Re: [PATCH v3 2/2] riscv: atomic: Using ARCH_ATOMIC in asm/atomic.h

From: Palmer Dabbelt
Date: Thu May 06 2021 - 02:04:14 EST


On Wed, 21 Apr 2021 05:53:46 PDT (-0700), guoren@xxxxxxxxxx wrote:
From: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>

The linux/atomic-arch-fallback.h has been there for a while, but
only x86 & arm64 support it. Let's make riscv follow the
linux/arch/* development trendy and make the codes more readable
and maintainable.

This patch also cleanup some codes:
- Add atomic_andnot_* operation
- Using amoswap.w.rl & amoswap.w.aq instructions in xchg
- Remove cmpxchg_acquire/release unnecessary optimization

Thanks. I haven't gotten the time to review this properly yet, but I don't really see any issues. Regardless, it was too late for this merge window anyway -- these sorts of things are a bit subtle and require a proper look, right at the end of the cycle things are just a bit too hectic.

I'll take a look once things calm down a bit, there's still some fixes out that I'd like to look at first.

I'm also only getting patch 2, and your lore link points to a different patch set.

Thanks!

Change in v3:
- Revert to origin atomic(64)_read/set coding style

Change in v2:
- Fixup andnot bug by Peter Zijlstra

Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
Link: https://lore.kernel.org/linux-riscv/CAK8P3a0FG3cpqBNUP7kXj3713cMUqV1WcEh-vcRnGKM00WXqxw@xxxxxxxxxxxxxx/
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
Cc: Anup Patel <anup@xxxxxxxxxxxxxx>
Cc: Palmer Dabbelt <palmerdabbelt@xxxxxxxxxx>
---

Signed-off-by: Guo Ren <guoren@xxxxxxxxxxxxxxxxx>
---
arch/riscv/include/asm/atomic.h | 216 ++++++++++++++++-----------------------
arch/riscv/include/asm/cmpxchg.h | 199 ++----------------------------------
2 files changed, 98 insertions(+), 317 deletions(-)

diff --git a/arch/riscv/include/asm/atomic.h b/arch/riscv/include/asm/atomic.h
index 400a8c8..b825bdb 100644
--- a/arch/riscv/include/asm/atomic.h
+++ b/arch/riscv/include/asm/atomic.h
@@ -8,13 +8,8 @@
#ifndef _ASM_RISCV_ATOMIC_H
#define _ASM_RISCV_ATOMIC_H

-#ifdef CONFIG_GENERIC_ATOMIC64
-# include <asm-generic/atomic64.h>
-#else
-# if (__riscv_xlen < 64)
-# error "64-bit atomics require XLEN to be at least 64"
-# endif
-#endif
+#include <linux/compiler.h>
+#include <linux/types.h>

#include <asm/cmpxchg.h>
#include <asm/barrier.h>
@@ -25,22 +20,22 @@
#define __atomic_release_fence() \
__asm__ __volatile__(RISCV_RELEASE_BARRIER "" ::: "memory");

-static __always_inline int atomic_read(const atomic_t *v)
+static __always_inline int arch_atomic_read(const atomic_t *v)
{
return READ_ONCE(v->counter);
}
-static __always_inline void atomic_set(atomic_t *v, int i)
+static __always_inline void arch_atomic_set(atomic_t *v, int i)
{
WRITE_ONCE(v->counter, i);
}

