// SPDX-License-Identifier: MIT
/*
 * Copyright 2019 Advanced Micro Devices, Inc.
 */

#include <linux/device.h>
#include <linux/tee.h>
#include <linux/tee_core.h>
#include <linux/psp-tee.h>
#include <linux/slab.h>
#include <linux/psp.h>
#include "amdtee_if.h"
#include "amdtee_private.h"

static int tee_params_to_amd_params(struct tee_param *tee, u32 count,
                                    struct tee_operation *amd)
{
        int i;
        u32 type;

        if (!count)
                return 0;

        if (!tee || !amd || count > TEE_MAX_PARAMS)
                return -EINVAL;

        amd->param_types = 0;
        for (i = 0; i < count; i++) {
                /* AMD TEE does not support meta parameter */
                if (tee[i].attr > TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT)
                        return -EINVAL;

                amd->param_types |= ((tee[i].attr & 0xF) << i * 4);
        }

        for (i = 0; i < count; i++) {
                type = TEE_PARAM_TYPE_GET(amd->param_types, i);
                pr_debug("%s: type[%d] = 0x%x\n", __func__, i, type);

                if (type == TEE_OP_PARAM_TYPE_INVALID)
                        return -EINVAL;

                if (type == TEE_OP_PARAM_TYPE_NONE)
                        continue;

                /* It is assumed that all values are within 2^32-1 */
                if (type > TEE_OP_PARAM_TYPE_VALUE_INOUT) {
                        u32 buf_id = get_buffer_id(tee[i].u.memref.shm);

                        amd->params[i].mref.buf_id = buf_id;
                        amd->params[i].mref.offset = tee[i].u.memref.shm_offs;
                        amd->params[i].mref.size = tee[i].u.memref.size;
                        pr_debug("%s: bufid[%d] = 0x%x, offset[%d] = 0x%x, size[%d] = 0x%x\n",
                                 __func__,
                                 i, amd->params[i].mref.buf_id,
                                 i, amd->params[i].mref.offset,
                                 i, amd->params[i].mref.size);
                } else {
                        if (tee[i].u.value.c)
                                pr_warn("%s: Discarding value c", __func__);

                        amd->params[i].val.a = tee[i].u.value.a;
                        amd->params[i].val.b = tee[i].u.value.b;
                        pr_debug("%s: a[%d] = 0x%x, b[%d] = 0x%x\n", __func__,
                                 i, amd->params[i].val.a,
                                 i, amd->params[i].val.b);
                }
        }
        return 0;
}

static int amd_params_to_tee_params(struct tee_param *tee, u32 count,
                                    struct tee_operation *amd)
{
        int i;
        u32 type;

        if (!count)
                return 0;

        if (!tee || !amd || count > TEE_MAX_PARAMS)
                return -EINVAL;

        /* Assumes amd->param_types is valid */
        for (i = 0; i < count; i++) {
                type = TEE_PARAM_TYPE_GET(amd->param_types, i);
                pr_debug("%s: type[%d] = 0x%x\n", __func__, i, type);

                if (type == TEE_OP_PARAM_TYPE_INVALID ||
                    type > TEE_OP_PARAM_TYPE_MEMREF_INOUT)
                        return -EINVAL;

                if (type == TEE_OP_PARAM_TYPE_NONE ||
                    type == TEE_OP_PARAM_TYPE_VALUE_INPUT ||
                    type == TEE_OP_PARAM_TYPE_MEMREF_INPUT)
                        continue;

