From: Suzuki K Poulose <suzuki.poulose@arm.com>
To: Mathieu Poirier <mathieu.poirier@linaro.org>
Cc: anshuman.khandual@arm.com, catalin.marinas@arm.com,
coresight@lists.linaro.org, linux-kernel@vger.kernel.org,
jonathan.zhouwen@huawei.com, leo.yan@linaro.org,
linux-arm-kernel@lists.infradead.org, mike.leach@linaro.org
Subject: Re: [PATCH v7 00/28] coresight: etm4x: Support for system instructions
Date: Mon, 25 Jan 2021 22:05:12 +0000 [thread overview]
Message-ID: <4f1171f1-8d3c-cba7-ac5c-d88264e959bc@arm.com> (raw)
In-Reply-To: <20210125184950.GC894394@xps15>
On 1/25/21 6:49 PM, Mathieu Poirier wrote:
> On Sun, Jan 10, 2021 at 10:48:22PM +0000, Suzuki K Poulose wrote:
>> CoreSight ETMv4.4 obsoletes memory mapped access to ETM and
>> mandates the system instructions for registers.
>> This also implies that they may not be on the amba bus.
>> Right now all the CoreSight components are accessed via memory
>> map. Also, we have some common routines in coresight generic
>> code driver (e.g, CS_LOCK, claim/disclaim), which assume the
>> mmio. In order to preserve the generic algorithms at a single
>> place and to allow dynamic switch for ETMs, this series introduces
>> an abstraction layer for accessing a coresight device. It is
>> designed such that the mmio access are fast tracked (i.e, without
>> an indirect function call).
>>
>> This will also help us to get rid of the driver+attribute specific
>> sysfs show/store routines and replace them with a single routine
>> to access a given register offset (which can be embedded in the
>> dev_ext_attribute). This is not currently implemented in the series,
>> but can be achieved.
>>
>> Further we switch the generic routines to work with the abstraction.
>> With this in place, we refactor the etm4x code a bit to allow for
>> supporting the system instructions with very little new code.
>>
>> We use TRCDEVARCH for the detection of the ETM component, which
>> is a standard register as per CoreSight architecture, rather than
>> the etm specific id register TRCIDR1. This is for making sure
>> that we are able to detect the ETM via system instructions accurately,
>> when the the trace unit could be anything (etm or a custom trace unit).
>> To keep the backward compatibility for any existing broken
>> impelementation which may not implement TRCDEVARCH, we fall back to TRCIDR1.
>> Also this covers us for the changes in the future architecture [0].
>>
>> Also, v8.4 self-hosted tracing extensions (coupled with ETMv4.4) adds
>> new filtering registers for trace by exception level. So on a v8.4
>> system, with Trace Filtering support, without the appropriate
>> programming of the Trace filter registers (TRFCR_ELx), tracing
>> will not be enabled. This series also includes the TraceFiltering
>> support to cover the ETM-v4.4 support.
>>
>> The series has been mildly tested on a model for system instructions.
>> I would really appreciate any testing on real hardware.
>>
>> Applies on coresight/next. A tree is available here [1].
>
> I have applied this set.
Thanks Mathieu, appreciate it.
Cheers
Suzuki
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prev parent reply other threads:[~2021-01-25 22:06 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-10 22:48 [PATCH v7 00/28] coresight: etm4x: Support for system instructions Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 01/28] coresight: etm4x: Handle access to TRCSSPCICRn Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 02/28] coresight: etm4x: Skip accessing TRCPDCR in save/restore Suzuki K Poulose
2021-01-25 18:39 ` Mathieu Poirier
2021-01-10 22:48 ` [PATCH v7 03/28] coresight: Introduce device access abstraction Suzuki K Poulose
2021-01-25 18:42 ` Mathieu Poirier
2021-01-10 22:48 ` [PATCH v7 04/28] coresight: tpiu: Prepare for using coresight " Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 05/28] coresight: Convert coresight_timeout to use " Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 06/28] coresight: Convert claim/disclaim operations to use access wrappers Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 07/28] coresight: etm4x: Always read the registers on the host CPU Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 08/28] coresight: etm4x: Convert all register accesses Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 09/28] coresight: etm4x: Make offset available for sysfs attributes Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 10/28] coresight: etm4x: Add commentary on the registers Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 11/28] coresight: etm4x: Add sysreg access helpers Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 12/28] coresight: etm4x: Hide sysfs attributes for unavailable registers Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 13/28] coresight: etm4x: Define DEVARCH register fields Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 14/28] coresight: etm4x: Check for Software Lock Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 15/28] coresight: etm4x: Cleanup secure exception level masks Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 16/28] coresight: etm4x: Clean up " Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 17/28] coresight: etm4x: Handle ETM architecture version Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 18/28] coresight: etm4x: Detect access early on the target CPU Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 19/28] coresight: etm4x: Use TRCDEVARCH for component discovery Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 20/28] coresight: etm4x: Expose trcdevarch via sysfs Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 21/28] coresight: etm4x: Add necessary synchronization for sysreg access Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 22/28] coresight: etm4x: Detect system instructions support Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 23/28] coresight: etm4x: Refactor probing routine Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 24/28] coresight: etm4x: Run arch feature detection on the CPU Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 25/28] coresight: etm4x: Add support for sysreg only devices Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 26/28] dts: bindings: coresight: ETM system register access only units Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 27/28] arm64: Add TRFCR_ELx definitions Suzuki K Poulose
2021-01-10 22:48 ` [PATCH v7 28/28] coresight: Add support for v8.4 SelfHosted tracing Suzuki K Poulose
2021-02-12 10:34 ` Mike Leach
2021-02-12 15:36 ` Suzuki K Poulose
2021-02-12 17:30 ` Mike Leach
2021-02-18 14:51 ` Suzuki K Poulose
2021-01-25 18:49 ` [PATCH v7 00/28] coresight: etm4x: Support for system instructions Mathieu Poirier
2021-01-25 22:05 ` Suzuki K Poulose [this message]
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