Merge Pull Request from: @guzitao 
 
These patches generally cover the following tasks:

1.optimize kernel cores, remove unused codes, fix compile errors
2.fixes for perf, iommu, kvm, cpufreq, stack trace, ftrace, acpi, selftest, numa, kexec, bpf, kprobe
3.reorganize code structure
4.add C4 support
5.optimize pt_regs structure 
 
Link:https://gitee.com/openeuler/kernel/pulls/15279

 

Reviewed-by: Zhang Jianhua <chris.zjh@huawei.com>
Reviewed-by: Xiongfeng Wang <wangxiongfeng2@huawei.com>
Reviewed-by: Li Nan <linan122@huawei.com>
Signed-off-by: Li Nan <linan122@huawei.com>