// SPDX-License-Identifier: GPL-2.0
/*
 * Copyright 2019 Broadcom.
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/sizes.h>
#include <linux/slab.h>
#include <linux/tee_drv.h>
#include <linux/uuid.h>

#include <linux/firmware/broadcom/tee_bnxt_fw.h>

#define MAX_SHM_MEM_SZ  SZ_4M

#define MAX_TEE_PARAM_ARRY_MEMB         4

enum ta_cmd {
        /*
         * TA_CMD_BNXT_FASTBOOT - boot bnxt device by copying f/w into sram
         *
         *      param[0] unused
         *      param[1] unused
         *      param[2] unused
         *      param[3] unused
         *
         * Result:
         *      TEE_SUCCESS - Invoke command success
         *      TEE_ERROR_ITEM_NOT_FOUND - Corrupt f/w image found on memory
         */
        TA_CMD_BNXT_FASTBOOT = 0,

        /*
         * TA_CMD_BNXT_COPY_COREDUMP - copy the core dump into shm
         *
         *      param[0] (inout memref) - Coredump buffer memory reference
         *      param[1] (in value) - value.a: offset, data to be copied from
         *                            value.b: size of data to be copied
         *      param[2] unused
         *      param[3] unused
         *
         * Result:
         *      TEE_SUCCESS - Invoke command success
         *      TEE_ERROR_BAD_PARAMETERS - Incorrect input param
         *      TEE_ERROR_ITEM_NOT_FOUND - Corrupt core dump
         */
        TA_CMD_BNXT_COPY_COREDUMP = 3,
};

/**
 * struct tee_bnxt_fw_private - OP-TEE bnxt private data
 * @dev:                OP-TEE based bnxt device.
 * @ctx:                OP-TEE context handler.
 * @session_id:         TA session identifier.
 */
struct tee_bnxt_fw_private {
        struct device *dev;
        struct tee_context *ctx;
        u32 session_id;
        struct tee_shm *fw_shm_pool;
};

static struct tee_bnxt_fw_private pvt_data;

static void prepare_args(int cmd,
                         struct tee_ioctl_invoke_arg *arg,
                         struct tee_param *param)
{
        memset(arg, 0, sizeof(*arg));
        memset(param, 0, MAX_TEE_PARAM_ARRY_MEMB * sizeof(*param));

        arg->func = cmd;
        arg->session = pvt_data.session_id;
        arg->num_params = MAX_TEE_PARAM_ARRY_MEMB;

        /* Fill invoke cmd params */
        switch (cmd) {
        case TA_CMD_BNXT_COPY_COREDUMP:
                param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT;
                param[0].u.memref.shm = pvt_data.fw_shm_pool;
                param[0].u.memref.size = MAX_SHM_MEM_SZ;
                param[0].u.memref.shm_offs = 0;
                param[1].attr = TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT;
                break;
        case TA_CMD_BNXT_FASTBOOT:
        default:
                /* Nothing to do */
                break;
        }
}

/**
 * tee_bnxt_fw_load() - Load the bnxt firmware
 *                  Uses an OP-TEE call to start a secure
 *                  boot process.
 * Returns 0 on success, negative errno otherwise.
 */
int tee_bnxt_fw_load(void)
{
        int ret = 0;
        struct tee_ioctl_invoke_arg arg;
        struct tee_param param[MAX_TEE_PARAM_ARRY_MEMB];

        if (!pvt_data.ctx)
                return -ENODEV;

        prepare_args(TA_CMD_BNXT_FASTBOOT, &arg, param);

        ret = tee_client_invoke_func(pvt_data.ctx, &arg, param);
        if (ret < 0 || arg.ret != 0) {
                dev_err(pvt_data.dev,
                        "TA_CMD_BNXT_FASTBOOT invoke failed TEE err: %x, ret:%x\n",
                        arg.ret, ret);
                return -EINVAL;
        }

        return 0;
}
EXPORT_SYMBOL(tee_bnxt_fw_load);

/**
 * tee_bnxt_copy_coredump() - Copy coredump from the allocated memory
 *                          Uses an OP-TEE call to copy coredump
 * @buf:        destination buffer where core dump is copied into
 * @offset:     offset from the base address of core dump area
 * @size:       size of the dump
 *
 * Returns 0 on success, negative errno otherwise.
 */
int tee_bnxt_copy_coredump(void *buf, u32 offset, u32 size)
{
        struct tee_ioctl_invoke_arg arg;
        struct tee_param param[MAX_TEE_PARAM_ARRY_MEMB];
        void *core_data;
        u32 rbytes = size;
        u32 nbytes = 0;
        int ret = 0;

        if (!pvt_data.ctx)
                return -ENODEV;

        prepare_args(TA_CMD_BNXT_COPY_COREDUMP, &arg, param);

        while (rbytes)  {
                nbytes = rbytes;

                nbytes = min_t(u32, rbytes, param[0].u.memref.size);