#ifndef CONFIG_GENERIC_ATOMIC64
#define ATOMIC64_INIT(i) { (i) }
-static __always_inline s64 atomic64_read(const atomic64_t *v)
+static __always_inline s64 arch_atomic64_read(const atomic64_t *v)
{
return READ_ONCE(v->counter);
}
-static __always_inline void atomic64_set(atomic64_t *v, s64 i)
+static __always_inline void arch_atomic64_set(atomic64_t *v, s64 i)
{
WRITE_ONCE(v->counter, i);
}
@@ -53,7 +48,7 @@ static __always_inline void atomic64_set(atomic64_t *v, s64 i)
*/
#define ATOMIC_OP(op, asm_op, I, asm_type, c_type, prefix) \
static __always_inline \
-void atomic##prefix##_##op(c_type i, atomic##prefix##_t *v) \
+void arch_atomic##prefix##_##op(c_type i, atomic##prefix##_t *v) \
{ \
__asm__ __volatile__ ( \
" amo" #asm_op "." #asm_type " zero, %1, %0" \
@@ -76,6 +71,12 @@ ATOMIC_OPS(sub, add, -i)
ATOMIC_OPS(and, and, i)
ATOMIC_OPS( or, or, i)
ATOMIC_OPS(xor, xor, i)
+ATOMIC_OPS(andnot, and, ~i)
+
+#define arch_atomic_andnot arch_atomic_andnot
+#ifndef CONFIG_GENERIC_ATOMIC64
+#define arch_atomic64_andnot arch_atomic64_andnot
+#endif

#undef ATOMIC_OP
#undef ATOMIC_OPS
@@ -87,7 +88,7 @@ ATOMIC_OPS(xor, xor, i)
*/
#define ATOMIC_FETCH_OP(op, asm_op, I, asm_type, c_type, prefix) \
static __always_inline \
-c_type atomic##prefix##_fetch_##op##_relaxed(c_type i, \
+c_type arch_atomic##prefix##_fetch_##op##_relaxed(c_type i, \
atomic##prefix##_t *v) \
{ \
register c_type ret; \
@@ -99,7 +100,7 @@ c_type atomic##prefix##_fetch_##op##_relaxed(c_type i, \
return ret; \
} \
static __always_inline \
-c_type atomic##prefix##_fetch_##op(c_type i, atomic##prefix##_t *v) \
+c_type arch_atomic##prefix##_fetch_##op(c_type i, atomic##prefix##_t *v)\
{ \
register c_type ret; \
__asm__ __volatile__ ( \
@@ -112,15 +113,16 @@ c_type atomic##prefix##_fetch_##op(c_type i, atomic##prefix##_t *v) \

#define ATOMIC_OP_RETURN(op, asm_op, c_op, I, asm_type, c_type, prefix) \
static __always_inline \
-c_type atomic##prefix##_##op##_return_relaxed(c_type i, \
+c_type arch_atomic##prefix##_##op##_return_relaxed(c_type i, \
atomic##prefix##_t *v) \
{ \
- return atomic##prefix##_fetch_##op##_relaxed(i, v) c_op I; \
+ return arch_atomic##prefix##_fetch_##op##_relaxed(i, v) c_op I; \
} \
static __always_inline \
-c_type atomic##prefix##_##op##_return(c_type i, atomic##prefix##_t *v) \
+c_type arch_atomic##prefix##_##op##_return(c_type i, \
+ atomic##prefix##_t *v) \
{ \
- return atomic##prefix##_fetch_##op(i, v) c_op I; \
+ return arch_atomic##prefix##_fetch_##op(i, v) c_op I; \
}

#ifdef CONFIG_GENERIC_ATOMIC64
@@ -138,26 +140,26 @@ c_type atomic##prefix##_##op##_return(c_type i, atomic##prefix##_t *v) \
ATOMIC_OPS(add, add, +, i)
ATOMIC_OPS(sub, add, +, -i)

-#define atomic_add_return_relaxed atomic_add_return_relaxed
-#define atomic_sub_return_relaxed atomic_sub_return_relaxed
-#define atomic_add_return atomic_add_return
-#define atomic_sub_return atomic_sub_return
+#define arch_atomic_add_return_relaxed arch_atomic_add_return_relaxed
+#define arch_atomic_sub_return_relaxed arch_atomic_sub_return_relaxed
+#define arch_atomic_add_return arch_atomic_add_return
+#define arch_atomic_sub_return arch_atomic_sub_return

-#define atomic_fetch_add_relaxed atomic_fetch_add_relaxed
-#define atomic_fetch_sub_relaxed atomic_fetch_sub_relaxed
-#define atomic_fetch_add atomic_fetch_add
-#define atomic_fetch_sub atomic_fetch_sub
+#define arch_atomic_fetch_add_relaxed arch_atomic_fetch_add_relaxed
+#define arch_atomic_fetch_sub_relaxed arch_atomic_fetch_sub_relaxed
+#define arch_atomic_fetch_add arch_atomic_fetch_add
+#define arch_atomic_fetch_sub arch_atomic_fetch_sub

