Merge tag 'trace-printf-v6.13' of git://git.kernel.org/pub/scm/linux/kernel/git/trace...

[drm/drm-misc.git] / drivers / tee / optee / ffa_abi.c

// SPDX-License-Identifier: GPL-2.0-only
/*
 * Copyright (c) 2021, 2023 Linaro Limited
 */

#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt

#include <linux/arm_ffa.h>
#include <linux/errno.h>
#include <linux/rpmb.h>
#include <linux/scatterlist.h>
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/tee_core.h>
#include <linux/types.h>
#include "optee_private.h"
#include "optee_ffa.h"
#include "optee_rpc_cmd.h"

/*
 * This file implement the FF-A ABI used when communicating with secure world
 * OP-TEE OS via FF-A.
 * This file is divided into the following sections:
 * 1. Maintain a hash table for lookup of a global FF-A memory handle
 * 2. Convert between struct tee_param and struct optee_msg_param
 * 3. Low level support functions to register shared memory in secure world
 * 4. Dynamic shared memory pool based on alloc_pages()
 * 5. Do a normal scheduled call into secure world
 * 6. Driver initialization.
 */

/*
 * 1. Maintain a hash table for lookup of a global FF-A memory handle
 *
 * FF-A assigns a global memory handle for each piece shared memory.
 * This handle is then used when communicating with secure world.
 *
 * Main functions are optee_shm_add_ffa_handle() and optee_shm_rem_ffa_handle()
 */
struct shm_rhash {
        struct tee_shm *shm;
        u64 global_id;
        struct rhash_head linkage;
};

static void rh_free_fn(void *ptr, void *arg)
{
        kfree(ptr);
}

static const struct rhashtable_params shm_rhash_params = {
        .head_offset = offsetof(struct shm_rhash, linkage),
        .key_len     = sizeof(u64),
        .key_offset  = offsetof(struct shm_rhash, global_id),
        .automatic_shrinking = true,
};

static struct tee_shm *optee_shm_from_ffa_handle(struct optee *optee,
                                                 u64 global_id)
{
        struct tee_shm *shm = NULL;
        struct shm_rhash *r;

        mutex_lock(&optee->ffa.mutex);
        r = rhashtable_lookup_fast(&optee->ffa.global_ids, &global_id,
                                   shm_rhash_params);
        if (r)
                shm = r->shm;
        mutex_unlock(&optee->ffa.mutex);

        return shm;
}

static int optee_shm_add_ffa_handle(struct optee *optee, struct tee_shm *shm,
                                    u64 global_id)
{
        struct shm_rhash *r;
        int rc;

        r = kmalloc(sizeof(*r), GFP_KERNEL);
        if (!r)
                return -ENOMEM;
        r->shm = shm;
        r->global_id = global_id;

        mutex_lock(&optee->ffa.mutex);
        rc = rhashtable_lookup_insert_fast(&optee->ffa.global_ids, &r->linkage,
                                           shm_rhash_params);
        mutex_unlock(&optee->ffa.mutex);

        if (rc)
                kfree(r);

        return rc;
}

static int optee_shm_rem_ffa_handle(struct optee *optee, u64 global_id)
{
        struct shm_rhash *r;
        int rc = -ENOENT;

        mutex_lock(&optee->ffa.mutex);
        r = rhashtable_lookup_fast(&optee->ffa.global_ids, &global_id,
                                   shm_rhash_params);
        if (r)
                rc = rhashtable_remove_fast(&optee->ffa.global_ids,
                                            &r->linkage, shm_rhash_params);
        mutex_unlock(&optee->ffa.mutex);

        if (!rc)
                kfree(r);

        return rc;
}

/*
 * 2. Convert between struct tee_param and struct optee_msg_param
 *
 * optee_ffa_from_msg_param() and optee_ffa_to_msg_param() are the main
 * functions.
 */

static void from_msg_param_ffa_mem(struct optee *optee, struct tee_param *p,
                                   u32 attr, const struct optee_msg_param *mp)
{
        struct tee_shm *shm = NULL;
        u64 offs_high = 0;
        u64 offs_low = 0;

        p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT +
                  attr - OPTEE_MSG_ATTR_TYPE_FMEM_INPUT;
        p->u.memref.size = mp->u.fmem.size;

        if (mp->u.fmem.global_id != OPTEE_MSG_FMEM_INVALID_GLOBAL_ID)
                shm = optee_shm_from_ffa_handle(optee, mp->u.fmem.global_id);
        p->u.memref.shm = shm;

        if (shm) {
                offs_low = mp->u.fmem.offs_low;
                offs_high = mp->u.fmem.offs_high;
        }
        p->u.memref.shm_offs = offs_low | offs_high << 32;
}

