commit 56a159efebc0
Author: Christian Kujau <lists@nerdbynature.de>
Date:   Fri Feb 3 17:13:33 2023 +0100

    MTRR_TYPE_INVALID fixes as proposed by Linus.

diff --git a/arch/x86/include/asm/mtrr.h b/arch/x86/include/asm/mtrr.h
index f0eeaf6e5f5f..38ded2762847 100644
--- a/arch/x86/include/asm/mtrr.h
+++ b/arch/x86/include/asm/mtrr.h
@@ -53,7 +53,8 @@ static inline u8 mtrr_type_lookup(u64 addr, u64 end, u8 *uniform)
 	/*
 	 * Return no-MTRRs:
 	 */
-	return MTRR_TYPE_INVALID;
+	*uniform = 1;
+	return MTRR_TYPE_INVALID; /* ??? */
 }
 #define mtrr_save_fixed_ranges(arg) do {} while (0)
 #define mtrr_save_state() do {} while (0)
diff --git a/arch/x86/kernel/cpu/mtrr/generic.c b/arch/x86/kernel/cpu/mtrr/generic.c
index ee09d359e08f..0d77998b90ea 100644
--- a/arch/x86/kernel/cpu/mtrr/generic.c
+++ b/arch/x86/kernel/cpu/mtrr/generic.c
@@ -261,11 +261,13 @@ u8 mtrr_type_lookup(u64 start, u64 end, u8 *uniform)
 	/* Make end inclusive instead of exclusive */
 	end--;
 
+	type = MTRR_TYPE_INVALID; /* ??? */
 	if (!mtrr_state_set)
-		return MTRR_TYPE_INVALID;
+		goto out;
 
+	type = mtrr_state.def_type;
 	if (!(mtrr_state.enabled & MTRR_STATE_MTRR_ENABLED))
-		return MTRR_TYPE_INVALID;
+		goto out;
 
 	/*
 	 * Look up the fixed ranges first, which take priority over