#ifndef CONFIG_GENERIC_ATOMIC64
-#define atomic64_add_return_relaxed atomic64_add_return_relaxed
-#define atomic64_sub_return_relaxed atomic64_sub_return_relaxed
-#define atomic64_add_return atomic64_add_return
-#define atomic64_sub_return atomic64_sub_return
-
-#define atomic64_fetch_add_relaxed atomic64_fetch_add_relaxed
-#define atomic64_fetch_sub_relaxed atomic64_fetch_sub_relaxed
-#define atomic64_fetch_add atomic64_fetch_add
-#define atomic64_fetch_sub atomic64_fetch_sub
+#define arch_atomic64_add_return_relaxed arch_atomic64_add_return_relaxed
+#define arch_atomic64_sub_return_relaxed arch_atomic64_sub_return_relaxed
+#define arch_atomic64_add_return arch_atomic64_add_return
+#define arch_atomic64_sub_return arch_atomic64_sub_return
+
+#define arch_atomic64_fetch_add_relaxed arch_atomic64_fetch_add_relaxed
+#define arch_atomic64_fetch_sub_relaxed arch_atomic64_fetch_sub_relaxed
+#define arch_atomic64_fetch_add arch_atomic64_fetch_add
+#define arch_atomic64_fetch_sub arch_atomic64_fetch_sub
#endif

#undef ATOMIC_OPS
@@ -172,23 +174,28 @@ ATOMIC_OPS(sub, add, +, -i)
#endif

ATOMIC_OPS(and, and, i)
+ATOMIC_OPS(andnot, and, ~i)
ATOMIC_OPS( or, or, i)
ATOMIC_OPS(xor, xor, i)

-#define atomic_fetch_and_relaxed atomic_fetch_and_relaxed
-#define atomic_fetch_or_relaxed atomic_fetch_or_relaxed
-#define atomic_fetch_xor_relaxed atomic_fetch_xor_relaxed
-#define atomic_fetch_and atomic_fetch_and
-#define atomic_fetch_or atomic_fetch_or
-#define atomic_fetch_xor atomic_fetch_xor
+#define arch_atomic_fetch_and_relaxed arch_atomic_fetch_and_relaxed
+#define arch_atomic_fetch_andnot_relaxed arch_atomic_fetch_andnot_relaxed
+#define arch_atomic_fetch_or_relaxed arch_atomic_fetch_or_relaxed
+#define arch_atomic_fetch_xor_relaxed arch_atomic_fetch_xor_relaxed
+#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

#ifndef CONFIG_GENERIC_ATOMIC64
-#define atomic64_fetch_and_relaxed atomic64_fetch_and_relaxed
-#define atomic64_fetch_or_relaxed atomic64_fetch_or_relaxed
-#define atomic64_fetch_xor_relaxed atomic64_fetch_xor_relaxed
-#define atomic64_fetch_and atomic64_fetch_and
-#define atomic64_fetch_or atomic64_fetch_or
-#define atomic64_fetch_xor atomic64_fetch_xor
+#define arch_atomic64_fetch_and_relaxed arch_atomic64_fetch_and_relaxed
+#define arch_atomic64_fetch_andnot_relaxed arch_atomic64_fetch_andnot_relaxed
+#define arch_atomic64_fetch_or_relaxed arch_atomic64_fetch_or_relaxed
+#define arch_atomic64_fetch_xor_relaxed arch_atomic64_fetch_xor_relaxed
+#define arch_atomic64_fetch_and arch_atomic64_fetch_and
+#define arch_atomic64_fetch_andnot arch_atomic64_fetch_andnot
+#define arch_atomic64_fetch_or arch_atomic64_fetch_or
+#define arch_atomic64_fetch_xor arch_atomic64_fetch_xor
#endif

