[PATCH v2 0/8] drivers: Transition to the faux device interface

[PATCH v2 0/8] drivers: Transition to the faux device interface

[Sudeep Holla]

Recently when debugging why one of the scmi platform device was not
showing up under /sys/devices/platform/firmware:scmi instead was
appearing directly under /sys/devices/platform, I noticed the new
faux interface /sys/devices/faux.

Looking through the discussion and the background, I got excited and
took the opportunity to clear all the platform devices under
/sys/devices/platform on the Arm Juno/FVP platforms that are really
faux devices. Only the platform devices created for the device nodes
from the DT remain under /sys/devices/platform after these changes.

All the patches are independent of each other and are part of the series
just to demonstrate the use of macro module_faux_driver() where
applicable. The idea is to get the macro merged first and then push the
individual patches via respective subsystem later.

Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
Changes in v2:
- Dropped all the modalias expect efivars(reason in the patch)
- Defined new helper macro module_faux_driver() and moved most of the
  drivers to use it
- Dropped already queued ASoC and regulator changes
- Link to v1: https://lore.kernel.org/r/20250317-plat2faux_dev-v1-0-5fe67c085ad5@arm.com

---
Sudeep Holla (8):
      driver core: add helper macro for module_faux_driver() boilerplate
      cpuidle: psci: Transition to the faux device interface
      hwrng: arm-smccc-trng - transition to the faux device interface
      rtc: efi: Transition to the faux device interface
      virt: efi_secret: Transition to the faux device interface
      efi: efivars: Transition to the faux device interface
      ACPI: APEI: EINJ: Transition to the faux device interface
      net: phy: fixed_phy: transition to the faux device interface

 drivers/acpi/apei/einj-core.c             | 51 ++++---------------------------
 drivers/char/hw_random/arm_smccc_trng.c   | 19 +++++-------
 drivers/cpuidle/cpuidle-psci.c            | 32 +++----------------
 drivers/firmware/efi/efi-pstore.c         |  2 +-
 drivers/firmware/efi/efi.c                | 12 ++------
 drivers/firmware/smccc/smccc.c            | 17 -----------
 drivers/net/phy/fixed_phy.c               | 16 +++++-----
 drivers/rtc/rtc-efi.c                     | 16 +++-------
 drivers/virt/coco/efi_secret/efi_secret.c | 29 +++++-------------
 include/linux/device/faux.h               | 49 +++++++++++++++++++++++++++++
 10 files changed, 90 insertions(+), 153 deletions(-)
---
base-commit: 4701f33a10702d5fc577c32434eb62adde0a1ae1
change-id: 20250315-plat2faux_dev-8c28b35be96a
-- 
Regards,
Sudeep

[PATCH v2 4/8] rtc: efi: Transition to the faux device interface

[Sudeep Holla]

The EFI RTC driver does not require the creation of a platform device.
Originally, this approach was chosen for simplicity when the driver was
first implemented.

With the introduction of the lightweight faux device interface, we now
have a more appropriate alternative. Migrate the driver to utilize the
faux bus, given that the platform device it previously created was not
a real one anyway. This will simplify the code, reducing its footprint
while maintaining functionality.

Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: Alexandre Belloni <alexandre.belloni@bootlin.com>
Cc: linux-rtc@vger.kernel.org
Cc: linux-efi@vger.kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/efi/efi.c |  3 ---
 drivers/rtc/rtc-efi.c      | 16 +++++-----------
 2 files changed, 5 insertions(+), 14 deletions(-)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 7309394b8fc98cf7a3424af209b752f0251c8c89..8aebc747c65bc1b63d514a50fe6f35a9e3c1af0a 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -427,9 +427,6 @@ static int __init efisubsys_init(void)
 		}
 	}
 
-	if (efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES))
-		platform_device_register_simple("rtc-efi", 0, NULL, 0);
-
 	/* We register the efi directory at /sys/firmware/efi */
 	efi_kobj = kobject_create_and_add("efi", firmware_kobj);
 	if (!efi_kobj) {
diff --git a/drivers/rtc/rtc-efi.c b/drivers/rtc/rtc-efi.c
index fa8bf82df9488e7d1c23c058b4a3032dde74bc6e..681d917d541e51b37f2d59b0567caf6aa8bf05f4 100644
--- a/drivers/rtc/rtc-efi.c
+++ b/drivers/rtc/rtc-efi.c
@@ -14,7 +14,7 @@
 #include <linux/module.h>
 #include <linux/stringify.h>
 #include <linux/time.h>
-#include <linux/platform_device.h>
+#include <linux/device/faux.h>
 #include <linux/rtc.h>
 #include <linux/efi.h>
 
