text: // SPDX-License-Identifier: BSD-2-Clause
  /*
   * Copyright (c) 2016-2020, Linaro Limited
   * Copyright (c) 2014, STMicroelectronics International N.V.
   */
  #include <arm.h>
  #include <compiler.h>
  #include <config.h>
  #include <kernel/misc.h>
  #include <kernel/thread.h>
  #include <platform_config.h>
  #include <sm/optee_smc.h>
  #include <sm/sm.h>
  #include <sm/std_smc.h>
  #include <string.h>
  #include "sm_private.h"
  
  enum sm_handler_ret __weak sm_platform_handler(struct sm_ctx *ctx __unused)
  {
  	return SM_HANDLER_PENDING_SMC;
  }
  
  static void smc_arch_handler(struct thread_smc_args *args)
  {
  	uint32_t smc_fid = args->a0;
  	uint32_t feature_fid = args->a1;
  
  	switch (smc_fid) {
  	case ARM_SMCCC_VERSION:
  		args->a0 = SMCCC_V_1_1;
  		break;
  	case ARM_SMCCC_ARCH_FEATURES:
  		switch (feature_fid) {
  		case ARM_SMCCC_VERSION:
  		case ARM_SMCCC_ARCH_SOC_ID:
  			args->a0 = ARM_SMCCC_RET_SUCCESS;
  			break;
  		default:
  			args->a0 = ARM_SMCCC_RET_NOT_SUPPORTED;
  			break;
  		}
  		break;
  	case ARM_SMCCC_ARCH_SOC_ID:
  		args->a0 = ARM_SMCCC_RET_NOT_SUPPORTED;
  		break;
  	case ARM_SMCCC_ARCH_WORKAROUND_1:
  	case ARM_SMCCC_ARCH_WORKAROUND_2:
  		args->a0 = ARM_SMCCC_RET_NOT_REQUIRED;
  		break;
  	default:
  		args->a0 = OPTEE_SMC_RETURN_UNKNOWN_FUNCTION;
  		break;
  	}
  }
  
  uint32_t sm_from_nsec(struct sm_ctx *ctx)
  {
  	uint32_t *nsec_r0 = (uint32_t *)(&ctx->nsec.r0);
  	struct thread_smc_args *args = (struct thread_smc_args *)nsec_r0;
  
  	/*
  	 * Check that struct sm_ctx has the different parts properly
  	 * aligned since the stack pointer will be updated to point at
  	 * different parts of this struct.
  	 */
  	COMPILE_TIME_ASSERT(!(offsetof(struct sm_ctx, sec.r0) % 8));
  	COMPILE_TIME_ASSERT(!(offsetof(struct sm_ctx, nsec.r0) % 8));
  	COMPILE_TIME_ASSERT(!(sizeof(struct sm_ctx) % 8));
  
  	if (IS_ENABLED(CFG_SM_PLATFORM_HANDLER) &&
  	    sm_platform_handler(ctx) == SM_HANDLER_SMC_HANDLED)
  		return SM_EXIT_TO_NON_SECURE;
  
  	switch (OPTEE_SMC_OWNER_NUM(args->a0)) {
  	case OPTEE_SMC_OWNER_STANDARD:
  		if (IS_ENABLED(CFG_PSCI_ARM32)) {
  			smc_std_handler(args, &ctx->nsec);
  			return SM_EXIT_TO_NON_SECURE;
  		}
  		break;
  	case OPTEE_SMC_OWNER_ARCH:
  		smc_arch_handler(args);
  		return SM_EXIT_TO_NON_SECURE;
  	default:
  		break;
  	}
  
  	sm_save_unbanked_regs(&ctx->nsec.ub_regs);
  	sm_restore_unbanked_regs(&ctx->sec.ub_regs);
  
  	memcpy(&ctx->sec.r0, args, sizeof(*args));
  	if (OPTEE_SMC_IS_FAST_CALL(ctx->sec.r0))
  		ctx->sec.mon_lr = (uint32_t)&thread_vector_table.fast_smc_entry;
  	else
  		ctx->sec.mon_lr = (uint32_t)&thread_vector_table.std_smc_entry;
  
  	return SM_EXIT_TO_SECURE;
  }
  