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 */ 30 struct 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 */ 45 struct 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 53 struct 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 */ 67 enum 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 */ 80 enum 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 */ 99 struct 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; 111 112 int tee_dev_init(struct psp_device *psp); 113 void tee_dev_destroy(struct psp_device *psp); 114 115 #endif /* __TEE_DEV_H__ */ 116