| b.liu | e958203 | 2025-04-17 19:18:16 +0800 | [diff] [blame^] | 1 | // SPDX-License-Identifier: GPL-2.0-only |
| 2 | /* |
| 3 | * Copyright 2008 IBM Corp. |
| 4 | * |
| 5 | * Based on arch/powerpc/platforms/pasemi/idle.c: |
| 6 | * Copyright (C) 2006-2007 PA Semi, Inc |
| 7 | * |
| 8 | * Added by: Jerone Young <jyoung5@us.ibm.com> |
| 9 | */ |
| 10 | |
| 11 | #include <linux/of.h> |
| 12 | #include <linux/kernel.h> |
| 13 | #include <asm/machdep.h> |
| 14 | |
| 15 | static int mode_spin; |
| 16 | |
| 17 | static void ppc44x_idle(void) |
| 18 | { |
| 19 | unsigned long msr_save; |
| 20 | |
| 21 | msr_save = mfmsr(); |
| 22 | /* set wait state MSR */ |
| 23 | mtmsr(msr_save|MSR_WE|MSR_EE|MSR_CE|MSR_DE); |
| 24 | isync(); |
| 25 | /* return to initial state */ |
| 26 | mtmsr(msr_save); |
| 27 | isync(); |
| 28 | } |
| 29 | |
| 30 | int __init ppc44x_idle_init(void) |
| 31 | { |
| 32 | if (!mode_spin) { |
| 33 | /* If we are not setting spin mode |
| 34 | then we set to wait mode */ |
| 35 | ppc_md.power_save = &ppc44x_idle; |
| 36 | } |
| 37 | |
| 38 | return 0; |
| 39 | } |
| 40 | |
| 41 | arch_initcall(ppc44x_idle_init); |
| 42 | |
| 43 | static int __init idle_param(char *p) |
| 44 | { |
| 45 | |
| 46 | if (!strcmp("spin", p)) { |
| 47 | mode_spin = 1; |
| 48 | ppc_md.power_save = NULL; |
| 49 | } |
| 50 | |
| 51 | return 0; |
| 52 | } |
| 53 | |
| 54 | early_param("idle", idle_param); |