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

source code of linux/arch/microblaze/kernel/process.c