#undef ATOMIC_OPS
@@ -197,7 +204,7 @@ ATOMIC_OPS(xor, xor, i)
#undef ATOMIC_OP_RETURN

/* This is required to provide a full barrier on success. */
-static __always_inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
+static __always_inline int arch_atomic_fetch_add_unless(atomic_t *v, int a, int u)
{
int prev, rc;

@@ -214,10 +221,10 @@ static __always_inline int atomic_fetch_add_unless(atomic_t *v, int a, int u)
: "memory");
return prev;
}
-#define atomic_fetch_add_unless atomic_fetch_add_unless
+#define arch_atomic_fetch_add_unless arch_atomic_fetch_add_unless

#ifndef CONFIG_GENERIC_ATOMIC64
-static __always_inline s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
+static __always_inline s64 arch_atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u)
{
s64 prev;
long rc;
@@ -235,82 +242,10 @@ static __always_inline s64 atomic64_fetch_add_unless(atomic64_t *v, s64 a, s64 u
: "memory");
return prev;
}
-#define atomic64_fetch_add_unless atomic64_fetch_add_unless
+#define arch_atomic64_fetch_add_unless arch_atomic64_fetch_add_unless
#endif

-/*
- * atomic_{cmp,}xchg is required to have exactly the same ordering semantics as
- * {cmp,}xchg and the operations that return, so they need a full barrier.
- */
-#define ATOMIC_OP(c_t, prefix, size) \
-static __always_inline \
-c_t atomic##prefix##_xchg_relaxed(atomic##prefix##_t *v, c_t n) \
-{ \
- return __xchg_relaxed(&(v->counter), n, size); \
-} \
-static __always_inline \
-c_t atomic##prefix##_xchg_acquire(atomic##prefix##_t *v, c_t n) \
-{ \
- return __xchg_acquire(&(v->counter), n, size); \
-} \
-static __always_inline \
-c_t atomic##prefix##_xchg_release(atomic##prefix##_t *v, c_t n) \
-{ \
- return __xchg_release(&(v->counter), n, size); \
-} \
-static __always_inline \
-c_t atomic##prefix##_xchg(atomic##prefix##_t *v, c_t n) \
-{ \
- return __xchg(&(v->counter), n, size); \
-} \
-static __always_inline \
-c_t atomic##prefix##_cmpxchg_relaxed(atomic##prefix##_t *v, \
- c_t o, c_t n) \
-{ \
- return __cmpxchg_relaxed(&(v->counter), o, n, size); \
-} \
-static __always_inline \
-c_t atomic##prefix##_cmpxchg_acquire(atomic##prefix##_t *v, \
- c_t o, c_t n) \
-{ \
- return __cmpxchg_acquire(&(v->counter), o, n, size); \
-} \
-static __always_inline \
-c_t atomic##prefix##_cmpxchg_release(atomic##prefix##_t *v, \
- c_t o, c_t n) \
-{ \
- return __cmpxchg_release(&(v->counter), o, n, size); \
-} \
-static __always_inline \
-c_t atomic##prefix##_cmpxchg(atomic##prefix##_t *v, c_t o, c_t n) \
-{ \
- return __cmpxchg(&(v->counter), o, n, size); \
-}
-
-#ifdef CONFIG_GENERIC_ATOMIC64
-#define ATOMIC_OPS() \
- ATOMIC_OP(int, , 4)
-#else
-#define ATOMIC_OPS() \
- ATOMIC_OP(int, , 4) \
- ATOMIC_OP(s64, 64, 8)
-#endif
-
-ATOMIC_OPS()
-
-#define atomic_xchg_relaxed atomic_xchg_relaxed
-#define atomic_xchg_acquire atomic_xchg_acquire
-#define atomic_xchg_release atomic_xchg_release
-#define atomic_xchg atomic_xchg
-#define atomic_cmpxchg_relaxed atomic_cmpxchg_relaxed
-#define atomic_cmpxchg_acquire atomic_cmpxchg_acquire
-#define atomic_cmpxchg_release atomic_cmpxchg_release
-#define atomic_cmpxchg atomic_cmpxchg
-
-#undef ATOMIC_OPS
-#undef ATOMIC_OP
-
-static __always_inline int atomic_sub_if_positive(atomic_t *v, int offset)
+static __always_inline int arch_atomic_sub_if_positive(atomic_t *v, int offset)
{
int prev, rc;

