/**
* @file
*
* @brief SuperH CPU Context
*/
/*
* Authors: Ralf Corsepius (corsepiu@faw.uni-ulm.de) and
* Bernd Becker (becker@faw.uni-ulm.de)
*
* COPYRIGHT (c) 1997-1998, FAW Ulm, Germany
*
* This program 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.
*
* COPYRIGHT (c) 1998.
* On-Line Applications Research Corporation (OAR).
*
* The license and distribution terms for this file may be
* found in the file LICENSE in this distribution or at
* http://www.rtems.org/license/LICENSE.
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <rtems/system.h>
#include <rtems/score/cpu.h>
#include <rtems/score/isr.h>
#include <rtems/score/thread.h>
#include <rtems/score/sh.h>
/*
* _CPU_Context_save_fp_context
*
* This routine is responsible for saving the FP context
* at *fp_context_ptr. If the point to load the FP context
* from is changed then the pointer is modified by this routine.
*
* Sometimes a macro implementation of this is in cpu.h which dereferences
* the ** and a similarly named routine in this file is passed something
* like a (Context_Control_fp *). The general rule on making this decision
* is to avoid writing assembly language.
*/
void _CPU_Context_save_fp(
Context_Control_fp **fp_context_ptr
)
{
#if SH_HAS_FPU
asm volatile("\n\
mov.l @%0,r4 \n\
add %1,r4\n\
sts.l fpscr,@-r4\n\
sts.l fpul,@-r4\n\
lds %2,fpscr\n\
fmov dr14,@-r4\n\
fmov dr12,@-r4\n\
fmov dr10,@-r4\n\
fmov dr8,@-r4\n\
fmov dr6,@-r4\n\
fmov dr4,@-r4\n\
fmov dr2,@-r4\n\
fmov dr0,@-r4\n\
"
#ifdef SH4_USE_X_REGISTERS
"\
lds %3,fpscr\n\
fmov xd14,@-r4\n\
fmov xd12,@-r4\n\
fmov xd10,@-r4\n\
fmov xd8,@-r4\n\
fmov xd6,@-r4\n\
fmov xd4,@-r4\n\
fmov xd2,@-r4\n\
fmov xd0,@-r4\n\
"
#endif
"lds %4,fpscr\n\
"
:
: "r"(fp_context_ptr), "r"(sizeof(Context_Control_fp)),
"r"(SH4_FPSCR_SZ), "r"(SH4_FPSCR_PR | SH4_FPSCR_SZ), "r"(SH4_FPSCR_PR)
: "r4", "r0");
#endif
}
/*
* _CPU_Context_restore_fp_context
*
* This routine is responsible for restoring the FP context
* at *fp_context_ptr. If the point to load the FP context
* from is changed then the pointer is modified by this routine.
*
* Sometimes a macro implementation of this is in cpu.h which dereferences
* the ** and a similarly named routine in this file is passed something
* like a (Context_Control_fp *). The general rule on making this decision
* is to avoid writing assembly language.
*/
void _CPU_Context_restore_fp(
Context_Control_fp **fp_context_ptr
)
{
#if SH_HAS_FPU
asm volatile("\n\
mov.l @%0,r4 \n\
"
#ifdef SH4_USE_X_REGISTERS
"\n\
lds %1,fpscr\n\
fmov @r4+,xd0\n\
fmov @r4+,xd2\n\
fmov @r4+,xd4\n\
fmov @r4+,xd6\n\
fmov @r4+,xd8\n\
fmov @r4+,xd10\n\
fmov @r4+,xd12\n\
fmov @r4+,xd14\n\
"
#endif
"\n\
lds %2,fpscr\n\
fmov @r4+,dr0\n\
fmov @r4+,dr2\n\
fmov @r4+,dr4\n\
fmov @r4+,dr6\n\
fmov @r4+,dr8\n\
fmov @r4+,dr10\n\
fmov @r4+,dr12\n\
fmov @r4+,dr14\n\
lds.l @r4+,fpul\n\
lds.l @r4+,fpscr\n\
" :
: "r"(fp_context_ptr), "r"(SH4_FPSCR_PR | SH4_FPSCR_SZ), "r"(SH4_FPSCR_SZ)
: "r4", "r0");
#endif
}
/* _CPU_Context_switch
*
* This routine performs a normal non-FP context switch.
*/
/* within __CPU_Context_switch:
* _CPU_Context_switch
* _CPU_Context_restore
*
* This routine is generally used only to restart self in an
* efficient manner. It may simply be a label in _CPU_Context_switch.
*
* NOTE: It should be safe not to store r4, r5
*
* NOTE: It is doubtful if r0 is really needed to be stored
*
* NOTE: gbr is added, but should not be necessary, as it is
* only used globally in this port.
*/
/*
* FIXME: This is an ugly hack, but we wanted to avoid recalculating
* the offset each time Context_Control is changed
*/
void _CPU_Context_switch(
Context_Control *run, /* r4 */
Context_Control *heir /* r5 */
)
{
asm volatile("\n\
.global __CPU_Context_switch\n\
__CPU_Context_switch:\n\
\n\
add %0,r4\n\
\n\
stc.l sr,@-r4\n\
stc.l gbr,@-r4\n\
mov.l r0,@-r4\n\
mov.l r1,@-r4\n\
mov.l r2,@-r4\n\
mov.l r3,@-r4\n\
\n\
mov.l r6,@-r4\n\
mov.l r7,@-r4\n\
mov.l r8,@-r4\n\
mov.l r9,@-r4\n\
mov.l r10,@-r4\n\
mov.l r11,@-r4\n\
mov.l r12,@-r4\n\
mov.l r13,@-r4\n\
mov.l r14,@-r4\n\
sts.l pr,@-r4\n\
sts.l mach,@-r4\n\
sts.l macl,@-r4\n\
mov.l r15,@-r4\n\
\n\
mov r5, r4"
:: "i" (sizeof(Context_Control))
);
__asm__ volatile("\n\
.global __CPU_Context_restore\n\
__CPU_Context_restore:\n\
mov.l @r4+,r15\n\
lds.l @r4+,macl\n\
lds.l @r4+,mach\n\
lds.l @r4+,pr\n\
mov.l @r4+,r14\n\
mov.l @r4+,r13\n\
mov.l @r4+,r12\n\
mov.l @r4+,r11\n\
mov.l @r4+,r10\n\
mov.l @r4+,r9\n\
mov.l @r4+,r8\n\
mov.l @r4+,r7\n\
mov.l @r4+,r6\n\
\n\
mov.l @r4+,r3\n\
mov.l @r4+,r2\n\
mov.l @r4+,r1\n\
mov.l @r4+,r0\n\
ldc.l @r4+,gbr\n\
ldc.l @r4+,sr\n\
\n\
rts\n\
nop" );
}
