Add implementation for the unsafe functions __set_direct_map*(). They do
not verify for can_set_direct_map() and expect the caller to do so
beforehand.

Signed-off-by: Vincent Donnefort <vdonnefort@google.com>

diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h
index 1a37f4ef130b..080a40846bbe 100644
--- a/arch/arm64/include/asm/set_memory.h
+++ b/arch/arm64/include/asm/set_memory.h
@@ -16,6 +16,10 @@ int set_memory_valid(unsigned long addr, int numpages, int enable);
 
 int set_direct_map_invalid_noflush(struct page *page);
 int set_direct_map_default_noflush(struct page *page);
+int __set_direct_map_invalid_noflush(struct page *page);
+#define __set_direct_map_invalid_noflush __set_direct_map_invalid_noflush
+int __set_direct_map_default_noflush(struct page *page);
+#define __set_direct_map_default_noflush __set_direct_map_default_noflush
 int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid);
 bool kernel_page_present(struct page *page);
 
diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c
index c59ef17eb0d0..28adab0edace 100644
--- a/arch/arm64/mm/pageattr.c
+++ b/arch/arm64/mm/pageattr.c
@@ -294,28 +294,38 @@ int set_memory_valid(unsigned long addr, int numpages, int enable)
 					__pgprot(PTE_PRESENT_VALID_KERNEL));
 }
 
-int set_direct_map_invalid_noflush(struct page *page)
+int __set_direct_map_invalid_noflush(struct page *page)
 {
 	pgprot_t clear_mask = __pgprot(PTE_PRESENT_VALID_KERNEL);
 	pgprot_t set_mask = __pgprot(PTE_PRESENT_INVALID);
 
+	return update_range_prot((unsigned long)page_address(page),
+				 PAGE_SIZE, set_mask, clear_mask);
+}
+
+int set_direct_map_invalid_noflush(struct page *page)
+{
 	if (!can_set_direct_map())
 		return 0;
 
+	return __set_direct_map_invalid_noflush(page);
+}
+
+int __set_direct_map_default_noflush(struct page *page)
+{
+	pgprot_t set_mask = __pgprot(PTE_PRESENT_VALID_KERNEL | PTE_WRITE);
+	pgprot_t clear_mask = __pgprot(PTE_PRESENT_INVALID | PTE_RDONLY);
+
 	return update_range_prot((unsigned long)page_address(page),
 				 PAGE_SIZE, set_mask, clear_mask);
 }
 
 int set_direct_map_default_noflush(struct page *page)
 {
-	pgprot_t set_mask = __pgprot(PTE_PRESENT_VALID_KERNEL | PTE_WRITE);
-	pgprot_t clear_mask = __pgprot(PTE_PRESENT_INVALID | PTE_RDONLY);
-
 	if (!can_set_direct_map())
 		return 0;
 
-	return update_range_prot((unsigned long)page_address(page),
-				 PAGE_SIZE, set_mask, clear_mask);
+	return __set_direct_map_default_noflush(page);
 }
 
 static int __set_memory_enc_dec(unsigned long addr,
-- 
2.55.0.970.g62bdec98f9-goog