hw/hyperv/hv-balloon-internal.h

   1 /*
   2  * QEMU Hyper-V Dynamic Memory Protocol driver
   3  *
   4  * Copyright (C) 2020-2023 Oracle and/or its affiliates.
   5  *
   6  * This work is licensed under the terms of the GNU GPL, version 2 or later.
   7  * See the COPYING file in the top-level directory.
   8  */
   9
  10 #ifndef HW_HYPERV_HV_BALLOON_INTERNAL_H
  11 #define HW_HYPERV_HV_BALLOON_INTERNAL_H
  12
  13 #include "qemu/osdep.h"
  14
  15 #define HV_BALLOON_PFN_SHIFT 12
  16 #define HV_BALLOON_PAGE_SIZE (1 << HV_BALLOON_PFN_SHIFT)
  17
  18 #define SUM_OVERFLOW_U64(in1, in2) ((in1) > UINT64_MAX - (in2))
  19 #define SUM_SATURATE_U64(in1, in2)              \
  20     ({                                          \
  21         uint64_t _in1 = (in1), _in2 = (in2);    \
  22         uint64_t _result;                       \
  23                                                 \
  24         if (!SUM_OVERFLOW_U64(_in1, _in2)) {    \
  25             _result = _in1 + _in2;              \
  26         } else {                                \
  27             _result = UINT64_MAX;               \
  28         }                                       \
  29                                                 \
  30         _result;                                \
  31     })
  32
  33 #endif