xref: /OK3568_Linux_fs/kernel/arch/arm/mm/abort-ev4.S (revision 4882a59341e53eb6f0b4789bf948001014eff981)
1*4882a593Smuzhiyun/* SPDX-License-Identifier: GPL-2.0 */
2*4882a593Smuzhiyun#include <linux/linkage.h>
3*4882a593Smuzhiyun#include <asm/assembler.h>
4*4882a593Smuzhiyun/*
5*4882a593Smuzhiyun * Function: v4_early_abort
6*4882a593Smuzhiyun *
7*4882a593Smuzhiyun * Params  : r2 = pt_regs
8*4882a593Smuzhiyun *	   : r4 = aborted context pc
9*4882a593Smuzhiyun *	   : r5 = aborted context psr
10*4882a593Smuzhiyun *
11*4882a593Smuzhiyun * Returns : r4 - r11, r13 preserved
12*4882a593Smuzhiyun *
13*4882a593Smuzhiyun * Purpose : obtain information about current aborted instruction.
14*4882a593Smuzhiyun * Note: we read user space.  This means we might cause a data
15*4882a593Smuzhiyun * abort here if the I-TLB and D-TLB aren't seeing the same
16*4882a593Smuzhiyun * picture.  Unfortunately, this does happen.  We live with it.
17*4882a593Smuzhiyun */
18*4882a593Smuzhiyun	.align	5
19*4882a593SmuzhiyunENTRY(v4_early_abort)
20*4882a593Smuzhiyun	mrc	p15, 0, r1, c5, c0, 0		@ get FSR
21*4882a593Smuzhiyun	mrc	p15, 0, r0, c6, c0, 0		@ get FAR
22*4882a593Smuzhiyun	ldr	r3, [r4]			@ read aborted ARM instruction
23*4882a593Smuzhiyun	uaccess_disable ip			@ disable userspace access
24*4882a593Smuzhiyun	bic	r1, r1, #1 << 11 | 1 << 10	@ clear bits 11 and 10 of FSR
25*4882a593Smuzhiyun	tst	r3, #1 << 20			@ L = 1 -> write?
26*4882a593Smuzhiyun	orreq	r1, r1, #1 << 11		@ yes.
27*4882a593Smuzhiyun	b	do_DataAbort
28