extern void kvfree(const void *addr);
-static inline atomic_t *compound_mapcount_ptr(struct page *page)
-{
- return &page[1].compound_mapcount;
-}
-
static inline int compound_mapcount(struct page *page)
{
VM_BUG_ON_PAGE(!PageCompound(page), page);
#endif /* CONFIG_DEVICE_PRIVATE || CONFIG_DEVICE_PUBLIC */
+/* 127: arbitrary random number, small enough to assemble well */
+#define page_ref_zero_or_close_to_overflow(page) \
+ ((unsigned int) page_ref_count(page) + 127u <= 127u)
+
static inline void get_page(struct page *page)
{
page = compound_head(page);
* Getting a normal page or the head of a compound page
* requires to already have an elevated page->_refcount.
*/
- VM_BUG_ON_PAGE(page_ref_count(page) <= 0, page);
+ VM_BUG_ON_PAGE(page_ref_zero_or_close_to_overflow(page), page);
+ page_ref_inc(page);
+}
+
+static inline __must_check bool try_get_page(struct page *page)
+{
+ page = compound_head(page);
+ if (WARN_ON_ONCE(page_ref_count(page) <= 0))
+ return false;
page_ref_inc(page);
+ return true;
}
static inline void put_page(struct page *page)
static inline void mm_inc_nr_puds(struct mm_struct *mm)
{
+ if (mm_pud_folded(mm))
+ return;
atomic_long_add(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes);
}
static inline void mm_dec_nr_puds(struct mm_struct *mm)
{
+ if (mm_pud_folded(mm))
+ return;
atomic_long_sub(PTRS_PER_PUD * sizeof(pud_t), &mm->pgtables_bytes);
}
#endif
static inline void mm_inc_nr_pmds(struct mm_struct *mm)
{
+ if (mm_pmd_folded(mm))
+ return;
atomic_long_add(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes);
}
static inline void mm_dec_nr_pmds(struct mm_struct *mm)
{
+ if (mm_pmd_folded(mm))
+ return;
atomic_long_sub(PTRS_PER_PMD * sizeof(pmd_t), &mm->pgtables_bytes);
}
#endif
return vma;
}
+static inline bool range_in_vma(struct vm_area_struct *vma,
+ unsigned long start, unsigned long end)
+{
+ return (vma && vma->vm_start <= start && end <= vma->vm_end);
+}
+
#ifdef CONFIG_MMU
pgprot_t vm_get_page_prot(unsigned long vm_flags);
void vma_set_page_prot(struct vm_area_struct *vma);