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 early_init_dt_scan_epapr(unsigned long node,
  34                                           const char *uname,
  35                                           int depth, void *data)
  36{
  37        const u32 *insts;
  38        unsigned long len;
  39        int i;
  40
  41        insts = of_get_flat_dt_prop(node, "hcall-instructions", &len);
  42        if (!insts)
  43                return 0;
  44
  45        if (len % 4 || len > (4 * 4))
  46                return -1;
  47
  48        for (i = 0; i < (len / 4); i++) {
  49                patch_instruction(epapr_hypercall_start + i, insts[i]);
  50#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
  51                patch_instruction(epapr_ev_idle_start + i, insts[i]);
  52#endif
  53        }
  54
  55#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
  56        if (of_get_flat_dt_prop(node, "has-idle", NULL))
  57                ppc_md.power_save = epapr_ev_idle;
  58#endif
  59
  60        epapr_paravirt_enabled = true;
  61
  62        return 1;
  63}
  64
  65int __init epapr_paravirt_early_init(void)
  66{
  67        of_scan_flat_dt(early_init_dt_scan_epapr, NULL);
  68
  69        return 0;
  70}
  71
  72