This allows the linker to know that calls to them do not need to switch
TOC and stop errors like the following when linking large configurations:
powerpc64-linux-ld: drivers/built-in.o: In function `.gpiochip_is_requested':
(.text+0x4): sibling call optimization to `_savegpr0_29' does not allow automatic multiple TOCs; recompile with -mminimal-toc or -fno-optimize-sibling-calls, or make `_savegpr0_29' extern
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Gcc 4.5 is now generating out of line register save and restore
in the function prefix and postfix when we use -Os.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
GCC 4.4.x looks to be adding support for generating out-of-line register
saves/restores based on:
http://gcc.gnu.org/ml/gcc-patches/2008-04/msg01678.html
This breaks the kernel if we enable CONFIG_CC_OPTIMIZE_FOR_SIZE. To fix
this we add the use the save/restore code from gcc and simplified it down
for our needs (integer only).
Additionally, we have to link this code into each module. The other
solution was to add EXPORT_SYMBOL() which meant going through the
trampoline which seemed nonsensical for these out-of-line routines.
Finally, we add some checks to prom_init_check.sh to ignore the
out-of-line save/restore functions.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
