1 /* 2 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu> 3 * Copyright (C) 2008-2009 PetaLogix 4 * Copyright (C) 2006 Atmark Techno, Inc. 5 * 6 * This file is subject to the terms and conditions of the GNU General Public 7 * License. See the file "COPYING" in the main directory of this archive 8 * for more details. 9 */ 10 11 #include <linux/module.h> 12 #include <linux/sched.h> 13 #include <linux/pm.h> 14 #include <linux/tick.h> 15 #include <linux/bitops.h> 16 #include <asm/system.h> 17 #include <asm/pgalloc.h> 18 19 void show_regs(struct pt_regs *regs) 20 { 21 printk(KERN_INFO " Registers dump: mode=%X\r\n", regs->kernel_mode); 22 printk(KERN_INFO " r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n", 23 regs->r1, regs->r2, regs->r3, regs->r4); 24 printk(KERN_INFO " r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n", 25 regs->r5, regs->r6, regs->r7, regs->r8); 26 printk(KERN_INFO " r9=%08lX, r10=%08lX, r11=%08lX, r12=%08lX\n", 27 regs->r9, regs->r10, regs->r11, regs->r12); 28 printk(KERN_INFO " r13=%08lX, r14=%08lX, r15=%08lX, r16=%08lX\n", 29 regs->r13, regs->r14, regs->r15, regs->r16); 30 printk(KERN_INFO " r17=%08lX, r18=%08lX, r19=%08lX, r20=%08lX\n", 31 regs->r17, regs->r18, regs->r19, regs->r20); 32 printk(KERN_INFO " r21=%08lX, r22=%08lX, r23=%08lX, r24=%08lX\n", 33 regs->r21, regs->r22, regs->r23, regs->r24); 34 printk(KERN_INFO " r25=%08lX, r26=%08lX, r27=%08lX, r28=%08lX\n", 35 regs->r25, regs->r26, regs->r27, regs->r28); 36 printk(KERN_INFO " r29=%08lX, r30=%08lX, r31=%08lX, rPC=%08lX\n", 37 regs->r29, regs->r30, regs->r31, regs->pc); 38 printk(KERN_INFO " msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n", 39 regs->msr, regs->ear, regs->esr, regs->fsr); 40 while (1) 41 ; 42 } 43 44 void (*pm_idle)(void); 45 void (*pm_power_off)(void) = NULL; 46 EXPORT_SYMBOL(pm_power_off); 47 48 static int hlt_counter = 1; 49 50 void disable_hlt(void) 51 { 52 hlt_counter++; 53 } 54 EXPORT_SYMBOL(disable_hlt); 55 56 void enable_hlt(void) 57 { 58 hlt_counter--; 59 } 60 EXPORT_SYMBOL(enable_hlt); 61 62 static int __init nohlt_setup(char *__unused) 63 { 64 hlt_counter = 1; 65 return 1; 66 } 67 __setup("nohlt", nohlt_setup); 68 69 static int __init hlt_setup(char *__unused) 70 { 71 hlt_counter = 0; 72 return 1; 73 } 74 __setup("hlt", hlt_setup); 75 76 void default_idle(void) 77 { 78 if (!hlt_counter) { 79 clear_thread_flag(TIF_POLLING_NRFLAG); 80 smp_mb__after_clear_bit(); 81 local_irq_disable(); 82 while (!need_resched()) 83 cpu_sleep(); 84 local_irq_enable(); 85 set_thread_flag(TIF_POLLING_NRFLAG); 86 } else 87 while (!need_resched()) 88 cpu_relax(); 89 } 90 91 void cpu_idle(void) 92 { 93 set_thread_flag(TIF_POLLING_NRFLAG); 94 95 /* endless idle loop with no priority at all */ 96 while (1) { 97 void (*idle)(void) = pm_idle; 98 99 if (!idle) 100 idle = default_idle; 101 102 tick_nohz_stop_sched_tick(1); 103 while (!need_resched()) 104 idle(); 105 tick_nohz_restart_sched_tick(); 106 107 preempt_enable_no_resched(); 108 schedule(); 109 preempt_disable(); 110 check_pgt_cache(); 111 } 112 } 113 114 void flush_thread(void) 115 { 116 } 117 118 int copy_thread(unsigned long clone_flags, unsigned long usp, 119 unsigned long unused, 120 struct task_struct *p, struct pt_regs *regs) 121 { 122 struct pt_regs *childregs = task_pt_regs(p); 123 struct thread_info *ti = task_thread_info(p); 124 125 *childregs = *regs; 126 if (user_mode(regs)) 127 childregs->r1 = usp; 128 else 129 childregs->r1 = ((unsigned long) ti) + THREAD_SIZE; 130 131 memset(&ti->cpu_context, 0, sizeof(struct cpu_context)); 132 ti->cpu_context.r1 = (unsigned long)childregs; 133 ti->cpu_context.msr = (unsigned long)childregs->msr; 134 ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8; 135 136 if (clone_flags & CLONE_SETTLS) 137 ; 138 139 return 0; 140 } 141 142 /* 143 * Return saved PC of a blocked thread. 144 */ 145 unsigned long thread_saved_pc(struct task_struct *tsk) 146 { 147 struct cpu_context *ctx = 148 &(((struct thread_info *)(tsk->stack))->cpu_context); 149 150 /* Check whether the thread is blocked in resume() */ 151 if (in_sched_functions(ctx->r15)) 152 return (unsigned long)ctx->r15; 153 else 154 return ctx->r14; 155 } 156 157 static void kernel_thread_helper(int (*fn)(void *), void *arg) 158 { 159 fn(arg); 160 do_exit(-1); 161 } 162 163 int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) 164 { 165 struct pt_regs regs; 166 int ret; 167 168 memset(®s, 0, sizeof(regs)); 169 /* store them in non-volatile registers */ 170 regs.r5 = (unsigned long)fn; 171 regs.r6 = (unsigned long)arg; 172 local_save_flags(regs.msr); 173 regs.pc = (unsigned long)kernel_thread_helper; 174 regs.kernel_mode = 1; 175 176 ret = do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, 177 ®s, 0, NULL, NULL); 178 179 return ret; 180 } 181 182 unsigned long get_wchan(struct task_struct *p) 183 { 184 /* TBD (used by procfs) */ 185 return 0; 186 } 187