microblaze: Move cache macro from cache.h to cacheflush.h
[linux-3.10.git] / arch / microblaze / kernel / process.c
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 #include <asm/cacheflush.h>
19
20 void show_regs(struct pt_regs *regs)
21 {
22         printk(KERN_INFO " Registers dump: mode=%X\r\n", regs->pt_mode);
23         printk(KERN_INFO " r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n",
24                                 regs->r1, regs->r2, regs->r3, regs->r4);
25         printk(KERN_INFO " r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n",
26                                 regs->r5, regs->r6, regs->r7, regs->r8);
27         printk(KERN_INFO " r9=%08lX, r10=%08lX, r11=%08lX, r12=%08lX\n",
28                                 regs->r9, regs->r10, regs->r11, regs->r12);
29         printk(KERN_INFO " r13=%08lX, r14=%08lX, r15=%08lX, r16=%08lX\n",
30                                 regs->r13, regs->r14, regs->r15, regs->r16);
31         printk(KERN_INFO " r17=%08lX, r18=%08lX, r19=%08lX, r20=%08lX\n",
32                                 regs->r17, regs->r18, regs->r19, regs->r20);
33         printk(KERN_INFO " r21=%08lX, r22=%08lX, r23=%08lX, r24=%08lX\n",
34                                 regs->r21, regs->r22, regs->r23, regs->r24);
35         printk(KERN_INFO " r25=%08lX, r26=%08lX, r27=%08lX, r28=%08lX\n",
36                                 regs->r25, regs->r26, regs->r27, regs->r28);
37         printk(KERN_INFO " r29=%08lX, r30=%08lX, r31=%08lX, rPC=%08lX\n",
38                                 regs->r29, regs->r30, regs->r31, regs->pc);
39         printk(KERN_INFO " msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n",
40                                 regs->msr, regs->ear, regs->esr, regs->fsr);
41 }
42
43 void (*pm_idle)(void);
44 void (*pm_power_off)(void) = NULL;
45 EXPORT_SYMBOL(pm_power_off);
46
47 static int hlt_counter = 1;
48
49 void disable_hlt(void)
50 {
51         hlt_counter++;
52 }
53 EXPORT_SYMBOL(disable_hlt);
54
55 void enable_hlt(void)
56 {
57         hlt_counter--;
58 }
59 EXPORT_SYMBOL(enable_hlt);
60
61 static int __init nohlt_setup(char *__unused)
62 {
63         hlt_counter = 1;
64         return 1;
65 }
66 __setup("nohlt", nohlt_setup);
67
68 static int __init hlt_setup(char *__unused)
69 {
70         hlt_counter = 0;
71         return 1;
72 }
73 __setup("hlt", hlt_setup);
74
75 void default_idle(void)
76 {
77         if (!hlt_counter) {
78                 clear_thread_flag(TIF_POLLING_NRFLAG);
79                 smp_mb__after_clear_bit();
80                 local_irq_disable();
81                 while (!need_resched())
82                         cpu_sleep();
83                 local_irq_enable();
84                 set_thread_flag(TIF_POLLING_NRFLAG);
85         } else
86                 while (!need_resched())
87                         cpu_relax();
88 }
89
90 void cpu_idle(void)
91 {
92         set_thread_flag(TIF_POLLING_NRFLAG);
93
94         /* endless idle loop with no priority at all */
95         while (1) {
96                 void (*idle)(void) = pm_idle;
97
98                 if (!idle)
99                         idle = default_idle;
100
101                 tick_nohz_stop_sched_tick(1);
102                 while (!need_resched())
103                         idle();
104                 tick_nohz_restart_sched_tick();
105
106                 preempt_enable_no_resched();
107                 schedule();
108                 preempt_disable();
109                 check_pgt_cache();
110         }
111 }
112
113 void flush_thread(void)
114 {
115 }
116
117 int copy_thread(unsigned long clone_flags, unsigned long usp,
118                 unsigned long unused,
119                 struct task_struct *p, struct pt_regs *regs)
120 {
121         struct pt_regs *childregs = task_pt_regs(p);
122         struct thread_info *ti = task_thread_info(p);
123
124         *childregs = *regs;
125         if (user_mode(regs))
126                 childregs->r1 = usp;
127         else
128                 childregs->r1 = ((unsigned long) ti) + THREAD_SIZE;
129
130 #ifndef CONFIG_MMU
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 #else
135
136         /* if creating a kernel thread then update the current reg (we don't
137          * want to use the parent's value when restoring by POP_STATE) */