@@ -254,7 +254,7 @@ static const struct rtc_class_ops efi_rtc_ops = {
 	.proc		= efi_procfs,
 };
 
-static int __init efi_rtc_probe(struct platform_device *dev)
+static int __init efi_rtc_probe(struct faux_device *dev)
 {
 	struct rtc_device *rtc;
 	efi_time_t eft;
@@ -268,7 +268,7 @@ static int __init efi_rtc_probe(struct platform_device *dev)
 	if (IS_ERR(rtc))
 		return PTR_ERR(rtc);
 
-	platform_set_drvdata(dev, rtc);
+	faux_device_set_drvdata(dev, rtc);
 
 	rtc->ops = &efi_rtc_ops;
 	clear_bit(RTC_FEATURE_UPDATE_INTERRUPT, rtc->features);
@@ -282,15 +282,9 @@ static int __init efi_rtc_probe(struct platform_device *dev)
 	return devm_rtc_register_device(rtc);
 }
 
-static struct platform_driver efi_rtc_driver = {
-	.driver = {
-		.name = "rtc-efi",
-	},
-};
-
-module_platform_driver_probe(efi_rtc_driver, efi_rtc_probe);
+module_faux_driver(rtc_efi, efi_rtc_probe, NULL,
+		   efi_rt_services_supported(EFI_RT_SUPPORTED_TIME_SERVICES));
 
 MODULE_AUTHOR("dann frazier <dannf@dannf.org>");
 MODULE_LICENSE("GPL");
 MODULE_DESCRIPTION("EFI RTC driver");
-MODULE_ALIAS("platform:rtc-efi");

-- 
2.34.1

Re: (subset) [PATCH v2 4/8] rtc: efi: Transition to the faux device interface

[Alexandre Belloni]

On Tue, 18 Mar 2025 17:01:42 +0000, Sudeep Holla wrote:
> The EFI RTC driver does not require the creation of a platform device.
> Originally, this approach was chosen for simplicity when the driver was
> first implemented.
> 
> With the introduction of the lightweight faux device interface, we now
> have a more appropriate alternative. Migrate the driver to utilize the
> faux bus, given that the platform device it previously created was not
> a real one anyway. This will simplify the code, reducing its footprint
> while maintaining functionality.
> 
> [...]

Applied, thanks!

[4/8] rtc: efi: Transition to the faux device interface
      https://git.kernel.org/abelloni/c/89a378d01e7e

Best regards,

-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: (subset) [PATCH v2 4/8] rtc: efi: Transition to the faux device interface

[Sudeep Holla]

On Tue, Apr 08, 2025 at 04:45:31PM +0200, Alexandre Belloni wrote:
> On Tue, 18 Mar 2025 17:01:42 +0000, Sudeep Holla wrote:
> > The EFI RTC driver does not require the creation of a platform device.
> > Originally, this approach was chosen for simplicity when the driver was
> > first implemented.
> > 
> > With the introduction of the lightweight faux device interface, we now
> > have a more appropriate alternative. Migrate the driver to utilize the
> > faux bus, given that the platform device it previously created was not
> > a real one anyway. This will simplify the code, reducing its footprint
> > while maintaining functionality.
> > 
> > [...]
> 
> Applied, thanks!
> 
> [4/8] rtc: efi: Transition to the faux device interface
>       https://git.kernel.org/abelloni/c/89a378d01e7e
> 

You need to drop it, sorry for not mentioning it explicitly.
module alias doesn't work which I think is a requirement and also
module_faux_driver() macro is not upstream.

Sorry for the trouble.

-- 
Regards,
Sudeep

[PATCH v2 5/8] virt: efi_secret: Transition to the faux device interface

[Sudeep Holla]

The EFI secret area driver does not require the creation of a platform
device. Originally, this approach was chosen for simplicity when the
driver was first implemented.

