crypto/ccp/tee-dev.h

0001 /* SPDX-License-Identifier: MIT */
0002 /*
0003  * Copyright (C) 2019,2021 Advanced Micro Devices, Inc.
0004  *
0005  * Author: Rijo Thomas <Rijo-john.Thomas@amd.com>
0006  * Author: Devaraj Rangasamy <Devaraj.Rangasamy@amd.com>
0007  *
0008  */
0009
0010 /* This file describes the TEE communication interface between host and AMD
0011  * Secure Processor
0012  */
0013
0014 #ifndef __TEE_DEV_H__
0015 #define __TEE_DEV_H__
0016
0017 #include <linux/device.h>
0018 #include <linux/mutex.h>
0019
0020 #define TEE_DEFAULT_TIMEOUT     10
0021 #define MAX_BUFFER_SIZE         988
0022
0023 /**
0024  * enum tee_ring_cmd_id - TEE interface commands for ring buffer configuration
0025  * @TEE_RING_INIT_CMD:      Initialize ring buffer
0026  * @TEE_RING_DESTROY_CMD:   Destroy ring buffer
0027  * @TEE_RING_MAX_CMD:       Maximum command id
0028  */
0029 enum tee_ring_cmd_id {
0030     TEE_RING_INIT_CMD       = 0x00010000,
0031     TEE_RING_DESTROY_CMD        = 0x00020000,
0032     TEE_RING_MAX_CMD        = 0x000F0000,
0033 };
0034
0035 /**
0036  * struct tee_init_ring_cmd - Command to init TEE ring buffer
0037  * @low_addr:  bits [31:0] of the physical address of ring buffer
0038  * @hi_addr:   bits [63:32] of the physical address of ring buffer
0039  * @size:      size of ring buffer in bytes
0040  */
0041 struct tee_init_ring_cmd {
0042     u32 low_addr;
0043     u32 hi_addr;
0044     u32 size;
0045 };
0046
0047 #define MAX_RING_BUFFER_ENTRIES     32
0048
0049 /**
0050  * struct ring_buf_manager - Helper structure to manage ring buffer.
0051  * @ring_start:  starting address of ring buffer
0052  * @ring_size:   size of ring buffer in bytes
0053  * @ring_pa:     physical address of ring buffer
0054  * @wptr:        index to the last written entry in ring buffer
0055  */
0056 struct ring_buf_manager {
0057     struct mutex mutex; /* synchronizes access to ring buffer */
0058     void *ring_start;
0059     u32 ring_size;
0060     phys_addr_t ring_pa;
0061     u32 wptr;
0062 };
0063
0064 struct psp_tee_device {
0065     struct device *dev;
0066     struct psp_device *psp;
0067     void __iomem *io_regs;
0068     struct tee_vdata *vdata;
0069     struct ring_buf_manager rb_mgr;
0070 };
0071
0072 /**
0073  * enum tee_cmd_state - TEE command states for the ring buffer interface
0074  * @TEE_CMD_STATE_INIT:      initial state of command when sent from host
0075  * @TEE_CMD_STATE_PROCESS:   command being processed by TEE environment
0076  * @TEE_CMD_STATE_COMPLETED: command processing completed
0077  */
0078 enum tee_cmd_state {
0079     TEE_CMD_STATE_INIT,
0080     TEE_CMD_STATE_PROCESS,
0081     TEE_CMD_STATE_COMPLETED,
0082 };
0083
0084 /**
0085  * enum cmd_resp_state - TEE command's response status maintained by driver
0086  * @CMD_RESPONSE_INVALID:      initial state when no command is written to ring
0087  * @CMD_WAITING_FOR_RESPONSE:  driver waiting for response from TEE
0088  * @CMD_RESPONSE_TIMEDOUT:     failed to get response from TEE
0089  * @CMD_RESPONSE_COPIED:       driver has copied response from TEE
0090  */
0091 enum cmd_resp_state {
0092     CMD_RESPONSE_INVALID,
0093     CMD_WAITING_FOR_RESPONSE,
0094     CMD_RESPONSE_TIMEDOUT,
0095     CMD_RESPONSE_COPIED,
0096 };
0097
0098 /**
0099  * struct tee_ring_cmd - Structure of the command buffer in TEE ring
0100  * @cmd_id:      refers to &enum tee_cmd_id. Command id for the ring buffer
0101  *               interface
0102  * @cmd_state:   refers to &enum tee_cmd_state
0103  * @status:      status of TEE command execution
0104  * @res0:        reserved region
0105  * @pdata:       private data (currently unused)
0106  * @res1:        reserved region
0107  * @buf:         TEE command specific buffer
0108  * @flag:    refers to &enum cmd_resp_state
0109  */
0110 struct tee_ring_cmd {
0111     u32 cmd_id;
0112     u32 cmd_state;
0113     u32 status;
0114     u32 res0[1];
0115     u64 pdata;
0116     u32 res1[2];
0117     u8 buf[MAX_BUFFER_SIZE];
0118     u32 flag;
0119
0120     /* Total size: 1024 bytes */
0121 } __packed;
0122
0123 int tee_dev_init(struct psp_device *psp);
0124 void tee_dev_destroy(struct psp_device *psp);
0125
0126 #endif /* __TEE_DEV_H__ */