/**
 * optee_ffa_from_msg_param() - convert from OPTEE_MSG parameters to
 *                              struct tee_param
 * @optee:      main service struct
 * @params:     subsystem internal parameter representation
 * @num_params: number of elements in the parameter arrays
 * @msg_params: OPTEE_MSG parameters
 *
 * Returns 0 on success or <0 on failure
 */
static int optee_ffa_from_msg_param(struct optee *optee,
                                    struct tee_param *params, size_t num_params,
                                    const struct optee_msg_param *msg_params)
{
        size_t n;

        for (n = 0; n < num_params; n++) {
                struct tee_param *p = params + n;
                const struct optee_msg_param *mp = msg_params + n;
                u32 attr = mp->attr & OPTEE_MSG_ATTR_TYPE_MASK;

                switch (attr) {
                case OPTEE_MSG_ATTR_TYPE_NONE:
                        p->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
                        memset(&p->u, 0, sizeof(p->u));
                        break;
                case OPTEE_MSG_ATTR_TYPE_VALUE_INPUT:
                case OPTEE_MSG_ATTR_TYPE_VALUE_OUTPUT:
                case OPTEE_MSG_ATTR_TYPE_VALUE_INOUT:
                        optee_from_msg_param_value(p, attr, mp);
                        break;
                case OPTEE_MSG_ATTR_TYPE_FMEM_INPUT:
                case OPTEE_MSG_ATTR_TYPE_FMEM_OUTPUT:
                case OPTEE_MSG_ATTR_TYPE_FMEM_INOUT:
                        from_msg_param_ffa_mem(optee, p, attr, mp);
                        break;
                default:
                        return -EINVAL;
                }
        }

        return 0;
}

static int to_msg_param_ffa_mem(struct optee_msg_param *mp,
                                const struct tee_param *p)
{
        struct tee_shm *shm = p->u.memref.shm;

        mp->attr = OPTEE_MSG_ATTR_TYPE_FMEM_INPUT + p->attr -
                   TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT;

        if (shm) {
                u64 shm_offs = p->u.memref.shm_offs;

                mp->u.fmem.internal_offs = shm->offset;

                mp->u.fmem.offs_low = shm_offs;
                mp->u.fmem.offs_high = shm_offs >> 32;
                /* Check that the entire offset could be stored. */
                if (mp->u.fmem.offs_high != shm_offs >> 32)
                        return -EINVAL;

                mp->u.fmem.global_id = shm->sec_world_id;
        } else {
                memset(&mp->u, 0, sizeof(mp->u));
                mp->u.fmem.global_id = OPTEE_MSG_FMEM_INVALID_GLOBAL_ID;
        }
        mp->u.fmem.size = p->u.memref.size;

        return 0;
}

/**
 * optee_ffa_to_msg_param() - convert from struct tee_params to OPTEE_MSG
 *                            parameters
 * @optee:      main service struct
 * @msg_params: OPTEE_MSG parameters
 * @num_params: number of elements in the parameter arrays
 * @params:     subsystem itnernal parameter representation
 * Returns 0 on success or <0 on failure
 */
static int optee_ffa_to_msg_param(struct optee *optee,
                                  struct optee_msg_param *msg_params,
                                  size_t num_params,
                                  const struct tee_param *params)
{
        size_t n;

        for (n = 0; n < num_params; n++) {
                const struct tee_param *p = params + n;
                struct optee_msg_param *mp = msg_params + n;

                switch (p->attr) {
                case TEE_IOCTL_PARAM_ATTR_TYPE_NONE:
                        mp->attr = TEE_IOCTL_PARAM_ATTR_TYPE_NONE;
                        memset(&mp->u, 0, sizeof(mp->u));
                        break;
                case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INPUT:
                case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_OUTPUT:
                case TEE_IOCTL_PARAM_ATTR_TYPE_VALUE_INOUT:
                        optee_to_msg_param_value(mp, p);
                        break;
                case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INPUT:
                case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT:
                case TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_INOUT:
                        if (to_msg_param_ffa_mem(mp, p))
                                return -EINVAL;
                        break;
                default:
                        return -EINVAL;
                }
        }

