[PATCH] x86/cpu/intel: Simplify detect_tme()

[Kirill A. Shutemov]

The detect_tme() function is now only called by the boot CPU. The logic
for cross-checking TME configuration between CPUs is no longer used. It
has never identified a real problem and can be safely removed.

The kernel does not use MKTME and is not concerned with MKTME policy or
encryption algorithms. There is no need to check them.

Signed-off-by: Kirill A. Shutemov <kirill.shutemov@xxxxxxxxxxxxxxx>
---
 arch/x86/kernel/cpu/intel.c | 44 ++-----------------------------------
 1 file changed, 2 insertions(+), 42 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel.c b/arch/x86/kernel/cpu/intel.c
index 4192aa4576f4..60918b49344c 100644
--- a/arch/x86/kernel/cpu/intel.c
+++ b/arch/x86/kernel/cpu/intel.c
@@ -329,55 +329,20 @@ static void early_init_intel(struct cpuinfo_x86 *c)
 #define TME_ACTIVATE_CRYPTO_ALGS(x)	((x >> 48) & 0xffff)	/* Bits 63:48 */
 #define TME_ACTIVATE_CRYPTO_AES_XTS_128	1
 
-/* Values for mktme_status (SW only construct) */
-#define MKTME_ENABLED			0
-#define MKTME_DISABLED			1
-#define MKTME_UNINITIALIZED		2
-static int mktme_status = MKTME_UNINITIALIZED;
-
 static int detect_tme(struct cpuinfo_x86 *c)
 {
-	u64 tme_activate, tme_policy, tme_crypto_algs;
-	int keyid_bits = 0, nr_keyids = 0;
-	static u64 tme_activate_cpu0 = 0;
+	int keyid_bits, nr_keyids;
+	u64 tme_activate;
 
 	rdmsrl(MSR_IA32_TME_ACTIVATE, tme_activate);
 
-	if (mktme_status != MKTME_UNINITIALIZED) {
-		if (tme_activate != tme_activate_cpu0) {
-			/* Broken BIOS? */
-			pr_err_once("x86/tme: configuration is inconsistent between CPUs\n");
-			pr_err_once("x86/tme: MKTME is not usable\n");
-			mktme_status = MKTME_DISABLED;
-
-			/* Proceed. We may need to exclude bits from x86_phys_bits. */
-		}
-	} else {
-		tme_activate_cpu0 = tme_activate;
-	}
-
 	if (!TME_ACTIVATE_LOCKED(tme_activate) || !TME_ACTIVATE_ENABLED(tme_activate)) {
 		pr_info_once("x86/tme: not enabled by BIOS\n");
-		mktme_status = MKTME_DISABLED;
 		return 0;
 	}
 
-	if (mktme_status != MKTME_UNINITIALIZED)
-		goto detect_keyid_bits;
-
 	pr_info("x86/tme: enabled by BIOS\n");
 
-	tme_policy = TME_ACTIVATE_POLICY(tme_activate);
-	if (tme_policy != TME_ACTIVATE_POLICY_AES_XTS_128)
-		pr_warn("x86/tme: Unknown policy is active: %#llx\n", tme_policy);
-
-	tme_crypto_algs = TME_ACTIVATE_CRYPTO_ALGS(tme_activate);
-	if (!(tme_crypto_algs & TME_ACTIVATE_CRYPTO_AES_XTS_128)) {
-		pr_err("x86/mktme: No known encryption algorithm is supported: %#llx\n",
-				tme_crypto_algs);
-		mktme_status = MKTME_DISABLED;
-	}
-detect_keyid_bits:
 	keyid_bits = TME_ACTIVATE_KEYID_BITS(tme_activate);
 	nr_keyids = (1UL << keyid_bits) - 1;
 	if (nr_keyids) {
@@ -387,11 +352,6 @@ static int detect_tme(struct cpuinfo_x86 *c)
 		pr_info_once("x86/mktme: disabled by BIOS\n");
 	}
 
-	if (mktme_status == MKTME_UNINITIALIZED) {
-		/* MKTME is usable */
-		mktme_status = MKTME_ENABLED;
-	}
-
 	return keyid_bits;
 }
 
-- 
  Kiryl Shutsemau / Kirill A. Shutemov