1/*
  2 * Copyright 2010 Tilera Corporation. All Rights Reserved.
  3 *
  4 *   This program is free software; you can redistribute it and/or
  5 *   modify it under the terms of the GNU General Public License
  6 *   as published by the Free Software Foundation, version 2.
  7 *
  8 *   This program is distributed in the hope that it will be useful, but
  9 *   WITHOUT ANY WARRANTY; without even the implied warranty of
 10 *   MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
 11 *   NON INFRINGEMENT.  See the GNU General Public License for
 12 *   more details.
 13 *
 14 * Do not include directly; use <linux/atomic.h>.
 15 */
 16
 17#ifndef _ASM_TILE_ATOMIC_32_H
 18#define _ASM_TILE_ATOMIC_32_H
 19
 20#include <asm/barrier.h>
 21#include <arch/chip.h>
 22
 23#ifndef __ASSEMBLY__
 24
 25/**
 26 * atomic_add - add integer to atomic variable
 27 * @i: integer value to add
 28 * @v: pointer of type atomic_t
 29 *
 30 * Atomically adds @i to @v.
 31 */
 32static inline void atomic_add(int i, atomic_t *v)
 33{
 34	_atomic_xchg_add(&v->counter, i);
 35}
 36
 37#define ATOMIC_OP(op)							\
 38unsigned long _atomic_##op(volatile unsigned long *p, unsigned long mask); \
 39static inline void atomic_##op(int i, atomic_t *v)			\
 40{									\
 41	_atomic_##op((unsigned long *)&v->counter, i);			\
 42}
 43
 44ATOMIC_OP(and)
 45ATOMIC_OP(or)
 46ATOMIC_OP(xor)
 47
 48#undef ATOMIC_OP
 49
 50/**
 51 * atomic_add_return - add integer and return
 52 * @v: pointer of type atomic_t
 53 * @i: integer value to add
 54 *
 55 * Atomically adds @i to @v and returns @i + @v
 56 */
 57static inline int atomic_add_return(int i, atomic_t *v)
 58{
 59	smp_mb();  /* barrier for proper semantics */
 60	return _atomic_xchg_add(&v->counter, i) + i;
 61}
 62
 63/**
 64 * __atomic_add_unless - add unless the number is already a given value
 65 * @v: pointer of type atomic_t
 66 * @a: the amount to add to v...
 67 * @u: ...unless v is equal to u.
 68 *
 69 * Atomically adds @a to @v, so long as @v was not already @u.
 70 * Returns the old value of @v.
 71 */
 72static inline int __atomic_add_unless(atomic_t *v, int a, int u)
 73{
 74	smp_mb();  /* barrier for proper semantics */
 75	return _atomic_xchg_add_unless(&v->counter, a, u);
 76}
 77
 78/**
 79 * atomic_set - set atomic variable
 80 * @v: pointer of type atomic_t
 81 * @i: required value
 82 *
 83 * Atomically sets the value of @v to @i.
 84 *
 85 * atomic_set() can't be just a raw store, since it would be lost if it
 86 * fell between the load and store of one of the other atomic ops.
 87 */
 88static inline void atomic_set(atomic_t *v, int n)
 89{
 90	_atomic_xchg(&v->counter, n);
 91}
 92
 93/* A 64bit atomic type */
 94
 95typedef struct {
 96	long long counter;
 97} atomic64_t;
 98
 99#define ATOMIC64_INIT(val) { (val) }
100
101/**
102 * atomic64_read - read atomic variable
103 * @v: pointer of type atomic64_t
104 *
105 * Atomically reads the value of @v.
106 */
107static inline long long atomic64_read(const atomic64_t *v)
108{
109	/*
110	 * Requires an atomic op to read both 32-bit parts consistently.
111	 * Casting away const is safe since the atomic support routines
112	 * do not write to memory if the value has not been modified.
113	 */
114	return _atomic64_xchg_add((long long *)&v->counter, 0);
115}
116
117/**
118 * atomic64_add - add integer to atomic variable
119 * @i: integer value to add
120 * @v: pointer of type atomic64_t
121 *
122 * Atomically adds @i to @v.
123 */
124static inline void atomic64_add(long long i, atomic64_t *v)
125{
126	_atomic64_xchg_add(&v->counter, i);
127}
128
129#define ATOMIC64_OP(op)						\
130long long _atomic64_##op(long long *v, long long n);		\
131static inline void atomic64_##op(long long i, atomic64_t *v)	\
132{								\
133	_atomic64_##op(&v->counter, i);				\
134}
135
136ATOMIC64_OP(and)
137ATOMIC64_OP(or)
138ATOMIC64_OP(xor)
139
140/**
141 * atomic64_add_return - add integer and return
142 * @v: pointer of type atomic64_t
143 * @i: integer value to add
144 *
145 * Atomically adds @i to @v and returns @i + @v
146 */
147static inline long long atomic64_add_return(long long i, atomic64_t *v)
148{
149	smp_mb();  /* barrier for proper semantics */
150	return _atomic64_xchg_add(&v->counter, i) + i;
151}
152
153/**
154 * atomic64_add_unless - add unless the number is already a given value
155 * @v: pointer of type atomic64_t
156 * @a: the amount to add to v...
157 * @u: ...unless v is equal to u.
