Re: [PATCH v10 09/24] coresight: etm3x: allow etm3x to be built as a module

From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: Tingwei Zhang <tingweiz@codeaurora.org>
Cc: tsoni@codeaurora.org, saiprakash.ranjan@codeaurora.org,
	kim.phillips@arm.com, Suzuki K Poulose <suzuki.poulose@arm.com>,
	alexander.shishkin@linux.intel.com, gregkh@linuxfoundation.org,
	coresight@lists.linaro.org, jinlmao@codeaurora.org,
	ykaukab@suse.de, linux@armlinux.org.uk,
	linux-kernel@vger.kernel.org, rdunlap@infradead.org,
	tingwei@codeaurora.org, leo.yan@linaro.org,
	linux-arm-kernel@lists.infradead.org, mike.leach@linaro.org
Subject: Re: [PATCH v10 09/24] coresight: etm3x: allow etm3x to be built as a module
Date: Mon, 14 Sep 2020 09:45:13 -0600	[thread overview]
Message-ID: <20200914154513.GA3238264@xps15> (raw)
In-Reply-To: <20200914021927.GB22686@codeaurora.org>

On Mon, Sep 14, 2020 at 10:19:28AM +0800, Tingwei Zhang wrote:
> On Sun, Sep 13, 2020 at 09:17:05PM +0800, Suzuki K Poulose wrote:
> > On 08/21/2020 04:44 AM, Tingwei Zhang wrote:
> > >From: Kim Phillips <kim.phillips@arm.com>
> > >
> > >Allow to build coresight-etm3x as a module, for ease of development.
> > >
> > >- Kconfig becomes a tristate, to allow =m
> > >- append -core to source file name to allow module to
> > >   be called coresight-etm3x by the Makefile
> > >- add an etm_remove function, for module unload
> > >- add a MODULE_DEVICE_TABLE for autoloading on boot
> > >
> > >Cc: Mathieu Poirier <mathieu.poirier@linaro.org>
> > >Cc: Leo Yan <leo.yan@linaro.org>
> > >Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
> > >Cc: Randy Dunlap <rdunlap@infradead.org>
> > >Cc: Suzuki K Poulose <Suzuki.Poulose@arm.com>
> > >Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
> > >Cc: Russell King <linux@armlinux.org.uk>
> > >Signed-off-by: Kim Phillips <kim.phillips@arm.com>
> > >Signed-off-by: Tingwei Zhang <tingwei@codeaurora.org>
> > >Reviewed-by: Mike Leach <mike.leach@linaro.org>
> > 
> > 
> > >diff --git a/drivers/hwtracing/coresight/coresight-etm3x.c
> > b/drivers/hwtracing/coresight/coresight-etm3x-core.c
> > >similarity index 97%
> > >rename from drivers/hwtracing/coresight/coresight-etm3x.c
> > >rename to drivers/hwtracing/coresight/coresight-etm3x-core.c
> > >index bf22dcfd3327..ba9c86497acb 100644
> > >--- a/drivers/hwtracing/coresight/coresight-etm3x.c
> > >+++ b/drivers/hwtracing/coresight/coresight-etm3x-core.c
> > >@@ -895,6 +895,23 @@ static int etm_probe(struct amba_device *adev,
> > const struct amba_id *id)
> > >  	return ret;
> > >  }
> > >+static int __exit etm_remove(struct amba_device *adev)
> > >+{
> > >+	struct etm_drvdata *drvdata = dev_get_drvdata(&adev->dev);
> > >+
> > >+	etm_perf_symlink(drvdata->csdev, false);
> > >+
> > >+	if (--etm_count == 0) {
> > >+
> > cpuhp_remove_state_nocalls(CPUHP_AP_ARM_CORESIGHT_STARTING);
> > >+		if (hp_online)
> > >+			cpuhp_remove_state_nocalls(hp_online);
> > >+	}
> > >+
> > >+	coresight_unregister(drvdata->csdev);
> > >+
> > >+	return 0;
> > >+}
> > >+
> > 
> > Don't we need to fix the races like we did for ETMv4 ?
> > 
> > Suzuki
> > 
> Yes, we need that.  Unfortunately, I don't have ETMv3 devie to verify the
> change.  Mathieu has been very kind to offer his help to take care of
> ETMv3.

Correct - I will do the testing but the implementation still has to come from
you.

> 
> Thanks,
> Tingwei
> > _______________________________________________
> > linux-arm-kernel mailing list
> > linux-arm-kernel@lists.infradead.org
> > http://lists.infradead.org/mailman/listinfo/linux-arm-kernel

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