        return 0;
}

/*
 * 3. Low level support functions to register shared memory in secure world
 *
 * Functions to register and unregister shared memory both for normal
 * clients and for tee-supplicant.
 */

static int optee_ffa_shm_register(struct tee_context *ctx, struct tee_shm *shm,
                                  struct page **pages, size_t num_pages,
                                  unsigned long start)
{
        struct optee *optee = tee_get_drvdata(ctx->teedev);
        struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
        const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
        struct ffa_mem_region_attributes mem_attr = {
                .receiver = ffa_dev->vm_id,
                .attrs = FFA_MEM_RW,
        };
        struct ffa_mem_ops_args args = {
                .use_txbuf = true,
                .attrs = &mem_attr,
                .nattrs = 1,
        };
        struct sg_table sgt;
        int rc;

        rc = optee_check_mem_type(start, num_pages);
        if (rc)
                return rc;

        rc = sg_alloc_table_from_pages(&sgt, pages, num_pages, 0,
                                       num_pages * PAGE_SIZE, GFP_KERNEL);
        if (rc)
                return rc;
        args.sg = sgt.sgl;
        rc = mem_ops->memory_share(&args);
        sg_free_table(&sgt);
        if (rc)
                return rc;

        rc = optee_shm_add_ffa_handle(optee, shm, args.g_handle);
        if (rc) {
                mem_ops->memory_reclaim(args.g_handle, 0);
                return rc;
        }

        shm->sec_world_id = args.g_handle;

        return 0;
}

static int optee_ffa_shm_unregister(struct tee_context *ctx,
                                    struct tee_shm *shm)
{
        struct optee *optee = tee_get_drvdata(ctx->teedev);
        struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
        const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
        const struct ffa_mem_ops *mem_ops = ffa_dev->ops->mem_ops;
        u64 global_handle = shm->sec_world_id;
        struct ffa_send_direct_data data = {
                .data0 = OPTEE_FFA_UNREGISTER_SHM,
                .data1 = (u32)global_handle,
                .data2 = (u32)(global_handle >> 32)
        };
        int rc;

        optee_shm_rem_ffa_handle(optee, global_handle);
        shm->sec_world_id = 0;

        rc = msg_ops->sync_send_receive(ffa_dev, &data);
        if (rc)
                pr_err("Unregister SHM id 0x%llx rc %d\n", global_handle, rc);

        rc = mem_ops->memory_reclaim(global_handle, 0);
        if (rc)
                pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);

        return rc;
}

static int optee_ffa_shm_unregister_supp(struct tee_context *ctx,
                                         struct tee_shm *shm)
{
        struct optee *optee = tee_get_drvdata(ctx->teedev);
        const struct ffa_mem_ops *mem_ops;
        u64 global_handle = shm->sec_world_id;
        int rc;

        /*
         * We're skipping the OPTEE_FFA_YIELDING_CALL_UNREGISTER_SHM call
         * since this is OP-TEE freeing via RPC so it has already retired
         * this ID.
         */

        optee_shm_rem_ffa_handle(optee, global_handle);
        mem_ops = optee->ffa.ffa_dev->ops->mem_ops;
        rc = mem_ops->memory_reclaim(global_handle, 0);
        if (rc)
                pr_err("mem_reclaim: 0x%llx %d", global_handle, rc);

        shm->sec_world_id = 0;

        return rc;
}

/*
 * 4. Dynamic shared memory pool based on alloc_pages()
 *
 * Implements an OP-TEE specific shared memory pool.
 * The main function is optee_ffa_shm_pool_alloc_pages().
 */

static int pool_ffa_op_alloc(struct tee_shm_pool *pool,
                             struct tee_shm *shm, size_t size, size_t align)
{
        return tee_dyn_shm_alloc_helper(shm, size, align,
                                        optee_ffa_shm_register);
}

static void pool_ffa_op_free(struct tee_shm_pool *pool,
                             struct tee_shm *shm)
{
        tee_dyn_shm_free_helper(shm, optee_ffa_shm_unregister);
}

static void pool_ffa_op_destroy_pool(struct tee_shm_pool *pool)
{
        kfree(pool);
}

static const struct tee_shm_pool_ops pool_ffa_ops = {
        .alloc = pool_ffa_op_alloc,
        .free = pool_ffa_op_free,
        .destroy_pool = pool_ffa_op_destroy_pool,
};

