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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/tlb.h | |
parent | 5a216a20837c5f5fa1ca4b8ae8991ffd96b08e6f (diff) | |
download | linux-stable-6252d702c5311ce916caf75ed82e5c8245171c92.tar.gz linux-stable-6252d702c5311ce916caf75ed82e5c8245171c92.tar.bz2 linux-stable-6252d702c5311ce916caf75ed82e5c8245171c92.zip |
[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/tlb.h')
-rw-r--r-- | include/asm-s390/tlb.h | 10 |
1 files changed, 10 insertions, 0 deletions
diff --git a/include/asm-s390/tlb.h b/include/asm-s390/tlb.h index 9b2ddb7aac49..3d8a96d39d9d 100644 --- a/include/asm-s390/tlb.h +++ b/include/asm-s390/tlb.h @@ -109,10 +109,15 @@ static inline void pte_free_tlb(struct mmu_gather *tlb, pgtable_t pte) /* * pmd_free_tlb frees a pmd table and clears the CRSTE for the * segment table entry from the tlb. + * If the mm uses a two level page table the single pmd is freed + * as the pgd. pmd_free_tlb checks the asce_limit against 2GB + * to avoid the double free of the pmd in this case. */ static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd) { #ifdef __s390x__ + if (tlb->mm->context.asce_limit <= (1UL << 31)) + return; if (!tlb->fullmm) { tlb->array[--tlb->nr_pxds] = pmd; if (tlb->nr_ptes >= tlb->nr_pxds) @@ -125,10 +130,15 @@ static inline void pmd_free_tlb(struct mmu_gather *tlb, pmd_t *pmd) /* * pud_free_tlb frees a pud table and clears the CRSTE for the * region third table entry from the tlb. + * If the mm uses a three level page table the single pud is freed + * as the pgd. pud_free_tlb checks the asce_limit against 4TB + * to avoid the double free of the pud in this case. */ static inline void pud_free_tlb(struct mmu_gather *tlb, pud_t *pud) { #ifdef __s390x__ + if (tlb->mm->context.asce_limit <= (1UL << 42)) + return; if (!tlb->fullmm) { tlb->array[--tlb->nr_pxds] = pud; if (tlb->nr_ptes >= tlb->nr_pxds) |