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
cp6_trap(struct pt_regs * regs,unsigned int instr)23 static 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 */
40 static 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
iop_init_cp6_handler(void)48 void __init iop_init_cp6_handler(void)
49 {
50 register_undef_hook(&cp6_hook);
51 }
52