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/cpu.h>
12#include <linux/export.h>
13#include <linux/sched.h>
14#include <linux/pm.h>
15#include <linux/tick.h>
16#include <linux/bitops.h>
17#include <linux/ptrace.h>
18#include <asm/pgalloc.h>
19#include <linux/uaccess.h> /* for USER_DS macros */
20#include <asm/cacheflush.h>
21
22void show_regs(struct pt_regs *regs)
23{
24	show_regs_print_info(KERN_INFO);
25
26	pr_info(" Registers dump: mode=%X\r\n", regs->pt_mode);
27	pr_info(" r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n",
28				regs->r1, regs->r2, regs->r3, regs->r4);
29	pr_info(" r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n",
30				regs->r5, regs->r6, regs->r7, regs->r8);
31	pr_info(" r9=%08lX, r10=%08lX, r11=%08lX, r12=%08lX\n",
32				regs->r9, regs->r10, regs->r11, regs->r12);
33	pr_info(" r13=%08lX, r14=%08lX, r15=%08lX, r16=%08lX\n",
34				regs->r13, regs->r14, regs->r15, regs->r16);
35	pr_info(" r17=%08lX, r18=%08lX, r19=%08lX, r20=%08lX\n",
36				regs->r17, regs->r18, regs->r19, regs->r20);
37	pr_info(" r21=%08lX, r22=%08lX, r23=%08lX, r24=%08lX\n",
38				regs->r21, regs->r22, regs->r23, regs->r24);
39	pr_info(" r25=%08lX, r26=%08lX, r27=%08lX, r28=%08lX\n",
40				regs->r25, regs->r26, regs->r27, regs->r28);
41	pr_info(" r29=%08lX, r30=%08lX, r31=%08lX, rPC=%08lX\n",
42				regs->r29, regs->r30, regs->r31, regs->pc);
43	pr_info(" msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n",
44				regs->msr, regs->ear, regs->esr, regs->fsr);
45}
46
47void (*pm_power_off)(void) = NULL;
48EXPORT_SYMBOL(pm_power_off);
49
50void flush_thread(void)
51{
52}
53
54int copy_thread(unsigned long clone_flags, unsigned long usp,
55		unsigned long arg, struct task_struct *p)
56{
57	struct pt_regs *childregs = task_pt_regs(p);
58	struct thread_info *ti = task_thread_info(p);
59
60	if (unlikely(p->flags & PF_KTHREAD)) {
61		/* if we're creating a new kernel thread then just zeroing all
62		 * the registers. That's OK for a brand new thread.*/
63		memset(childregs, 0, sizeof(struct pt_regs));
64		memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
65		ti->cpu_context.r1  = (unsigned long)childregs;
66		ti->cpu_context.r20 = (unsigned long)usp; /* fn */
67		ti->cpu_context.r19 = (unsigned long)arg;
68		childregs->pt_mode = 1;
69		local_save_flags(childregs->msr);
70#ifdef CONFIG_MMU
71		ti->cpu_context.msr = childregs->msr & ~MSR_IE;
72#endif
73		ti->cpu_context.r15 = (unsigned long)ret_from_kernel_thread - 8;
74		return 0;
75	}
76	*childregs = *current_pt_regs();
77	if (usp)
78		childregs->r1 = usp;
79
80	memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
81	ti->cpu_context.r1 = (unsigned long)childregs;
82#ifndef CONFIG_MMU
83	ti->cpu_context.msr = (unsigned long)childregs->msr;
84#else
85	childregs->msr |= MSR_UMS;
86
87	/* we should consider the fact that childregs is a copy of the parent
88	 * regs which were saved immediately after entering the kernel state
89	 * before enabling VM. This MSR will be restored in switch_to and
90	 * RETURN() and we want to have the right machine state there
91	 * specifically this state must have INTs disabled before and enabled
92	 * after performing rtbd
93	 * compose the right MSR for RETURN(). It will work for switch_to also
94	 * excepting for VM and UMS
95	 * don't touch UMS , CARRY and cache bits
96	 * right now MSR is a copy of parent one */
97	childregs->msr &= ~MSR_EIP;
98	childregs->msr |= MSR_IE;
99	childregs->msr &= ~MSR_VM;
100	childregs->msr |= MSR_VMS;
101	childregs->msr |= MSR_EE; /* exceptions will be enabled*/
102
103	ti->cpu_context.msr = (childregs->msr|MSR_VM);
104	ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
105	ti->cpu_context.msr &= ~MSR_IE;
106#endif
107	ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;
108
109	/*
110	 *  r21 is the thread reg, r10 is 6th arg to clone
111	 *  which contains TLS area
112	 */
113	if (clone_flags & CLONE_SETTLS)
114		childregs->r21 = childregs->r10;
115
116	return 0;
117}
118
119#ifndef CONFIG_MMU
120/*
121 * Return saved PC of a blocked thread.
122 */
123unsigned long thread_saved_pc(struct task_struct *tsk)
124{
125	struct cpu_context *ctx =
126		&(((struct thread_info *)(tsk->stack))->cpu_context);
127
128	/* Check whether the thread is blocked in resume() */
129	if (in_sched_functions(ctx->r15))
130		return (unsigned long)ctx->r15;
131	else
132		return ctx->r14;
133}
134#endif
135
136unsigned long get_wchan(struct task_struct *p)
137{
138/* TBD (used by procfs) */
139	return 0;
140}
141
142/* Set up a thread for executing a new program */
143void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
144{
145	regs->pc = pc;
146	regs->r1 = usp;
147	regs->pt_mode = 0;
148#ifdef CONFIG_MMU
149	regs->msr |= MSR_UMS;
150	regs->msr &= ~MSR_VM;
151#endif
152}
153
154#ifdef CONFIG_MMU
155#include <linux/elfcore.h>
156/*
157 * Set up a thread for executing a new program
158 */
159int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
160{
161	return 0; /* MicroBlaze has no separate FPU registers */
162}
163#endif /* CONFIG_MMU */
164
165void arch_cpu_idle(void)
166{
167       local_irq_enable();
168}
169