1/* SPDX-License-Identifier: MIT */
  2/*
  3 * Copyright (C) 2019,2021 Advanced Micro Devices, Inc.
  4 *
  5 * Author: Rijo Thomas <Rijo-john.Thomas@amd.com>
  6 * Author: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
  7 *
  8 */
  9
 10/* This file describes the TEE communication interface between host and AMD
 11 * Secure Processor
 12 */
 13
 14#ifndef __TEE_DEV_H__
 15#define __TEE_DEV_H__
 16
 17#include <linux/device.h>
 18#include <linux/mutex.h>
 19
 20#define TEE_DEFAULT_CMD_TIMEOUT		(10 * MSEC_PER_SEC)
 21#define TEE_DEFAULT_RING_TIMEOUT	10
 22#define MAX_BUFFER_SIZE			988
 23
 24/**
 25 * struct tee_init_ring_cmd - Command to init TEE ring buffer
 26 * @low_addr:  bits [31:0] of the physical address of ring buffer
 27 * @hi_addr:   bits [63:32] of the physical address of ring buffer
 28 * @size:      size of ring buffer in bytes
 29 */
 30struct tee_init_ring_cmd {
 31	u32 low_addr;
 32	u32 hi_addr;
 33	u32 size;
 34};
 35
 36#define MAX_RING_BUFFER_ENTRIES		32
 37
 38/**
 39 * struct ring_buf_manager - Helper structure to manage ring buffer.
 40 * @ring_start:  starting address of ring buffer
 41 * @ring_size:   size of ring buffer in bytes
 42 * @ring_pa:     physical address of ring buffer
 43 * @wptr:        index to the last written entry in ring buffer
 44 */
 45struct ring_buf_manager {
 46	struct mutex mutex;	/* synchronizes access to ring buffer */
 47	void *ring_start;
 48	u32 ring_size;
 49	phys_addr_t ring_pa;
 50	u32 wptr;
 51};
 52
 53struct psp_tee_device {
 54	struct device *dev;
 55	struct psp_device *psp;
 56	void __iomem *io_regs;
 57	struct tee_vdata *vdata;
 58	struct ring_buf_manager rb_mgr;
 59};
 60
 61/**
 62 * enum tee_cmd_state - TEE command states for the ring buffer interface
 63 * @TEE_CMD_STATE_INIT:      initial state of command when sent from host
 64 * @TEE_CMD_STATE_PROCESS:   command being processed by TEE environment
 65 * @TEE_CMD_STATE_COMPLETED: command processing completed
 66 */
 67enum tee_cmd_state {
 68	TEE_CMD_STATE_INIT,
 69	TEE_CMD_STATE_PROCESS,
 70	TEE_CMD_STATE_COMPLETED,
 71};
 72
 73/**
 74 * enum cmd_resp_state - TEE command's response status maintained by driver
 75 * @CMD_RESPONSE_INVALID:      initial state when no command is written to ring
 76 * @CMD_WAITING_FOR_RESPONSE:  driver waiting for response from TEE
 77 * @CMD_RESPONSE_TIMEDOUT:     failed to get response from TEE
 78 * @CMD_RESPONSE_COPIED:       driver has copied response from TEE
 79 */
 80enum cmd_resp_state {
 81	CMD_RESPONSE_INVALID,
 82	CMD_WAITING_FOR_RESPONSE,
 83	CMD_RESPONSE_TIMEDOUT,
 84	CMD_RESPONSE_COPIED,
 85};
 86
 87/**
 88 * struct tee_ring_cmd - Structure of the command buffer in TEE ring
 89 * @cmd_id:      refers to &enum tee_cmd_id. Command id for the ring buffer
 90 *               interface
 91 * @cmd_state:   refers to &enum tee_cmd_state
 92 * @status:      status of TEE command execution
 93 * @res0:        reserved region
 94 * @pdata:       private data (currently unused)
 95 * @res1:        reserved region
 96 * @buf:         TEE command specific buffer
 97 * @flag:	 refers to &enum cmd_resp_state
 98 */
 99struct tee_ring_cmd {
100	u32 cmd_id;
101	u32 cmd_state;
102	u32 status;
103	u32 res0[1];
104	u64 pdata;
105	u32 res1[2];
106	u8 buf[MAX_BUFFER_SIZE];
107	u32 flag;
108
109	/* Total size: 1024 bytes */
110} __packed;
111
112int tee_dev_init(struct psp_device *psp);
113void tee_dev_destroy(struct psp_device *psp);
114
115#endif /* __TEE_DEV_H__ */