/* SPDX-License-Identifier: BSD-2-Clause */
/*
 * Copyright (c) 2015-2018, Linaro Limited
 */

#ifndef OPTEE_SMC_H
#define OPTEE_SMC_H

#include <linux/arm-smccc.h>
#include <linux/bitops.h>

/*
 * This file is based on
 * https://github.com/OP-TEE/optee_os/blob/master/core/arch/arm/include/sm/optee_smc.h
 * and may need to be updated when introducing new features.
 */

#define OPTEE_SMC_STD_CALL_VAL(func_num) \
        ARM_SMCCC_CALL_VAL(ARM_SMCCC_STD_CALL, ARM_SMCCC_SMC_32, \
                           ARM_SMCCC_OWNER_TRUSTED_OS, (func_num))
#define OPTEE_SMC_FAST_CALL_VAL(func_num) \
        ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, ARM_SMCCC_SMC_32, \
                           ARM_SMCCC_OWNER_TRUSTED_OS, (func_num))

/*
 * Function specified by SMC Calling convention.
 */
#define OPTEE_SMC_FUNCID_CALLS_COUNT    0xFF00
#define OPTEE_SMC_CALLS_COUNT \
        ARM_SMCCC_CALL_VAL(OPTEE_SMC_FAST_CALL, SMCCC_SMC_32, \
                           SMCCC_OWNER_TRUSTED_OS_END, \
                           OPTEE_SMC_FUNCID_CALLS_COUNT)

/*
 * Normal cached memory (write-back), shareable for SMP systems and not
 * shareable for UP systems.
 */
#define OPTEE_SMC_SHM_CACHED            1

/*
 * a0..a7 is used as register names in the descriptions below, on arm32
 * that translates to r0..r7 and on arm64 to w0..w7. In both cases it's
 * 32-bit registers.
 */

/*
 * Function specified by SMC Calling convention
 *
 * Return one of the following UIDs if using API specified in this file
 * without further extentions:
 * 65cb6b93-af0c-4617-8ed6-644a8d1140f8
 * see also OPTEE_SMC_UID_* in optee_msg.h
 */
#define OPTEE_SMC_FUNCID_CALLS_UID OPTEE_MSG_FUNCID_CALLS_UID
#define OPTEE_SMC_CALLS_UID \
        ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, ARM_SMCCC_SMC_32, \
                           ARM_SMCCC_OWNER_TRUSTED_OS_END, \
                           OPTEE_SMC_FUNCID_CALLS_UID)

/*
 * Function specified by SMC Calling convention
 *
 * Returns 2.0 if using API specified in this file without further extentions.
 * see also OPTEE_MSG_REVISION_* in optee_msg.h
 */
#define OPTEE_SMC_FUNCID_CALLS_REVISION OPTEE_MSG_FUNCID_CALLS_REVISION
#define OPTEE_SMC_CALLS_REVISION \
        ARM_SMCCC_CALL_VAL(ARM_SMCCC_FAST_CALL, ARM_SMCCC_SMC_32, \
                           ARM_SMCCC_OWNER_TRUSTED_OS_END, \
                           OPTEE_SMC_FUNCID_CALLS_REVISION)

struct optee_smc_calls_revision_result {
        unsigned long major;
        unsigned long minor;
        unsigned long reserved0;
        unsigned long reserved1;
};

/*
 * Get UUID of Trusted OS.
 *
 * Used by non-secure world to figure out which Trusted OS is installed.
 * Note that returned UUID is the UUID of the Trusted OS, not of the API.
 *
 * Returns UUID in a0-4 in the same way as OPTEE_SMC_CALLS_UID
 * described above.
 */
#define OPTEE_SMC_FUNCID_GET_OS_UUID OPTEE_MSG_FUNCID_GET_OS_UUID
#define OPTEE_SMC_CALL_GET_OS_UUID \
        OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_GET_OS_UUID)

