Commit bc6cb4d5 authored by Linus Torvalds's avatar Linus Torvalds
Browse files

Merge tag 'locking-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 

Pull locking updates from Ingo Molnar:

 - Introduce cmpxchg128() -- aka. the demise of cmpxchg_double()

   The cmpxchg128() family of functions is basically & functionally the
   same as cmpxchg_double(), but with a saner interface.

   Instead of a 6-parameter horror that forced u128 - u64/u64-halves
   layout details on the interface and exposed users to complexity,
   fragility & bugs, use a natural 3-parameter interface with u128
   types.

 - Restructure the generated atomic headers, and add kerneldoc comments
   for all of the generic atomic{,64,_long}_t operations.

   The generated definitions are much cleaner now, and come with
   documentation.

 - Implement lock_set_cmp_fn() on lockdep, for defining an ordering when
   taking multiple locks of the same type.

   This gets rid of one use of lockdep_set_novalidate_class() in the
   bcache code.

 - Fix raw_cpu_generic_try_cmpxchg() bug due to an unintended variable
   shadowing generating garbage code on Clang on certain ARM builds.

* tag 'locking-core-2023-06-27' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (43 commits)
  locking/atomic: scripts: fix ${atomic}_dec_if_positive() kerneldoc
  percpu: Fix self-assignment of __old in raw_cpu_generic_try_cmpxchg()
  locking/atomic: treewide: delete arch_atomic_*() kerneldoc
  locking/atomic: docs: Add atomic operations to the driver basic API documentation
  locking/atomic: scripts: generate kerneldoc comments
  docs: scripts: kernel-doc: accept bitwise negation like ~@var
  locking/atomic: scripts: simplify raw_atomic*() definitions
  locking/atomic: scripts: simplify raw_atomic_long*() definitions
  locking/atomic: scripts: split pfx/name/sfx/order
  locking/atomic: scripts: restructure fallback ifdeffery
  locking/atomic: scripts: build raw_atomic_long*() directly
  locking/atomic: treewide: use raw_atomic*_<op>()
  locking/atomic: scripts: add trivial raw_atomic*_<op>()
  locking/atomic: scripts: factor out order template generation
  locking/atomic: scripts: remove leftover "${mult}"
  locking/atomic: scripts: remove bogus order parameter
  locking/atomic: xtensa: add preprocessor symbols
  locking/atomic: x86: add preprocessor symbols
  locking/atomic: sparc: add preprocessor symbols
  locking/atomic: sh: add preprocessor symbols
  ...
parents ed3b7923 b33eb50a

Documentation/core-api/this_cpu_ops.rst

+0 −2
Original line number Diff line number Diff line
@@ -53,7 +53,6 @@ preemption and interrupts:: 
	this_cpu_add_return(pcp, val)

	this_cpu_xchg(pcp, nval)

	this_cpu_cmpxchg(pcp, oval, nval)

	this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)

	this_cpu_sub(pcp, val)

	this_cpu_inc(pcp)

	this_cpu_dec(pcp)
@@ -242,7 +241,6 @@ safe:: 
	__this_cpu_add_return(pcp, val)

	__this_cpu_xchg(pcp, nval)

	__this_cpu_cmpxchg(pcp, oval, nval)

	__this_cpu_cmpxchg_double(pcp1, pcp2, oval1, oval2, nval1, nval2)

	__this_cpu_sub(pcp, val)

	__this_cpu_inc(pcp)

	__this_cpu_dec(pcp)

Documentation/driver-api/basics.rst

+7 −1
Original line number Diff line number Diff line
@@ -84,7 +84,13 @@ Reference counting 
Atomics

-------



.. kernel-doc:: arch/x86/include/asm/atomic.h

.. kernel-doc:: include/linux/atomic/atomic-instrumented.h

   :internal:



.. kernel-doc:: include/linux/atomic/atomic-arch-fallback.h

   :internal:



.. kernel-doc:: include/linux/atomic/atomic-long.h

   :internal:



Kernel objects manipulation

arch/alpha/include/asm/atomic.h

+0 −35
Original line number Diff line number Diff line
@@ -200,25 +200,6 @@ ATOMIC_OPS(xor, xor) 
#undef ATOMIC_OP_RETURN

#undef ATOMIC_OP



#define arch_atomic64_cmpxchg(v, old, new) \

	(arch_cmpxchg(&((v)->counter), old, new))

#define arch_atomic64_xchg(v, new) \

	(arch_xchg(&((v)->counter), new))



#define arch_atomic_cmpxchg(v, old, new) \

	(arch_cmpxchg(&((v)->counter), old, new))

#define arch_atomic_xchg(v, new) \

	(arch_xchg(&((v)->counter), new))



/**

 * arch_atomic_fetch_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.

 */

static __inline__ int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)

{

	int c, new, old;
@@ -242,15 +223,6 @@ static __inline__ int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u) 
}

#define arch_atomic_fetch_add_unless arch_atomic_fetch_add_unless



/**

 * arch_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.

 *

 * Atomically adds @a to @v, so long as it was not @u.

 * Returns the old value of @v.

 */

static __inline__ s64 arch_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)

{

	s64 c, new, old;
@@ -274,13 +246,6 @@ static __inline__ s64 arch_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u 
}

#define arch_atomic64_fetch_add_unless arch_atomic64_fetch_add_unless



/*

 * arch_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 s64 arch_atomic64_dec_if_positive(atomic64_t *v)

{

	s64 old, tmp;

arch/arc/include/asm/atomic-spinlock.h

+9 −0
Original line number Diff line number Diff line
@@ -81,6 +81,11 @@ static inline int arch_atomic_fetch_##op(int i, atomic_t *v) \ 
ATOMIC_OPS(add, +=, add)

ATOMIC_OPS(sub, -=, sub)



#define arch_atomic_fetch_add		arch_atomic_fetch_add

#define arch_atomic_fetch_sub		arch_atomic_fetch_sub

#define arch_atomic_add_return		arch_atomic_add_return

#define arch_atomic_sub_return		arch_atomic_sub_return



#undef ATOMIC_OPS

#define ATOMIC_OPS(op, c_op, asm_op)					\

	ATOMIC_OP(op, c_op, asm_op)					\
@@ -92,7 +97,11 @@ ATOMIC_OPS(or, |=, or) 
ATOMIC_OPS(xor, ^=, xor)



#define arch_atomic_andnot		arch_atomic_andnot



#define arch_atomic_fetch_and		arch_atomic_fetch_and

#define arch_atomic_fetch_andnot	arch_atomic_fetch_andnot

#define arch_atomic_fetch_or		arch_atomic_fetch_or

#define arch_atomic_fetch_xor		arch_atomic_fetch_xor



#undef ATOMIC_OPS

#undef ATOMIC_FETCH_OP

arch/arc/include/asm/atomic.h

+0 −24
Original line number Diff line number Diff line
@@ -22,30 +22,6 @@ 
#include <asm/atomic-spinlock.h>

#endif



#define arch_atomic_cmpxchg(v, o, n)					\

({									\

	arch_cmpxchg(&((v)->counter), (o), (n));			\

})



#ifdef arch_cmpxchg_relaxed

#define arch_atomic_cmpxchg_relaxed(v, o, n)				\

({									\

	arch_cmpxchg_relaxed(&((v)->counter), (o), (n));		\

})

#endif



#define arch_atomic_xchg(v, n)						\

({									\

	arch_xchg(&((v)->counter), (n));				\

})



#ifdef arch_xchg_relaxed

#define arch_atomic_xchg_relaxed(v, n)					\

({									\

	arch_xchg_relaxed(&((v)->counter), (n));			\

})

#endif



/*

 * 64-bit atomics

 */