                /* Fill additional invoke cmd params */
                param[1].u.value.a = offset;
                param[1].u.value.b = nbytes;

                ret = tee_client_invoke_func(pvt_data.ctx, &arg, param);
                if (ret < 0 || arg.ret != 0) {
                        dev_err(pvt_data.dev,
                                "TA_CMD_BNXT_COPY_COREDUMP invoke failed TEE err: %x, ret:%x\n",
                                arg.ret, ret);
                        return -EINVAL;
                }

                core_data = tee_shm_get_va(pvt_data.fw_shm_pool, 0);
                if (IS_ERR(core_data)) {
                        dev_err(pvt_data.dev, "tee_shm_get_va failed\n");
                        return PTR_ERR(core_data);
                }

                memcpy(buf, core_data, nbytes);

                rbytes -= nbytes;
                buf += nbytes;
                offset += nbytes;
        }

        return 0;
}
EXPORT_SYMBOL(tee_bnxt_copy_coredump);

static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
{
        return (ver->impl_id == TEE_IMPL_ID_OPTEE);
}

static int tee_bnxt_fw_probe(struct device *dev)
{
        struct tee_client_device *bnxt_device = to_tee_client_device(dev);
        int ret, err = -ENODEV;
        struct tee_ioctl_open_session_arg sess_arg;
        struct tee_shm *fw_shm_pool;

        memset(&sess_arg, 0, sizeof(sess_arg));

        /* Open context with TEE driver */
        pvt_data.ctx = tee_client_open_context(NULL, optee_ctx_match, NULL,
                                               NULL);
        if (IS_ERR(pvt_data.ctx))
                return -ENODEV;

        /* Open session with Bnxt load Trusted App */
        memcpy(sess_arg.uuid, bnxt_device->id.uuid.b, TEE_IOCTL_UUID_LEN);
        sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
        sess_arg.num_params = 0;

        ret = tee_client_open_session(pvt_data.ctx, &sess_arg, NULL);
        if (ret < 0 || sess_arg.ret != 0) {
                dev_err(dev, "tee_client_open_session failed, err: %x\n",
                        sess_arg.ret);
                err = -EINVAL;
                goto out_ctx;
        }
        pvt_data.session_id = sess_arg.session;

        pvt_data.dev = dev;

        fw_shm_pool = tee_shm_alloc_kernel_buf(pvt_data.ctx, MAX_SHM_MEM_SZ);
        if (IS_ERR(fw_shm_pool)) {
                dev_err(pvt_data.dev, "tee_shm_alloc_kernel_buf failed\n");
                err = PTR_ERR(fw_shm_pool);
                goto out_sess;
        }

        pvt_data.fw_shm_pool = fw_shm_pool;

        return 0;

out_sess:
        tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
out_ctx:
        tee_client_close_context(pvt_data.ctx);

        return err;
}

static int tee_bnxt_fw_remove(struct device *dev)
{
        tee_shm_free(pvt_data.fw_shm_pool);
        tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
        tee_client_close_context(pvt_data.ctx);
        pvt_data.ctx = NULL;

        return 0;
}

static void tee_bnxt_fw_shutdown(struct device *dev)
{
        tee_shm_free(pvt_data.fw_shm_pool);
        tee_client_close_session(pvt_data.ctx, pvt_data.session_id);
        tee_client_close_context(pvt_data.ctx);
        pvt_data.ctx = NULL;
}

static const struct tee_client_device_id tee_bnxt_fw_id_table[] = {
        {UUID_INIT(0x6272636D, 0x2019, 0x0716,
                    0x42, 0x43, 0x4D, 0x5F, 0x53, 0x43, 0x48, 0x49)},
        {}
};

MODULE_DEVICE_TABLE(tee, tee_bnxt_fw_id_table);

static struct tee_client_driver tee_bnxt_fw_driver = {
        .id_table       = tee_bnxt_fw_id_table,
        .driver         = {
                .name           = KBUILD_MODNAME,
                .bus            = &tee_bus_type,
                .probe          = tee_bnxt_fw_probe,
                .remove         = tee_bnxt_fw_remove,
                .shutdown       = tee_bnxt_fw_shutdown,
        },
};

static int __init tee_bnxt_fw_mod_init(void)
{
        return driver_register(&tee_bnxt_fw_driver.driver);
}

static void __exit tee_bnxt_fw_mod_exit(void)
{
        driver_unregister(&tee_bnxt_fw_driver.driver);
}

module_init(tee_bnxt_fw_mod_init);
module_exit(tee_bnxt_fw_mod_exit);

MODULE_AUTHOR("Vikas Gupta <vikas.gupta@broadcom.com>");
MODULE_DESCRIPTION("Broadcom bnxt firmware manager");
MODULE_LICENSE("GPL v2");