0ad/source/lib/sysdep/os/win/whrt/pmt.cpp
janwas 1861448e6c needed to split lib into separate headers and source files, which requires lots of drudgery to specify paths for each include filename (no longer relying on same-directory lookups)
also rename wchar -> utf8 to avoid conflict with <wchar.h> (requires
rebuild of workspace)
(unfortunately copying history fails to "502 bad gateway"; had to delete
old + add new independently)

This was SVN commit r7340.
2010-03-01 14:52:58 +00:00

131 lines
3.4 KiB
C++

/* Copyright (c) 2010 Wildfire Games
*
* Permission is hereby granted, free of charge, to any person obtaining
* a copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, sublicense, and/or sell copies of the Software, and to
* permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included
* in all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY
* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
/*
* Timer implementation using ACPI PM timer
*/
#include "precompiled.h"
#include "lib/sysdep/os/win/whrt/pmt.h"
#include "lib/sysdep/os/win/whrt/counter.h"
#include "lib/sysdep/os/win/win.h"
#include "lib/sysdep/acpi.h"
#include "lib/sysdep/os/win/mahaf.h"
#include "lib/bits.h"
#pragma pack(push,1)
struct FADT
{
AcpiTable header;
u8 unused[40];
u32 pmTimerPortAddress;
u8 unused2[32];
u32 flags;
};
#pragma pack(pop)
static const u32 TMR_VAL_EXT = Bit<u32>(8);
//-----------------------------------------------------------------------------
class CounterPMT : public ICounter
{
public:
CounterPMT()
: m_portAddress(0xFFFF)
{
}
virtual const wchar_t* Name() const
{
return L"PMT";
}
LibError Activate()
{
// mahaf is needed for port I/O.
if(!mahaf_Init())
return ERR::FAIL; // NOWARN (no Administrator privileges)
if(!acpi_Init())
return ERR::FAIL; // NOWARN (happens on Win2k; see mahaf_IsPhysicalMappingDangerous)
// (note: it's called FADT, but the signature is "FACP")
const FADT* fadt = (const FADT*)acpi_GetTable("FACP");
if(!fadt)
WARN_RETURN(ERR::NO_SYS);
m_portAddress = u16_from_larger(fadt->pmTimerPortAddress);
return INFO::OK;
}
void Shutdown()
{
acpi_Shutdown();
mahaf_Shutdown();
}
bool IsSafe() const
{
// the PMT has one issue: "Performance counter value may unexpectedly
// leap forward" (Q274323). This happens on some buggy Pentium-era
// systems under heavy PCI bus load. We are clever and observe that
// the TSC implementation would be used on such systems (because it
// has higher precedence and is safe on P5 CPUs), so the PMT is fine
// in general.
return true;
}
u64 Counter() const
{
return mahaf_ReadPort32(m_portAddress);
}
size_t CounterBits() const
{
// (see previous acpi_GetTable call)
const FADT* fadt = (const FADT*)acpi_GetTable("FACP");
debug_assert(fadt); // Activate made sure FADT is available
const size_t counterBits = (fadt->flags & TMR_VAL_EXT)? 32 : 24;
return counterBits;
}
double NominalFrequency() const
{
return (double)PMT_FREQ;
}
double Resolution() const
{
return 1.0 / PMT_FREQ;
}
private:
u16 m_portAddress;
};
ICounter* CreateCounterPMT(void* address, size_t size)
{
debug_assert(sizeof(CounterPMT) <= size);
return new(address) CounterPMT();
}