/**
 * optee_ffa_shm_pool_alloc_pages() - create page-based allocator pool
 *
 * This pool is used with OP-TEE over FF-A. In this case command buffers
 * and such are allocated from kernel's own memory.
 */
static struct tee_shm_pool *optee_ffa_shm_pool_alloc_pages(void)
{
        struct tee_shm_pool *pool = kzalloc(sizeof(*pool), GFP_KERNEL);

        if (!pool)
                return ERR_PTR(-ENOMEM);

        pool->ops = &pool_ffa_ops;

        return pool;
}

/*
 * 5. Do a normal scheduled call into secure world
 *
 * The function optee_ffa_do_call_with_arg() performs a normal scheduled
 * call into secure world. During this call may normal world request help
 * from normal world using RPCs, Remote Procedure Calls. This includes
 * delivery of non-secure interrupts to for instance allow rescheduling of
 * the current task.
 */

static void handle_ffa_rpc_func_cmd_shm_alloc(struct tee_context *ctx,
                                              struct optee *optee,
                                              struct optee_msg_arg *arg)
{
        struct tee_shm *shm;

        if (arg->num_params != 1 ||
            arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT) {
                arg->ret = TEEC_ERROR_BAD_PARAMETERS;
                return;
        }

        switch (arg->params[0].u.value.a) {
        case OPTEE_RPC_SHM_TYPE_APPL:
                shm = optee_rpc_cmd_alloc_suppl(ctx, arg->params[0].u.value.b);
                break;
        case OPTEE_RPC_SHM_TYPE_KERNEL:
                shm = tee_shm_alloc_priv_buf(optee->ctx,
                                             arg->params[0].u.value.b);
                break;
        default:
                arg->ret = TEEC_ERROR_BAD_PARAMETERS;
                return;
        }

        if (IS_ERR(shm)) {
                arg->ret = TEEC_ERROR_OUT_OF_MEMORY;
                return;
        }

        arg->params[0] = (struct optee_msg_param){
                .attr = OPTEE_MSG_ATTR_TYPE_FMEM_OUTPUT,
                .u.fmem.size = tee_shm_get_size(shm),
                .u.fmem.global_id = shm->sec_world_id,
                .u.fmem.internal_offs = shm->offset,
        };

        arg->ret = TEEC_SUCCESS;
}

static void handle_ffa_rpc_func_cmd_shm_free(struct tee_context *ctx,
                                             struct optee *optee,
                                             struct optee_msg_arg *arg)
{
        struct tee_shm *shm;

        if (arg->num_params != 1 ||
            arg->params[0].attr != OPTEE_MSG_ATTR_TYPE_VALUE_INPUT)
                goto err_bad_param;

        shm = optee_shm_from_ffa_handle(optee, arg->params[0].u.value.b);
        if (!shm)
                goto err_bad_param;
        switch (arg->params[0].u.value.a) {
        case OPTEE_RPC_SHM_TYPE_APPL:
                optee_rpc_cmd_free_suppl(ctx, shm);
                break;
        case OPTEE_RPC_SHM_TYPE_KERNEL:
                tee_shm_free(shm);
                break;
        default:
                goto err_bad_param;
        }
        arg->ret = TEEC_SUCCESS;
        return;

err_bad_param:
        arg->ret = TEEC_ERROR_BAD_PARAMETERS;
}

static void handle_ffa_rpc_func_cmd(struct tee_context *ctx,
                                    struct optee *optee,
                                    struct optee_msg_arg *arg)
{
        arg->ret_origin = TEEC_ORIGIN_COMMS;
        switch (arg->cmd) {
        case OPTEE_RPC_CMD_SHM_ALLOC:
                handle_ffa_rpc_func_cmd_shm_alloc(ctx, optee, arg);
                break;
        case OPTEE_RPC_CMD_SHM_FREE:
                handle_ffa_rpc_func_cmd_shm_free(ctx, optee, arg);
                break;
        default:
                optee_rpc_cmd(ctx, optee, arg);
        }
}

static void optee_handle_ffa_rpc(struct tee_context *ctx, struct optee *optee,
                                 u32 cmd, struct optee_msg_arg *arg)
{
        switch (cmd) {
        case OPTEE_FFA_YIELDING_CALL_RETURN_RPC_CMD:
                handle_ffa_rpc_func_cmd(ctx, optee, arg);
                break;
        case OPTEE_FFA_YIELDING_CALL_RETURN_INTERRUPT:
                /* Interrupt delivered by now */
                break;
        default:
                pr_warn("Unknown RPC func 0x%x\n", cmd);
                break;
        }
}

