fpu.c File Reference

Floating Point Unit (FPU). More...

Macros
#define	__DEBUG_HEADER__   "[FPU ]"
	Change header.
#define	__DEBUG_LEVEL__   LOGLEVEL_NOTICE
	Set log level.

Functions
static void	__set_fpu_cw (const uint16_t cw)
	Set the FPU control word. More...
static void	__enable_fpu (void)
	Enable the FPU and SSE.
static void	__disable_fpu (void)
	Disable FPU and SSE so it traps to the kernel.
static void	__restore_fpu (task_struct *proc)
	Restore the FPU for a process. More...
static void	__save_fpu (task_struct *proc)
	Save the FPU for a process. More...
static void	__init_fpu (void)
	Initialize the FPU.
static void	__invalid_op (pt_regs *f)
static void	__sigfpe_handler (pt_regs *f)
static int	__fpu_test (void)
	Ensure basic FPU functionality works. More...
void	switch_fpu (void)
	Called during a context switch to save the FPU registers status of the currently running thread.
void	unswitch_fpu (void)
	Called during a context switch to load the FPU registers status of the currently running thread inside the FPU.
int	fpu_install (void)
	Enable the FPU context handling. More...

Variables
task_struct *	thread_using_fpu = NULL
	Pointerst to the current thread using the FPU.
uint8_t saves[512]	_syscall0 = _syscall0( (aligned(16)) )= _syscall1( (aligned(16)) )= _syscall2( (aligned(16)) )= _syscall3( (aligned(16)) )=
	Temporary aligned buffer for copying around FPU contexts.

Detailed Description

Floating Point Unit (FPU).

Copyright

(c) 2014-2024 This file is distributed under the MIT License. See LICENSE.md for details.

Function Documentation

__fpu_test()

static int __fpu_test ( void  )

static

Ensure basic FPU functionality works.

For processors without a FPU, this tests that maths libraries link correctly.

Returns

1 on success, 0 on failure.

__invalid_op()

static void __invalid_op ( pt_regs *  f )

inlinestatic

Kernel trap for FPU usage when FPU is disabled.

Parameters

f	The interrupt stack frame.

__restore_fpu()

static void __restore_fpu ( task_struct *  proc )

inlinestatic

Restore the FPU for a process.

Parameters

proc	the process for which we are restoring the FPU registers.

__save_fpu()

static void __save_fpu ( task_struct *  proc )

inlinestatic

Save the FPU for a process.

Parameters

proc	the process for which we are saving the FPU registers.

__set_fpu_cw()

static void __set_fpu_cw ( const uint16_t  cw )

inlinestatic

Set the FPU control word.

Parameters

cw	What to set the control word to.

__sigfpe_handler()

static void __sigfpe_handler ( pt_regs *  f )

inlinestatic

Kernel trap for various integer and floating-point errors

Parameters

f	The interrupt stack frame.