arm/arm64: Make use of the SMCCC 1.1 wrapper

mainline inclusion
from mainline-v5.8-rc5
commit ce4d5ca2b9dd5d85944eb93c1bbf9eb11b7a907d
category: feature
bugzilla: NA
CVE: NA

--------------------------------

Rather than directly choosing which function to use based on
psci_ops.conduit, use the new arm_smccc_1_1 wrapper instead.

In some cases we still need to do some operations based on the
conduit, but the code duplication is removed.

No functional change.
Signed-off-by: NSteven Price <steven.price@arm.com>
Signed-off-by: NMarc Zyngier <maz@kernel.org>
Reviewed-by: Nzhanghailiang <zhang.zhanghailiang@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

arch/arm/mm/proc-v7-bugs.c

@@ -81,12 +81,13 @@ static void cpu_v7_spectre_init(void)
 		if (psci_ops.smccc_version == SMCCC_VERSION_1_0)
 			break;
 
+		arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+				     ARM_SMCCC_ARCH_WORKAROUND_1, &res);
+		if ((int)res.a0 != 0)
+			return;
+
 		switch (psci_ops.conduit) {
 		case PSCI_CONDUIT_HVC:
-			arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
-					  ARM_SMCCC_ARCH_WORKAROUND_1, &res);
-			if ((int)res.a0 != 0)
-				break;
 			per_cpu(harden_branch_predictor_fn, cpu) =
 				call_hvc_arch_workaround_1;
 			cpu_do_switch_mm = cpu_v7_hvc_switch_mm;
@@ -94,10 +95,6 @@ static void cpu_v7_spectre_init(void)
 			break;
 
 		case PSCI_CONDUIT_SMC:
-			arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
-					  ARM_SMCCC_ARCH_WORKAROUND_1, &res);
-			if ((int)res.a0 != 0)
-				break;
 			per_cpu(harden_branch_predictor_fn, cpu) =
 				call_smc_arch_workaround_1;
 			cpu_do_switch_mm = cpu_v7_smc_switch_mm;

arch/arm64/kernel/cpu_errata.c

@@ -217,40 +217,31 @@ static int detect_harden_bp_fw(void)
 	if (psci_ops.smccc_version == SMCCC_VERSION_1_0)
 		return -1;
 
+	arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+			     ARM_SMCCC_ARCH_WORKAROUND_1, &res);
+
+	switch ((int)res.a0) {
+	case 1:
+		/* Firmware says we're just fine */
+		return 0;
+	case 0:
+		break;
+	default:
+		return -1;
+	}
+
 	switch (psci_ops.conduit) {
 	case PSCI_CONDUIT_HVC:
-		arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
-				  ARM_SMCCC_ARCH_WORKAROUND_1, &res);
-		switch ((int)res.a0) {
-		case 1:
-			/* Firmware says we're just fine */
-			return 0;
-		case 0:
-			cb = call_hvc_arch_workaround_1;
-			/* This is a guest, no need to patch KVM vectors */
-			smccc_start = NULL;
-			smccc_end = NULL;
-			break;
-		default:
-			return -1;
-		}
+		cb = call_hvc_arch_workaround_1;
+		/* This is a guest, no need to patch KVM vectors */
+		smccc_start = NULL;
+		smccc_end = NULL;
 		break;
 
 	case PSCI_CONDUIT_SMC:
-		arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
-				  ARM_SMCCC_ARCH_WORKAROUND_1, &res);
-		switch ((int)res.a0) {
-		case 1:
-			/* Firmware says we're just fine */
-			return 0;
-		case 0:
-			cb = call_smc_arch_workaround_1;
-			smccc_start = __smccc_workaround_1_smc_start;
-			smccc_end = __smccc_workaround_1_smc_end;
-			break;
-		default:
-			return -1;
-		}
+		cb = call_smc_arch_workaround_1;
+		smccc_start = __smccc_workaround_1_smc_start;
+		smccc_end = __smccc_workaround_1_smc_end;
 		break;
 
 	default:
@@ -340,6 +331,8 @@ void __init arm64_enable_wa2_handling(struct alt_instr *alt,
 
 void arm64_set_ssbd_mitigation(bool state)
 {
+	int conduit;
+
 	if (!IS_ENABLED(CONFIG_ARM64_SSBD)) {
 		pr_info_once("SSBD disabled by kernel configuration\n");
 		return;
@@ -353,19 +346,9 @@ void arm64_set_ssbd_mitigation(bool state)
 		return;
 	}
 
-	switch (psci_ops.conduit) {
-	case PSCI_CONDUIT_HVC:
-		arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_2, state, NULL);
-		break;
-
-	case PSCI_CONDUIT_SMC:
-		arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, state, NULL);
-		break;
-
-	default:
-		WARN_ON_ONCE(1);
-		break;
-	}
+	conduit = arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_WORKAROUND_2, state,
+				       NULL);
+	WARN_ON_ONCE(conduit == PSCI_CONDUIT_NONE);
 }
 
 static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
@@ -375,6 +358,7 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
 	bool required = true;
 	s32 val;
 	bool this_cpu_safe = false;
+	int conduit;
 
 	WARN_ON(scope != SCOPE_LOCAL_CPU || preemptible());
 
@@ -399,18 +383,10 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
 		return false;
 	}
 
-	switch (psci_ops.conduit) {
-	case PSCI_CONDUIT_HVC:
-		arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
-				  ARM_SMCCC_ARCH_WORKAROUND_2, &res);
-		break;
+	conduit = arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
+				       ARM_SMCCC_ARCH_WORKAROUND_2, &res);
 
-	case PSCI_CONDUIT_SMC:
-		arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
-				  ARM_SMCCC_ARCH_WORKAROUND_2, &res);
-		break;
-
-	default:
+	if (conduit == PSCI_CONDUIT_NONE) {
 		ssbd_state = ARM64_SSBD_UNKNOWN;
 		if (!this_cpu_safe)
 			__ssb_safe = false;