arch/arm/plat-iop/cp6.c

   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
  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
  48 void __init iop_init_cp6_handler(void)
  49 {
  50         register_undef_hook(&cp6_hook);
  51 }