With the introduction of the lightweight faux device interface, we now
have a more appropriate alternative. Migrate the driver to utilize the
faux bus, given that the platform device it previously created was not
a real one anyway. This will simplify the code, reducing its footprint
while maintaining functionality.

Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/efi/efi.c                |  5 -----
 drivers/virt/coco/efi_secret/efi_secret.c | 29 ++++++++---------------------
 2 files changed, 8 insertions(+), 26 deletions(-)

diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 8aebc747c65bc1b63d514a50fe6f35a9e3c1af0a..862b7744c28ecc9e5a64bbb3533c34119f50267f 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -465,11 +465,6 @@ static int __init efisubsys_init(void)
 	if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
 		efi_debugfs_init();
 
-#ifdef CONFIG_EFI_COCO_SECRET
-	if (efi.coco_secret != EFI_INVALID_TABLE_ADDR)
-		platform_device_register_simple("efi_secret", 0, NULL, 0);
-#endif
-
 	return 0;
 
 err_remove_group:
diff --git a/drivers/virt/coco/efi_secret/efi_secret.c b/drivers/virt/coco/efi_secret/efi_secret.c
index 1864f9f80617e082feb574a15327949972c8cc1e..a60976750bef787c78401bf4569ee5d0c7d2b5f4 100644
--- a/drivers/virt/coco/efi_secret/efi_secret.c
+++ b/drivers/virt/coco/efi_secret/efi_secret.c
@@ -16,7 +16,7 @@
  * is the GUID of the secret entry, and its content is the secret data.
  */
 
-#include <linux/platform_device.h>
+#include <linux/device/faux.h>
 #include <linux/seq_file.h>
 #include <linux/fs.h>
 #include <linux/kernel.h>
@@ -152,17 +152,12 @@ static const struct inode_operations efi_secret_dir_inode_operations = {
 	.unlink         = efi_secret_unlink,
 };
 
-static int efi_secret_map_area(struct platform_device *dev)
+static int efi_secret_map_area(struct faux_device *dev)
 {
 	int ret;
 	struct efi_secret *s = efi_secret_get();
 	struct linux_efi_coco_secret_area *secret_area;
 
-	if (efi.coco_secret == EFI_INVALID_TABLE_ADDR) {
-		dev_err(&dev->dev, "Secret area address is not available\n");
-		return -EINVAL;
-	}
-
 	secret_area = memremap(efi.coco_secret, sizeof(*secret_area), MEMREMAP_WB);
 	if (secret_area == NULL) {
 		dev_err(&dev->dev, "Could not map secret area EFI config entry\n");
@@ -191,7 +186,7 @@ static int efi_secret_map_area(struct platform_device *dev)
 	return ret;
 }
 
-static void efi_secret_securityfs_teardown(struct platform_device *dev)
+static void efi_secret_securityfs_teardown(struct faux_device *dev)
 {
 	struct efi_secret *s = efi_secret_get();
 	int i;
@@ -210,7 +205,7 @@ static void efi_secret_securityfs_teardown(struct platform_device *dev)
 	dev_dbg(&dev->dev, "Removed securityfs entries\n");
 }
 
-static int efi_secret_securityfs_setup(struct platform_device *dev)
+static int efi_secret_securityfs_setup(struct faux_device *dev)
 {
 	struct efi_secret *s = efi_secret_get();
 	int ret = 0, i = 0, bytes_left;
@@ -307,7 +302,7 @@ static void efi_secret_unmap_area(void)
 	}
 }
 
-static int efi_secret_probe(struct platform_device *dev)
+static int efi_secret_probe(struct faux_device *dev)
 {
 	int ret;
 
@@ -326,23 +321,15 @@ static int efi_secret_probe(struct platform_device *dev)
 	return ret;
 }
 
-static void efi_secret_remove(struct platform_device *dev)
+static void efi_secret_remove(struct faux_device *dev)
 {
 	efi_secret_securityfs_teardown(dev);
 	efi_secret_unmap_area();
 }
 
-static struct platform_driver efi_secret_driver = {
-	.probe = efi_secret_probe,
-	.remove = efi_secret_remove,
-	.driver = {
-		.name = "efi_secret",
-	},
-};
-
-module_platform_driver(efi_secret_driver);
+module_faux_driver(efi_secret, efi_secret_probe, efi_secret_remove,
+		   efi.coco_secret != EFI_INVALID_TABLE_ADDR);
 
