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![Linus Torvalds](/assets/img/avatar_default.png)
This was a mismerge of a semantic conflict in my merge of the driver core updates, where commitff62b8e658
("driver core: make struct class.devnode() take a const *") changed the devnode function pointer type. In the meantime, the drm tree I merged earlier had introduced a new use of that in commit8bf4889762
("drivers/accel: define kconfig and register a new major"). And of course this happens when I'm traveling with my laptop, and thus didn't do a full allmodconfig build between every pull and before pushing my work out. So I only noticed later as I was doing my full build. Brown-paper-bag-by: Linus Torvalds <torvalds@linux-foundation.org> Fixes:71a7507afb
Merge tag 'driver-core-6.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
323 lines
7.9 KiB
C
323 lines
7.9 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* Copyright 2022 HabanaLabs, Ltd.
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* All Rights Reserved.
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*
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*/
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#include <linux/debugfs.h>
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#include <linux/device.h>
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#include <linux/idr.h>
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#include <drm/drm_accel.h>
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#include <drm/drm_debugfs.h>
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#include <drm/drm_drv.h>
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#include <drm/drm_file.h>
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#include <drm/drm_ioctl.h>
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#include <drm/drm_print.h>
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static DEFINE_SPINLOCK(accel_minor_lock);
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static struct idr accel_minors_idr;
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static struct dentry *accel_debugfs_root;
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static struct class *accel_class;
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static struct device_type accel_sysfs_device_minor = {
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.name = "accel_minor"
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};
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static char *accel_devnode(const struct device *dev, umode_t *mode)
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{
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return kasprintf(GFP_KERNEL, "accel/%s", dev_name(dev));
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}
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static int accel_sysfs_init(void)
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{
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accel_class = class_create(THIS_MODULE, "accel");
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if (IS_ERR(accel_class))
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return PTR_ERR(accel_class);
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accel_class->devnode = accel_devnode;
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return 0;
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}
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static void accel_sysfs_destroy(void)
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{
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if (IS_ERR_OR_NULL(accel_class))
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return;
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class_destroy(accel_class);
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accel_class = NULL;
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}
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static int accel_name_info(struct seq_file *m, void *data)
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{
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struct drm_info_node *node = (struct drm_info_node *) m->private;
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struct drm_minor *minor = node->minor;
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struct drm_device *dev = minor->dev;
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struct drm_master *master;
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mutex_lock(&dev->master_mutex);
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master = dev->master;
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seq_printf(m, "%s", dev->driver->name);
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if (dev->dev)
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seq_printf(m, " dev=%s", dev_name(dev->dev));
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if (master && master->unique)
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seq_printf(m, " master=%s", master->unique);
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if (dev->unique)
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seq_printf(m, " unique=%s", dev->unique);
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seq_puts(m, "\n");
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mutex_unlock(&dev->master_mutex);
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return 0;
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}
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static const struct drm_info_list accel_debugfs_list[] = {
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{"name", accel_name_info, 0}
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};
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#define ACCEL_DEBUGFS_ENTRIES ARRAY_SIZE(accel_debugfs_list)
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/**
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* accel_debugfs_init() - Initialize debugfs for accel minor
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* @minor: Pointer to the drm_minor instance.
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* @minor_id: The minor's id
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*
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* This function initializes the drm minor's debugfs members and creates
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* a root directory for the minor in debugfs. It also creates common files
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* for accelerators and calls the driver's debugfs init callback.
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*/
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void accel_debugfs_init(struct drm_minor *minor, int minor_id)
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{
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struct drm_device *dev = minor->dev;
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char name[64];
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INIT_LIST_HEAD(&minor->debugfs_list);
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mutex_init(&minor->debugfs_lock);
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sprintf(name, "%d", minor_id);
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minor->debugfs_root = debugfs_create_dir(name, accel_debugfs_root);
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drm_debugfs_create_files(accel_debugfs_list, ACCEL_DEBUGFS_ENTRIES,
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minor->debugfs_root, minor);
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if (dev->driver->debugfs_init)
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dev->driver->debugfs_init(minor);
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}
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/**
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* accel_set_device_instance_params() - Set some device parameters for accel device
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* @kdev: Pointer to the device instance.
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* @index: The minor's index
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*
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* This function creates the dev_t of the device using the accel major and
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* the device's minor number. In addition, it sets the class and type of the
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* device instance to the accel sysfs class and device type, respectively.
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*/
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void accel_set_device_instance_params(struct device *kdev, int index)
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{
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kdev->devt = MKDEV(ACCEL_MAJOR, index);
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kdev->class = accel_class;
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kdev->type = &accel_sysfs_device_minor;
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}
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/**
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* accel_minor_alloc() - Allocates a new accel minor
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*
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* This function access the accel minors idr and allocates from it
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* a new id to represent a new accel minor
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*
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* Return: A new id on success or error code in case idr_alloc failed
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*/
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int accel_minor_alloc(void)
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{
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unsigned long flags;
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int r;
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spin_lock_irqsave(&accel_minor_lock, flags);
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r = idr_alloc(&accel_minors_idr, NULL, 0, ACCEL_MAX_MINORS, GFP_NOWAIT);
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spin_unlock_irqrestore(&accel_minor_lock, flags);
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return r;
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}
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/**
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* accel_minor_remove() - Remove an accel minor
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* @index: The minor id to remove.
