s390/mm: implement software referenced bits

[deliverable/linux.git] / arch / s390 / mm / hugetlbpage.c

diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index b0bd0ae17796fe6d0620f24c74d1c4c66d5a27b3..248445f92604efff09a5188352c3e6fba1248bb0 100644 (file)
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -10,19 +10,25 @@
 
 static inline pmd_t __pte_to_pmd(pte_t pte)
 {
-       int none, prot;
+       int none, young, prot;
        pmd_t pmd;
 
        /*
-        * Convert encoding       pte bits        pmd bits
-        *                      .IR.....wdtp    ..R...I.....
-        * empty                .10.....0000 -> ..0...1.....
-        * prot-none, clean     .11.....0001 -> ..1...1.....
-        * prot-none, dirty     .10.....0101 -> ..1...1.....
-        * read-only, clean     .01.....0001 -> ..1...0.....
-        * read-only, dirty     .01.....0101 -> ..1...0.....
-        * read-write, clean    .01.....1001 -> ..0...0.....
-        * read-write, dirty    .00.....1101 -> ..0...0.....
+        * Convert encoding               pte bits        pmd bits
+        *                              .IR...wrdytp    ..R...I...y.
+        * empty                        .10...000000 -> ..0...1...0.
+        * prot-none, clean, old        .11...000001 -> ..0...1...1.
+        * prot-none, clean, young      .11...000101 -> ..1...1...1.
+        * prot-none, dirty, old        .10...001001 -> ..0...1...1.
+        * prot-none, dirty, young      .10...001101 -> ..1...1...1.
+        * read-only, clean, old        .11...010001 -> ..1...1...0.
+        * read-only, clean, young      .01...010101 -> ..1...0...1.
+        * read-only, dirty, old        .11...011001 -> ..1...1...0.
+        * read-only, dirty, young      .01...011101 -> ..1...0...1.
+        * read-write, clean, old       .11...110001 -> ..0...1...0.
+        * read-write, clean, young     .01...110101 -> ..0...0...1.
+        * read-write, dirty, old       .10...111001 -> ..0...1...0.
+        * read-write, dirty, young     .00...111101 -> ..0...0...1.
         * Huge ptes are dirty by definition, a clean pte is made dirty
         * by the conversion.
         */
@@ -31,9 +37,14 @@ static inline pmd_t __pte_to_pmd(pte_t pte)
                if (pte_val(pte) & _PAGE_INVALID)
                        pmd_val(pmd) |= _SEGMENT_ENTRY_INVALID;
                none = (pte_val(pte) & _PAGE_PRESENT) &&
-                       (pte_val(pte) & _PAGE_INVALID);
-               prot = (pte_val(pte) & _PAGE_PROTECT);
-               if (prot || none)
+                       !(pte_val(pte) & _PAGE_READ) &&
+                       !(pte_val(pte) & _PAGE_WRITE);
+               prot = (pte_val(pte) & _PAGE_PROTECT) &&
+                       !(pte_val(pte) & _PAGE_WRITE);
+               young = pte_val(pte) & _PAGE_YOUNG;
+               if (none || young)
+                       pmd_val(pmd) |= _SEGMENT_ENTRY_YOUNG;
+               if (prot || (none && young))
                        pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
        } else
                pmd_val(pmd) = _SEGMENT_ENTRY_INVALID;
@@ -46,11 +57,14 @@ static inline pte_t __pmd_to_pte(pmd_t pmd)
 
        /*
         * Convert encoding       pmd bits        pte bits
-        *                      ..R...I.....    .IR.....wdtp
-        * empty                ..0...1..... -> .10.....0000
-        * prot-none, young     ..1...1..... -> .10.....0101
-        * read-only, young     ..1...0..... -> .01.....0101
-        * read-write, young    ..0...0..... -> .00.....1101
+        *                      ..R...I...y.    .IR...wrdytp
+        * empty                ..0...1...0. -> .10...000000
+        * prot-none, old       ..0...1...1. -> .10...001001
+        * prot-none, young     ..1...1...1. -> .10...001101
+        * read-only, old       ..1...1...0. -> .11...011001
+        * read-only, young     ..1...0...1. -> .01...011101
+        * read-write, old      ..0...1...0. -> .10...111001
+        * read-write, young    ..0...0...1. -> .00...111101
         * Huge ptes are dirty by definition
         */
        if (pmd_present(pmd)) {
@@ -58,11 +72,17 @@ static inline pte_t __pmd_to_pte(pmd_t pmd)
                        (pmd_val(pmd) & PAGE_MASK);
                if (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID)
                        pte_val(pte) |= _PAGE_INVALID;
-               else {
+               if (pmd_prot_none(pmd)) {
+                       if (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT)
+                               pte_val(pte) |= _PAGE_YOUNG;
+               } else {
+                       pte_val(pte) |= _PAGE_READ;
                        if (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT)
                                pte_val(pte) |= _PAGE_PROTECT;
                        else
                                pte_val(pte) |= _PAGE_WRITE;
+                       if (pmd_val(pmd) & _SEGMENT_ENTRY_YOUNG)
+                               pte_val(pte) |= _PAGE_YOUNG;
                }
        } else
                pte_val(pte) = _PAGE_INVALID;