From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6AE30C4332F for ; Mon, 11 Oct 2021 17:46:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 468A560F11 for ; Mon, 11 Oct 2021 17:46:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231617AbhJKRsP (ORCPT ); Mon, 11 Oct 2021 13:48:15 -0400 Received: from mail.kernel.org ([198.145.29.99]:35064 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230102AbhJKRsH (ORCPT ); Mon, 11 Oct 2021 13:48:07 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 1D88D60F11; Mon, 11 Oct 2021 17:46:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1633974366; bh=4TBfE9Rzk3TgLICfxbmtsZgSk07WQpuq6KQNlcoRChM=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=mAKTONy3TU/ziCpABOZkrPunxgKX0Y13t5JUj+3yISi8P38M0v7ccfzBEAwloWjgN FZ3Tw3aUzUlN13EwdzlzsVlmQvkp5DNFhFC7mBvDLaXVafw89iQyPd5YDzmYv1Mc9d q3TFN2+cOoPRX3u5JDcCeJYjXf+vkq2fck5RVjrU= Date: Mon, 11 Oct 2021 19:46:04 +0200 From: Greg KH To: Luis Chamberlain Cc: bp@suse.de, akpm@linux-foundation.org, josh@joshtriplett.org, rishabhb@codeaurora.org, kubakici@wp.pl, maco@android.com, david.brown@linaro.org, bjorn.andersson@linaro.org, linux-wireless@vger.kernel.org, keescook@chromium.org, shuah@kernel.org, mfuzzey@parkeon.com, zohar@linux.vnet.ibm.com, dhowells@redhat.com, pali.rohar@gmail.com, tiwai@suse.de, arend.vanspriel@broadcom.com, zajec5@gmail.com, nbroeking@me.com, broonie@kernel.org, dmitry.torokhov@gmail.com, dwmw2@infradead.org, torvalds@linux-foundation.org, Abhay_Salunke@dell.com, jewalt@lgsinnovations.com, cantabile.desu@gmail.com, ast@fb.com, andresx7@gmail.com, dan.rue@linaro.org, brendanhiggins@google.com, yzaikin@google.com, sfr@canb.auug.org.au, rdunlap@infradead.org, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH 04/14] firmware_loader: add built-in firmware kconfig entry Message-ID: References: <20210917182226.3532898-1-mcgrof@kernel.org> <20210917182226.3532898-5-mcgrof@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 11, 2021 at 10:35:37AM -0700, Luis Chamberlain wrote: > On Tue, Oct 05, 2021 at 04:30:06PM +0200, Greg KH wrote: > > On Fri, Sep 17, 2021 at 11:22:16AM -0700, Luis R. Rodriguez wrote: > > > From: Luis Chamberlain > > > > > > The built-in firmware is always supported when a user enables > > > FW_LOADER=y today, that is, it is built-in to the kernel. When the > > > firmware loader is built as a module, support for built-in firmware > > > is skipped. This requirement is not really clear to users or even > > > developers. > > > > > > Also, by default the EXTRA_FIRMWARE is always set to an empty string > > > and so by default we really have nothing built-in to that kernel's > > > sections for built-in firmware, so today a all FW_LOADER=y kernels > > > spins their wheels on an empty set of built-in firmware for each > > > firmware request with no true need for it. > > > > > > Add a new kconfig entry to represent built-in firmware support more > > > clearly. This let's knock 3 birds with one stone: > > > > > > o Clarifies that support for built-in firmware requires the > > > firmware loader to be built-in to the kernel > > > > > > o By default we now always skip built-in firmware even if a FW_LOADER=y > > > > > > o This also lets us make it clear that the EXTRA_FIRMWARE_DIR > > > kconfig entry is only used for built-in firmware > > > > > > Reviewed-by: Borislav Petkov > > > Signed-off-by: Luis Chamberlain > > > --- > > > .../driver-api/firmware/built-in-fw.rst | 2 ++ > > > Documentation/x86/microcode.rst | 5 ++-- > > > drivers/base/firmware_loader/Kconfig | 25 +++++++++++++------ > > > drivers/base/firmware_loader/Makefile | 