Re: [Intel-gfx] [PATCH 09/15] drm/i915/pxp: add huc authentication and loading command

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

Reviewed-by: Alan Previn <alan.previn.teres.alexis@intel.com>

On 6/9/2022 4:19 PM, Ceraolo Spurio, Daniele wrote:
> From: Tomas Winkler <tomas.winkler@intel.com>
>
> Add support for loading HuC via a pxp stream command.
>
> Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
> Signed-off-by: Vitaly Lubart <vitaly.lubart@intel.com>
> Signed-off-by: Daniele Ceraolo Spurio <daniele.ceraolospurio@intel.com>
> Cc: Alan Previn <alan.previn.teres.alexis@intel.com>
> ---
>   drivers/gpu/drm/i915/Makefile                 |  3 +-
>   drivers/gpu/drm/i915/pxp/intel_pxp_huc.c      | 69 +++++++++++++++++++
>   drivers/gpu/drm/i915/pxp/intel_pxp_huc.h      | 15 ++++
>   .../drm/i915/pxp/intel_pxp_tee_interface.h    | 21 ++++++
>   4 files changed, 107 insertions(+), 1 deletion(-)
>   create mode 100644 drivers/gpu/drm/i915/pxp/intel_pxp_huc.c
>   create mode 100644 drivers/gpu/drm/i915/pxp/intel_pxp_huc.h
>
> diff --git a/drivers/gpu/drm/i915/Makefile b/drivers/gpu/drm/i915/Makefile
> index 5d3aa4807def..8d90e653958c 100644
> --- a/drivers/gpu/drm/i915/Makefile
> +++ b/drivers/gpu/drm/i915/Makefile
> @@ -306,7 +306,8 @@ i915-y += i915_perf.o
>   # Protected execution platform (PXP) support. Base support is required for HuC
>   i915-y += \
>   	pxp/intel_pxp.o \
> -	pxp/intel_pxp_tee.o
> +	pxp/intel_pxp_tee.o \
> +	pxp/intel_pxp_huc.o
>   
>   i915-$(CONFIG_DRM_I915_PXP) += \
>   	pxp/intel_pxp_cmd.o \
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_huc.c b/drivers/gpu/drm/i915/pxp/intel_pxp_huc.c
> new file mode 100644
> index 000000000000..6d25f436f329
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_huc.c
> @@ -0,0 +1,69 @@
> +// SPDX-License-Identifier: MIT
> +/*
> + * Copyright(c) 2021, Intel Corporation. All rights reserved.
> + */
> +
> +#include "drm/i915_drm.h"
> +#include "i915_drv.h"
> +
> +#include "gem/i915_gem_region.h"
> +#include "gt/intel_gt.h"
> +
> +#include "intel_pxp.h"
> +#include "intel_pxp_huc.h"
> +#include "intel_pxp_tee.h"
> +#include "intel_pxp_types.h"
> +#include "intel_pxp_tee_interface.h"
> +
> +int intel_pxp_huc_load_and_auth(struct intel_pxp *pxp)
> +{
> +	struct intel_gt *gt = pxp_to_gt(pxp);
> +	struct intel_huc *huc = &gt->uc.huc;
> +	struct pxp_tee_start_huc_auth_in huc_in = {0};
> +	struct pxp_tee_start_huc_auth_out huc_out = {0};
> +	dma_addr_t huc_phys_addr;
> +	u8 client_id = 0;
> +	u8 fence_id = 0;
> +	int err;
> +
> +	if (!pxp->pxp_component)
> +		return -ENODEV;
> +
> +	huc_phys_addr = i915_gem_object_get_dma_address(huc->fw.obj, 0);
> +
> +	/* write the PXP message into the lmem (the sg list) */
> +	huc_in.header.api_version = PXP_TEE_43_APIVER;
> +	huc_in.header.command_id  = PXP_TEE_43_START_HUC_AUTH;
> +	huc_in.header.status      = 0;
> +	huc_in.header.buffer_len  = sizeof(huc_in.huc_base_address);
