Messages in this thread Patch in this message | | | From | Cody Yao-oc <> | Subject | [PATCH] x86/perf: Fixed kernel panic during boot on Nano processor. | Date | Mon, 7 Jun 2021 09:31:09 +0800 |
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From: CodyYao-oc <CodyYao-oc@zhaoxin.com>
Nano processor may not fully support rdpmc instruction, it works well for reading general pmc counter, but will lead to GP(general protection) when accessing fixed pmc counter. Futhermore, family/model information is same between Nano processor and ZX-C processor, it leads to zhaoxin pmu driver is wrongly loaded for Nano processor, which resulting boot kernal fail.
To solve this problem, stepping information will be checked to distinguish between Nano processor and ZX-C processor.
[https://bugzilla.kernel.org/show_bug.cgi?id=212389]
Reported-by: Arjan <8vvbbqzo567a@nospam.xutrox.com> Signed-off-by: CodyYao-oc <CodyYao-oc@zhaoxin.com> --- arch/x86/events/zhaoxin/core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/arch/x86/events/zhaoxin/core.c b/arch/x86/events/zhaoxin/core.c index 949d845c922b..cef1de251613 100644 --- a/arch/x86/events/zhaoxin/core.c +++ b/arch/x86/events/zhaoxin/core.c @@ -541,7 +541,8 @@ __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) { + 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; -- 2.17.1
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