#ifndef __BACKPORT_MM_H
#define __BACKPORT_MM_H
#include_next <linux/mm.h>

#ifndef VM_NODUMP
/*
 * defined here to allow things to compile but technically
 * using this for memory regions will yield in a no-op on newer
 * kernels but on older kernels (v3.3 and older) this bit was used
 * for VM_ALWAYSDUMP. The goal was to remove this bit moving forward
 * and since we can't skip the core dump on old kernels we just make
 * this bit name now a no-op.
 *
 * For details see commits: 909af7 accb61fe cdaaa7003
 */
#define VM_NODUMP      0x0
#endif

#ifndef VM_DONTDUMP
#define VM_DONTDUMP    VM_NODUMP
#endif

#if (LINUX_VERSION_CODE < KERNEL_VERSION(3,8,0))
#define vm_iomap_memory LINUX_BACKPORT(vm_iomap_memory)
int vm_iomap_memory(struct vm_area_struct *vma, phys_addr_t start, unsigned long len);
#endif

#if LINUX_VERSION_CODE < KERNEL_VERSION(3,15,0)
#define kvfree LINUX_BACKPORT(kvfree)
void kvfree(const void *addr);
#endif /* < 3.15 */

#if (LINUX_VERSION_CODE < KERNEL_VERSION(3,20,0))
#define get_user_pages_unlocked LINUX_BACKPORT(get_user_pages_unlocked)
static inline long
get_user_pages_unlocked(struct task_struct *tsk, struct mm_struct *mm,
			unsigned long start, unsigned long nr_pages,
			int write, int force, struct page **pages)
{
	long err;

	down_read(&mm->mmap_sem);
	err = get_user_pages(tsk, mm, start, nr_pages, write, force, pages,
			     NULL);
	up_read(&mm->mmap_sem);

	return err;
}
#endif
#endif /* __BACKPORT_MM_H */