arm-trusted-firmware/include/arch/aarch64/asm_macros.S
Andre Przywara 387b8801f9 refactor(cpufeat): use alternative encoding for "SB" barrier
The "sb" barrier instruction is a rather new addition to the AArch64
instruction set, so it is not recognised by all toolchains. On top of
that, the GNU assembler denies this instruction, unless a compatible
processor is selected:
asm_macros.S:223: Error: selected processor does not support `sb'

Provide an alternative encoding of the "sb" instruction, by using a
system register write, as this is the group where the barrier
instructions borrow their encoding space from.
This results in the exact same opcode to be generated, and any
disassembler will decode this instruction as "sb".

Change-Id: I5f44c8321e0cc04c784e02bd838e964602a96a8e
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
2023-03-22 13:33:22 +00:00

256 lines
6 KiB
ArmAsm

/*
* Copyright (c) 2013-2020, ARM Limited and Contributors. All rights reserved.
*
* SPDX-License-Identifier: BSD-3-Clause
*/
#ifndef ASM_MACROS_S
#define ASM_MACROS_S
#include <arch.h>
#include <common/asm_macros_common.S>
#include <lib/spinlock.h>
/*
* TLBI instruction with type specifier that implements the workaround for
* errata 813419 of Cortex-A57 or errata 1286807 of Cortex-A76.
*/
#if ERRATA_A57_813419 || ERRATA_A76_1286807
#define TLB_INVALIDATE(_type) \
tlbi _type; \
dsb ish; \
tlbi _type
#else
#define TLB_INVALIDATE(_type) \
tlbi _type
#endif
.macro func_prologue
stp x29, x30, [sp, #-0x10]!
mov x29,sp
.endm
.macro func_epilogue
ldp x29, x30, [sp], #0x10
.endm
.macro dcache_line_size reg, tmp
mrs \tmp, ctr_el0
ubfx \tmp, \tmp, #16, #4
mov \reg, #4
lsl \reg, \reg, \tmp
.endm
.macro icache_line_size reg, tmp
mrs \tmp, ctr_el0
and \tmp, \tmp, #0xf
mov \reg, #4
lsl \reg, \reg, \tmp
.endm
.macro smc_check label
mrs x0, esr_el3
ubfx x0, x0, #ESR_EC_SHIFT, #ESR_EC_LENGTH
cmp x0, #EC_AARCH64_SMC
b.ne $label
.endm
/*
* Declare the exception vector table, enforcing it is aligned on a
* 2KB boundary, as required by the ARMv8 architecture.
* Use zero bytes as the fill value to be stored in the padding bytes
* so that it inserts illegal AArch64 instructions. This increases
* security, robustness and potentially facilitates debugging.
*/
.macro vector_base label, section_name=.vectors
.section \section_name, "ax"
.align 11, 0
\label:
.endm
/*
* Create an entry in the exception vector table, enforcing it is
* aligned on a 128-byte boundary, as required by the ARMv8 architecture.
* Use zero bytes as the fill value to be stored in the padding bytes
* so that it inserts illegal AArch64 instructions. This increases
* security, robustness and potentially facilitates debugging.
*/
.macro vector_entry label, section_name=.vectors
.cfi_sections .debug_frame
.section \section_name, "ax"
.align 7, 0
.type \label, %function
.cfi_startproc
\label:
.endm
/*
* Add the bytes until fill the full exception vector, whose size is always
* 32 instructions. If there are more than 32 instructions in the
* exception vector then an error is emitted.
*/
.macro end_vector_entry label
.cfi_endproc
.fill \label + (32 * 4) - .
.endm
/*
* This macro calculates the base address of the current CPU's MP stack
* using the plat_my_core_pos() index, the name of the stack storage
* and the size of each stack
* Out: X0 = physical address of stack base
* Clobber: X30, X1, X2
*/
.macro get_my_mp_stack _name, _size
bl plat_my_core_pos
adrp x2, (\_name + \_size)
add x2, x2, :lo12:(\_name + \_size)
mov x1, #\_size
madd x0, x0, x1, x2
.endm
/*
* This macro calculates the base address of a UP stack using the
* name of the stack storage and the size of the stack
* Out: X0 = physical address of stack base
*/
.macro get_up_stack _name, _size
adrp x0, (\_name + \_size)
add x0, x0, :lo12:(\_name + \_size)
.endm
/*
* Helper macro to generate the best mov/movk combinations according
* the value to be moved. The 16 bits from '_shift' are tested and
* if not zero, they are moved into '_reg' without affecting
* other bits.
*/
.macro _mov_imm16 _reg, _val, _shift
.if (\_val >> \_shift) & 0xffff
.if (\_val & (1 << \_shift - 1))
movk \_reg, (\_val >> \_shift) & 0xffff, LSL \_shift
.else
mov \_reg, \_val & (0xffff << \_shift)
.endif
.endif
.endm
/*
* Helper macro to load arbitrary values into 32 or 64-bit registers
* which generates the best mov/movk combinations. Many base addresses
* are 64KB aligned the macro will eliminate updating bits 15:0 in
* that case
*/
.macro mov_imm _reg, _val
.if (\_val) == 0
mov \_reg, #0
.else
_mov_imm16 \_reg, (\_val), 0
_mov_imm16 \_reg, (\_val), 16
_mov_imm16 \_reg, (\_val), 32
_mov_imm16 \_reg, (\_val), 48
.endif
.endm
/*
* Macro to mark instances where we're jumping to a function and don't
* expect a return. To provide the function being jumped to with
* additional information, we use 'bl' instruction to jump rather than
* 'b'.
*
* Debuggers infer the location of a call from where LR points to, which
* is usually the instruction after 'bl'. If this macro expansion
* happens to be the last location in a function, that'll cause the LR
* to point a location beyond the function, thereby misleading debugger
* back trace. We therefore insert a 'nop' after the function call for
* debug builds, unless 'skip_nop' parameter is non-zero.
*/
.macro no_ret _func:req, skip_nop=0
bl \_func
#if DEBUG
.ifeq \skip_nop
nop
.endif
#endif
.endm
/*
* Reserve space for a spin lock in assembly file.
*/
.macro define_asm_spinlock _name:req
.align SPINLOCK_ASM_ALIGN
\_name:
.space SPINLOCK_ASM_SIZE
.endm
#if RAS_EXTENSION
.macro esb
.inst 0xd503221f
.endm
#endif
/*
* Helper macro to read system register value into x0
*/
.macro read reg:req
#if ENABLE_BTI
bti j
#endif
mrs x0, \reg
ret
.endm
/*
* Helper macro to write value from x1 to system register
*/
.macro write reg:req
#if ENABLE_BTI
bti j
#endif
msr \reg, x1
ret
.endm
/*
* The "sb" instruction was introduced later into the architecture,
* so not all toolchains understand it. Some deny its usage unless
* a supported processor is specified on the build command line.
* Use sb's system register encoding to work around this, we already
* guard the sb execution with a feature flag.
*/
.macro sb_barrier_insn
msr SYSREG_SB, xzr
.endm
/*
* Macro for using speculation barrier instruction introduced by
* FEAT_SB, if it's enabled.
*/
.macro speculation_barrier
#if ENABLE_FEAT_SB
sb_barrier_insn
#else
dsb sy
isb
#endif
.endm
/*
* Macro for mitigating against speculative execution beyond ERET. Uses the
* speculation barrier instruction introduced by FEAT_SB, if it's enabled.
*/
.macro exception_return
eret
#if ENABLE_FEAT_SB
sb_barrier_insn
#else
dsb nsh
isb
#endif
.endm
#endif /* ASM_MACROS_S */