summaryrefslogtreecommitdiffstats
path: root/include/asm-ia64/spinlock.h
blob: 0c91a76c5ea3cff8decee9debe0cf45d696a83c7 (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
#ifndef _ASM_IA64_SPINLOCK_H
#define _ASM_IA64_SPINLOCK_H

/*
 * Copyright (C) 1998-2003 Hewlett-Packard Co
 *	David Mosberger-Tang <davidm@hpl.hp.com>
 * Copyright (C) 1999 Walt Drummond <drummond@valinux.com>
 *
 * This file is used for SMP configurations only.
 */

#include <linux/compiler.h>
#include <linux/kernel.h>

#include <asm/atomic.h>
#include <asm/bitops.h>
#include <asm/intrinsics.h>
#include <asm/system.h>

#define __raw_spin_lock_init(x)			((x)->lock = 0)

#ifdef ASM_SUPPORTED
/*
 * Try to get the lock.  If we fail to get the lock, make a non-standard call to
 * ia64_spinlock_contention().  We do not use a normal call because that would force all
 * callers of __raw_spin_lock() to be non-leaf routines.  Instead, ia64_spinlock_contention() is
 * carefully coded to touch only those registers that __raw_spin_lock() marks "clobbered".
 */

#define IA64_SPINLOCK_CLOBBERS "ar.ccv", "ar.pfs", "p14", "p15", "r27", "r28", "r29", "r30", "b6", "memory"

static inline void
__raw_spin_lock_flags (raw_spinlock_t *lock, unsigned long flags)
{
	register volatile unsigned int *ptr asm ("r31") = &lock->lock;

#if __GNUC__ < 3 || (__GNUC__ == 3 && __GNUC_MINOR__ < 3)
# ifdef CONFIG_ITANIUM
	/* don't use brl on Itanium... */
	asm volatile ("{\n\t"
		      "  mov ar.ccv = r0\n\t"
		      "  mov r28 = ip\n\t"
		      "  mov r30 = 1;;\n\t"
		      "}\n\t"
		      "cmpxchg4.acq r30 = [%1], r30, ar.ccv\n\t"
		      "movl r29 = ia64_spinlock_contention_pre3_4;;\n\t"
		      "cmp4.ne p14, p0 = r30, r0\n\t"
		      "mov b6 = r29;;\n\t"
		      "mov r27=%2\n\t"
		      "(p14) br.cond.spnt.many b6"
		      : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS);
# else
	asm volatile ("{\n\t"
		      "  mov ar.ccv = r0\n\t"
		      "  mov r28 = ip\n\t"
		      "  mov r30 = 1;;\n\t"
		      "}\n\t"
		      "cmpxchg4.acq r30 = [%1], r30, ar.ccv;;\n\t"
		      "cmp4.ne p14, p0 = r30, r0\n\t"
		      "mov r27=%2\n\t"
		      "(p14) brl.cond.spnt.many ia64_spinlock_contention_pre3_4;;"
		      : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS);
# endif /* CONFIG_MCKINLEY */
#else
# ifdef CONFIG_ITANIUM
	/* don't use brl on Itanium... */
	/* mis-declare, so we get the entry-point, not it's function descriptor: */
	asm volatile ("mov r30 = 1\n\t"
		      "mov r27=%2\n\t"
		      "mov ar.ccv = r0;;\n\t"
		      "cmpxchg4.acq r30 = [%0], r30, ar.ccv\n\t"
		      "movl r29 = ia64_spinlock_contention;;\n\t"
		      "cmp4.ne p14, p0 = r30, r0\n\t"
		      "mov b6 = r29;;\n\t"
		      "(p14) br.call.spnt.many b6 = b6"
		      : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS);
# else
	asm volatile ("mov r30 = 1\n\t"
		      "mov r27=%2\n\t"
		      "mov ar.ccv = r0;;\n\t"
		      "cmpxchg4.acq r30 = [%0], r30, ar.ccv;;\n\t"
		      "cmp4.ne p14, p0 = r30, r0\n\t"
		      "(p14) brl.call.spnt.many b6=ia64_spinlock_contention;;"
		      : "=r"(ptr) : "r"(ptr), "r" (flags) : IA64_SPINLOCK_CLOBBERS);
# endif /* CONFIG_MCKINLEY */
#endif
}

#define __raw_spin_lock(lock) __raw_spin_lock_flags(lock, 0)

/* Unlock by doing an ordered store and releasing the cacheline with nta */
static inline void __raw_spin_unlock(raw_spinlock_t *x) {
	barrier();
	asm volatile ("st4.rel.nta [%0] = r0\n\t" :: "r"(x));
}

