diff options
Diffstat (limited to 'include/linux')
| -rw-r--r-- | include/linux/mm.h | 41 |
1 files changed, 41 insertions, 0 deletions
diff --git a/include/linux/mm.h b/include/linux/mm.h index 2d060081caa5..5c887c4ea29e 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -2962,6 +2962,7 @@ static inline pmd_t *pmd_alloc(struct mm_struct *mm, pud_t *pud, unsigned long a #endif /* CONFIG_MMU */ enum pt_flags { + PT_kernel = PG_referenced, PT_reserved = PG_reserved, /* High bits are used for zone/node/section */ }; @@ -2988,6 +2989,46 @@ static inline bool pagetable_is_reserved(struct ptdesc *pt) } /** + * ptdesc_set_kernel - Mark a ptdesc used to map the kernel + * @ptdesc: The ptdesc to be marked + * + * Kernel page tables often need special handling. Set a flag so that + * the handling code knows this ptdesc will not be used for userspace. + */ +static inline void ptdesc_set_kernel(struct ptdesc *ptdesc) +{ + set_bit(PT_kernel, &ptdesc->pt_flags.f); +} + +/** + * ptdesc_clear_kernel - Mark a ptdesc as no longer used to map the kernel + * @ptdesc: The ptdesc to be unmarked + * + * Use when the ptdesc is no longer used to map the kernel and no longer + * needs special handling. + */ +static inline void ptdesc_clear_kernel(struct ptdesc *ptdesc) +{ + /* + * Note: the 'PG_referenced' bit does not strictly need to be + * cleared before freeing the page. But this is nice for + * symmetry. + */ + clear_bit(PT_kernel, &ptdesc->pt_flags.f); +} + +/** + * ptdesc_test_kernel - Check if a ptdesc is used to map the kernel + * @ptdesc: The ptdesc being tested + * + * Call to tell if the ptdesc used to map the kernel. + */ +static inline bool ptdesc_test_kernel(const struct ptdesc *ptdesc) +{ + return test_bit(PT_kernel, &ptdesc->pt_flags.f); +} + +/** * pagetable_alloc - Allocate pagetables * @gfp: GFP flags * @order: desired pagetable order |