/*
 * Get revision of Trusted OS.
 *
 * Used by non-secure world to figure out which version of the Trusted OS
 * is installed. Note that the returned revision is the revision of the
 * Trusted OS, not of the API.
 *
 * Returns revision in a0-1 in the same way as OPTEE_SMC_CALLS_REVISION
 * described above. May optionally return a 32-bit build identifier in a2,
 * with zero meaning unspecified.
 */
#define OPTEE_SMC_FUNCID_GET_OS_REVISION OPTEE_MSG_FUNCID_GET_OS_REVISION
#define OPTEE_SMC_CALL_GET_OS_REVISION \
        OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_GET_OS_REVISION)

struct optee_smc_call_get_os_revision_result {
        unsigned long major;
        unsigned long minor;
        unsigned long build_id;
        unsigned long reserved1;
};

/*
 * Call with struct optee_msg_arg as argument
 *
 * Call register usage:
 * a0   SMC Function ID, OPTEE_SMC*CALL_WITH_ARG
 * a1   Upper 32bit of a 64bit physical pointer to a struct optee_msg_arg
 * a2   Lower 32bit of a 64bit physical pointer to a struct optee_msg_arg
 * a3   Cache settings, not used if physical pointer is in a predefined shared
 *      memory area else per OPTEE_SMC_SHM_*
 * a4-6 Not used
 * a7   Hypervisor Client ID register
 *
 * Normal return register usage:
 * a0   Return value, OPTEE_SMC_RETURN_*
 * a1-3 Not used
 * a4-7 Preserved
 *
 * OPTEE_SMC_RETURN_ETHREAD_LIMIT return register usage:
 * a0   Return value, OPTEE_SMC_RETURN_ETHREAD_LIMIT
 * a1-3 Preserved
 * a4-7 Preserved
 *
 * RPC return register usage:
 * a0   Return value, OPTEE_SMC_RETURN_IS_RPC(val)
 * a1-2 RPC parameters
 * a3-7 Resume information, must be preserved
 *
 * Possible return values:
 * OPTEE_SMC_RETURN_UNKNOWN_FUNCTION    Trusted OS does not recognize this
 *                                      function.
 * OPTEE_SMC_RETURN_OK                  Call completed, result updated in
 *                                      the previously supplied struct
 *                                      optee_msg_arg.
 * OPTEE_SMC_RETURN_ETHREAD_LIMIT       Number of Trusted OS threads exceeded,
 *                                      try again later.
 * OPTEE_SMC_RETURN_EBADADDR            Bad physcial pointer to struct
 *                                      optee_msg_arg.
 * OPTEE_SMC_RETURN_EBADCMD             Bad/unknown cmd in struct optee_msg_arg
 * OPTEE_SMC_RETURN_IS_RPC()            Call suspended by RPC call to normal
 *                                      world.
 */
#define OPTEE_SMC_FUNCID_CALL_WITH_ARG OPTEE_MSG_FUNCID_CALL_WITH_ARG
#define OPTEE_SMC_CALL_WITH_ARG \
        OPTEE_SMC_STD_CALL_VAL(OPTEE_SMC_FUNCID_CALL_WITH_ARG)

/*
 * Get Shared Memory Config
 *
 * Returns the Secure/Non-secure shared memory config.
 *
 * Call register usage:
 * a0   SMC Function ID, OPTEE_SMC_GET_SHM_CONFIG
 * a1-6 Not used
 * a7   Hypervisor Client ID register
 *
 * Have config return register usage:
 * a0   OPTEE_SMC_RETURN_OK
 * a1   Physical address of start of SHM
 * a2   Size of of SHM
 * a3   Cache settings of memory, as defined by the
 *      OPTEE_SMC_SHM_* values above
 * a4-7 Preserved
 *
 * Not available register usage:
 * a0   OPTEE_SMC_RETURN_ENOTAVAIL
 * a1-3 Not used
 * a4-7 Preserved
 */
#define OPTEE_SMC_FUNCID_GET_SHM_CONFIG 7
#define OPTEE_SMC_GET_SHM_CONFIG \
        OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_GET_SHM_CONFIG)

struct optee_smc_get_shm_config_result {
        unsigned long status;
        unsigned long start;
        unsigned long size;
        unsigned long settings;
};

