mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
synced 2024-12-28 11:18:45 +07:00
62e8a3258b
This patch makes sure that atomic_{read,set}() are at least {READ,WRITE}_ONCE(). We already had the 'requirement' that atomic_read() should use ACCESS_ONCE(), and most archs had this, but a few were lacking. All are now converted to use READ_ONCE(). And, by a symmetry and general paranoia argument, upgrade atomic_set() to use WRITE_ONCE(). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Dmitry Vyukov <dvyukov@google.com> 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: james.hogan@imgtec.com Cc: linux-kernel@vger.kernel.org Cc: oleg@redhat.com Cc: will.deacon@arm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
239 lines
5.3 KiB
C
239 lines
5.3 KiB
C
#ifndef _ASM_X86_ATOMIC64_64_H
|
|
#define _ASM_X86_ATOMIC64_64_H
|
|
|
|
#include <linux/types.h>
|
|
#include <asm/alternative.h>
|
|
#include <asm/cmpxchg.h>
|
|
|
|
/* The 64-bit atomic type */
|
|
|
|
#define ATOMIC64_INIT(i) { (i) }
|
|
|
|
/**
|
|
* atomic64_read - read atomic64 variable
|
|
* @v: pointer of type atomic64_t
|
|
*
|
|
* Atomically reads the value of @v.
|
|
* Doesn't imply a read memory barrier.
|
|
*/
|
|
static inline long atomic64_read(const atomic64_t *v)
|
|
{
|
|
return READ_ONCE((v)->counter);
|
|
}
|
|
|
|
/**
|
|
* atomic64_set - set atomic64 variable
|
|
* @v: pointer to type atomic64_t
|
|
* @i: required value
|
|
*
|
|
* Atomically sets the value of @v to @i.
|
|
*/
|
|
static inline void atomic64_set(atomic64_t *v, long i)
|
|
{
|
|
WRITE_ONCE(v->counter, i);
|
|
}
|
|
|
|
/**
|
|
* atomic64_add - add integer to atomic64 variable
|
|
* @i: integer value to add
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically adds @i to @v.
|
|
*/
|
|
static __always_inline void atomic64_add(long i, atomic64_t *v)
|
|
{
|
|
asm volatile(LOCK_PREFIX "addq %1,%0"
|
|
: "=m" (v->counter)
|
|
: "er" (i), "m" (v->counter));
|
|
}
|
|
|
|
/**
|
|
* atomic64_sub - subtract the atomic64 variable
|
|
* @i: integer value to subtract
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically subtracts @i from @v.
|
|
*/
|
|
static inline void atomic64_sub(long i, atomic64_t *v)
|
|
{
|
|
asm volatile(LOCK_PREFIX "subq %1,%0"
|
|
: "=m" (v->counter)
|
|
: "er" (i), "m" (v->counter));
|
|
}
|
|
|
|
/**
|
|
* atomic64_sub_and_test - subtract value from variable and test result
|
|
* @i: integer value to subtract
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically subtracts @i from @v and returns
|
|
* true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
static inline int atomic64_sub_and_test(long i, atomic64_t *v)
|
|
{
|
|
GEN_BINARY_RMWcc(LOCK_PREFIX "subq", v->counter, "er", i, "%0", "e");
|
|
}
|
|
|
|
/**
|
|
* atomic64_inc - increment atomic64 variable
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically increments @v by 1.
|
|
*/
|
|
static __always_inline void atomic64_inc(atomic64_t *v)
|
|
{
|
|
asm volatile(LOCK_PREFIX "incq %0"
|
|
: "=m" (v->counter)
|
|
: "m" (v->counter));
|
|
}
|
|
|
|
/**
|
|
* atomic64_dec - decrement atomic64 variable
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically decrements @v by 1.
|
|
*/
|
|
static __always_inline void atomic64_dec(atomic64_t *v)
|
|
{
|
|
asm volatile(LOCK_PREFIX "decq %0"
|
|
: "=m" (v->counter)
|
|
: "m" (v->counter));
|
|
}
|
|
|
|
/**
|
|
* atomic64_dec_and_test - decrement and test
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically decrements @v by 1 and
|
|
* returns true if the result is 0, or false for all other
|
|
* cases.
