/** @file
  Library that implements the Arm CCA Realm Service Interface calls.

  Copyright (c) 2022 - 2024, Arm Limited. All rights reserved.<BR>
  SPDX-License-Identifier: BSD-2-Clause-Patent

    - Rsi or RSI   - Realm Service Interface
    - IPA          - Intermediate Physical Address
    - RIPAS        - Realm IPA state
    - RIM          - Realm Initial Measurement
    - REM          - Realm Extensible Measurement

  @par Reference(s):
   - Realm Management Monitor (RMM) Specification, version 1.0-rel0
     (https://developer.arm.com/documentation/den0137/)
**/

#pragma once

#include <Base.h>

/**
  A macro defining the size of a Realm Granule.
  See Section A2.2, RMM Specification, version 1.0-rel0
  DNBXXX A Granule is a unit of physical memory whose size is 4KB.
*/
#define ARM_CCA_REALM_GRANULE_SIZE  SIZE_4KB

/**
  A macro defining the mask for the RSI RIPAS type.
  See Section B4.4.7 RsiRipas type, RMM Specification, version 1.0-rel0.
*/
#define ARM_CCA_RIPAS_TYPE_MASK  0xFF

/* Maximum challenge data size in bits.
*/
#define ARM_CCA_MAX_CHALLENGE_DATA_SIZE_BITS  512

/* Minimum recommended challenge data size in bits.
*/
#define ARM_CCA_MIN_CHALLENGE_DATA_SIZE_BITS  256

/* Maximum measurement data size in bytes.
  See Section C1.17 RmmRealmMeasurement type, RMM Specification, version 1.0-rel0
  The width of the RmmRealmMeasurement type is 512 bits.
*/
#define ARM_CCA_MAX_MEASUREMENT_DATA_SIZE_BYTES  64

/* Minimum and Maximum indices for REMs
  See Section A2.1.3 Realm attributes, RMM Specification, version 1.0-rel0
  IFMPYL - Attributes of a Realm include an array of measurement values. The
  first entry in this array is a RIM. The remaining entries in this array are
  REMs.
*/
#define ARM_CCA_MIN_REM_INDEX  1
#define ARM_CCA_MAX_REM_INDEX  4

/* The values of the RsiHashAlgorithm enumeration.
   SHA-256 (Secure Hash Standard (SHS))
*/
#define ARM_CCA_RSI_HASH_SHA_256  0

/* The values of the RsiHashAlgorithm enumeration.
   SHA-512 (Secure Hash Standard (SHS))
*/
#define ARM_CCA_RSI_HASH_SHA_512  1

/* The RsiRipasChangeFlags fieldset contains flags provided by
   the Realm when requesting a RIPAS change.
   See section B5.4.9 RsiRipasChangeFlags type in the
   RMM Specification, version 1.0-rel0.
   The following macros prefixed RIPAS_CHANGE_FLAGS_xxx
   define the values of the RsiRipasChangeFlags fieldset.
*/

/* A RIPAS change from DESTROYED should not be permitted.
  See section B4.4.8 RsiRipasChangeDestroyed type in the
  RMM Specification, version 1.0-rel0
*/
#define ARM_CCA_RIPAS_CHANGE_FLAGS_RSI_NO_CHANGE_DESTROYED  0

/* A RIPAS change from DESTROYED should be permitted.
  See section B4.4.8 RsiRipasChangeDestroyed type in the
  RMM Specification, version 1.0-rel0
*/
#define ARM_CCA_RIPAS_CHANGE_FLAGS_RSI_CHANGE_DESTROYED  1

/* The RsiResponse type is a value returned by the
   RSI_IPA_STATE_SET command and represents whether
   the Host accepted or rejected a Realm request.
   See section B5.4.6 RsiResponse type in the
   RMM Specification, version 1.0-rel0.
   The width of the RsiResponse enumeration is 1 bit
   and the following macros prefixed RIPAS_CHANGE_RESPONSE_xxx
   define the values of the RsiResponse type.
*/