/*
 * Exchanges capabilities between normal world and secure world
 *
 * Call register usage:
 * a0   SMC Function ID, OPTEE_SMC_EXCHANGE_CAPABILITIES
 * a1   bitfield of normal world capabilities OPTEE_SMC_NSEC_CAP_*
 * a2-6 Not used
 * a7   Hypervisor Client ID register
 *
 * Normal return register usage:
 * a0   OPTEE_SMC_RETURN_OK
 * a1   bitfield of secure world capabilities OPTEE_SMC_SEC_CAP_*
 * a2-7 Preserved
 *
 * Error return register usage:
 * a0   OPTEE_SMC_RETURN_ENOTAVAIL, can't use the capabilities from normal world
 * a1   bitfield of secure world capabilities OPTEE_SMC_SEC_CAP_*
 * a2-7 Preserved
 */
/* Normal world works as a uniprocessor system */
#define OPTEE_SMC_NSEC_CAP_UNIPROCESSOR         BIT(0)
/* Secure world has reserved shared memory for normal world to use */
#define OPTEE_SMC_SEC_CAP_HAVE_RESERVED_SHM     BIT(0)
/* Secure world can communicate via previously unregistered shared memory */
#define OPTEE_SMC_SEC_CAP_UNREGISTERED_SHM      BIT(1)

/*
 * Secure world supports commands "register/unregister shared memory",
 * secure world accepts command buffers located in any parts of non-secure RAM
 */
#define OPTEE_SMC_SEC_CAP_DYNAMIC_SHM           BIT(2)

#define OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES  9
#define OPTEE_SMC_EXCHANGE_CAPABILITIES \
        OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_EXCHANGE_CAPABILITIES)

struct optee_smc_exchange_capabilities_result {
        unsigned long status;
        unsigned long capabilities;
        unsigned long reserved0;
        unsigned long reserved1;
};

/*
 * Disable and empties cache of shared memory objects
 *
 * Secure world can cache frequently used shared memory objects, for
 * example objects used as RPC arguments. When secure world is idle this
 * function returns one shared memory reference to free. To disable the
 * cache and free all cached objects this function has to be called until
 * it returns OPTEE_SMC_RETURN_ENOTAVAIL.
 *
 * Call register usage:
 * a0   SMC Function ID, OPTEE_SMC_DISABLE_SHM_CACHE
 * a1-6 Not used
 * a7   Hypervisor Client ID register
 *
 * Normal return register usage:
 * a0   OPTEE_SMC_RETURN_OK
 * a1   Upper 32bit of a 64bit Shared memory cookie
 * a2   Lower 32bit of a 64bit Shared memory cookie
 * a3-7 Preserved
 *
 * Cache empty return register usage:
 * a0   OPTEE_SMC_RETURN_ENOTAVAIL
 * a1-7 Preserved
 *
 * Not idle return register usage:
 * a0   OPTEE_SMC_RETURN_EBUSY
 * a1-7 Preserved
 */
#define OPTEE_SMC_FUNCID_DISABLE_SHM_CACHE      10
#define OPTEE_SMC_DISABLE_SHM_CACHE \
        OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_DISABLE_SHM_CACHE)

struct optee_smc_disable_shm_cache_result {
        unsigned long status;
        unsigned long shm_upper32;
        unsigned long shm_lower32;
        unsigned long reserved0;
};

/*
 * Enable cache of shared memory objects
 *
 * Secure world can cache frequently used shared memory objects, for
 * example objects used as RPC arguments. When secure world is idle this
 * function returns OPTEE_SMC_RETURN_OK and the cache is enabled. If
 * secure world isn't idle OPTEE_SMC_RETURN_EBUSY is returned.
 *
 * Call register usage:
 * a0   SMC Function ID, OPTEE_SMC_ENABLE_SHM_CACHE
 * a1-6 Not used
 * a7   Hypervisor Client ID register
 *
 * Normal return register usage:
 * a0   OPTEE_SMC_RETURN_OK
 * a1-7 Preserved
 *
 * Not idle return register usage:
 * a0   OPTEE_SMC_RETURN_EBUSY
 * a1-7 Preserved
 */
#define OPTEE_SMC_FUNCID_ENABLE_SHM_CACHE       11
#define OPTEE_SMC_ENABLE_SHM_CACHE \
        OPTEE_SMC_FAST_CALL_VAL(OPTEE_SMC_FUNCID_ENABLE_SHM_CACHE)

