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9c9b4ad24b
Currently, all bits in mcountern are enabled unconditionally at boot time. With SBI PMU extension, all the programmable counters should enabled only during performance monitoring for a particular event. However, this is done only if mcountinhibit is implemented because the supervisor mode can not start/stop any event without mcountinhibit. Similarly, supervisor should take care enabling scounteren which allows U-mode to access programmable pmu counters. All the non-programmable ones (CY, TM, IR) should be enabled in M-mode because some userspace may rely on builtins such as __builtin_readcyclecounter. Supervisor OS can still disable them during initial configuration. Reviewed-by: Anup Patel <anup.patel@wdc.com> Signed-off-by: Atish Patra <atish.patra@wdc.com>