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 <mcgrof@xxxxxxxxxx> > > > > > > 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 <bp@xxxxxxx> > > > Signed-off-by: Luis Chamberlain <mcgrof@xxxxxxxxxx> > > > --- > > > .../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
