[PATCH v8 06/15] mm: add hw_pte_val for HW PTE storage

[Alexander Gordeev]

From: Muhammad Usama Anjum <usama.anjum@xxxxxxx>

Atomic PTE updates need an lvalue for the bits stored in an HW PTE.
pte_val() only accepts a SW PTE value, so it cannot operate directly on
a distinct hw_pte_t.

Add hw_pte_val() to expose the underlying pte_val() lvalue. Access the
wrapper's __pte member when hw_pte_t is distinct, and use pte_val()
directly when it remains an alias of pte_t.

Signed-off-by: Muhammad Usama Anjum <usama.anjum@xxxxxxx>
---
 include/linux/pgtable_types.h | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/include/linux/pgtable_types.h b/include/linux/pgtable_types.h
index d6c5a7548550..ee4eace5c3e1 100644
--- a/include/linux/pgtable_types.h
+++ b/include/linux/pgtable_types.h
@@ -9,9 +9,13 @@
 #ifdef CONFIG_ARCH_HAS_HW_PTE_T
 typedef struct __hw_pte_t { pte_t __pte; } hw_pte_t;
 #define __pte_from_hw(pte)	((pte).__pte)
+
+#define hw_pte_val(x)  pte_val((x).__pte)
 #else
 #define hw_pte_t pte_t
 #define __pte_from_hw(pte)	(pte)
+
+#define hw_pte_val(x)  pte_val(x)
 #endif
 
 #endif /* !__ASSEMBLY__ */
-- 
2.53.0