/////////////////////////////////////////////////////////////////////////
// $Id: flag_ctrl_pro.cc 12407 2014-07-08 19:15:54Z sshwarts $
/////////////////////////////////////////////////////////////////////////
//
//  Copyright (C) 2001-2011  The Bochs Project
//
//  This library is free software; you can redistribute it and/or
//  modify it under the terms of the GNU Lesser General Public
//  License as published by the Free Software Foundation; either
//  version 2 of the License, or (at your option) any later version.
//
//  This library is distributed in the hope that it will be useful,
//  but WITHOUT ANY WARRANTY; without even the implied warranty of
//  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
//  Lesser General Public License for more details.
//
//  You should have received a copy of the GNU Lesser General Public
//  License along with this library; if not, write to the Free Software
//  Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA B 02110-1301 USA
//
/////////////////////////////////////////////////////////////////////////

#define NEED_CPU_REG_SHORTCUTS 1
#include "bochs.h"
#include "cpu.h"
#define LOG_THIS BX_CPU_THIS_PTR

void BX_CPP_AttrRegparmN(1) BX_CPU_C::setEFlags(Bit32u new_eflags)
{
  Bit32u eflags = BX_CPU_THIS_PTR eflags;

  // VM flag could not be set from long mode
#if BX_SUPPORT_X86_64
  if (long_mode()) {
    if (BX_CPU_THIS_PTR get_VM()) BX_PANIC(("VM is set in long mode !"));
    new_eflags &= ~EFlagsVMMask;
  }
#endif

  BX_CPU_THIS_PTR eflags = new_eflags;
  setEFlagsOSZAPC(new_eflags);			// update lazy flags state

  if (BX_CPU_THIS_PTR get_RF()) invalidate_prefetch_q();

  if (BX_CPU_THIS_PTR get_TF()) {
    BX_CPU_THIS_PTR async_event = 1; // TF == 1
  }

  if ((eflags ^ new_eflags) & EFlagsIFMask) {
    handleInterruptMaskChange();
  }

#if BX_CPU_LEVEL >= 4
  handleAlignmentCheck(/* EFLAGS.AC reloaded */);
#endif

  if ((eflags ^ new_eflags) & EFlagsVMMask) {
    handleCpuModeChange(); // VM flag was changed
  }
}

  void BX_CPP_AttrRegparmN(2)
BX_CPU_C::writeEFlags(Bit32u flags, Bit32u changeMask)
{
  // Build a mask of the non-reserved bits:
  // ID,VIP,VIF,AC,VM,RF,x,NT,IOPL,OF,DF,IF,TF,SF,ZF,x,AF,x,PF,x,CF
  Bit32u supportMask = 0x00037fd5;
#if BX_CPU_LEVEL >= 4
  supportMask |= (EFlagsIDMask | EFlagsACMask); // ID/AC
#endif
#if BX_CPU_LEVEL >= 5
  supportMask |= (EFlagsVIPMask | EFlagsVIFMask); // VIP/VIF
#endif

  // Screen out changing of any unsupported bits.
  changeMask &= supportMask;

  Bit32u newEFlags = (read_eflags() & ~changeMask) | (flags & changeMask);
  setEFlags(newEFlags);
}

  void BX_CPP_AttrRegparmN(3)
BX_CPU_C::write_flags(Bit16u flags, bx_bool change_IOPL, bx_bool change_IF)
{
  // Build a mask of the following bits:
  // x,NT,IOPL,OF,DF,IF,TF,SF,ZF,x,AF,x,PF,x,CF
  Bit32u changeMask = 0x0dd5;

#if BX_CPU_LEVEL >= 3
  changeMask |= EFlagsNTMask;     // NT is modified as requested.
  if (change_IOPL)
    changeMask |= EFlagsIOPLMask; // IOPL is modified as requested.
#endif
  if (change_IF)
    changeMask |= EFlagsIFMask;

  writeEFlags(Bit32u(flags), changeMask);
}

// Cause arithmetic flags to be in known state and cached in val32.
Bit32u BX_CPU_C::force_flags(void)
{
  Bit32u newflags  = getB_CF();
         newflags |= getB_PF() << 2;
         newflags |= getB_AF() << 4;
         newflags |= getB_ZF() << 6;
         newflags |= getB_SF() << 7;
         newflags |= getB_OF() << 11;

  BX_CPU_THIS_PTR eflags = (BX_CPU_THIS_PTR eflags & ~EFlagsOSZAPCMask)
    | (newflags & EFlagsOSZAPCMask);

  return BX_CPU_THIS_PTR eflags;
}

void BX_CPU_C::handleInterruptMaskChange(void)
{
  if (BX_CPU_THIS_PTR get_IF()) {
    // EFLAGS.IF was set, unmask all affected events
    unmask_event(BX_EVENT_VMX_INTERRUPT_WINDOW_EXITING |
                 BX_EVENT_PENDING_INTR |
                 BX_EVENT_PENDING_LAPIC_INTR |
                 BX_EVENT_PENDING_VMX_VIRTUAL_INTR);

#if BX_SUPPORT_SVM
    if (BX_CPU_THIS_PTR in_svm_guest) {
      if ((SVM_V_INTR_PRIO > SVM_V_TPR) || SVM_V_IGNORE_TPR)
        unmask_event(BX_EVENT_SVM_VIRQ_PENDING);
    }
#endif

    return;
  }
 
  // EFLAGS.IF was cleared, some events like INTR would be masked

#if BX_SUPPORT_VMX
  if (BX_CPU_THIS_PTR in_vmx_guest && PIN_VMEXIT(VMX_VM_EXEC_CTRL1_EXTERNAL_INTERRUPT_VMEXIT)) {
     // if 'External-interrupt exiting' control is set, the value of EFLAGS.IF
     // doesn't affect interrupt blocking
     mask_event(BX_EVENT_VMX_INTERRUPT_WINDOW_EXITING | BX_EVENT_PENDING_VMX_VIRTUAL_INTR);
     unmask_event(BX_EVENT_PENDING_INTR | BX_EVENT_PENDING_LAPIC_INTR);
     return;
  }
#endif

#if BX_SUPPORT_SVM
  if (BX_CPU_THIS_PTR in_svm_guest && SVM_V_INTR_MASKING) {
     if (! SVM_HOST_IF)
       mask_event(BX_EVENT_PENDING_INTR | BX_EVENT_PENDING_LAPIC_INTR);

     mask_event(BX_EVENT_SVM_VIRQ_PENDING);
  }
  else
#endif
  {
     mask_event(BX_EVENT_VMX_INTERRUPT_WINDOW_EXITING |
                BX_EVENT_PENDING_INTR |
                BX_EVENT_PENDING_LAPIC_INTR |
                BX_EVENT_PENDING_VMX_VIRTUAL_INTR |
                BX_EVENT_SVM_VIRQ_PENDING);
  }
}
