linux_dsm_epyc7002/arch
Michael Ellerman 6eeb9b3b9c powerpc/64s: Fix section mismatch warnings from boot code
We currently have two section mismatch warnings:

  The function __boot_from_prom() references
  the function __init prom_init().

  The function start_here_common() references
  the function __init start_kernel().

The warnings are correct, we do have branches from non-init code into
init code, which is freed after boot. But we don't expect to ever
execute any of that early boot code after boot, if we did that would
be a bug. In particular calling into OF after boot would be fatal
because OF is no longer resident.

So for now fix the warnings by marking the relevant functions as
__REF, which puts them in the ".ref.text" section.

This causes some reordering of the functions in the final link:

  @@ -217,10 +217,9 @@
   c00000000000b088 t generic_secondary_common_init
   c00000000000b124 t __mmu_off
   c00000000000b14c t __start_initialization_multiplatform
  -c00000000000b1ac t __boot_from_prom
  -c00000000000b1ec t __after_prom_start
  -c00000000000b260 t p_end
  -c00000000000b27c T copy_and_flush
  +c00000000000b1ac t __after_prom_start
  +c00000000000b220 t p_end
  +c00000000000b23c T copy_and_flush
   c00000000000b300 T __secondary_start
   c00000000000b300 t copy_to_here
   c00000000000b344 t start_secondary_prolog
  @@ -228,8 +227,9 @@
   c00000000000b36c t enable_64b_mode
   c00000000000b388 T relative_toc
   c00000000000b3a8 t p_toc
  -c00000000000b3b0 t start_here_common
  -c00000000000b3d0 t start_here_multiplatform
  +c00000000000b3b0 t __boot_from_prom
  +c00000000000b3f0 t start_here_multiplatform
  +c00000000000b480 t start_here_common
   c00000000000b880 T system_call_common
   c00000000000b974 t system_call
   c00000000000b9dc t system_call_exit

In particular __boot_from_prom moves after copy_to_here, which means
it's not copied to zero in the first stage of copy of the kernel to
zero.

But that's OK, because we only call __boot_from_prom before we do the
copy, so it makes no difference when it's copied. The call sequence
is:
  __start
  -> __start_initialization_multiplatform
     -> __boot_from_prom
        -> __start
           -> __start_initialization_multiplatform
              -> __after_prom_start
                 -> copy_and_flush
                 -> copy_and_flush (relocated to 0)
                    -> start_here_multiplatform
                       -> early_setup

Reported-by: Mauricio Faria de Oliveira <mauricfo@linux.ibm.com>
Reported-by: Roman Bolshakov <r.bolshakov@yadro.com>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200225031328.14676-1-mpe@ellerman.id.au
2020-03-25 12:07:59 +11:00
..
alpha Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
arc arc: mm: add p?d_leaf() definitions 2020-02-04 03:05:24 +00:00
arm ARM: SoC fixes 2020-02-15 13:16:47 -08:00
arm64 ARM: SoC fixes 2020-02-15 13:16:47 -08:00
c6x Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-28 10:07:09 -08:00
csky Microblaze patches for 5.6-rc1 2020-02-04 11:58:07 +00:00
h8300 Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-28 10:07:09 -08:00
hexagon Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2020-01-28 10:07:09 -08:00
ia64 proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
m68k Merge branch 'for-next' of git://git.kernel.org/pub/scm/linux/kernel/git/gerg/m68knommu 2020-02-06 08:13:23 +00:00
microblaze Microblaze patches for 5.6-rc1 2020-02-04 11:58:07 +00:00
mips Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
nds32 TTY/Serial driver updates for 5.6-rc1 2020-01-29 10:13:27 -08:00
nios2 TTY/Serial driver updates for 5.6-rc1 2020-01-29 10:13:27 -08:00
openrisc TTY/Serial driver updates for 5.6-rc1 2020-01-29 10:13:27 -08:00
parisc Merge branch 'parisc-5.6-1' of git://git.kernel.org/pub/scm/linux/kernel/git/deller/parisc-linux 2020-02-05 07:29:40 +00:00
powerpc powerpc/64s: Fix section mismatch warnings from boot code 2020-03-25 12:07:59 +11:00
riscv Microblaze patches for 5.6-rc1 2020-02-04 11:58:07 +00:00
s390 s390/time: Fix clk type in get_tod_clock 2020-02-11 20:15:42 +01:00
sh proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
sparc Kbuild updates for v5.6 (2nd) 2020-02-09 16:05:50 -08:00
um proc: convert everything to "struct proc_ops" 2020-02-04 03:05:26 +00:00
unicore32 MPX requires recompiling applications, which requires compiler support. 2020-01-30 16:11:50 -08:00
x86 Bugfixes and improvements to selftests. On top of this, Mauro converted the 2020-02-16 13:01:42 -08:00
xtensa Xtensa updates for v5.6: 2020-02-07 12:22:29 -08:00
.gitignore
Kconfig asm-generic/tlb: provide MMU_GATHER_TABLE_FREE 2020-02-04 03:05:26 +00:00