diff mbox series

[v3,36/38] fbdev/core: Move file-I/O code into separate file

Message ID 20230613110953.24176-37-tzimmermann@suse.de (mailing list archive)
State New, archived
Headers show
Series fbdev: Make userspace interfaces optional | expand

Commit Message

Thomas Zimmermann June 13, 2023, 11:07 a.m. UTC
Move fbdev's file-I/O code into a separate file and contain it in
init and cleanup helpers. No functional changes.

v3:
	* add missing file fb_chrdev.c
v2:
	* rename source file (Sam)
	* include <linux/compat.h> (Javier, kernel test robot)

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
---
 drivers/video/fbdev/core/Makefile      |   1 +
 drivers/video/fbdev/core/fb_chrdev.c   | 485 +++++++++++++++++++++++++
 drivers/video/fbdev/core/fb_internal.h |   6 +
 drivers/video/fbdev/core/fbmem.c       | 479 +-----------------------
 4 files changed, 498 insertions(+), 473 deletions(-)
 create mode 100644 drivers/video/fbdev/core/fb_chrdev.c
diff mbox series

Patch

diff --git a/drivers/video/fbdev/core/Makefile b/drivers/video/fbdev/core/Makefile
index 665320160f70a..eea5938f74238 100644
--- a/drivers/video/fbdev/core/Makefile
+++ b/drivers/video/fbdev/core/Makefile
@@ -2,6 +2,7 @@ 
 obj-$(CONFIG_FB_NOTIFY)           += fb_notify.o
 obj-$(CONFIG_FB)                  += fb.o
 fb-y                              := fb_backlight.o \
+                                     fb_chrdev.o \
                                      fb_info.o \
                                      fb_procfs.o \
                                      fbmem.o fbmon.o fbcmap.o fbsysfs.o \
diff --git a/drivers/video/fbdev/core/fb_chrdev.c b/drivers/video/fbdev/core/fb_chrdev.c
new file mode 100644
index 0000000000000..eadb81f53a821
--- /dev/null
+++ b/drivers/video/fbdev/core/fb_chrdev.c
@@ -0,0 +1,485 @@ 
+// SPDX-License-Identifier: GPL-2.0
+
+#include <linux/compat.h>
+#include <linux/console.h>
+#include <linux/fb.h>
+#include <linux/fbcon.h>
+#include <linux/major.h>
+
+#include "fb_internal.h"
+
+/*
+ * We hold a reference to the fb_info in file->private_data,
+ * but if the current registered fb has changed, we don't
+ * actually want to use it.
+ *
+ * So look up the fb_info using the inode minor number,
+ * and just verify it against the reference we have.
+ */
+static struct fb_info *file_fb_info(struct file *file)
+{
+	struct inode *inode = file_inode(file);
+	int fbidx = iminor(inode);
+	struct fb_info *info = registered_fb[fbidx];
+
+	if (info != file->private_data)
+		info = NULL;
+	return info;
+}
+
+static ssize_t fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
+{
+	struct fb_info *info = file_fb_info(file);
+
+	if (!info)
+		return -ENODEV;
+
+	if (info->state != FBINFO_STATE_RUNNING)
+		return -EPERM;
+
+	if (info->fbops->fb_read)
+		return info->fbops->fb_read(info, buf, count, ppos);
+
+	return fb_io_read(info, buf, count, ppos);
+}
+
+static ssize_t fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
+{
+	struct fb_info *info = file_fb_info(file);
+
+	if (!info)
+		return -ENODEV;
+
+	if (info->state != FBINFO_STATE_RUNNING)
+		return -EPERM;
+
+	if (info->fbops->fb_write)
+		return info->fbops->fb_write(info, buf, count, ppos);
+
+	return fb_io_write(info, buf, count, ppos);
+}
+
+static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
+			unsigned long arg)
+{
+	const struct fb_ops *fb;
+	struct fb_var_screeninfo var;
+	struct fb_fix_screeninfo fix;
+	struct fb_cmap cmap_from;
+	struct fb_cmap_user cmap;
