drivers/crypto/ccp/tee-dev.h

   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__ */