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
11 #include <linux/module.h>
12 #include <linux/sched.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>
20 void show_regs(struct pt_regs *regs)
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);
43 void (*pm_idle)(void);
44 void (*pm_power_off)(void) = NULL;
45 EXPORT_SYMBOL(pm_power_off);
47 static int hlt_counter = 1;
49 void disable_hlt(void)
53 EXPORT_SYMBOL(disable_hlt);
59 EXPORT_SYMBOL(enable_hlt);
61 static int __init nohlt_setup(char *__unused)
66 __setup("nohlt", nohlt_setup);
68 static int __init hlt_setup(char *__unused)
73 __setup("hlt", hlt_setup);
75 void default_idle(void)
78 clear_thread_flag(TIF_POLLING_NRFLAG);
79 smp_mb__after_clear_bit();
81 while (!need_resched())
84 set_thread_flag(TIF_POLLING_NRFLAG);
86 while (!need_resched())
92 set_thread_flag(TIF_POLLING_NRFLAG);
94 /* endless idle loop with no priority at all */
96 void (*idle)(void) = pm_idle;
101 tick_nohz_stop_sched_tick(1);
102 while (!need_resched())
104 tick_nohz_restart_sched_tick();
106 preempt_enable_no_resched();
113 void flush_thread(void)
117 int copy_thread(unsigned long clone_flags, unsigned long usp,
118 unsigned long unused,
119 struct task_struct *p, struct pt_regs *regs)
121 struct pt_regs *childregs = task_pt_regs(p);
122 struct thread_info *ti = task_thread_info(p);
128 childregs->r1 = ((unsigned long) ti) + THREAD_SIZE;
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;
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 */
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 */
152 ti->cpu_context = *(struct cpu_context *)regs;
153 childregs->msr |= MSR_UMS;
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*/
175 ti->cpu_context.msr = (childregs->msr|MSR_VM);
176 ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
178 ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;
180 if (clone_flags & CLONE_SETTLS)
188 * Return saved PC of a blocked thread.
190 unsigned long thread_saved_pc(struct task_struct *tsk)
192 struct cpu_context *ctx =
193 &(((struct thread_info *)(tsk->stack))->cpu_context);
195 /* Check whether the thread is blocked in resume() */
196 if (in_sched_functions(ctx->r15))
197 return (unsigned long)ctx->r15;
203 static void kernel_thread_helper(int (*fn)(void *), void *arg)
209 int kernel_thread(int (*fn)(void *), void *arg, unsigned long flags)
213 memset(®s, 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;
221 return do_fork(flags | CLONE_VM | CLONE_UNTRACED, 0,
222 ®s, 0, NULL, NULL);
224 EXPORT_SYMBOL_GPL(kernel_thread);
226 unsigned long get_wchan(struct task_struct *p)
228 /* TBD (used by procfs) */
232 /* Set up a thread for executing a new program */
233 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
240 regs->msr |= MSR_UMS;
245 #include <linux/elfcore.h>
247 * Set up a thread for executing a new program
249 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
251 return 0; /* MicroBlaze has no separate FPU registers */
253 #endif /* CONFIG_MMU */