drm: move module initialization to drm_stub.c

Most of the new DRM management functions are nowadays in drm_stub.c. By
moving the core module initialization to drm_stub.c we can make several
global variables static and keep the stub-open helper local.

The core files now look like this:
  drm_stub.c: Core management
   drm_drv.c: Ioctl dispatcher
 drm_ioctl.c: Actual ioctl backends
  drm_fops.c: Char-dev file-operations

A follow-up patch will move what is left from drm_drv.c into drm_ioctl.c.
Acked-by: NDaniel Vetter <daniel.vetter@ffwll.ch>
Reviewed-by: NAlex Deucher <alexander.deucher@amd.com>
Signed-off-by: NDavid Herrmann <dh.herrmann@gmail.com>

drivers/gpu/drm/drm_drv.c

@@ -171,65 +171,6 @@ static const struct drm_ioctl_desc drm_ioctls[] = {
 
 #define DRM_CORE_IOCTL_COUNT	ARRAY_SIZE( drm_ioctls )
 
-/** File operations structure */
-static const struct file_operations drm_stub_fops = {
-	.owner = THIS_MODULE,
-	.open = drm_stub_open,
-	.llseek = noop_llseek,
-};
-
-static int __init drm_core_init(void)
-{
-	int ret = -ENOMEM;
-
-	drm_global_init();
-	drm_connector_ida_init();
-	idr_init(&drm_minors_idr);
-
-	if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
-		goto err_p1;
-
-	drm_class = drm_sysfs_create(THIS_MODULE, "drm");
-	if (IS_ERR(drm_class)) {
-		printk(KERN_ERR "DRM: Error creating drm class.\n");
-		ret = PTR_ERR(drm_class);
-		goto err_p2;
-	}
-
-	drm_debugfs_root = debugfs_create_dir("dri", NULL);
-	if (!drm_debugfs_root) {
-		DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
-		ret = -1;
-		goto err_p3;
-	}
-
-	DRM_INFO("Initialized %s %d.%d.%d %s\n",
-		 CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
-	return 0;
-err_p3:
-	drm_sysfs_destroy();
-err_p2:
-	unregister_chrdev(DRM_MAJOR, "drm");
-
-	idr_destroy(&drm_minors_idr);
-err_p1:
-	return ret;
-}
-
-static void __exit drm_core_exit(void)
-{
-	debugfs_remove(drm_debugfs_root);
-	drm_sysfs_destroy();
-
-	unregister_chrdev(DRM_MAJOR, "drm");
-
-	drm_connector_ida_destroy();
-	idr_destroy(&drm_minors_idr);
-}
-
-module_init(drm_core_init);
-module_exit(drm_core_exit);
-
 /**
  * Copy and IOCTL return string to user space
  */

drivers/gpu/drm/drm_fops.c

@@ -111,45 +111,6 @@ int drm_open(struct inode *inode, struct file *filp)
 }
 EXPORT_SYMBOL(drm_open);
 
-/**
- * File \c open operation.
- *
- * \param inode device inode.
- * \param filp file pointer.
- *
- * Puts the dev->fops corresponding to the device minor number into
- * \p filp, call the \c open method, and restore the file operations.
- */
-int drm_stub_open(struct inode *inode, struct file *filp)
-{
-	struct drm_device *dev;
-	struct drm_minor *minor;
-	int err = -ENODEV;
-	const struct file_operations *new_fops;
-
-	DRM_DEBUG("\n");
-
-	mutex_lock(&drm_global_mutex);
-	minor = drm_minor_acquire(iminor(inode));
-	if (IS_ERR(minor))
-		goto out_unlock;
-
-	dev = minor->dev;
-	new_fops = fops_get(dev->driver->fops);
-	if (!new_fops)
-		goto out_release;
-
-	replace_fops(filp, new_fops);
-	if (filp->f_op->open)
-		err = filp->f_op->open(inode, filp);
-
-out_release:
-	drm_minor_release(minor);
-out_unlock:
-	mutex_unlock(&drm_global_mutex);
-	return err;
-}
-
 /**
  * Check whether DRI will run on this CPU.
  *

drivers/gpu/drm/drm_stub.c

@@ -26,6 +26,7 @@
  * DEALINGS IN THE SOFTWARE.
  */
 
+#include <linux/debugfs.h>
 #include <linux/fs.h>
 #include <linux/module.h>
 #include <linux/moduleparam.h>
@@ -61,10 +62,10 @@ module_param_named(timestamp_precision_usec, drm_timestamp_precision, int, 0600)
 module_param_named(timestamp_monotonic, drm_timestamp_monotonic, int, 0600);
 
 static DEFINE_SPINLOCK(drm_minor_lock);
-struct idr drm_minors_idr;
+static struct idr drm_minors_idr;
 
 struct class *drm_class;
-struct dentry *drm_debugfs_root;
+static struct dentry *drm_debugfs_root;
 