                /*
                 * It is assumed that buf_id remains unchanged for
                 * both open_session and invoke_cmd call
                 */
                if (type > TEE_OP_PARAM_TYPE_MEMREF_INPUT) {
                        tee[i].u.memref.shm_offs = amd->params[i].mref.offset;
                        tee[i].u.memref.size = amd->params[i].mref.size;
                        pr_debug("%s: bufid[%d] = 0x%x, offset[%d] = 0x%x, size[%d] = 0x%x\n",
                                 __func__,
                                 i, amd->params[i].mref.buf_id,
                                 i, amd->params[i].mref.offset,
                                 i, amd->params[i].mref.size);
                } else {
                        /* field 'c' not supported by AMD TEE */
                        tee[i].u.value.a = amd->params[i].val.a;
                        tee[i].u.value.b = amd->params[i].val.b;
                        tee[i].u.value.c = 0;
                        pr_debug("%s: a[%d] = 0x%x, b[%d] = 0x%x\n",
                                 __func__,
                                 i, amd->params[i].val.a,
                                 i, amd->params[i].val.b);
                }
        }
        return 0;
}

static DEFINE_MUTEX(ta_refcount_mutex);
static LIST_HEAD(ta_list);

static u32 get_ta_refcount(u32 ta_handle)
{
        struct amdtee_ta_data *ta_data;
        u32 count = 0;

        /* Caller must hold a mutex */
        list_for_each_entry(ta_data, &ta_list, list_node)
                if (ta_data->ta_handle == ta_handle)
                        return ++ta_data->refcount;

        ta_data = kzalloc_obj(*ta_data);
        if (ta_data) {
                ta_data->ta_handle = ta_handle;
                ta_data->refcount = 1;
                count = ta_data->refcount;
                list_add(&ta_data->list_node, &ta_list);
        }

        return count;
}

static u32 put_ta_refcount(u32 ta_handle)
{
        struct amdtee_ta_data *ta_data;
        u32 count = 0;

        /* Caller must hold a mutex */
        list_for_each_entry(ta_data, &ta_list, list_node)
                if (ta_data->ta_handle == ta_handle) {
                        count = --ta_data->refcount;
                        if (count == 0) {
                                list_del(&ta_data->list_node);
                                kfree(ta_data);
                                break;
                        }
                }

        return count;
}

int handle_unload_ta(u32 ta_handle)
{
        struct tee_cmd_unload_ta cmd = {0};
        u32 status, count;
        int ret;

        if (!ta_handle)
                return -EINVAL;

        mutex_lock(&ta_refcount_mutex);

        count = put_ta_refcount(ta_handle);

        if (count) {
                pr_debug("unload ta: not unloading %u count %u\n",
                         ta_handle, count);
                ret = -EBUSY;
                goto unlock;
        }

        cmd.ta_handle = ta_handle;

        ret = psp_tee_process_cmd(TEE_CMD_ID_UNLOAD_TA, (void *)&cmd,
                                  sizeof(cmd), &status);
        if (!ret && status != 0) {
                pr_err("unload ta: status = 0x%x\n", status);
                ret = -EBUSY;
        } else {
                pr_debug("unloaded ta handle %u\n", ta_handle);
        }

unlock:
        mutex_unlock(&ta_refcount_mutex);
        return ret;
}

int handle_close_session(u32 ta_handle, u32 info)
{
        struct tee_cmd_close_session cmd = {0};
        u32 status;
        int ret;

        if (ta_handle == 0)
                return -EINVAL;

        cmd.ta_handle = ta_handle;
        cmd.session_info = info;

        ret = psp_tee_process_cmd(TEE_CMD_ID_CLOSE_SESSION, (void *)&cmd,
                                  sizeof(cmd), &status);
        if (!ret && status != 0) {
                pr_err("close session: status = 0x%x\n", status);
                ret = -EBUSY;
        }

        return ret;
}

void handle_unmap_shmem(u32 buf_id)
{
        struct tee_cmd_unmap_shared_mem cmd = {0};
        u32 status;
        int ret;

        cmd.buf_id = buf_id;

        ret = psp_tee_process_cmd(TEE_CMD_ID_UNMAP_SHARED_MEM, (void *)&cmd,
                                  sizeof(cmd), &status);
        if (!ret)
                pr_debug("unmap shared memory: buf_id %u status = 0x%x\n",
                         buf_id, status);
}

