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/* SPDX-License-Identifier: GPL-2.0+ */
/*
* (C) Copyright 2013
* David Feng <fenghua@phytium.com.cn>
*/
#include <asm-offsets.h>
#include <config.h>
#include <asm/ptrace.h>
#include <asm/macro.h>
#include <linux/linkage.h>
/*
* AArch64 exception vectors:
* We have four types of exceptions:
* - synchronous: traps, data aborts, undefined instructions, ...
* - IRQ: group 1 (normal) interrupts
* - FIQ: group 0 or secure interrupts
* - SError: fatal system errors
* There are entries for all four of those for different contexts:
* - from same exception level, when using the SP_EL0 stack pointer
* - from same exception level, when using the SP_ELx stack pointer
* - from lower exception level, when this is AArch64
* - from lower exception level, when this is AArch32
* Each of those 16 entries have space for 32 instructions, each entry must
* be 128 byte aligned, the whole table must be 2K aligned.
* The 32 instructions are not enough to save and restore all registers and
* to branch to the actual handler, so we split this up:
* Each entry saves the LR, branches to the save routine, then to the actual
* handler, then to the restore routine. The save and restore routines are
* each split in half and stuffed in the unused gap between the entries.
* Also as we do not run anything in a lower exception level, we just provide
* the first 8 entries for exceptions from the same EL.
*/
.align 11
.globl vectors
vectors:
.align 7 /* Current EL Synchronous Thread */
stp x29, x30, [sp, #-16]!
bl _exception_entry
bl do_bad_sync
b exception_exit
/*
* Save (most of) the GP registers to the stack frame.
* This is the first part of the shared routine called into from all entries.
*/
_exception_entry:
stp x27, x28, [sp, #-16]!
stp x25, x26, [sp, #-16]!
stp x23, x24, [sp, #-16]!
stp x21, x22, [sp, #-16]!
stp x19, x20, [sp, #-16]!
stp x17, x18, [sp, #-16]!
stp x15, x16, [sp, #-16]!
stp x13, x14, [sp, #-16]!
stp x11, x12, [sp, #-16]!
stp x9, x10, [sp, #-16]!
stp x7, x8, [sp, #-16]!
stp x5, x6, [sp, #-16]!
stp x3, x4, [sp, #-16]!
stp x1, x2, [sp, #-16]!
b _save_el_regs /* jump to the second part */
.align 7 /* Current EL IRQ Thread */
stp x29, x30, [sp, #-16]!
bl _exception_entry
bl do_bad_irq
b exception_exit
/*
* Save exception specific context: ESR and ELR, for all exception levels.
* This is the second part of the shared routine called into from all entries.
*/
_save_el_regs:
/* Could be running at EL3/EL2/EL1 */
switch_el x11, 3f, 2f, 1f
3: mrs x1, esr_el3
mrs x2, elr_el3
b 0f
2: mrs x1, esr_el2
mrs x2, elr_el2
b 0f
1: mrs x1, esr_el1
mrs x2, elr_el1
0:
stp x2, x0, [sp, #-16]!
mov x0, sp
ret
.align 7 /* Current EL FIQ Thread */
stp x29, x30, [sp, #-16]!
bl _exception_entry
bl do_bad_fiq
/* falling through to _exception_exit */
/*
* Restore the exception return address, for all exception levels.
* This is the first part of the shared routine called into from all entries.
*/
exception_exit:
ldp x2, x0, [sp],#16
switch_el x11, 3f, 2f, 1f
3: msr elr_el3, x2
b _restore_regs
2: msr elr_el2, x2
b _restore_regs
1: msr elr_el1, x2
b _restore_regs /* jump to the second part */
.align 7 /* Current EL Error Thread */
stp x29, x30, [sp, #-16]!
bl _exception_entry
bl do_bad_error
b exception_exit
/*
* Restore the general purpose registers from the exception stack, then return.
* This is the second part of the shared routine called into from all entries.
*/
_restore_regs:
ldp x1, x2, [sp],#16
ldp x3, x4, [sp],#16
ldp x5, x6, [sp],#16
ldp x7, x8, [sp],#16
ldp x9, x10, [sp],#16
ldp x11, x12, [sp],#16
ldp x13, x14, [sp],#16
ldp x15, x16, [sp],#16
ldp x17, x18, [sp],#16
ldp x19, x20, [sp],#16
ldp x21, x22, [sp],#16
ldp x23, x24, [sp],#16
ldp x25, x26, [sp],#16
ldp x27, x28, [sp],#16
ldp x29, x30, [sp],#16
eret
.align 7 /* Current EL (SP_ELx) Synchronous Handler */
stp x29, x30, [sp, #-16]!
bl _exception_entry
bl do_sync
b exception_exit
.align 7 /* Current EL (SP_ELx) IRQ Handler */
stp x29, x30, [sp, #-16]!
bl _exception_entry
bl do_irq
b exception_exit
.align 7 /* Current EL (SP_ELx) FIQ Handler */
stp x29, x30, [sp, #-16]!
bl _exception_entry
bl do_fiq
b exception_exit
.align 7 /* Current EL (SP_ELx) Error Handler */
stp x29, x30, [sp, #-16]!
bl _exception_entry
bl do_error
b exception_exit
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