7cce2e9c171992e52656717c6b5908464c90608d
[linux-3.10.git] / arch / microblaze / kernel / process.c
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/export.h>
12 #include <linux/sched.h>
13 #include <linux/pm.h>
14 #include <linux/tick.h>
15 #include <linux/bitops.h>
16 #include <linux/ptrace.h>
17 #include <asm/pgalloc.h>
18 #include <linux/uaccess.h> /* for USER_DS macros */
19 #include <asm/cacheflush.h>
20
21 void show_regs(struct pt_regs *regs)
22 {
23         pr_info(" Registers dump: mode=%X\r\n", regs->pt_mode);
24         pr_info(" r1=%08lX, r2=%08lX, r3=%08lX, r4=%08lX\n",
25                                 regs->r1, regs->r2, regs->r3, regs->r4);
26         pr_info(" r5=%08lX, r6=%08lX, r7=%08lX, r8=%08lX\n",
27                                 regs->r5, regs->r6, regs->r7, regs->r8);
28         pr_info(" r9=%08lX, r10=%08lX, r11=%08lX, r12=%08lX\n",
29                                 regs->r9, regs->r10, regs->r11, regs->r12);
30         pr_info(" r13=%08lX, r14=%08lX, r15=%08lX, r16=%08lX\n",
31                                 regs->r13, regs->r14, regs->r15, regs->r16);
32         pr_info(" r17=%08lX, r18=%08lX, r19=%08lX, r20=%08lX\n",
33                                 regs->r17, regs->r18, regs->r19, regs->r20);
34         pr_info(" r21=%08lX, r22=%08lX, r23=%08lX, r24=%08lX\n",
35                                 regs->r21, regs->r22, regs->r23, regs->r24);
36         pr_info(" r25=%08lX, r26=%08lX, r27=%08lX, r28=%08lX\n",
37                                 regs->r25, regs->r26, regs->r27, regs->r28);
38         pr_info(" r29=%08lX, r30=%08lX, r31=%08lX, rPC=%08lX\n",
39                                 regs->r29, regs->r30, regs->r31, regs->pc);
40         pr_info(" msr=%08lX, ear=%08lX, esr=%08lX, fsr=%08lX\n",
41                                 regs->msr, regs->ear, regs->esr, regs->fsr);
42 }
43
44 void (*pm_power_off)(void) = NULL;
45 EXPORT_SYMBOL(pm_power_off);
46
47 void flush_thread(void)
48 {
49 }
50
51 int copy_thread(unsigned long clone_flags, unsigned long usp,
52                 unsigned long arg, struct task_struct *p)
53 {
54         struct pt_regs *childregs = task_pt_regs(p);
55         struct thread_info *ti = task_thread_info(p);
56
57         if (unlikely(p->flags & PF_KTHREAD)) {
58                 /* if we're creating a new kernel thread then just zeroing all
59                  * the registers. That's OK for a brand new thread.*/
60                 memset(childregs, 0, sizeof(struct pt_regs));
61                 memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
62                 ti->cpu_context.r1  = (unsigned long)childregs;
63                 ti->cpu_context.r20 = (unsigned long)usp; /* fn */
64                 ti->cpu_context.r19 = (unsigned long)arg;
65                 childregs->pt_mode = 1;
66                 local_save_flags(childregs->msr);
67 #ifdef CONFIG_MMU
68                 ti->cpu_context.msr = childregs->msr & ~MSR_IE;
69 #endif
70                 ti->cpu_context.r15 = (unsigned long)ret_from_kernel_thread - 8;
71                 return 0;
72         }
73         *childregs = *current_pt_regs();
74         if (usp)
75                 childregs->r1 = usp;
76
77         memset(&ti->cpu_context, 0, sizeof(struct cpu_context));
78         ti->cpu_context.r1 = (unsigned long)childregs;
79 #ifndef CONFIG_MMU
80         ti->cpu_context.msr = (unsigned long)childregs->msr;
81 #else
82         childregs->msr |= MSR_UMS;
83
84         /* we should consider the fact that childregs is a copy of the parent
85          * regs which were saved immediately after entering the kernel state
86          * before enabling VM. This MSR will be restored in switch_to and
87          * RETURN() and we want to have the right machine state there
88          * specifically this state must have INTs disabled before and enabled
89          * after performing rtbd
90          * compose the right MSR for RETURN(). It will work for switch_to also
91          * excepting for VM and UMS
92          * don't touch UMS , CARRY and cache bits
93          * right now MSR is a copy of parent one */
94         childregs->msr &= ~MSR_EIP;
95         childregs->msr |= MSR_IE;
96         childregs->msr &= ~MSR_VM;
97         childregs->msr |= MSR_VMS;
98         childregs->msr |= MSR_EE; /* exceptions will be enabled*/
99
100         ti->cpu_context.msr = (childregs->msr|MSR_VM);
101         ti->cpu_context.msr &= ~MSR_UMS; /* switch_to to kernel mode */
102         ti->cpu_context.msr &= ~MSR_IE;
103 #endif
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 = childregs->r10;
112
113         return 0;
114 }
115
116 #ifndef CONFIG_MMU
117 /*
118  * Return saved PC of a blocked thread.
119  */
120 unsigned long thread_saved_pc(struct task_struct *tsk)
121 {
122         struct cpu_context *ctx =
123                 &(((struct thread_info *)(tsk->stack))->cpu_context);
124
125         /* Check whether the thread is blocked in resume() */
126         if (in_sched_functions(ctx->r15))
127                 return (unsigned long)ctx->r15;
128         else
129                 return ctx->r14;
130 }
131 #endif
132
133 unsigned long get_wchan(struct task_struct *p)
134 {
135 /* TBD (used by procfs) */
136         return 0;
137 }
138
139 /* Set up a thread for executing a new program */
140 void start_thread(struct pt_regs *regs, unsigned long pc, unsigned long usp)
141 {
142         regs->pc = pc;
143         regs->r1 = usp;
144         regs->pt_mode = 0;
145 #ifdef CONFIG_MMU
146         regs->msr |= MSR_UMS;
147         regs->msr &= ~MSR_VM;
148 #endif
149 }
150
151 #ifdef CONFIG_MMU
152 #include <linux/elfcore.h>
153 /*
154  * Set up a thread for executing a new program
155  */
156 int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpregs)
157 {
158         return 0; /* MicroBlaze has no separate FPU registers */
159 }
160 #endif /* CONFIG_MMU */