microblaze_mmu_v2: Update process creation for MMU
[linux-2.6/mini2440.git] / arch / microblaze / kernel / process.c
blob00b12c6d5326767fc9260df77801a699050cdee7
1 /*
2 * Copyright (C) 2008-2009 Michal Simek <monstr@monstr.eu>
3 * Copyright (C) 2008-2009 PetaLogix
4 * Copyright (C) 2006 Atmark Techno, Inc.
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 */
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>
19 void show_regs(struct pt_regs *regs)
21 printk(KERN_INFO " Registers dump: mode=%X\r\n", regs->pt_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);
42 void (*pm_idle)(void);
43 void (*pm_power_off)(void) = NULL;
44 EXPORT_SYMBOL(pm_power_off);
46 static int hlt_counter = 1;
48 void disable_hlt(void)
50 hlt_counter++;
52 EXPORT_SYMBOL(disable_hlt);
54 void enable_hlt(void)
56 hlt_counter--;
58 EXPORT_SYMBOL(enable_hlt);
60 static int __init nohlt_setup(char *__unused)
62 hlt_counter = 1;
63 return 1;
65 __setup("nohlt", nohlt_setup);
67 static int __init hlt_setup(char *__unused)
69 hlt_counter = 0;
70 return 1;
72 __setup("hlt", hlt_setup);
74 void default_idle(void)
76 if (!hlt_counter) {
77 clear_thread_flag(TIF_POLLING_NRFLAG);
78 smp_mb__after_clear_bit();
79 local_irq_disable();
80 while (!need_resched())
81 cpu_sleep();
82 local_irq_enable();
83 set_thread_flag(TIF_POLLING_NRFLAG);
84 } else
85 while (!need_resched())
86 cpu_relax();
89 void cpu_idle(void)
91 set_thread_flag(TIF_POLLING_NRFLAG);
93 /* endless idle loop with no priority at all */
94 while (1) {
95 void (*idle)(void) = pm_idle;
97 if (!idle)
98 idle = default_idle;
100 tick_nohz_stop_sched_tick(1);
101 while (!need_resched())
102 idle();
103 tick_nohz_restart_sched_tick();
105 preempt_enable_no_resched();
106 schedule();
107 preempt_disable();
108 check_pgt_cache();
112 void flush_thread(void)
116 int copy_thread(unsigned long clone_flags, unsigned long usp,
117 unsigned long unused,
118 struct task_struct *p, struct pt_regs *regs)
120 struct pt_regs *childregs = task_pt_regs(p);
121 struct thread_info *ti = task_thread_info(p);
123 *childregs = *regs;
124 if (user_mode(regs))
125 childregs->r1 = usp;
126 else
127 childregs->r1 = ((unsigned long) ti) + THREAD_SIZE;
129 #ifndef CONFIG_MMU
130 memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
131 ti->cpu_context.r1 = (unsigned long)childregs;
132 ti->cpu_context.msr = (unsigned long)childregs->msr;
133 #else
135 /* if creating a kernel thread then update the current reg (we don't
136 * want to use the parent's value when restoring by POP_STATE) */
137 if (kernel_mode(regs))
138 /* save new current on stack to use POP_STATE */
139 childregs->CURRENT_TASK = (unsigned long)p;
140 /* if returning to user then use the parent's value of this register */
142 /* if we're creating a new kernel thread then just zeroing all
143 * the registers. That's OK for a brand new thread.*/
144 /* Pls. note that some of them will be restored in POP_STATE */
145 if (kernel_mode(regs))
146 memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
147 /* if this thread is created for fork/vfork/clone, then we want to
148 * restore all the parent's context */
149 /* in addition to the registers which will be restored by POP_STATE */
150 else {
151 ti->cpu_context = *(struct cpu_context *)regs;
152 childregs->msr |= MSR_UMS;
155 /* FIXME STATE_SAVE_PT_OFFSET; */
156 ti->cpu_context.r1 = (unsigned long)childregs - STATE_SAVE_ARG_SPACE;
157 /* we should consider the fact that childregs is a copy of the parent
158 * regs which were saved immediately after entering the kernel state
159 * before enabling VM. This MSR will be restored in switch_to and
160 * RETURN() and we want to have the right machine state there
161 * specifically this state must have INTs disabled before and enabled
162 * after performing rtbd
163 * compose the right MSR for RETURN(). It will work for switch_to also
164 * excepting for VM and UMS
165 * don't touch UMS , CARRY and cache bits
166 * right now MSR is a copy of parent one */
167 childregs->msr |= MSR_BIP;
168 childregs->msr &= ~MSR_EIP;
169 childregs->msr |= MSR_IE;
170 childregs->msr &= ~MSR_VM;
171 childregs->msr |= MSR_VMS;
172 childregs->msr |= MSR_EE; /* exceptions will be enabled*/
174 ti->cpu_context.msr = (childregs->msr|MSR_VM);
175 ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
176 #endif
177 ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;
179 if (clone_flags & CLONE_SETTLS)
182 return 0;
185 #ifndef CONFIG_MMU
187 * Return saved PC of a blocked thread.
189 unsigned long thread_saved_pc(struct task_struct *tsk)
191 struct cpu_context *ctx =
192 &(((struct thread_info *)(tsk->stack))->cpu_context);
194 /* Check whether the thread is blocked in resume() */
195 if (in_sched_functions(ctx->r15))
196 return (unsigned long)ctx->r15;
197 else
198 return ctx->r14;
200 #endif
202 static void kernel_thread_helper(int (*fn)(void *), void *arg)
204 fn(arg);
205 do_exit(-1);
208 int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
210 struct pt_regs regs;
212 memset(&regs, 0, sizeof(regs));
213 /* store them in non-volatile registers */
214 regs.r5 = (unsigned long)fn;
215 regs.r6 = (unsigned long)arg;
216 local_save_flags(regs.msr);
217 regs.pc = (unsigned long)kernel_thread_helper;
218 regs.pt_mode = 1;
220 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
221 &regs, 0, NULL, NULL);
223 EXPORT_SYMBOL_GPL(kernel_thread);
225 unsigned long get_wchan(struct task_struct *p)
227 /* TBD (used by procfs) */
228 return 0;
231 /* Set up a thread for executing a new program */
232 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
234 set_fs(USER_DS);
235 regs->pc = pc;
236 regs->r1 = usp;
237 regs->pt_mode = 0;
240 #ifdef CONFIG_MMU
241 #include <linux/elfcore.h>
243 * Set up a thread for executing a new program
245 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
247 return 0; /* MicroBlaze has no separate FPU registers */
249 #endif /* CONFIG_MMU */