locking/atomic, arch/tile: Implement atomic{,64}_fetch_{add,sub,and,or,xor}()

Implement FETCH-OP atomic primitives, these are very similar to the
existing OP-RETURN primitives we already have, except they return the
value of the atomic variable _before_ modification.

This is especially useful for irreversible operations -- such as
bitops (because it becomes impossible to reconstruct the state prior
to modification).

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Chris Metcalf <cmetcalf@mellanox.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
This commit is contained in:
Peter Zijlstra 2016-04-18 01:16:03 +02:00 committed by Ingo Molnar
parent 3a1adb23a5
commit 1af5de9af1
6 changed files with 164 additions and 99 deletions

View File

@ -46,6 +46,10 @@ static inline int atomic_read(const atomic_t *v)
*/
#define atomic_sub_return(i, v) atomic_add_return((int)(-(i)), (v))
#define atomic_fetch_sub(i, v) atomic_fetch_add(-(int)(i), (v))
#define atomic_fetch_or atomic_fetch_or
/**
* atomic_sub - subtract integer from atomic variable
* @i: integer value to subtract

View File

@ -34,18 +34,29 @@ static inline void atomic_add(int i, atomic_t *v)
_atomic_xchg_add(&v->counter, i);
}
#define ATOMIC_OP(op) \
unsigned long _atomic_##op(volatile unsigned long *p, unsigned long mask); \
#define ATOMIC_OPS(op) \
unsigned long _atomic_fetch_##op(volatile unsigned long *p, unsigned long mask); \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
_atomic_##op((unsigned long *)&v->counter, i); \
_atomic_fetch_##op((unsigned long *)&v->counter, i); \
} \
static inline int atomic_fetch_##op(int i, atomic_t *v) \
{ \
smp_mb(); \
return _atomic_fetch_##op((unsigned long *)&v->counter, i); \
}
ATOMIC_OP(and)
ATOMIC_OP(or)
ATOMIC_OP(xor)
ATOMIC_OPS(and)
ATOMIC_OPS(or)
ATOMIC_OPS(xor)
#undef ATOMIC_OP
#undef ATOMIC_OPS
static inline int atomic_fetch_add(int i, atomic_t *v)
{
smp_mb();
return _atomic_xchg_add(&v->counter, i);
}
/**
* atomic_add_return - add integer and return
@ -126,17 +137,30 @@ static inline void atomic64_add(long long i, atomic64_t *v)
_atomic64_xchg_add(&v->counter, i);
}
#define ATOMIC64_OP(op) \
long long _atomic64_##op(long long *v, long long n); \
#define ATOMIC64_OPS(op) \
long long _atomic64_fetch_##op(long long *v, long long n); \
static inline void atomic64_##op(long long i, atomic64_t *v) \
{ \
_atomic64_##op(&v->counter, i); \
_atomic64_fetch_##op(&v->counter, i); \
} \
static inline void atomic64_##op(long long i, atomic64_t *v) \
{ \
smp_mb(); \
return _atomic64_fetch_##op(&v->counter, i); \
}
ATOMIC64_OP(and)
ATOMIC64_OP(or)
ATOMIC64_OP(xor)
#undef ATOMIC64_OPS
static inline long long atomic64_fetch_add(long long i, atomic64_t *v)
