-static inline void switch_mm(struct mm_struct *prev, struct mm_struct *next,
- struct task_struct *tsk)
+#ifdef CONFIG_MPU
+static inline void protect_page(struct mm_struct *mm, unsigned long addr,
+ unsigned long flags)
+{
+ unsigned long *mask = mm->context.page_rwx_mask;
+ unsigned long page = addr >> 12;
+ unsigned long idx = page >> 5;
+ unsigned long bit = 1 << (page & 31);
+
+ if (flags & VM_MAYREAD)
+ mask[idx] |= bit;
+ else
+ mask[idx] &= ~bit;
+ mask += page_mask_nelts;
+ if (flags & VM_MAYWRITE)
+ mask[idx] |= bit;
+ else
+ mask[idx] &= ~bit;
+ mask += page_mask_nelts;
+ if (flags & VM_MAYEXEC)
+ mask[idx] |= bit;
+ else
+ mask[idx] &= ~bit;
+}
+
+static inline void update_protections(struct mm_struct *mm)