src/arch/arm/v8/exception_asm.S

/*
 * Copyright 2014 Google Inc.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. 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.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR 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 AUTHOR 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.
 */

#define __ASSEMBLY__
#include <arch/lib_helpers.h>

	.text

	/* Macro for exception entry
	 * Store x30 before any branch
	 * Branch to exception_prologue to save rest of the registers
	 * Move exception id into x1
	 * Branch to exception_handler
	 */
.macro eentry lbl id
	.align 7
\lbl:
	stp	x30, xzr, [sp, #-16]!
	bl	exception_prologue
	mov	x1, \id
	bl	exception_handler
.endm

	/* Exception table has 16 entries and each of 128 bytes
	 * Hence, 16 * 128 = 2048. Thus, 11 passed as parameter
	 * to align
	 */

	.align  11
	.global exception_table
exception_table:

eentry	sync_sp0,#0
eentry	irq_sp0,#1
eentry	fiq_sp0,#2
eentry	serror_sp0,#3
eentry	sync_spx,#4
eentry	irq_spx,#5
eentry	fiq_spx,#6
eentry	serror_spx,#7
eentry	sync_elx_64,#8
eentry	irq_elx_64,#9
eentry	fiq_elx_64,#10
eentry	serror_elx_64,#11
eentry	sync_elx_32,#12
eentry	irq_elx_32,#13
eentry	fiq_elx_32,#14
eentry	serror_elx_32,#15

exception_prologue:
	/* Save all registers x0-x29 */
	stp     x28, x29, [sp, #-16]!
	stp     x26, x27, [sp, #-16]!
	stp     x24, x25, [sp, #-16]!
	stp     x22, x23, [sp, #-16]!
	stp     x20, x21, [sp, #-16]!
	stp     x18, x19, [sp, #-16]!
	stp     x16, x17, [sp, #-16]!
	stp     x14, x15, [sp, #-16]!
	stp     x12, x13, [sp, #-16]!
	stp     x10, x11, [sp, #-16]!
	stp     x8, x9, [sp, #-16]!
	stp     x6, x7, [sp, #-16]!
	stp     x4, x5, [sp, #-16]!
	stp     x2, x3, [sp, #-16]!
	stp     x0, x1, [sp, #-16]!

	/* Save the exception reason on stack */
	read_current x1, esr

	/* Save the return address on stack */
	read_current x0, elr
	stp     x0, x1, [sp, #-16]!

	ret

exception_handler:
	/* Save address of saved registers into x0
	 * This acts as first argument to exception_dispatch
	 */
	mov     x0, sp
	bl      exception_dispatch

	/* Pop return address saved on stack */
	ldp     x0, x1, [sp], #16
	write_current elr, x0, x2
	write_current esr, x1, x2
	/* Pop exception reason saved on stack, followed by regs x0-x30 */
	ldp     x0, x1, [sp], #16
	ldp     x2, x3, [sp], #16
	ldp     x4, x5, [sp], #16
	ldp     x6, x7, [sp], #16
	ldp     x8, x9, [sp], #16
	ldp     x10, x11, [sp], #16
	ldp     x12, x13, [sp], #16
	ldp     x14, x15, [sp], #16
	ldp     x16, x17, [sp], #16
	ldp     x18, x19, [sp], #16
	ldp     x20, x21, [sp], #16
	ldp     x22, x23, [sp], #16
	ldp     x24, x25, [sp], #16
	ldp     x26, x27, [sp], #16
	ldp     x28, x29, [sp], #16
	ldp     x30, xzr, [sp], #16
	eret

	.global set_vbar
set_vbar:
	write_current vbar, x0, x1
	ret