LXR linux/arch/powerpc/kernel/epapr

   1/*
   2 * ePAPR para-virtualization support.
   3 *
   4 * This program is free software; you can redistribute it and/or modify
   5 * it under the terms of the GNU General Public License, version 2, as
   6 * published by the Free Software Foundation.
   7 *
   8 * This program is distributed in the hope that it will be useful,
   9 * but WITHOUT ANY WARRANTY; without even the implied warranty of
  10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  11 * GNU General Public License for more details.
  12 *
  13 * You should have received a copy of the GNU General Public License
  14 * along with this program; if not, write to the Free Software
  15 * Foundation, 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
  16 *
  17 * Copyright (C) 2012 Freescale Semiconductor, Inc.
  18 */
  19
  20#include <linux/of.h>
  21#include <asm/epapr_hcalls.h>
  22#include <asm/cacheflush.h>
  23#include <asm/code-patching.h>
  24#include <asm/machdep.h>
  25
  26#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
  27extern void epapr_ev_idle(void);
  28extern u32 epapr_ev_idle_start[];
  29#endif
  30
  31bool epapr_paravirt_enabled;
  32
  33static int __init epapr_paravirt_init(void)
  34{
  35        struct device_node *hyper_node;
  36        const u32 *insts;
  37        int len, i;
  38
  39        hyper_node = of_find_node_by_path("/hypervisor");
  40        if (!hyper_node)
  41                return -ENODEV;
  42
  43        insts = of_get_property(hyper_node, "hcall-instructions", &len);
  44        if (!insts)
  45                return -ENODEV;
  46
  47        if (len % 4 || len > (4 * 4))
  48                return -ENODEV;
  49
  50        for (i = 0; i < (len / 4); i++) {
  51                patch_instruction(epapr_hypercall_start + i, insts[i]);
  52#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
  53                patch_instruction(epapr_ev_idle_start + i, insts[i]);
  54#endif
  55        }
  56
  57#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
  58        if (of_get_property(hyper_node, "has-idle", NULL))
  59                ppc_md.power_save = epapr_ev_idle;
  60#endif
  61
  62        epapr_paravirt_enabled = true;
  63
  64        return 0;
  65}
  66
  67early_initcall(epapr_paravirt_init);
  68