tmp_suning_uos_patched/arch/powerpc/kernel/epapr_paravirt.c
Jordan Niethe 94afd069d9 powerpc: Use a datatype for instructions
Currently unsigned ints are used to represent instructions on powerpc.
This has worked well as instructions have always been 4 byte words.

However, ISA v3.1 introduces some changes to instructions that mean
this scheme will no longer work as well. This change is Prefixed
Instructions. A prefixed instruction is made up of a word prefix
followed by a word suffix to make an 8 byte double word instruction.
No matter the endianness of the system the prefix always comes first.
Prefixed instructions are only planned for powerpc64.

Introduce a ppc_inst type to represent both prefixed and word
instructions on powerpc64 while keeping it possible to exclusively
have word instructions on powerpc32.

Signed-off-by: Jordan Niethe <jniethe5@gmail.com>
[mpe: Fix compile error in emulate_spe()]
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Link: https://lore.kernel.org/r/20200506034050.24806-12-jniethe5@gmail.com
2020-05-19 00:10:37 +10:00

75 lines
1.6 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* ePAPR para-virtualization support.
*
* 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>
#include <asm/inst.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++) {
struct ppc_inst inst = ppc_inst(be32_to_cpu(insts[i]));
patch_instruction((struct ppc_inst *)(epapr_hypercall_start + i), inst);
#if !defined(CONFIG_64BIT) || defined(CONFIG_PPC_BOOK3E_64)
patch_instruction((struct ppc_inst *)(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);