[PATCH] x86/cpu/intel: clean up detect_sgx() flow

[Jarkko Sakkinen]

Signed-off-by: Jarkko Sakkinen <jarkko.sakkinen@xxxxxxxxxxxxxxx>
---
 arch/x86/kernel/cpu/intel.c | 32 ++++++++++++++++++++------------
 1 file changed, 20 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index bc52c52f7025..8a20a193d399 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -598,28 +598,36 @@ static void detect_tme(struct cpuinfo_x86 *c)
 
 static void detect_sgx(struct cpuinfo_x86 *c)
 {
-	bool unsupported = false;
 	unsigned long long fc;
 
 	rdmsrl(MSR_IA32_FEATURE_CONTROL, fc);
 	if (!(fc & FEATURE_CONTROL_LOCKED)) {
 		pr_err_once("sgx: IA32_FEATURE_CONTROL MSR is not locked\n");
-		unsupported = true;
-	} else if (!(fc & FEATURE_CONTROL_SGX_ENABLE)) {
+		goto out_unsupported;
+	}
+
+	if (!(fc & FEATURE_CONTROL_SGX_ENABLE)) {
 		pr_err_once("sgx: not enabled in IA32_FEATURE_CONTROL MSR\n");
-		unsupported = true;
-	} else if (!cpu_has(c, X86_FEATURE_SGX1)) {
+		goto out_unsupported;
+	}
+
+	if (!cpu_has(c, X86_FEATURE_SGX1)) {
 		pr_err_once("sgx: SGX1 instruction set not supported\n");
-		unsupported = true;
+		goto out_unsupported;
 	}
 
-	if (unsupported) {
-		setup_clear_cpu_cap(X86_FEATURE_SGX);
-		setup_clear_cpu_cap(X86_FEATURE_SGX1);
-		setup_clear_cpu_cap(X86_FEATURE_SGX2);
+	if (!(fc & FEATURE_CONTROL_SGX_LE_WR)) {
+		pr_info_once("sgx: launch control MSRs are not writable\n");
+		goto out_msrs_rdonly;
 	}
-	if (unsupported || !(fc & FEATURE_CONTROL_SGX_LE_WR))
-		setup_clear_cpu_cap(X86_FEATURE_SGX_LC);
+
+	return;
+out_unsupported:
+	setup_clear_cpu_cap(X86_FEATURE_SGX);
+	setup_clear_cpu_cap(X86_FEATURE_SGX1);
+	setup_clear_cpu_cap(X86_FEATURE_SGX2);
+out_msrs_rdonly:
+	setup_clear_cpu_cap(X86_FEATURE_SGX_LC);
 }
 
 static void init_intel_energy_perf(struct cpuinfo_x86 *c)
-- 
2.19.1


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