Re: [PATCH 01/15] drm/i915/guc: Tidy guc_log_control

[Sagar Arun Kamble <sagar.a.kamble@intel.com>]

On 3/2/2018 5:22 PM, Michał Winiarski wrote:
> On Fri, Mar 02, 2018 at 04:39:38PM +0530, Sagar Arun Kamble wrote:
>>
>> On 2/27/2018 6:22 PM, Michał Winiarski wrote:
>>> We plan to decouple log runtime (mapping + relay) from verbosity control.
>>> Let's tidy the code now to reduce the churn in the following patches.
>>>
>>> Signed-off-by: Michał Winiarski <michal.winiarski@intel.com>
>>> Cc: Chris Wilson <chris@chris-wilson.co.uk>
>>> Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
>>> Cc: Michal Wajdeczko <michal.wajdeczko@intel.com>
>>> Cc: Sagar Arun Kamble <sagar.a.kamble@intel.com>
>>> ---
>>>    drivers/gpu/drm/i915/i915_debugfs.c  | 11 ++----
>>>    drivers/gpu/drm/i915/intel_guc_log.c | 75 +++++++++++++++++++-----------------
>>>    drivers/gpu/drm/i915/intel_guc_log.h |  3 +-
>>>    3 files changed, 46 insertions(+), 43 deletions(-)
>>>
>>> diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
>>> index 33fbf3965309..58983cafaece 100644
>>> --- a/drivers/gpu/drm/i915/i915_debugfs.c
>>> +++ b/drivers/gpu/drm/i915/i915_debugfs.c
>>> @@ -2500,13 +2500,10 @@ static int i915_guc_log_control_get(void *data, u64 *val)
>> Should we name this i915_guc_log_level_get instead? and other related
>> functions too?
> I chose symmetry here, note that the debugfs file is still named
> i915_guc_log_control at this point. This changes later in the series though.
>
>>>    {
>>>    	struct drm_i915_private *dev_priv = data;
>>> -	if (!HAS_GUC(dev_priv))
>>> +	if (!USES_GUC(dev_priv))
>>>    		return -ENODEV;
>>> -	if (!dev_priv->guc.log.vma)
>>> -		return -EINVAL;
>>> -
>>> -	*val = i915_modparams.guc_log_level;
>>> +	*val = intel_guc_log_control_get(&dev_priv->guc);
>>>    	return 0;
>>>    }
>>> @@ -2515,10 +2512,10 @@ static int i915_guc_log_control_set(void *data, u64 val)
>>>    {
>>>    	struct drm_i915_private *dev_priv = data;
>>> -	if (!HAS_GUC(dev_priv))
>>> +	if (!USES_GUC(dev_priv))
>>>    		return -ENODEV;
>>> -	return intel_guc_log_control(&dev_priv->guc, val);
>>> +	return intel_guc_log_control_set(&dev_priv->guc, val);
>>>    }
>>>    DEFINE_SIMPLE_ATTRIBUTE(i915_guc_log_control_fops,
>>> diff --git a/drivers/gpu/drm/i915/intel_guc_log.c b/drivers/gpu/drm/i915/intel_guc_log.c
>>> index 7b5074e2120c..22a05320817b 100644
>>> --- a/drivers/gpu/drm/i915/intel_guc_log.c
>>> +++ b/drivers/gpu/drm/i915/intel_guc_log.c
>>> @@ -657,52 +657,55 @@ void intel_guc_log_destroy(struct intel_guc *guc)
>>>    	i915_vma_unpin_and_release(&guc->log.vma);
>>>    }
