Re: [Intel-gfx] [PATCH v4 06/17] drm/i915/pxp: Implement funcs to create the TEE channel

["Teres Alexis, Alan Previn" <alan.previn.teres.alexis@intel.com>]

On Mon, 2021-05-24 at 22:47 -0700, Daniele Ceraolo Spurio wrote:
> From: "Huang, Sean Z" <sean.z.huang@intel.com>
> 
> Implement the funcs to create the TEE channel, so kernel can
> send the TEE commands directly to TEE for creating the arbitrary
> (default) session.
> 
> v2: fix locking, don't pollute dev_priv (Chris)
> 
> v3: wait for mei PXP component to be bound.
> 
> Signed-off-by: Huang, Sean Z <sean.z.huang@intel.com>
> Signed-off-by: Daniele Ceraolo Spurio <
> daniele.ceraolospurio@intel.com>
> Cc: Chris Wilson <chris@chris-wilson.co.uk>
> Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com> #v2
> ---
>  drivers/gpu/drm/i915/Makefile              |  3 +-
>  drivers/gpu/drm/i915/pxp/intel_pxp.c       | 13 ++++
>  drivers/gpu/drm/i915/pxp/intel_pxp_tee.c   | 87
> ++++++++++++++++++++++
>  drivers/gpu/drm/i915/pxp/intel_pxp_tee.h   | 14 ++++
>  drivers/gpu/drm/i915/pxp/intel_pxp_types.h |  3 +
>  5 files changed, 119 insertions(+), 1 deletion(-)
>  create mode 100644 drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
>  create mode 100644 drivers/gpu/drm/i915/pxp/intel_pxp_tee.h
> 
> diff --git a/drivers/gpu/drm/i915/Makefile
> b/drivers/gpu/drm/i915/Makefile
> index efd950122e40..0dfff52fea24 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -275,7 +275,8 @@ i915-y += i915_perf.o
>  
>  # Protected execution platform (PXP) support
>  i915-$(CONFIG_DRM_I915_PXP) += \
> -	pxp/intel_pxp.o
> +	pxp/intel_pxp.o \
> +	pxp/intel_pxp_tee.o
>  
>  # Post-mortem debug and GPU hang state capture
>  i915-$(CONFIG_DRM_I915_CAPTURE_ERROR) += i915_gpu_error.o
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp.c
> b/drivers/gpu/drm/i915/pxp/intel_pxp.c
> index 3255c6da34e8..5df2a09c9e4b 100644
> --- a/drivers/gpu/drm/i915/pxp/intel_pxp.c
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp.c
> @@ -3,6 +3,7 @@
>   * Copyright(c) 2020 Intel Corporation.
>   */
>  #include "intel_pxp.h"
> +#include "intel_pxp_tee.h"
>  #include "gt/intel_context.h"
>  #include "i915_drv.h"
>  
> @@ -50,7 +51,16 @@ void intel_pxp_init(struct intel_pxp *pxp)
>  	if (ret)
>  		return;
>  
> +	ret = intel_pxp_tee_component_init(pxp);
> +	if (ret)
> +		goto out_context;
> +
>  	drm_info(&gt->i915->drm, "Protected Xe Path (PXP) protected
> content support initialized\n");
> +
> +	return;
> +
> +out_context:
> +	destroy_vcs_context(pxp);
>  }
>  
>  void intel_pxp_fini(struct intel_pxp *pxp)
> @@ -58,5 +68,8 @@ void intel_pxp_fini(struct intel_pxp *pxp)
>  	if (!intel_pxp_is_enabled(pxp))
>  		return;
>  
> +	intel_pxp_tee_component_fini(pxp);
> +
>  	destroy_vcs_context(pxp);
> +
>  }
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
> b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
> new file mode 100644
> index 000000000000..4ed234d8584f
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.c
> @@ -0,0 +1,87 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright(c) 2020 Intel Corporation.
> + */
> +
> +#include <linux/component.h>
> +#include "drm/i915_pxp_tee_interface.h"
> +#include "drm/i915_component.h"
> +#include "i915_drv.h"
> +#include "intel_pxp.h"
> +#include "intel_pxp_tee.h"
> +
> +static inline struct intel_pxp *i915_dev_to_pxp(struct device
> *i915_kdev)
> +{
> +	return &kdev_to_i915(i915_kdev)->gt.pxp;
> +}
> +
> +/**
> + * i915_pxp_tee_component_bind - bind function to pass the function
> pointers to pxp_tee
> + * @i915_kdev: pointer to i915 kernel device
> + * @tee_kdev: pointer to tee kernel device
> + * @data: pointer to pxp_tee_master containing the function pointers
> + *
> + * This bind function is called during the system boot or resume
> from system sleep.
> + *
> + * Return: return 0 if successful.
> + */
> +static int i915_pxp_tee_component_bind(struct device *i915_kdev,
> +				       struct device *tee_kdev, void
> *data)
> +{
> +	struct intel_pxp *pxp = i915_dev_to_pxp(i915_kdev);
> +
> +	pxp->pxp_component = data;
> +	pxp->pxp_component->tee_dev = tee_kdev;
> +
> +	return 0;
> +}
> +
> +static void i915_pxp_tee_component_unbind(struct device *i915_kdev,
> +					  struct device *tee_kdev, void
> *data)
> +{
> +	struct intel_pxp *pxp = i915_dev_to_pxp(i915_kdev);
> +
> +	pxp->pxp_component = NULL;
> +}
> +
> +static const struct component_ops i915_pxp_tee_component_ops = {
> +	.bind   = i915_pxp_tee_component_bind,
> +	.unbind = i915_pxp_tee_component_unbind,
> +};
> +
> +int intel_pxp_tee_component_init(struct intel_pxp *pxp)
> +{
> +	int ret;
> +	struct intel_gt *gt = pxp_to_gt(pxp);
> +	struct drm_i915_private *i915 = gt->i915;
> +
> +	ret = component_add_typed(i915->drm.dev,
> &i915_pxp_tee_component_ops,
> +				  I915_COMPONENT_PXP);
> +	if (ret < 0) {
> +		drm_err(&i915->drm, "Failed to add PXP component
> (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	/*
> +	 * Adding the component does not guarantee that it will bind
> properly,
> +	 * so make sure to wait until it does.
> +	 */
> +	ret = wait_for(pxp->pxp_component, 50);
> +	if (ret) {
> +		drm_err(&i915->drm, "Failed to bind PXP component 

