1/* SPDX-License-Identifier: MIT */
  2/*
  3 * Copyright 2019 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_TIMEOUT		10
 21#define MAX_BUFFER_SIZE			992
 22
 23/**
 24 * enum tee_ring_cmd_id - TEE interface commands for ring buffer configuration
 25 * @TEE_RING_INIT_CMD:		Initialize ring buffer
 26 * @TEE_RING_DESTROY_CMD:	Destroy ring buffer
 27 * @TEE_RING_MAX_CMD:		Maximum command id
 28 */
 29enum tee_ring_cmd_id {
 30	TEE_RING_INIT_CMD		= 0x00010000,
 31	TEE_RING_DESTROY_CMD		= 0x00020000,
 32	TEE_RING_MAX_CMD		= 0x000F0000,
 33};
 34
 35/**
 36 * struct tee_init_ring_cmd - Command to init TEE ring buffer
 37 * @low_addr:  bits [31:0] of the physical address of ring buffer
 38 * @hi_addr:   bits [63:32] of the physical address of ring buffer
 39 * @size:      size of ring buffer in bytes
 40 */
 41struct tee_init_ring_cmd {
 42	u32 low_addr;
 43	u32 hi_addr;
 44	u32 size;
 45};
 46
 47#define MAX_RING_BUFFER_ENTRIES		32
 48
 49/**
 50 * struct ring_buf_manager - Helper structure to manage ring buffer.
 51 * @ring_start:  starting address of ring buffer
 52 * @ring_size:   size of ring buffer in bytes
 53 * @ring_pa:     physical address of ring buffer
 54 * @wptr:        index to the last written entry in ring buffer
 55 */
 56struct ring_buf_manager {
 57	struct mutex mutex;	/* synchronizes access to ring buffer */
 58	void *ring_start;
 59	u32 ring_size;
 60	phys_addr_t ring_pa;
 61	u32 wptr;
 62};
 63
 64struct psp_tee_device {
 65	struct device *dev;
 66	struct psp_device *psp;
 67	void __iomem *io_regs;
 68	struct tee_vdata *vdata;
 69	struct ring_buf_manager rb_mgr;
 70};
 71
 72/**
 73 * enum tee_cmd_state - TEE command states for the ring buffer interface
 74 * @TEE_CMD_STATE_INIT:      initial state of command when sent from host
 75 * @TEE_CMD_STATE_PROCESS:   command being processed by TEE environment
 76 * @TEE_CMD_STATE_COMPLETED: command processing completed
 77 */
 78enum tee_cmd_state {
 79	TEE_CMD_STATE_INIT,
 80	TEE_CMD_STATE_PROCESS,
 81	TEE_CMD_STATE_COMPLETED,
 82};
 83
 84/**
 85 * struct tee_ring_cmd - Structure of the command buffer in TEE ring
 86 * @cmd_id:      refers to &enum tee_cmd_id. Command id for the ring buffer
 87 *               interface
 88 * @cmd_state:   refers to &enum tee_cmd_state
 89 * @status:      status of TEE command execution
 90 * @res0:        reserved region
 91 * @pdata:       private data (currently unused)
 92 * @res1:        reserved region
 93 * @buf:         TEE command specific buffer
 94 */
 95struct tee_ring_cmd {
 96	u32 cmd_id;
 97	u32 cmd_state;
 98	u32 status;
 99	u32 res0[1];
100	u64 pdata;
101	u32 res1[2];
102	u8 buf[MAX_BUFFER_SIZE];
103
104	/* Total size: 1024 bytes */
105} __packed;
106
107int tee_dev_init(struct psp_device *psp);
108void tee_dev_destroy(struct psp_device *psp);
109
110#endif /* __TEE_DEV_H__ */