zephyr/arch/xtensa/include/xtensa-asm2-context.h

149 lines
4.3 KiB
C

/*
* Copyright (c) 2017, Intel Corporation
*
* SPDX-License-Identifier: Apache-2.0
*/
#ifndef ZEPHYR_ARCH_XTENSA_INCLUDE_XTENSA_ASM2_CONTEXT_H_
#define ZEPHYR_ARCH_XTENSA_INCLUDE_XTENSA_ASM2_CONTEXT_H_
#include <xtensa/corebits.h>
#include <xtensa/config/core-isa.h>
/*
* Stack frame layout for a saved processor context, in memory order,
* high to low address:
*
* SP-0 <-- Interrupted stack pointer points here
*
* SP-4 Caller A3 spill slot \
* SP-8 Caller A2 spill slot |
* SP-12 Caller A1 spill slot + (Part of ABI standard)
* SP-16 Caller A0 spill slot /
*
* SP-20 Saved A3
* SP-24 Saved A2
* SP-28 Unused (not "Saved A1" because the SP is saved externally as a handle)
* SP-32 Saved A0
*
* SP-36 Saved PC (address to jump to following restore)
* SP-40 Saved/interrupted PS special register
*
* SP-44 Saved SAR special register
*
* SP-48 Saved LBEG special register (if loops enabled)
* SP-52 Saved LEND special register (if loops enabled)
* SP-56 Saved LCOUNT special register (if loops enabled)
*
* SP-60 Saved SCOMPARE special register (if S32C1I enabled)
*
* (The above fixed-size region is known as the "base save area" in the
* code below)
*
* - Saved A7 \
* - Saved A6 |
* - Saved A5 +- If not in-use by another frame
* - Saved A4 /
*
* - Saved A11 \
* - Saved A10 |
* - Saved A9 +- If not in-use by another frame
* - Saved A8 /
*
* - Saved A15 \
* - Saved A14 |
* - Saved A13 +- If not in-use by another frame
* - Saved A12 /
*
* - Saved intermediate stack pointer (points to low word of base save
* area, i.e. the saved LCOUNT or SAR). The pointer to this value
* (i.e. the final stack pointer) is stored externally as the
* "restore handle" in the thread context.
*
* Essentially, you can recover a pointer to the BSA by loading *SP.
* Adding the fixed BSA size to that gets you back to the
* original/interrupted stack pointer.
*/
#define BASE_SAVE_AREA_SIZE_COMMON 44
#define BASE_SAVE_AREA_SIZE_EXCCAUSE 4
#if XCHAL_HAVE_LOOPS
#define BASE_SAVE_AREA_SIZE_LOOPS 12
#else
#define BASE_SAVE_AREA_SIZE_LOOPS 0
#endif
#if XCHAL_HAVE_S32C1I
#define BASE_SAVE_AREA_SIZE_SCOMPARE 4
#else
#define BASE_SAVE_AREA_SIZE_SCOMPARE 0
#endif
#if XCHAL_HAVE_THREADPTR && defined(CONFIG_THREAD_LOCAL_STORAGE)
#define BASE_SAVE_AREA_SIZE_THREADPTR 4
#else
#define BASE_SAVE_AREA_SIZE_THREADPTR 0
#endif
#if XCHAL_HAVE_FP && defined(CONFIG_CPU_HAS_FPU) && defined(CONFIG_FPU_SHARING)
#define BASE_SAVE_AREA_SIZE_FPU (18 * 4)
#else
#define BASE_SAVE_AREA_SIZE_FPU 0
#endif
#define BASE_SAVE_AREA_SIZE \
(BASE_SAVE_AREA_SIZE_COMMON + \
BASE_SAVE_AREA_SIZE_LOOPS + \
BASE_SAVE_AREA_SIZE_EXCCAUSE + \
BASE_SAVE_AREA_SIZE_SCOMPARE + \
BASE_SAVE_AREA_SIZE_THREADPTR + \
BASE_SAVE_AREA_SIZE_FPU)
#define BSA_A3_OFF (BASE_SAVE_AREA_SIZE - 20)
#define BSA_A2_OFF (BASE_SAVE_AREA_SIZE - 24)
#define BSA_SCRATCH_OFF (BASE_SAVE_AREA_SIZE - 28)
#define BSA_A0_OFF (BASE_SAVE_AREA_SIZE - 32)
#define BSA_PC_OFF (BASE_SAVE_AREA_SIZE - 36)
#define BSA_PS_OFF (BASE_SAVE_AREA_SIZE - 40)
#define BSA_SAR_OFF (BASE_SAVE_AREA_SIZE - 44)
#define BSA_LBEG_OFF (BASE_SAVE_AREA_SIZE - 48)
#define BSA_LEND_OFF (BASE_SAVE_AREA_SIZE - 52)
#define BSA_LCOUNT_OFF (BASE_SAVE_AREA_SIZE - 56)
#define BSA_EXCCAUSE_OFF \
(BASE_SAVE_AREA_SIZE - \
(BASE_SAVE_AREA_SIZE_COMMON + \
BASE_SAVE_AREA_SIZE_LOOPS + \
BASE_SAVE_AREA_SIZE_EXCCAUSE))
#if XCHAL_HAVE_S32C1I
#define BSA_SCOMPARE1_OFF \
(BASE_SAVE_AREA_SIZE - \
(BASE_SAVE_AREA_SIZE_COMMON + \
BASE_SAVE_AREA_SIZE_LOOPS + \
BASE_SAVE_AREA_SIZE_EXCCAUSE + \
BASE_SAVE_AREA_SIZE_SCOMPARE))
#endif
#if XCHAL_HAVE_THREADPTR && defined(CONFIG_THREAD_LOCAL_STORAGE)
#define BSA_THREADPTR_OFF \
(BASE_SAVE_AREA_SIZE - \
(BASE_SAVE_AREA_SIZE_COMMON + \
BASE_SAVE_AREA_SIZE_LOOPS + \
BASE_SAVE_AREA_SIZE_EXCCAUSE + \
BASE_SAVE_AREA_SIZE_SCOMPARE + \
BASE_SAVE_AREA_SIZE_THREADPTR))
#endif
#if XCHAL_HAVE_FP && defined(CONFIG_CPU_HAS_FPU) && defined(CONFIG_FPU_SHARING)
#define BSA_FPU_OFF \
(BASE_SAVE_AREA_SIZE - \
(BASE_SAVE_AREA_SIZE_COMMON + \
BASE_SAVE_AREA_SIZE_LOOPS + \
BASE_SAVE_AREA_SIZE_EXCCAUSE + \
BASE_SAVE_AREA_SIZE_SCOMPARE + \
BASE_SAVE_AREA_SIZE_THREADPTR + \
BASE_SAVE_AREA_SIZE_FPU))
#endif
#endif /* ZEPHYR_ARCH_XTENSA_INCLUDE_XTENSA_ASM2_CONTEXT_H_ */