{
smp_mb();
return _atomic64_xchg_add(&v->counter, i);
}
/**
* atomic64_add_return - add integer and return
* @v: pointer of type atomic64_t
@ -186,6 +210,7 @@ static inline void atomic64_set(atomic64_t *v, long long n)
#define atomic64_inc_return(v) atomic64_add_return(1LL, (v))
#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
#define atomic64_sub_return(i, v) atomic64_add_return(-(i), (v))
#define atomic64_fetch_sub(i, v) atomic64_fetch_add(-(i), (v))
#define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0)
#define atomic64_sub(i, v) atomic64_add(-(i), (v))
#define atomic64_dec(v) atomic64_sub(1LL, (v))
@ -193,7 +218,6 @@ static inline void atomic64_set(atomic64_t *v, long long n)
#define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL)
#endif /* !__ASSEMBLY__ */
/*
@ -248,10 +272,10 @@ extern struct __get_user __atomic_xchg(volatile int *p, int *lock, int n);
extern struct __get_user __atomic_xchg_add(volatile int *p, int *lock, int n);
extern struct __get_user __atomic_xchg_add_unless(volatile int *p,
int *lock, int o, int n);
extern struct __get_user __atomic_or(volatile int *p, int *lock, int n);
extern struct __get_user __atomic_and(volatile int *p, int *lock, int n);
extern struct __get_user __atomic_andn(volatile int *p, int *lock, int n);
extern struct __get_user __atomic_xor(volatile int *p, int *lock, int n);
extern struct __get_user __atomic_fetch_or(volatile int *p, int *lock, int n);
extern struct __get_user __atomic_fetch_and(volatile int *p, int *lock, int n);
extern struct __get_user __atomic_fetch_andn(volatile int *p, int *lock, int n);
extern struct __get_user __atomic_fetch_xor(volatile int *p, int *lock, int n);
extern long long __atomic64_cmpxchg(volatile long long *p, int *lock,
long long o, long long n);
extern long long __atomic64_xchg(volatile long long *p, int *lock, long long n);
@ -259,9 +283,9 @@ extern long long __atomic64_xchg_add(volatile long long *p, int *lock,
long long n);
extern long long __atomic64_xchg_add_unless(volatile long long *p,
int *lock, long long o, long long n);
extern long long __atomic64_and(volatile long long *p, int *lock, long long n);
extern long long __atomic64_or(volatile long long *p, int *lock, long long n);
extern long long __atomic64_xor(volatile long long *p, int *lock, long long n);
extern long long __atomic64_fetch_and(volatile long long *p, int *lock, long long n);
extern long long __atomic64_fetch_or(volatile long long *p, int *lock, long long n);
extern long long __atomic64_fetch_xor(volatile long long *p, int *lock, long long n);
/* Return failure from the atomic wrappers. */
struct __get_user __atomic_bad_address(int __user *addr);