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*
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* This function access the accel minors idr and removes from
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* it the member with the id that is passed to this function.
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*/
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void accel_minor_remove(int index)
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{
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unsigned long flags;
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spin_lock_irqsave(&accel_minor_lock, flags);
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idr_remove(&accel_minors_idr, index);
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spin_unlock_irqrestore(&accel_minor_lock, flags);
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}
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/**
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* accel_minor_replace() - Replace minor pointer in accel minors idr.
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* @minor: Pointer to the new minor.
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* @index: The minor id to replace.
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*
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* This function access the accel minors idr structure and replaces the pointer
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* that is associated with an existing id. Because the minor pointer can be
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* NULL, we need to explicitly pass the index.
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*
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* Return: 0 for success, negative value for error
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*/
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void accel_minor_replace(struct drm_minor *minor, int index)
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{
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unsigned long flags;
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spin_lock_irqsave(&accel_minor_lock, flags);
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idr_replace(&accel_minors_idr, minor, index);
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spin_unlock_irqrestore(&accel_minor_lock, flags);
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}
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/*
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* Looks up the given minor-ID and returns the respective DRM-minor object. The
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* refence-count of the underlying device is increased so you must release this
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* object with accel_minor_release().
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*
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* The object can be only a drm_minor that represents an accel device.
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*
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* As long as you hold this minor, it is guaranteed that the object and the
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* minor->dev pointer will stay valid! However, the device may get unplugged and
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* unregistered while you hold the minor.
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*/
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static struct drm_minor *accel_minor_acquire(unsigned int minor_id)
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{
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struct drm_minor *minor;
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unsigned long flags;
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spin_lock_irqsave(&accel_minor_lock, flags);
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minor = idr_find(&accel_minors_idr, minor_id);
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if (minor)
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drm_dev_get(minor->dev);
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spin_unlock_irqrestore(&accel_minor_lock, flags);
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if (!minor) {
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return ERR_PTR(-ENODEV);
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} else if (drm_dev_is_unplugged(minor->dev)) {
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drm_dev_put(minor->dev);
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return ERR_PTR(-ENODEV);
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}
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return minor;
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}
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static void accel_minor_release(struct drm_minor *minor)
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{
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drm_dev_put(minor->dev);
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}
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/**
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* accel_open - open method for ACCEL file
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* @inode: device inode
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* @filp: file pointer.
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*
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* This function must be used by drivers as their &file_operations.open method.
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* It looks up the correct ACCEL device and instantiates all the per-file
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* resources for it. It also calls the &drm_driver.open driver callback.
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*
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* Return: 0 on success or negative errno value on failure.
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*/
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int accel_open(struct inode *inode, struct file *filp)
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{
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struct drm_device *dev;
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struct drm_minor *minor;
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int retcode;
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minor = accel_minor_acquire(iminor(inode));
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if (IS_ERR(minor))
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return PTR_ERR(minor);
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dev = minor->dev;
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atomic_fetch_inc(&dev->open_count);
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/* share address_space across all char-devs of a single device */
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filp->f_mapping = dev->anon_inode->i_mapping;
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retcode = drm_open_helper(filp, minor);
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if (retcode)
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goto err_undo;
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return 0;
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err_undo:
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atomic_dec(&dev->open_count);
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accel_minor_release(minor);
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return retcode;
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}
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EXPORT_SYMBOL_GPL(accel_open);
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static int accel_stub_open(struct inode *inode, struct file *filp)
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{
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const struct file_operations *new_fops;
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struct drm_minor *minor;
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int err;
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minor = accel_minor_acquire(iminor(inode));
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if (IS_ERR(minor))
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return PTR_ERR(minor);
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new_fops = fops_get(minor->dev->driver->fops);
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if (!new_fops) {
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err = -ENODEV;
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goto out;
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}
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replace_fops(filp, new_fops);
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if (filp->f_op->open)
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err = filp->f_op->open(inode, filp);
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else
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err = 0;
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out:
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accel_minor_release(minor);
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return err;
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}
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static const struct file_operations accel_stub_fops = {
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.owner = THIS_MODULE,
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.open = accel_stub_open,
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.llseek = noop_llseek,
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};
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void accel_core_exit(void)
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{
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unregister_chrdev(ACCEL_MAJOR, "accel");
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debugfs_remove(accel_debugfs_root);
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accel_sysfs_destroy();
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idr_destroy(&accel_minors_idr);
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}
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int __init accel_core_init(void)
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{
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int ret;
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idr_init(&accel_minors_idr);
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ret = accel_sysfs_init();
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if (ret < 0) {
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DRM_ERROR("Cannot create ACCEL class: %d\n", ret);
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goto error;
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}
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accel_debugfs_root = debugfs_create_dir("accel", NULL);
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ret = register_chrdev(ACCEL_MAJOR, "accel", &accel_stub_fops);
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if (ret < 0)
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DRM_ERROR("Cannot register ACCEL major: %d\n", ret);
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error:
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/*
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* Any cleanup due to errors will be done in drm_core_exit() that
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* will call accel_core_exit()
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*/
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return ret;
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}
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