// Copyright (c) 2026 Petr Balvín <opensource@petrbalvin.org> (https://petrbalvin.org)
// SPDX-License-Identifier: BSD-3-Clause

// Differential kernel for the arm64 system instructions: barriers,
// cache maintenance, the system register accesses, supervisor calls,
// breakpoints and prefetches.  Every function is byte-compared against
// go tool asm.

#include "textflag.h"

// func barriers()
TEXT ·barriers(SB), NOSPLIT, $0-0
	DMB $15
	DMB $1
	DSB $15
	DSB $4
	ISB $15
	ISB $1
	RET

// func cacheOps()
TEXT ·cacheOps(SB), NOSPLIT, $0-0
	DC  ZVA, R4
	DC  IVAC, R1
	DC  CVAC, R2
	DC  CVAU, R3
	DC  CIVAC, R7
	RET

// func sysRegs()
TEXT ·sysRegs(SB), NOSPLIT, $0-0
	MRS DCZID_EL0, R3
	MRS CNTVCT_EL0, R0
	MRS CNTPCT_EL0, R1
	MRS CNTFRQ_EL0, R2
	MRS MIDR_EL1, R0
	MRS ID_AA64PFR0_EL1, R0
	MRS ID_AA64ISAR0_EL1, R0
	MRS ID_AA64ISAR1_EL1, R0
	MRS DIT, R0
	MSR $3, SPSel
	MSR $9, DAIFSet
	MSR $6, DAIFClr
	MSR $1, DIT
	RET

// func exceptions()
TEXT ·exceptions(SB), NOSPLIT, $0-0
	SVC $0
	SVC $7165
	BRK
	BRK $35943
	RET

// func prefetch()
TEXT ·prefetch(SB), NOSPLIT, $0-0
	PRFM (R0), PLDL1KEEP
	PRFM (R3), PLDL3KEEP
	PRFM (R4), PSTL1KEEP
	PRFM (R2), $25
	RET