LXR linux/arch/powerpc/kernel/epapr

   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 * ePAPR para-virtualization support.
   4 *
   5 * Copyright (C) 2012 Freescale Semiconductor, Inc.
   6 */
   7
   8#include <linux/of.h>
   9#include <linux/of_fdt.h>
  10#include <asm/epapr_hcalls.h>
  11#include <asm/cacheflush.h>
  12#include <asm/code-patching.h>
  13#include <asm/machdep.h>
  14
  15#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
  16extern void epapr_ev_idle(void);
  17extern u32 epapr_ev_idle_start[];
  18#endif
  19
  20bool epapr_paravirt_enabled;
  21static bool __maybe_unused epapr_has_idle;
  22
  23static int __init early_init_dt_scan_epapr(unsigned long node,
  24                                           const char *uname,
  25                                           int depth, void *data)
  26{
  27        const u32 *insts;
  28        int len;
  29        int i;
  30
  31        insts = of_get_flat_dt_prop(node, "hcall-instructions", &len);
  32        if (!insts)
  33                return 0;
  34
  35        if (len % 4 || len > (4 * 4))
  36                return -1;
  37
  38        for (i = 0; i < (len / 4); i++) {
  39                u32 inst = be32_to_cpu(insts[i]);
  40                patch_instruction(epapr_hypercall_start + i, inst);
  41#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
  42                patch_instruction(epapr_ev_idle_start + i, inst);
  43#endif
  44        }
  45
  46#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
  47        if (of_get_flat_dt_prop(node, "has-idle", NULL))
  48                epapr_has_idle = true;
  49#endif
  50
  51        epapr_paravirt_enabled = true;
  52
  53        return 1;
  54}
  55
  56int __init epapr_paravirt_early_init(void)
  57{
  58        of_scan_flat_dt(early_init_dt_scan_epapr, NULL);
  59
  60        return 0;
  61}
  62
  63static int __init epapr_idle_init(void)
  64{
  65#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
  66        if (epapr_has_idle)
  67                ppc_md.power_save = epapr_ev_idle;
  68#endif
  69
  70        return 0;
  71}
  72
  73postcore_initcall(epapr_idle_init);
  74