Skip to content

L
linux
Commit 2efe95fe authored by Will Deacon's avatar Will Deacon Committed by Ingo Molnar
Browse files
Options

locking/atomic, arch/arm64: Implement... 

locking/atomic, arch/arm64: Implement atomic{,64}_fetch_{add,sub,and,andnot,or,xor}{,_relaxed,_acquire,_release}() for LSE instructions

Implement FETCH-OP atomic primitives, these are very similar to the
existing OP-RETURN primitives we already have, except they return the
value of the atomic variable _before_ modification.

This is especially useful for irreversible operations -- such as
bitops (because it becomes impossible to reconstruct the state prior
to modification).

This patch implements the LSE variants.
Signed-off-by: default avatarWill Deacon <will.deacon@arm.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steve Capper <steve.capper@arm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-arch@vger.kernel.org
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Link: http://lkml.kernel.org/r/1461344493-8262-2-git-send-email-will.deacon@arm.comSigned-off-by: default avatarIngo Molnar <mingo@kernel.org>
parent 6822a84d
Hide whitespace changes
Inline Side-by-side
Showing with 172 additions and 0 deletions
arch/arm64/include/asm/atomic_lse.h
View file @ 2efe95fe
......@@ -46,6 +46,38 @@ ATOMIC_OP(add, stadd)
#undef ATOMIC_OP
#define ATOMIC_FETCH_OP(name, mb, op, asm_op, cl...) \
static inline int atomic_fetch_##op##name(int i, atomic_t *v) \
{ \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC(fetch_##op##name), \
/* LSE atomics */ \
" " #asm_op #mb " %w[i], %w[i], %[v]") \
: [i] "+r" (w0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return w0; \
}
#define ATOMIC_FETCH_OPS(op, asm_op) \
ATOMIC_FETCH_OP(_relaxed, , op, asm_op) \
ATOMIC_FETCH_OP(_acquire, a, op, asm_op, "memory") \
ATOMIC_FETCH_OP(_release, l, op, asm_op, "memory") \
ATOMIC_FETCH_OP( , al, op, asm_op, "memory")
ATOMIC_FETCH_OPS(andnot, ldclr)
ATOMIC_FETCH_OPS(or, ldset)
ATOMIC_FETCH_OPS(xor, ldeor)
ATOMIC_FETCH_OPS(add, ldadd)
#undef ATOMIC_FETCH_OP
#undef ATOMIC_FETCH_OPS
#define ATOMIC_OP_ADD_RETURN(name, mb, cl...) \
static inline int atomic_add_return##name(int i, atomic_t *v) \
{ \
......@@ -90,6 +122,33 @@ static inline void atomic_and(int i, atomic_t *v)
: __LL_SC_CLOBBERS);
}
#define ATOMIC_FETCH_OP_AND(name, mb, cl...) \
static inline int atomic_fetch_and##name(int i, atomic_t *v) \
{ \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
" nop\n" \
__LL_SC_ATOMIC(fetch_and##name), \
/* LSE atomics */ \
" mvn %w[i], %w[i]\n" \
" ldclr" #mb " %w[i], %w[i], %[v]") \
: [i] "+r" (w0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return w0; \
}
ATOMIC_FETCH_OP_AND(_relaxed, )
ATOMIC_FETCH_OP_AND(_acquire, a, "memory")
ATOMIC_FETCH_OP_AND(_release, l, "memory")
ATOMIC_FETCH_OP_AND( , al, "memory")
#undef ATOMIC_FETCH_OP_AND
static inline void atomic_sub(int i, atomic_t *v)
{
register int w0 asm ("w0") = i;
......@@ -135,6 +194,33 @@ ATOMIC_OP_SUB_RETURN(_release, l, "memory")
ATOMIC_OP_SUB_RETURN( , al, "memory")
#undef ATOMIC_OP_SUB_RETURN
#define ATOMIC_FETCH_OP_SUB(name, mb, cl...) \
static inline int atomic_fetch_sub##name(int i, atomic_t *v) \
{ \
register int w0 asm ("w0") = i; \
register atomic_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
" nop\n" \