 MODULE_DESCRIPTION("Confidential computing EFI secret area access");
 MODULE_AUTHOR("IBM");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:efi_secret");

-- 
2.34.1

Re: [PATCH v2 5/8] virt: efi_secret: Transition to the faux device interface

[Ard Biesheuvel]

On Tue, 18 Mar 2025 at 18:02, Sudeep Holla <sudeep.holla@arm.com> wrote:
>
> The EFI secret area driver does not require the creation of a platform
> device. Originally, this approach was chosen for simplicity when the
> driver was first implemented.
>
> With the introduction of the lightweight faux device interface, we now
> have a more appropriate alternative. Migrate the driver to utilize the
> faux bus, given that the platform device it previously created was not
> a real one anyway. This will simplify the code, reducing its footprint
> while maintaining functionality.
>
> Cc: Ard Biesheuvel <ardb@kernel.org>
> Cc: linux-efi@vger.kernel.org
> Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>

So how is module autoload supposed to work with this driver?


> ---
>  drivers/firmware/efi/efi.c                |  5 -----
>  drivers/virt/coco/efi_secret/efi_secret.c | 29 ++++++++---------------------
>  2 files changed, 8 insertions(+), 26 deletions(-)
>
> diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
> index 8aebc747c65bc1b63d514a50fe6f35a9e3c1af0a..862b7744c28ecc9e5a64bbb3533c34119f50267f 100644
> --- a/drivers/firmware/efi/efi.c
> +++ b/drivers/firmware/efi/efi.c
> @@ -465,11 +465,6 @@ static int __init efisubsys_init(void)
>         if (efi_enabled(EFI_DBG) && efi_enabled(EFI_PRESERVE_BS_REGIONS))
>                 efi_debugfs_init();
>
> -#ifdef CONFIG_EFI_COCO_SECRET
> -       if (efi.coco_secret != EFI_INVALID_TABLE_ADDR)
> -               platform_device_register_simple("efi_secret", 0, NULL, 0);
> -#endif
> -
>         return 0;
>
>  err_remove_group:
> diff --git a/drivers/virt/coco/efi_secret/efi_secret.c b/drivers/virt/coco/efi_secret/efi_secret.c
> index 1864f9f80617e082feb574a15327949972c8cc1e..a60976750bef787c78401bf4569ee5d0c7d2b5f4 100644
> --- a/drivers/virt/coco/efi_secret/efi_secret.c
> +++ b/drivers/virt/coco/efi_secret/efi_secret.c
> @@ -16,7 +16,7 @@
>   * is the GUID of the secret entry, and its content is the secret data.
>   */
>
> -#include <linux/platform_device.h>
> +#include <linux/device/faux.h>
>  #include <linux/seq_file.h>
>  #include <linux/fs.h>
>  #include <linux/kernel.h>
> @@ -152,17 +152,12 @@ static const struct inode_operations efi_secret_dir_inode_operations = {
>         .unlink         = efi_secret_unlink,
>  };
>
> -static int efi_secret_map_area(struct platform_device *dev)
> +static int efi_secret_map_area(struct faux_device *dev)
>  {
>         int ret;
>         struct efi_secret *s = efi_secret_get();
>         struct linux_efi_coco_secret_area *secret_area;
>
> -       if (efi.coco_secret == EFI_INVALID_TABLE_ADDR) {
> -               dev_err(&dev->dev, "Secret area address is not available\n");
> -               return -EINVAL;
> -       }
> -
>         secret_area = memremap(efi.coco_secret, sizeof(*secret_area), MEMREMAP_WB);
>         if (secret_area == NULL) {
>                 dev_err(&dev->dev, "Could not map secret area EFI config entry\n");
> @@ -191,7 +186,7 @@ static int efi_secret_map_area(struct platform_device *dev)
>         return ret;
>  }
>
> -static void efi_secret_securityfs_teardown(struct platform_device *dev)
> +static void efi_secret_securityfs_teardown(struct faux_device *dev)
>  {
>         struct efi_secret *s = efi_secret_get();
>         int i;
> @@ -210,7 +205,7 @@ static void efi_secret_securityfs_teardown(struct platform_device *dev)
>         dev_dbg(&dev->dev, "Removed securityfs entries\n");
>  }
>
> -static int efi_secret_securityfs_setup(struct platform_device *dev)
> +static int efi_secret_securityfs_setup(struct faux_device *dev)
>  {
>         struct efi_secret *s = efi_secret_get();
>         int ret = 0, i = 0, bytes_left;
> @@ -307,7 +302,7 @@ static void efi_secret_unmap_area(void)
>         }
>  }
>
> -static int efi_secret_probe(struct platform_device *dev)
> +static int efi_secret_probe(struct faux_device *dev)
>  {
>         int ret;
>
> @@ -326,23 +321,15 @@ static int efi_secret_probe(struct platform_device *dev)
>         return ret;
>  }
>
> -static void efi_secret_remove(struct platform_device *dev)
> +static void efi_secret_remove(struct faux_device *dev)
>  {
>         efi_secret_securityfs_teardown(dev);
>         efi_secret_unmap_area();
>  }
>
> -static struct platform_driver efi_secret_driver = {
> -       .probe = efi_secret_probe,
> -       .remove = efi_secret_remove,
> -       .driver = {
> -               .name = "efi_secret",
> -       },
> -};
> -
> -module_platform_driver(efi_secret_driver);
> +module_faux_driver(efi_secret, efi_secret_probe, efi_secret_remove,
> +                  efi.coco_secret != EFI_INVALID_TABLE_ADDR);
>
>  MODULE_DESCRIPTION("Confidential computing EFI secret area access");
>  MODULE_AUTHOR("IBM");
>  MODULE_LICENSE("GPL");
> -MODULE_ALIAS("platform:efi_secret");
>
> --
> 2.34.1
>

