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arm/arm64: Make use of the SMCCC 1.1 wrapper
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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: Steven Price <steven.price@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Steven Price authored and Marc Zyngier committed Oct 21, 2019
1 parent 541625a commit ce4d5ca
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Showing 2 changed files with 34 additions and 60 deletions.
13 changes: 5 additions & 8 deletions arch/arm/mm/proc-v7-bugs.c
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Original file line number Diff line number Diff line change
Expand Up @@ -74,23 +74,20 @@ static void cpu_v7_spectre_init(void)
case ARM_CPU_PART_CORTEX_A72: {
struct arm_smccc_res res;

arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
ARM_SMCCC_ARCH_WORKAROUND_1, &res);
if ((int)res.a0 != 0)
return;

switch (arm_smccc_1_1_get_conduit()) {
case SMCCC_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;
spectre_v2_method = "hypervisor";
break;

case SMCCC_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;
Expand Down
81 changes: 29 additions & 52 deletions arch/arm64/kernel/cpu_errata.c
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Original file line number Diff line number Diff line change
Expand Up @@ -209,40 +209,31 @@ static int detect_harden_bp_fw(void)
struct arm_smccc_res res;
u32 midr = read_cpuid_id();

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 (arm_smccc_1_1_get_conduit()) {
case SMCCC_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 SMCCC_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:
Expand Down Expand Up @@ -332,6 +323,8 @@ 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;
Expand All @@ -345,19 +338,10 @@ void arm64_set_ssbd_mitigation(bool state)
return;
}

switch (arm_smccc_1_1_get_conduit()) {
case SMCCC_CONDUIT_HVC:
arm_smccc_1_1_hvc(ARM_SMCCC_ARCH_WORKAROUND_2, state, NULL);
break;

case SMCCC_CONDUIT_SMC:
arm_smccc_1_1_smc(ARM_SMCCC_ARCH_WORKAROUND_2, state, NULL);
break;
conduit = arm_smccc_1_1_invoke(ARM_SMCCC_ARCH_WORKAROUND_2, state,
NULL);

default:
WARN_ON_ONCE(1);
break;
}
WARN_ON_ONCE(conduit == SMCCC_CONDUIT_NONE);
}

static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
Expand All @@ -367,6 +351,7 @@ 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());

Expand All @@ -384,18 +369,10 @@ static bool has_ssbd_mitigation(const struct arm64_cpu_capabilities *entry,
goto out_printmsg;
}

switch (arm_smccc_1_1_get_conduit()) {
case SMCCC_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 SMCCC_CONDUIT_SMC:
arm_smccc_1_1_smc(ARM_SMCCC_ARCH_FEATURES_FUNC_ID,
ARM_SMCCC_ARCH_WORKAROUND_2, &res);
break;

default:
if (conduit == SMCCC_CONDUIT_NONE) {
ssbd_state = ARM64_SSBD_UNKNOWN;
if (!this_cpu_safe)
__ssb_safe = false;
Expand Down

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