kernel_samsung_a34x-permissive/arch/powerpc/kernel/epapr_paravirt.c

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/*
* ePAPR para-virtualization support.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License, version 2, as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*
* Copyright (C) 2012 Freescale Semiconductor, Inc.
*/
#include <linux/of.h>
#include <linux/of_fdt.h>
#include <asm/epapr_hcalls.h>
#include <asm/cacheflush.h>
#include <asm/code-patching.h>
#include <asm/machdep.h>
#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
extern void epapr_ev_idle(void);
extern u32 epapr_ev_idle_start[];
#endif
bool epapr_paravirt_enabled;
static bool __maybe_unused epapr_has_idle;
static int __init early_init_dt_scan_epapr(unsigned long node,
const char *uname,
int depth, void *data)
{
const u32 *insts;
int len;
int i;
insts = of_get_flat_dt_prop(node, "hcall-instructions", &len);
if (!insts)
return 0;
if (len % 4 || len > (4 * 4))
return -1;
for (i = 0; i < (len / 4); i++) {
u32 inst = be32_to_cpu(insts[i]);
patch_instruction(epapr_hypercall_start + i, inst);
#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
patch_instruction(epapr_ev_idle_start + i, inst);
#endif
}
#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
if (of_get_flat_dt_prop(node, "has-idle", NULL))
epapr_has_idle = true;
#endif
epapr_paravirt_enabled = true;
return 1;
}
int __init epapr_paravirt_early_init(void)
{
of_scan_flat_dt(early_init_dt_scan_epapr, NULL);
return 0;
}
static int __init epapr_idle_init(void)
{
#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
if (epapr_has_idle)
ppc_md.power_save = epapr_ev_idle;
#endif
return 0;
}
postcore_initcall(epapr_idle_init);