@@ -327,11 +262,11 @@ static __always_inline int atomic_sub_if_positive(atomic_t *v, int offset)
: "memory");
return prev - offset;
}
+#define arch_atomic_dec_if_positive(v) arch_atomic_sub_if_positive(v, 1)

-#define atomic_dec_if_positive(v) atomic_sub_if_positive(v, 1)

#ifndef CONFIG_GENERIC_ATOMIC64
-static __always_inline s64 atomic64_sub_if_positive(atomic64_t *v, s64 offset)
+static __always_inline s64 arch_atomic64_sub_if_positive(atomic64_t *v, s64 offset)
{
s64 prev;
long rc;
@@ -349,8 +284,35 @@ static __always_inline s64 atomic64_sub_if_positive(atomic64_t *v, s64 offset)
: "memory");
return prev - offset;
}
+#define arch_atomic64_dec_if_positive(v) arch_atomic64_sub_if_positive(v, 1)
+#endif
+
+#define arch_atomic_xchg_relaxed(v, new) \
+ arch_xchg_relaxed(&((v)->counter), (new))
+#define arch_atomic_xchg_acquire(v, new) \
+ arch_xchg_acquire(&((v)->counter), (new))
+#define arch_atomic_xchg_release(v, new) \
+ arch_xchg_release(&((v)->counter), (new))
+#define arch_atomic_xchg(v, new) \
+ arch_xchg(&((v)->counter), (new))
+
+#define arch_atomic_cmpxchg_relaxed(v, old, new) \
+ arch_cmpxchg_relaxed(&((v)->counter), (old), (new))
+#define arch_atomic_cmpxchg_acquire(v, old, new) \
+ arch_cmpxchg_acquire(&((v)->counter), (old), (new))
+#define arch_atomic_cmpxchg_release(v, old, new) \
+ arch_cmpxchg_release(&((v)->counter), (old), (new))
+#define arch_atomic_cmpxchg(v, old, new) \
+ arch_cmpxchg(&((v)->counter), (old), (new))

-#define atomic64_dec_if_positive(v) atomic64_sub_if_positive(v, 1)
+#ifndef CONFIG_GENERIC_ATOMIC64
+#define arch_atomic64_xchg_relaxed arch_atomic_xchg_relaxed
+#define arch_atomic64_xchg arch_atomic_xchg
+
+#define arch_atomic64_cmpxchg_relaxed arch_atomic_cmpxchg_relaxed
+#define arch_atomic64_cmpxchg arch_atomic_cmpxchg
#endif

+#define ARCH_ATOMIC
+
#endif /* _ASM_RISCV_ATOMIC_H */
diff --git a/arch/riscv/include/asm/cmpxchg.h b/arch/riscv/include/asm/cmpxchg.h
index 262e5bb..16195a6 100644
--- a/arch/riscv/include/asm/cmpxchg.h
+++ b/arch/riscv/include/asm/cmpxchg.h
@@ -37,7 +37,7 @@
__ret; \
})

-#define xchg_relaxed(ptr, x) \
+#define arch_xchg_relaxed(ptr, x) \
({ \
__typeof__(*(ptr)) _x_ = (x); \
(__typeof__(*(ptr))) __xchg_relaxed((ptr), \
@@ -52,16 +52,14 @@
switch (size) { \
case 4: \
__asm__ __volatile__ ( \
- " amoswap.w %0, %2, %1\n" \
- RISCV_ACQUIRE_BARRIER \
+ " amoswap.w.aq %0, %2, %1\n" \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__ ( \
- " amoswap.d %0, %2, %1\n" \
- RISCV_ACQUIRE_BARRIER \
+ " amoswap.d.aq %0, %2, %1\n" \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
@@ -72,7 +70,7 @@
__ret; \
})

