# git rev-parse -q --verify 5f60bb2254dec0233f5190a51b35bb5a2688de94^{commit}
# git fetch -q -n -f git://gitlab.ozlabs.ibm.com/mirror/linux-npiggin.git kerkins
# git rev-parse -q --verify 5f60bb2254dec0233f5190a51b35bb5a2688de94^{commit}
5f60bb2254dec0233f5190a51b35bb5a2688de94
# git checkout -q -f -B kisskb 5f60bb2254dec0233f5190a51b35bb5a2688de94
# git clean -qxdf
# < git log -1
# commit 5f60bb2254dec0233f5190a51b35bb5a2688de94
# Author: Nicholas Piggin <npiggin@gmail.com>
# Date:   Fri Sep 13 22:07:01 2019 +1000
# 
#     powerpc/64s: system call support for scv/rfscv instructions
#     
#     Add support for the scv instruction on POWER9 and later CPUs.
#     
#     For now this implements the zeroth scv vector 'scv 0', as identical
#     to 'sc' system calls, with the exception that lr is not preserved, and
#     it is 64-bit only. There may yet be changes made to this ABI, so it's
#     for testing only.
#     
#     rfscv is implemented to return from scv type system calls. It can not
#     be used to return from sc system calls because those are defined to
#     preserve lr.
#     
#     In a comparison of getpid syscall, the test program had scv taking
#     about 3 more cycles in user mode (92 vs 89 for sc), due to lr handling.
#     getpid syscall throughput on POWER9 is improved by 33%, mostly due to
#     reducing mtmsr and mtspr.
#     
#     Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version
# < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version
# < git log --format=%s --max-count=1 5f60bb2254dec0233f5190a51b35bb5a2688de94
# < make -s -j 160 ARCH=powerpc O=/kisskb/build/npiggin_ppc64le_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  ppc64le_defconfig
# < make -s -j 160 ARCH=powerpc O=/kisskb/build/npiggin_ppc64le_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  help
# make -s -j 160 ARCH=powerpc O=/kisskb/build/npiggin_ppc64le_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  olddefconfig
# make -s -j 160 ARCH=powerpc O=/kisskb/build/npiggin_ppc64le_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
WARNING: vmlinux.o(.text+0x4820): Section mismatch in reference from the variable __boot_from_prom to the function .init.text:prom_init()
The function __boot_from_prom() references
the function __init prom_init().
This is often because __boot_from_prom lacks a __init 
annotation or the annotation of prom_init is wrong.

WARNING: vmlinux.o(.text+0x49c8): Section mismatch in reference from the variable start_here_common to the function .init.text:start_kernel()
The function start_here_common() references
the function __init start_kernel().
This is often because start_here_common lacks a __init 
annotation or the annotation of start_kernel is wrong.

Completed OK
# rm -rf /kisskb/build/npiggin_ppc64le_defconfig_powerpc-gcc5
# Build took: 0:01:04.862610