x86/perf/zhaoxin: Add stepping check for ZXC

[ Upstream commit fd636b6a9b ]

Some of Nano series processors will lead GP when accessing
PMC fixed counter. Meanwhile, their hardware support for PMC
has not announced externally. So exclude Nano CPUs from ZXC
by checking stepping information. This is an unambiguous way
to differentiate between ZXC and Nano CPUs.

Following are Nano and ZXC FMS information:
Nano FMS: Family=6, Model=F, Stepping=[0-A][C-D]
ZXC FMS:  Family=6, Model=F, Stepping=E-F OR
          Family=6, Model=0x19, Stepping=0-3

Fixes: 3a4ac121c2 ("x86/perf: Add hardware performance events support for Zhaoxin CPU.")

Reported-by: Arjan <8vvbbqzo567a@nospam.xutrox.com>
Reported-by: Kevin Brace <kevinbrace@gmx.com>
Signed-off-by: silviazhao <silviazhao-oc@zhaoxin.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://bugzilla.kernel.org/show_bug.cgi?id=212389
Signed-off-by: Sasha Levin <sashal@kernel.org>
This commit is contained in:
silviazhao 2023-02-08 16:27:22 +08:00 committed by Greg Kroah-Hartman
parent 60892ab8be
commit a9cdc137ea

View file

@ -541,7 +541,13 @@ __init int zhaoxin_pmu_init(void)
switch (boot_cpu_data.x86) {
case 0x06:
if (boot_cpu_data.x86_model == 0x0f || boot_cpu_data.x86_model == 0x19) {
/*
* Support Zhaoxin CPU from ZXC series, exclude Nano series through FMS.
* Nano FMS: Family=6, Model=F, Stepping=[0-A][C-D]
* ZXC FMS: Family=6, Model=F, Stepping=E-F OR Family=6, Model=0x19, Stepping=0-3
*/
if ((boot_cpu_data.x86_model == 0x0f && boot_cpu_data.x86_stepping >= 0x0e) ||
boot_cpu_data.x86_model == 0x19) {
x86_pmu.max_period = x86_pmu.cntval_mask >> 1;