-#define xchg_acquire(ptr, x) \
+#define arch_xchg_acquire(ptr, x) \
({ \
__typeof__(*(ptr)) _x_ = (x); \
(__typeof__(*(ptr))) __xchg_acquire((ptr), \
@@ -87,16 +85,14 @@
switch (size) { \
case 4: \
__asm__ __volatile__ ( \
- RISCV_RELEASE_BARRIER \
- " amoswap.w %0, %2, %1\n" \
+ " amoswap.w.rl %0, %2, %1\n" \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
break; \
case 8: \
__asm__ __volatile__ ( \
- RISCV_RELEASE_BARRIER \
- " amoswap.d %0, %2, %1\n" \
+ " amoswap.d.rl %0, %2, %1\n" \
: "=r" (__ret), "+A" (*__ptr) \
: "r" (__new) \
: "memory"); \
@@ -107,7 +103,7 @@
__ret; \
})

-#define xchg_release(ptr, x) \
+#define arch_xchg_release(ptr, x) \
({ \
__typeof__(*(ptr)) _x_ = (x); \
(__typeof__(*(ptr))) __xchg_release((ptr), \
@@ -140,24 +136,12 @@
__ret; \
})

-#define xchg(ptr, x) \
+#define arch_xchg(ptr, x) \
({ \
__typeof__(*(ptr)) _x_ = (x); \
(__typeof__(*(ptr))) __xchg((ptr), _x_, sizeof(*(ptr))); \
})

-#define xchg32(ptr, x) \
-({ \
- BUILD_BUG_ON(sizeof(*(ptr)) != 4); \
- xchg((ptr), (x)); \
-})
-
-#define xchg64(ptr, x) \
-({ \
- BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
- xchg((ptr), (x)); \
-})
-
/*
* Atomic compare and exchange. Compare OLD with MEM, if identical,
* store NEW in MEM. Return the initial value in MEM. Success is
@@ -199,7 +183,7 @@
__ret; \
})

-#define cmpxchg_relaxed(ptr, o, n) \
+#define arch_cmpxchg_relaxed(ptr, o, n) \
({ \
__typeof__(*(ptr)) _o_ = (o); \
__typeof__(*(ptr)) _n_ = (n); \
@@ -207,169 +191,4 @@
_o_, _n_, sizeof(*(ptr))); \
})