>>> -int intel_guc_log_control(struct intel_guc *guc, u64 control_val)
>>> +int intel_guc_log_control_get(struct intel_guc *guc)
>> Should we be passing guc_log as parameter and implement guc_log_to_guc()
>> function.
> This is the top-level interface exported for GuC users. In other words - callers
> of this function shouldn't have to know about struct guc_log (and the fact that
> it's located inside struct intel_guc).
>
>>> +{
>>> +	GEM_BUG_ON(!guc->log.vma);
>>> +	GEM_BUG_ON(i915_modparams.guc_log_level < 0);
>>> +
>>> +	return i915_modparams.guc_log_level;
>>> +}
>>> +
>>> +#define GUC_LOG_IS_ENABLED(x)		(x > 0)
>>> +#define GUC_LOG_LEVEL_TO_VERBOSITY(x)	(GUC_LOG_IS_ENABLED(x) ? x - 1 : 0)
>> This is bit misleading, can we make this macro return -1 if logging is to be
>> disabled. That way guc_log_control can be invoked with
>> single signed 32bit parameter.
> Note that guc_log_control is the function operating directly on GuC interface.
> This Host2GuC action really takes 3 arguments (2 parameters here) - enable,
> default_logging_enable, verbosity.
> As a consequence, I'd like to avoid placing any logic there. The macros are
> taking care of translation from guc_log_level modparam to values understood by
> GuC (host2guc params).
>
> I agree that the naming is confusing here.
> I'll go with LOG_LEVEL_TO_ENABLED(x) and LOG_LEVEL_TO_VERBOSITY(x) in second
> spin as suggested by Michał.
>
>>> +int intel_guc_log_control_set(struct intel_guc *guc, u64 val)
>>>    {
>>>    	struct drm_i915_private *dev_priv = guc_to_i915(guc);
>>> -	bool enable_logging = control_val > 0;
>>> -	u32 verbosity;
>>>    	int ret;
>>> -	if (!guc->log.vma)
>>> -		return -ENODEV;
>>> +	BUILD_BUG_ON(GUC_LOG_VERBOSITY_MIN != 0);
>>> +	GEM_BUG_ON(!guc->log.vma);
>>> +	GEM_BUG_ON(i915_modparams.guc_log_level < 0);
>>> -	BUILD_BUG_ON(GUC_LOG_VERBOSITY_MIN);
>>> -	if (control_val > 1 + GUC_LOG_VERBOSITY_MAX)
>>> +	/*
>>> +	 * GuC is recognizing log levels starting from 0 to max, we're using 0
>>> +	 * as indication that logging should be disablded.
>>> +	 */
>>> +	if (GUC_LOG_LEVEL_TO_VERBOSITY(val) < GUC_LOG_VERBOSITY_MIN ||
>> This check seems unnecessary as we currently don't have negative output for
>> G_L_L_T_V macro.
>> If we add negative value there, will need to remove this check.
> Yeah, agree. That's an error on my part, I wanted to do input validation here.
> This should probably be something more like:
> if (val < VERBOSITY_TO_LOG_LEVEL(GUC_LOG_VERBOSITY_MIN) ||
I think we should drop the min side check because val will never be 
negative and if we want to keep the check
then it  should be

