/* SPDX-License-Identifier: MIT */

/*
 * Copyright 2019 Advanced Micro Devices, Inc.
 */

#ifndef AMDTEE_PRIVATE_H
#define AMDTEE_PRIVATE_H

#include <linux/mutex.h>
#include <linux/spinlock.h>
#include <linux/tee_core.h>
#include <linux/kref.h>
#include <linux/types.h>
#include "amdtee_if.h"

#define DRIVER_NAME     "amdtee"
#define DRIVER_AUTHOR   "AMD-TEE Linux driver team"

/* Some GlobalPlatform error codes used in this driver */
#define TEEC_SUCCESS                    0x00000000
#define TEEC_ERROR_GENERIC              0xFFFF0000
#define TEEC_ERROR_BAD_PARAMETERS       0xFFFF0006
#define TEEC_ERROR_OUT_OF_MEMORY        0xFFFF000C
#define TEEC_ERROR_COMMUNICATION        0xFFFF000E

#define TEEC_ORIGIN_COMMS               0x00000002

/* Maximum number of sessions which can be opened with a Trusted Application */
#define TEE_NUM_SESSIONS                        32

#define TA_LOAD_PATH                            "/amdtee"
#define TA_PATH_MAX                             60

/**
 * struct amdtee - main service struct
 * @teedev:             client device
 * @pool:               shared memory pool
 */
struct amdtee {
        struct tee_device *teedev;
        struct tee_shm_pool *pool;
};

/**
 * struct amdtee_session - Trusted Application (TA) session related information.
 * @ta_handle:     handle to Trusted Application (TA) loaded in TEE environment
 * @refcount:      counter to keep track of sessions opened for the TA instance
 * @session_info:  an array pointing to TA allocated session data.
 * @sess_mask:     session usage bit-mask. If a particular bit is set, then the
 *                 corresponding @session_info entry is in use or valid.
 *
 * Session structure is updated on open_session and this information is used for
 * subsequent operations with the Trusted Application.
 */
struct amdtee_session {
        struct list_head list_node;
        u32 ta_handle;
        struct kref refcount;
        u32 session_info[TEE_NUM_SESSIONS];
        DECLARE_BITMAP(sess_mask, TEE_NUM_SESSIONS);
        spinlock_t lock;        /* synchronizes access to @sess_mask */
};

/**
 * struct amdtee_context_data - AMD-TEE driver context data
 * @sess_list:    Keeps track of sessions opened in current TEE context
 * @shm_list:     Keeps track of buffers allocated and mapped in current TEE
 *                context
 */
struct amdtee_context_data {
        struct list_head sess_list;
        struct list_head shm_list;
        struct mutex shm_mutex;   /* synchronizes access to @shm_list */
};

struct amdtee_driver_data {
        struct amdtee *amdtee;
};

struct shmem_desc {
        void *kaddr;
        u64 size;
};

/**
 * struct amdtee_shm_data - Shared memory data
 * @kaddr:      Kernel virtual address of shared memory
 * @buf_id:     Buffer id of memory mapped by TEE_CMD_ID_MAP_SHARED_MEM
 */
struct amdtee_shm_data {
        struct  list_head shm_node;
        void    *kaddr;
        u32     buf_id;
};

/**
 * struct amdtee_ta_data - Keeps track of all TAs loaded in AMD Secure
 *                         Processor
 * @ta_handle:  Handle to TA loaded in TEE
 * @refcount:   Reference count for the loaded TA
 */
struct amdtee_ta_data {
        struct list_head list_node;
        u32 ta_handle;
        u32 refcount;
};

#define LOWER_TWO_BYTE_MASK     0x0000FFFF

/**
 * set_session_id() - Sets the session identifier.
 * @ta_handle:      [in] handle of the loaded Trusted Application (TA)
 * @session_index:  [in] Session index. Range: 0 to (TEE_NUM_SESSIONS - 1).
 * @session:        [out] Pointer to session id
 *
 * Lower two bytes of the session identifier represents the TA handle and the
 * upper two bytes is session index.
 */
static inline void set_session_id(u32 ta_handle, u32 session_index,
                                  u32 *session)
{
        *session = (session_index << 16) | (LOWER_TWO_BYTE_MASK & ta_handle);
}

static inline u32 get_ta_handle(u32 session)
{
        return session & LOWER_TWO_BYTE_MASK;
}

static inline u32 get_session_index(u32 session)
{
        return (session >> 16) & LOWER_TWO_BYTE_MASK;
}

int amdtee_open_session(struct tee_context *ctx,
                        struct tee_ioctl_open_session_arg *arg,
                        struct tee_param *param);

int amdtee_close_session(struct tee_context *ctx, u32 session);

int amdtee_invoke_func(struct tee_context *ctx,
                       struct tee_ioctl_invoke_arg *arg,
                       struct tee_param *param);

int amdtee_cancel_req(struct tee_context *ctx, u32 cancel_id, u32 session);

int amdtee_map_shmem(struct tee_shm *shm);

void amdtee_unmap_shmem(struct tee_shm *shm);

int handle_load_ta(void *data, u32 size,
                   struct tee_ioctl_open_session_arg *arg);

int handle_unload_ta(u32 ta_handle);

int handle_open_session(struct tee_ioctl_open_session_arg *arg, u32 *info,
                        struct tee_param *p);

int handle_close_session(u32 ta_handle, u32 info);

int handle_map_shmem(u32 count, struct shmem_desc *start, u32 *buf_id);

void handle_unmap_shmem(u32 buf_id);

int handle_invoke_cmd(struct tee_ioctl_invoke_arg *arg, u32 sinfo,
                      struct tee_param *p);

struct tee_shm_pool *amdtee_config_shm(void);

u32 get_buffer_id(struct tee_shm *shm);
#endif /*AMDTEE_PRIVATE_H*/