xref: /OK3568_Linux_fs/kernel/arch/arm/mm/abort-ev7.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: v7_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 */
15*4882a593Smuzhiyun	.align	5
16*4882a593SmuzhiyunENTRY(v7_early_abort)
17*4882a593Smuzhiyun	mrc	p15, 0, r1, c5, c0, 0		@ get FSR
18*4882a593Smuzhiyun	mrc	p15, 0, r0, c6, c0, 0		@ get FAR
19*4882a593Smuzhiyun	uaccess_disable ip			@ disable userspace access
20*4882a593Smuzhiyun
21*4882a593Smuzhiyun	/*
22*4882a593Smuzhiyun	 * V6 code adjusts the returned DFSR.
23*4882a593Smuzhiyun	 * New designs should not need to patch up faults.
24*4882a593Smuzhiyun	 */
25*4882a593Smuzhiyun
26*4882a593Smuzhiyun#if defined(CONFIG_VERIFY_PERMISSION_FAULT)
27*4882a593Smuzhiyun	/*
28*4882a593Smuzhiyun	 * Detect erroneous permission failures and fix
29*4882a593Smuzhiyun	 */
30*4882a593Smuzhiyun	ldr	r3, =0x40d			@ On permission fault
31*4882a593Smuzhiyun	and	r3, r1, r3
32*4882a593Smuzhiyun	cmp	r3, #0x0d
33*4882a593Smuzhiyun	bne	do_DataAbort
34*4882a593Smuzhiyun
35*4882a593Smuzhiyun	mcr	p15, 0, r0, c7, c8, 0   	@ Retranslate FAR
36*4882a593Smuzhiyun	isb
37*4882a593Smuzhiyun	mrc	p15, 0, ip, c7, c4, 0   	@ Read the PAR
38*4882a593Smuzhiyun	and	r3, ip, #0x7b   		@ On translation fault
39*4882a593Smuzhiyun	cmp	r3, #0x0b
40*4882a593Smuzhiyun	bne	do_DataAbort
41*4882a593Smuzhiyun	bic	r1, r1, #0xf			@ Fix up FSR FS[5:0]
42*4882a593Smuzhiyun	and	ip, ip, #0x7e
43*4882a593Smuzhiyun	orr	r1, r1, ip, LSR #1
44*4882a593Smuzhiyun#endif
45*4882a593Smuzhiyun
46*4882a593Smuzhiyun	b	do_DataAbort
47*4882a593SmuzhiyunENDPROC(v7_early_abort)
48