#else /* !ASM_SUPPORTED */
#define __raw_spin_lock_flags(lock, flags) __raw_spin_lock(lock)
# define __raw_spin_lock(x)								\
do {											\
	__u32 *ia64_spinlock_ptr = (__u32 *) (x);					\
	__u64 ia64_spinlock_val;							\
	ia64_spinlock_val = ia64_cmpxchg4_acq(ia64_spinlock_ptr, 1, 0);			\
	if (unlikely(ia64_spinlock_val)) {						\
		do {									\
			while (*ia64_spinlock_ptr)					\
				ia64_barrier();						\
			ia64_spinlock_val = ia64_cmpxchg4_acq(ia64_spinlock_ptr, 1, 0);	\
		} while (ia64_spinlock_val);						\
	}										\
} while (0)
#define __raw_spin_unlock(x)	do { barrier(); ((raw_spinlock_t *) x)->lock = 0; } while (0)
#endif /* !ASM_SUPPORTED */

#define __raw_spin_is_locked(x)		((x)->lock != 0)
#define __raw_spin_trylock(x)		(cmpxchg_acq(&(x)->lock, 0, 1) == 0)
#define __raw_spin_unlock_wait(lock) \
	do { while (__raw_spin_is_locked(lock)) cpu_relax(); } while (0)

#define __raw_read_can_lock(rw)		(*(volatile int *)(rw) >= 0)
#define __raw_write_can_lock(rw)	(*(volatile int *)(rw) == 0)

#define __raw_read_lock(rw)								\
do {											\
	raw_rwlock_t *__read_lock_ptr = (rw);						\
											\
	while (unlikely(ia64_fetchadd(1, (int *) __read_lock_ptr, acq) < 0)) {		\
		ia64_fetchadd(-1, (int *) __read_lock_ptr, rel);			\
		while (*(volatile int *)__read_lock_ptr < 0)				\
			cpu_relax();							\
	}										\
} while (0)

#define __raw_read_unlock(rw)					\
do {								\
	raw_rwlock_t *__read_lock_ptr = (rw);			\
	ia64_fetchadd(-1, (int *) __read_lock_ptr, rel);	\
} while (0)

#ifdef ASM_SUPPORTED
#define __raw_write_lock(rw)							\
do {										\
 	__asm__ __volatile__ (							\
		"mov ar.ccv = r0\n"						\
		"dep r29 = -1, r0, 31, 1;;\n"					\
		"1:\n"								\
		"ld4 r2 = [%0];;\n"						\
		"cmp4.eq p0,p7 = r0,r2\n"					\
		"(p7) br.cond.spnt.few 1b \n"					\
		"cmpxchg4.acq r2 = [%0], r29, ar.ccv;;\n"			\
		"cmp4.eq p0,p7 = r0, r2\n"					\
		"(p7) br.cond.spnt.few 1b;;\n"					\
		:: "r"(rw) : "ar.ccv", "p7", "r2", "r29", "memory");		\
} while(0)

#define __raw_write_trylock(rw)							\
({										\
	register long result;							\
										\
	__asm__ __volatile__ (							\
		"mov ar.ccv = r0\n"						\
		"dep r29 = -1, r0, 31, 1;;\n"					\
		"cmpxchg4.acq %0 = [%1], r29, ar.ccv\n"				\
		: "=r"(result) : "r"(rw) : "ar.ccv", "r29", "memory");		\
	(result == 0);								\
})

static inline void __raw_write_unlock(raw_rwlock_t *x)
{
	u8 *y = (u8 *)x;
	barrier();
	asm volatile ("st1.rel.nta [%0] = r0\n\t" :: "r"(y+3) : "memory" );
}

#else /* !ASM_SUPPORTED */

#define __raw_write_lock(l)								\
({											\
	__u64 ia64_val, ia64_set_val = ia64_dep_mi(-1, 0, 31, 1);			\
	__u32 *ia64_write_lock_ptr = (__u32 *) (l);					\
	do {										\
		while (*ia64_write_lock_ptr)						\
			ia64_barrier();							\
		ia64_val = ia64_cmpxchg4_acq(ia64_write_lock_ptr, ia64_set_val, 0);	\
	} while (ia64_val);								\
})

#define __raw_write_trylock(rw)						\
({									\
	__u64 ia64_val;							\
	__u64 ia64_set_val = ia64_dep_mi(-1, 0, 31,1);			\
	ia64_val = ia64_cmpxchg4_acq((__u32 *)(rw), ia64_set_val, 0);	\
	(ia64_val == 0);						\
})

static inline void __raw_write_unlock(raw_rwlock_t *x)
{
	barrier();
	x->write_lock = 0;
}

#endif /* !ASM_SUPPORTED */

static inline int __raw_read_trylock(raw_rwlock_t *x)
{
	union {
		raw_rwlock_t lock;
		__u32 word;
	} old, new;
	old.lock = new.lock = *x;
	old.lock.write_lock = new.lock.write_lock = 0;
	++new.lock.read_counter;
	return (u32)ia64_cmpxchg4_acq((__u32 *)(x), new.word, old.word) == old.word;
}

#endif /*  _ASM_IA64_SPINLOCK_H */