int handle_invoke_cmd(struct tee_ioctl_invoke_arg *arg, u32 sinfo,
                      struct tee_param *p)
{
        struct tee_cmd_invoke_cmd cmd = {0};
        int ret;

        if (!arg || (!p && arg->num_params))
                return -EINVAL;

        arg->ret_origin = TEEC_ORIGIN_COMMS;

        if (arg->session == 0) {
                arg->ret = TEEC_ERROR_BAD_PARAMETERS;
                return -EINVAL;
        }

        ret = tee_params_to_amd_params(p, arg->num_params, &cmd.op);
        if (ret) {
                pr_err("invalid Params. Abort invoke command\n");
                arg->ret = TEEC_ERROR_BAD_PARAMETERS;
                return ret;
        }

        cmd.ta_handle = get_ta_handle(arg->session);
        cmd.cmd_id = arg->func;
        cmd.session_info = sinfo;

        ret = psp_tee_process_cmd(TEE_CMD_ID_INVOKE_CMD, (void *)&cmd,
                                  sizeof(cmd), &arg->ret);
        if (ret) {
                arg->ret = TEEC_ERROR_COMMUNICATION;
        } else {
                ret = amd_params_to_tee_params(p, arg->num_params, &cmd.op);
                if (unlikely(ret)) {
                        pr_err("invoke command: failed to copy output\n");
                        arg->ret = TEEC_ERROR_GENERIC;
                        return ret;
                }
                arg->ret_origin = cmd.return_origin;
                pr_debug("invoke command: RO = 0x%x ret = 0x%x\n",
                         arg->ret_origin, arg->ret);
        }

        return ret;
}

int handle_map_shmem(u32 count, struct shmem_desc *start, u32 *buf_id)
{
        struct tee_cmd_map_shared_mem *cmd;
        phys_addr_t paddr;
        int ret, i;
        u32 status;

        if (!count || !start || !buf_id)
                return -EINVAL;

        cmd = kzalloc_obj(*cmd);
        if (!cmd)
                return -ENOMEM;

        /* Size must be page aligned */
        for (i = 0; i < count ; i++) {
                if (!start[i].kaddr || (start[i].size & (PAGE_SIZE - 1))) {
                        ret = -EINVAL;
                        goto free_cmd;
                }

                if ((u64)start[i].kaddr & (PAGE_SIZE - 1)) {
                        pr_err("map shared memory: page unaligned. addr 0x%llx",
                               (u64)start[i].kaddr);
                        ret = -EINVAL;
                        goto free_cmd;
                }
        }

        cmd->sg_list.count = count;

        /* Create buffer list */
        for (i = 0; i < count ; i++) {
                paddr = __psp_pa(start[i].kaddr);
                cmd->sg_list.buf[i].hi_addr = upper_32_bits(paddr);
                cmd->sg_list.buf[i].low_addr = lower_32_bits(paddr);
                cmd->sg_list.buf[i].size = start[i].size;
                cmd->sg_list.size += cmd->sg_list.buf[i].size;

                pr_debug("buf[%d]:hi addr = 0x%x\n", i,
                         cmd->sg_list.buf[i].hi_addr);
                pr_debug("buf[%d]:low addr = 0x%x\n", i,
                         cmd->sg_list.buf[i].low_addr);
                pr_debug("buf[%d]:size = 0x%x\n", i, cmd->sg_list.buf[i].size);
                pr_debug("list size = 0x%x\n", cmd->sg_list.size);
        }

