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Subject: Re: [PATCH 3/6] perf cs-etm: Save TRCDEVARCH register
To:     Leo Yan <leo.yan@linaro.org>, Mike Leach <mike.leach@linaro.org>
Cc:     Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mathieu Poirier <mathieu.poirier@linaro.org>,
        Coresight ML <coresight@lists.linaro.org>,
        Al Grant <al.grant@arm.com>,
        "Suzuki K. Poulose" <suzuki.poulose@arm.com>,
        Anshuman Khandual <anshuman.khandual@arm.com>,
        John Garry <john.garry@huawei.com>,
        Will Deacon <will@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        linux-arm-kernel <linux-arm-kernel@lists.infradead.org>,
        Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
        linux-perf-users@vger.kernel.org
References: <20210721090706.21523-1-james.clark@arm.com>
 <20210721090706.21523-4-james.clark@arm.com>
 <CAJ9a7Vjz_CMugYrLcAqr_aFsK6jYcqR3xLwJUi9KTXB3aPjnEQ@mail.gmail.com>
 <20210731063731.GC7437@leoy-ThinkPad-X240s>
From:   James Clark <james.clark@arm.com>
Message-ID: <6d1954d2-28bc-4b70-25fc-e74d63cc86cd@arm.com>
Date:   Tue, 3 Aug 2021 13:33:01 +0100
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On 31/07/2021 07:37, Leo Yan wrote:
> I checked ETMv4.3 and ETMv4.4 spec (ARM IHI0064E for ETMv4.3 and ARM
> IHI0064F for ETMv4.4), both clarify ETMv4 has the register TRCDEVARCH;
> thus TRCDEVARCH is not a new register introduced by ETE.
> 
> For this case, it's good to directly add a new field in the metadata
> array for recording register TRCDEVARCH.

This might be true, but the OpenCSD library doesn't take TRCDEVARCH as a config
parameter for ETMv4 so it couldn't be used. This is the struct:

        typedef struct _ocsd_etmv4_cfg 
        {
        uint32_t                reg_idr0;    /**< ID0 register */
        uint32_t                reg_idr1;    /**< ID1 register */
        uint32_t                reg_idr2;    /**< ID2 register */
        uint32_t                reg_idr8;
        uint32_t                reg_idr9;   
        uint32_t                reg_idr10;
        uint32_t                reg_idr11;
        uint32_t                reg_idr12;
        uint32_t                reg_idr13;
        uint32_t                reg_configr;  /**< Config Register */
        uint32_t                reg_traceidr;  /**< Trace Stream ID register */
        ocsd_arch_version_t    arch_ver;   /**< Architecture version */
        ocsd_core_profile_t    core_prof;  /**< Core Profile */
        } ocsd_etmv4_cfg;

And this is ETE where TRCDEVARCH is used:

        typedef struct _ocsd_ete_cfg
        {
        uint32_t                reg_idr0;       /**< ID0 register */
        uint32_t                reg_idr1;       /**< ID1 register */
        uint32_t                reg_idr2;       /**< ID2 register */
        uint32_t                reg_idr8;       /**< ID8 - maxspec */
        uint32_t                reg_devarch;    /**< DevArch register */
        uint32_t                reg_configr;    /**< Config Register */
        uint32_t                reg_traceidr;   /**< Trace Stream ID register */
        ocsd_arch_version_t    arch_ver;        /**< Architecture version */
        ocsd_core_profile_t    core_prof;       /**< Core Profile */
        } ocsd_ete_cfg;

Thanks
James