linux-stable/arch/x86/include/asm/atomic64_32.h
Peter Zijlstra 37f8173dd8 locking/atomics: Flip fallbacks and instrumentation
Currently instrumentation of atomic primitives is done at the architecture
level, while composites or fallbacks are provided at the generic level.

The result is that there are no uninstrumented variants of the
fallbacks. Since there is now need of such variants to isolate text poke
from any form of instrumentation invert this ordering.

Doing this means moving the instrumentation into the generic code as
well as having (for now) two variants of the fallbacks.

Notes:

 - the various *cond_read* primitives are not proper fallbacks
   and got moved into linux/atomic.c. No arch_ variants are
   generated because the base primitives smp_cond_load*()
   are instrumented.

 - once all architectures are moved over to arch_atomic_ one of the
   fallback variants can be removed and some 2300 lines reclaimed.

 - atomic_{read,set}*() are no longer double-instrumented

Reported-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lkml.kernel.org/r/20200505134058.769149955@linutronix.de
2020-06-11 08:03:24 +02:00

342 lines
8.2 KiB
C

/* SPDX-License-Identifier: GPL-2.0 */
#ifndef _ASM_X86_ATOMIC64_32_H
#define _ASM_X86_ATOMIC64_32_H
#include <linux/compiler.h>
#include <linux/types.h>
//#include <asm/cmpxchg.h>
/* An 64bit atomic type */
typedef struct {
s64 __aligned(8) counter;
} atomic64_t;
#define ATOMIC64_INIT(val) { (val) }
#define __ATOMIC64_DECL(sym) void atomic64_##sym(atomic64_t *, ...)
#ifndef ATOMIC64_EXPORT
#define ATOMIC64_DECL_ONE __ATOMIC64_DECL
#else
#define ATOMIC64_DECL_ONE(sym) __ATOMIC64_DECL(sym); \
ATOMIC64_EXPORT(atomic64_##sym)
#endif
#ifdef CONFIG_X86_CMPXCHG64
#define __alternative_atomic64(f, g, out, in...) \
asm volatile("call %P[func]" \
: out : [func] "i" (atomic64_##g##_cx8), ## in)
#define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8)
#else
#define __alternative_atomic64(f, g, out, in...) \
alternative_call(atomic64_##f##_386, atomic64_##g##_cx8, \
X86_FEATURE_CX8, ASM_OUTPUT2(out), ## in)
#define ATOMIC64_DECL(sym) ATOMIC64_DECL_ONE(sym##_cx8); \
ATOMIC64_DECL_ONE(sym##_386)
ATOMIC64_DECL_ONE(add_386);
ATOMIC64_DECL_ONE(sub_386);
ATOMIC64_DECL_ONE(inc_386);
ATOMIC64_DECL_ONE(dec_386);
#endif
#define alternative_atomic64(f, out, in...) \
__alternative_atomic64(f, f, ASM_OUTPUT2(out), ## in)
ATOMIC64_DECL(read);
ATOMIC64_DECL(set);
ATOMIC64_DECL(xchg);
ATOMIC64_DECL(add_return);
ATOMIC64_DECL(sub_return);
ATOMIC64_DECL(inc_return);
ATOMIC64_DECL(dec_return);
ATOMIC64_DECL(dec_if_positive);
ATOMIC64_DECL(inc_not_zero);
ATOMIC64_DECL(add_unless);
#undef ATOMIC64_DECL
#undef ATOMIC64_DECL_ONE
#undef __ATOMIC64_DECL
#undef ATOMIC64_EXPORT
/**
* arch_atomic64_cmpxchg - cmpxchg atomic64 variable
* @v: pointer to type atomic64_t
* @o: expected value
* @n: new value
*
* Atomically sets @v to @n if it was equal to @o and returns
* the old value.
*/
