xref: /openbmc/linux/arch/microblaze/kernel/process.c (revision fbb6b31a)
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 
23 void 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 
48 void (*pm_power_off)(void) = NULL;
49 EXPORT_SYMBOL(pm_power_off);
50 
51 void flush_thread(void)
52 {
53 }
54 
55 int copy_thread(unsigned long clone_flags, unsigned long usp, unsigned long arg,
56 		struct task_struct *p, unsigned long tls)
57 {
58 	struct pt_regs *childregs = task_pt_regs(p);
59 	struct thread_info *ti = task_thread_info(p);
60 
61 	if (unlikely(p->flags & (PF_KTHREAD | PF_IO_WORKER))) {
62 		/* if we're creating a new kernel thread then just zeroing all
63 		 * the registers. That's OK for a brand new thread.*/
64 		memset(childregs, 0, sizeof(struct pt_regs));
65 		memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
66 		ti->cpu_context.r1  = (unsigned long)childregs;
67 		ti->cpu_context.r20 = (unsigned long)usp; /* fn */
68 		ti->cpu_context.r19 = (unsigned long)arg;
69 		childregs->pt_mode = 1;
70 		local_save_flags(childregs->msr);
71 		ti->cpu_context.msr = childregs->msr & ~MSR_IE;
72 		ti->cpu_context.r15 = (unsigned long)ret_from_kernel_thread - 8;
73 		return 0;
74 	}
75 	*childregs = *current_pt_regs();
76 	if (usp)
77 		childregs->r1 = usp;
78 
79 	memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
80 	ti->cpu_context.r1 = (unsigned long)childregs;
81 	childregs->msr |= MSR_UMS;
82 
83 	/* we should consider the fact that childregs is a copy of the parent
84 	 * regs which were saved immediately after entering the kernel state
85 	 * before enabling VM. This MSR will be restored in switch_to and
86 	 * RETURN() and we want to have the right machine state there
87 	 * specifically this state must have INTs disabled before and enabled
88 	 * after performing rtbd
89 	 * compose the right MSR for RETURN(). It will work for switch_to also
90 	 * excepting for VM and UMS
91 	 * don't touch UMS , CARRY and cache bits
92 	 * right now MSR is a copy of parent one */
93 	childregs->msr &= ~MSR_EIP;
94 	childregs->msr |= MSR_IE;
95 	childregs->msr &= ~MSR_VM;
96 	childregs->msr |= MSR_VMS;
97 	childregs->msr |= MSR_EE; /* exceptions will be enabled*/
98 
99 	ti->cpu_context.msr = (childregs->msr|MSR_VM);
100 	ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
101 	ti->cpu_context.msr &= ~MSR_IE;
102 	ti->cpu_context.r15 = (unsigned long)ret_from_fork - 8;
103 
104 	/*
105 	 *  r21 is the thread reg, r10 is 6th arg to clone
106 	 *  which contains TLS area
107 	 */
108 	if (clone_flags & CLONE_SETTLS)
109 		childregs->r21 = tls;
110 
111 	return 0;
112 }
113 
114 unsigned long __get_wchan(struct task_struct *p)
115 {
116 /* TBD (used by procfs) */
117 	return 0;
118 }
119 
120 /* Set up a thread for executing a new program */
121 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
122 {
123 	regs->pc = pc;
124 	regs->r1 = usp;
125 	regs->pt_mode = 0;
126 	regs->msr |= MSR_UMS;
127 	regs->msr &= ~MSR_VM;
128 }
129 
130 #include <linux/elfcore.h>
131 /*
132  * Set up a thread for executing a new program
133  */
134 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
135 {
136 	return 0; /* MicroBlaze has no separate FPU registers */
137 }
138 
139 void arch_cpu_idle(void)
140 {
141        raw_local_irq_enable();
142 }
143