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6496a23a MS |
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> | |
40db0834 | 18 | #include <asm/uaccess.h> /* for USER_DS macros */ |
a1f55113 | 19 | #include <asm/cacheflush.h> |
6496a23a MS |
20 | |
21 | void show_regs(struct pt_regs *regs) | |
22 | { | |
ac3efab5 | 23 | printk(KERN_INFO " Registers dump: mode=%X\r\n", regs->pt_mode); |
6496a23a MS |
24 | printk(KERN_INFO " r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n", |
25 | regs->r1, regs->r2, regs->r3, regs->r4); | |
26 | printk(KERN_INFO " r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n", | |
27 | regs->r5, regs->r6, regs->r7, regs->r8); | |
28 | printk(KERN_INFO " r9=%08lX, r10=%08lX, r11=%08lX, r12=%08lX\n", | |
29 | regs->r9, regs->r10, regs->r11, regs->r12); | |
30 | printk(KERN_INFO " r13=%08lX, r14=%08lX, r15=%08lX, r16=%08lX\n", | |
31 | regs->r13, regs->r14, regs->r15, regs->r16); | |
32 | printk(KERN_INFO " r17=%08lX, r18=%08lX, r19=%08lX, r20=%08lX\n", | |
33 | regs->r17, regs->r18, regs->r19, regs->r20); | |
34 | printk(KERN_INFO " r21=%08lX, r22=%08lX, r23=%08lX, r24=%08lX\n", | |
35 | regs->r21, regs->r22, regs->r23, regs->r24); | |
36 | printk(KERN_INFO " r25=%08lX, r26=%08lX, r27=%08lX, r28=%08lX\n", | |
37 | regs->r25, regs->r26, regs->r27, regs->r28); | |
38 | printk(KERN_INFO " r29=%08lX, r30=%08lX, r31=%08lX, rPC=%08lX\n", | |
39 | regs->r29, regs->r30, regs->r31, regs->pc); | |
40 | printk(KERN_INFO " msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n", | |
41 | regs->msr, regs->ear, regs->esr, regs->fsr); | |
6496a23a MS |
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 | { | |
78ebfa88 MS |
78 | if (likely(hlt_counter)) { |
79 | while (!need_resched()) | |
80 | cpu_relax(); | |
81 | } else { | |
6496a23a MS |
82 | clear_thread_flag(TIF_POLLING_NRFLAG); |
83 | smp_mb__after_clear_bit(); | |
84 | local_irq_disable(); | |
85 | while (!need_resched()) | |
86 | cpu_sleep(); | |
87 | local_irq_enable(); | |
88 | set_thread_flag(TIF_POLLING_NRFLAG); | |
78ebfa88 | 89 | } |
6496a23a MS |
90 | } |
91 | ||
92 | void cpu_idle(void) | |
93 | { | |
94 | set_thread_flag(TIF_POLLING_NRFLAG); | |
95 | ||
96 | /* endless idle loop with no priority at all */ | |
97 | while (1) { | |
98 | void (*idle)(void) = pm_idle; | |
99 | ||
100 | if (!idle) | |
101 | idle = default_idle; | |
102 | ||
103 | tick_nohz_stop_sched_tick(1); | |
104 | while (!need_resched()) | |
105 | idle(); | |
106 | tick_nohz_restart_sched_tick(); | |
107 | ||
108 | preempt_enable_no_resched(); | |
109 | schedule(); | |
110 | preempt_disable(); | |
111 | check_pgt_cache(); | |
112 | } | |
113 | } | |
114 | ||
115 | void flush_thread(void) | |
116 | { | |
117 | } | |
118 | ||
a8fb748e | 119 | int copy_thread(unsigned long clone_flags, unsigned long usp, |
6496a23a MS |
120 | unsigned long unused, |
121 | struct task_struct *p, struct pt_regs *regs) | |
122 | { | |
123 | struct pt_regs *childregs = task_pt_regs(p); | |
124 | struct thread_info *ti = task_thread_info(p); | |
125 | ||
126 | *childregs = *regs; | |
127 | if (user_mode(regs)) | |
128 | childregs->r1 = usp; | |
129 | else | |
130 | childregs->r1 = ((unsigned long) ti) + THREAD_SIZE; | |
131 | ||
5233806d | 132 | #ifndef CONFIG_MMU |
6496a23a MS |
133 | memset(&ti->cpu_context, 0, sizeof(struct cpu_context)); |
134 | ti->cpu_context.r1 = (unsigned long)childregs; | |
135 | ti->cpu_context.msr = (unsigned long)childregs->msr; | |
5233806d MS |
136 | #else |
137 | ||
138 | /* if creating a kernel thread then update the current reg (we don't | |
139 | * want to use the parent's value when restoring by POP_STATE) */ | |
140 | if (kernel_mode(regs)) | |
141 | /* save new current on stack to use POP_STATE */ | |
142 | childregs->CURRENT_TASK = (unsigned long)p; | |
143 | /* if returning to user then use the parent's value of this register */ | |
144 | ||
145 | /* if we're creating a new kernel thread then just zeroing all | |
146 | * the registers. That's OK for a brand new thread.*/ | |
147 | /* Pls. note that some of them will be restored in POP_STATE */ | |