|
|
*/
|
|
static inline int atomic64_dec_and_test(atomic64_t *v)
|
|
{
|
|
GEN_UNARY_RMWcc(LOCK_PREFIX "decq", v->counter, "%0", "e");
|
|
}
|
|
|
|
/**
|
|
* atomic64_inc_and_test - increment and test
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically increments @v by 1
|
|
* and returns true if the result is zero, or false for all
|
|
* other cases.
|
|
*/
|
|
static inline int atomic64_inc_and_test(atomic64_t *v)
|
|
{
|
|
GEN_UNARY_RMWcc(LOCK_PREFIX "incq", v->counter, "%0", "e");
|
|
}
|
|
|
|
/**
|
|
* atomic64_add_negative - add and test if negative
|
|
* @i: integer value to add
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically adds @i to @v and returns true
|
|
* if the result is negative, or false when
|
|
* result is greater than or equal to zero.
|
|
*/
|
|
static inline int atomic64_add_negative(long i, atomic64_t *v)
|
|
{
|
|
GEN_BINARY_RMWcc(LOCK_PREFIX "addq", v->counter, "er", i, "%0", "s");
|
|
}
|
|
|
|
/**
|
|
* atomic64_add_return - add and return
|
|
* @i: integer value to add
|
|
* @v: pointer to type atomic64_t
|
|
*
|
|
* Atomically adds @i to @v and returns @i + @v
|
|
*/
|
|
static __always_inline long atomic64_add_return(long i, atomic64_t *v)
|
|
{
|
|
return i + xadd(&v->counter, i);
|
|
}
|
|
|
|
static inline long atomic64_sub_return(long i, atomic64_t *v)
|
|
{
|
|
return atomic64_add_return(-i, v);
|
|
}
|
|
|
|
#define atomic64_inc_return(v) (atomic64_add_return(1, (v)))
|
|
#define atomic64_dec_return(v) (atomic64_sub_return(1, (v)))
|
|
|
|
static inline long atomic64_cmpxchg(atomic64_t *v, long old, long new)
|
|
{
|
|
return cmpxchg(&v->counter, old, new);
|
|
}
|
|
|
|
static inline long atomic64_xchg(atomic64_t *v, long new)
|
|
{
|
|
return xchg(&v->counter, new);
|
|
}
|
|
|
|
/**
|
|
* atomic64_add_unless - add unless the number is a given value
|
|
* @v: pointer of type atomic64_t
|
|
* @a: the amount to add to v...
|
|
* @u: ...unless v is equal to u.
|
|
*
|
|
* Atomically adds @a to @v, so long as it was not @u.
|
|
* Returns the old value of @v.
|
|
*/
|
|
static inline int atomic64_add_unless(atomic64_t *v, long a, long u)
|
|
{
|
|
long c, old;
|
|
c = atomic64_read(v);
|
|
for (;;) {
|
|
if (unlikely(c == (u)))
|
|
break;
|
|
old = atomic64_cmpxchg((v), c, c + (a));
|
|
if (likely(old == c))
|
|
break;
|
|
c = old;
|
|
}
|
|
return c != (u);
|
|
}
|
|
|
|
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1, 0)
|
|
|
|
/*
|
|
* atomic64_dec_if_positive - decrement by 1 if old value positive
|
|
* @v: pointer of type atomic_t
|
|
*
|
|
* The function returns the old value of *v minus 1, even if
|
|
* the atomic variable, v, was not decremented.
|
|
*/
|
|
static inline long atomic64_dec_if_positive(atomic64_t *v)
|
|
{
|
|
long c, old, dec;
|
|
c = atomic64_read(v);
|
|
for (;;) {
|
|
dec = c - 1;
|
|
if (unlikely(dec < 0))
|
|
break;
|
|
old = atomic64_cmpxchg((v), c, dec);
|
|
if (likely(old == c))
|
|
break;
|
|
c = old;
|
|
}
|
|
return dec;
|
|
}
|
|
|
|
#define ATOMIC64_OP(op) \
|
|
static inline void atomic64_##op(long i, atomic64_t *v) \
|
|
{ \
|
|
asm volatile(LOCK_PREFIX #op"q %1,%0" \
|
|
: "+m" (v->counter) \
|
|
: "er" (i) \
|
|
: "memory"); \
|
|
}
|
|
|
|
ATOMIC64_OP(and)
|
|
ATOMIC64_OP(or)
|
|
ATOMIC64_OP(xor)
|
|
|
|
#undef ATOMIC64_OP
|
|
|
|
#endif /* _ASM_X86_ATOMIC64_64_H */
|