Re: [PATCH v2 5/8] virt: efi_secret: Transition to the faux device interface

[Sudeep Holla]

On Tue, Mar 18, 2025 at 06:10:41PM +0100, Ard Biesheuvel wrote:
> On Tue, 18 Mar 2025 at 18:02, Sudeep Holla <sudeep.holla@arm.com> wrote:
> >
> > The EFI secret area driver does not require the creation of a platform
> > device. Originally, this approach was chosen for simplicity when the
> > driver was first implemented.
> >
> > With the introduction of the lightweight faux device interface, we now
> > have a more appropriate alternative. Migrate the driver to utilize the
> > faux bus, given that the platform device it previously created was not
> > a real one anyway. This will simplify the code, reducing its footprint
> > while maintaining functionality.
> >
> > Cc: Ard Biesheuvel <ardb@kernel.org>
> > Cc: linux-efi@vger.kernel.org
> > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> 
> So how is module autoload supposed to work with this driver?
> 

IIUC, you are right. It doesn't work. I got carried away how efi_pstore was
autoloaded in Ubuntu even without alias or platform/faux device creation. I
don't know how yet but that works. This modules doesn't.

So we may have to retain platform device/driver for autoloading reasons ?

-- 
Regards,
Sudeep

Re: [PATCH v2 5/8] virt: efi_secret: Transition to the faux device interface

[Greg Kroah-Hartman]

On Wed, Mar 19, 2025 at 01:15:38PM +0000, Sudeep Holla wrote:
> On Tue, Mar 18, 2025 at 06:10:41PM +0100, Ard Biesheuvel wrote:
> > On Tue, 18 Mar 2025 at 18:02, Sudeep Holla <sudeep.holla@arm.com> wrote:
> > >
> > > The EFI secret area driver does not require the creation of a platform
> > > device. Originally, this approach was chosen for simplicity when the
> > > driver was first implemented.
> > >
> > > With the introduction of the lightweight faux device interface, we now
> > > have a more appropriate alternative. Migrate the driver to utilize the
> > > faux bus, given that the platform device it previously created was not
> > > a real one anyway. This will simplify the code, reducing its footprint
> > > while maintaining functionality.
> > >
> > > Cc: Ard Biesheuvel <ardb@kernel.org>
> > > Cc: linux-efi@vger.kernel.org
> > > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> > 
> > So how is module autoload supposed to work with this driver?
> > 
> 
> IIUC, you are right. It doesn't work. I got carried away how efi_pstore was
> autoloaded in Ubuntu even without alias or platform/faux device creation. I
> don't know how yet but that works. This modules doesn't.
> 
> So we may have to retain platform device/driver for autoloading reasons ?

