tree 0c606e5587a6c6a59b10d297e19ef9f5ca48f6a8
parent 4a3ecf201a1a49a804e8506df5906e446707c3b1
author Cao jin <caoj.fnst@cn.fujitsu.com> 1478094287 +0800
committer Michael Tokarev <mjt@tls.msk.ru> 1485289613 +0300

util/mmap-alloc: refactor a little bit for readability

1st mmap returns *ptr* which aligns to host page size,

    |             size + align               |
    ------------------------------------------
 ptr

input param *align* could be 1M, or 2M, or host page size. After
QEMU_ALIGN_UP, offset will >= 0

2nd mmap use flag MAP_FIXED, then it return ptr+offset, or else fail.
If it success, then we will have something like:

    | offset |          size             |
    --------------------------------------
 ptr      ptr1

*ptr1* is what we really want to return, it equals ptr+offset.

Signed-off-by: Cao jin <caoj.fnst@cn.fujitsu.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>