arch/arm/mach-at91/sam_secure.c

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  * Copyright (C) 2022, Microchip
   4  */
   5
   6 #include <linux/arm-smccc.h>
   7 #include <linux/of.h>
   8
   9 #include "sam_secure.h"
  10
  11 static bool optee_available;
  12
  13 #define SAM_SIP_SMC_STD_CALL_VAL(func_num) \
  14         ARM_SMCCC_CALL_VAL(ARM_SMCCC_STD_CALL, ARM_SMCCC_SMC_32, \
  15         ARM_SMCCC_OWNER_SIP, (func_num))
  16
  17 struct arm_smccc_res sam_smccc_call(u32 fn, u32 arg0, u32 arg1)
  18 {
  19         struct arm_smccc_res res = {.a0 = -1};
  20
  21         if (WARN_ON(!optee_available))
  22                 return res;
  23
  24         arm_smccc_smc(SAM_SIP_SMC_STD_CALL_VAL(fn), arg0, arg1, 0, 0, 0, 0, 0,
  25                       &res);
  26
  27         return res;
  28 }
  29
  30 bool sam_linux_is_optee_available(void)
  31 {
  32         /* If optee has been detected, then we are running in normal world */
  33         return optee_available;
  34 }
  35
  36 void __init sam_secure_init(void)
  37 {
  38         struct device_node *np;
  39
  40         /*
  41          * We only check that the OP-TEE node is present and available. The
  42          * OP-TEE kernel driver is not needed for the type of interaction made
  43          * with OP-TEE here so the driver's status is not checked.
  44          */
  45         np = of_find_node_by_path("/firmware/optee");
  46         if (np && of_device_is_available(np))
  47                 optee_available = true;
  48         of_node_put(np);
  49
  50         if (optee_available)
  51                 pr_info("Running under OP-TEE firmware\n");
  52 }