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

From: Mathieu Poirier <mathieu.poirier@linaro.org>
To: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: tingwei@codeaurora.org, alexander.shishkin@linux.intel.com,
	mike.leach@linaro.org, kim.phillips@arm.com,
	gregkh@linuxfoundation.org, leo.yan@linaro.org,
	rdunlap@infradead.org, linux@armlinux.org.uk, ykaukab@suse.de,
	tsoni@codeaurora.org, saiprakash.ranjan@codeaurora.org,
	jinlmao@codeaurora.org, coresight@lists.linaro.org,
	linux-arm-kernel@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH v10 09/24] coresight: etm3x: allow etm3x to be built as a module
Date: Mon, 14 Sep 2020 12:11:40 -0600	[thread overview]
Message-ID: <20200914181140.GD3238264@xps15> (raw)
In-Reply-To: <0c2abd02-4fe6-5eaa-e9d3-41811f062ac1@arm.com>

On Sun, Sep 13, 2020 at 02:17:05PM +0100, 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 ?

This is one of the things I wanted to get back to but Suzuki beat me to it.

I am now done reviewing this set.

Thanks,
Mathieu

> 
> Suzuki