[PATCH v6 12/30] set_memory: Introduce arch_has_pte_only_direct_map()

[Kevin Brodsky <kevin.brodsky@arm.com>]

Introduce a helper that returns whether the linear map is fully
PTE-mapped (i.e. no block mapping is used). This is a runtime
decision for some architectures, hence the need for a new arch
helper.

Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
---
 include/linux/set_memory.h | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/include/linux/set_memory.h b/include/linux/set_memory.h
index 7b3a8bfde3c6..c6df55422da2 100644
--- a/include/linux/set_memory.h
+++ b/include/linux/set_memory.h
@@ -58,6 +58,19 @@ static inline bool can_set_direct_map(void)
 #endif
 #endif /* CONFIG_ARCH_HAS_SET_DIRECT_MAP */
 
+#ifndef arch_has_pte_only_direct_map
+/*
+ * The default assumption is that the direct map might be created using block
+ * mappings (PMD or higher). An architecture may override this if the direct
+ * map is fully PTE-mapped.
+ */
+static inline bool arch_has_pte_only_direct_map(void)
+{
+	return false;
+}
+#define arch_has_pte_only_direct_map arch_has_pte_only_direct_map
+#endif
+
 #ifdef CONFIG_X86_64
 int set_mce_nospec(unsigned long pfn);
 int clear_mce_nospec(unsigned long pfn);
-- 
2.51.2