kexec: improve the readability of crash_shrink_memory()

The major adjustments are:
1. end = start + new_size.
   The 'end' here is not an accurate representation, because it is not the
   new end of crashk_res, but the start of ram_res, difference 1. So
   eliminate it and replace it with ram_res->start.
2. Use 'ram_res->start' and 'ram_res->end' as arguments to
   crash_free_reserved_phys_range() to indicate that the memory covered by
   'ram_res' is released from the crashk. And keep it close to
   insert_resource().
3. Replace 'if (start == end)' with 'if (!new_size)', clear indication that
   all crashk memory will be shrunken.

No functional change.

Link: https://lkml.kernel.org/r/[email protected]
Signed-off-by: Zhen Lei <[email protected]>
Acked-by: Baoquan He <[email protected]>
Cc: Cong Wang <[email protected]>
Cc: Eric W. Biederman <[email protected]>
Cc: Michael Holzheu <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

0 files changed, 0 insertions, 0 deletions