/*
 * Resume from RPC (for example after processing a foreign interrupt)
 *
 * Call register usage:
 * a0   SMC Function ID, OPTEE_SMC_CALL_RETURN_FROM_RPC
 * a1-3 Value of a1-3 when OPTEE_SMC_CALL_WITH_ARG returned
 *      OPTEE_SMC_RETURN_RPC in a0
 *
 * Return register usage is the same as for OPTEE_SMC_*CALL_WITH_ARG above.
 *
 * Possible return values
 * OPTEE_SMC_RETURN_UNKNOWN_FUNCTION    Trusted OS does not recognize this
 *                                      function.
 * OPTEE_SMC_RETURN_OK                  Original call completed, result
 *                                      updated in the previously supplied.
 *                                      struct optee_msg_arg
 * OPTEE_SMC_RETURN_RPC                 Call suspended by RPC call to normal
 *                                      world.
 * OPTEE_SMC_RETURN_ERESUME             Resume failed, the opaque resume
 *                                      information was corrupt.
 */
#define OPTEE_SMC_FUNCID_RETURN_FROM_RPC        3
#define OPTEE_SMC_CALL_RETURN_FROM_RPC \
        OPTEE_SMC_STD_CALL_VAL(OPTEE_SMC_FUNCID_RETURN_FROM_RPC)

#define OPTEE_SMC_RETURN_RPC_PREFIX_MASK        0xFFFF0000
#define OPTEE_SMC_RETURN_RPC_PREFIX             0xFFFF0000
#define OPTEE_SMC_RETURN_RPC_FUNC_MASK          0x0000FFFF

#define OPTEE_SMC_RETURN_GET_RPC_FUNC(ret) \
        ((ret) & OPTEE_SMC_RETURN_RPC_FUNC_MASK)

#define OPTEE_SMC_RPC_VAL(func)         ((func) | OPTEE_SMC_RETURN_RPC_PREFIX)

/*
 * Allocate memory for RPC parameter passing. The memory is used to hold a
 * struct optee_msg_arg.
 *
 * "Call" register usage:
 * a0   This value, OPTEE_SMC_RETURN_RPC_ALLOC
 * a1   Size in bytes of required argument memory
 * a2   Not used
 * a3   Resume information, must be preserved
 * a4-5 Not used
 * a6-7 Resume information, must be preserved
 *
 * "Return" register usage:
 * a0   SMC Function ID, OPTEE_SMC_CALL_RETURN_FROM_RPC.
 * a1   Upper 32bits of 64bit physical pointer to allocated
 *      memory, (a1 == 0 && a2 == 0) if size was 0 or if memory can't
 *      be allocated.
 * a2   Lower 32bits of 64bit physical pointer to allocated
 *      memory, (a1 == 0 && a2 == 0) if size was 0 or if memory can't
 *      be allocated
 * a3   Preserved
 * a4   Upper 32bits of 64bit Shared memory cookie used when freeing
 *      the memory or doing an RPC
 * a5   Lower 32bits of 64bit Shared memory cookie used when freeing
 *      the memory or doing an RPC
 * a6-7 Preserved
 */
#define OPTEE_SMC_RPC_FUNC_ALLOC        0
#define OPTEE_SMC_RETURN_RPC_ALLOC \
        OPTEE_SMC_RPC_VAL(OPTEE_SMC_RPC_FUNC_ALLOC)

