[Intel-gfx] [PATCH 8/8] drm/i915/get_params: Add HuC status to getparams

[Arkadiusz Hiler]

On Fri, Dec 09, 2016 at 01:59:45PM +0100, Michal Wajdeczko wrote:
> On Thu, Dec 08, 2016 at 03:02:19PM -0800, anushasr wrote:
> > From: Peter Antoine <peter.antoine at intel.com>
> > 
> > This patch will allow for getparams to return the status of the HuC.
> > As the HuC has to be validated by the GuC this patch uses the validated
> > status to show when the HuC is loaded and ready for use. You cannot use
> > the loaded status as with the GuC as the HuC is verified after it is
> > loaded and is not usable until it is verified.
> > 
> > v2: removed the forewakes as the registers are already force-woken.
> >      (T.Ursulin)
> > v4: rebased.
> > v5: rebased on top of drm-tip.
> > v6: rebased. Removed any reference to intel_huc.h
> > 
> > Signed-off-by: Peter Antoine <peter.antoine at intel.com>
> > Reviewed-by: Arkadiusz Hiler <arkadiusz.hiler at intel.com>
> > ---
> >  drivers/gpu/drm/i915/i915_drv.c         |  4 ++++
> >  drivers/gpu/drm/i915/intel_huc_loader.c | 12 ++++++++++++
> >  drivers/gpu/drm/i915/intel_uc.h         |  1 +
> >  include/uapi/drm/i915_drm.h             |  1 +
> >  4 files changed, 18 insertions(+)
> > 
> > diff --git a/drivers/gpu/drm/i915/i915_drv.c b/drivers/gpu/drm/i915/i915_drv.c
> > index 85a47c2..6be06a27 100644
> > --- a/drivers/gpu/drm/i915/i915_drv.c
> > +++ b/drivers/gpu/drm/i915/i915_drv.c
> > @@ -49,6 +49,7 @@
> >  #include "i915_trace.h"
> >  #include "i915_vgpu.h"
> >  #include "intel_drv.h"
> > +#include "intel_uc.h"
> >  
> >  static struct drm_driver driver;
> >  
> > @@ -349,6 +350,9 @@ static int i915_getparam(struct drm_device *dev, void *data,
> >  		 */
> >  		value = 1;
> >  		break;
> > +	case I915_PARAM_HAS_HUC:
> 
> For me this param name does not match returned result which maybe misleading.
> Note that other HAS params return static driver/hw capability, not runtime.
> 
> I guess PARAM_HUC_STATUS would be better (0=no huc, 1=pending, 2=ok, -1=failed)
> And you can cache huc status in intel_huc struct and make final modification in
> intel_huc_auth() function to avoid registry read (unless we want to detect later
> crash of the huc using this reg read)

Why should userspace care for those intermediary states? From what I
know (docs and patches from the cover letter) userspace is interested
only in being able to use HuC. If something is not working you have
DebugFS for that exact purpose.

As of cacheing - seems like a good idea to limit reg reads.

> > +		value = intel_is_huc_valid(dev_priv);
> > +		break;
> >  	default:
> >  		DRM_DEBUG("Unknown parameter %d\n", param->param);
> >  		return -EINVAL;
> > diff --git a/drivers/gpu/drm/i915/intel_huc_loader.c b/drivers/gpu/drm/i915/intel_huc_loader.c
> > index 96fc727..6704cc8 100644
> > --- a/drivers/gpu/drm/i915/intel_huc_loader.c
> > +++ b/drivers/gpu/drm/i915/intel_huc_loader.c
> > @@ -289,3 +289,15 @@ void intel_huc_fini(struct drm_device *dev)
> >  	huc_fw->fetch_status = UC_FIRMWARE_NONE;
> >  }
> >  
> > +/**
> > + * intel_is_huc_valid() - Check to see if the HuC is fully loaded.
> > + * @dev_priv:	drm device to check.
> > + *
> > + * This function will return true if the guc has been loaded and
> 
> Please change function return type to bool to match this description.
> 
> > + * has valid firmware. The simplest way of doing this is to check
> > + * if the HuC has been validated, if so it must have been loaded.
> > + */
> > +int intel_is_huc_valid(struct drm_i915_private *dev_priv)
> > +{
> > +	return ((I915_READ(HUC_STATUS2) & HUC_FW_VERIFIED) != 0);
> > +}
> > diff --git a/drivers/gpu/drm/i915/intel_uc.h b/drivers/gpu/drm/i915/intel_uc.h
> > index 1db8bc2..ccd3f69 100644
> > --- a/drivers/gpu/drm/i915/intel_uc.h
> > +++ b/drivers/gpu/drm/i915/intel_uc.h
> > @@ -226,6 +226,7 @@ int i915_guc_log_control(struct drm_i915_private *dev_priv, u64 control_val);
> >  void intel_huc_init(struct drm_i915_private *dev_priv);
> >  void intel_huc_fini(struct drm_device *dev);
> >  int intel_huc_load(struct drm_i915_private *dev_priv);
> > +int intel_is_huc_valid(struct drm_i915_private *dev_priv);
> >  
> >  #endif
> >  #endif
> > diff --git a/include/uapi/drm/i915_drm.h b/include/uapi/drm/i915_drm.h
> > index da32c2f..3e1964c 100644
> > --- a/include/uapi/drm/i915_drm.h
> > +++ b/include/uapi/drm/i915_drm.h
> > @@ -395,6 +395,7 @@ typedef struct drm_i915_irq_wait {
> >   * priorities and the driver will attempt to execute batches in priority order.
> >   */
> >  #define I915_PARAM_HAS_SCHEDULER	 41
> > +#define I915_PARAM_HAS_HUC		 42
> >  
> >  typedef struct drm_i915_getparam {
> >  	__s32 param;
> > -- 
> > 2.7.4
> > 
> > _______________________________________________
> > Intel-gfx mailing list
> > Intel-gfx at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/intel-gfx
> _______________________________________________
> Intel-gfx mailing list
> Intel-gfx at lists.freedesktop.org
> https://lists.freedesktop.org/mailman/listinfo/intel-gfx

-- 
Cheers,
Arek