+	void __user *argp = (void __user *)arg;
+	long ret = 0;
+
+	switch (cmd) {
+	case FBIOGET_VSCREENINFO:
+		lock_fb_info(info);
+		var = info->var;
+		unlock_fb_info(info);
+
+		ret = copy_to_user(argp, &var, sizeof(var)) ? -EFAULT : 0;
+		break;
+	case FBIOPUT_VSCREENINFO:
+		if (copy_from_user(&var, argp, sizeof(var)))
+			return -EFAULT;
+		/* only for kernel-internal use */
+		var.activate &= ~FB_ACTIVATE_KD_TEXT;
+		console_lock();
+		lock_fb_info(info);
+		ret = fbcon_modechange_possible(info, &var);
+		if (!ret)
+			ret = fb_set_var(info, &var);
+		if (!ret)
+			fbcon_update_vcs(info, var.activate & FB_ACTIVATE_ALL);
+		unlock_fb_info(info);
+		console_unlock();
+		if (!ret && copy_to_user(argp, &var, sizeof(var)))
+			ret = -EFAULT;
+		break;
+	case FBIOGET_FSCREENINFO:
+		lock_fb_info(info);
+		memcpy(&fix, &info->fix, sizeof(fix));
+		if (info->flags & FBINFO_HIDE_SMEM_START)
+			fix.smem_start = 0;
+		unlock_fb_info(info);
+
+		ret = copy_to_user(argp, &fix, sizeof(fix)) ? -EFAULT : 0;
+		break;
+	case FBIOPUTCMAP:
+		if (copy_from_user(&cmap, argp, sizeof(cmap)))
+			return -EFAULT;
+		ret = fb_set_user_cmap(&cmap, info);
+		break;
+	case FBIOGETCMAP:
+		if (copy_from_user(&cmap, argp, sizeof(cmap)))
+			return -EFAULT;
+		lock_fb_info(info);
+		cmap_from = info->cmap;
+		unlock_fb_info(info);
+		ret = fb_cmap_to_user(&cmap_from, &cmap);
+		break;
+	case FBIOPAN_DISPLAY:
+		if (copy_from_user(&var, argp, sizeof(var)))
+			return -EFAULT;
+		console_lock();
+		lock_fb_info(info);
+		ret = fb_pan_display(info, &var);
+		unlock_fb_info(info);
+		console_unlock();
+		if (ret == 0 && copy_to_user(argp, &var, sizeof(var)))
+			return -EFAULT;
+		break;
+	case FBIO_CURSOR:
+		ret = -EINVAL;
+		break;
+	case FBIOGET_CON2FBMAP:
+		ret = fbcon_get_con2fb_map_ioctl(argp);
+		break;
+	case FBIOPUT_CON2FBMAP:
+		ret = fbcon_set_con2fb_map_ioctl(argp);
+		break;
+	case FBIOBLANK:
+		if (arg > FB_BLANK_POWERDOWN)
+			return -EINVAL;
+		console_lock();
+		lock_fb_info(info);
+		ret = fb_blank(info, arg);
+		/* might again call into fb_blank */
+		fbcon_fb_blanked(info, arg);
+		unlock_fb_info(info);
+		console_unlock();
+		break;
+	default:
+		lock_fb_info(info);
+		fb = info->fbops;
+		if (fb->fb_ioctl)
+			ret = fb->fb_ioctl(info, cmd, arg);
+		else
+			ret = -ENOTTY;
+		unlock_fb_info(info);
+	}
+	return ret;
+}
+
+static long fb_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+	struct fb_info *info = file_fb_info(file);
+
+	if (!info)
+		return -ENODEV;
+	return do_fb_ioctl(info, cmd, arg);
+}
+
+#ifdef CONFIG_COMPAT
+struct fb_fix_screeninfo32 {
+	char			id[16];
+	compat_caddr_t		smem_start;
+	u32			smem_len;
+	u32			type;
+	u32			type_aux;
+	u32			visual;
+	u16			xpanstep;
+	u16			ypanstep;
+	u16			ywrapstep;
+	u32			line_length;
+	compat_caddr_t		mmio_start;
+	u32			mmio_len;
+	u32			accel;
+	u16			reserved[3];
+};
+
+struct fb_cmap32 {
+	u32			start;
+	u32			len;
+	compat_caddr_t	red;
+	compat_caddr_t	green;
+	compat_caddr_t	blue;
+	compat_caddr_t	transp;
+};
+
+static int fb_getput_cmap(struct fb_info *info, unsigned int cmd,
+			  unsigned long arg)
+{
+	struct fb_cmap32 cmap32;
+	struct fb_cmap cmap_from;
+	struct fb_cmap_user cmap;
+
+	if (copy_from_user(&cmap32, compat_ptr(arg), sizeof(cmap32)))
+		return -EFAULT;
+
+	cmap = (struct fb_cmap_user) {
+		.start	= cmap32.start,
+		.len	= cmap32.len,
+		.red	= compat_ptr(cmap32.red),
+		.green	= compat_ptr(cmap32.green),
