#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(struct device *dev, umode_t *mode)
{
return kasprintf(GFP_KERNEL, "accel/%s", dev_name(dev));
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)
{
- return -EOPNOTSUPP;
+ 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 = {
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);
#ifndef DRM_ACCEL_H_
#define DRM_ACCEL_H_
+#include <drm/drm_file.h>
+
#define ACCEL_MAJOR 261
+#define ACCEL_MAX_MINORS 256
+
+/**
+ * DRM_ACCEL_FOPS - Default drm accelerators file operations
+ *
+ * This macro provides a shorthand for setting the accelerator file ops in the
+ * &file_operations structure. If all you need are the default ops, use
+ * DEFINE_DRM_ACCEL_FOPS instead.
+ */
+#define DRM_ACCEL_FOPS \
+ .open = accel_open,\
+ .release = drm_release,\
+ .unlocked_ioctl = drm_ioctl,\
+ .compat_ioctl = drm_compat_ioctl,\
+ .poll = drm_poll,\
+ .read = drm_read,\
+ .llseek = noop_llseek
+
+/**
+ * DEFINE_DRM_ACCEL_FOPS() - macro to generate file operations for accelerators drivers
+ * @name: name for the generated structure
+ *
+ * This macro autogenerates a suitable &struct file_operations for accelerators based
+ * drivers, which can be assigned to &drm_driver.fops. Note that this structure
+ * cannot be shared between drivers, because it contains a reference to the
+ * current module using THIS_MODULE.
+ *
+ * Note that the declaration is already marked as static - if you need a
+ * non-static version of this you're probably doing it wrong and will break the
+ * THIS_MODULE reference by accident.
+ */
+#define DEFINE_DRM_ACCEL_FOPS(name) \
+ static const struct file_operations name = {\
+ .owner = THIS_MODULE,\
+ DRM_ACCEL_FOPS,\
+ }
#if IS_ENABLED(CONFIG_DRM_ACCEL)
void accel_core_exit(void);
int accel_core_init(void);
+void accel_minor_remove(int index);
+int accel_minor_alloc(void);
+void accel_minor_replace(struct drm_minor *minor, int index);
+void accel_set_device_instance_params(struct device *kdev, int index);
+int accel_open(struct inode *inode, struct file *filp);
+void accel_debugfs_init(struct drm_minor *minor, int minor_id);
#else
return 0;
}
+static inline void accel_minor_remove(int index)
+{
+}
+
+static inline int accel_minor_alloc(void)
+{
+ return -EOPNOTSUPP;
+}
+
+static inline void accel_minor_replace(struct drm_minor *minor, int index)
+{
+}
+
+static inline void accel_set_device_instance_params(struct device *kdev, int index)
+{
+}
+
+static inline void accel_debugfs_init(struct drm_minor *minor, int minor_id)
+{
+}
+
#endif /* IS_ENABLED(CONFIG_DRM_ACCEL) */
#endif /* DRM_ACCEL_H_ */