Based on my testing with the 'wip-igt-pxp', this failed here because
the mei-pxp was getting loaded multiple seconds later than i915. We
might need to consider having a check for pxp_component availability on
every IOCTL to ensure binding actually occured and succeed (==pxp-
supported), or occured and failed (==pxp-failed, disable it), or didn't
occure yet (==pending-retry?).

> (%d)\n", ret);
> +		return ret;
> +	}
> +
> +	return 0;
> +}
> +
> +void intel_pxp_tee_component_fini(struct intel_pxp *pxp)
> +{
> +	struct intel_gt *gt = pxp_to_gt(pxp);
> +	struct drm_i915_private *i915 = gt->i915;
> +
> +	if (!pxp->pxp_component)
> +		return;
> +
> +	component_del(i915->drm.dev, &i915_pxp_tee_component_ops);
> +}
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee.h
> b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.h
> new file mode 100644
> index 000000000000..23d050a5d3e7
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee.h
> @@ -0,0 +1,14 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright(c) 2020, Intel Corporation. All rights reserved.
> + */
> +
> +#ifndef __INTEL_PXP_TEE_H__
> +#define __INTEL_PXP_TEE_H__
> +
> +#include "intel_pxp.h"
> +
> +int intel_pxp_tee_component_init(struct intel_pxp *pxp);
> +void intel_pxp_tee_component_fini(struct intel_pxp *pxp);
> +
> +#endif /* __INTEL_PXP_TEE_H__ */
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
> b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
> index bd12c520e60a..3e95d21513e8 100644
> --- a/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_types.h
> @@ -7,8 +7,11 @@
>  #define __INTEL_PXP_TYPES_H__
>  
>  struct intel_context;
> +struct i915_pxp_component;
>  
>  struct intel_pxp {
> +	struct i915_pxp_component *pxp_component;
> +
>  	struct intel_context *ce;
>  };
>