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 DC631C433F5 for ; Mon, 11 Oct 2021 17:35:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id BAC8A60EB1 for ; Mon, 11 Oct 2021 17:35:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231942AbhJKRhv (ORCPT ); Mon, 11 Oct 2021 13:37:51 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59970 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231156AbhJKRhv (ORCPT ); Mon, 11 Oct 2021 13:37:51 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 15B85C061570; Mon, 11 Oct 2021 10:35:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20210309; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description; bh=I6yZ9zx7B4CxK1FcMbBf4dNiqFWQUDhjJKBNKLinZKc=; b=WgW+i+lRiYG5w3GNHZdDYgD3h1 F7nq9T466tF0JFQMZxMvZQ5jMMkU1eR/NTRFGdIMYZvoIEov/A2Cm5VcbYz1tgt7fII1FtBj6VpJm rysGbQJJWCPtiYCZLNqqeOAUKkF94GThwcjuFNOFXMPvCr2Toa1L5xhKY79+h+r5UPBlibjMe8j2E svViCRTvnFmkM7iyiLK/ab3RzEsY1F6ZwvawjmK9ljM6EPnjYgxckX+J7cRowQaAYo4vnZ+g7QZdG /Ek4B15RNLd6B0kqiK3irCZ3i3+eme7zVH8glMdZxdTbKgd/G6k4uS87PkAL+MjLJ06fxwExdYNYH 6BuPO3hg==; Received: from mcgrof by bombadil.infradead.org with local (Exim 4.94.2 #2 (Red Hat Linux)) id 1mZzD7-00AFE9-DQ; Mon, 11 Oct 2021 17:35:37 +0000 Date: Mon, 11 Oct 2021 10:35:37 -0700 From: Luis Chamberlain To: Greg KH 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: Sender: Luis Chamberlain Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org 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 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 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? Luis