If that's required, yes.

Re: [PATCH v2 5/8] virt: efi_secret: Transition to the faux device interface

[Sudeep Holla]

On Wed, Mar 19, 2025 at 07:24:53AM -0700, Greg Kroah-Hartman wrote:
> On Wed, Mar 19, 2025 at 01:15:38PM +0000, Sudeep Holla wrote:
> > On Tue, Mar 18, 2025 at 06:10:41PM +0100, Ard Biesheuvel wrote:
> > > On Tue, 18 Mar 2025 at 18:02, Sudeep Holla <sudeep.holla@arm.com> wrote:
> > > >
> > > > The EFI secret area driver does not require the creation of a platform
> > > > device. Originally, this approach was chosen for simplicity when the
> > > > driver was first implemented.
> > > >
> > > > With the introduction of the lightweight faux device interface, we now
> > > > have a more appropriate alternative. Migrate the driver to utilize the
> > > > faux bus, given that the platform device it previously created was not
> > > > a real one anyway. This will simplify the code, reducing its footprint
> > > > while maintaining functionality.
> > > >
> > > > Cc: Ard Biesheuvel <ardb@kernel.org>
> > > > Cc: linux-efi@vger.kernel.org
> > > > Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
> > > 
> > > So how is module autoload supposed to work with this driver?
> > > 
> > 
> > IIUC, you are right. It doesn't work. I got carried away how efi_pstore was
> > autoloaded in Ubuntu even without alias or platform/faux device creation. I
> > don't know how yet but that works. This modules doesn't.
> > 
> > So we may have to retain platform device/driver for autoloading reasons ?
> 
> If that's required, yes.

Thanks for confirming. I will drop this and see if autoloading is needed
in any other modules as well.

-- 
Regards,
Sudeep

[PATCH v2 6/8] efi: efivars: Transition to the faux device interface

[Sudeep Holla]

The "efivars" platform device is created just to enable the efi-pstore
module to autoload based on it. It doesn't have to be platform device
though. Originally, this approach was chosen for simplicity when the
driver was first implemented.

With the introduction of the lightweight faux device interface, we now
have a more appropriate alternative. Migrate this efivars device to
utilize the faux bus, given that the platform device it previously
created was not a real one anyway.

The modalias is retained here as efi-pstore module is dependent on it.

Cc: Ard Biesheuvel <ardb@kernel.org>
Cc: linux-efi@vger.kernel.org
Signed-off-by: Sudeep Holla <sudeep.holla@arm.com>
---
 drivers/firmware/efi/efi-pstore.c | 2 +-
 drivers/firmware/efi/efi.c        | 4 ++--
 2 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/firmware/efi/efi-pstore.c b/drivers/firmware/efi/efi-pstore.c
index a253b61449459eca31afc6ca780a20c4557659ba..eed756a59bba3b5a58cd2e238400c3c12fd5edd5 100644
--- a/drivers/firmware/efi/efi-pstore.c
+++ b/drivers/firmware/efi/efi-pstore.c
@@ -301,4 +301,4 @@ module_exit(efivars_pstore_exit);
 
 MODULE_DESCRIPTION("EFI variable backend for pstore");
 MODULE_LICENSE("GPL");
-MODULE_ALIAS("platform:efivars");
+MODULE_ALIAS("faux:efivars");
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 862b7744c28ecc9e5a64bbb3533c34119f50267f..dc5c24a7ca540cac342ceddcdbf75b55bf82c889 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -24,7 +24,7 @@
 #include <linux/initrd.h>
 #include <linux/io.h>
 #include <linux/kexec.h>
-#include <linux/platform_device.h>
+#include <linux/device/faux.h>
 #include <linux/random.h>
 #include <linux/reboot.h>
 #include <linux/slab.h>
@@ -443,7 +443,7 @@ static int __init efisubsys_init(void)
 		error = efivar_ssdt_load();
 		if (error)
 			pr_err("efi: failed to load SSDT, error %d.\n", error);
-		platform_device_register_simple("efivars", 0, NULL, 0);
+		faux_device_create("efivars", NULL, NULL);
 	}
 
 	BLOCKING_INIT_NOTIFIER_HEAD(&efivar_ops_nh);

-- 
2.34.1