Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull locking/atomics update from Thomas Gleixner:
 "The locking, atomics and memory model brains delivered:

   - A larger update to the atomics code which reworks the ordering
     barriers, consolidates the atomic primitives, provides the new
     atomic64_fetch_add_unless() primitive and cleans up the include
     hell.

   - Simplify cmpxchg() instrumentation and add instrumentation for
     xchg() and cmpxchg_double().

   - Updates to the memory model and documentation"

* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (48 commits)
  locking/atomics: Rework ordering barriers
  locking/atomics: Instrument cmpxchg_double*()
  locking/atomics: Instrument xchg()
  locking/atomics: Simplify cmpxchg() instrumentation
  locking/atomics/x86: Reduce arch_cmpxchg64*() instrumentation
  tools/memory-model: Rename litmus tests to comply to norm7
  tools/memory-model/Documentation: Fix typo, smb->smp
  sched/Documentation: Update wake_up() & co. memory-barrier guarantees
  locking/spinlock, sched/core: Clarify requirements for smp_mb__after_spinlock()
  sched/core: Use smp_mb() in wake_woken_function()
  tools/memory-model: Add informal LKMM documentation to MAINTAINERS
  locking/atomics/Documentation: Describe atomic_set() as a write operation
  tools/memory-model: Make scripts executable
  tools/memory-model: Remove ACCESS_ONCE() from model
  tools/memory-model: Remove ACCESS_ONCE() from recipes
  locking/memory-barriers.txt/kokr: Update Korean translation to fix broken DMA vs. MMIO ordering example
  MAINTAINERS: Add Daniel Lustig as an LKMM reviewer
  tools/memory-model: Fix ISA2+pooncelock+pooncelock+pombonce name
  tools/memory-model: Add litmus test for full multicopy atomicity
  locking/refcount: Always allow checked forms
  ...
This commit is contained in:
Linus Torvalds
2018-08-13 12:23:39 -07:00
77 changed files with 991 additions and 1985 deletions

