x86/cpufeatures: Make SGX_LC feature bit depend on SGX bit

Move SGX_LC feature bit to CPUID dependency table to make clearing all
SGX feature bits easier. Also remove clear_sgx_caps() since it is just
a wrapper of setup_clear_cpu_cap(X86_FEATURE_SGX) now.

Suggested-by: Sean Christopherson <[email protected]>
Signed-off-by: Kai Huang <[email protected]>
Signed-off-by: Borislav Petkov <[email protected]>
Reviewed-by: Sean Christopherson <[email protected]>
Acked-by: Dave Hansen <[email protected]>
Acked-by: Jarkko Sakkinen <[email protected]>
Link: https://lkml.kernel.org/r/5d4220fd0a39f52af024d3fa166231c1d498dd10.1616136308.git.kai.huang@intel.com

Author: kaihuang

arch/x86/kernel/cpu/cpuid-deps.c

@@ -72,6 +72,7 @@ static const struct cpuid_dep cpuid_deps[] = {
 	{ X86_FEATURE_AVX512_FP16,		X86_FEATURE_AVX512BW  },
 	{ X86_FEATURE_ENQCMD,			X86_FEATURE_XSAVES    },
 	{ X86_FEATURE_PER_THREAD_MBA,		X86_FEATURE_MBA       },
+	{ X86_FEATURE_SGX_LC,			X86_FEATURE_SGX	      },
 	{}
 };
 

arch/x86/kernel/cpu/feat_ctl.c

@@ -93,15 +93,9 @@ static void init_vmx_capabilities(struct cpuinfo_x86 *c)
 }
 #endif /* CONFIG_X86_VMX_FEATURE_NAMES */
 
-static void clear_sgx_caps(void)
-{
-	setup_clear_cpu_cap(X86_FEATURE_SGX);
-	setup_clear_cpu_cap(X86_FEATURE_SGX_LC);
-}
-
 static int __init nosgx(char *str)
 {
-	clear_sgx_caps();
+	setup_clear_cpu_cap(X86_FEATURE_SGX);
 
 	return 0;
 }
@@ -116,7 +110,7 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
 
 	if (rdmsrl_safe(MSR_IA32_FEAT_CTL, &msr)) {
 		clear_cpu_cap(c, X86_FEATURE_VMX);
-		clear_sgx_caps();
+		clear_cpu_cap(c, X86_FEATURE_SGX);
 		return;
 	}
 
@@ -177,6 +171,6 @@ void init_ia32_feat_ctl(struct cpuinfo_x86 *c)
 	    !(msr & FEAT_CTL_SGX_LC_ENABLED) || !enable_sgx) {
 		if (enable_sgx)
 			pr_err_once("SGX disabled by BIOS\n");
-		clear_sgx_caps();
+		clear_cpu_cap(c, X86_FEATURE_SGX);
 	}
 }