/* The RIPAS change request to RAM was accepted
   by the host.
*/
#define ARM_CCA_RIPAS_CHANGE_RESPONSE_ACCEPT  0

/* The RIPAS change request to RAM was rejected
   by the host.
*/
#define ARM_CCA_RIPAS_CHANGE_RESPONSE_REJECT  1

/* A mask for the RSI Response bit */
#define ARM_CCA_RSI_RESPONSE_MASK  BIT0

/** An enum describing the RSI RIPAS.
   See Section A5.2.2 Realm IPA state, RMM Specification, version 1.0-rel0
*/
typedef enum ArmCcaRipas {
  RipasEmpty,      ///< Unused IPA location.
  RipasRam,        ///< Private code or data owned by the Realm.
  RipasDestroyed,  ///< An address which is inaccessible to the Realm.
  RipasDev,        ///< MMIO address where an assigned Realm device is mapped.
  RipasMax         ///< A valid RIPAS type value is less than RipasMax.
} ARM_CCA_RIPAS;

/* The maximum length of the Realm Personalisation Value (RPV).
*/
#define ARM_CCA_REALM_CFG_RPV_SIZE  64

/* The size of the Realm Config is 4KB.
*/
#define ARM_CCA_REALM_CFG_SIZE  SIZE_4KB

/* Helper macros to define the RealmConfig structure.
*/
#define ARM_CCA_REALM_CFG_OFFSET_IPA_WIDTH  0
#define ARM_CCA_REALM_CFG_OFFSET_HASH_ALGO  (ARM_CCA_REALM_CFG_OFFSET_IPA_WIDTH + sizeof (UINT64))
#define ARM_CCA_REALM_CFG_OFFSET_RESERVED   (ARM_CCA_REALM_CFG_OFFSET_HASH_ALGO + sizeof (UINT8))
#define ARM_CCA_REALM_CFG_OFFSET_RPV        0x200
#define ARM_CCA_REALM_CFG_OFFSET_RESERVED1  (ARM_CCA_REALM_CFG_OFFSET_RPV + ARM_CCA_REALM_CFG_RPV_SIZE)

/* The maximum size of the RsiHostCallArgs structure.
*/
#define ARM_CCA_RSI_HOST_CALL_ARGS_SIZE  0x100

#pragma pack(1)

/** A structure describing the Realm Configuration.
  See Section B5.4.5 RsiRealmConfig type, RMM Specification, version 1.0-rel0
  The width of the RsiRealmConfig structure is 4096 (0x1000) bytes.
*/
typedef struct ArmCcaRealmConfig {
  /// Width of IPA in bits.
  UINT64    IpaWidth;
  /// Width of the RsiHashAlgorithm enumeration is 8 bits.
  UINT8     HashAlgorithm;
  /// Reserved
  UINT8     Reserved[ARM_CCA_REALM_CFG_OFFSET_RPV - ARM_CCA_REALM_CFG_OFFSET_RESERVED];
  /// Realm Personalisation Value
  UINT8     Rpv[ARM_CCA_REALM_CFG_RPV_SIZE];
  /// Unused bits of the RsiRealmConfig structure should be zero.
  UINT8     Reserved1[ARM_CCA_REALM_CFG_SIZE - ARM_CCA_REALM_CFG_OFFSET_RESERVED1];
} ARM_CCA_REALM_CONFIG;

/** A structure describing the Host Call arguments
    See Section 5.4.3 RsiHostCall type, RMM Specification, version 1.0-rel0
*/
typedef struct ArmCcaRsiHostCallArgs {
  UINT16    Imm;
  UINT8     Reserved1[6];

