1/*
2 * IOP Coprocessor-6 access handler
3 * Copyright (c) 2006, Intel Corporation.
4 *
5 * This program is free software; you can redistribute it and/or modify it
6 * under the terms and conditions of the GNU General Public License,
7 * version 2, as published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
12 * more details.
13 *
14 * You should have received a copy of the GNU General Public License along with
15 * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
16 * Place - Suite 330, Boston, MA 02111-1307 USA.
17 *
18 */
19#include <linux/init.h>
20#include <asm/traps.h>
21#include <asm/ptrace.h>
22
23static int cp6_trap(struct pt_regs *regs, unsigned int instr)
24{
25	u32 temp;
26
27        /* enable cp6 access */
28        asm volatile (
29		"mrc	p15, 0, %0, c15, c1, 0\n\t"
30		"orr	%0, %0, #(1 << 6)\n\t"
31		"mcr	p15, 0, %0, c15, c1, 0\n\t"
32		: "=r"(temp));
33
34	return 0;
35}
36
37/* permit kernel space cp6 access
38 * deny user space cp6 access
39 */
40static struct undef_hook cp6_hook = {
41	.instr_mask     = 0x0f000ff0,
42	.instr_val      = 0x0e000610,
43	.cpsr_mask      = MODE_MASK,
44	.cpsr_val       = SVC_MODE,
45	.fn             = cp6_trap,
46};
47
48void __init iop_init_cp6_handler(void)
49{
50	register_undef_hook(&cp6_hook);
51}
52