linux_dsm_epyc7002/arch/xtensa/include/asm/asmmacro.h
Max Filippov d6d5f19e21 xtensa: abstract 'entry' and 'retw' in assembly code
Provide abi_entry, abi_entry_default, abi_ret and abi_ret_default macros
that allocate aligned stack frame in windowed and call0 ABIs.
Provide XTENSA_SPILL_STACK_RESERVE macro that specifies required stack
frame size when register spilling is involved.
Replace all uses of 'entry' and 'retw' with the above macros.
This makes most of the xtensa assembly code ready for XEA3 and call0 ABI.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>
2019-07-08 10:04:48 -07:00

241 lines
4.6 KiB
C

/*
* include/asm-xtensa/asmmacro.h
*
* This file is subject to the terms and conditions of the GNU General Public
* License. See the file "COPYING" in the main directory of this archive
* for more details.
*
* Copyright (C) 2005 Tensilica Inc.
*/
#ifndef _XTENSA_ASMMACRO_H
#define _XTENSA_ASMMACRO_H
#include <asm/core.h>
/*
* Some little helpers for loops. Use zero-overhead-loops
* where applicable and if supported by the processor.
*
* __loopi ar, at, size, inc
* ar register initialized with the start address
* at scratch register used by macro
* size size immediate value
* inc increment
*
* __loops ar, as, at, inc_log2[, mask_log2][, cond][, ncond]
* ar register initialized with the start address
* as register initialized with the size
* at scratch register use by macro
* inc_log2 increment [in log2]
* mask_log2 mask [in log2]
* cond true condition (used in loop'cond')
* ncond false condition (used in b'ncond')
*
* __loop as
* restart loop. 'as' register must not have been modified!
*
* __endla ar, as, incr
* ar start address (modified)
* as scratch register used by __loops/__loopi macros or
* end address used by __loopt macro
* inc increment
*/
/*
* loop for given size as immediate
*/
.macro __loopi ar, at, size, incr
#if XCHAL_HAVE_LOOPS
movi \at, ((\size + \incr - 1) / (\incr))
loop \at, 99f
#else
addi \at, \ar, \size
98:
#endif
.endm
/*
* loop for given size in register
*/
.macro __loops ar, as, at, incr_log2, mask_log2, cond, ncond
#if XCHAL_HAVE_LOOPS
.ifgt \incr_log2 - 1
addi \at, \as, (1 << \incr_log2) - 1
.ifnc \mask_log2,
extui \at, \at, \incr_log2, \mask_log2
.else
srli \at, \at, \incr_log2
.endif
.endif
loop\cond \at, 99f
#else
.ifnc \mask_log2,
extui \at, \as, \incr_log2, \mask_log2
.else
.ifnc \ncond,
srli \at, \as, \incr_log2
.endif
.endif
.ifnc \ncond,
b\ncond \at, 99f
.endif
.ifnc \mask_log2,
slli \at, \at, \incr_log2
add \at, \ar, \at
.else
add \at, \ar, \as
.endif
#endif
98:
.endm
/*
* loop from ar to as
*/
.macro __loopt ar, as, at, incr_log2
#if XCHAL_HAVE_LOOPS
sub \at, \as, \ar
.ifgt \incr_log2 - 1
addi \at, \at, (1 << \incr_log2) - 1
srli \at, \at, \incr_log2
.endif
loop \at, 99f
#else
98:
#endif
.endm
/*
* restart loop. registers must be unchanged
*/
.macro __loop as
#if XCHAL_HAVE_LOOPS
loop \as, 99f
#else
98:
#endif
.endm
/*
* end of loop with no increment of the address.
*/
.macro __endl ar, as
#if !XCHAL_HAVE_LOOPS
bltu \ar, \as, 98b
#endif
99:
.endm
/*
* end of loop with increment of the address.
*/
.macro __endla ar, as, incr
addi \ar, \ar, \incr
__endl \ar \as
.endm
/* Load or store instructions that may cause exceptions use the EX macro. */
#define EX(handler) \
.section __ex_table, "a"; \
.word 97f, handler; \
.previous \
97:
/*
* Extract unaligned word that is split between two registers w0 and w1
* into r regardless of machine endianness. SAR must be loaded with the
* starting bit of the word (see __ssa8).
*/
.macro __src_b r, w0, w1
#ifdef __XTENSA_EB__
src \r, \w0, \w1
#else
src \r, \w1, \w0
#endif
.endm
/*
* Load 2 lowest address bits of r into SAR for __src_b to extract unaligned
* word starting at r from two registers loaded from consecutive aligned
* addresses covering r regardless of machine endianness.
*
* r 0 1 2 3
* LE SAR 0 8 16 24
* BE SAR 32 24 16 8
*/
.macro __ssa8 r
#ifdef __XTENSA_EB__
ssa8b \r
#else
ssa8l \r
#endif
.endm
#define XTENSA_STACK_ALIGNMENT 16
#if defined(__XTENSA_WINDOWED_ABI__)
#define XTENSA_FRAME_SIZE_RESERVE 16
#define XTENSA_SPILL_STACK_RESERVE 32
#define abi_entry(frame_size) \
entry sp, (XTENSA_FRAME_SIZE_RESERVE + \
(((frame_size) + XTENSA_STACK_ALIGNMENT - 1) & \
-XTENSA_STACK_ALIGNMENT))
#define abi_entry_default abi_entry(0)
#define abi_ret(frame_size) retw
#define abi_ret_default retw
#elif defined(__XTENSA_CALL0_ABI__)
#define XTENSA_SPILL_STACK_RESERVE 0
#define abi_entry(frame_size) __abi_entry (frame_size)
.macro __abi_entry frame_size
.ifgt \frame_size
addi sp, sp, -(((\frame_size) + XTENSA_STACK_ALIGNMENT - 1) & \
-XTENSA_STACK_ALIGNMENT)
.endif
.endm
#define abi_entry_default
#define abi_ret(frame_size) __abi_ret (frame_size)
.macro __abi_ret frame_size
.ifgt \frame_size
addi sp, sp, (((\frame_size) + XTENSA_STACK_ALIGNMENT - 1) & \
-XTENSA_STACK_ALIGNMENT)
.endif
ret
.endm
#define abi_ret_default ret
#else
#error Unsupported Xtensa ABI
#endif
#endif /* _XTENSA_ASMMACRO_H */