static int optee_ffa_yielding_call(struct tee_context *ctx,
                                   struct ffa_send_direct_data *data,
                                   struct optee_msg_arg *rpc_arg,
                                   bool system_thread)
{
        struct optee *optee = tee_get_drvdata(ctx->teedev);
        struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
        const struct ffa_msg_ops *msg_ops = ffa_dev->ops->msg_ops;
        struct optee_call_waiter w;
        u32 cmd = data->data0;
        u32 w4 = data->data1;
        u32 w5 = data->data2;
        u32 w6 = data->data3;
        int rc;

        /* Initialize waiter */
        optee_cq_wait_init(&optee->call_queue, &w, system_thread);
        while (true) {
                rc = msg_ops->sync_send_receive(ffa_dev, data);
                if (rc)
                        goto done;

                switch ((int)data->data0) {
                case TEEC_SUCCESS:
                        break;
                case TEEC_ERROR_BUSY:
                        if (cmd == OPTEE_FFA_YIELDING_CALL_RESUME) {
                                rc = -EIO;
                                goto done;
                        }

                        /*
                         * Out of threads in secure world, wait for a thread
                         * become available.
                         */
                        optee_cq_wait_for_completion(&optee->call_queue, &w);
                        data->data0 = cmd;
                        data->data1 = w4;
                        data->data2 = w5;
                        data->data3 = w6;
                        continue;
                default:
                        rc = -EIO;
                        goto done;
                }

                if (data->data1 == OPTEE_FFA_YIELDING_CALL_RETURN_DONE)
                        goto done;

                /*
                 * OP-TEE has returned with a RPC request.
                 *
                 * Note that data->data4 (passed in register w7) is already
                 * filled in by ffa_mem_ops->sync_send_receive() returning
                 * above.
                 */
                cond_resched();
                optee_handle_ffa_rpc(ctx, optee, data->data1, rpc_arg);
                cmd = OPTEE_FFA_YIELDING_CALL_RESUME;
                data->data0 = cmd;
                data->data1 = 0;
                data->data2 = 0;
                data->data3 = 0;
        }
done:
        /*
         * We're done with our thread in secure world, if there's any
         * thread waiters wake up one.
         */
        optee_cq_wait_final(&optee->call_queue, &w);

        return rc;
}

/**
 * optee_ffa_do_call_with_arg() - Do a FF-A call to enter OP-TEE in secure world
 * @ctx:        calling context
 * @shm:        shared memory holding the message to pass to secure world
 * @offs:       offset of the message in @shm
 * @system_thread: true if caller requests TEE system thread support
 *
 * Does a FF-A call to OP-TEE in secure world and handles eventual resulting
 * Remote Procedure Calls (RPC) from OP-TEE.
 *
 * Returns return code from FF-A, 0 is OK
 */

static int optee_ffa_do_call_with_arg(struct tee_context *ctx,
                                      struct tee_shm *shm, u_int offs,
                                      bool system_thread)
{
        struct ffa_send_direct_data data = {
                .data0 = OPTEE_FFA_YIELDING_CALL_WITH_ARG,
                .data1 = (u32)shm->sec_world_id,
                .data2 = (u32)(shm->sec_world_id >> 32),
                .data3 = offs,
        };
        struct optee_msg_arg *arg;
        unsigned int rpc_arg_offs;
        struct optee_msg_arg *rpc_arg;

        /*
         * The shared memory object has to start on a page when passed as
         * an argument struct. This is also what the shm pool allocator
         * returns, but check this before calling secure world to catch
         * eventual errors early in case something changes.
         */
        if (shm->offset)
                return -EINVAL;

        arg = tee_shm_get_va(shm, offs);
        if (IS_ERR(arg))
                return PTR_ERR(arg);

        rpc_arg_offs = OPTEE_MSG_GET_ARG_SIZE(arg->num_params);
        rpc_arg = tee_shm_get_va(shm, offs + rpc_arg_offs);
        if (IS_ERR(rpc_arg))
                return PTR_ERR(rpc_arg);

        return optee_ffa_yielding_call(ctx, &data, rpc_arg, system_thread);
}

/*
 * 6. Driver initialization
 *
 * During driver inititialization is the OP-TEE Secure Partition is probed
 * to find out which features it supports so the driver can be initialized
 * with a matching configuration.
 */

