Commit 93c9d7f6 authored by Linus Torvalds's avatar Linus Torvalds

Merge branch 'x86-atomic-for-linus' of...

Merge branch 'x86-atomic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip

* 'x86-atomic-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip:
  x86: Fix LOCK_PREFIX_HERE for uniprocessor build
  x86, atomic64: In selftest, distinguish x86-64 from 586+
  x86-32: Fix atomic64_inc_not_zero return value convention
  lib: Fix atomic64_inc_not_zero test
  lib: Fix atomic64_add_unless return value convention
  x86-32: Fix atomic64_add_unless return value convention
  lib: Fix atomic64_add_unless test
  x86: Implement atomic[64]_dec_if_positive()
  lib: Only test atomic64_dec_if_positive on archs having it
  x86-32: Rewrite 32-bit atomic64 functions in assembly
  lib: Add self-test for atomic64_t
  x86-32: Allow UP/SMP lock replacement in cmpxchg64
  x86: Add support for lock prefix in alternatives
parents 7421a10d d9c5841e
......@@ -28,14 +28,17 @@
*/
#ifdef CONFIG_SMP
#define LOCK_PREFIX \
#define LOCK_PREFIX_HERE \
".section .smp_locks,\"a\"\n" \
".balign 4\n" \
".long 661f - .\n" /* offset */ \
".long 671f - .\n" /* offset */ \
".previous\n" \
"661:\n\tlock; "
"671:"
#define LOCK_PREFIX LOCK_PREFIX_HERE "\n\tlock; "
#else /* ! CONFIG_SMP */
#define LOCK_PREFIX_HERE ""
#define LOCK_PREFIX ""
#endif
......
......@@ -246,6 +246,29 @@ static inline int atomic_add_unless(atomic_t *v, int a, int u)
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
/*
* atomic_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 int atomic_dec_if_positive(atomic_t *v)
{
int c, old, dec;
c = atomic_read(v);
for (;;) {
dec = c - 1;
if (unlikely(dec < 0))
break;
old = atomic_cmpxchg((v), c, dec);
if (likely(old == c))
break;
c = old;
}
return dec;
}
/**
* atomic_inc_short - increment of a short integer
* @v: pointer to type int
......
......@@ -14,109 +14,193 @@ typedef struct {
#define ATOMIC64_INIT(val) { (val) }
extern u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val);
#ifdef CONFIG_X86_CMPXCHG64
#define ATOMIC64_ALTERNATIVE_(f, g) "call atomic64_" #g "_cx8"
#else
#define ATOMIC64_ALTERNATIVE_(f, g) ALTERNATIVE("call atomic64_" #f "_386", "call atomic64_" #g "_cx8", X86_FEATURE_CX8)
#endif
#define ATOMIC64_ALTERNATIVE(f) ATOMIC64_ALTERNATIVE_(f, f)
/**
* atomic64_cmpxchg - cmpxchg atomic64 variable
* @p: 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 long long atomic64_cmpxchg(atomic64_t *v, long long o, long long n)
{
return cmpxchg64(&v->counter, o, n);
}
/**
* atomic64_xchg - xchg atomic64 variable
* @ptr: pointer to type atomic64_t
* @new_val: value to assign
* @v: pointer to type atomic64_t
* @n: value to assign
*
* Atomically xchgs the value of @ptr to @new_val and returns
* Atomically xchgs the value of @v to @n and returns
* the old value.
*/
extern u64 atomic64_xchg(atomic64_t *ptr, u64 new_val);
static inline long long atomic64_xchg(atomic64_t *v, long long n)
{
long long o;
unsigned high = (unsigned)(n >> 32);
unsigned low = (unsigned)n;
asm volatile(ATOMIC64_ALTERNATIVE(xchg)
: "=A" (o), "+b" (low), "+c" (high)
: "S" (v)
: "memory"
);
return o;
}
/**
* atomic64_set - set atomic64 variable
* @ptr: pointer to type atomic64_t
* @new_val: value to assign
* @v: pointer to type atomic64_t
* @n: value to assign
*
* Atomically sets the value of @ptr to @new_val.
* Atomically sets the value of @v to @n.
*/
extern void atomic64_set(atomic64_t *ptr, u64 new_val);
static inline void atomic64_set(atomic64_t *v, long long i)
{
unsigned high = (unsigned)(i >> 32);
unsigned low = (unsigned)i;
asm volatile(ATOMIC64_ALTERNATIVE(set)
: "+b" (low), "+c" (high)
: "S" (v)
: "eax", "edx", "memory"
);
}
/**
* atomic64_read - read atomic64 variable
* @ptr: pointer to type atomic64_t
* @v: pointer to type atomic64_t
*
* Atomically reads the value of @ptr and returns it.
