[PATCH v2 1/6] powerpc: Add hardware description string

[Nathan Lynch]

Michael Ellerman <mpe at ellerman.id.au> writes:
> Create a hardware description string, which we will use to record
> various details of the hardware platform we are running on.
>
> Print the accumulated description at boot, and use it to set the generic
> description which is printed in oopses.
>
> To begin with add ppc_md.name, aka the "machine description".
>
> Example output at boot with the full series applied:
>
>   Linux version 6.0.0-rc2-gcc-11.1.0-00199-g893f9007a5ce-dirty (michael at alpine1-p1) (powerpc64-linux-gcc (GCC) 11.1.0, GNU ld (GNU Binutils) 2.36.1) #844 SMP Thu Sep 29 22:29:53 AEST 2022
>   Hardware name: model:'IBM pSeries (emulated by qemu)' cpu:'POWER8 (raw)' pvr:0x4d0200 lpvr:0xf000004 of:'SLOF,HEAD' machine:pSeries
>   printk: bootconsole [udbg0] enabled
>
> Signed-off-by: Michael Ellerman <mpe at ellerman.id.au>
> ---
>  arch/powerpc/include/asm/setup.h   |  2 ++
>  arch/powerpc/kernel/setup-common.c | 19 ++++++++++++++++++-
>  2 files changed, 20 insertions(+), 1 deletion(-)
>
> v2: Print the string at boot as suggested by Nathan.

Thanks!

I've booted the series on P8 and P9 LPARs:

Hardware name: model:'IBM,8408-E8E' cpu:'POWER8E (raw)' pvr:0x4b0201 lpvr:0xf000004 of:'IBM,FW860.50 (SV860_146)' hv:'phyp' machine:pSeries

Hardware name: model:'IBM,9040-MR9' cpu:'POWER9 (raw)' pvr:0x4e2102 lpvr:0xf000005 of:'IBM,FW950.01 (VM950_047)' hv:'phyp' machine:pSeries

Not on objection but just an FYI: we're already very close to exceeding
the arch description buffer's size on PowerVM. Both of the above are
over 120 bytes.

It also occurs to me that we'll want to rebuild the arch description
string after partition migration. Probably immediately after processing
the device tree updates.

Regardless, LGTM.