Pull arch/csky updates from Guo Ren:
"Here are three main features (cpu_hotplug, basic ftrace, basic perf)
and some bugfixes:
Features:
- Add CPU-hotplug support for SMP
- Add ftrace with function trace and function graph trace
- Add Perf support
- Add EM_CSKY_OLD 39
- optimize kernel panic print.
- remove syscall_exit_work
Bugfixes:
- fix abiv2 mmap(... O_SYNC) failure
- fix gdb coredump error
- remove vdsp implement for kernel
- fix qemu failure to bootup sometimes
- fix ftrace call-graph panic
- fix device tree node reference leak
- remove meaningless header-y
- fix save hi,lo,dspcr regs in switch_stack
- remove unused members in processor.h"
* tag 'csky-for-linus-4.21' of git://github.com/c-sky/csky-linux:
csky: Add perf support for C-SKY
csky: Add EM_CSKY_OLD 39
clocksource/drivers/c-sky: fixup ftrace call-graph panic
csky: ftrace call graph supported.
csky: basic ftrace supported
csky: remove unused members in processor.h
csky: optimize kernel panic print.
csky: stacktrace supported.
csky: CPU-hotplug supported for SMP
clocksource/drivers/c-sky: fixup qemu fail to bootup sometimes.
csky: fixup save hi,lo,dspcr regs in switch_stack.
csky: remove syscall_exit_work
csky: fixup remove vdsp implement for kernel.
csky: bugfix gdb coredump error.
csky: fixup abiv2 mmap(... O_SYNC) failed.
csky: define syscall_get_arch()
elf-em.h: add EM_CSKY
csky: remove meaningless header-y
csky: Don't leak device tree node reference