From 76bfb994a7bd990d7ecbd710e7becd3d8d9a1910 Mon Sep 17 00:00:00 2001
From: p-szafonimateusz <p-szafonimateusz@xiaomi.com>
Date: Tue, 20 Aug 2024 13:18:17 +0200
Subject: [PATCH] arch/x86_64/src/intel64: use legacy method to map memory <4GB

the new mapping method may not work when we have to map memory at the early boot stage

Signed-off-by: p-szafonimateusz <p-szafonimateusz@xiaomi.com>
---
 arch/x86_64/src/intel64/intel64_map_region.c | 30 +++++++++++++++-----
 1 file changed, 23 insertions(+), 7 deletions(-)

diff --git a/arch/x86_64/src/intel64/intel64_map_region.c b/arch/x86_64/src/intel64/intel64_map_region.c
index 40f35622d65..9bf93cb1870 100644
--- a/arch/x86_64/src/intel64/intel64_map_region.c
+++ b/arch/x86_64/src/intel64/intel64_map_region.c
@@ -33,19 +33,19 @@
 #include "pgalloc.h"
 
 /****************************************************************************
- * Public Functions
+ * Private Functions
  ****************************************************************************/
 
 /****************************************************************************
- * Name: up_map_region
+ * Name: up_map_region_higmem
  *
  * Description:
- *   Map a memory region as 1:1 by MMU
+ *   Map a memory region as 1:1 by MMU for high memory region (>4Gb)
  *
  ****************************************************************************/
 
 #ifdef CONFIG_MM_PGALLOC
-int up_map_region(void *base, size_t size, int flags)
+static int up_map_region_highmem(void *base, size_t size, int flags)
 {
   uintptr_t bb;
   int       ptlevel;
@@ -113,7 +113,20 @@ int up_map_region(void *base, size_t size, int flags)
 
   return 0;
 }
-#else
+#endif
+
+/****************************************************************************
+ * Public Functions
+ ****************************************************************************/
+
+/****************************************************************************
+ * Name: up_map_region
+ *
+ * Description:
+ *   Map a memory region as 1:1 by MMU
+ *
+ ****************************************************************************/
+
 int up_map_region(void *base, size_t size, int flags)
 {
   uint64_t bb;
@@ -133,9 +146,13 @@ int up_map_region(void *base, size_t size, int flags)
 
   if (bb > 0xffffffff)
     {
-      /* More than 4GB can't be mapped with this implementtion */
+#ifdef CONFIG_MM_PGALLOC
+      return up_map_region_highmem(base, size, flags);
+#else
+      /* More than 4GB can't be mapped without CONFIG_MM_PGALLOC */
 
       PANIC();
+#endif
     }
 
   curr = bb;
@@ -149,4 +166,3 @@ int up_map_region(void *base, size_t size, int flags)
 
   return 0;
 }
-#endif