1#ifndef _ALPHA_SPINLOCK_H
2#define _ALPHA_SPINLOCK_H
3
4#include <linux/config.h>
5#include <asm/system.h>
6#include <linux/kernel.h>
7#include <asm/current.h>
8
9
10/*
11 * Simple spin lock operations.  There are two variants, one clears IRQ's
12 * on the local processor, one does not.
13 *
14 * We make no fairness assumptions. They have a cost.
15 */
16
17typedef struct {
18	volatile unsigned int lock /*__attribute__((aligned(32))) */;
19#if CONFIG_DEBUG_SPINLOCK
20	int on_cpu;
21	int line_no;
22	void *previous;
23	struct task_struct * task;
24	const char *base_file;
25#endif
26} spinlock_t;
27
28#if CONFIG_DEBUG_SPINLOCK
29#define SPIN_LOCK_UNLOCKED (spinlock_t) {0, -1, 0, 0, 0, 0}
30#define spin_lock_init(x)						\
31	((x)->lock = 0, (x)->on_cpu = -1, (x)->previous = 0, (x)->task = 0)
32#else
33#define SPIN_LOCK_UNLOCKED	(spinlock_t) { 0 }
34#define spin_lock_init(x)	((x)->lock = 0)
35#endif
36
37#define spin_is_locked(x)	((x)->lock != 0)
38#define spin_unlock_wait(x)	({ do { barrier(); } while ((x)->lock); })
39
40#if CONFIG_DEBUG_SPINLOCK
41extern void spin_unlock(spinlock_t * lock);
42extern void debug_spin_lock(spinlock_t * lock, const char *, int);
43extern int debug_spin_trylock(spinlock_t * lock, const char *, int);
44
45#define spin_lock(LOCK) debug_spin_lock(LOCK, __BASE_FILE__, __LINE__)
46#define spin_trylock(LOCK) debug_spin_trylock(LOCK, __BASE_FILE__, __LINE__)
47
48#define spin_lock_own(LOCK, LOCATION)					\
49do {									\
50	if (!((LOCK)->lock && (LOCK)->on_cpu == smp_processor_id()))	\
51		printk("%s: called on %d from %p but lock %s on %d\n",	\
52		       LOCATION, smp_processor_id(),			\
53		       __builtin_return_address(0),			\
54		       (LOCK)->lock ? "taken" : "freed", (LOCK)->on_cpu); \
55} while (0)
56#else
57static inline void spin_unlock(spinlock_t * lock)
58{
59	mb();
60	lock->lock = 0;
61}
62
63static inline void spin_lock(spinlock_t * lock)
64{
65	long tmp;
66
67	/* Use sub-sections to put the actual loop at the end
68	   of this object file's text section so as to perfect
69	   branch prediction.  */
70	__asm__ __volatile__(
71	"1:	ldl_l	%0,%1\n"
72	"	blbs	%0,2f\n"
73	"	or	%0,1,%0\n"
74	"	stl_c	%0,%1\n"
75	"	beq	%0,2f\n"
76	"	mb\n"
77	".subsection 2\n"
78	"2:	ldl	%0,%1\n"
79	"	blbs	%0,2b\n"
80	"	br	1b\n"
81	".previous"
82	: "=&r" (tmp), "=m" (lock->lock)
83	: "m"(lock->lock) : "memory");
84}
85
86#define spin_trylock(lock) (!test_and_set_bit(0,(lock)))
87#define spin_lock_own(LOCK, LOCATION)	((void)0)
88#endif /* CONFIG_DEBUG_SPINLOCK */
89
90/***********************************************************/
91
92typedef struct {
93	volatile int write_lock:1, read_counter:31;
94} /*__attribute__((aligned(32)))*/ rwlock_t;
95
96#define RW_LOCK_UNLOCKED (rwlock_t) { 0, 0 }
97
98#define rwlock_init(x)	do { *(x) = RW_LOCK_UNLOCKED; } while(0)
99
100#if CONFIG_DEBUG_RWLOCK
101extern void write_lock(rwlock_t * lock);
102extern void read_lock(rwlock_t * lock);
103#else
104static inline void write_lock(rwlock_t * lock)
105{
106	long regx;
107
108	__asm__ __volatile__(
109	"1:	ldl_l	%1,%0\n"
110	"	bne	%1,6f\n"
111	"	or	$31,1,%1\n"
112	"	stl_c	%1,%0\n"
113	"	beq	%1,6f\n"
114	"	mb\n"
115	".subsection 2\n"
116	"6:	ldl	%1,%0\n"
117	"	bne	%1,6b\n"
118	"	br	1b\n"
119	".previous"
120	: "=m" (*(volatile int *)lock), "=&r" (regx)
121	: "0" (*(volatile int *)lock) : "memory");
122}
123
124static inline void read_lock(rwlock_t * lock)
125{
126	long regx;
127
128	__asm__ __volatile__(
129	"1:	ldl_l	%1,%0\n"
130	"	blbs	%1,6f\n"
131	"	subl	%1,2,%1\n"
132	"	stl_c	%1,%0\n"
133	"	beq	%1,6f\n"
134	"4:	mb\n"
135	".subsection 2\n"
136	"6:	ldl	%1,%0\n"
137	"	blbs	%1,6b\n"
138	"	br	1b\n"
139	".previous"
140	: "=m" (*(volatile int *)lock), "=&r" (regx)
141	: "m" (*(volatile int *)lock) : "memory");
142}
143#endif /* CONFIG_DEBUG_RWLOCK */
144
145static inline void write_unlock(rwlock_t * lock)
146{
147	mb();
148	*(volatile int *)lock = 0;
149}
150
151static inline void read_unlock(rwlock_t * lock)
152{
153	long regx;
154	__asm__ __volatile__(
155	"	mb\n"
156	"1:	ldl_l	%1,%0\n"
157	"	addl	%1,2,%1\n"
158	"	stl_c	%1,%0\n"
159	"	beq	%1,6f\n"
160	".subsection 2\n"
161	"6:	br	1b\n"
162	".previous"
163	: "=m" (*(volatile int *)lock), "=&r" (regx)
164	: "m" (*(volatile int *)lock) : "memory");
165}
166
167#endif /* _ALPHA_SPINLOCK_H */
168