Intel: perf/x86: Use event_base_rdpmc for the RDPMC userspace support

mainline inclusion
from mainline-v5.10-rc1
commit 75608cb0
category: feature
bugzilla: https://gitee.com/openeuler/kernel/issues/I47H3V


CVE: NA

--------------------------------

commit 75608cb0 upstream
Backport summary: backport to kernel 4.19.57 for ICX perf topdown support

The RDPMC index is always re-calculated for the RDPMC userspace support,
which is unnecessary.

The RDPMC index value is stored in the variable event_base_rdpmc for
the kernel usage, which can be used for RDPMC userspace support as well.

Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lkml.kernel.org/r/20200723171117.9918-2-kan.liang@linux.intel.com


Signed-off-by: Yunying Sun <yunying.sun@intel.com>
Signed-off-by: Jackie Liu <liuyun01@kylinos.cn>
Signed-off-by: Zheng Zengkai <zhengzengkai@huawei.com>
Reviewed-by: Wei Li <liwei391@huawei.com>
Reviewed-by: Xie XiuQi <xiexiuqi@huawei.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>