Re: [PATCH V3 1/7] arm64/perf: Add BRBE registers and fields

From: Mark Brown
Date: Thu Sep 29 2022 - 07:29:53 EST


On Thu, Sep 29, 2022 at 01:28:51PM +0530, Anshuman Khandual wrote:

Thanks for doing this work - I did spot a few small issues though.

> /* id_aa64dfr0 */
> +#define ID_AA64DFR0_BRBE_SHIFT 52
> #define ID_AA64DFR0_MTPMU_SHIFT 48
> #define ID_AA64DFR0_TRBE_SHIFT 44
> #define ID_AA64DFR0_TRACE_FILT_SHIFT 40
> @@ -848,6 +952,9 @@
> #define ID_AA64DFR0_PMSVER_8_2 0x1
> #define ID_AA64DFR0_PMSVER_8_3 0x2
>
> +#define ID_AA64DFR0_BRBE 0x1
> +#define ID_AA64DFR0_BRBE_V1P1 0x2
> +
> #define ID_DFR0_PERFMON_SHIFT 24
>
> #define ID_DFR0_PERFMON_8_0 0x3

This is already done in -next as a result of ID_AA64DFR0_EL1 being
converted, the enumberation define comes out as
ID_AA64DFR0_EL1_BRBE_BRBE_V1P1.

> +# This is just a dummy register declaration to get all common field masks and
> +# shifts for accessing given BRBINF contents.
> +Sysreg BRBINF_EL1 2 1 8 0 0
> +Res0 63:47
> +Field 46 CCU
> +Field 45:32 CC
> +Res0 31:18
> +Field 17 LASTFAILED
> +Field 16 TX

According to DDI0487I.a bit 16 is called T not TX.

> +Res0 15:14
> +Enum 13:8 TYPE

It's probably worth noting in the comment the issue with Enums here
that's meaning you're not using a SysregFields - I'm not sure what
people will think of this but providing a definition using the ID for
the 0th register does seem expedient.

> +Enum 7:6 EL
> + 0b00 EL0
> + 0b01 EL1
> + 0b10 EL2
> +EndEnum

According to DDI0487I.a 0b11 has the value EL3 (when FEAT_BRBEv1p1).

> +Sysreg BRBCR_EL1 2 1 9 0 0
> +Res0 63:24
> +Field 23 EXCEPTION
> +Field 22 ERTN
> +Res0 21:9
> +Field 8 FZP
> +Field 7 ZERO

According to DDI0487I.a bit 7 is Res0.

> +Field 2 ZERO1

According to DDI0487I.a bit 2 is Res0.

> +Sysreg BRBFCR_EL1 2 1 9 0 1

> +Field 16 ENL

Accoding to DDI0487I.a this is EnI (ie, an L not an I).

> +Sysreg BRBINFINJ_EL1 2 1 9 1 0

> +Field 16 TX

According to DDI0487I.a this is T not TX.

> +Enum 7:6 EL
> + 0b00 EL0
> + 0b01 EL1
> + 0b10 EL2
> +EndEnum

According to DDI0487I.a 0b11 has the value EL3 (when FEAT_BRBEv1p1).

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