+		.blue	= compat_ptr(cmap32.blue),
+		.transp	= compat_ptr(cmap32.transp),
+	};
+
+	if (cmd == FBIOPUTCMAP)
+		return fb_set_user_cmap(&cmap, info);
+
+	lock_fb_info(info);
+	cmap_from = info->cmap;
+	unlock_fb_info(info);
+
+	return fb_cmap_to_user(&cmap_from, &cmap);
+}
+
+static int do_fscreeninfo_to_user(struct fb_fix_screeninfo *fix,
+				  struct fb_fix_screeninfo32 __user *fix32)
+{
+	__u32 data;
+	int err;
+
+	err = copy_to_user(&fix32->id, &fix->id, sizeof(fix32->id));
+
+	data = (__u32) (unsigned long) fix->smem_start;
+	err |= put_user(data, &fix32->smem_start);
+
+	err |= put_user(fix->smem_len, &fix32->smem_len);
+	err |= put_user(fix->type, &fix32->type);
+	err |= put_user(fix->type_aux, &fix32->type_aux);
+	err |= put_user(fix->visual, &fix32->visual);
+	err |= put_user(fix->xpanstep, &fix32->xpanstep);
+	err |= put_user(fix->ypanstep, &fix32->ypanstep);
+	err |= put_user(fix->ywrapstep, &fix32->ywrapstep);
+	err |= put_user(fix->line_length, &fix32->line_length);
+
+	data = (__u32) (unsigned long) fix->mmio_start;
+	err |= put_user(data, &fix32->mmio_start);
+
+	err |= put_user(fix->mmio_len, &fix32->mmio_len);
+	err |= put_user(fix->accel, &fix32->accel);
+	err |= copy_to_user(fix32->reserved, fix->reserved,
+			    sizeof(fix->reserved));
+
+	if (err)
+		return -EFAULT;
+	return 0;
+}
+
+static int fb_get_fscreeninfo(struct fb_info *info, unsigned int cmd,
+			      unsigned long arg)
+{
+	struct fb_fix_screeninfo fix;
+
+	lock_fb_info(info);
+	fix = info->fix;
+	if (info->flags & FBINFO_HIDE_SMEM_START)
+		fix.smem_start = 0;
+	unlock_fb_info(info);
+	return do_fscreeninfo_to_user(&fix, compat_ptr(arg));
+}
+
+static long fb_compat_ioctl(struct file *file, unsigned int cmd,
+			    unsigned long arg)
+{
+	struct fb_info *info = file_fb_info(file);
+	const struct fb_ops *fb;
+	long ret = -ENOIOCTLCMD;
+
+	if (!info)
+		return -ENODEV;
+	fb = info->fbops;
+	switch (cmd) {
+	case FBIOGET_VSCREENINFO:
+	case FBIOPUT_VSCREENINFO:
+	case FBIOPAN_DISPLAY:
+	case FBIOGET_CON2FBMAP:
+	case FBIOPUT_CON2FBMAP:
+		arg = (unsigned long) compat_ptr(arg);
+		fallthrough;
+	case FBIOBLANK:
+		ret = do_fb_ioctl(info, cmd, arg);
+		break;
+
+	case FBIOGET_FSCREENINFO:
+		ret = fb_get_fscreeninfo(info, cmd, arg);
+		break;
+
+	case FBIOGETCMAP:
+	case FBIOPUTCMAP:
+		ret = fb_getput_cmap(info, cmd, arg);
+		break;
+
+	default:
+		if (fb->fb_compat_ioctl)
+			ret = fb->fb_compat_ioctl(info, cmd, arg);
+		break;
+	}
+	return ret;
+}
+#endif
+
+static int fb_mmap(struct file *file, struct vm_area_struct *vma)
+{
+	struct fb_info *info = file_fb_info(file);
+	unsigned long mmio_pgoff;
+	unsigned long start;
+	u32 len;
+
+	if (!info)
+		return -ENODEV;
+	mutex_lock(&info->mm_lock);
+
+	if (info->fbops->fb_mmap) {
+		int res;
+
+		/*
+		 * The framebuffer needs to be accessed decrypted, be sure
+		 * SME protection is removed ahead of the call
+		 */
+		vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
+		res = info->fbops->fb_mmap(info, vma);
+		mutex_unlock(&info->mm_lock);
+		return res;
+#if IS_ENABLED(CONFIG_FB_DEFERRED_IO)
+	} else if (info->fbdefio) {
+		/*
+		 * FB deferred I/O wants you to handle mmap in your drivers. At a
+		 * minimum, point struct fb_ops.fb_mmap to fb_deferred_io_mmap().
+		 */
+		dev_warn_once(info->dev, "fbdev mmap not set up for deferred I/O.\n");
+		mutex_unlock(&info->mm_lock);
+		return -ENODEV;
+#endif
+	}
+
+	/*
+	 * Ugh. This can be either the frame buffer mapping, or