static bool optee_ffa_api_is_compatbile(struct ffa_device *ffa_dev,
                                        const struct ffa_ops *ops)
{
        const struct ffa_msg_ops *msg_ops = ops->msg_ops;
        struct ffa_send_direct_data data = {
                .data0 = OPTEE_FFA_GET_API_VERSION,
        };
        int rc;

        msg_ops->mode_32bit_set(ffa_dev);

        rc = msg_ops->sync_send_receive(ffa_dev, &data);
        if (rc) {
                pr_err("Unexpected error %d\n", rc);
                return false;
        }
        if (data.data0 != OPTEE_FFA_VERSION_MAJOR ||
            data.data1 < OPTEE_FFA_VERSION_MINOR) {
                pr_err("Incompatible OP-TEE API version %lu.%lu",
                       data.data0, data.data1);
                return false;
        }

        data = (struct ffa_send_direct_data){
                .data0 = OPTEE_FFA_GET_OS_VERSION,
        };
        rc = msg_ops->sync_send_receive(ffa_dev, &data);
        if (rc) {
                pr_err("Unexpected error %d\n", rc);
                return false;
        }
        if (data.data2)
                pr_info("revision %lu.%lu (%08lx)",
                        data.data0, data.data1, data.data2);
        else
                pr_info("revision %lu.%lu", data.data0, data.data1);

        return true;
}

static bool optee_ffa_exchange_caps(struct ffa_device *ffa_dev,
                                    const struct ffa_ops *ops,
                                    u32 *sec_caps,
                                    unsigned int *rpc_param_count,
                                    unsigned int *max_notif_value)
{
        struct ffa_send_direct_data data = {
                .data0 = OPTEE_FFA_EXCHANGE_CAPABILITIES,
        };
        int rc;

        rc = ops->msg_ops->sync_send_receive(ffa_dev, &data);
        if (rc) {
                pr_err("Unexpected error %d", rc);
                return false;
        }
        if (data.data0) {
                pr_err("Unexpected exchange error %lu", data.data0);
                return false;
        }

        *rpc_param_count = (u8)data.data1;
        *sec_caps = data.data2;
        if (data.data3)
                *max_notif_value = data.data3;
        else
                *max_notif_value = OPTEE_DEFAULT_MAX_NOTIF_VALUE;

        return true;
}

static void notif_callback(int notify_id, void *cb_data)
{
        struct optee *optee = cb_data;

        if (notify_id == optee->ffa.bottom_half_value)
                optee_do_bottom_half(optee->ctx);
        else
                optee_notif_send(optee, notify_id);
}

static int enable_async_notif(struct optee *optee)
{
        struct ffa_device *ffa_dev = optee->ffa.ffa_dev;
        struct ffa_send_direct_data data = {
                .data0 = OPTEE_FFA_ENABLE_ASYNC_NOTIF,
                .data1 = optee->ffa.bottom_half_value,
        };
        int rc;

        rc = ffa_dev->ops->msg_ops->sync_send_receive(ffa_dev, &data);
        if (rc)
                return rc;
        return data.data0;
}

static void optee_ffa_get_version(struct tee_device *teedev,
                                  struct tee_ioctl_version_data *vers)
{
        struct tee_ioctl_version_data v = {
                .impl_id = TEE_IMPL_ID_OPTEE,
                .impl_caps = TEE_OPTEE_CAP_TZ,
                .gen_caps = TEE_GEN_CAP_GP | TEE_GEN_CAP_REG_MEM |
                            TEE_GEN_CAP_MEMREF_NULL,
        };

        *vers = v;
}

static int optee_ffa_open(struct tee_context *ctx)
{
        return optee_open(ctx, true);
}

static const struct tee_driver_ops optee_ffa_clnt_ops = {
        .get_version = optee_ffa_get_version,
        .open = optee_ffa_open,
        .release = optee_release,
        .open_session = optee_open_session,
        .close_session = optee_close_session,
        .invoke_func = optee_invoke_func,
        .cancel_req = optee_cancel_req,
        .shm_register = optee_ffa_shm_register,
        .shm_unregister = optee_ffa_shm_unregister,
};

static const struct tee_desc optee_ffa_clnt_desc = {
        .name = DRIVER_NAME "-ffa-clnt",
        .ops = &optee_ffa_clnt_ops,
        .owner = THIS_MODULE,
};

