pat_patch.diff

--- arch/x86/mm/pat/memtype_interval.c	2022-10-30 23:19:28.000000000 +0100
+++ arch/x86/mm/pat/memtype_interval.c	2022-11-03 20:49:00.370271855 +0100
@@ -33,6 +33,16 @@
  * memtype_lock protects the rbtree.
  */
 
+int skip_pat_enable = 0;
+
+static int __init skip_pat_check(char *str)
+{
+	skip_pat_enable = 1;
+	pr_info("Disabled PAT check type (experimental)\n");
+	return 0;
+}
+early_param("skippatcheck", skip_pat_check);
+
 static inline u64 interval_start(struct memtype *entry)
 {
 	return entry->start;
@@ -86,19 +96,22 @@
 	if (entry_match == NULL)
 		goto success;
 
-	if (entry_match->type != found_type && newtype == NULL)
-		goto failure;
-
-	dprintk("Overlap at 0x%Lx-0x%Lx\n", entry_match->start, entry_match->end);
-	found_type = entry_match->type;
-
-	entry_match = interval_iter_next(entry_match, start, end-1);
-	while (entry_match) {
-		if (entry_match->type != found_type)
+	if (!skip_pat_enable) {
+		if (entry_match->type != found_type && newtype == NULL)
 			goto failure;
 
+		dprintk("Overlap at 0x%Lx-0x%Lx\n", entry_match->start, entry_match->end);
+		found_type = entry_match->type;
+
 		entry_match = interval_iter_next(entry_match, start, end-1);
+		while (entry_match) {
+			if (entry_match->type != found_type)
+				goto failure;
+
+			entry_match = interval_iter_next(entry_match, start, end-1);
+		}
 	}
+
 success:
 	if (newtype)
 		*newtype = found_type;