+	 * if pgoff points past it, the mmio mapping.
+	 */
+	start = info->fix.smem_start;
+	len = info->fix.smem_len;
+	mmio_pgoff = PAGE_ALIGN((start & ~PAGE_MASK) + len) >> PAGE_SHIFT;
+	if (vma->vm_pgoff >= mmio_pgoff) {
+		if (info->var.accel_flags) {
+			mutex_unlock(&info->mm_lock);
+			return -EINVAL;
+		}
+
+		vma->vm_pgoff -= mmio_pgoff;
+		start = info->fix.mmio_start;
+		len = info->fix.mmio_len;
+	}
+	mutex_unlock(&info->mm_lock);
+
+	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
+	fb_pgprotect(file, vma, start);
+
+	return vm_iomap_memory(vma, start, len);
+}
+
+static int fb_open(struct inode *inode, struct file *file)
+__acquires(&info->lock)
+__releases(&info->lock)
+{
+	int fbidx = iminor(inode);
+	struct fb_info *info;
+	int res = 0;
+
+	info = get_fb_info(fbidx);
+	if (!info) {
+		request_module("fb%d", fbidx);
+		info = get_fb_info(fbidx);
+		if (!info)
+			return -ENODEV;
+	}
+	if (IS_ERR(info))
+		return PTR_ERR(info);
+
+	lock_fb_info(info);
+	if (!try_module_get(info->fbops->owner)) {
+		res = -ENODEV;
+		goto out;
+	}
+	file->private_data = info;
+	if (info->fbops->fb_open) {
+		res = info->fbops->fb_open(info, 1);
+		if (res)
+			module_put(info->fbops->owner);
+	}
+#ifdef CONFIG_FB_DEFERRED_IO
+	if (info->fbdefio)
+		fb_deferred_io_open(info, inode, file);
+#endif
+out:
+	unlock_fb_info(info);
+	if (res)
+		put_fb_info(info);
+	return res;
+}
+
+static int fb_release(struct inode *inode, struct file *file)
+__acquires(&info->lock)
+__releases(&info->lock)
+{
+	struct fb_info * const info = file->private_data;
+
+	lock_fb_info(info);
+#if IS_ENABLED(CONFIG_FB_DEFERRED_IO)
+	if (info->fbdefio)
+		fb_deferred_io_release(info);
+#endif
+	if (info->fbops->fb_release)
+		info->fbops->fb_release(info, 1);
+	module_put(info->fbops->owner);
+	unlock_fb_info(info);
+	put_fb_info(info);
+	return 0;
+}
+
+#if defined(CONFIG_FB_PROVIDE_GET_FB_UNMAPPED_AREA) && !defined(CONFIG_MMU)
+static unsigned long get_fb_unmapped_area(struct file *filp,
+				   unsigned long addr, unsigned long len,
+				   unsigned long pgoff, unsigned long flags)
+{
+	struct fb_info * const info = filp->private_data;
+	unsigned long fb_size = PAGE_ALIGN(info->fix.smem_len);
+
+	if (pgoff > fb_size || len > fb_size - pgoff)
+		return -EINVAL;
+
+	return (unsigned long)info->screen_base + pgoff;
+}
+#endif
+
+static const struct file_operations fb_fops = {
+	.owner = THIS_MODULE,
+	.read = fb_read,
+	.write = fb_write,
+	.unlocked_ioctl = fb_ioctl,
+#ifdef CONFIG_COMPAT
+	.compat_ioctl = fb_compat_ioctl,
+#endif
+	.mmap = fb_mmap,
+	.open = fb_open,
+	.release = fb_release,
+#if defined(HAVE_ARCH_FB_UNMAPPED_AREA) || \
+	(defined(CONFIG_FB_PROVIDE_GET_FB_UNMAPPED_AREA) && \
+	 !defined(CONFIG_MMU))
+	.get_unmapped_area = get_fb_unmapped_area,
+#endif
+#ifdef CONFIG_FB_DEFERRED_IO
+	.fsync = fb_deferred_io_fsync,
+#endif
+	.llseek = default_llseek,
+};
+
+int fb_register_chrdev(void)
+{
+	int ret;
+
+	ret = register_chrdev(FB_MAJOR, "fb", &fb_fops);
+	if (ret) {
+		pr_err("Unable to get major %d for fb devs\n", FB_MAJOR);
+		return ret;
+	}
+
+	return ret;
+}
+
+void fb_unregister_chrdev(void)
+{
+	unregister_chrdev(FB_MAJOR, "fb");
+}
diff --git a/drivers/video/fbdev/core/fb_internal.h b/drivers/video/fbdev/core/fb_internal.h
index 51f7c9f04e45a..abe06c9da36e3 100644
--- a/drivers/video/fbdev/core/fb_internal.h
+++ b/drivers/video/fbdev/core/fb_internal.h
@@ -6,10 +6,16 @@ 
 #include <linux/fb.h>
 #include <linux/mutex.h>
 