 int drm_err(const char *func, const char *format, ...)
 {
@@ -787,3 +788,115 @@ int drm_dev_set_unique(struct drm_device *dev, const char *fmt, ...)
 	return dev->unique ? 0 : -ENOMEM;
 }
 EXPORT_SYMBOL(drm_dev_set_unique);
+
+/*
+ * DRM Core
+ * The DRM core module initializes all global DRM objects and makes them
+ * available to drivers. Once setup, drivers can probe their respective
+ * devices.
+ * Currently, core management includes:
+ *  - The "DRM-Global" key/value database
+ *  - Global ID management for connectors
+ *  - DRM major number allocation
+ *  - DRM minor management
+ *  - DRM sysfs class
+ *  - DRM debugfs root
+ *
+ * Furthermore, the DRM core provides dynamic char-dev lookups. For each
+ * interface registered on a DRM device, you can request minor numbers from DRM
+ * core. DRM core takes care of major-number management and char-dev
+ * registration. A stub ->open() callback forwards any open() requests to the
+ * registered minor.
+ */
+
+static int drm_stub_open(struct inode *inode, struct file *filp)
+{
+	const struct file_operations *new_fops;
+	struct drm_minor *minor;
+	int err;
+
+	DRM_DEBUG("\n");
+
+	mutex_lock(&drm_global_mutex);
+	minor = drm_minor_acquire(iminor(inode));
+	if (IS_ERR(minor)) {
+		err = PTR_ERR(minor);
+		goto out_unlock;
+	}
+
+	new_fops = fops_get(minor->dev->driver->fops);
+	if (!new_fops) {
+		err = -ENODEV;
+		goto out_release;
+	}
+
+	replace_fops(filp, new_fops);
+	if (filp->f_op->open)
+		err = filp->f_op->open(inode, filp);
+	else
+		err = 0;
+
+out_release:
+	drm_minor_release(minor);
+out_unlock:
+	mutex_unlock(&drm_global_mutex);
+	return err;
+}
+
+static const struct file_operations drm_stub_fops = {
+	.owner = THIS_MODULE,
+	.open = drm_stub_open,
+	.llseek = noop_llseek,
+};
+
+static int __init drm_core_init(void)
+{
+	int ret = -ENOMEM;
+
+	drm_global_init();
+	drm_connector_ida_init();
+	idr_init(&drm_minors_idr);
+
+	if (register_chrdev(DRM_MAJOR, "drm", &drm_stub_fops))
+		goto err_p1;
+
+	drm_class = drm_sysfs_create(THIS_MODULE, "drm");
+	if (IS_ERR(drm_class)) {
+		printk(KERN_ERR "DRM: Error creating drm class.\n");
+		ret = PTR_ERR(drm_class);
+		goto err_p2;
+	}
+
+	drm_debugfs_root = debugfs_create_dir("dri", NULL);
+	if (!drm_debugfs_root) {
+		DRM_ERROR("Cannot create /sys/kernel/debug/dri\n");
+		ret = -1;
+		goto err_p3;
+	}
+
+	DRM_INFO("Initialized %s %d.%d.%d %s\n",
+		 CORE_NAME, CORE_MAJOR, CORE_MINOR, CORE_PATCHLEVEL, CORE_DATE);
+	return 0;
+err_p3:
+	drm_sysfs_destroy();
+err_p2:
+	unregister_chrdev(DRM_MAJOR, "drm");
+
+	idr_destroy(&drm_minors_idr);
+err_p1:
+	return ret;
+}
+
+static void __exit drm_core_exit(void)
+{
+	debugfs_remove(drm_debugfs_root);
+	drm_sysfs_destroy();
+
+	unregister_chrdev(DRM_MAJOR, "drm");
+
+	drm_connector_ida_destroy();
+	idr_destroy(&drm_minors_idr);
+}
+
+module_init(drm_core_init);
+module_exit(drm_core_exit);

include/drm/drmP.h

@@ -1199,7 +1199,6 @@ extern bool drm_ioctl_flags(unsigned int nr, unsigned int *flags);
 				/* Device support (drm_fops.h) */
 extern struct mutex drm_global_mutex;
 extern int drm_open(struct inode *inode, struct file *filp);
-extern int drm_stub_open(struct inode *inode, struct file *filp);
 extern ssize_t drm_read(struct file *filp, char __user *buffer,
 			size_t count, loff_t *offset);
 extern int drm_release(struct inode *inode, struct file *filp);
@@ -1386,9 +1385,6 @@ extern unsigned int drm_timestamp_precision;
 extern unsigned int drm_timestamp_monotonic;
 
 extern struct class *drm_class;
-extern struct dentry *drm_debugfs_root;
-
-extern struct idr drm_minors_idr;
 
 extern struct drm_local_map *drm_getsarea(struct drm_device *dev);