diff options
Diffstat (limited to 'arch/s390/mm')
| -rw-r--r-- | arch/s390/mm/gup.c | 11 | ||||
| -rw-r--r-- | arch/s390/mm/pgtable.c | 18 |
2 files changed, 28 insertions, 1 deletions
diff --git a/arch/s390/mm/gup.c b/arch/s390/mm/gup.c index eeaf8023851f..60acb93a4680 100644 --- a/arch/s390/mm/gup.c +++ b/arch/s390/mm/gup.c @@ -115,7 +115,16 @@ static inline int gup_pmd_range(pud_t *pudp, pud_t pud, unsigned long addr, pmd = *pmdp; barrier(); next = pmd_addr_end(addr, end); - if (pmd_none(pmd)) + /* + * The pmd_trans_splitting() check below explains why + * pmdp_splitting_flush() has to serialize with + * smp_call_function() against our disabled IRQs, to stop + * this gup-fast code from running while we set the + * splitting bit in the pmd. Returning zero will take + * the slow path that will call wait_split_huge_page() + * if the pmd is still in splitting state. + */ + if (pmd_none(pmd) || pmd_trans_splitting(pmd)) return 0; if (unlikely(pmd_huge(pmd))) { if (!gup_huge_pmd(pmdp, pmd, addr, next, diff --git a/arch/s390/mm/pgtable.c b/arch/s390/mm/pgtable.c index b402991e43d7..a6131d1fe6c0 100644 --- a/arch/s390/mm/pgtable.c +++ b/arch/s390/mm/pgtable.c @@ -866,3 +866,21 @@ bool kernel_page_present(struct page *page) return cc == 0; } #endif /* CONFIG_HIBERNATION && CONFIG_DEBUG_PAGEALLOC */ + +#ifdef CONFIG_TRANSPARENT_HUGEPAGE +static void pmdp_splitting_flush_sync(void *arg) +{ + /* Simply deliver the interrupt */ +} + +void pmdp_splitting_flush(struct vm_area_struct *vma, unsigned long address, + pmd_t *pmdp) +{ + VM_BUG_ON(address & ~HPAGE_PMD_MASK); + if (!test_and_set_bit(_SEGMENT_ENTRY_SPLIT_BIT, + (unsigned long *) pmdp)) { + /* need to serialize against gup-fast (IRQ disabled) */ + smp_call_function(pmdp_splitting_flush_sync, NULL, 1); + } +} +#endif /* CONFIG_TRANSPARENT_HUGEPAGE */ |