+/* fb_devfs.c */
+int fb_register_chrdev(void);
+void fb_unregister_chrdev(void);
+
 /* fbmem.c */
 extern struct mutex registration_lock;
 extern struct fb_info *registered_fb[FB_MAX];
 extern int num_registered_fb;
+struct fb_info *get_fb_info(unsigned int idx);
+void put_fb_info(struct fb_info *fb_info);
 
 /* fb_procfs.c */
 int fb_init_procfs(void);
diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 536209901e32a..4edf70241a23c 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -13,11 +13,9 @@ 
 
 #include <linux/module.h>
 
-#include <linux/compat.h>
 #include <linux/types.h>
 #include <linux/errno.h>
 #include <linux/kernel.h>
-#include <linux/major.h>
 #include <linux/slab.h>
 #include <linux/mm.h>
 #include <linux/mman.h>
@@ -57,7 +55,7 @@  bool fb_center_logo __read_mostly;
 
 int fb_logo_count __read_mostly = -1;
 
-static struct fb_info *get_fb_info(unsigned int idx)
+struct fb_info *get_fb_info(unsigned int idx)
 {
 	struct fb_info *fb_info;
 
@@ -73,7 +71,7 @@  static struct fb_info *get_fb_info(unsigned int idx)
 	return fb_info;
 }
 
-static void put_fb_info(struct fb_info *fb_info)
+void put_fb_info(struct fb_info *fb_info)
 {
 	if (!refcount_dec_and_test(&fb_info->count))
 		return;
@@ -702,59 +700,6 @@  int fb_show_logo(struct fb_info *info, int rotate) { return 0; }
 EXPORT_SYMBOL(fb_prepare_logo);
 EXPORT_SYMBOL(fb_show_logo);
 
-/*
- * We hold a reference to the fb_info in file->private_data,
- * but if the current registered fb has changed, we don't
- * actually want to use it.
- *
- * So look up the fb_info using the inode minor number,
- * and just verify it against the reference we have.
- */
-static struct fb_info *file_fb_info(struct file *file)
-{
-	struct inode *inode = file_inode(file);
-	int fbidx = iminor(inode);
-	struct fb_info *info = registered_fb[fbidx];
-
-	if (info != file->private_data)
-		info = NULL;
-	return info;
-}
-
-static ssize_t
-fb_read(struct file *file, char __user *buf, size_t count, loff_t *ppos)
-{
-	struct fb_info *info = file_fb_info(file);
-
-	if (!info)
-		return -ENODEV;
-
-	if (info->state != FBINFO_STATE_RUNNING)
-		return -EPERM;
-
-	if (info->fbops->fb_read)
-		return info->fbops->fb_read(info, buf, count, ppos);
-
-	return fb_io_read(info, buf, count, ppos);
-}
-
-static ssize_t
-fb_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos)
-{
-	struct fb_info *info = file_fb_info(file);
-
-	if (!info)
-		return -ENODEV;
-
-	if (info->state != FBINFO_STATE_RUNNING)
-		return -EPERM;
-
-	if (info->fbops->fb_write)
-		return info->fbops->fb_write(info, buf, count, ppos);
-
-	return fb_io_write(info, buf, count, ppos);
-}
-
 int
 fb_pan_display(struct fb_info *info, struct fb_var_screeninfo *var)
 {
@@ -954,416 +899,6 @@  fb_blank(struct fb_info *info, int blank)
 }
 EXPORT_SYMBOL(fb_blank);
 
