+ member of the stat structure)
+
+SNAPSHOT_SET_SWAP_AREA - set the resume partition and the offset (in <PAGE_SIZE>
+ units) from the beginning of the partition at which the swap header is
+ located (the last ioctl() argument should point to a struct
+ resume_swap_area, as defined in kernel/power/power.h, containing the
+ resume device specification, as for the SNAPSHOT_SET_SWAP_FILE ioctl(),
+ and the offset); for swap partitions the offset is always 0, but it is
+ different to zero for swap files (please see
+ Documentation/swsusp-and-swap-files.txt for details).
+ The SNAPSHOT_SET_SWAP_AREA ioctl() is considered as a replacement for
+ SNAPSHOT_SET_SWAP_FILE which is regarded as obsolete. It is
+ recommended to always use this call, because the code to set the resume
+ partition may be removed from future kernels
+
+SNAPSHOT_S2RAM - suspend to RAM; using this call causes the kernel to
+ immediately enter the suspend-to-RAM state, so this call must always
+ be preceded by the SNAPSHOT_FREEZE call and it is also necessary
+ to use the SNAPSHOT_UNFREEZE call after the system wakes up. This call
+ is needed to implement the suspend-to-both mechanism in which the
+ suspend image is first created, as though the system had been suspended
+ to disk, and then the system is suspended to RAM (this makes it possible
+ to resume the system from RAM if there's enough battery power or restore
+ its state on the basis of the saved suspend image otherwise)
+
+SNAPSHOT_PMOPS - enable the usage of the pmops->prepare, pmops->enter and
+ pmops->finish methods (the in-kernel swsusp knows these as the "platform
+ method") which are needed on many machines to (among others) speed up
+ the resume by letting the BIOS skip some steps or to let the system
+ recognise the correct state of the hardware after the resume (in
+ particular on many machines this ensures that unplugged AC
+ adapters get correctly detected and that kacpid does not run wild after
+ the resume). The last ioctl() argument can take one of the three
+ values, defined in kernel/power/power.h:
+ PMOPS_PREPARE - make the kernel carry out the
+ pm_ops->prepare(PM_SUSPEND_DISK) operation
+ PMOPS_ENTER - make the kernel power off the system by calling
+ pm_ops->enter(PM_SUSPEND_DISK)
+ PMOPS_FINISH - make the kernel carry out the
+ pm_ops->finish(PM_SUSPEND_DISK) operation