arm64: add POIndex defines

The 3-bit POIndex is stored in the PTE at bits 60..62.

Signed-off-by: Joey Gouly <[email protected]>
Cc: Catalin Marinas <[email protected]>
Cc: Will Deacon <[email protected]>
Acked-by: Catalin Marinas <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Will Deacon <[email protected]>

Author: jgouly

arch/arm64/include/asm/pgtable-hwdef.h

@@ -199,6 +199,16 @@
 #define PTE_PI_IDX_2	53	/* PXN */
 #define PTE_PI_IDX_3	54	/* UXN */
 
+/*
+ * POIndex[2:0] encoding (Permission Overlay Extension)
+ */
+#define PTE_PO_IDX_0	(_AT(pteval_t, 1) << 60)
+#define PTE_PO_IDX_1	(_AT(pteval_t, 1) << 61)
+#define PTE_PO_IDX_2	(_AT(pteval_t, 1) << 62)
+
+#define PTE_PO_IDX_MASK		GENMASK_ULL(62, 60)
+
+
 /*
  * Memory Attribute override for Stage-2 (MemAttr[3:0])
  */