Re: [PATCH v3] powerpc: Add gpr1 and fpu save/restore functions

----- Original Message -----

From: "christophe leroy" <redacted>
To: "Timothy Pearson" <tpearson@raptorengineering.com>
Cc: "linuxppc-dev" <redacted>
Sent: Saturday, February 17, 2024 10:39:06 AM
Subject: Re: [PATCH v3] powerpc: Add gpr1 and fpu save/restore functions

Le 16/02/2024 à 18:24, Timothy Pearson a écrit :

quoted

When building the kernel in size optimized mode with the amdgpu module enabled,
gcc will begin referencing external gpr1 and fpu save/restore functions.  This
will then cause a linker failure as we do not link against libgcc which
normally contains those builtin functions.

Right, but modules are linked with --save-restore-funcs when using gcc
so crtsavres.o is not used and only your change to scripts/mod/modpost.c
seems to be required to be able to build amdgpu module with GCC.

Maybe that's different with clang, but maybe worth a test and then a
second patch ?

It looks to be gated on ld, specifically if we're CONFIG_PPC64 && CONFIG_LD_IS_BFD.  I can update the patch to match that gate if desired.

Nevertheless, see comments below, you can do even shorter and more
readable using GAS macros.

That's true, but my goal was to get this working, not refactor the entire file. :)  Any chance we can merge and do a fine polish later, especially if there's a distinct possibility of the entire file going away in the near future?