138         if (kernel_mode(regs))
139                 /* save new current on stack to use POP_STATE */
140                 childregs->CURRENT_TASK = (unsigned long)p;
141         /* if returning to user then use the parent's value of this register */
142
143         /* if we're creating a new kernel thread then just zeroing all
144          * the registers. That's OK for a brand new thread.*/
145         /* Pls. note that some of them will be restored in POP_STATE */
146         if (kernel_mode(regs))
147                 memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
148         /* if this thread is created for fork/vfork/clone, then we want to
149          * restore all the parent's context */
150         /* in addition to the registers which will be restored by POP_STATE */
151         else {
152                 ti->cpu_context = *(struct cpu_context *)regs;
153                 childregs->msr |= MSR_UMS;
154         }
155
156         /* FIXME STATE_SAVE_PT_OFFSET; */
157         ti->cpu_context.r1  = (unsigned long)childregs - STATE_SAVE_ARG_SPACE;
158         /* we should consider the fact that childregs is a copy of the parent
159          * regs which were saved immediately after entering the kernel state
160          * before enabling VM. This MSR will be restored in switch_to and
161          * RETURN() and we want to have the right machine state there
162          * specifically this state must have INTs disabled before and enabled
163          * after performing rtbd
164          * compose the right MSR for RETURN(). It will work for switch_to also
165          * excepting for VM and UMS
166          * don't touch UMS , CARRY and cache bits
167          * right now MSR is a copy of parent one */
168         childregs->msr |= MSR_BIP;
169         childregs->msr &= ~MSR_EIP;
170         childregs->msr |= MSR_IE;
171         childregs->msr &= ~MSR_VM;
172         childregs->msr |= MSR_VMS;
173         childregs->msr |= MSR_EE; /* exceptions will be enabled*/
174
175         ti->cpu_context.msr = (childregs->msr|MSR_VM);
176         ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
177 #endif
178         ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;
179
180         if (clone_flags & CLONE_SETTLS)
181                 ;
182
183         return 0;
184 }
185
186 #ifndef CONFIG_MMU
187 /*
188  * Return saved PC of a blocked thread.
189  */
190 unsigned long thread_saved_pc(struct task_struct *tsk)
191 {
192         struct cpu_context *ctx =
193                 &(((struct thread_info *)(tsk->stack))->cpu_context);
194
195         /* Check whether the thread is blocked in resume() */
196         if (in_sched_functions(ctx->r15))
197                 return (unsigned long)ctx->r15;
198         else
199                 return ctx->r14;
200 }
201 #endif
202
203 static void kernel_thread_helper(int (*fn)(void *), void *arg)
204 {
205         fn(arg);
206         do_exit(-1);
207 }
208
209 int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
210 {
211         struct pt_regs regs;
212
213         memset(&regs, 0, sizeof(regs));
214         /* store them in non-volatile registers */
215         regs.r5 = (unsigned long)fn;
216         regs.r6 = (unsigned long)arg;
217         local_save_flags(regs.msr);
218         regs.pc = (unsigned long)kernel_thread_helper;
219         regs.pt_mode = 1;
220
221         return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
222                         &regs, 0, NULL, NULL);
223 }
224 EXPORT_SYMBOL_GPL(kernel_thread);
225
226 unsigned long get_wchan(struct task_struct *p)
227 {
228 /* TBD (used by procfs) */
229         return 0;
230 }
231
232 /* Set up a thread for executing a new program */
233 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
234 {
235         set_fs(USER_DS);
236         regs->pc = pc;
237         regs->r1 = usp;
238         regs->pt_mode = 0;
239 #ifdef CONFIG_MMU
240         regs->msr |= MSR_UMS;
241 #endif
242 }
243
244 #ifdef CONFIG_MMU
245 #include <linux/elfcore.h>
246 /*
247  * Set up a thread for executing a new program
248  */
249 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
250 {
251         return 0; /* MicroBlaze has no separate FPU registers */
252 }
253 #endif /* CONFIG_MMU */