static const struct tee_driver_ops optee_ffa_supp_ops = {
        .get_version = optee_ffa_get_version,
        .open = optee_ffa_open,
        .release = optee_release_supp,
        .supp_recv = optee_supp_recv,
        .supp_send = optee_supp_send,
        .shm_register = optee_ffa_shm_register, /* same as for clnt ops */
        .shm_unregister = optee_ffa_shm_unregister_supp,
};

static const struct tee_desc optee_ffa_supp_desc = {
        .name = DRIVER_NAME "-ffa-supp",
        .ops = &optee_ffa_supp_ops,
        .owner = THIS_MODULE,
        .flags = TEE_DESC_PRIVILEGED,
};

static const struct optee_ops optee_ffa_ops = {
        .do_call_with_arg = optee_ffa_do_call_with_arg,
        .to_msg_param = optee_ffa_to_msg_param,
        .from_msg_param = optee_ffa_from_msg_param,
};

static void optee_ffa_remove(struct ffa_device *ffa_dev)
{
        struct optee *optee = ffa_dev_get_drvdata(ffa_dev);
        u32 bottom_half_id = optee->ffa.bottom_half_value;

        if (bottom_half_id != U32_MAX)
                ffa_dev->ops->notifier_ops->notify_relinquish(ffa_dev,
                                                              bottom_half_id);
        optee_remove_common(optee);

        mutex_destroy(&optee->ffa.mutex);
        rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);

        kfree(optee);
}

static int optee_ffa_async_notif_init(struct ffa_device *ffa_dev,
                                      struct optee *optee)
{
        bool is_per_vcpu = false;
        u32 notif_id = 0;
        int rc;

        while (true) {
                rc = ffa_dev->ops->notifier_ops->notify_request(ffa_dev,
                                                                is_per_vcpu,
                                                                notif_callback,
                                                                optee,
                                                                notif_id);
                if (!rc)
                        break;
                /*
                 * -EACCES means that the notification ID was
                 * already bound, try the next one as long as we
                 * haven't reached the max. Any other error is a
                 * permanent error, so skip asynchronous
                 * notifications in that case.
                 */
                if (rc != -EACCES)
                        return rc;
                notif_id++;
                if (notif_id >= OPTEE_FFA_MAX_ASYNC_NOTIF_VALUE)
                        return rc;
        }
        optee->ffa.bottom_half_value = notif_id;

        rc = enable_async_notif(optee);
        if (rc < 0) {
                ffa_dev->ops->notifier_ops->notify_relinquish(ffa_dev,
                                                              notif_id);
                optee->ffa.bottom_half_value = U32_MAX;
        }

        return rc;
}

static int optee_ffa_probe(struct ffa_device *ffa_dev)
{
        const struct ffa_notifier_ops *notif_ops;
        const struct ffa_ops *ffa_ops;
        unsigned int max_notif_value;
        unsigned int rpc_param_count;
        struct tee_shm_pool *pool;
        struct tee_device *teedev;
        struct tee_context *ctx;
        u32 arg_cache_flags = 0;
        struct optee *optee;
        u32 sec_caps;
        int rc;

        ffa_ops = ffa_dev->ops;
        notif_ops = ffa_ops->notifier_ops;

        if (!optee_ffa_api_is_compatbile(ffa_dev, ffa_ops))
                return -EINVAL;

        if (!optee_ffa_exchange_caps(ffa_dev, ffa_ops, &sec_caps,
                                     &rpc_param_count, &max_notif_value))
                return -EINVAL;
        if (sec_caps & OPTEE_FFA_SEC_CAP_ARG_OFFSET)
                arg_cache_flags |= OPTEE_SHM_ARG_SHARED;

        optee = kzalloc(sizeof(*optee), GFP_KERNEL);
        if (!optee)
                return -ENOMEM;

        pool = optee_ffa_shm_pool_alloc_pages();
        if (IS_ERR(pool)) {
                rc = PTR_ERR(pool);
                goto err_free_optee;
        }
        optee->pool = pool;

        optee->ops = &optee_ffa_ops;
        optee->ffa.ffa_dev = ffa_dev;
        optee->ffa.bottom_half_value = U32_MAX;
        optee->rpc_param_count = rpc_param_count;

        if (IS_REACHABLE(CONFIG_RPMB) &&
            (sec_caps & OPTEE_FFA_SEC_CAP_RPMB_PROBE))
                optee->in_kernel_rpmb_routing = true;

