zephyr/arch/sparc/core/window_trap.S

76 lines
1.6 KiB
ArmAsm

/*
* Copyright (c) 2019-2020 Cobham Gaisler AB
*
* SPDX-License-Identifier: Apache-2.0
*/
/*
* This file contains standard handlers for the SPARC V8 window overflow and
* underflow traps.
*/
#include <toolchain.h>
#include <linker/sections.h>
GTEXT(__sparc_trap_window_overflow)
GTEXT(__sparc_trap_window_underflow)
SECTION_FUNC(TEXT, __sparc_trap_window_overflow)
/* Enter the window to be stored. */
save
/* Save local register set. */
std %l0, [%sp + 0x00]
std %l2, [%sp + 0x08]
std %l4, [%sp + 0x10]
rd %wim, %l3
std %l6, [%sp + 0x18]
/* l2 := WIM << (NWIN-1) */
sll %l3, (CONFIG_SPARC_NWIN-1), %l2
/* Save input register set. */
std %i0, [%sp + 0x20]
/* l3 := WIM >> 1 */
srl %l3, 1, %l3
std %i2, [%sp + 0x28]
/* WIM := (WIM >> 1) ^ (WIM << (NWIN-1)) */
wr %l3, %l2, %wim
/* NOTE: 3 instruction before restore (delayed write instruction) */
std %i4, [%sp + 0x30]
nop
std %i6, [%sp + 0x38]
/* Go back to trap window. */
restore
/* Re-execute save. */
jmp %l1
rett %l2
SECTION_FUNC(TEXT, __sparc_trap_window_underflow)
rd %wim, %l3
/* l4 := WIM << 1 */
sll %l3, 1, %l4
/* l5 := WIM >> (NWIN-1) */
srl %l3, (CONFIG_SPARC_NWIN-1), %l5
/* WIM := (WIM << 1) ^ (WIM >> (NWIN-1)) */
wr %l4, %l5, %wim
/* WIM is implicitly read so nops are needed. */
nop
nop
nop
/* Enter the window to restore requires two restore instructions. */
restore
restore
ldd [%sp + 0x00], %l0
ldd [%sp + 0x08], %l2
ldd [%sp + 0x10], %l4
ldd [%sp + 0x18], %l6
ldd [%sp + 0x20], %i0
ldd [%sp + 0x28], %i2
ldd [%sp + 0x30], %i4
ldd [%sp + 0x38], %i6
/* Go back to the trap window. */
save
save
/* Re-execute restore. */
jmp %l1
rett %l2