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author | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-02-09 18:24:37 +0100 |
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committer | Martin Schwidefsky <schwidefsky@de.ibm.com> | 2008-02-09 18:24:41 +0100 |
commit | 6252d702c5311ce916caf75ed82e5c8245171c92 (patch) | |
tree | 3490f27b5f888ff2c1ec915d4e7201000f37a771 /include/asm-s390/pgtable.h | |
parent | 5a216a20837c5f5fa1ca4b8ae8991ffd96b08e6f (diff) | |
download | kernel_samsung_smdk4412-6252d702c5311ce916caf75ed82e5c8245171c92.zip kernel_samsung_smdk4412-6252d702c5311ce916caf75ed82e5c8245171c92.tar.gz kernel_samsung_smdk4412-6252d702c5311ce916caf75ed82e5c8245171c92.tar.bz2 |
[S390] dynamic page tables.
Add support for different number of page table levels dependent
on the highest address used for a process. This will cause a 31 bit
process to use a two level page table instead of the four level page
table that is the default after the pud has been introduced. Likewise
a normal 64 bit process will use three levels instead of four. Only
if a process runs out of the 4 tera bytes which can be addressed with
a three level page table the fourth level is dynamically added. Then
the process can use up to 8 peta byte.
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Diffstat (limited to 'include/asm-s390/pgtable.h')
-rw-r--r-- | include/asm-s390/pgtable.h | 38 |
1 files changed, 31 insertions, 7 deletions
diff --git a/include/asm-s390/pgtable.h b/include/asm-s390/pgtable.h index 8f473a7..65154dc 100644 --- a/include/asm-s390/pgtable.h +++ b/include/asm-s390/pgtable.h @@ -421,36 +421,54 @@ static inline int pud_bad(pud_t pud) { return 0; } static inline int pgd_present(pgd_t pgd) { + if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2) + return 1; return (pgd_val(pgd) & _REGION_ENTRY_ORIGIN) != 0UL; } static inline int pgd_none(pgd_t pgd) { + if ((pgd_val(pgd) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R2) + return 0; return (pgd_val(pgd) & _REGION_ENTRY_INV) != 0UL; } static inline int pgd_bad(pgd_t pgd) { + /* + * With dynamic page table levels the pgd can be a region table + * entry or a segment table entry. Check for the bit that are + * invalid for either table entry. + */ unsigned long mask = - ~_REGION_ENTRY_ORIGIN & ~_REGION_ENTRY_INV & + ~_SEGMENT_ENTRY_ORIGIN & ~_REGION_ENTRY_INV & ~_REGION_ENTRY_TYPE_MASK & ~_REGION_ENTRY_LENGTH; return (pgd_val(pgd) & mask) != 0; } static inline int pud_present(pud_t pud) { + if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3) + return 1; return (pud_val(pud) & _REGION_ENTRY_ORIGIN) != 0UL; } static inline int pud_none(pud_t pud) { + if ((pud_val(pud) & _REGION_ENTRY_TYPE_MASK) < _REGION_ENTRY_TYPE_R3) + return 0; return (pud_val(pud) & _REGION_ENTRY_INV) != 0UL; } static inline int pud_bad(pud_t pud) { + /* + * With dynamic page table levels the pud can be a region table + * entry or a segment table entry. Check for the bit that are + * invalid for either table entry. + */ unsigned long mask = - ~_REGION_ENTRY_ORIGIN & ~_REGION_ENTRY_INV & + ~_SEGMENT_ENTRY_ORIGIN & ~_REGION_ENTRY_INV & ~_REGION_ENTRY_TYPE_MASK & ~_REGION_ENTRY_LENGTH; return (pud_val(pud) & mask) != 0; } @@ -535,7 +553,8 @@ static inline int pte_young(pte_t pte) static inline void pgd_clear_kernel(pgd_t * pgd) { - pgd_val(*pgd) = _REGION2_ENTRY_EMPTY; + if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2) + pgd_val(*pgd) = _REGION2_ENTRY_EMPTY; } static inline void pgd_clear(pgd_t * pgd) @@ -549,10 +568,11 @@ static inline void pgd_clear(pgd_t * pgd) static inline void pud_clear_kernel(pud_t *pud) { - pud_val(*pud) = _REGION3_ENTRY_EMPTY; + if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) + pud_val(*pud) = _REGION3_ENTRY_EMPTY; } -static inline void pud_clear(pud_t * pud) +static inline void pud_clear(pud_t *pud) { pud_t *shadow = get_shadow_table(pud); @@ -841,13 +861,17 @@ static inline pte_t mk_pte(struct page *page, pgprot_t pgprot) static inline pud_t *pud_offset(pgd_t *pgd, unsigned long address) { - pud_t *pud = (pud_t *) pgd_deref(*pgd); + pud_t *pud = (pud_t *) pgd; + if ((pgd_val(*pgd) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R2) + pud = (pud_t *) pgd_deref(*pgd); return pud + pud_index(address); } static inline pmd_t *pmd_offset(pud_t *pud, unsigned long address) { - pmd_t *pmd = (pmd_t *) pud_deref(*pud); + pmd_t *pmd = (pmd_t *) pud; + if ((pud_val(*pud) & _REGION_ENTRY_TYPE_MASK) == _REGION_ENTRY_TYPE_R3) + pmd = (pmd_t *) pud_deref(*pud); return pmd + pmd_index(address); } |