LXR linux/drivers/tee/optee/device.c

   1// SPDX-License-Identifier: GPL-2.0
   2/*
   3 * Copyright (C) 2019 Linaro Ltd.
   4 */
   5
   6#define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
   7
   8#include <linux/kernel.h>
   9#include <linux/slab.h>
  10#include <linux/tee_drv.h>
  11#include <linux/uuid.h>
  12#include "optee_private.h"
  13
  14static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
  15{
  16        if (ver->impl_id == TEE_IMPL_ID_OPTEE)
  17                return 1;
  18        else
  19                return 0;
  20}
  21
  22static int get_devices(struct tee_context *ctx, u32 session,
  23                       struct tee_shm *device_shm, u32 *shm_size,
  24                       u32 func)
  25{
  26        int ret = 0;
  27        struct tee_ioctl_invoke_arg inv_arg;
  28        struct tee_param param[4];
  29
  30        memset(&inv_arg, 0, sizeof(inv_arg));
  31        memset(&param, 0, sizeof(param));
  32
  33        inv_arg.func = func;
  34        inv_arg.session = session;
  35        inv_arg.num_params = 4;
  36
  37        /* Fill invoke cmd params */
  38        param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
  39        param[0].u.memref.shm = device_shm;
  40        param[0].u.memref.size = *shm_size;
  41        param[0].u.memref.shm_offs = 0;
  42
  43        ret = tee_client_invoke_func(ctx, &inv_arg, param);
  44        if ((ret < 0) || ((inv_arg.ret != TEEC_SUCCESS) &&
  45                          (inv_arg.ret != TEEC_ERROR_SHORT_BUFFER))) {
  46                pr_err("PTA_CMD_GET_DEVICES invoke function err: %x\n",
  47                       inv_arg.ret);
  48                return -EINVAL;
  49        }
  50
  51        *shm_size = param[0].u.memref.size;
  52
  53        return 0;
  54}
  55
  56static void optee_release_device(struct device *dev)
  57{
  58        struct tee_client_device *optee_device = to_tee_client_device(dev);
  59
  60        kfree(optee_device);
  61}
  62
  63static int optee_register_device(const uuid_t *device_uuid)
  64{
  65        struct tee_client_device *optee_device = NULL;
  66        int rc;
  67
  68        optee_device = kzalloc(sizeof(*optee_device), GFP_KERNEL);
  69        if (!optee_device)
  70                return -ENOMEM;
  71
  72        optee_device->dev.bus = &tee_bus_type;
  73        optee_device->dev.release = optee_release_device;
  74        if (dev_set_name(&optee_device->dev, "optee-ta-%pUb", device_uuid)) {
  75                kfree(optee_device);
  76                return -ENOMEM;
  77        }
  78        uuid_copy(&optee_device->id.uuid, device_uuid);
  79
  80        rc = device_register(&optee_device->dev);
  81        if (rc) {
  82                pr_err("device registration failed, err: %d\n", rc);
  83                kfree(optee_device);
  84        }
  85
  86        return rc;
  87}
  88
  89static int __optee_enumerate_devices(u32 func)
  90{
  91        const uuid_t pta_uuid =
  92                UUID_INIT(0x7011a688, 0xddde, 0x4053,
  93                          0xa5, 0xa9, 0x7b, 0x3c, 0x4d, 0xdf, 0x13, 0xb8);
  94        struct tee_ioctl_open_session_arg sess_arg;
  95        struct tee_shm *device_shm = NULL;
  96        const uuid_t *device_uuid = NULL;
  97        struct tee_context *ctx = NULL;
  98        u32 shm_size = 0, idx, num_devices = 0;
  99        int rc;
 100
 101        memset(&sess_arg, 0, sizeof(sess_arg));
 102
 103        /* Open context with OP-TEE driver */
 104        ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
 105        if (IS_ERR(ctx))
 106                return -ENODEV;
 107
 108        /* Open session with device enumeration pseudo TA */
 109        export_uuid(sess_arg.uuid, &pta_uuid);
 110        sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
 111        sess_arg.num_params = 0;
 112
 113        rc = tee_client_open_session(ctx, &sess_arg, NULL);
 114        if ((rc < 0) || (sess_arg.ret != TEEC_SUCCESS)) {
 115                /* Device enumeration pseudo TA not found */
 116                rc = 0;
 117                goto out_ctx;
 118        }
 119
 120        rc = get_devices(ctx, sess_arg.session, NULL, &shm_size, func);
 121        if (rc < 0 || !shm_size)
 122                goto out_sess;
 123
 124        device_shm = tee_shm_alloc(ctx, shm_size,
 125                                   TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
 126        if (IS_ERR(device_shm)) {
 127                pr_err("tee_shm_alloc failed\n");
 128                rc = PTR_ERR(device_shm);
 129                goto out_sess;
 130        }
 131
 132        rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size, func);
 133        if (rc < 0)
 134                goto out_shm;
 135
 136        device_uuid = tee_shm_get_va(device_shm, 0);
 137        if (IS_ERR(device_uuid)) {
 138                pr_err("tee_shm_get_va failed\n");
 139                rc = PTR_ERR(device_uuid);
 140                goto out_shm;
 141        }
 142
 143        num_devices = shm_size / sizeof(uuid_t);
 144
 145        for (idx = 0; idx < num_devices; idx++) {
 146                rc = optee_register_device(&device_uuid[idx]);
 147                if (rc)
 148                        goto out_shm;
 149        }
 150
 151out_shm:
 152        tee_shm_free(device_shm);
 153out_sess:
 154        tee_client_close_session(ctx, sess_arg.session);
 155out_ctx:
 156        tee_client_close_context(ctx);
 157
 158        return rc;
 159}
 160
 161int optee_enumerate_devices(u32 func)
 162{
 163        return  __optee_enumerate_devices(func);
 164}
 165
 166static int __optee_unregister_device(struct device *dev, void *data)
 167{
 168        if (!strncmp(dev_name(dev), "optee-ta", strlen("optee-ta")))
 169                device_unregister(dev);
 170
 171        return 0;
 172}
 173
 174void optee_unregister_devices(void)
 175{
 176        bus_for_each_dev(&tee_bus_type, NULL, NULL,
 177                         __optee_unregister_device);
 178}
 179