View File

@@ -187,7 +187,8 @@ static inline int atomic_fetch_##op(int i, atomic_t *v) \
ATOMIC_OPS(add, +=, add)
ATOMIC_OPS(sub, -=, sub)
#define atomic_andnot atomic_andnot
#define atomic_andnot atomic_andnot
#define atomic_fetch_andnot atomic_fetch_andnot
#undef ATOMIC_OPS
#define ATOMIC_OPS(op, c_op, asm_op) \
@@ -296,8 +297,6 @@ ATOMIC_OPS(add, +=, CTOP_INST_AADD_DI_R2_R2_R3)
ATOMIC_FETCH_OP(op, c_op, asm_op)
ATOMIC_OPS(and, &=, CTOP_INST_AAND_DI_R2_R2_R3)
#define atomic_andnot(mask, v) atomic_and(~(mask), (v))
#define atomic_fetch_andnot(mask, v) atomic_fetch_and(~(mask), (v))
ATOMIC_OPS(or, |=, CTOP_INST_AOR_DI_R2_R2_R3)
ATOMIC_OPS(xor, ^=, CTOP_INST_AXOR_DI_R2_R2_R3)
@@ -308,48 +307,6 @@ ATOMIC_OPS(xor, ^=, CTOP_INST_AXOR_DI_R2_R2_R3)
#undef ATOMIC_OP_RETURN
#undef ATOMIC_OP
/**
* __atomic_add_unless - add unless the number is a given value
* @v: pointer of type atomic_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
*/
#define __atomic_add_unless(v, a, u) \
({ \
int c, old; \
\
/* \
* Explicit full memory barrier needed before/after as \
* LLOCK/SCOND thmeselves don't provide any such semantics \
*/ \
smp_mb(); \
\
c = atomic_read(v); \
while (c != (u) && (old = atomic_cmpxchg((v), c, c + (a))) != c)\
c = old; \
\
smp_mb(); \
\
c; \
})
#define atomic_inc_not_zero(v) atomic_add_unless((v), 1, 0)
#define atomic_inc(v) atomic_add(1, v)
#define atomic_dec(v) atomic_sub(1, v)
#define atomic_inc_and_test(v) (atomic_add_return(1, v) == 0)
#define atomic_dec_and_test(v) (atomic_sub_return(1, v) == 0)
#define atomic_inc_return(v) atomic_add_return(1, (v))
#define atomic_dec_return(v) atomic_sub_return(1, (v))
#define atomic_sub_and_test(i, v) (atomic_sub_return(i, v) == 0)
#define atomic_add_negative(i, v) (atomic_add_return(i, v) < 0)
#ifdef CONFIG_GENERIC_ATOMIC64
#include <asm-generic/atomic64.h>
@@ -472,7 +429,8 @@ static inline long long atomic64_fetch_##op(long long a, atomic64_t *v) \
ATOMIC64_OP_RETURN(op, op1, op2) \
ATOMIC64_FETCH_OP(op, op1, op2)
#define atomic64_andnot atomic64_andnot
#define atomic64_andnot atomic64_andnot
#define atomic64_fetch_andnot atomic64_fetch_andnot
ATOMIC64_OPS(add, add.f, adc)
ATOMIC64_OPS(sub, sub.f, sbc)
@@ -559,53 +517,43 @@ static inline long long atomic64_dec_if_positive(atomic64_t *v)
return val;
}
#define atomic64_dec_if_positive atomic64_dec_if_positive
/**
* atomic64_add_unless - add unless the number is a given value
* atomic64_fetch_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.
*
* if (v != u) { v += a; ret = 1} else {ret = 0}
* Returns 1 iff @v was not @u (i.e. if add actually happened)
* Atomically adds @a to @v, if it was not @u.
* Returns the old value of @v
*/
static inline int atomic64_add_unless(atomic64_t *v, long long a, long long u)
static inline long long atomic64_fetch_add_unless(atomic64_t *v, long long a,
long long u)
{
long long val;
int op_done;
long long old, temp;
smp_mb();
__asm__ __volatile__(
"1: llockd %0, [%2] \n"
" mov %1, 1 \n"
" brne %L0, %L4, 2f # continue to add since v != u \n"
" breq.d %H0, %H4, 3f # return since v == u \n"
" mov %1, 0 \n"
"2: \n"
" add.f %L0, %L0, %L3 \n"
" adc %H0, %H0, %H3 \n"
" scondd %0, [%2] \n"
" add.f %L1, %L0, %L3 \n"
" adc %H1, %H0, %H3 \n"
" scondd %1, [%2] \n"
" bnz 1b \n"
"3: \n"
: "=&r"(val), "=&r" (op_done)
: "=&r"(old), "=&r" (temp)
: "r"(&v->counter), "r"(a), "r"(u)
: "cc"); /* memory clobber comes from smp_mb() */
smp_mb();
return op_done;
return old;
}
#define atomic64_add_negative(a, v) (atomic64_add_return((a), (v)) < 0)
#define atomic64_inc(v) atomic64_add(1LL, (v))
#define atomic64_inc_return(v) atomic64_add_return(1LL, (v))
#define atomic64_inc_and_test(v) (atomic64_inc_return(v) == 0)
#define atomic64_sub_and_test(a, v) (atomic64_sub_return((a), (v)) == 0)
#define atomic64_dec(v) atomic64_sub(1LL, (v))
#define atomic64_dec_return(v) atomic64_sub_return(1LL, (v))
#define atomic64_dec_and_test(v) (atomic64_dec_return((v)) == 0)
#define atomic64_inc_not_zero(v) atomic64_add_unless((v), 1LL, 0LL)
#define atomic64_fetch_add_unless atomic64_fetch_add_unless
#endif /* !CONFIG_GENERIC_ATOMIC64 */