-static long do_fb_ioctl(struct fb_info *info, unsigned int cmd,
-			unsigned long arg)
-{
-	const struct fb_ops *fb;
-	struct fb_var_screeninfo var;
-	struct fb_fix_screeninfo fix;
-	struct fb_cmap cmap_from;
-	struct fb_cmap_user cmap;
-	void __user *argp = (void __user *)arg;
-	long ret = 0;
-
-	switch (cmd) {
-	case FBIOGET_VSCREENINFO:
-		lock_fb_info(info);
-		var = info->var;
-		unlock_fb_info(info);
-
-		ret = copy_to_user(argp, &var, sizeof(var)) ? -EFAULT : 0;
-		break;
-	case FBIOPUT_VSCREENINFO:
-		if (copy_from_user(&var, argp, sizeof(var)))
-			return -EFAULT;
-		/* only for kernel-internal use */
-		var.activate &= ~FB_ACTIVATE_KD_TEXT;
-		console_lock();
-		lock_fb_info(info);
-		ret = fbcon_modechange_possible(info, &var);
-		if (!ret)
-			ret = fb_set_var(info, &var);
-		if (!ret)
-			fbcon_update_vcs(info, var.activate & FB_ACTIVATE_ALL);
-		unlock_fb_info(info);
-		console_unlock();
-		if (!ret && copy_to_user(argp, &var, sizeof(var)))
-			ret = -EFAULT;
-		break;
-	case FBIOGET_FSCREENINFO:
-		lock_fb_info(info);
-		memcpy(&fix, &info->fix, sizeof(fix));
-		if (info->flags & FBINFO_HIDE_SMEM_START)
-			fix.smem_start = 0;
-		unlock_fb_info(info);
-
-		ret = copy_to_user(argp, &fix, sizeof(fix)) ? -EFAULT : 0;
-		break;
-	case FBIOPUTCMAP:
-		if (copy_from_user(&cmap, argp, sizeof(cmap)))
-			return -EFAULT;
-		ret = fb_set_user_cmap(&cmap, info);
-		break;
-	case FBIOGETCMAP:
-		if (copy_from_user(&cmap, argp, sizeof(cmap)))
-			return -EFAULT;
-		lock_fb_info(info);
-		cmap_from = info->cmap;
-		unlock_fb_info(info);
-		ret = fb_cmap_to_user(&cmap_from, &cmap);
-		break;
-	case FBIOPAN_DISPLAY:
-		if (copy_from_user(&var, argp, sizeof(var)))
-			return -EFAULT;
-		console_lock();
-		lock_fb_info(info);
-		ret = fb_pan_display(info, &var);
-		unlock_fb_info(info);
-		console_unlock();
-		if (ret == 0 && copy_to_user(argp, &var, sizeof(var)))
-			return -EFAULT;
-		break;
-	case FBIO_CURSOR:
-		ret = -EINVAL;
-		break;
-	case FBIOGET_CON2FBMAP:
-		ret = fbcon_get_con2fb_map_ioctl(argp);
-		break;
-	case FBIOPUT_CON2FBMAP:
-		ret = fbcon_set_con2fb_map_ioctl(argp);
-		break;
-	case FBIOBLANK:
-		if (arg > FB_BLANK_POWERDOWN)
-			return -EINVAL;
-		console_lock();
-		lock_fb_info(info);
-		ret = fb_blank(info, arg);
-		/* might again call into fb_blank */
-		fbcon_fb_blanked(info, arg);
-		unlock_fb_info(info);
-		console_unlock();
-		break;
-	default:
-		lock_fb_info(info);
-		fb = info->fbops;
-		if (fb->fb_ioctl)
-			ret = fb->fb_ioctl(info, cmd, arg);
-		else
-			ret = -ENOTTY;
-		unlock_fb_info(info);
-	}
-	return ret;
-}
-
-static long fb_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
-{
-	struct fb_info *info = file_fb_info(file);
-
-	if (!info)
-		return -ENODEV;
-	return do_fb_ioctl(info, cmd, arg);
-}
-
-#ifdef CONFIG_COMPAT
-struct fb_fix_screeninfo32 {
-	char			id[16];
-	compat_caddr_t		smem_start;
-	u32			smem_len;
-	u32			type;
-	u32			type_aux;
-	u32			visual;
-	u16			xpanstep;
-	u16			ypanstep;
-	u16			ywrapstep;
-	u32			line_length;
-	compat_caddr_t		mmio_start;
-	u32			mmio_len;
-	u32			accel;
-	u16			reserved[3];
-};
-
-struct fb_cmap32 {
-	u32			start;
-	u32			len;
-	compat_caddr_t	red;
-	compat_caddr_t	green;
-	compat_caddr_t	blue;
-	compat_caddr_t	transp;
-};
-
-static int fb_getput_cmap(struct fb_info *info, unsigned int cmd,
-			  unsigned long arg)
-{
-	struct fb_cmap32 cmap32;
-	struct fb_cmap cmap_from;
-	struct fb_cmap_user cmap;
-
-	if (copy_from_user(&cmap32, compat_ptr(arg), sizeof(cmap32)))
-		return -EFAULT;
-
-	cmap = (struct fb_cmap_user) {
-		.start	= cmap32.start,