View File

@ -32,11 +32,6 @@
* on any routine which updates memory and returns a value.
*/
static inline void atomic_add(int i, atomic_t *v)
{
__insn_fetchadd4((void *)&v->counter, i);
}
/*
* Note a subtlety of the locking here. We are required to provide a
* full memory barrier before and after the operation. However, we
@ -59,28 +54,39 @@ static inline int atomic_add_return(int i, atomic_t *v)
return val;
}
static inline int __atomic_add_unless(atomic_t *v, int a, int u)
#define ATOMIC_OPS(op) \
static inline int atomic_fetch_##op(int i, atomic_t *v) \
{ \
int val; \
smp_mb(); \
val = __insn_fetch##op##4((void *)&v->counter, i); \
smp_mb(); \
return val; \
} \
static inline void atomic_##op(int i, atomic_t *v) \
{ \
__insn_fetch##op##4((void *)&v->counter, i); \
}
ATOMIC_OPS(add)
ATOMIC_OPS(and)
ATOMIC_OPS(or)
#undef ATOMIC_OPS
static inline int atomic_fetch_xor(int i, atomic_t *v)
{
int guess, oldval = v->counter;
smp_mb();
do {
if (oldval == u)
break;
guess = oldval;
oldval = cmpxchg(&v->counter, guess, guess + a);
__insn_mtspr(SPR_CMPEXCH_VALUE, guess);
oldval = __insn_cmpexch4(&v->counter, guess ^ i);
} while (guess != oldval);
smp_mb();
return oldval;
}
static inline void atomic_and(int i, atomic_t *v)
{
__insn_fetchand4((void *)&v->counter, i);
}
static inline void atomic_or(int i, atomic_t *v)
{
__insn_fetchor4((void *)&v->counter, i);
}
static inline void atomic_xor(int i, atomic_t *v)
{
int guess, oldval = v->counter;
@ -91,6 +97,18 @@ static inline void atomic_xor(int i, atomic_t *v)
} while (guess != oldval);
}
static inline int __atomic_add_unless(atomic_t *v, int a, int u)
{
int guess, oldval = v->counter;
do {
if (oldval == u)
break;
guess = oldval;
oldval = cmpxchg(&v->counter, guess, guess + a);
} while (guess != oldval);
return oldval;
}
/* Now the true 64-bit operations. */
#define ATOMIC64_INIT(i) { (i) }
@ -98,11 +116,6 @@ static inline void atomic_xor(int i, atomic_t *v)
#define atomic64_read(v) READ_ONCE((v)->counter)
#define atomic64_set(v, i) WRITE_ONCE((v)->counter, (i))
static inline void atomic64_add(long i, atomic64_t *v)
{
__insn_fetchadd((void *)&v->counter, i);
}
static inline long atomic64_add_return(long i, atomic64_t *v)
{
int val;
@ -112,6 +125,49 @@ static inline long atomic64_add_return(long i, atomic64_t *v)
return val;
}
#define ATOMIC64_OPS(op) \
static inline long atomic64_fetch_##op(long i, atomic64_t *v) \
{ \
long val; \
smp_mb(); \
val = __insn_fetch##op((void *)&v->counter, i); \
smp_mb(); \
return val; \
} \
static inline void atomic64_##op(long i, atomic64_t *v) \
{ \
__insn_fetch##op((void *)&v->counter, i); \
}
ATOMIC64_OPS(add)
ATOMIC64_OPS(and)
ATOMIC64_OPS(or)
#undef ATOMIC64_OPS
static inline long atomic64_fetch_xor(long i, atomic64_t *v)
{
long guess, oldval = v->counter;
smp_mb();
do {
guess = oldval;
__insn_mtspr(SPR_CMPEXCH_VALUE, guess);
oldval = __insn_cmpexch(&v->counter, guess ^ i);
} while (guess != oldval);
smp_mb();
return oldval;
}
static inline void atomic64_xor(long i, atomic64_t *v)
{
long guess, oldval = v->counter;
do {
guess = oldval;
__insn_mtspr(SPR_CMPEXCH_VALUE, guess);
oldval = __insn_cmpexch(&v->counter, guess ^ i);
} while (guess != oldval);
}
static inline long atomic64_add_unless(atomic64_t *v, long a, long u)
{
long guess, oldval = v->counter;
@ -124,27 +180,8 @@ static inline long atomic64_add_unless(atomic64_t *v, long a, long u)
return oldval != u;
}
static inline void atomic64_and(long i, atomic64_t *v)
{
__insn_fetchand((void *)&v->counter, i);
}
static inline void atomic64_or(long i, atomic64_t *v)
{
__insn_fetchor((void *)&v->counter, i);
}
static inline void atomic64_xor(long i, atomic64_t *v)
{
long guess, oldval = v->counter;
do {
guess = oldval;
__insn_mtspr(SPR_CMPEXCH_VALUE, guess);
oldval = __insn_cmpexch(&v->counter, guess ^ i);
} while (guess != oldval);
}
#define atomic64_sub_return(i, v) atomic64_add_return(-(i), (v))
#define atomic64_fetch_sub(i, v) atomic64_fetch_add(-(i), (v))
#define atomic64_sub(i, v) atomic64_add(-(i), (v))
#define atomic64_inc_return(v) atomic64_add_return(1, (v))
#define atomic64_dec_return(v) atomic64_sub_return(1, (v))