#define GUC_LOG_LEVEL_DISABED    0
if (val < GUC_LOG_LEVEL_DISABLED) ||

Since we want to invoke guc_log_control to disable the logging.
>      val > VERBOSITY_TO_LOG_LEVEL(GUC_LOG_VERBOSITY_MAX))
>
> -Michał
>
>>> +	    GUC_LOG_LEVEL_TO_VERBOSITY(val) > GUC_LOG_VERBOSITY_MAX)
>>>    		return -EINVAL;
>>> -	/* This combination doesn't make sense & won't have any effect */
>>> -	if (!enable_logging && !i915_modparams.guc_log_level)
>>> -		return 0;
>>> +	mutex_lock(&dev_priv->drm.struct_mutex);
>>> -	verbosity = enable_logging ? control_val - 1 : 0;
>>> +	if (i915_modparams.guc_log_level == val) {
>>> +		ret = 0;
>>> +		goto out_unlock;
>>> +	}
>>> -	ret = mutex_lock_interruptible(&dev_priv->drm.struct_mutex);
>>> -	if (ret)
>>> -		return ret;
>>>    	intel_runtime_pm_get(dev_priv);
>>> -	ret = guc_log_control(guc, enable_logging, verbosity);
>>> +	ret = guc_log_control(guc, GUC_LOG_IS_ENABLED(val),
>>> +			      GUC_LOG_LEVEL_TO_VERBOSITY(val));
>>>    	intel_runtime_pm_put(dev_priv);
>>> -	mutex_unlock(&dev_priv->drm.struct_mutex);
>>> +	if (ret)
>>> +		goto out_unlock;
>>> -	if (ret < 0) {
>>> -		DRM_DEBUG_DRIVER("guc_logging_control action failed %d\n", ret);
>>> -		return ret;
>>> -	}
>>> +	i915_modparams.guc_log_level = val;
>>> -	if (enable_logging) {
>>> -		i915_modparams.guc_log_level = 1 + verbosity;
>>> +	mutex_unlock(&dev_priv->drm.struct_mutex);
>>> -		/*
>>> -		 * If log was disabled at boot time, then the relay channel file
>>> -		 * wouldn't have been created by now and interrupts also would
>>> -		 * not have been enabled. Try again now, just in case.
>>> -		 */
>>> +	if (GUC_LOG_IS_ENABLED(val) && !guc_log_has_runtime(guc)) {
>>>    		ret = guc_log_late_setup(guc);
>>> -		if (ret < 0) {
>>> -			DRM_DEBUG_DRIVER("GuC log late setup failed %d\n", ret);
>>> -			return ret;
>>> -		}
>>> +		if (ret)
>>> +			goto out;
>>>    		/* GuC logging is currently the only user of Guc2Host interrupts */
>>>    		mutex_lock(&dev_priv->drm.struct_mutex);
>>> @@ -710,7 +713,7 @@ int intel_guc_log_control(struct intel_guc *guc, u64 control_val)
>>>    		gen9_enable_guc_interrupts(dev_priv);
>>>    		intel_runtime_pm_put(dev_priv);
>>>    		mutex_unlock(&dev_priv->drm.struct_mutex);
>>> -	} else {
>>> +	} else if (!GUC_LOG_IS_ENABLED(val) && guc_log_has_runtime(guc)) {
>>>    		/*
>>>    		 * Once logging is disabled, GuC won't generate logs & send an
>>>    		 * interrupt. But there could be some data in the log buffer
>>> @@ -718,11 +721,13 @@ int intel_guc_log_control(struct intel_guc *guc, u64 control_val)
>>>    		 * buffer state and then collect the left over logs.
>>>    		 */
>>>    		guc_flush_logs(guc);
>>> -
>>> -		/* As logging is disabled, update log level to reflect that */
>>> -		i915_modparams.guc_log_level = 0;
>>>    	}
>>> +	return 0;
>>> +
>>> +out_unlock:
>>> +	mutex_unlock(&dev_priv->drm.struct_mutex);
>>> +out:
>>>    	return ret;
>>>    }
>>> diff --git a/drivers/gpu/drm/i915/intel_guc_log.h b/drivers/gpu/drm/i915/intel_guc_log.h
>>> index dab0e949567a..141ce9ca22ce 100644
>>> --- a/drivers/gpu/drm/i915/intel_guc_log.h
>>> +++ b/drivers/gpu/drm/i915/intel_guc_log.h
>>> @@ -64,7 +64,8 @@ void intel_guc_log_destroy(struct intel_guc *guc);
>>>    void intel_guc_log_init_early(struct intel_guc *guc);
>>>    int intel_guc_log_relay_create(struct intel_guc *guc);
>>>    void intel_guc_log_relay_destroy(struct intel_guc *guc);
>>> -int intel_guc_log_control(struct intel_guc *guc, u64 control_val);
>>> +int intel_guc_log_control_get(struct intel_guc *guc);
>>> +int intel_guc_log_control_set(struct intel_guc *guc, u64 control_val);
>>>    void i915_guc_log_register(struct drm_i915_private *dev_priv);
>>>    void i915_guc_log_unregister(struct drm_i915_private *dev_priv);
>> -- 
>> Thanks,
>> Sagar
>>

-- 
Thanks,
Sagar

_______________________________________________
Intel-gfx mailing list
Intel-gfx@lists.freedesktop.org
https://lists.freedesktop.org/mailman/listinfo/intel-gfx