-		.len	= cmap32.len,
-		.red	= compat_ptr(cmap32.red),
-		.green	= compat_ptr(cmap32.green),
-		.blue	= compat_ptr(cmap32.blue),
-		.transp	= compat_ptr(cmap32.transp),
-	};
-
-	if (cmd == FBIOPUTCMAP)
-		return fb_set_user_cmap(&cmap, info);
-
-	lock_fb_info(info);
-	cmap_from = info->cmap;
-	unlock_fb_info(info);
-
-	return fb_cmap_to_user(&cmap_from, &cmap);
-}
-
-static int do_fscreeninfo_to_user(struct fb_fix_screeninfo *fix,
-				  struct fb_fix_screeninfo32 __user *fix32)
-{
-	__u32 data;
-	int err;
-
-	err = copy_to_user(&fix32->id, &fix->id, sizeof(fix32->id));
-
-	data = (__u32) (unsigned long) fix->smem_start;
-	err |= put_user(data, &fix32->smem_start);
-
-	err |= put_user(fix->smem_len, &fix32->smem_len);
-	err |= put_user(fix->type, &fix32->type);
-	err |= put_user(fix->type_aux, &fix32->type_aux);
-	err |= put_user(fix->visual, &fix32->visual);
-	err |= put_user(fix->xpanstep, &fix32->xpanstep);
-	err |= put_user(fix->ypanstep, &fix32->ypanstep);
-	err |= put_user(fix->ywrapstep, &fix32->ywrapstep);
-	err |= put_user(fix->line_length, &fix32->line_length);
-
-	data = (__u32) (unsigned long) fix->mmio_start;
-	err |= put_user(data, &fix32->mmio_start);
-
-	err |= put_user(fix->mmio_len, &fix32->mmio_len);
-	err |= put_user(fix->accel, &fix32->accel);
-	err |= copy_to_user(fix32->reserved, fix->reserved,
-			    sizeof(fix->reserved));
-
-	if (err)
-		return -EFAULT;
-	return 0;
-}
-
-static int fb_get_fscreeninfo(struct fb_info *info, unsigned int cmd,
-			      unsigned long arg)
-{
-	struct fb_fix_screeninfo fix;
-
-	lock_fb_info(info);
-	fix = info->fix;
-	if (info->flags & FBINFO_HIDE_SMEM_START)
-		fix.smem_start = 0;
-	unlock_fb_info(info);
-	return do_fscreeninfo_to_user(&fix, compat_ptr(arg));
-}
-
-static long fb_compat_ioctl(struct file *file, unsigned int cmd,
-			    unsigned long arg)
-{
-	struct fb_info *info = file_fb_info(file);
-	const struct fb_ops *fb;
-	long ret = -ENOIOCTLCMD;
-
-	if (!info)
-		return -ENODEV;
-	fb = info->fbops;
-	switch(cmd) {
-	case FBIOGET_VSCREENINFO:
-	case FBIOPUT_VSCREENINFO:
-	case FBIOPAN_DISPLAY:
-	case FBIOGET_CON2FBMAP:
-	case FBIOPUT_CON2FBMAP:
-		arg = (unsigned long) compat_ptr(arg);
-		fallthrough;
-	case FBIOBLANK:
-		ret = do_fb_ioctl(info, cmd, arg);
-		break;
-
-	case FBIOGET_FSCREENINFO:
-		ret = fb_get_fscreeninfo(info, cmd, arg);
-		break;
-
-	case FBIOGETCMAP:
-	case FBIOPUTCMAP:
-		ret = fb_getput_cmap(info, cmd, arg);
-		break;
-
-	default:
-		if (fb->fb_compat_ioctl)
-			ret = fb->fb_compat_ioctl(info, cmd, arg);
-		break;
-	}
-	return ret;
-}
-#endif
-
-static int
-fb_mmap(struct file *file, struct vm_area_struct * vma)
-{
-	struct fb_info *info = file_fb_info(file);
-	unsigned long mmio_pgoff;
-	unsigned long start;
-	u32 len;
-
-	if (!info)
-		return -ENODEV;
-	mutex_lock(&info->mm_lock);
-
-	if (info->fbops->fb_mmap) {
-		int res;
-
-		/*
-		 * The framebuffer needs to be accessed decrypted, be sure
-		 * SME protection is removed ahead of the call
-		 */
-		vma->vm_page_prot = pgprot_decrypted(vma->vm_page_prot);
-		res = info->fbops->fb_mmap(info, vma);
-		mutex_unlock(&info->mm_lock);
-		return res;
-#if IS_ENABLED(CONFIG_FB_DEFERRED_IO)
-	} else if (info->fbdefio) {
-		/*
-		 * FB deferred I/O wants you to handle mmap in your drivers. At a
-		 * minimum, point struct fb_ops.fb_mmap to fb_deferred_io_mmap().
-		 */
-		dev_warn_once(info->dev, "fbdev mmap not set up for deferred I/O.\n");
-		mutex_unlock(&info->mm_lock);
-		return -ENODEV;
-#endif
-	}
-
-	/*
-	 * Ugh. This can be either the frame buffer mapping, or
-	 * if pgoff points past it, the mmio mapping.