View File

@ -19,9 +19,9 @@
#include <asm/barrier.h>
/* Tile-specific routines to support <asm/bitops.h>. */
unsigned long _atomic_or(volatile unsigned long *p, unsigned long mask);
unsigned long _atomic_andn(volatile unsigned long *p, unsigned long mask);
unsigned long _atomic_xor(volatile unsigned long *p, unsigned long mask);
unsigned long _atomic_fetch_or(volatile unsigned long *p, unsigned long mask);
unsigned long _atomic_fetch_andn(volatile unsigned long *p, unsigned long mask);
unsigned long _atomic_fetch_xor(volatile unsigned long *p, unsigned long mask);
/**
* set_bit - Atomically set a bit in memory
@ -35,7 +35,7 @@ unsigned long _atomic_xor(volatile unsigned long *p, unsigned long mask);
*/
static inline void set_bit(unsigned nr, volatile unsigned long *addr)
{
_atomic_or(addr + BIT_WORD(nr), BIT_MASK(nr));
_atomic_fetch_or(addr + BIT_WORD(nr), BIT_MASK(nr));
}
/**
@ -54,7 +54,7 @@ static inline void set_bit(unsigned nr, volatile unsigned long *addr)
*/
static inline void clear_bit(unsigned nr, volatile unsigned long *addr)
{
_atomic_andn(addr + BIT_WORD(nr), BIT_MASK(nr));
_atomic_fetch_andn(addr + BIT_WORD(nr), BIT_MASK(nr));
}
/**
@ -69,7 +69,7 @@ static inline void clear_bit(unsigned nr, volatile unsigned long *addr)
*/
static inline void change_bit(unsigned nr, volatile unsigned long *addr)
{
_atomic_xor(addr + BIT_WORD(nr), BIT_MASK(nr));
_atomic_fetch_xor(addr + BIT_WORD(nr), BIT_MASK(nr));
}
/**
@ -85,7 +85,7 @@ static inline int test_and_set_bit(unsigned nr, volatile unsigned long *addr)
unsigned long mask = BIT_MASK(nr);
addr += BIT_WORD(nr);
smp_mb(); /* barrier for proper semantics */
return (_atomic_or(addr, mask) & mask) != 0;
return (_atomic_fetch_or(addr, mask) & mask) != 0;
}
/**
@ -101,7 +101,7 @@ static inline int test_and_clear_bit(unsigned nr, volatile unsigned long *addr)
unsigned long mask = BIT_MASK(nr);
addr += BIT_WORD(nr);
smp_mb(); /* barrier for proper semantics */
return (_atomic_andn(addr, mask) & mask) != 0;
return (_atomic_fetch_andn(addr, mask) & mask) != 0;
}
/**
@ -118,7 +118,7 @@ static inline int test_and_change_bit(unsigned nr,
unsigned long mask = BIT_MASK(nr);
addr += BIT_WORD(nr);
smp_mb(); /* barrier for proper semantics */
return (_atomic_xor(addr, mask) & mask) != 0;
return (_atomic_fetch_xor(addr, mask) & mask) != 0;
}
#include <asm-generic/bitops/ext2-atomic.h>

