summaryrefslogtreecommitdiff
path: root/arch/sh/kernel/process_32.c
blob: ee12e94518740829165d7fbcb597fbad90664c5f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
/*
 * arch/sh/kernel/process.c
 *
 * This file handles the architecture-dependent parts of process handling..
 *
 *  Copyright (C) 1995  Linus Torvalds
 *
 *  SuperH version:  Copyright (C) 1999, 2000  Niibe Yutaka & Kaz Kojima
 *		     Copyright (C) 2006 Lineo Solutions Inc. support SH4A UBC
 *		     Copyright (C) 2002 - 2008  Paul Mundt
 *
 * This file is subject to the terms and conditions of the GNU General Public
 * License.  See the file "COPYING" in the main directory of this archive
 * for more details.
 */
#include <linux/module.h>
#include <linux/mm.h>
#include <linux/slab.h>
#include <linux/elfcore.h>
#include <linux/kallsyms.h>
#include <linux/fs.h>
#include <linux/ftrace.h>
#include <linux/hw_breakpoint.h>
#include <linux/prefetch.h>
#include <linux/stackprotector.h>
#include <asm/uaccess.h>
#include <asm/mmu_context.h>
#include <asm/fpu.h>
#include <asm/syscalls.h>
#include <asm/switch_to.h>

void show_regs(struct pt_regs * regs)
{
	printk("\n");
	show_regs_print_info(KERN_DEFAULT);

	print_symbol("PC is at %s\n", instruction_pointer(regs));
	print_symbol("PR is at %s\n", regs->pr);

	printk("PC  : %08lx SP  : %08lx SR  : %08lx ",
	       regs->pc, regs->regs[15], regs->sr);
#ifdef CONFIG_MMU
	printk("TEA : %08x\n", __raw_readl(MMU_TEA));
#else
	printk("\n");
#endif

	printk("R0  : %08lx R1  : %08lx R2  : %08lx R3  : %08lx\n",
	       regs->regs[0],regs->regs[1],
	       regs->regs[2],regs->regs[3]);
	printk("R4  : %08lx R5  : %08lx R6  : %08lx R7  : %08lx\n",
	       regs->regs[4],regs->regs[5],
	       regs->regs[6],regs->regs[7]);
	printk("R8  : %08lx R9  : %08lx R10 : %08lx R11 : %08lx\n",
	       regs->regs[8],regs->regs[9],
	       regs->regs[10],regs->regs[11]);
	printk("R12 : %08lx R13 : %08lx R14 : %08lx\n",
	       regs->regs[12],regs->regs[13],
	       regs->regs[14]);
	printk("MACH: %08lx MACL: %08lx GBR : %08lx PR  : %08lx\n",
	       regs->mach, regs->macl, regs->gbr, regs->pr);

	show_trace(NULL, (unsigned long *)regs->regs[15], regs);
	show_code(regs);
}

void start_thread(struct pt_regs *regs, unsigned long new_pc,
		  unsigned long new_sp)
{
	regs->pr = 0;
	regs->sr = SR_FD;
	regs->pc = new_pc;
	regs->regs[15] = new_sp;

	free_thread_xstate(current);
}
EXPORT_SYMBOL(start_thread);

void flush_thread(void)
{
	struct task_struct *tsk = current;

	flush_ptrace_hw_breakpoint(tsk);

#if defined(CONFIG_SH_FPU)
	/* Forget lazy FPU state */
	clear_fpu(tsk, task_pt_regs(tsk));
	clear_used_math();
#endif
}

void release_thread(struct task_struct *dead_task)
{
	/* do nothing */
}

/* Fill in the fpu structure for a core dump.. */
int dump_fpu(struct pt_regs *regs, elf_fpregset_t *fpu)
{
	int fpvalid = 0;

#if defined(CONFIG_SH_FPU)
	struct task_struct *tsk = current;

	fpvalid = !!tsk_used_math(tsk);
	if (fpvalid)
		fpvalid = !fpregs_get(tsk, NULL, 0,
				      sizeof(struct user_fpu_struct),
				      fpu, NULL);
#endif

	return fpvalid;
}
EXPORT_SYMBOL(dump_fpu);

asmlinkage void ret_from_fork(void);
asmlinkage void ret_from_kernel_thread(void);

int copy_thread(unsigned long clone_flags, unsigned long usp,
		unsigned long arg, struct task_struct *p)
{
	struct thread_info *ti = task_thread_info(p);
	struct pt_regs *childregs;

#if defined(CONFIG_SH_DSP)
	struct task_struct *tsk = current;

	if (is_dsp_enabled(tsk)) {
		/* We can use the __save_dsp or just copy the struct:
		 * __save_dsp(p);
		 * p->thread.dsp_status.status |= SR_DSP
		 */
		p->thread.dsp_status = tsk->thread.dsp_status;
	}
#endif

	memset(p->thread.ptrace_bps, 0, sizeof(p->thread.ptrace_bps));

	childregs = task_pt_regs(p);
	p->thread.sp = (unsigned long) childregs;
	if (unlikely(p->flags & PF_KTHREAD)) {
		memset(childregs, 0, sizeof(struct pt_regs));
		p->thread.pc = (unsigned long) ret_from_kernel_thread;
		childregs->regs[4] = arg;
		childregs->regs[5] = usp;
		childregs->sr = SR_MD;
#if defined(CONFIG_SH_FPU)
		childregs->sr |= SR_FD;
#endif
		ti->addr_limit = KERNEL_DS;
		ti->status &= ~TS_USEDFPU;
		p->thread.fpu_counter = 0;
		return 0;
	}
	*childregs = *current_pt_regs();

	if (usp)
		childregs->regs[15] = usp;
	ti->addr_limit = USER_DS;

	if (clone_flags & CLONE_SETTLS)
		childregs->gbr = childregs->regs[0];

	childregs->regs[0] = 0; /* Set return value for child */
	p->thread.pc = (unsigned long) ret_from_fork;
	return 0;
}

/*
 *	switch_to(x,y) should switch tasks from x to y.
 *
 */
__notrace_funcgraph struct task_struct *
__switch_to(struct task_struct *prev, struct task_struct *next)
{
	struct thread_struct *next_t = &next->thread;

#if defined(CONFIG_CC_STACKPROTECTOR) && !defined(CONFIG_SMP)
	__stack_chk_guard = next->stack_canary;
#endif

	unlazy_fpu(prev, task_pt_regs(prev));

	/* we're going to use this soon, after a few expensive things */
	if (next->thread.fpu_counter > 5)
		prefetch(next_t->xstate);

#ifdef CONFIG_MMU
	/*
	 * Restore the kernel mode register
	 *	k7 (r7_bank1)
	 */
	asm volatile("ldc	%0, r7_bank"
		     : /* no output */
		     : "r" (task_thread_info(next)));
#endif

	/*
	 * If the task has used fpu the last 5 timeslices, just do a full
	 * restore of the math state immediately to avoid the trap; the
	 * chances of needing FPU soon are obviously high now
	 */
	if (next->thread.fpu_counter > 5)
		__fpu_state_restore();

	return prev;
}

unsigned long get_wchan(struct task_struct *p)
{
	unsigned long pc;

	if (!p || p == current || p->state == TASK_RUNNING)
		return 0;

	/*
	 * The same comment as on the Alpha applies here, too ...
	 */
	pc = thread_saved_pc(p);

#ifdef CONFIG_FRAME_POINTER
	if (in_sched_functions(pc)) {
		unsigned long schedule_frame = (unsigned long)p->thread.sp;
		return ((unsigned long *)schedule_frame)[21];
	}
#endif

	return pc;
}