seL4/include/machine/fpu.h
2017-02-27 06:26:58 +00:00

67 lines
2.2 KiB
C

/*
* Copyright 2016, Data61
* Commonwealth Scientific and Industrial Research Organisation (CSIRO)
* ABN 41 687 119 230.
*
* This software may be distributed and modified according to the terms of
* the GNU General Public License version 2. Note that NO WARRANTY is provided.
* See "LICENSE_GPLv2.txt" for details.
*
* @TAG(DATA61_GPL)
*/
#ifndef __MACHINE_FPU_H
#define __MACHINE_FPU_H
#include <config.h>
#include <object/structures.h>
#include <model/statedata.h>
#include <arch/machine/fpu.h>
#ifdef CONFIG_HAVE_FPU
/* Perform any actions required for the deletion of the given thread. */
void fpuThreadDelete(tcb_t *thread);
/* Handle an FPU exception. */
exception_t handleFPUFault(void);
void switchLocalFpuOwner(user_fpu_state_t *new_owner);
/* Switch the current owner of the FPU state on the core specified by 'cpu'. */
void switchFpuOwner(user_fpu_state_t *new_owner, word_t cpu);
/* Returns whether or not the passed thread is using the current active fpu state */
static inline bool_t nativeThreadUsingFPU(tcb_t *thread)
{
return &thread->tcbArch.tcbContext.fpuState ==
NODE_STATE_ON_CORE(ksActiveFPUState, thread->tcbAffinity);
}
static inline void FORCE_INLINE lazyFPURestore(tcb_t *thread)
{
if (unlikely(NODE_STATE(ksActiveFPUState))) {
/* If we have enabled/disabled the FPU too many times without
* someone else trying to use it, we assume it is no longer
* in use and switch out its state. */
if (unlikely(NODE_STATE(ksFPURestoresSinceSwitch) > CONFIG_FPU_MAX_RESTORES_SINCE_SWITCH)) {
switchLocalFpuOwner(NULL);
NODE_STATE(ksFPURestoresSinceSwitch) = 0;
} else {
if (likely(nativeThreadUsingFPU(thread))) {
/* We are using the FPU, make sure it is enabled */
enableFpu();
} else {
/* Someone is using the FPU and it might be enabled */
disableFpu();
}
NODE_STATE(ksFPURestoresSinceSwitch)++;
}
} else {
/* No-one (including us) is using the FPU, so we assume it
* is currently disabled */
}
}
#endif /* CONFIG_HAVE_FPU */
#endif /* __MACHINE_FPU_H */