misc_helpers.S

/*
 * Copyright (c) 2013-2014, ARM Limited and Contributors. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * Redistributions of source code must retain the above copyright notice, this
 * list of conditions and the following disclaimer.
 *
 * Redistributions in binary form must reproduce the above copyright notice,
 * this list of conditions and the following disclaimer in the documentation
 * and/or other materials provided with the distribution.
 *
 * Neither the name of ARM nor the names of its contributors may be used
 * to endorse or promote products derived from this software without specific
 * prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 */

#include <arch_helpers.h>
#include <runtime_svc.h>

	.globl	enable_irq
	.globl	disable_irq

	.globl	enable_fiq
	.globl	disable_fiq

	.globl	enable_serror
	.globl	disable_serror

	.globl	enable_debug_exceptions
	.globl	disable_debug_exceptions

	.globl	read_daif
	.globl	write_daif

	.globl	read_spsr
	.globl	read_spsr_el1
	.globl	read_spsr_el2
	.globl	read_spsr_el3

	.globl	write_spsr
	.globl	write_spsr_el1
	.globl	write_spsr_el2
	.globl	write_spsr_el3

	.globl	read_elr
	.globl	read_elr_el1
	.globl	read_elr_el2
	.globl	read_elr_el3

	.globl	write_elr
	.globl	write_elr_el1
	.globl	write_elr_el2
	.globl	write_elr_el3

	.globl	get_afflvl_shift
	.globl	mpidr_mask_lower_afflvls
	.globl	dsb
	.globl	isb
	.globl	sev
	.globl	wfe
	.globl	wfi
	.globl	eret
	.globl	smc

	.globl	zeromem16
	.globl	memcpy16

	.section	.text, "ax"

get_afflvl_shift: ; .type get_afflvl_shift, %function
	cmp	x0, #3
	cinc	x0, x0, eq
	mov	x1, #MPIDR_AFFLVL_SHIFT
	lsl	x0, x0, x1
	ret

mpidr_mask_lower_afflvls: ; .type mpidr_mask_lower_afflvls, %function
	cmp	x1, #3
	cinc	x1, x1, eq
	mov	x2, #MPIDR_AFFLVL_SHIFT
	lsl	x2, x1, x2
	lsr	x0, x0, x2
	lsl	x0, x0, x2
	ret

	/* -----------------------------------------------------
	 * Asynchronous exception manipulation accessors
	 * -----------------------------------------------------
	 */
enable_irq: ; .type enable_irq, %function
	msr	daifclr, #DAIF_IRQ_BIT
	ret


enable_fiq: ; .type enable_fiq, %function
	msr	daifclr, #DAIF_FIQ_BIT
	ret


enable_serror: ; .type enable_serror, %function
	msr	daifclr, #DAIF_ABT_BIT
	ret


enable_debug_exceptions:
	msr	daifclr, #DAIF_DBG_BIT
	ret


disable_irq: ; .type disable_irq, %function
	msr	daifset, #DAIF_IRQ_BIT
	ret


disable_fiq: ; .type disable_fiq, %function
	msr	daifset, #DAIF_FIQ_BIT
	ret


disable_serror: ; .type disable_serror, %function
	msr	daifset, #DAIF_ABT_BIT
	ret


disable_debug_exceptions:
	msr	daifset, #DAIF_DBG_BIT
	ret


read_daif: ; .type read_daif, %function
	mrs	x0, daif
	ret


write_daif: ; .type write_daif, %function
	msr	daif, x0
	ret


read_spsr: ; .type read_spsr, %function
	mrs	x0, CurrentEl
	cmp	x0, #(MODE_EL1 << MODE_EL_SHIFT)
	b.eq	read_spsr_el1
	cmp	x0, #(MODE_EL2 << MODE_EL_SHIFT)
	b.eq	read_spsr_el2
	cmp	x0, #(MODE_EL3 << MODE_EL_SHIFT)
	b.eq	read_spsr_el3