static inline s64 arch_atomic64_cmpxchg(atomic64_t *v, s64 o, s64 n)
{
return arch_cmpxchg64(&v->counter, o, n);
}
#define arch_atomic64_cmpxchg arch_atomic64_cmpxchg
/**
* arch_atomic64_xchg - xchg atomic64 variable
* @v: pointer to type atomic64_t
* @n: value to assign
*
* Atomically xchgs the value of @v to @n and returns
* the old value.
*/
static inline s64 arch_atomic64_xchg(atomic64_t *v, s64 n)
{
s64 o;
unsigned high = (unsigned)(n >> 32);
unsigned low = (unsigned)n;
alternative_atomic64(xchg, "=&A" (o),
"S" (v), "b" (low), "c" (high)
: "memory");
return o;
}
#define arch_atomic64_xchg arch_atomic64_xchg
/**
* arch_atomic64_set - set atomic64 variable
* @v: pointer to type atomic64_t
* @i: value to assign
*
* Atomically sets the value of @v to @n.
*/
static inline void arch_atomic64_set(atomic64_t *v, s64 i)
{
unsigned high = (unsigned)(i >> 32);
unsigned low = (unsigned)i;
alternative_atomic64(set, /* no output */,
"S" (v), "b" (low), "c" (high)
: "eax", "edx", "memory");
}
/**
* arch_atomic64_read - read atomic64 variable
* @v: pointer to type atomic64_t
*
* Atomically reads the value of @v and returns it.
*/
static inline s64 arch_atomic64_read(const atomic64_t *v)
{
s64 r;
alternative_atomic64(read, "=&A" (r), "c" (v) : "memory");
return r;
}
/**
* arch_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 inline s64 arch_atomic64_add_return(s64 i, atomic64_t *v)
{
alternative_atomic64(add_return,
ASM_OUTPUT2("+A" (i), "+c" (v)),
ASM_NO_INPUT_CLOBBER("memory"));
return i;
}
#define arch_atomic64_add_return arch_atomic64_add_return
/*
* Other variants with different arithmetic operators:
*/
static inline s64 arch_atomic64_sub_return(s64 i, atomic64_t *v)
{
alternative_atomic64(sub_return,
ASM_OUTPUT2("+A" (i), "+c" (v)),
ASM_NO_INPUT_CLOBBER("memory"));
return i;
}
#define arch_atomic64_sub_return arch_atomic64_sub_return
static inline s64 arch_atomic64_inc_return(atomic64_t *v)
{
s64 a;
alternative_atomic64(inc_return, "=&A" (a),
"S" (v) : "memory", "ecx");
return a;
}
#define arch_atomic64_inc_return arch_atomic64_inc_return
static inline s64 arch_atomic64_dec_return(atomic64_t *v)
{
s64 a;
alternative_atomic64(dec_return, "=&A" (a),
"S" (v) : "memory", "ecx");
return a;
}
#define arch_atomic64_dec_return arch_atomic64_dec_return
/**
* arch_atomic64_add - add integer to atomic64 variable
* @i: integer value to add
* @v: pointer to type atomic64_t
*
* Atomically adds @i to @v.
*/
static inline s64 arch_atomic64_add(s64 i, atomic64_t *v)
{
__alternative_atomic64(add, add_return,
ASM_OUTPUT2("+A" (i), "+c" (v)),
ASM_NO_INPUT_CLOBBER("memory"));
return i;
}
/**
* arch_atomic64_sub - subtract the atomic64 variable
* @i: integer value to subtract
* @v: pointer to type atomic64_t
*
* Atomically subtracts @i from @v.
*/
static inline s64 arch_atomic64_sub(s64 i, atomic64_t *v)
{
__alternative_atomic64(sub, sub_return,
ASM_OUTPUT2("+A" (i), "+c" (v)),
ASM_NO_INPUT_CLOBBER("memory"));
return i;
}
/**
