/*
 * Copyright (C) 2022 Huawei Technologies Co., Ltd.
 * Decription: declarations for ffa functions and useful macros
 *
 * This software is licensed under the terms of the GNU General Public
 * License version 2, as published by the Free Software Foundation, and
 * may be copied, distributed, and modified under those terms.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 * GNU General Public License for more details.
 */
#ifndef FFA_ABI_H
#define FFA_ABI_H

#include <linux/arm_ffa.h>
#include "smc_smp.h"
#include "smc_call.h"
/*
 * Normal world sends requests with FFA_MSG_SEND_DIRECT_REQ and
 * responses are returned with FFA_MSG_SEND_DIRECT_RESP for normal
 * messages.
 *
 * All requests with FFA_MSG_SEND_DIRECT_REQ and FFA_MSG_SEND_DIRECT_RESP
 * are using the AArch32 SMC calling convention with register usage as
 * defined in FF-A specification:
 * w0:	Function ID (0x8400006F or 0x84000070)
 * w1:	Source/Destination IDs
 * w2:	Reserved (MBZ)
 * w3-w7: Implementation defined, free to be used below
 */

#define TZ_FFA_VERSION_MAJOR 1
#define TZ_FFA_VERSION_MINOR 0

#define TZ_FFA_BLOCKING_CALL(id)	(id)
#define TZ_FFA_YIELDING_CALL_BIT	31
#define TZ_FFA_YIELDING_CALL(id)	((id) | BIT(TZ_FFA_YIELDING_CALL_BIT))

/*
 * Returns the API version implemented, currently follows the FF-A version.
 * Call register usage:
 * w3:	Service ID, TZ_FFA_GET_API_VERSION
 * w4-w7: Not used (MBZ)
 *
 * Return register usage:
 * w3:	TZ_FFA_VERSION_MAJOR
 * w4:	TZ_FFA_VERSION_MINOR
 * w5-w7: Not used (MBZ)
 */
#define TZ_FFA_GET_API_VERSION TZ_FFA_BLOCKING_CALL(0)

/*
 * Returns the revision of iTrustee
 *
 * Used by non-secure world to figure out which version of the Trusted OS
 * is installed. Note that the returned revision is the revision of the
 * Trusted OS, not of the API.
 *
 * Call register usage:
 * w3:	Service ID, TZ_FFA_GET_OS_VERSION
 * w4-w7: Unused (MBZ)
 *
 * Return register usage:
 * w3:	CFG_TZ_REVISION_MAJOR
 * w4:	CFG_TZ_REVISION_MINOR
 * w5:	TEE_IMPL_GIT_SHA1 (or zero if not supported)
 */
#define TZ_FFA_GET_OS_VERSION	TZ_FFA_BLOCKING_CALL(1)

/*
 * Exchange capabilities between normal world and secure world.
 *
 * Currently, there are no defined capabilities. When features are added new
 * capabilities may be added.
 *
 * Call register usage:
 * w3:	Service ID, TZ_FFA_EXCHANGE_CAPABILITIES
 * w4-w7: Not used (MBZ)
 *
 * Return register usage:
 * w3:	Error code, 0 on success
 * w4:	Bit[7:0]:  Number of parameters needed for RPC to be supplied
 *				   as the second MSG arg struct for
 *				   TZ_FFA_YIELDING_CALL_WITH_ARG.
 *		Bit[31:8]: Reserved (MBZ)
 * w5-w7: Not used (MBZ)
 */
#define TZ_FFA_EXCHANGE_CAPABILITIES TZ_FFA_BLOCKING_CALL(2)

/*
 * Unregister shared memory
 *
 * Call register usage:
 * w3:	Service ID, TZ_FFA_YIELDING_CALL_UNREGISTER_SHM
 * w4:	Shared memory handle, lower bits
 * w5:	Shared memory handle, higher bits
 * w6-w7: Not used (MBZ)
 *
 * Return register usage:
 * w3:	Error code, 0 on success
 * w4-w7: Not used (MBZ)
 */
#define TZ_FFA_UNREGISTER_SHM	TZ_FFA_BLOCKING_CALL(3)

/*
 * Call with struct TZ_msg_arg as argument in the supplied shared memory
 * with a zero internal offset and normal cached memory attributes
 * Register usage:
 * w3:	Service ID, TZ_FFA_YIELDING_CALL_WITH_ARG
 * w4:	Lower 32 bits of a 64-bit Shared memory handle
 * w5:	Upper 32 bits of a 64-bit Shared memory handle
 * w6:	Offset into shared memory pointing to a struct TZ_msg_arg
 *		right after the parameters of this struct (at offset
 *		TZ_MSG_GET_ARG_SIZE(num_params) follows a struct TZ_msg_arg
 *		for RPC, this struct has reserved space for the number of RPC
 *		parameters as returned by TZ_FFA_EXCHANGE_CAPABILITIES.
 * w7:	Not used (MBZ)
 * Resume from RPC. Register usage:
 * w3:	Service ID, TZ_FFA_YIELDING_CALL_RESUME
 * w4-w6: Not used (MBZ)
 * w7:	Resume info
 *
 * Normal return (yielding call is completed). Register usage:
 * w3:	Error code, 0 on success
 * w4:	TZ_FFA_YIELDING_CALL_RETURN_DONE
 * w5-w7: Not used (MBZ)
 *
 * RPC interrupt return (RPC from secure world). Register usage:
 * w3:	Error code == 0
 * w4:	Any defined RPC code but TZ_FFA_YIELDING_CALL_RETURN_DONE
 * w5-w6: Not used (MBZ)
 * w7:	Resume info
 *
 * Possible error codes in register w3:
 * 0:					  Success
 * FFA_DENIED:			  w4 isn't one of TZ_FFA_YIELDING_CALL_START
 *						  TZ_FFA_YIELDING_CALL_RESUME
 *
 * Possible error codes for TZ_FFA_YIELDING_CALL_START
 * FFA_BUSY:			  Number of OP-TEE OS threads exceeded,
 *						  try again later
 * FFA_DENIED:			  RPC shared memory object not found
 * FFA_INVALID_PARAMETER: Bad shared memory handle or offset into the memory
 *
 * Possible error codes for TZ_FFA_YIELDING_CALL_RESUME
 * FFA_INVALID_PARAMETER: Bad resume info
 */
#define TZ_FFA_YIELDING_CALL_WITH_ARG TZ_FFA_YIELDING_CALL(0)
#define TZ_FFA_YIELDING_CALL_RESUME TZ_FFA_YIELDING_CALL(1)

#define TZ_FFA_YIELDING_CALL_RETURN_DONE 0
#define TZ_FFA_YIELDING_CALL_RETURN_RPC_CMD 1
#define TZ_FFA_YIELDING_CALL_RETURN_INTERRUPT 2

int ffa_abi_register(void);
void ffa_abi_unregister(void);
int ffa_forward_call(struct smc_in_params *in_param, struct smc_out_params *out_param, uint8_t wait);

#endif