into their own device
 * structure and call drm_dev_init() themselves.
 */
static bool drm_core_init_complete;

static struct dentry *drm_debugfs_root;

DEFINE_STATIC_SRCU(drm_unplug_srcu);

/*
 * DRM Minors
 * A DRM device can provide several char-dev interfaces on the DRM-Major. Each
 * of them is represented by a drm_minor object. Depending on the capabilities
 * of the device-driver, different interfaces are registered.
 *
 * Minors can be accessed via dev->$minor_name. This pointer is either
 * NULL or a valid drm_minor pointer and stays valid as long as the device is
 * valid. This means, DRM minors have the same life-time as the underlying
 * device. However, this doesn't mean that the minor is active. Minors are
 * registered and unregistered dynamically according to device-state.
 */

static struct xarray *drm_minor_get_xa(enum drm_minor_type type)
{
	if (type == DRM_MINOR_PRIMARY || type == DRM_MINOR_RENDER)
		return &drm_minors_xa;
#if IS_ENABLED(CONFIG_DRM_ACCEL)
	else if (type == DRM_MINOR_ACCEL)
		return &accel_minors_xa;
#endif
	else
		return ERR_PTR(-EOPNOTSUPP);
}

static struct drm_minor **drm_minor_get_slot(struct drm_device *dev,
					     enum drm_minor_type type)
{
	switch (type) {
	case DRM_MINOR_PRIMARY:
		return &dev->primary;
	case DRM_MINOR_RENDER:
		return &dev->render;
	case DRM_MINOR_ACCEL:
		return &dev->accel;
	default:
		BUG();
	}
}

static void drm_minor_alloc_release(struct drm_device *dev, void *data)
{
	struct drm_minor *minor = data;

	WARN_ON(dev != minor->dev);

	put_device(minor->kdev);

	xa_erase(drm_minor_get_xa(minor->type), minor->index);
}

/*
 * DRM used to support 64 devices, for backwards compatibility we need to maintain the
 * minor allocation scheme where minors 0-63 are primary nodes, 64-127 are control nodes,
 * and 128-191 are render nodes.
 * After reaching the limit, we're allocating minors dynamically - first-come, first-serve.
 * Accel nodes are using a distinct major, so the minors are allocated in continuous 0-MAX
 * range.
 */
#define DRM_MINOR_LIMIT(t) ({ \
	typeof(t) _t = (t); \
	_t == DRM_MINOR_ACCEL ? XA_LIMIT(0, ACCEL_MAX_MINORS) : XA_LIMIT(64 * _t, 64 * _t + 63); \
})
#define DRM_EXTENDED_MINOR_LIMIT XA_LIMIT(192, (1 << MINORBITS) - 1)

static int drm_minor_alloc(struct drm_device *dev, enum drm_minor_type type)
{
	struct drm_minor *minor;
	int r;

	minor = drmm_kzalloc(dev, sizeof(*minor), GFP_KERNEL);
	if (!minor)
		return -ENOMEM;

	minor->type = type;
	minor->dev = dev;

	r = xa_alloc(drm_minor_get_xa(type), &minor->index,
		     NULL, DRM_MINOR_LIMIT(type), GFP_KERNEL);
	if (r == -EBUSY && (type == DRM_MINOR_PRIMARY || type == DRM_MINOR_RENDER))
		r = xa_alloc(&drm_minors_xa, &minor->index,
			     NULL, DRM_EXTENDED_MINOR_LIMIT, GFP_KERNEL);
	if (r < 0)
		return r;

	r = drmm_add_action_or_reset(dev, drm_minor_alloc_release, minor);
	if (r)
		return r;

	minor->kdev = drm_sysfs_minor_alloc(minor);
	if (IS_ERR(minor->kdev))
		return PTR_ERR(minor->kdev);

	*drm_minor_get_slot(dev, type) = minor;
	return 0;
}

static int drm_minor_register(struct drm_device *dev, enum drm_minor_type type)
{
	struct drm_minor *minor;
	void *entry;
	int ret;

	DRM_DEBUG("\n");

	minor = *drm_minor_get_slot(dev, type);
	if (!minor)
		return 0;

	if (minor->type != DRM_MINOR_ACCEL) {
		ret = drm_debugfs_register(minor, minor->index,
					   drm_debugfs_root);
		if (ret</