        teedev = tee_device_alloc(&optee_ffa_clnt_desc, NULL, optee->pool,
                                  optee);
        if (IS_ERR(teedev)) {
                rc = PTR_ERR(teedev);
                goto err_free_pool;
        }
        optee->teedev = teedev;

        teedev = tee_device_alloc(&optee_ffa_supp_desc, NULL, optee->pool,
                                  optee);
        if (IS_ERR(teedev)) {
                rc = PTR_ERR(teedev);
                goto err_unreg_teedev;
        }
        optee->supp_teedev = teedev;

        optee_set_dev_group(optee);

        rc = tee_device_register(optee->teedev);
        if (rc)
                goto err_unreg_supp_teedev;

        rc = tee_device_register(optee->supp_teedev);
        if (rc)
                goto err_unreg_supp_teedev;

        rc = rhashtable_init(&optee->ffa.global_ids, &shm_rhash_params);
        if (rc)
                goto err_unreg_supp_teedev;
        mutex_init(&optee->ffa.mutex);
        optee_cq_init(&optee->call_queue, 0);
        optee_supp_init(&optee->supp);
        optee_shm_arg_cache_init(optee, arg_cache_flags);
        mutex_init(&optee->rpmb_dev_mutex);
        ffa_dev_set_drvdata(ffa_dev, optee);
        ctx = teedev_open(optee->teedev);
        if (IS_ERR(ctx)) {
                rc = PTR_ERR(ctx);
                goto err_rhashtable_free;
        }
        optee->ctx = ctx;
        rc = optee_notif_init(optee, OPTEE_DEFAULT_MAX_NOTIF_VALUE);
        if (rc)
                goto err_close_ctx;
        if (sec_caps & OPTEE_FFA_SEC_CAP_ASYNC_NOTIF) {
                rc = optee_ffa_async_notif_init(ffa_dev, optee);
                if (rc < 0)
                        pr_err("Failed to initialize async notifications: %d",
                               rc);
        }

        rc = optee_enumerate_devices(PTA_CMD_GET_DEVICES);
        if (rc)
                goto err_unregister_devices;

        INIT_WORK(&optee->rpmb_scan_bus_work, optee_bus_scan_rpmb);
        optee->rpmb_intf.notifier_call = optee_rpmb_intf_rdev;
        blocking_notifier_chain_register(&optee_rpmb_intf_added,
                                         &optee->rpmb_intf);
        pr_info("initialized driver\n");
        return 0;

err_unregister_devices:
        optee_unregister_devices();
        if (optee->ffa.bottom_half_value != U32_MAX)
                notif_ops->notify_relinquish(ffa_dev,
                                             optee->ffa.bottom_half_value);
        optee_notif_uninit(optee);
err_close_ctx:
        teedev_close_context(ctx);
err_rhashtable_free:
        rhashtable_free_and_destroy(&optee->ffa.global_ids, rh_free_fn, NULL);
        rpmb_dev_put(optee->rpmb_dev);
        mutex_destroy(&optee->rpmb_dev_mutex);
        optee_supp_uninit(&optee->supp);
        mutex_destroy(&optee->call_queue.mutex);
        mutex_destroy(&optee->ffa.mutex);
err_unreg_supp_teedev:
        tee_device_unregister(optee->supp_teedev);
err_unreg_teedev:
        tee_device_unregister(optee->teedev);
err_free_pool:
        tee_shm_pool_free(pool);
err_free_optee:
        kfree(optee);
        return rc;
}

static const struct ffa_device_id optee_ffa_device_id[] = {
        /* 486178e0-e7f8-11e3-bc5e0002a5d5c51b */
        { UUID_INIT(0x486178e0, 0xe7f8, 0x11e3,
                    0xbc, 0x5e, 0x00, 0x02, 0xa5, 0xd5, 0xc5, 0x1b) },
        {}
};

static struct ffa_driver optee_ffa_driver = {
        .name = "optee",
        .probe = optee_ffa_probe,
        .remove = optee_ffa_remove,
        .id_table = optee_ffa_device_id,
};

int optee_ffa_abi_register(void)
{
        if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT))
                return ffa_register(&optee_ffa_driver);
        else
                return -EOPNOTSUPP;
}

void optee_ffa_abi_unregister(void)
{
        if (IS_REACHABLE(CONFIG_ARM_FFA_TRANSPORT))
                ffa_unregister(&optee_ffa_driver);
}