* arch_atomic64_inc - increment atomic64 variable
* @v: pointer to type atomic64_t
*
* Atomically increments @v by 1.
*/
static inline void arch_atomic64_inc(atomic64_t *v)
{
__alternative_atomic64(inc, inc_return, /* no output */,
"S" (v) : "memory", "eax", "ecx", "edx");
}
#define arch_atomic64_inc arch_atomic64_inc
/**
* arch_atomic64_dec - decrement atomic64 variable
* @v: pointer to type atomic64_t
*
* Atomically decrements @v by 1.
*/
static inline void arch_atomic64_dec(atomic64_t *v)
{
__alternative_atomic64(dec, dec_return, /* no output */,
"S" (v) : "memory", "eax", "ecx", "edx");
}
#define arch_atomic64_dec arch_atomic64_dec
/**
* arch_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 non-zero if the add was done, zero otherwise.
*/
static inline int arch_atomic64_add_unless(atomic64_t *v, s64 a, s64 u)
{
unsigned low = (unsigned)u;
unsigned high = (unsigned)(u >> 32);
alternative_atomic64(add_unless,
ASM_OUTPUT2("+A" (a), "+c" (low), "+D" (high)),
"S" (v) : "memory");
return (int)a;
}
#define arch_atomic64_add_unless arch_atomic64_add_unless
static inline int arch_atomic64_inc_not_zero(atomic64_t *v)
{
int r;
alternative_atomic64(inc_not_zero, "=&a" (r),
"S" (v) : "ecx", "edx", "memory");
return r;
}
#define arch_atomic64_inc_not_zero arch_atomic64_inc_not_zero
static inline s64 arch_atomic64_dec_if_positive(atomic64_t *v)
{
s64 r;
alternative_atomic64(dec_if_positive, "=&A" (r),
"S" (v) : "ecx", "memory");
return r;
}
#define arch_atomic64_dec_if_positive arch_atomic64_dec_if_positive
#undef alternative_atomic64
#undef __alternative_atomic64
static inline void arch_atomic64_and(s64 i, atomic64_t *v)
{
s64 old, c = 0;
while ((old = arch_atomic64_cmpxchg(v, c, c & i)) != c)
c = old;
}
static inline s64 arch_atomic64_fetch_and(s64 i, atomic64_t *v)
{
s64 old, c = 0;
while ((old = arch_atomic64_cmpxchg(v, c, c & i)) != c)
c = old;
return old;
}
#define arch_atomic64_fetch_and arch_atomic64_fetch_and
static inline void arch_atomic64_or(s64 i, atomic64_t *v)
{
s64 old, c = 0;
while ((old = arch_atomic64_cmpxchg(v, c, c | i)) != c)
c = old;
}
static inline s64 arch_atomic64_fetch_or(s64 i, atomic64_t *v)
{
s64 old, c = 0;
while ((old = arch_atomic64_cmpxchg(v, c, c | i)) != c)
c = old;
return old;
}
#define arch_atomic64_fetch_or arch_atomic64_fetch_or
static inline void arch_atomic64_xor(s64 i, atomic64_t *v)
{
s64 old, c = 0;
while ((old = arch_atomic64_cmpxchg(v, c, c ^ i)) != c)
c = old;
}
static inline s64 arch_atomic64_fetch_xor(s64 i, atomic64_t *v)
{
s64 old, c = 0;
while ((old = arch_atomic64_cmpxchg(v, c, c ^ i)) != c)
c = old;
return old;
}
#define arch_atomic64_fetch_xor arch_atomic64_fetch_xor
static inline s64 arch_atomic64_fetch_add(s64 i, atomic64_t *v)
{
s64 old, c = 0;
while ((old = arch_atomic64_cmpxchg(v, c, c + i)) != c)
c = old;
return old;
}
#define arch_atomic64_fetch_add arch_atomic64_fetch_add
#define arch_atomic64_fetch_sub(i, v) arch_atomic64_fetch_add(-(i), (v))
#endif /* _ASM_X86_ATOMIC64_32_H */