summaryrefslogtreecommitdiff
path: root/arch/hexagon/include/asm/processor.h
blob: 45a825402f634ee4b650a08a60efc5c60d50e261 (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
/*
 * Process/processor support for the Hexagon architecture
 *
 * Copyright (c) 2010-2012, The Linux Foundation. All rights reserved.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License version 2 and
 * only version 2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
 * 02110-1301, USA.
 */

#ifndef _ASM_PROCESSOR_H
#define _ASM_PROCESSOR_H

#ifndef __ASSEMBLY__

#include <asm/mem-layout.h>
#include <asm/registers.h>
#include <asm/hexagon_vm.h>

/*  must be a macro  */
#define current_text_addr() ({ __label__ _l; _l: &&_l; })

/*  task_struct, defined elsewhere, is the "process descriptor" */
struct task_struct;

/*  this is defined in arch/process.c  */
extern unsigned long thread_saved_pc(struct task_struct *tsk);

extern void start_thread(struct pt_regs *, unsigned long, unsigned long);

/*
 * thread_struct is supposed to be for context switch data.
 * Specifically, to hold the state necessary to perform switch_to...
 */
struct thread_struct {
	void *switch_sp;
};

/*
 * initializes thread_struct
 * The only thing we have in there is switch_sp
 * which doesn't really need to be initialized.
 */

#define INIT_THREAD { \
}

#define cpu_relax() __vmyield()

/*
 * Decides where the kernel will search for a free chunk of vm space during
 * mmaps.
 * See also arch_get_unmapped_area.
 * Doesn't affect if you have MAX_FIXED in the page flags set though...
 *
 * Apparently the convention is that ld.so will ask for "unmapped" private
 * memory to be allocated SOMEWHERE, but it also asks for memory explicitly
 * via MAP_FIXED at the lower * addresses starting at VA=0x0.
 *
 * If the two requests collide, you get authentic segfaulting action, so
 * you have to kick the "unmapped" base requests higher up.
 */
#define TASK_UNMAPPED_BASE	(PAGE_ALIGN(TASK_SIZE/3))


#define task_pt_regs(task) \
	((struct pt_regs *)(task_stack_page(task) + THREAD_SIZE) - 1)

#define KSTK_EIP(tsk) (pt_elr(task_pt_regs(tsk)))
#define KSTK_ESP(tsk) (pt_psp(task_pt_regs(tsk)))

/*  Free all resources held by a thread; defined in process.c  */
extern void release_thread(struct task_struct *dead_task);

/* Get wait channel for task P.  */
extern unsigned long get_wchan(struct task_struct *p);

/*  The following stuff is pretty HEXAGON specific.  */

/*  This is really just here for __switch_to.
    Offsets are pulled via asm-offsets.c  */

/*
 * No real reason why VM and native switch stacks should be different.
 * Ultimately this should merge.  Note that Rev C. ABI called out only
 * R24-27 as callee saved GPRs needing explicit attention (R29-31 being
 * dealt with automagically by allocframe), but the current ABI has
 * more, R16-R27.  By saving more, the worst case is that we waste some
 * cycles if building with the old compilers.
 */

struct hexagon_switch_stack {
	union {
		struct {
			unsigned long r16;
			unsigned long r17;
		};
		unsigned long long	r1716;
	};
	union {
		struct {
			unsigned long r18;
			unsigned long r19;
		};
		unsigned long long	r1918;
	};
	union {
		struct {
			unsigned long r20;
			unsigned long r21;
		};
		unsigned long long	r2120;
	};
	union {
		struct {
			unsigned long r22;
			unsigned long r23;
		};
		unsigned long long	r2322;
	};
	union {
		struct {
			unsigned long r24;
			unsigned long r25;
		};
		unsigned long long	r2524;
	};
	union {
		struct {
			unsigned long r26;
			unsigned long r27;
		};
		unsigned long long	r2726;
	};

	unsigned long		fp;
	unsigned long		lr;
};

#endif /* !__ASSEMBLY__ */

#endif