--- zzzz-none-000/linux-4.19.183/drivers/tee/optee/core.c	2021-03-24 10:07:39.000000000 +0000
+++ bcm63-7530ax-756/linux-4.19.183/drivers/tee/optee/core.c	2023-06-28 08:54:20.000000000 +0000
@@ -517,7 +517,37 @@
 			    unsigned long a6, unsigned long a7,
 			    struct arm_smccc_res *res)
 {
+#if defined(CONFIG_BCM_KF_OPTEE)
+	extern char _stext[], _etext[];
+#if defined(CONFIG_ARM64)
+	register long ret_addr asm ("x30");
+
+	/* Make SMC call and save x0-x3 into res */
+	__asm__ volatile(
+					"smc #0                    \n"
+					"mov x8, %0                \n"
+					"stp x0, x1, [x8]          \n"
+					"stp x2, x3, [x8, #0x10]   \n"
+					: : "r" (res) : "x8");
+#else
+	register long ret_addr asm ("r14");
+
+	/* Make SMC call (opcode: 0xE1600070) and save r0-r3 into res */
+	__asm__ volatile(
+					".long 0xE1600070          \n"
+					"mov r8, %0                \n"
+					"stm r8, {r0-r3}           \n"
+					: : "r" (res) : "r8");
+#endif
+	/* Make sure, this function was called from signed address range */
+	if ( (char*)ret_addr < _stext || (char*)ret_addr > _etext){
+		pr_info("ALERT!! System intrution detected by OP-TEE\n");
+		res->a0 = OPTEE_SMC_RETURN_UNKNOWN_FUNCTION;
+		return;
+	}
+#else
 	arm_smccc_smc(a0, a1, a2, a3, a4, a5, a6, a7, res);
+#endif
 }
 
 static void optee_smccc_hvc(unsigned long a0, unsigned long a1,
@@ -549,7 +579,11 @@
 	return ERR_PTR(-EINVAL);
 }
 
+#if defined(CONFIG_BCM_KF_OPTEE)
+struct optee *optee_probe(struct device_node *np)
+#else
 static struct optee *optee_probe(struct device_node *np)
+#endif
 {
 	optee_invoke_fn *invoke_fn;
 	struct tee_shm_pool *pool;