LXR linux/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
  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