[Intel-xe] [PATCH] drm/xe/xe_uc_fw: Use firmware files from standard locations

[Lucas De Marchi]

On Wed, Mar 15, 2023 at 07:11:45AM +0100, Mauro Carvalho Chehab wrote:
>On Fri, 10 Mar 2023 09:13:39 +0100
>Mauro Carvalho Chehab <mauro.chehab at linux.intel.com> wrote:
>
>> From: Mauro Carvalho Chehab <mchehab at kernel.org>
>>
>> The GuC/HuC firmware files used by Xe drivers are the same as
>> used by i915. Use the already-known location to find those
>> firmware files, for a couple of reasons:
>>
>> 1. Avoid having the same firmware placed on two different
>>    places on MODULE_FIRMWARE(), if both 915 and xe drivers
>>    are compiled;
>>
>> 2. Having firmware files located on different locations may end
>>    creating bigger initramfs, as the same files will be copied
>>    twice my mkinitrd/dracut/...;
>
>Heh, it turns that it may not even be placing the firmware at the right
>place, if someone does a symlink for /lib/firmware/xe pointing to
>/lib/firmware/i915 (or vice versa), depending on what's implemented
>at the mkinitrd logic.
>
>I found this on /usr/share/initramfs-tools/hook-functions:
>
>        # We don't need to replicate a chain of links completely;
>        # just link directly to the ultimate target
>        link_target="$(readlink -f "${src}")" || return $(($? + 1))
>
>So, basically, using Ubuntu's default mkinitrd package, if
>/lib/firmware/xe is a symlink, instead of storing
>/lib/firmware/xe/bxt_dmc_ver1_07.bin, it will actually store
>/lib/firmware/i915/bxt_dmc_ver1_07.bin at the initramfs, which
>will cause crashes if the Xe driver is not blacklisted.

storing /lib/firmware/i915/bxt_dmc_ver1_07.bin in the initramfs is
actually the correct thing to do as this is what our module is currently
asking for:

	$ modinfo -F firmware build64/drivers/gpu/drm/xe/xe.ko
	xe/tgl_huc_7.9.3.bin
	xe/dg1_huc_7.9.3.bin
	xe/tgl_guc_70.bin
	xe/dg1_guc_70.bin
	xe/dg2_guc_70.bin
	xe/pvc_guc_70.bin
	xe/tgl_guc_70.bin
	xe/adlp_guc_70.bin
	xe/mtl_guc_70.bin
	i915/bxt_dmc_ver1_07.bin
	i915/skl_dmc_ver1_27.bin
	i915/kbl_dmc_ver1_04.bin
	i915/glk_dmc_ver1_04.bin
	i915/icl_dmc_ver1_09.bin
	i915/tgl_dmc_ver2_12.bin
	i915/rkl_dmc_ver2_03.bin
	i915/dg1_dmc_ver2_02.bin
	i915/adls_dmc_ver2_01.bin
	i915/adlp_dmc_ver2_16.bin
	i915/dg2_dmc_ver2_08.bin

And i915 is also using those dmc files.
Note that for this item here, the duplicate firmware blobs (if you also
have i915 built) are the guc/huc ones, not DMC.

I still agree with the change here as it's expected these old platforms
are primarily supported by the i915 driver and we don't need the
firmware files to be in an xe directory.

Lucas De Marchi