148 | if (kernel_mode(regs)) | |
149 | memset(&ti->cpu_context, 0, sizeof(struct cpu_context)); | |
150 | /* if this thread is created for fork/vfork/clone, then we want to | |
151 | * restore all the parent's context */ | |
152 | /* in addition to the registers which will be restored by POP_STATE */ | |
153 | else { | |
154 | ti->cpu_context = *(struct cpu_context *)regs; | |
155 | childregs->msr |= MSR_UMS; | |
156 | } | |
157 | ||
158 | /* FIXME STATE_SAVE_PT_OFFSET; */ | |
159 | ti->cpu_context.r1 = (unsigned long)childregs - STATE_SAVE_ARG_SPACE; | |
160 | /* we should consider the fact that childregs is a copy of the parent | |
161 | * regs which were saved immediately after entering the kernel state | |
162 | * before enabling VM. This MSR will be restored in switch_to and | |
163 | * RETURN() and we want to have the right machine state there | |
164 | * specifically this state must have INTs disabled before and enabled | |
165 | * after performing rtbd | |
166 | * compose the right MSR for RETURN(). It will work for switch_to also | |
167 | * excepting for VM and UMS | |
168 | * don't touch UMS , CARRY and cache bits | |
169 | * right now MSR is a copy of parent one */ | |
170 | childregs->msr |= MSR_BIP; | |
171 | childregs->msr &= ~MSR_EIP; | |
172 | childregs->msr |= MSR_IE; | |
173 | childregs->msr &= ~MSR_VM; | |
174 | childregs->msr |= MSR_VMS; | |
175 | childregs->msr |= MSR_EE; /* exceptions will be enabled*/ | |
176 | ||
177 | ti->cpu_context.msr = (childregs->msr|MSR_VM); | |
178 | ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */ | |
179 | #endif | |
6496a23a MS |
180 | ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8; |
181 | ||
182 | if (clone_flags & CLONE_SETTLS) | |
183 | ; | |
184 | ||
185 | return 0; | |
186 | } | |
187 | ||
5233806d | 188 | #ifndef CONFIG_MMU |
6496a23a MS |
189 | /* |
190 | * Return saved PC of a blocked thread. | |
191 | */ | |
192 | unsigned long thread_saved_pc(struct task_struct *tsk) | |
193 | { | |
194 | struct cpu_context *ctx = | |
195 | &(((struct thread_info *)(tsk->stack))->cpu_context); | |
196 | ||
197 | /* Check whether the thread is blocked in resume() */ | |
198 | if (in_sched_functions(ctx->r15)) | |
199 | return (unsigned long)ctx->r15; | |
200 | else | |
201 | return ctx->r14; | |
202 | } | |
5233806d | 203 | #endif |
6496a23a MS |
204 | |
205 | static void kernel_thread_helper(int (*fn)(void *), void *arg) | |
206 | { | |
207 | fn(arg); | |
208 | do_exit(-1); | |
209 | } | |
210 | ||
211 | int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags) | |
212 | { | |
213 | struct pt_regs regs; | |
6496a23a MS |
214 | |
215 | memset(®s, 0, sizeof(regs)); | |
216 | /* store them in non-volatile registers */ | |
217 | regs.r5 = (unsigned long)fn; | |
218 | regs.r6 = (unsigned long)arg; | |
219 | local_save_flags(regs.msr); | |
220 | regs.pc = (unsigned long)kernel_thread_helper; | |
ac3efab5 | 221 | regs.pt_mode = 1; |
6496a23a | 222 | |
6714fcc3 | 223 | return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0, |
6496a23a | 224 | ®s, 0, NULL, NULL); |
6496a23a | 225 | } |
5af7fa68 | 226 | EXPORT_SYMBOL_GPL(kernel_thread); |
6496a23a MS |
227 | |
228 | unsigned long get_wchan(struct task_struct *p) | |
229 | { | |
230 | /* TBD (used by procfs) */ | |
231 | return 0; | |
232 | } | |
e1c4bd08 MS |
233 | |
234 | /* Set up a thread for executing a new program */ | |
235 | void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp) | |
236 | { | |
237 | set_fs(USER_DS); | |
238 | regs->pc = pc; | |
239 | regs->r1 = usp; | |
240 | regs->pt_mode = 0; | |
f1ae3f69 | 241 | #ifdef CONFIG_MMU |
866d7229 | 242 | regs->msr |= MSR_UMS; |
f1ae3f69 | 243 | #endif |
e1c4bd08 | 244 | } |
5233806d MS |
245 | |
246 | #ifdef CONFIG_MMU | |
247 | #include <linux/elfcore.h> | |
248 | /* | |
249 | * Set up a thread for executing a new program | |
250 | */ | |
251 | int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs) | |
252 | { | |
253 | return 0; /* MicroBlaze has no separate FPU registers */ | |
254 | } | |
255 | #endif /* CONFIG_MMU */ |