3 +-- > > > drivers/base/firmware_loader/main.c | 4 +-- > > > 5 files changed, 26 insertions(+), 13 deletions(-) > > > > > > diff --git a/Documentation/driver-api/firmware/built-in-fw.rst b/Documentation/driver-api/firmware/built-in-fw.rst > > > index bc1c961bace1..9dd2b1df44f0 100644 > > > --- a/Documentation/driver-api/firmware/built-in-fw.rst > > > +++ b/Documentation/driver-api/firmware/built-in-fw.rst > > > @@ -8,6 +8,7 @@ the filesystem. Instead, firmware can be looked for inside the kernel > > > directly. You can enable built-in firmware using the kernel configuration > > > options: > > > > > > + * CONFIG_FW_LOADER_BUILTIN > > > * CONFIG_EXTRA_FIRMWARE > > > * CONFIG_EXTRA_FIRMWARE_DIR > > > > > > @@ -17,6 +18,7 @@ into the kernel with CONFIG_EXTRA_FIRMWARE: > > > * Speed > > > * Firmware is needed for accessing the boot device, and the user doesn't > > > want to stuff the firmware into the boot initramfs. > > > +* Testing built-in firmware > > > > > > Even if you have these needs there are a few reasons why you may not be > > > able to make use of built-in firmware: > > > diff --git a/Documentation/x86/microcode.rst b/Documentation/x86/microcode.rst > > > index a320d37982ed..d199f0b98869 100644 > > > --- a/Documentation/x86/microcode.rst > > > +++ b/Documentation/x86/microcode.rst > > > @@ -114,11 +114,12 @@ Builtin microcode > > > ================= > > > > > > The loader supports also loading of a builtin microcode supplied through > > > -the regular builtin firmware method CONFIG_EXTRA_FIRMWARE. Only 64-bit is > > > -currently supported. > > > +the regular builtin firmware method using CONFIG_FW_LOADER_BUILTIN and > > > +CONFIG_EXTRA_FIRMWARE. Only 64-bit is currently supported. > > > > > > Here's an example:: > > > > > > + CONFIG_FW_LOADER_BUILTIN=y > > > CONFIG_EXTRA_FIRMWARE="intel-ucode/06-3a-09 amd-ucode/microcode_amd_fam15h.bin" > > > CONFIG_EXTRA_FIRMWARE_DIR="/lib/firmware" > > > > > > diff --git a/drivers/base/firmware_loader/Kconfig b/drivers/base/firmware_loader/Kconfig > > > index 5b24f3959255..de4fcd9d41f3 100644 > > > --- a/drivers/base/firmware_loader/Kconfig > > > +++ b/drivers/base/firmware_loader/Kconfig > > > @@ -29,8 +29,10 @@ if FW_LOADER > > > config FW_LOADER_PAGED_BUF > > > bool > > > > > > -config EXTRA_FIRMWARE > > > - string "Build named firmware blobs into the kernel binary" > > > +config FW_LOADER_BUILTIN > > > + bool "Enable support for built-in firmware" > > > + default n > > > > n is always the default, no need to list it again. > > Oh, alrighty, I'll remove that line. > > > > + depends on FW_LOADER=y > > > > I don't see what this gets us to add another config option. Are you > > making things easier later on? > > This makes a few things clearer for both developers and users. > The code in question is a *feature* *only* when FW_LOADER=y, by > adding a new kconfig to represent this and clearly makeing it > depend on FW_LOADER=y it let's us: > > o Clarify that support for built-in firmware requires > the firmware loader to be built-in to the kernel That is good. > o By default we now always skip built-in firmware even if a FW_LOADER=y I do not understand, why would we ever want to skip built-in firmware? > o This also lets us make it clear that the EXTRA_FIRMWARE_DIR > kconfig entry is only used for built-in firmware How was it ever used for anything else? :) > The above is not easily obvious to developers (including myself when > I was reviewing this code) or users without this new kconfig entry. > > Should I re-send by just removing the one line you asked for? I can not take this as-is, so yes :) thanks, greg k-h