-#define __cmpxchg_acquire(ptr, old, new, size) \
-({ \
- __typeof__(ptr) __ptr = (ptr); \
- __typeof__(*(ptr)) __old = (old); \
- __typeof__(*(ptr)) __new = (new); \
- __typeof__(*(ptr)) __ret; \
- register unsigned int __rc; \
- switch (size) { \
- case 4: \
- __asm__ __volatile__ ( \
- "0: lr.w %0, %2\n" \
- " bne %0, %z3, 1f\n" \
- " sc.w %1, %z4, %2\n" \
- " bnez %1, 0b\n" \
- RISCV_ACQUIRE_BARRIER \
- "1:\n" \
- : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
- : "rJ" ((long)__old), "rJ" (__new) \
- : "memory"); \
- break; \
- case 8: \
- __asm__ __volatile__ ( \
- "0: lr.d %0, %2\n" \
- " bne %0, %z3, 1f\n" \
- " sc.d %1, %z4, %2\n" \
- " bnez %1, 0b\n" \
- RISCV_ACQUIRE_BARRIER \
- "1:\n" \
- : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
- : "rJ" (__old), "rJ" (__new) \
- : "memory"); \
- break; \
- default: \
- BUILD_BUG(); \
- } \
- __ret; \
-})
-
-#define cmpxchg_acquire(ptr, o, n) \
-({ \
- __typeof__(*(ptr)) _o_ = (o); \
- __typeof__(*(ptr)) _n_ = (n); \
- (__typeof__(*(ptr))) __cmpxchg_acquire((ptr), \
- _o_, _n_, sizeof(*(ptr))); \
-})
-
-#define __cmpxchg_release(ptr, old, new, size) \
-({ \
- __typeof__(ptr) __ptr = (ptr); \
- __typeof__(*(ptr)) __old = (old); \
- __typeof__(*(ptr)) __new = (new); \
- __typeof__(*(ptr)) __ret; \
- register unsigned int __rc; \
- switch (size) { \
- case 4: \
- __asm__ __volatile__ ( \
- RISCV_RELEASE_BARRIER \
- "0: lr.w %0, %2\n" \
- " bne %0, %z3, 1f\n" \
- " sc.w %1, %z4, %2\n" \
- " bnez %1, 0b\n" \
- "1:\n" \
- : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
- : "rJ" ((long)__old), "rJ" (__new) \
- : "memory"); \
- break; \
- case 8: \
- __asm__ __volatile__ ( \
- RISCV_RELEASE_BARRIER \
- "0: lr.d %0, %2\n" \
- " bne %0, %z3, 1f\n" \
- " sc.d %1, %z4, %2\n" \
- " bnez %1, 0b\n" \
- "1:\n" \
- : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
- : "rJ" (__old), "rJ" (__new) \
- : "memory"); \
- break; \
- default: \
- BUILD_BUG(); \
- } \
- __ret; \
-})
-
-#define cmpxchg_release(ptr, o, n) \
-({ \
- __typeof__(*(ptr)) _o_ = (o); \
- __typeof__(*(ptr)) _n_ = (n); \
- (__typeof__(*(ptr))) __cmpxchg_release((ptr), \
- _o_, _n_, sizeof(*(ptr))); \
-})
-
-#define __cmpxchg(ptr, old, new, size) \
-({ \
- __typeof__(ptr) __ptr = (ptr); \
- __typeof__(*(ptr)) __old = (old); \
- __typeof__(*(ptr)) __new = (new); \
- __typeof__(*(ptr)) __ret; \
- register unsigned int __rc; \
- switch (size) { \
- case 4: \
- __asm__ __volatile__ ( \
- "0: lr.w %0, %2\n" \
- " bne %0, %z3, 1f\n" \
- " sc.w.rl %1, %z4, %2\n" \
- " bnez %1, 0b\n" \
- " fence rw, rw\n" \
- "1:\n" \
- : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
- : "rJ" ((long)__old), "rJ" (__new) \
- : "memory"); \
- break; \
- case 8: \
- __asm__ __volatile__ ( \
- "0: lr.d %0, %2\n" \
- " bne %0, %z3, 1f\n" \
- " sc.d.rl %1, %z4, %2\n" \
- " bnez %1, 0b\n" \
- " fence rw, rw\n" \
- "1:\n" \
- : "=&r" (__ret), "=&r" (__rc), "+A" (*__ptr) \
- : "rJ" (__old), "rJ" (__new) \
- : "memory"); \
- break; \
- default: \
- BUILD_BUG(); \
- } \
- __ret; \
-})
-
-#define cmpxchg(ptr, o, n) \
-({ \
- __typeof__(*(ptr)) _o_ = (o); \
- __typeof__(*(ptr)) _n_ = (n); \
- (__typeof__(*(ptr))) __cmpxchg((ptr), \
- _o_, _n_, sizeof(*(ptr))); \
-})
-
-#define cmpxchg_local(ptr, o, n) \
- (__cmpxchg_relaxed((ptr), (o), (n), sizeof(*(ptr))))
-
-#define cmpxchg32(ptr, o, n) \
-({ \
- BUILD_BUG_ON(sizeof(*(ptr)) != 4); \
- cmpxchg((ptr), (o), (n)); \
-})
-
-#define cmpxchg32_local(ptr, o, n) \
-({ \
- BUILD_BUG_ON(sizeof(*(ptr)) != 4); \
- cmpxchg_relaxed((ptr), (o), (n)) \
-})
-
-#define cmpxchg64(ptr, o, n) \
-({ \
- BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
- cmpxchg((ptr), (o), (n)); \
-})
-
-#define cmpxchg64_local(ptr, o, n) \
-({ \
- BUILD_BUG_ON(sizeof(*(ptr)) != 8); \
- cmpxchg_relaxed((ptr), (o), (n)); \
-})
-
#endif /* _ASM_RISCV_CMPXCHG_H */