mirror of
https://gitlab.com/sortix/sortix.git
synced 2023-02-13 20:55:38 -05:00
88 lines
2.1 KiB
C++
88 lines
2.1 KiB
C++
/*******************************************************************************
|
|
|
|
Copyright(C) Jonas 'Sortie' Termansen 2011, 2012.
|
|
|
|
This file is part of Sortix.
|
|
|
|
Sortix is free software: you can redistribute it and/or modify it under the
|
|
terms of the GNU General Public License as published by the Free Software
|
|
Foundation, either version 3 of the License, or (at your option) any later
|
|
version.
|
|
|
|
Sortix 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 General Public License for more
|
|
details.
|
|
|
|
You should have received a copy of the GNU General Public License along with
|
|
Sortix. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
x86-family/float.cpp
|
|
Handles saving and restoration of floating point numbers.
|
|
|
|
*******************************************************************************/
|
|
|
|
#include <assert.h>
|
|
|
|
#include <sortix/kernel/interrupt.h>
|
|
#include <sortix/kernel/kernel.h>
|
|
#include <sortix/kernel/thread.h>
|
|
|
|
#include "float.h"
|
|
|
|
namespace Sortix {
|
|
namespace Float {
|
|
|
|
static Thread* fputhread;
|
|
|
|
static inline void InitFPU()
|
|
{
|
|
asm volatile ("fninit");
|
|
}
|
|
|
|
static inline void SaveState(uint8_t* dest)
|
|
{
|
|
assert( (((unsigned long) dest) & (16UL-1UL)) == 0 );
|
|
asm volatile ("fxsave (%0)" : : "r"(dest));
|
|
}
|
|
|
|
static inline void LoadState(const uint8_t* src)
|
|
{
|
|
assert( (((unsigned long) src) & (16UL-1UL)) == 0 );
|
|
asm volatile ("fxrstor (%0)" : : "r"(src));
|
|
}
|
|
|
|
static void OnFPUAccess(CPU::InterruptRegisters* /*regs*/, void* /*user*/)
|
|
{
|
|
EnableFPU();
|
|
Thread* thread = CurrentThread();
|
|
if ( thread == fputhread )
|
|
return;
|
|
if ( fputhread )
|
|
SaveState(fputhread->fpuenvaligned);
|
|
fputhread = thread;
|
|
if ( !thread->fpuinitialized )
|
|
{
|
|
InitFPU();
|
|
thread->fpuinitialized = true;
|
|
return;
|
|
}
|
|
LoadState(thread->fpuenvaligned);
|
|
}
|
|
|
|
void Init()
|
|
{
|
|
fputhread = CurrentThread();
|
|
assert(fputhread);
|
|
Interrupt::RegisterHandler(7, OnFPUAccess, NULL);
|
|
}
|
|
|
|
void NofityTaskExit(Thread* thread)
|
|
{
|
|
if ( fputhread == thread )
|
|
fputhread = NULL;
|
|
DisableFPU();
|
|
}
|
|
|
|
} // namespace Float
|
|
} // namespace Sortix
|