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
  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                 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
  56 static 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
  63 static 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                 put_device(&optee_device->dev);
  84         }
  85
  86         return rc;
  87 }
  88
  89 static 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_kernel_buf(ctx, shm_size);
 125         if (IS_ERR(device_shm)) {
 126                 pr_err("tee_shm_alloc_kernel_buf failed\n");
 127                 rc = PTR_ERR(device_shm);
 128                 goto out_sess;
 129         }
 130
 131         rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size, func);
 132         if (rc < 0)
 133                 goto out_shm;
 134
 135         device_uuid = tee_shm_get_va(device_shm, 0);
 136         if (IS_ERR(device_uuid)) {
 137                 pr_err("tee_shm_get_va failed\n");
 138                 rc = PTR_ERR(device_uuid);
 139                 goto out_shm;
 140         }
 141
 142         num_devices = shm_size / sizeof(uuid_t);
 143
 144         for (idx = 0; idx < num_devices; idx++) {
 145                 rc = optee_register_device(&device_uuid[idx]);
 146                 if (rc)
 147                         goto out_shm;
 148         }
 149
 150 out_shm:
 151         tee_shm_free(device_shm);
 152 out_sess:
 153         tee_client_close_session(ctx, sess_arg.session);
 154 out_ctx:
 155         tee_client_close_context(ctx);
 156
 157         return rc;
 158 }
 159
 160 int optee_enumerate_devices(u32 func)
 161 {
 162         return  __optee_enumerate_devices(func);
 163 }
 164
 165 static int __optee_unregister_device(struct device *dev, void *data)
 166 {
 167         if (!strncmp(dev_name(dev), "optee-ta", strlen("optee-ta")))
 168                 device_unregister(dev);
 169
 170         return 0;
 171 }
 172
 173 void optee_unregister_devices(void)
 174 {
 175         bus_for_each_dev(&tee_bus_type, NULL, NULL,
 176                          __optee_unregister_device);
 177 }