Re: [PATCH 12/18] locking/atomic: riscv: use s64 for atomic64

From: Palmer Dabbelt
Date: Wed May 22 2019 - 15:09:19 EST


On Wed, 22 May 2019 06:22:44 PDT (-0700), mark.rutland@xxxxxxx wrote:
As a step towards making the atomic64 API use consistent types treewide,
let's have the s390 atomic64 implementation use s64 as the underlying

and apparently the RISC-V one as well? :)

type for atomic64_t, rather than long, matching the generated headers.

As atomic64_read() depends on the generic defintion of atomic64_t, this
still returns long on 64-bit. This will be converted in a subsequent
patch.

Otherwise, there should be no functional change as a result of this patch.

Signed-off-by: Mark Rutland <mark.rutland@xxxxxxx>
Cc: Albert Ou <aou@xxxxxxxxxxxxxxxxx>
Cc: Palmer Dabbelt <palmer@xxxxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Will Deacon <will.deacon@xxxxxxx>
---
arch/riscv/include/asm/atomic.h | 44 +++++++++++++++++++++--------------------
1 file changed, 23 insertions(+), 21 deletions(-)

diff --git a/arch/riscv/include/asm/atomic.h b/arch/riscv/include/asm/atomic.h
index c9e18289d65c..bffebc57357d 100644
--- a/arch/riscv/include/asm/atomic.h
+++ b/arch/riscv/include/asm/atomic.h
@@ -42,11 +42,11 @@ static __always_inline void atomic_set(atomic_t *v, int i)

#ifndef CONFIG_GENERIC_ATOMIC64
#define ATOMIC64_INIT(i) { (i) }
-static __always_inline long atomic64_read(const atomic64_t *v)
+static __always_inline s64 atomic64_read(const atomic64_t *v)
{
return READ_ONCE(v->counter);
}
-static __always_inline void atomic64_set(atomic64_t *v, long i)
+static __always_inline void atomic64_set(atomic64_t *v, s64 i)
{
WRITE_ONCE(v->counter, i);
}
@@ -70,11 +70,11 @@ void atomic##prefix##_##op(c_type i, atomic##prefix##_t *v) \

#ifdef CONFIG_GENERIC_ATOMIC64
#define ATOMIC_OPS(op, asm_op, I) \
- ATOMIC_OP (op, asm_op, I, w, int, )
+ ATOMIC_OP (op, asm_op, I, w, int, )
#else
#define ATOMIC_OPS(op, asm_op, I) \
- ATOMIC_OP (op, asm_op, I, w, int, ) \
- ATOMIC_OP (op, asm_op, I, d, long, 64)
+ ATOMIC_OP (op, asm_op, I, w, int, ) \
+ ATOMIC_OP (op, asm_op, I, d, s64, 64)
#endif

ATOMIC_OPS(add, add, i)
@@ -131,14 +131,14 @@ c_type atomic##prefix##_##op##_return(c_type i, atomic##prefix##_t *v) \

#ifdef CONFIG_GENERIC_ATOMIC64
#define ATOMIC_OPS(op, asm_op, c_op, I) \
- ATOMIC_FETCH_OP( op, asm_op, I, w, int, ) \
- ATOMIC_OP_RETURN(op, asm_op, c_op, I, w, int, )
+ ATOMIC_FETCH_OP( op, asm_op, I, w, int, ) \
+ ATOMIC_OP_RETURN(op, asm_op, c_op, I, w, int, )
#else
#define ATOMIC_OPS(op, asm_op, c_op, I) \
- ATOMIC_FETCH_OP( op, asm_op, I, w, int, ) \
- ATOMIC_OP_RETURN(op, asm_op, c_op, I, w, int, ) \
- ATOMIC_FETCH_OP( op, asm_op, I, d, long, 64) \
- ATOMIC_OP_RETURN(op, asm_op, c_op, I, d, long, 64)
+ ATOMIC_FETCH_OP( op, asm_op, I, w, int, ) \
+ ATOMIC_OP_RETURN(op, asm_op, c_op, I, w, int, ) \
+ ATOMIC_FETCH_OP( op, asm_op, I, d, s64, 64) \
+ ATOMIC_OP_RETURN(op, asm_op, c_op, I, d, s64, 64)
#endif

ATOMIC_OPS(add, add, +, i)
@@ -170,11 +170,11 @@ ATOMIC_OPS(sub, add, +, -i)

#ifdef CONFIG_GENERIC_ATOMIC64
#define ATOMIC_OPS(op, asm_op, I) \
- ATOMIC_FETCH_OP(op, asm_op, I, w, int, )
+ ATOMIC_FETCH_OP(op, asm_op, I, w, int, )
#else
#define ATOMIC_OPS(op, asm_op, I) \
- ATOMIC_FETCH_OP(op, asm_op, I, w, int, ) \
- ATOMIC_FETCH_OP(op, asm_op, I, d, long, 64)
+ ATOMIC_FETCH_OP(op, asm_op, I, w, int, ) \
+ ATOMIC_FETCH_OP(op, asm_op, I, d, s64, 64)
#endif

ATOMIC_OPS(and, and, i)
@@ -223,9 +223,10 @@ static __always_inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
#define atomic_fetch_add_unless atomic_fetch_add_unless

#ifndef CONFIG_GENERIC_ATOMIC64
-static __always_inline long atomic64_fetch_add_unless(atomic64_t *v, long a, long u)
+static __always_inline s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
{
- long prev, rc;
+ s64 prev;
+ long rc;

__asm__ __volatile__ (
"0: lr.d %[p], %[c]\n"
@@ -294,11 +295,11 @@ c_t atomic##prefix##_cmpxchg(atomic##prefix##_t *v, c_t o, c_t n) \

#ifdef CONFIG_GENERIC_ATOMIC64
#define ATOMIC_OPS() \
- ATOMIC_OP( int, , 4)
+ ATOMIC_OP(int, , 4)
#else
#define ATOMIC_OPS() \
- ATOMIC_OP( int, , 4) \
- ATOMIC_OP(long, 64, 8)
+ ATOMIC_OP(int, , 4) \
+ ATOMIC_OP(s64, 64, 8)
#endif

ATOMIC_OPS()
@@ -336,9 +337,10 @@ static __always_inline int atomic_sub_if_positive(atomic_t *v, int offset)
#define atomic_dec_if_positive(v) atomic_sub_if_positive(v, 1)

#ifndef CONFIG_GENERIC_ATOMIC64
-static __always_inline long atomic64_sub_if_positive(atomic64_t *v, long offset)
+static __always_inline s64 atomic64_sub_if_positive(atomic64_t *v, s64 offset)
{
- long prev, rc;
+ s64 prev;
+ long rc;

__asm__ __volatile__ (
"0: lr.d %[p], %[c]\n"

Reviwed-by: Palmer Dabbelt <palmer@xxxxxxxxxx>

Thanks!