__LL_SC_ATOMIC(fetch_sub##name), \
/* LSE atomics */ \
" neg %w[i], %w[i]\n" \
" ldadd" #mb " %w[i], %w[i], %[v]") \
: [i] "+r" (w0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return w0; \
}
ATOMIC_FETCH_OP_SUB(_relaxed, )
ATOMIC_FETCH_OP_SUB(_acquire, a, "memory")
ATOMIC_FETCH_OP_SUB(_release, l, "memory")
ATOMIC_FETCH_OP_SUB( , al, "memory")
#undef ATOMIC_FETCH_OP_SUB
#undef __LL_SC_ATOMIC
#define __LL_SC_ATOMIC64(op) __LL_SC_CALL(atomic64_##op)
......@@ -158,6 +244,38 @@ ATOMIC64_OP(add, stadd)
#undef ATOMIC64_OP
#define ATOMIC64_FETCH_OP(name, mb, op, asm_op, cl...) \
static inline long atomic64_fetch_##op##name(long i, atomic64_t *v) \
{ \
register long x0 asm ("x0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
__LL_SC_ATOMIC64(fetch_##op##name), \
/* LSE atomics */ \
" " #asm_op #mb " %[i], %[i], %[v]") \
: [i] "+r" (x0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return x0; \
}
#define ATOMIC64_FETCH_OPS(op, asm_op) \
ATOMIC64_FETCH_OP(_relaxed, , op, asm_op) \
ATOMIC64_FETCH_OP(_acquire, a, op, asm_op, "memory") \
ATOMIC64_FETCH_OP(_release, l, op, asm_op, "memory") \
ATOMIC64_FETCH_OP( , al, op, asm_op, "memory")
ATOMIC64_FETCH_OPS(andnot, ldclr)
ATOMIC64_FETCH_OPS(or, ldset)
ATOMIC64_FETCH_OPS(xor, ldeor)
ATOMIC64_FETCH_OPS(add, ldadd)
#undef ATOMIC64_FETCH_OP
#undef ATOMIC64_FETCH_OPS
#define ATOMIC64_OP_ADD_RETURN(name, mb, cl...) \
static inline long atomic64_add_return##name(long i, atomic64_t *v) \
{ \
......@@ -202,6 +320,33 @@ static inline void atomic64_and(long i, atomic64_t *v)
: __LL_SC_CLOBBERS);
}
#define ATOMIC64_FETCH_OP_AND(name, mb, cl...) \
static inline long atomic64_fetch_and##name(long i, atomic64_t *v) \
{ \
register long x0 asm ("w0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
" nop\n" \
__LL_SC_ATOMIC64(fetch_and##name), \
/* LSE atomics */ \
" mvn %[i], %[i]\n" \
" ldclr" #mb " %[i], %[i], %[v]") \
: [i] "+r" (x0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return x0; \
}
ATOMIC64_FETCH_OP_AND(_relaxed, )
ATOMIC64_FETCH_OP_AND(_acquire, a, "memory")
ATOMIC64_FETCH_OP_AND(_release, l, "memory")
ATOMIC64_FETCH_OP_AND( , al, "memory")
#undef ATOMIC64_FETCH_OP_AND
static inline void atomic64_sub(long i, atomic64_t *v)
{
register long x0 asm ("x0") = i;
......@@ -248,6 +393,33 @@ ATOMIC64_OP_SUB_RETURN( , al, "memory")
#undef ATOMIC64_OP_SUB_RETURN
#define ATOMIC64_FETCH_OP_SUB(name, mb, cl...) \
static inline long atomic64_fetch_sub##name(long i, atomic64_t *v) \
{ \
register long x0 asm ("w0") = i; \
register atomic64_t *x1 asm ("x1") = v; \
\
asm volatile(ARM64_LSE_ATOMIC_INSN( \
/* LL/SC */ \
" nop\n" \
__LL_SC_ATOMIC64(fetch_sub##name), \
/* LSE atomics */ \
" neg %[i], %[i]\n" \
" ldadd" #mb " %[i], %[i], %[v]") \
: [i] "+r" (x0), [v] "+Q" (v->counter) \
: "r" (x1) \
: __LL_SC_CLOBBERS, ##cl); \
\
return x0; \
}
ATOMIC64_FETCH_OP_SUB(_relaxed, )
ATOMIC64_FETCH_OP_SUB(_acquire, a, "memory")
ATOMIC64_FETCH_OP_SUB(_release, l, "memory")
ATOMIC64_FETCH_OP_SUB( , al, "memory")
#undef ATOMIC64_FETCH_OP_SUB
static inline long atomic64_dec_if_positive(atomic64_t *v)
{
register long x0 asm ("x0") = (long)v;
......
Markdown is supported
0% or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment
GitLab Nexedi Edition | About GitLab | About Nexedi | 沪ICP备2021021310号-2 | 沪ICP备2021021310号-7