1 files changed, 12 insertions, 1 deletions

diff --git a/arch/x86/mm/pat.c b/arch/x86/mm/pat.c
index b4663885308f..1cc1d37f1de7 100644
--- a/arch/x86/mm/pat.c
+++ b/arch/x86/mm/pat.c
@@ -40,11 +40,22 @@
 static bool boot_cpu_done;
 
 static int __read_mostly __pat_enabled = IS_ENABLED(CONFIG_X86_PAT);
+static void init_cache_modes(void);
 
-static inline void pat_disable(const char *reason)
+void pat_disable(const char *reason)
 {
+        if (!__pat_enabled)
+                return;
+
+        if (boot_cpu_done) {
+                WARN_ONCE(1, "x86/PAT: PAT cannot be disabled after initialization\n");
+                return;
+        }
+
         __pat_enabled = 0;
         pr_info("x86/PAT: %s\n", reason);
+
+        init_cache_modes();
 }
 
 static int __init nopat(char *str)