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From:   Mike Leach <mike.leach@linaro.org>
Date:   Wed, 7 Jun 2023 11:43:33 +0100
Message-ID: <CAJ9a7VjypLQr3qUA5=BMvvdzS=-eCEjeO7azxK5AKJ4TTM1YSA@mail.gmail.com>
Subject: Re: [PATCH] coresight: etm4x: Match all ETM4 instances based on
 DEVARCH and DEVTYPE
To:     Suzuki K Poulose <suzuki.poulose@arm.com>
Cc:     coresight@lists.linaro.org, linux-arm-kernel@lists.infradead.org,
        linux-kernel@vger.kernel.org,
        Anshuman Khandual <anshuman.khandual@arm.com>,
        Rob Herring <robh+dt@kernel.org>, frowand.list@gmail.com,
        linux@armlinux.org.uk
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On Mon, 5 Jun 2023 at 14:30, Suzuki K Poulose <suzuki.poulose@arm.com> wrote:
>
> Instead of adding the PIDs forever to the list for the new CPUs, let us detect
> a component to be ETMv4 based on the CoreSight CID, DEVTYPE=PE_TRACE and
> DEVARCH=ETMv4. This is already done for some of the ETMs. We can extend the PID
> matching to match the PIDR2:JEDEC, BIT[3], which must be 1 (RA0) always.
>
> Link: https://lkml.kernel.org/r/20230317030501.1811905-1-anshuman.khandual@arm.com
> Cc: Anshuman Khandual <anshuman.khandual@arm.com>
> Cc: Rob Herring <robh+dt@kernel.org>
> Cc: frowand.list@gmail.com
> Cc: linux@armlinux.org.uk
> Cc: Mike Leach <mike.leach@linaro.org>
> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
> ---
>  .../coresight/coresight-etm4x-core.c          |  5 +++++
>  drivers/hwtracing/coresight/coresight-priv.h  | 19 +++++++++++++++++--
>  2 files changed, 22 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/hwtracing/coresight/coresight-etm4x-core.c b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> index 4c15fae534f3..8a2e24d5686a 100644
> --- a/drivers/hwtracing/coresight/coresight-etm4x-core.c
> +++ b/drivers/hwtracing/coresight/coresight-etm4x-core.c
> @@ -2260,6 +2260,11 @@ static const struct amba_id etm4_ids[] = {
>         CS_AMBA_UCI_ID(0x000cc0af, uci_id_etm4),/* Marvell ThunderX2 */
>         CS_AMBA_UCI_ID(0x000b6d01, uci_id_etm4),/* HiSilicon-Hip08 */
>         CS_AMBA_UCI_ID(0x000b6d02, uci_id_etm4),/* HiSilicon-Hip09 */
> +       /*
> +        * Match all PIDs with ETM4 DEVARCH. No need for adding any of the new
> +        * CPUs to the list here.
> +        */
> +       CS_AMBA_MATCH_ALL_UCI(uci_id_etm4),
>         {},
>  };
>
> diff --git a/drivers/hwtracing/coresight/coresight-priv.h b/drivers/hwtracing/coresight/coresight-priv.h
> index 595ce5862056..72ec36c9232c 100644
> --- a/drivers/hwtracing/coresight/coresight-priv.h
> +++ b/drivers/hwtracing/coresight/coresight-priv.h
> @@ -193,12 +193,27 @@ extern void coresight_remove_cti_ops(void);
>         }
>
>  /* coresight AMBA ID, full UCI structure: id table entry. */
> -#define CS_AMBA_UCI_ID(pid, uci_ptr)           \
> +#define __CS_AMBA_UCI_ID(pid, m, uci_ptr)      \
>         {                                       \
>                 .id     = pid,                  \
> -               .mask   = 0x000fffff,           \
> +               .mask   = m,                    \
>                 .data   = (void *)uci_ptr       \
>         }
> +#define CS_AMBA_UCI_ID(pid, uci)       __CS_AMBA_UCI_ID(pid, 0x000fffff, uci)
> +/*
> + * PIDR2[JEDEC], BIT(3) must be 1 (Read As One) to indicate that rest of the
> + * PIDR1, PIDR2 DES_* fields follow JEDEC encoding for the designer. Use that
> + * as a match value for blanket matching all devices in the given CoreSight
> + * device type and architecture.
> + */
> +#define PIDR2_JEDEC                    BIT(3)
> +#define PID_PIDR2_JEDEC                        (PIDR2_JEDEC << 16)
> +/*
> + * Match all PIDs in a given CoreSight device type and architecture, defined
> + * by the uci.
> + */
> +#define CS_AMBA_MATCH_ALL_UCI(uci)                                     \
> +       __CS_AMBA_UCI_ID(PID_PIDR2_JEDEC, PID_PIDR2_JEDEC, uci)
>
>  /* extract the data value from a UCI structure given amba_id pointer. */
>  static inline void *coresight_get_uci_data(const struct amba_id *id)
> --
> 2.34.1
>
Reviewed by:- Mike Leach <mike.leach@linaro.org>

-- 
Mike Leach
Principal Engineer, ARM Ltd.
Manchester Design Centre. UK