/*
 * Free memory previously allocated by OPTEE_SMC_RETURN_RPC_ALLOC
 *
 * "Call" register usage:
 * a0   This value, OPTEE_SMC_RETURN_RPC_FREE
 * a1   Upper 32bits of 64bit shared memory cookie belonging to this
 *      argument memory
 * a2   Lower 32bits of 64bit shared memory cookie belonging to this
 *      argument memory
 * a3-7 Resume information, must be preserved
 *
 * "Return" register usage:
 * a0   SMC Function ID, OPTEE_SMC_CALL_RETURN_FROM_RPC.
 * a1-2 Not used
 * a3-7 Preserved
 */
#define OPTEE_SMC_RPC_FUNC_FREE         2
#define OPTEE_SMC_RETURN_RPC_FREE \
        OPTEE_SMC_RPC_VAL(OPTEE_SMC_RPC_FUNC_FREE)

/*
 * Deliver foreign interrupt to normal world.
 *
 * "Call" register usage:
 * a0   OPTEE_SMC_RETURN_RPC_FOREIGN_INTR
 * a1-7 Resume information, must be preserved
 *
 * "Return" register usage:
 * a0   SMC Function ID, OPTEE_SMC_CALL_RETURN_FROM_RPC.
 * a1-7 Preserved
 */
#define OPTEE_SMC_RPC_FUNC_FOREIGN_INTR         4
#define OPTEE_SMC_RETURN_RPC_FOREIGN_INTR \
        OPTEE_SMC_RPC_VAL(OPTEE_SMC_RPC_FUNC_FOREIGN_INTR)

/*
 * Do an RPC request. The supplied struct optee_msg_arg tells which
 * request to do and the parameters for the request. The following fields
 * are used (the rest are unused):
 * - cmd                the Request ID
 * - ret                return value of the request, filled in by normal world
 * - num_params         number of parameters for the request
 * - params             the parameters
 * - param_attrs        attributes of the parameters
 *
 * "Call" register usage:
 * a0   OPTEE_SMC_RETURN_RPC_CMD
 * a1   Upper 32bit of a 64bit Shared memory cookie holding a
 *      struct optee_msg_arg, must be preserved, only the data should
 *      be updated
 * a2   Lower 32bit of a 64bit Shared memory cookie holding a
 *      struct optee_msg_arg, must be preserved, only the data should
 *      be updated
 * a3-7 Resume information, must be preserved
 *
 * "Return" register usage:
 * a0   SMC Function ID, OPTEE_SMC_CALL_RETURN_FROM_RPC.
 * a1-2 Not used
 * a3-7 Preserved
 */
#define OPTEE_SMC_RPC_FUNC_CMD          5
#define OPTEE_SMC_RETURN_RPC_CMD \
        OPTEE_SMC_RPC_VAL(OPTEE_SMC_RPC_FUNC_CMD)

/* Returned in a0 */
#define OPTEE_SMC_RETURN_UNKNOWN_FUNCTION 0xFFFFFFFF

/* Returned in a0 only from Trusted OS functions */
#define OPTEE_SMC_RETURN_OK             0x0
#define OPTEE_SMC_RETURN_ETHREAD_LIMIT  0x1
#define OPTEE_SMC_RETURN_EBUSY          0x2
#define OPTEE_SMC_RETURN_ERESUME        0x3
#define OPTEE_SMC_RETURN_EBADADDR       0x4
#define OPTEE_SMC_RETURN_EBADCMD        0x5
#define OPTEE_SMC_RETURN_ENOMEM         0x6
#define OPTEE_SMC_RETURN_ENOTAVAIL      0x7
#define OPTEE_SMC_RETURN_IS_RPC(ret)    __optee_smc_return_is_rpc((ret))

static inline bool __optee_smc_return_is_rpc(u32 ret)
{
        return ret != OPTEE_SMC_RETURN_UNKNOWN_FUNCTION &&
               (ret & OPTEE_SMC_RETURN_RPC_PREFIX_MASK) ==
                        OPTEE_SMC_RETURN_RPC_PREFIX;
}

#endif /* OPTEE_SMC_H */