riscv: Add pte bit to distinguish swap from invalid

[ti-analog-linux-kernel/dmurphy-analog.git] / arch / riscv / include / asm / pgtable-bits.h

diff --git a/arch/riscv/include/asm/pgtable-bits.h b/arch/riscv/include/asm/pgtable-bits.h
index 2fa2942be221e480088ab1a5681c9240ef3a1e23..470755cb75584ee6e6b8c607070b2e89669ce816 100644 (file)
--- a/arch/riscv/include/asm/pgtable-bits.h
+++ b/arch/riscv/include/asm/pgtable-bits.h
@@ -35,6 +35,12 @@
 #define _PAGE_SPECIAL   _PAGE_SOFT
 #define _PAGE_TABLE     _PAGE_PRESENT
 
+/*
+ * _PAGE_PROT_NONE is set on not-present pages (and ignored by the hardware) to
+ * distinguish them from swapped out pages
+ */
+#define _PAGE_PROT_NONE _PAGE_READ
+
 #define _PAGE_PFN_SHIFT 10
 
 /* Set of bits to preserve across pte_modify() */