        *buf_id = 0;

        ret = psp_tee_process_cmd(TEE_CMD_ID_MAP_SHARED_MEM, (void *)cmd,
                                  sizeof(*cmd), &status);
        if (!ret && !status) {
                *buf_id = cmd->buf_id;
                pr_debug("mapped buffer ID = 0x%x\n", *buf_id);
        } else {
                pr_err("map shared memory: status = 0x%x\n", status);
                ret = -ENOMEM;
        }

free_cmd:
        kfree(cmd);

        return ret;
}

int handle_open_session(struct tee_ioctl_open_session_arg *arg, u32 *info,
                        struct tee_param *p)
{
        struct tee_cmd_open_session cmd = {0};
        int ret;

        if (!arg || !info || (!p && arg->num_params))
                return -EINVAL;

        arg->ret_origin = TEEC_ORIGIN_COMMS;

        if (arg->session == 0) {
                arg->ret = TEEC_ERROR_GENERIC;
                return -EINVAL;
        }

        ret = tee_params_to_amd_params(p, arg->num_params, &cmd.op);
        if (ret) {
                pr_err("invalid Params. Abort open session\n");
                arg->ret = TEEC_ERROR_BAD_PARAMETERS;
                return ret;
        }

        cmd.ta_handle = get_ta_handle(arg->session);
        *info = 0;

        ret = psp_tee_process_cmd(TEE_CMD_ID_OPEN_SESSION, (void *)&cmd,
                                  sizeof(cmd), &arg->ret);
        if (ret) {
                arg->ret = TEEC_ERROR_COMMUNICATION;
        } else {
                ret = amd_params_to_tee_params(p, arg->num_params, &cmd.op);
                if (unlikely(ret)) {
                        pr_err("open session: failed to copy output\n");
                        arg->ret = TEEC_ERROR_GENERIC;
                        return ret;
                }
                arg->ret_origin = cmd.return_origin;
                *info = cmd.session_info;
                pr_debug("open session: session info = 0x%x\n", *info);
        }

        pr_debug("open session: ret = 0x%x RO = 0x%x\n", arg->ret,
                 arg->ret_origin);

        return ret;
}

int handle_load_ta(void *data, u32 size, struct tee_ioctl_open_session_arg *arg)
{
        struct tee_cmd_unload_ta unload_cmd = {};
        struct tee_cmd_load_ta load_cmd = {};
        phys_addr_t blob;
        int ret;

        if (size == 0 || !data || !arg)
                return -EINVAL;

        blob = __psp_pa(data);
        if (blob & (PAGE_SIZE - 1)) {
                pr_err("load TA: page unaligned. blob 0x%llx", blob);
                return -EINVAL;
        }

        load_cmd.hi_addr = upper_32_bits(blob);
        load_cmd.low_addr = lower_32_bits(blob);
        load_cmd.size = size;

        mutex_lock(&ta_refcount_mutex);

        ret = psp_tee_process_cmd(TEE_CMD_ID_LOAD_TA, (void *)&load_cmd,
                                  sizeof(load_cmd), &arg->ret);
        if (ret) {
                arg->ret_origin = TEEC_ORIGIN_COMMS;
                arg->ret = TEEC_ERROR_COMMUNICATION;
        } else {
                arg->ret_origin = load_cmd.return_origin;

                if (arg->ret == TEEC_SUCCESS) {
                        ret = get_ta_refcount(load_cmd.ta_handle);
                        if (!ret) {
                                arg->ret_origin = TEEC_ORIGIN_COMMS;
                                arg->ret = TEEC_ERROR_OUT_OF_MEMORY;

                                /* Unload the TA on error */
                                unload_cmd.ta_handle = load_cmd.ta_handle;
                                psp_tee_process_cmd(TEE_CMD_ID_UNLOAD_TA,
                                                    (void *)&unload_cmd,
                                                    sizeof(unload_cmd), &ret);
                        } else {
                                set_session_id(load_cmd.ta_handle, 0, &arg->session);
                        }
                }
        }
        mutex_unlock(&ta_refcount_mutex);

        pr_debug("load TA: TA handle = 0x%x, RO = 0x%x, ret = 0x%x\n",
                 load_cmd.ta_handle, arg->ret_origin, arg->ret);

        return 0;
}