  UINT64    Gprs0;
  UINT64    Gprs1;
  UINT64    Gprs2;
  UINT64    Gprs3;
  UINT64    Gprs4;
  UINT64    Gprs5;
  UINT64    Gprs6;
  UINT64    Gprs7;
  UINT64    Gprs8;
  UINT64    Gprs9;
  UINT64    Gprs10;
  UINT64    Gprs11;
  UINT64    Gprs12;
  UINT64    Gprs13;
  UINT64    Gprs14;
  UINT64    Gprs15;
  UINT64    Gprs16;
  UINT64    Gprs17;
  UINT64    Gprs18;
  UINT64    Gprs19;
  UINT64    Gprs20;
  UINT64    Gprs21;
  UINT64    Gprs22;
  UINT64    Gprs23;
  UINT64    Gprs24;
  UINT64    Gprs25;
  UINT64    Gprs26;
  UINT64    Gprs27;
  UINT64    Gprs28;
  UINT64    Gprs29;
  UINT64    Gprs30;
} ARM_CCA_RSI_HOST_CALL_ARGS;

#pragma pack()

/**
  Retrieve an attestation token from the RMM.

  @param [in]       ChallengeData         Pointer to the challenge data to be
                                          included in the attestation token.
  @param [in]       ChallengeDataSizeBits Size of the challenge data in bits.
  @param [out]      TokenBuffer           Pointer to a buffer to store the
                                          retrieved attestation token.
  @param [out]      TokenBufferSize       Length of token data returned.

  Note: The TokenBuffer allocated must be freed by the caller
  using RsiFreeAttestationToken().

  @retval RETURN_SUCCESS            Success.
  @retval RETURN_INVALID_PARAMETER  A parameter is invalid.
  @retval RETURN_OUT_OF_RESOURCES   Out of resources.
  @retval RETURN_ABORTED            The operation was aborted as the state
                                    of the Realm or REC does not match the
                                    state expected by the command.
                                    Or the Token generation failed for an
                                    unknown or IMPDEF reason.
  @retval RETURN_NOT_READY          The operation requested by the command
                                    is not complete.
  @retval RETURN_BAD_BUFFER_SIZE    The token buffer size returned in an
                                    earlier call to RSI_ATTESTATION_TOKEN_INIT
                                    was insufficient to complete the operation.
**/
RETURN_STATUS
EFIAPI
ArmCcaRsiGetAttestationToken (
  IN      CONST UINT8   *CONST  ChallengeData,
  IN            UINT64          ChallengeDataSizeBits,
  OUT           UINT8  **CONST  TokenBuffer,
  OUT           UINT64  *CONST  TokenBufferSize
  );

/**
  Free the attestation token buffer.

  @param [in]      TokenBuffer           Pointer to the retrieved
                                         attestation token.
  @param [in]      TokenBufferSize       Size of the token buffer.
**/
VOID
ArmCcaRsiFreeAttestationToken (
  IN           UINT8  *CONST  TokenBuffer,
  IN           UINT64  CONST  TokenBufferSize
  );

/**
  Returns the IPA state for the page pointed by the address.

  @param [in]       Base        Base of target IPA region.
  @param [in, out]  Top         End  of target IPA region on input.
                                Top of IPA region which has the
                                reported RIPAS value on return.
  @param [out]  State           The RIPAS state for the address specified.

  @retval RETURN_SUCCESS            Success.
  @retval RETURN_INVALID_PARAMETER  A parameter is invalid.
**/
RETURN_STATUS
EFIAPI
ArmCcaRsiGetIpaState (
  IN      UINT64         *Base,
  IN OUT  UINT64         **Top,
  OUT     ARM_CCA_RIPAS  *State
  );

/**
  Sets the IPA state for the pages pointed by the memory range.

  @param [in]   Address     Address to the start of the memory range.
  @param [in]   Size        Length of the memory range.
  @param [in]   State       The RIPAS state to be configured.
  @param [in]   Flags       The RIPAS change flags.

  @retval RETURN_SUCCESS            Success.
  @retval RETURN_INVALID_PARAMETER  A parameter is invalid.
  @retval RETURN_ACCESS_DENIED      RIPAS change request was rejected.
**/
RETURN_STATUS
EFIAPI
ArmCcaRsiSetIpaState (
  IN  UINT64         *Address,
  IN  UINT64         Size,
  IN  ARM_CCA_RIPAS  State,
  IN  UINT64         Flags
  );

/**
  Extends a measurement to a REM.

