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_core.h>
  11 #include <linux/uuid.h>
  12 #include "optee_private.h"
  13
  14 static 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
  22 static 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                 /*
  47                  * TEE_ERROR_STORAGE_NOT_AVAILABLE is returned when getting
  48                  * the list of device TAs that depends on RPMB but a usable
  49                  * RPMB device isn't found.
  50                  */
  51                 if (inv_arg.ret == TEE_ERROR_STORAGE_NOT_AVAILABLE)
  52                         return -ENODEV;
  53                 pr_err("PTA_CMD_GET_DEVICES invoke function err: %x\n",
  54                        inv_arg.ret);
  55                 return -EINVAL;
  56         }
  57
  58         *shm_size = param[0].u.memref.size;
  59
  60         return 0;
  61 }
  62
  63 static void optee_release_device(struct device *dev)
  64 {
  65         struct tee_client_device *optee_device = to_tee_client_device(dev);
  66
  67         kfree(optee_device);
  68 }
  69
  70 static ssize_t need_supplicant_show(struct device *dev,
  71                                     struct device_attribute *attr,
  72                                     char *buf)
  73 {
  74         return 0;
  75 }
  76
  77 static DEVICE_ATTR_RO(need_supplicant);
  78
  79 static int optee_register_device(const uuid_t *device_uuid, u32 func)
  80 {
  81         struct tee_client_device *optee_device = NULL;
  82         int rc;
  83
  84         optee_device = kzalloc(sizeof(*optee_device), GFP_KERNEL);
  85         if (!optee_device)
  86                 return -ENOMEM;
  87
  88         optee_device->dev.bus = &tee_bus_type;
  89         optee_device->dev.release = optee_release_device;
  90         if (dev_set_name(&optee_device->dev, "optee-ta-%pUb", device_uuid)) {
  91                 kfree(optee_device);
  92                 return -ENOMEM;
  93         }
  94         uuid_copy(&optee_device->id.uuid, device_uuid);
  95
  96         rc = device_register(&optee_device->dev);
  97         if (rc) {
  98                 pr_err("device registration failed, err: %d\n", rc);
  99                 put_device(&optee_device->dev);
 100                 return rc;
 101         }
 102
 103         if (func == PTA_CMD_GET_DEVICES_SUPP)
 104                 device_create_file(&optee_device->dev,
 105                                    &dev_attr_need_supplicant);
 106
 107         return 0;
 108 }
 109
 110 static int __optee_enumerate_devices(u32 func)
 111 {
 112         const uuid_t pta_uuid =
 113                 UUID_INIT(0x7011a688, 0xddde, 0x4053,
 114                           0xa5, 0xa9, 0x7b, 0x3c, 0x4d, 0xdf, 0x13, 0xb8);
 115         struct tee_ioctl_open_session_arg sess_arg;
 116         struct tee_shm *device_shm = NULL;
 117         const uuid_t *device_uuid = NULL;
 118         struct tee_context *ctx = NULL;
 119         u32 shm_size = 0, idx, num_devices = 0;
 120         int rc;
 121
 122         memset(&sess_arg, 0, sizeof(sess_arg));
 123
 124         /* Open context with OP-TEE driver */
 125         ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
 126         if (IS_ERR(ctx))
 127                 return -ENODEV;
 128
 129         /* Open session with device enumeration pseudo TA */
 130         export_uuid(sess_arg.uuid, &pta_uuid);
 131         sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
 132         sess_arg.num_params = 0;
 133
 134         rc = tee_client_open_session(ctx, &sess_arg, NULL);
 135         if ((rc < 0) || (sess_arg.ret != TEEC_SUCCESS)) {
 136                 /* Device enumeration pseudo TA not found */
 137                 rc = 0;
 138                 goto out_ctx;
 139         }
 140
 141         rc = get_devices(ctx, sess_arg.session, NULL, &shm_size, func);
 142         if (rc < 0 || !shm_size)
 143                 goto out_sess;
 144
 145         device_shm = tee_shm_alloc_kernel_buf(ctx, shm_size);
 146         if (IS_ERR(device_shm)) {
 147                 pr_err("tee_shm_alloc_kernel_buf failed\n");
 148                 rc = PTR_ERR(device_shm);
 149                 goto out_sess;
 150         }
 151
 152         rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size, func);
 153         if (rc < 0)
 154                 goto out_shm;
 155
 156         device_uuid = tee_shm_get_va(device_shm, 0);
 157         if (IS_ERR(device_uuid)) {
 158                 pr_err("tee_shm_get_va failed\n");
 159                 rc = PTR_ERR(device_uuid);
 160                 goto out_shm;
 161         }
 162
 163         num_devices = shm_size / sizeof(uuid_t);
 164
 165         for (idx = 0; idx < num_devices; idx++) {
 166                 rc = optee_register_device(&device_uuid[idx], func);
 167                 if (rc)
 168                         goto out_shm;
 169         }
 170
 171 out_shm:
 172         tee_shm_free(device_shm);
 173 out_sess:
 174         tee_client_close_session(ctx, sess_arg.session);
 175 out_ctx:
 176         tee_client_close_context(ctx);
 177
 178         return rc;
 179 }
 180
 181 int optee_enumerate_devices(u32 func)
 182 {
 183         return  __optee_enumerate_devices(func);
 184 }
 185
 186 static int __optee_unregister_device(struct device *dev, void *data)
 187 {
 188         if (!strncmp(dev_name(dev), "optee-ta", strlen("optee-ta")))
 189                 device_unregister(dev);
 190
 191         return 0;
 192 }
 193
 194 void optee_unregister_devices(void)
 195 {
 196         bus_for_each_dev(&tee_bus_type, NULL, NULL,
 197                          __optee_unregister_device);
 198 }