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authorMartin Schwidefsky <schwidefsky@de.ibm.com>2013-07-23 20:57:57 +0200
committerMartin Schwidefsky <schwidefsky@de.ibm.com>2013-08-22 12:20:06 +0200
commite509861105a3c1425f3f929bd631f88340b499bf (patch)
tree0616b1c17c1f88dfb63a3bce0774a3e518f49119 /arch/s390/mm/hugetlbpage.c
parent416fd0ffb14afead5b1feea14bbf33c2277942ef (diff)
downloadop-kernel-dev-e509861105a3c1425f3f929bd631f88340b499bf.zip
op-kernel-dev-e509861105a3c1425f3f929bd631f88340b499bf.tar.gz
s390/mm: cleanup page table definitions
Improve the encoding of the different pte types and the naming of the page, segment table and region table bits. Due to the different pte encoding the hugetlbfs primitives need to be adapted as well. To improve compatability with common code make the huge ptes use the encoding of normal ptes. The conversion between the pte and pmd encoding for a huge pte is done with set_huge_pte_at and huge_ptep_get. Overall the code is now easier to understand. Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'arch/s390/mm/hugetlbpage.c')
-rw-r--r--arch/s390/mm/hugetlbpage.c104
1 files changed, 95 insertions, 9 deletions
diff --git a/arch/s390/mm/hugetlbpage.c b/arch/s390/mm/hugetlbpage.c
index 121089d..b0bd0ae 100644
--- a/arch/s390/mm/hugetlbpage.c
+++ b/arch/s390/mm/hugetlbpage.c
@@ -8,21 +8,107 @@
#include <linux/mm.h>
#include <linux/hugetlb.h>
+static inline pmd_t __pte_to_pmd(pte_t pte)
+{
+ int none, 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.....
+ * Huge ptes are dirty by definition, a clean pte is made dirty
+ * by the conversion.
+ */
+ if (pte_present(pte)) {
+ pmd_val(pmd) = pte_val(pte) & PAGE_MASK;
+ 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)
+ pmd_val(pmd) |= _SEGMENT_ENTRY_PROTECT;
+ } else
+ pmd_val(pmd) = _SEGMENT_ENTRY_INVALID;
+ return pmd;
+}
+
+static inline pte_t __pmd_to_pte(pmd_t pmd)
+{
+ pte_t pte;
+
+ /*
+ * 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
+ * Huge ptes are dirty by definition
+ */
+ if (pmd_present(pmd)) {
+ pte_val(pte) = _PAGE_PRESENT | _PAGE_LARGE | _PAGE_DIRTY |
+ (pmd_val(pmd) & PAGE_MASK);
+ if (pmd_val(pmd) & _SEGMENT_ENTRY_INVALID)
+ pte_val(pte) |= _PAGE_INVALID;
+ else {
+ if (pmd_val(pmd) & _SEGMENT_ENTRY_PROTECT)
+ pte_val(pte) |= _PAGE_PROTECT;
+ else
+ pte_val(pte) |= _PAGE_WRITE;
+ }
+ } else
+ pte_val(pte) = _PAGE_INVALID;
+ return pte;
+}
void set_huge_pte_at(struct mm_struct *mm, unsigned long addr,
- pte_t *pteptr, pte_t pteval)
+ pte_t *ptep, pte_t pte)
{
- pmd_t *pmdp = (pmd_t *) pteptr;
- unsigned long mask;
+ pmd_t pmd;
+ pmd = __pte_to_pmd(pte);
if (!MACHINE_HAS_HPAGE) {
- pteptr = (pte_t *) pte_page(pteval)[1].index;
- mask = pte_val(pteval) &
- (_SEGMENT_ENTRY_INV | _SEGMENT_ENTRY_RO);
- pte_val(pteval) = (_SEGMENT_ENTRY + __pa(pteptr)) | mask;
+ pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN;
+ pmd_val(pmd) |= pte_page(pte)[1].index;
+ } else
+ pmd_val(pmd) |= _SEGMENT_ENTRY_LARGE | _SEGMENT_ENTRY_CO;
+ *(pmd_t *) ptep = pmd;
+}
+
+pte_t huge_ptep_get(pte_t *ptep)
+{
+ unsigned long origin;
+ pmd_t pmd;
+
+ pmd = *(pmd_t *) ptep;
+ if (!MACHINE_HAS_HPAGE && pmd_present(pmd)) {
+ origin = pmd_val(pmd) & _SEGMENT_ENTRY_ORIGIN;
+ pmd_val(pmd) &= ~_SEGMENT_ENTRY_ORIGIN;
+ pmd_val(pmd) |= *(unsigned long *) origin;
}
+ return __pmd_to_pte(pmd);
+}
- pmd_val(*pmdp) = pte_val(pteval);
+pte_t huge_ptep_get_and_clear(struct mm_struct *mm,
+ unsigned long addr, pte_t *ptep)
+{
+ pmd_t *pmdp = (pmd_t *) ptep;
+ pte_t pte = huge_ptep_get(ptep);
+
+ if (MACHINE_HAS_IDTE)
+ __pmd_idte(addr, pmdp);
+ else
+ __pmd_csp(pmdp);
+ pmd_val(*pmdp) = _SEGMENT_ENTRY_EMPTY;
+ return pte;
}
int arch_prepare_hugepage(struct page *page)
@@ -58,7 +144,7 @@ void arch_release_hugepage(struct page *page)
ptep = (pte_t *) page[1].index;
if (!ptep)
return;
- clear_table((unsigned long *) ptep, _PAGE_TYPE_EMPTY,
+ clear_table((unsigned long *) ptep, _PAGE_INVALID,
PTRS_PER_PTE * sizeof(pte_t));
page_table_free(&init_mm, (unsigned long *) ptep);
page[1].index = 0;
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