View File

@ -88,29 +88,29 @@ int _atomic_cmpxchg(int *v, int o, int n)
}
EXPORT_SYMBOL(_atomic_cmpxchg);
unsigned long _atomic_or(volatile unsigned long *p, unsigned long mask)
unsigned long _atomic_fetch_or(volatile unsigned long *p, unsigned long mask)
{
return __atomic_or((int *)p, __atomic_setup(p), mask).val;
return __atomic_fetch_or((int *)p, __atomic_setup(p), mask).val;
}
EXPORT_SYMBOL(_atomic_or);
EXPORT_SYMBOL(_atomic_fetch_or);
unsigned long _atomic_and(volatile unsigned long *p, unsigned long mask)
unsigned long _atomic_fetch_and(volatile unsigned long *p, unsigned long mask)
{
return __atomic_and((int *)p, __atomic_setup(p), mask).val;
return __atomic_fetch_and((int *)p, __atomic_setup(p), mask).val;
}
EXPORT_SYMBOL(_atomic_and);
EXPORT_SYMBOL(_atomic_fetch_and);
unsigned long _atomic_andn(volatile unsigned long *p, unsigned long mask)
unsigned long _atomic_fetch_andn(volatile unsigned long *p, unsigned long mask)
{
return __atomic_andn((int *)p, __atomic_setup(p), mask).val;
return __atomic_fetch_andn((int *)p, __atomic_setup(p), mask).val;
}
EXPORT_SYMBOL(_atomic_andn);
EXPORT_SYMBOL(_atomic_fetch_andn);
unsigned long _atomic_xor(volatile unsigned long *p, unsigned long mask)
unsigned long _atomic_fetch_xor(volatile unsigned long *p, unsigned long mask)
{
return __atomic_xor((int *)p, __atomic_setup(p), mask).val;
return __atomic_fetch_xor((int *)p, __atomic_setup(p), mask).val;
}
EXPORT_SYMBOL(_atomic_xor);
EXPORT_SYMBOL(_atomic_fetch_xor);
long long _atomic64_xchg(long long *v, long long n)
@ -142,23 +142,23 @@ long long _atomic64_cmpxchg(long long *v, long long o, long long n)
}
EXPORT_SYMBOL(_atomic64_cmpxchg);
long long _atomic64_and(long long *v, long long n)
long long _atomic64_fetch_and(long long *v, long long n)
{
return __atomic64_and(v, __atomic_setup(v), n);
return __atomic64_fetch_and(v, __atomic_setup(v), n);
}
EXPORT_SYMBOL(_atomic64_and);
EXPORT_SYMBOL(_atomic64_fetch_and);
long long _atomic64_or(long long *v, long long n)
long long _atomic64_fetch_or(long long *v, long long n)
{
return __atomic64_or(v, __atomic_setup(v), n);
return __atomic64_fetch_or(v, __atomic_setup(v), n);
}
EXPORT_SYMBOL(_atomic64_or);
EXPORT_SYMBOL(_atomic64_fetch_or);
long long _atomic64_xor(long long *v, long long n)
long long _atomic64_fetch_xor(long long *v, long long n)
{
return __atomic64_xor(v, __atomic_setup(v), n);
return __atomic64_fetch_xor(v, __atomic_setup(v), n);
}
EXPORT_SYMBOL(_atomic64_xor);
EXPORT_SYMBOL(_atomic64_fetch_xor);
/*
* If any of the atomic or futex routines hit a bad address (not in

View File

@ -177,10 +177,10 @@ atomic_op _xchg, 32, "move r24, r2"
atomic_op _xchg_add, 32, "add r24, r22, r2"
atomic_op _xchg_add_unless, 32, \
"sne r26, r22, r2; { bbns r26, 3f; add r24, r22, r3 }"
atomic_op _or, 32, "or r24, r22, r2"
atomic_op _and, 32, "and r24, r22, r2"
atomic_op _andn, 32, "nor r2, r2, zero; and r24, r22, r2"
atomic_op _xor, 32, "xor r24, r22, r2"
atomic_op _fetch_or, 32, "or r24, r22, r2"
atomic_op _fetch_and, 32, "and r24, r22, r2"
atomic_op _fetch_andn, 32, "nor r2, r2, zero; and r24, r22, r2"
atomic_op _fetch_xor, 32, "xor r24, r22, r2"
atomic_op 64_cmpxchg, 64, "{ seq r26, r22, r2; seq r27, r23, r3 }; \
{ bbns r26, 3f; move r24, r4 }; { bbns r27, 3f; move r25, r5 }"
@ -192,9 +192,9 @@ atomic_op 64_xchg_add_unless, 64, \
{ bbns r26, 3f; add r24, r22, r4 }; \
{ bbns r27, 3f; add r25, r23, r5 }; \
slt_u r26, r24, r22; add r25, r25, r26"
atomic_op 64_or, 64, "{ or r24, r22, r2; or r25, r23, r3 }"
atomic_op 64_and, 64, "{ and r24, r22, r2; and r25, r23, r3 }"
atomic_op 64_xor, 64, "{ xor r24, r22, r2; xor r25, r23, r3 }"
atomic_op 64_fetch_or, 64, "{ or r24, r22, r2; or r25, r23, r3 }"
atomic_op 64_fetch_and, 64, "{ and r24, r22, r2; and r25, r23, r3 }"
atomic_op 64_fetch_xor, 64, "{ xor r24, r22, r2; xor r25, r23, r3 }"
jrp lr /* happy backtracer */