  @param [in] MeasurementIndex     Index of the REM.
  @param [in] Measurement          Pointer to the measurement buffer.
  @param [in] MeasurementSize      Size of the measurement data.

  @retval RETURN_SUCCESS            Success.
  @retval RETURN_INVALID_PARAMETER  A parameter is invalid.
**/
RETURN_STATUS
EFIAPI
ArmCcaRsiExtendMeasurement (
  IN        UINTN          MeasurementIndex,
  IN  CONST UINT8  *CONST  Measurement,
  IN        UINTN          MeasurementSize
  );

/**
  Read the measurement value from a REM.

  @param [in]   MeasurementIndex     Index of the REM.
  @param [out]  MeasurementBuffer     Pointer to store the measurement data.
  @param [in]   MeasurementBufferSize Size of the measurement buffer.

  @retval RETURN_SUCCESS            Success.
  @retval RETURN_INVALID_PARAMETER  A parameter is invalid.
**/
RETURN_STATUS
EFIAPI
ArmCcaRsiReadMeasurement (
  IN    UINTN          MeasurementIndex,
  OUT   UINT8  *CONST  MeasurementBuffer,
  IN    UINTN          MeasurementBufferSize
  );

/**
  Read the Realm Configuration.

  @param [out]  Config     Pointer to the address of the buffer to retrieve
                           the Realm configuration.

  Note: The buffer to retrieve the Realm configuration must be aligned to the
        Realm granule size.

  @retval RETURN_SUCCESS            Success.
  @retval RETURN_INVALID_PARAMETER  A parameter is invalid.
**/
RETURN_STATUS
EFIAPI
ArmCcaRsiGetRealmConfig (
  IN  ARM_CCA_REALM_CONFIG  *Config
  );

/**
  Make a Host Call.

  A Host call can be used by a Realm to make a hypercall.
  On Realm execution of HVC, an Unknown exception is taken to the Realm.

  @param [in] Args    Pointer to the IPA of the Host call data
                      structure.

  Note: The IPA of the Host call arguments data structure must be aligned
         to the Realm granule size.

  @retval RETURN_SUCCESS            Success.
  @retval RETURN_INVALID_PARAMETER  A parameter is invalid.
**/
RETURN_STATUS
EFIAPI
ArmCcaRsiHostCall (
  IN  ARM_CCA_RSI_HOST_CALL_ARGS  *Args
  );

/**
   Get the version of the RSI implementation.

  @param [out] UefiImpl     The version of the RSI specification
                            implemented by the UEFI firmware.
  @param [out] RmmImplLow   The low version of the RSI specification
                            implemented by the RMM.
  @param [out] RmmImplHigh  The high version of the RSI specification
                            implemented by the RMM.

  @retval RETURN_SUCCESS                Success.
  @retval RETURN_UNSUPPORTED            The execution context is not a Realm.
  @retval RETURN_INCOMPATIBLE_VERSION   The Firmware and RMM specification
                                        revisions are not compatible.
  @retval RETURN_INVALID_PARAMETER      A parameter is invalid.
**/
RETURN_STATUS
EFIAPI
ArmCcaRsiGetVersion (
  OUT UINT32 *CONST  UefiImpl,
  OUT UINT32 *CONST  RmmImplLow,
  OUT UINT32 *CONST  RmmImplHigh
  );

/**
  Get the features supported by the RSI implementation.

  RMM implementations across different CCA platforms may support
  disparate features and may offer disparate configuration options
  for Realms. The features supported by an RSI implementation are
  discovered by reading feature pseudo-register values using the
  RSI_FEATURES command.

  @param [in]   FeatureRegIndex    The Feature Register Index.
  @param [out]  FeatureRegValue    The Feature Register Value.

  @retval RETURN_SUCCESS            Success.
  @retval RETURN_INVALID_PARAMETER  A parameter is invalid.
**/
RETURN_STATUS
EFIAPI
ArmCcaRsiGetFeatures (
  IN    UINT64  FeatureRegIndex,
  OUT   UINT64  *FeatureRegValue
  );