read_spsr_el1: ; .type read_spsr_el1, %function
	mrs	x0, spsr_el1
	ret


read_spsr_el2: ; .type read_spsr_el2, %function
	mrs	x0, spsr_el2
	ret


read_spsr_el3: ; .type read_spsr_el3, %function
	mrs	x0, spsr_el3
	ret


write_spsr: ; .type write_spsr, %function
	mrs	x1, CurrentEl
	cmp	x1, #(MODE_EL1 << MODE_EL_SHIFT)
	b.eq	write_spsr_el1
	cmp	x1, #(MODE_EL2 << MODE_EL_SHIFT)
	b.eq	write_spsr_el2
	cmp	x1, #(MODE_EL3 << MODE_EL_SHIFT)
	b.eq	write_spsr_el3


write_spsr_el1: ; .type write_spsr_el1, %function
	msr	spsr_el1, x0
	isb
	ret


write_spsr_el2: ; .type write_spsr_el2, %function
	msr	spsr_el2, x0
	isb
	ret


write_spsr_el3: ; .type write_spsr_el3, %function
	msr	spsr_el3, x0
	isb
	ret


read_elr: ; .type read_elr, %function
	mrs	x0, CurrentEl
	cmp	x0, #(MODE_EL1 << MODE_EL_SHIFT)
	b.eq	read_elr_el1
	cmp	x0, #(MODE_EL2 << MODE_EL_SHIFT)
	b.eq	read_elr_el2
	cmp	x0, #(MODE_EL3 << MODE_EL_SHIFT)
	b.eq	read_elr_el3


read_elr_el1: ; .type read_elr_el1, %function
	mrs	x0, elr_el1
	ret


read_elr_el2: ; .type read_elr_el2, %function
	mrs	x0, elr_el2
	ret


read_elr_el3: ; .type read_elr_el3, %function
	mrs	x0, elr_el3
	ret


write_elr: ; .type write_elr, %function
	mrs	x1, CurrentEl
	cmp	x1, #(MODE_EL1 << MODE_EL_SHIFT)
	b.eq	write_elr_el1
	cmp	x1, #(MODE_EL2 << MODE_EL_SHIFT)
	b.eq	write_elr_el2
	cmp	x1, #(MODE_EL3 << MODE_EL_SHIFT)
	b.eq	write_elr_el3


write_elr_el1: ; .type write_elr_el1, %function
	msr	elr_el1, x0
	isb
	ret


write_elr_el2: ; .type write_elr_el2, %function
	msr	elr_el2, x0
	isb
	ret


write_elr_el3: ; .type write_elr_el3, %function
	msr	elr_el3, x0
	isb
	ret


dsb: ; .type dsb, %function
	dsb	sy
	ret


isb: ; .type isb, %function
	isb
	ret


sev: ; .type sev, %function
	sev
	ret


wfe: ; .type wfe, %function
	wfe
	ret


wfi: ; .type wfi, %function
	wfi
	ret


eret: ; .type eret, %function
	eret


smc: ; .type smc, %function
	smc	#0

/* -----------------------------------------------------------------------
 * void zeromem16(void *mem, unsigned int length);
 *
 * Initialise a memory region to 0.
 * The memory address must be 16-byte aligned.
 * -----------------------------------------------------------------------
 */
zeromem16:
	add	x2, x0, x1
/* zero 16 bytes at a time */
z_loop16:
	sub	x3, x2, x0
	cmp	x3, #16
	b.lt	z_loop1
	stp	xzr, xzr, [x0], #16
	b	z_loop16
/* zero byte per byte */
z_loop1:
	cmp	x0, x2
	b.eq	z_end
	strb	wzr, [x0], #1
	b	z_loop1
z_end:	ret


/* --------------------------------------------------------------------------
 * void memcpy16(void *dest, const void *src, unsigned int length)
 *
 * Copy length bytes from memory area src to memory area dest.
 * The memory areas should not overlap.
 * Destination and source addresses must be 16-byte aligned.
 * --------------------------------------------------------------------------
 */
memcpy16:
/* copy 16 bytes at a time */
m_loop16:
	cmp	x2, #16
	b.lt	m_loop1
	ldp	x3, x4, [x1], #16
	stp	x3, x4, [x0], #16
	sub	x2, x2, #16
	b	m_loop16
/* copy byte per byte */
m_loop1:
	cbz	x2, m_end
	ldrb	w3, [x1], #1
	strb	w3, [x0], #1
	subs	x2, x2, #1
	b.ne	m_loop1
m_end:	ret