From: David Christensen <drc@linux.vnet.ibm.com>
To: dev@dpdk.org
Cc: David Christensen <drc@linux.vnet.ibm.com>
Subject: [dpdk-dev] [PATCH] eal/ppc: replace rte_atomicXX ops with C11 atomic builtins
Date: Thu, 9 Sep 2021 12:42:43 -0700 [thread overview]
Message-ID: <20210909194243.19189-1-drc@linux.vnet.ibm.com> (raw)
Replace existing PPC assembly code for rte_atomicXX ops with compiler
atomic builtins as prevously adopted by DPDK (see [1] and [2]). This
has the additional benefit of resolving a POWER10 build failure due to an
outstanding gcc issue which fails on the existing PPC assembly code [3].
[1] https://www.dpdk.org/blog/2021/03/26/dpdk-adopts-the-c11-memory-model/
[2] https://doc.dpdk.org/guides/rel_notes/deprecation.html
[3] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98519
Signed-off-by: David Christensen <drc@linux.vnet.ibm.com>
---
lib/eal/ppc/include/rte_atomic.h | 231 +++----------------------------
1 file changed, 21 insertions(+), 210 deletions(-)
diff --git a/lib/eal/ppc/include/rte_atomic.h b/lib/eal/ppc/include/rte_atomic.h
index 6a7e65210c..86d3f9b2a1 100644
--- a/lib/eal/ppc/include/rte_atomic.h
+++ b/lib/eal/ppc/include/rte_atomic.h
@@ -1,6 +1,7 @@
/*
* SPDX-License-Identifier: BSD-3-Clause
* Inspired from FreeBSD src/sys/powerpc/include/atomic.h
+ * Copyright (c) 2021 IBM Corporation
* Copyright (c) 2008 Marcel Moolenaar
* Copyright (c) 2001 Benno Rice
* Copyright (c) 2001 David E. O'Brien
@@ -16,6 +17,7 @@ extern "C" {
#endif
#include <stdint.h>
+#include <rte_compat.h>
#include "generic/rte_atomic.h"
#define rte_mb() asm volatile("sync" : : : "memory")
@@ -43,9 +45,6 @@ rte_atomic_thread_fence(int memorder)
}
/*------------------------- 16 bit atomic operations -------------------------*/
-/* To be compatible with Power7, use GCC built-in functions for 16 bit
- * operations */
-
#ifndef RTE_FORCE_INTRINSICS
static inline int
rte_atomic16_cmpset(volatile uint16_t *dst, uint16_t exp, uint16_t src)
@@ -92,30 +91,8 @@ rte_atomic16_exchange(volatile uint16_t *dst, uint16_t val)
static inline int
rte_atomic32_cmpset(volatile uint32_t *dst, uint32_t exp, uint32_t src)
{
- unsigned int ret = 0;
-
- asm volatile(
- "\tlwsync\n"
- "1:\tlwarx %[ret], 0, %[dst]\n"
- "cmplw %[exp], %[ret]\n"
- "bne 2f\n"
- "stwcx. %[src], 0, %[dst]\n"
- "bne- 1b\n"
- "li %[ret], 1\n"
- "b 3f\n"
- "2:\n"
- "stwcx. %[ret], 0, %[dst]\n"
- "li %[ret], 0\n"
- "3:\n"
- "isync\n"
- : [ret] "=&r" (ret), "=m" (*dst)
- : [dst] "r" (dst),
- [exp] "r" (exp),
- [src] "r" (src),
- "m" (*dst)
- : "cc", "memory");
-
- return ret;
+ return __atomic_compare_exchange(dst, &exp, &src, 0, __ATOMIC_ACQUIRE,
+ __ATOMIC_ACQUIRE) ? 1 : 0;
}
static inline int rte_atomic32_test_and_set(rte_atomic32_t *v)
@@ -126,67 +103,23 @@ static inline int rte_atomic32_test_and_set(rte_atomic32_t *v)
static inline void
rte_atomic32_inc(rte_atomic32_t *v)
{
- int t;
-
- asm volatile(
- "1: lwarx %[t],0,%[cnt]\n"
- "addic %[t],%[t],1\n"
- "stwcx. %[t],0,%[cnt]\n"
- "bne- 1b\n"
- : [t] "=&r" (t), "=m" (v->cnt)
- : [cnt] "r" (&v->cnt), "m" (v->cnt)
- : "cc", "xer", "memory");
+ __atomic_add_fetch(&v->cnt, 1, __ATOMIC_ACQUIRE);
}
static inline void
rte_atomic32_dec(rte_atomic32_t *v)
{
- int t;
-
- asm volatile(
- "1: lwarx %[t],0,%[cnt]\n"
- "addic %[t],%[t],-1\n"
- "stwcx. %[t],0,%[cnt]\n"
- "bne- 1b\n"
- : [t] "=&r" (t), "=m" (v->cnt)
- : [cnt] "r" (&v->cnt), "m" (v->cnt)
- : "cc", "xer", "memory");
+ __atomic_sub_fetch(&v->cnt, 1, __ATOMIC_ACQUIRE);
}
static inline int rte_atomic32_inc_and_test(rte_atomic32_t *v)