-	 */
-	start = info->fix.smem_start;
-	len = info->fix.smem_len;
-	mmio_pgoff = PAGE_ALIGN((start & ~PAGE_MASK) + len) >> PAGE_SHIFT;
-	if (vma->vm_pgoff >= mmio_pgoff) {
-		if (info->var.accel_flags) {
-			mutex_unlock(&info->mm_lock);
-			return -EINVAL;
-		}
-
-		vma->vm_pgoff -= mmio_pgoff;
-		start = info->fix.mmio_start;
-		len = info->fix.mmio_len;
-	}
-	mutex_unlock(&info->mm_lock);
-
-	vma->vm_page_prot = vm_get_page_prot(vma->vm_flags);
-	fb_pgprotect(file, vma, start);
-
-	return vm_iomap_memory(vma, start, len);
-}
-
-static int
-fb_open(struct inode *inode, struct file *file)
-__acquires(&info->lock)
-__releases(&info->lock)
-{
-	int fbidx = iminor(inode);
-	struct fb_info *info;
-	int res = 0;
-
-	info = get_fb_info(fbidx);
-	if (!info) {
-		request_module("fb%d", fbidx);
-		info = get_fb_info(fbidx);
-		if (!info)
-			return -ENODEV;
-	}
-	if (IS_ERR(info))
-		return PTR_ERR(info);
-
-	lock_fb_info(info);
-	if (!try_module_get(info->fbops->owner)) {
-		res = -ENODEV;
-		goto out;
-	}
-	file->private_data = info;
-	if (info->fbops->fb_open) {
-		res = info->fbops->fb_open(info,1);
-		if (res)
-			module_put(info->fbops->owner);
-	}
-#ifdef CONFIG_FB_DEFERRED_IO
-	if (info->fbdefio)
-		fb_deferred_io_open(info, inode, file);
-#endif
-out:
-	unlock_fb_info(info);
-	if (res)
-		put_fb_info(info);
-	return res;
-}
-
-static int
-fb_release(struct inode *inode, struct file *file)
-__acquires(&info->lock)
-__releases(&info->lock)
-{
-	struct fb_info * const info = file->private_data;
-
-	lock_fb_info(info);
-#if IS_ENABLED(CONFIG_FB_DEFERRED_IO)
-	if (info->fbdefio)
-		fb_deferred_io_release(info);
-#endif
-	if (info->fbops->fb_release)
-		info->fbops->fb_release(info,1);
-	module_put(info->fbops->owner);
-	unlock_fb_info(info);
-	put_fb_info(info);
-	return 0;
-}
-
-#if defined(CONFIG_FB_PROVIDE_GET_FB_UNMAPPED_AREA) && !defined(CONFIG_MMU)
-static unsigned long get_fb_unmapped_area(struct file *filp,
-				   unsigned long addr, unsigned long len,
-				   unsigned long pgoff, unsigned long flags)
-{
-	struct fb_info * const info = filp->private_data;
-	unsigned long fb_size = PAGE_ALIGN(info->fix.smem_len);
-
-	if (pgoff > fb_size || len > fb_size - pgoff)
-		return -EINVAL;
-
-	return (unsigned long)info->screen_base + pgoff;
-}
-#endif
-
-static const struct file_operations fb_fops = {
-	.owner =	THIS_MODULE,
-	.read =		fb_read,
-	.write =	fb_write,
-	.unlocked_ioctl = fb_ioctl,
-#ifdef CONFIG_COMPAT
-	.compat_ioctl = fb_compat_ioctl,
-#endif
-	.mmap =		fb_mmap,
-	.open =		fb_open,
-	.release =	fb_release,
-#if defined(HAVE_ARCH_FB_UNMAPPED_AREA) || \
-	(defined(CONFIG_FB_PROVIDE_GET_FB_UNMAPPED_AREA) && \
-	 !defined(CONFIG_MMU))
-	.get_unmapped_area = get_fb_unmapped_area,
-#endif
-#ifdef CONFIG_FB_DEFERRED_IO
-	.fsync =	fb_deferred_io_fsync,
-#endif
-	.llseek =	default_llseek,
-};
-
 struct class *fb_class;
 EXPORT_SYMBOL(fb_class);
 
@@ -1591,11 +1126,9 @@  fbmem_init(void)
 	if (ret)
 		return ret;
 
-	ret = register_chrdev(FB_MAJOR, "fb", &fb_fops);
-	if (ret) {
-		printk("unable to get major %d for fb devs\n", FB_MAJOR);
+	ret = fb_register_chrdev();
+	if (ret)
 		goto err_chrdev;
-	}
 
 	fb_class = class_create("graphics");
 	if (IS_ERR(fb_class)) {
@@ -1610,7 +1143,7 @@  fbmem_init(void)
 	return 0;
 
 err_class:
-	unregister_chrdev(FB_MAJOR, "fb");
+	fb_unregister_chrdev();
 err_chrdev:
 	fb_cleanup_procfs();
 	return ret;
@@ -1625,7 +1158,7 @@  fbmem_exit(void)
 
 	fb_cleanup_procfs();
 	class_destroy(fb_class);
-	unregister_chrdev(FB_MAJOR, "fb");
+	fb_unregister_chrdev();
 }
 
 module_exit(fbmem_exit);