* Atomically reads the value of @v and returns it.
*/
static inline u64 atomic64_read(atomic64_t *ptr)
static inline long long atomic64_read(atomic64_t *v)
{
u64 res;
/*
* Note, we inline this atomic64_t primitive because
* it only clobbers EAX/EDX and leaves the others
* untouched. We also (somewhat subtly) rely on the
* fact that cmpxchg8b returns the current 64-bit value
* of the memory location we are touching:
*/
asm volatile(
"mov %%ebx, %%eax\n\t"
"mov %%ecx, %%edx\n\t"
LOCK_PREFIX "cmpxchg8b %1\n"
: "=&A" (res)
: "m" (*ptr)
);
return res;
}
extern u64 atomic64_read(atomic64_t *ptr);
long long r;
asm volatile(ATOMIC64_ALTERNATIVE(read)
: "=A" (r), "+c" (v)
: : "memory"
);
return r;
}
/**
* atomic64_add_return - add and return
* @delta: integer value to add
* @ptr: pointer to type atomic64_t
* @i: integer value to add
* @v: pointer to type atomic64_t
*
* Atomically adds @delta to @ptr and returns @delta + *@ptr
* Atomically adds @i to @v and returns @i + *@v
*/
extern u64 atomic64_add_return(u64 delta, atomic64_t *ptr);
static inline long long atomic64_add_return(long long i, atomic64_t *v)
{
asm volatile(ATOMIC64_ALTERNATIVE(add_return)
: "+A" (i), "+c" (v)
: : "memory"
);
return i;
}
/*
* Other variants with different arithmetic operators:
*/
extern u64 atomic64_sub_return(u64 delta, atomic64_t *ptr);
extern u64 atomic64_inc_return(atomic64_t *ptr);
extern u64 atomic64_dec_return(atomic64_t *ptr);
static inline long long atomic64_sub_return(long long i, atomic64_t *v)
{
asm volatile(ATOMIC64_ALTERNATIVE(sub_return)
: "+A" (i), "+c" (v)
: : "memory"
);
return i;
}
static inline long long atomic64_inc_return(atomic64_t *v)
{
long long a;
asm volatile(ATOMIC64_ALTERNATIVE(inc_return)
: "=A" (a)
: "S" (v)
: "memory", "ecx"
);
return a;
}
static inline long long atomic64_dec_return(atomic64_t *v)
{
long long a;
asm volatile(ATOMIC64_ALTERNATIVE(dec_return)
: "=A" (a)
: "S" (v)
: "memory", "ecx"
);
return a;
}
/**
* atomic64_add - add integer to atomic64 variable
* @delta: integer value to add
* @ptr: pointer to type atomic64_t
* @i: integer value to add
* @v: pointer to type atomic64_t
*
* Atomically adds @delta to @ptr.
* Atomically adds @i to @v.
*/
extern void atomic64_add(u64 delta, atomic64_t *ptr);
static inline long long atomic64_add(long long i, atomic64_t *v)
{
asm volatile(ATOMIC64_ALTERNATIVE_(add, add_return)
: "+A" (i), "+c" (v)
: : "memory"
);
return i;
}
/**
* atomic64_sub - subtract the atomic64 variable
* @delta: integer value to subtract
* @ptr: pointer to type atomic64_t
* @i: integer value to subtract
* @v: pointer to type atomic64_t
*
* Atomically subtracts @delta from @ptr.
* Atomically subtracts @i from @v.
*/
extern void atomic64_sub(u64 delta, atomic64_t *ptr);
static inline long long atomic64_sub(long long i, atomic64_t *v)
{
asm volatile(ATOMIC64_ALTERNATIVE_(sub, sub_return)
: "+A" (i), "+c" (v)
: : "memory"
);
return i;
}
/**
* atomic64_sub_and_test - subtract value from variable and test result
* @delta: integer value to subtract
* @ptr: pointer to type atomic64_t
*
* Atomically subtracts @delta from @ptr and returns
* @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.
*/
extern int atomic64_sub_and_test(u64 delta, atomic64_t *ptr);
static inline int atomic64_sub_and_test(long long i, atomic64_t *v)
{
return atomic64_sub_return(i, v) == 0;
}
/**
* atomic64_inc - increment atomic64 variable
* @ptr: pointer to type atomic64_t
* @v: pointer to type atomic64_t
*
* Atomically increments @ptr by 1.
* Atomically increments @v by 1.
