Re: [PATCH v1 1/3] arm64: mm: Fix rodata=full block mapping support for realm guests

[...]

diff --git a/arch/arm64/mm/init.c b/arch/arm64/mm/init.c
index 96711b8578fd0..b9b248d24fd10 100644
--- a/arch/arm64/mm/init.c
+++ b/arch/arm64/mm/init.c

@@ -350,7 +350,6 @@ void __init arch_mm_preinit(void)
 	}
 
 	swiotlb_init(swiotlb, flags);
-	swiotlb_update_mem_attributes();
 
 	/*
 	 * Check boundaries twice: Some fundamental inconsistencies can be

@@ -377,6 +376,14 @@ void __init arch_mm_preinit(void)
 	}
 }
 
+bool page_alloc_available __ro_after_init;
+
+void __init mem_init(void)
+{
+	page_alloc_available = true;
+	swiotlb_update_mem_attributes();

+}
+
 void free_initmem(void)
 {
 	void *lm_init_begin = lm_alias(__init_begin);

diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
index a6a00accf4f93..5b6a8d53e64b7 100644
--- a/arch/arm64/mm/mmu.c
+++ b/arch/arm64/mm/mmu.c

@@ -773,14 +773,33 @@ int split_kernel_leaf_mapping(unsigned long start, unsigned long end)
 {
 	int ret;
 
-	/*
-	 * !BBML2_NOABORT systems should not be trying to change permissions on
-	 * anything that is not pte-mapped in the first place. Just return early
-	 * and let the permission change code raise a warning if not already
-	 * pte-mapped.
-	 */
-	if (!system_supports_bbml2_noabort())
-		return 0;
+	if (!system_supports_bbml2_noabort()) {
+		/*
+		 * !BBML2_NOABORT systems should not be trying to change
+		 * permissions on anything that is not pte-mapped in the first
+		 * place. Just return early and let the permission change code
+		 * raise a warning if not already pte-mapped.
+		 */
+		if (system_capabilities_finalized() ||
+		    !cpu_supports_bbml2_noabort())
+			return 0;
+
+		/*
+		 * Boot-time: split_kernel_leaf_mapping_locked() allocates from
+		 * page allocator. Can't split until it's available.
+		 */
+		extern bool page_alloc_available;