/*
* Copyright (c) 2015 embedded brains GmbH. All rights reserved.
*
* embedded brains GmbH
* Dornierstr. 4
* 82178 Puchheim
* Germany
* <rtems@embedded-brains.de>
*
* 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/asm.h>
#include <rtems/score/cpuimpl.h>
#define SCRATCH_0 (SPARC_MINIMUM_STACK_FRAME_SIZE)
#define SCRATCH_1 (SCRATCH_0 + 0x04)
#define FRAME_END (SCRATCH_1 + 0x04)
#define FRAME_SIZE \
((FRAME_END + CPU_STACK_ALIGNMENT - 1) & ~(CPU_STACK_ALIGNMENT - 1))
.macro clobber_register reg
sub %g2, 1, %g2
mov %g2, \reg
.endm
.macro clobber_fp_register reg
sub %g2, 1, %g2
st %g2, [%sp + SCRATCH_0]
ld [%sp + SCRATCH_0], \reg
.endm
.section ".bss"
.align 4
/*
* Use a global variable to vary the clobbered windows in each
* invocation to test the window overflow and underflow conditions.
*/
window_clobber_count:
.skip 4
.section ".text"
.align 4
PUBLIC(_CPU_Context_volatile_clobber)
SYM(_CPU_Context_volatile_clobber):
/* Increment number of flushed windows by one */
sethi %hi(window_clobber_count), %o1
ld [%o1 + %lo(window_clobber_count)], %o2
add %o2, 1, %o2
st %o2, [%o1 + %lo(window_clobber_count)]
/* Clear window counter number */
clr %g1
/* Save pattern to global register */
mov %o0, %g2
window_clobber:
/* Switch window */
save %sp, -FRAME_SIZE, %sp
/* Check how many windows shall be flushed */
sethi %hi(window_clobber_count), %o1
ld [%o1 + %lo(window_clobber_count)], %o2
st %o2, [%o1 + %lo(window_clobber_count)]
and %o2, (SPARC_NUMBER_OF_REGISTER_WINDOWS - 1), %o1
cmp %o1, 0
bne no_manual_update
nop
add %o1, SPARC_NUMBER_OF_REGISTER_WINDOWS, %o1
no_manual_update:
/* Register to determine whether FPU is switched on */
mov %psr, %o2
sethi %hi(SPARC_PSR_EF_MASK), %o3
and %o3, %o2, %o2
clobber_register %o3
clobber_register %o4
clobber_register %o5
/* Don't overwrite return address $o7 */
clobber_register %g3
clobber_register %g4
clobber_register %y
cmp %o2, 0
be window_update_check
nop
clobber_fp_register %f0
clobber_fp_register %f1
clobber_fp_register %f2
clobber_fp_register %f3
clobber_fp_register %f4
clobber_fp_register %f5
clobber_fp_register %f6
clobber_fp_register %f7
clobber_fp_register %f8
clobber_fp_register %f9
clobber_fp_register %f10
clobber_fp_register %f11
clobber_fp_register %f12
clobber_fp_register %f13
clobber_fp_register %f14
clobber_fp_register %f15
clobber_fp_register %f16
clobber_fp_register %f17
clobber_fp_register %f18
clobber_fp_register %f19
clobber_fp_register %f20
clobber_fp_register %f21
clobber_fp_register %f22
clobber_fp_register %f23
clobber_fp_register %f24
clobber_fp_register %f25
clobber_fp_register %f26
clobber_fp_register %f27
clobber_fp_register %f28
clobber_fp_register %f29
clobber_fp_register %f30
clobber_fp_register %f31
window_update_check:
/* Counter to how many windows were switched */
add %g1, 1, %g1
cmp %g1, %o1
bl window_clobber
nop
restore_check:
cmp %g1, 0
be clobber_return
nop
restore
sub %g1, 1, %g1
ba restore_check
nop
clobber_return:
jmp %o7 + 8
nop