*/
extern void atomic64_inc(atomic64_t *ptr);
static inline void atomic64_inc(atomic64_t *v)
{
asm volatile(ATOMIC64_ALTERNATIVE_(inc, inc_return)
: : "S" (v)
: "memory", "eax", "ecx", "edx"
);
}
/**
* atomic64_dec - decrement atomic64 variable
......@@ -124,37 +208,97 @@ extern void atomic64_inc(atomic64_t *ptr);
*
* Atomically decrements @ptr by 1.
*/
extern void atomic64_dec(atomic64_t *ptr);
static inline void atomic64_dec(atomic64_t *v)
{
asm volatile(ATOMIC64_ALTERNATIVE_(dec, dec_return)
: : "S" (v)
: "memory", "eax", "ecx", "edx"
);
}
/**
* atomic64_dec_and_test - decrement and test
* @ptr: pointer to type atomic64_t
* @v: pointer to type atomic64_t
*
* Atomically decrements @ptr by 1 and
* Atomically decrements @v by 1 and
* returns true if the result is 0, or false for all other
* cases.
*/
extern int atomic64_dec_and_test(atomic64_t *ptr);
static inline int atomic64_dec_and_test(atomic64_t *v)
{
return atomic64_dec_return(v) == 0;
}
/**
* atomic64_inc_and_test - increment and test
* @ptr: pointer to type atomic64_t
* @v: pointer to type atomic64_t
*
* Atomically increments @ptr by 1
* Atomically increments @v by 1
* and returns true if the result is zero, or false for all
* other cases.
*/
extern int atomic64_inc_and_test(atomic64_t *ptr);
static inline int atomic64_inc_and_test(atomic64_t *v)
{
return atomic64_inc_return(v) == 0;
}
/**
* atomic64_add_negative - add and test if negative
* @delta: integer value to add
* @ptr: pointer to type atomic64_t
* @i: integer value to add
* @v: pointer to type atomic64_t
*
* Atomically adds @delta to @ptr and returns true
* Atomically adds @i to @v and returns true
* if the result is negative, or false when
* result is greater than or equal to zero.
*/
extern int atomic64_add_negative(u64 delta, atomic64_t *ptr);
static inline int atomic64_add_negative(long long i, atomic64_t *v)
{
return atomic64_add_return(i, v) < 0;
}
/**
* 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 @v was not @u, and zero otherwise.
*/
static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
{
unsigned low = (unsigned)u;
unsigned high = (unsigned)(u >> 32);
asm volatile(ATOMIC64_ALTERNATIVE(add_unless) "\n\t"
: "+A" (a), "+c" (v), "+S" (low), "+D" (high)
: : "memory");
return (int)a;
}
static inline int atomic64_inc_not_zero(atomic64_t *v)
{
int r;
asm volatile(ATOMIC64_ALTERNATIVE(inc_not_zero)
: "=a" (r)
: "S" (v)
: "ecx", "edx", "memory"
);
return r;
}
static inline long long atomic64_dec_if_positive(atomic64_t *v)
{
long long r;
asm volatile(ATOMIC64_ALTERNATIVE(dec_if_positive)
: "=A" (r)
: "S" (v)
: "ecx", "memory"
);
return r;
}
#undef ATOMIC64_ALTERNATIVE
#undef ATOMIC64_ALTERNATIVE_
#endif /* _ASM_X86_ATOMIC64_32_H */
......@@ -221,4 +221,27 @@ static inline int atomic64_add_unless(atomic64_t *v, long a, long 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;
}
#endif /* _ASM_X86_ATOMIC64_64_H */
......@@ -271,7 +271,8 @@ extern unsigned long long cmpxchg_486_u64(volatile void *, u64, u64);
__typeof__(*(ptr)) __ret; \
__typeof__(*(ptr)) __old = (o); \
__typeof__(*(ptr)) __new = (n); \
alternative_io("call cmpxchg8b_emu", \
alternative_io(LOCK_PREFIX_HERE \
"call cmpxchg8b_emu", \
"lock; cmpxchg8b (%%esi)" , \
X86_FEATURE_CX8, \
"=A" (__ret), \
......
......@@ -247,7 +247,8 @@ static void alternatives_smp_lock(const s32 *start, const s32 *end,
if (!*poff || ptr < text || ptr >= text_end)
continue;
/* turn DS segment override prefix into lock prefix */
text_poke(ptr, ((unsigned char []){0xf0}), 1);
if (*ptr == 0x3e)
text_poke(ptr, ((unsigned char []){0xf0}), 1);
};
mutex_unlock(&text_mutex);
}
......@@ -267,7 +268,8 @@ static void alternatives_smp_unlock(const s32 *start, const s32 *end,
if (!*poff || ptr < text || ptr >= text_end)
continue;
/* turn lock prefix into DS segment override prefix */
text_poke(ptr, ((unsigned char []){0x3E}), 1);
if (*ptr == 0xf0)
text_poke(ptr, ((unsigned char []){0x3E}), 1);
};
mutex_unlock(&text_mutex);
}
......