> +	huc_in.huc_base_address   = huc_phys_addr;
> +
> +	err = intel_pxp_tee_stream_message(pxp, client_id, fence_id,
> +					   &huc_in, sizeof(huc_in),
> +					   &huc_out, sizeof(huc_out));
> +	if (err < 0) {
> +		drm_err(&gt->i915->drm,
> +			"Failed to send HuC load and auth command to GSC [%d]!\n",
> +			err);
> +		return err;
> +	}
> +
> +	/*
> +	 * HuC does sometimes survive suspend/resume (it depends on how "deep"
> +	 * a sleep state the device reaches) so we can end up here on resume
> +	 * with HuC already loaded, in which case the GSC will return
> +	 * PXP_STATUS_OP_NOT_PERMITTED. We can therefore consider the GuC
> +	 * correctly transferred in this scenario; if the same error is ever
> +	 * returned with HuC not loaded we'll still catch it when we check the
> +	 * authentication bit later.
> +	 */
> +	if (huc_out.header.status != PXP_STATUS_SUCCESS &&
> +	    huc_out.header.status != PXP_STATUS_OP_NOT_PERMITTED) {
> +		drm_err(&gt->i915->drm,
> +			"HuC load failed with GSC error = 0x%x\n",
> +			huc_out.header.status);
> +		return -EPROTO;
> +	}
> +
> +	return 0;
> +}
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_huc.h b/drivers/gpu/drm/i915/pxp/intel_pxp_huc.h
> new file mode 100644
> index 000000000000..6cf2d00548c0
> --- /dev/null
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_huc.h
> @@ -0,0 +1,15 @@
> +/* SPDX-License-Identifier: MIT */
> +/*
> + * Copyright(c) 2021, Intel Corporation. All rights reserved.
> + */
> +
> +#ifndef __INTEL_PXP_HUC_H__
> +#define __INTEL_PXP_HUC_H__
> +
> +#include <linux/types.h>
> +
> +struct intel_pxp;
> +
> +int intel_pxp_huc_load_and_auth(struct intel_pxp *pxp);
> +
> +#endif /* __INTEL_PXP_HUC_H__ */
> diff --git a/drivers/gpu/drm/i915/pxp/intel_pxp_tee_interface.h b/drivers/gpu/drm/i915/pxp/intel_pxp_tee_interface.h
> index 36e9b0868f5c..1de98959a89d 100644
> --- a/drivers/gpu/drm/i915/pxp/intel_pxp_tee_interface.h
> +++ b/drivers/gpu/drm/i915/pxp/intel_pxp_tee_interface.h
> @@ -9,8 +9,20 @@
>   #include <linux/types.h>
>   
>   #define PXP_TEE_APIVER 0x40002
> +#define PXP_TEE_43_APIVER 0x00040003
>   #define PXP_TEE_ARB_CMDID 0x1e
>   #define PXP_TEE_ARB_PROTECTION_MODE 0x2
> +#define PXP_TEE_43_START_HUC_AUTH   0x0000003A
> +
> +/*
> + * there are a lot of status codes for PXP, but we only define the ones we
> + * actually can handle in the driver. other failure codes will be printed to
> + * error msg for debug.
> + */
> +enum pxp_status {
> +	PXP_STATUS_SUCCESS = 0x0,
> +	PXP_STATUS_OP_NOT_PERMITTED = 0x4013
> +};
>   
>   /* PXP TEE message header */
>   struct pxp_tee_cmd_header {
> @@ -33,4 +45,13 @@ struct pxp_tee_create_arb_out {
>   	struct pxp_tee_cmd_header header;
>   } __packed;
>   
> +struct pxp_tee_start_huc_auth_in {
> +	struct pxp_tee_cmd_header header;
> +	__le64                    huc_base_address;
> +};
> +
> +struct pxp_tee_start_huc_auth_out {
> +	struct pxp_tee_cmd_header header;
> +};
> +
>   #endif /* __INTEL_PXP_TEE_INTERFACE_H__ */