158 *
159 * Atomically adds @a to @v, so long as @v was not already @u.
160 * Returns non-zero if @v was not @u, and zero otherwise.
161 */
162static inline long long atomic64_add_unless(atomic64_t *v, long long a,
163					long long u)
164{
165	smp_mb();  /* barrier for proper semantics */
166	return _atomic64_xchg_add_unless(&v->counter, a, u) != u;
167}
168
169/**
170 * atomic64_set - set atomic variable
171 * @v: pointer of type atomic64_t
172 * @i: required value
173 *
174 * Atomically sets the value of @v to @i.
175 *
176 * atomic64_set() can't be just a raw store, since it would be lost if it
177 * fell between the load and store of one of the other atomic ops.
178 */
179static inline void atomic64_set(atomic64_t *v, long long n)
180{
181	_atomic64_xchg(&v->counter, n);
182}
183
184#define atomic64_add_negative(a, v)	(atomic64_add_return((a), (v)) < 0)
185#define atomic64_inc(v)			atomic64_add(1LL, (v))
186#define atomic64_inc_return(v)		atomic64_add_return(1LL, (v))
187#define atomic64_inc_and_test(v)	(atomic64_inc_return(v) == 0)
188#define atomic64_sub_return(i, v)	atomic64_add_return(-(i), (v))
189#define atomic64_sub_and_test(a, v)	(atomic64_sub_return((a), (v)) == 0)
190#define atomic64_sub(i, v)		atomic64_add(-(i), (v))
191#define atomic64_dec(v)			atomic64_sub(1LL, (v))
192#define atomic64_dec_return(v)		atomic64_sub_return(1LL, (v))
193#define atomic64_dec_and_test(v)	(atomic64_dec_return((v)) == 0)
194#define atomic64_inc_not_zero(v)	atomic64_add_unless((v), 1LL, 0LL)
195
196
197#endif /* !__ASSEMBLY__ */
198
199/*
200 * Internal definitions only beyond this point.
201 */
202
203/*
204 * Number of atomic locks in atomic_locks[]. Must be a power of two.
205 * There is no reason for more than PAGE_SIZE / 8 entries, since that
206 * is the maximum number of pointer bits we can use to index this.
207 * And we cannot have more than PAGE_SIZE / 4, since this has to
208 * fit on a single page and each entry takes 4 bytes.
209 */
210#define ATOMIC_HASH_SHIFT (PAGE_SHIFT - 3)
211#define ATOMIC_HASH_SIZE (1 << ATOMIC_HASH_SHIFT)
212
213#ifndef __ASSEMBLY__
214extern int atomic_locks[];
215#endif
216
217/*
218 * All the code that may fault while holding an atomic lock must
219 * place the pointer to the lock in ATOMIC_LOCK_REG so the fault code
220 * can correctly release and reacquire the lock.  Note that we
221 * mention the register number in a comment in "lib/atomic_asm.S" to help
222 * assembly coders from using this register by mistake, so if it
223 * is changed here, change that comment as well.
224 */
225#define ATOMIC_LOCK_REG 20
226#define ATOMIC_LOCK_REG_NAME r20
227
228#ifndef __ASSEMBLY__
229/* Called from setup to initialize a hash table to point to per_cpu locks. */
230void __init_atomic_per_cpu(void);
231
232#ifdef CONFIG_SMP
233/* Support releasing the atomic lock in do_page_fault_ics(). */
234void __atomic_fault_unlock(int *lock_ptr);
235#endif
236
237/* Return a pointer to the lock for the given address. */
238int *__atomic_hashed_lock(volatile void *v);
239
240/* Private helper routines in lib/atomic_asm_32.S */
241struct __get_user {
242	unsigned long val;
243	int err;
244};
245extern struct __get_user __atomic_cmpxchg(volatile int *p,
246					  int *lock, int o, int n);
247extern struct __get_user __atomic_xchg(volatile int *p, int *lock, int n);
248extern struct __get_user __atomic_xchg_add(volatile int *p, int *lock, int n);
249extern struct __get_user __atomic_xchg_add_unless(volatile int *p,
250						  int *lock, int o, int n);
251extern struct __get_user __atomic_or(volatile int *p, int *lock, int n);
252extern struct __get_user __atomic_and(volatile int *p, int *lock, int n);
253extern struct __get_user __atomic_andn(volatile int *p, int *lock, int n);
254extern struct __get_user __atomic_xor(volatile int *p, int *lock, int n);
255extern long long __atomic64_cmpxchg(volatile long long *p, int *lock,
256					long long o, long long n);
257extern long long __atomic64_xchg(volatile long long *p, int *lock, long long n);
258extern long long __atomic64_xchg_add(volatile long long *p, int *lock,
259					long long n);
260extern long long __atomic64_xchg_add_unless(volatile long long *p,
261					int *lock, long long o, long long n);
262extern long long __atomic64_and(volatile long long *p, int *lock, long long n);
263extern long long __atomic64_or(volatile long long *p, int *lock, long long n);
264extern long long __atomic64_xor(volatile long long *p, int *lock, long long n);
265
266/* Return failure from the atomic wrappers. */
267struct __get_user __atomic_bad_address(int __user *addr);
268
269#endif /* !__ASSEMBLY__ */
270
271#endif /* _ASM_TILE_ATOMIC_32_H */