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 /*
  15  * Get device UUIDs
  16  *
  17  * [out]     memref[0]        Array of device UUIDs
  18  *
  19  * Return codes:
  20  * TEE_SUCCESS - Invoke command success
  21  * TEE_ERROR_BAD_PARAMETERS - Incorrect input param
  22  * TEE_ERROR_SHORT_BUFFER - Output buffer size less than required
  23  */
  24 #define PTA_CMD_GET_DEVICES             0x0
  25
  26 static int optee_ctx_match(struct tee_ioctl_version_data *ver, const void *data)
  27 {
  28         if (ver->impl_id == TEE_IMPL_ID_OPTEE)
  29                 return 1;
  30         else
  31                 return 0;
  32 }
  33
  34 static int get_devices(struct tee_context *ctx, u32 session,
  35                        struct tee_shm *device_shm, u32 *shm_size)
  36 {
  37         int ret = 0;
  38         struct tee_ioctl_invoke_arg inv_arg;
  39         struct tee_param param[4];
  40
  41         memset(&inv_arg, 0, sizeof(inv_arg));
  42         memset(&param, 0, sizeof(param));
  43
  44         /* Invoke PTA_CMD_GET_DEVICES function */
  45         inv_arg.func = PTA_CMD_GET_DEVICES;
  46         inv_arg.session = session;
  47         inv_arg.num_params = 4;
  48
  49         /* Fill invoke cmd params */
  50         param[0].attr = TEE_IOCTL_PARAM_ATTR_TYPE_MEMREF_OUTPUT;
  51         param[0].u.memref.shm = device_shm;
  52         param[0].u.memref.size = *shm_size;
  53         param[0].u.memref.shm_offs = 0;
  54
  55         ret = tee_client_invoke_func(ctx, &inv_arg, param);
  56         if ((ret < 0) || ((inv_arg.ret != TEEC_SUCCESS) &&
  57                           (inv_arg.ret != TEEC_ERROR_SHORT_BUFFER))) {
  58                 pr_err("PTA_CMD_GET_DEVICES invoke function err: %x\n",
  59                        inv_arg.ret);
  60                 return -EINVAL;
  61         }
  62
  63         *shm_size = param[0].u.memref.size;
  64
  65         return 0;
  66 }
  67
  68 static int optee_register_device(const uuid_t *device_uuid, u32 device_id)
  69 {
  70         struct tee_client_device *optee_device = NULL;
  71         int rc;
  72
  73         optee_device = kzalloc(sizeof(*optee_device), GFP_KERNEL);
  74         if (!optee_device)
  75                 return -ENOMEM;
  76
  77         optee_device->dev.bus = &tee_bus_type;
  78         dev_set_name(&optee_device->dev, "optee-clnt%u", device_id);
  79         uuid_copy(&optee_device->id.uuid, device_uuid);
  80
  81         rc = device_register(&optee_device->dev);
  82         if (rc) {
  83                 pr_err("device registration failed, err: %d\n", rc);
  84                 kfree(optee_device);
  85         }
  86
  87         return rc;
  88 }
  89
  90 int optee_enumerate_devices(void)
  91 {
  92         const uuid_t pta_uuid =
  93                 UUID_INIT(0x7011a688, 0xddde, 0x4053,
  94                           0xa5, 0xa9, 0x7b, 0x3c, 0x4d, 0xdf, 0x13, 0xb8);
  95         struct tee_ioctl_open_session_arg sess_arg;
  96         struct tee_shm *device_shm = NULL;
  97         const uuid_t *device_uuid = NULL;
  98         struct tee_context *ctx = NULL;
  99         u32 shm_size = 0, idx, num_devices = 0;
 100         int rc;
 101
 102         memset(&sess_arg, 0, sizeof(sess_arg));
 103
 104         /* Open context with OP-TEE driver */
 105         ctx = tee_client_open_context(NULL, optee_ctx_match, NULL, NULL);
 106         if (IS_ERR(ctx))
 107                 return -ENODEV;
 108
 109         /* Open session with device enumeration pseudo TA */
 110         memcpy(sess_arg.uuid, pta_uuid.b, TEE_IOCTL_UUID_LEN);
 111         sess_arg.clnt_login = TEE_IOCTL_LOGIN_PUBLIC;
 112         sess_arg.num_params = 0;
 113
 114         rc = tee_client_open_session(ctx, &sess_arg, NULL);
 115         if ((rc < 0) || (sess_arg.ret != TEEC_SUCCESS)) {
 116                 /* Device enumeration pseudo TA not found */
 117                 rc = 0;
 118                 goto out_ctx;
 119         }
 120
 121         rc = get_devices(ctx, sess_arg.session, NULL, &shm_size);
 122         if (rc < 0 || !shm_size)
 123                 goto out_sess;
 124
 125         device_shm = tee_shm_alloc(ctx, shm_size,
 126                                    TEE_SHM_MAPPED | TEE_SHM_DMA_BUF);
 127         if (IS_ERR(device_shm)) {
 128                 pr_err("tee_shm_alloc failed\n");
 129                 rc = PTR_ERR(device_shm);
 130                 goto out_sess;
 131         }
 132
 133         rc = get_devices(ctx, sess_arg.session, device_shm, &shm_size);
 134         if (rc < 0)
 135                 goto out_shm;
 136
 137         device_uuid = tee_shm_get_va(device_shm, 0);
 138         if (IS_ERR(device_uuid)) {
 139                 pr_err("tee_shm_get_va failed\n");
 140                 rc = PTR_ERR(device_uuid);
 141                 goto out_shm;
 142         }
 143
 144         num_devices = shm_size / sizeof(uuid_t);
 145
 146         for (idx = 0; idx < num_devices; idx++) {
 147                 rc = optee_register_device(&device_uuid[idx], idx);
 148                 if (rc)
 149                         goto out_shm;
 150         }
 151
 152 out_shm:
 153         tee_shm_free(device_shm);
 154 out_sess:
 155         tee_client_close_session(ctx, sess_arg.session);
 156 out_ctx:
 157         tee_client_close_context(ctx);
 158
 159         return rc;
 160 }