......@@ -26,11 +26,12 @@ obj-y += msr.o msr-reg.o msr-reg-export.o
ifeq ($(CONFIG_X86_32),y)
obj-y += atomic64_32.o
lib-y += atomic64_cx8_32.o
lib-y += checksum_32.o
lib-y += strstr_32.o
lib-y += semaphore_32.o string_32.o
ifneq ($(CONFIG_X86_CMPXCHG64),y)
lib-y += cmpxchg8b_emu.o
lib-y += cmpxchg8b_emu.o atomic64_386_32.o
endif
lib-$(CONFIG_X86_USE_3DNOW) += mmx_32.o
else
......
......@@ -6,225 +6,54 @@
#include <asm/cmpxchg.h>
#include <asm/atomic.h>
static noinline u64 cmpxchg8b(u64 *ptr, u64 old, u64 new)
{
u32 low = new;
u32 high = new >> 32;
asm volatile(
LOCK_PREFIX "cmpxchg8b %1\n"
: "+A" (old), "+m" (*ptr)
: "b" (low), "c" (high)
);
return old;
}
u64 atomic64_cmpxchg(atomic64_t *ptr, u64 old_val, u64 new_val)
{
return cmpxchg8b(&ptr->counter, old_val, new_val);
}
EXPORT_SYMBOL(atomic64_cmpxchg);
/**
* atomic64_xchg - xchg atomic64 variable
* @ptr: pointer to type atomic64_t
* @new_val: value to assign
*
* Atomically xchgs the value of @ptr to @new_val and returns
* the old value.
*/
u64 atomic64_xchg(atomic64_t *ptr, u64 new_val)
{
/*
* Try first with a (possibly incorrect) assumption about
* what we have there. We'll do two loops most likely,
* but we'll get an ownership MESI transaction straight away
* instead of a read transaction followed by a
* flush-for-ownership transaction:
*/
u64 old_val, real_val = 0;
do {
old_val = real_val;
real_val = atomic64_cmpxchg(ptr, old_val, new_val);
} while (real_val != old_val);
return old_val;
}
EXPORT_SYMBOL(atomic64_xchg);
/**
* atomic64_set - set atomic64 variable
* @ptr: pointer to type atomic64_t
* @new_val: value to assign
*
* Atomically sets the value of @ptr to @new_val.
*/
void atomic64_set(atomic64_t *ptr, u64 new_val)
{
atomic64_xchg(ptr, new_val);
}
EXPORT_SYMBOL(atomic64_set);
/**
EXPORT_SYMBOL(atomic64_read);
* atomic64_add_return - add and return
* @delta: integer value to add
* @ptr: pointer to type atomic64_t
*
* Atomically adds @delta to @ptr and returns @delta + *@ptr
*/
noinline u64 atomic64_add_return(u64 delta, atomic64_t *ptr)
{
/*
* Try first with a (possibly incorrect) assumption about
* what we have there. We'll do two loops most likely,
* but we'll get an ownership MESI transaction straight away
* instead of a read transaction followed by a
* flush-for-ownership transaction:
*/
u64 old_val, new_val, real_val = 0;
do {
old_val = real_val;
new_val = old_val + delta;
real_val = atomic64_cmpxchg(ptr, old_val, new_val);
} while (real_val != old_val);
return new_val;
}
EXPORT_SYMBOL(atomic64_add_return);
u64 atomic64_sub_return(u64 delta, atomic64_t *ptr)
{
return atomic64_add_return(-delta, ptr);
}
EXPORT_SYMBOL(atomic64_sub_return);
u64 atomic64_inc_return(atomic64_t *ptr)
{
return atomic64_add_return(1, ptr);
}
EXPORT_SYMBOL(atomic64_inc_return);
u64 atomic64_dec_return(atomic64_t *ptr)
{
return atomic64_sub_return(1, ptr);
}
EXPORT_SYMBOL(atomic64_dec_return);
/**
* atomic64_add - add integer to atomic64 variable
* @delta: integer value to add
* @ptr: pointer to type atomic64_t
*
* Atomically adds @delta to @ptr.
*/
void atomic64_add(u64 delta, atomic64_t *ptr)
{
atomic64_add_return(delta, ptr);
}
EXPORT_SYMBOL(atomic64_add);
/**
* atomic64_sub - subtract the atomic64 variable
* @delta: integer value to subtract
* @ptr: pointer to type atomic64_t
*
* Atomically subtracts @delta from @ptr.
*/
void atomic64_sub(u64 delta, atomic64_t *ptr)