{
- int ret;
-
- asm volatile(
- "\n\tlwsync\n"
- "1: lwarx %[ret],0,%[cnt]\n"
- "addic %[ret],%[ret],1\n"
- "stwcx. %[ret],0,%[cnt]\n"
- "bne- 1b\n"
- "isync\n"
- : [ret] "=&r" (ret)
- : [cnt] "r" (&v->cnt)
- : "cc", "xer", "memory");
-
- return ret == 0;
+ return __atomic_add_fetch(&v->cnt, 1, __ATOMIC_ACQUIRE) == 0;
}
static inline int rte_atomic32_dec_and_test(rte_atomic32_t *v)
{
- int ret;
-
- asm volatile(
- "\n\tlwsync\n"
- "1: lwarx %[ret],0,%[cnt]\n"
- "addic %[ret],%[ret],-1\n"
- "stwcx. %[ret],0,%[cnt]\n"
- "bne- 1b\n"
- "isync\n"
- : [ret] "=&r" (ret)
- : [cnt] "r" (&v->cnt)
- : "cc", "xer", "memory");
-
- return ret == 0;
+ return __atomic_sub_fetch(&v->cnt, 1, __ATOMIC_ACQUIRE) == 0;
}
static inline uint32_t
@@ -200,29 +133,8 @@ rte_atomic32_exchange(volatile uint32_t *dst, uint32_t val)
static inline int
rte_atomic64_cmpset(volatile uint64_t *dst, uint64_t exp, uint64_t src)
{
- unsigned int ret = 0;
-
- asm volatile (
- "\tlwsync\n"
- "1: ldarx %[ret], 0, %[dst]\n"
- "cmpld %[exp], %[ret]\n"
- "bne 2f\n"
- "stdcx. %[src], 0, %[dst]\n"
- "bne- 1b\n"
- "li %[ret], 1\n"
- "b 3f\n"
- "2:\n"
- "stdcx. %[ret], 0, %[dst]\n"
- "li %[ret], 0\n"
- "3:\n"
- "isync\n"
- : [ret] "=&r" (ret), "=m" (*dst)
- : [dst] "r" (dst),
- [exp] "r" (exp),
- [src] "r" (src),
- "m" (*dst)
- : "cc", "memory");
- return ret;
+ return __atomic_compare_exchange(dst, &exp, &src, 0, __ATOMIC_ACQUIRE,
+ __ATOMIC_ACQUIRE) ? 1 : 0;
}
static inline void
@@ -234,167 +146,66 @@ rte_atomic64_init(rte_atomic64_t *v)
static inline int64_t
rte_atomic64_read(rte_atomic64_t *v)
{
- long ret;
-
- asm volatile("ld%U1%X1 %[ret],%[cnt]"
- : [ret] "=r"(ret)
- : [cnt] "m"(v->cnt));
-
- return ret;
+ return v->cnt;
}
static inline void
rte_atomic64_set(rte_atomic64_t *v, int64_t new_value)
{
- asm volatile("std%U0%X0 %[new_value],%[cnt]"
- : [cnt] "=m"(v->cnt)
- : [new_value] "r"(new_value));
+ v->cnt = new_value;
}
static inline void
rte_atomic64_add(rte_atomic64_t *v, int64_t inc)
{
- long t;
-
- asm volatile(
- "1: ldarx %[t],0,%[cnt]\n"
- "add %[t],%[inc],%[t]\n"
- "stdcx. %[t],0,%[cnt]\n"
- "bne- 1b\n"
- : [t] "=&r" (t), "=m" (v->cnt)
- : [cnt] "r" (&v->cnt), [inc] "r" (inc), "m" (v->cnt)
- : "cc", "memory");
+ __atomic_add_fetch(&v->cnt, inc, __ATOMIC_ACQUIRE);
}
static inline void
rte_atomic64_sub(rte_atomic64_t *v, int64_t dec)
{
- long t;
-
- asm volatile(
- "1: ldarx %[t],0,%[cnt]\n"
- "subf %[t],%[dec],%[t]\n"
- "stdcx. %[t],0,%[cnt]\n"
- "bne- 1b\n"
- : [t] "=&r" (t), "+m" (v->cnt)
- : [cnt] "r" (&v->cnt), [dec] "r" (dec), "m" (v->cnt)
- : "cc", "memory");
+ __atomic_sub_fetch(&v->cnt, dec, __ATOMIC_ACQUIRE);
}
static inline void
rte_atomic64_inc(rte_atomic64_t *v)
{
- long t;
-
- asm volatile(
- "1: ldarx %[t],0,%[cnt]\n"
- "addic %[t],%[t],1\n"
- "stdcx. %[t],0,%[cnt]\n"
- "bne- 1b\n"
- : [t] "=&r" (t), "+m" (v->cnt)
- : [cnt] "r" (&v->cnt), "m" (v->cnt)
- : "cc", "xer", "memory");
+ __atomic_add_fetch(&v->cnt, 1, __ATOMIC_ACQUIRE);
}
static inline void
rte_atomic64_dec(rte_atomic64_t *v)
{
- long t;
-
- asm volatile(
- "1: ldarx %[t],0,%[cnt]\n"
- "addic %[t],%[t],-1\n"
- "stdcx. %[t],0,%[cnt]\n"
- "bne- 1b\n"
- : [t] "=&r" (t), "+m" (v->cnt)
- : [cnt] "r" (&v->cnt), "m" (v->cnt)
- : "cc", "xer", "memory");
+ __atomic_sub_fetch(&v->cnt, 1, __ATOMIC_ACQUIRE);
}
static inline int64_t
rte_atomic64_add_return(rte_atomic64_t *v, int64_t inc)
{
- long ret;
-
- asm volatile(
- "\n\tlwsync\n"
- "1: ldarx %[ret],0,%[cnt]\n"
- "add %[ret],%[inc],%[ret]\n"
- "stdcx. %[ret],0,%[cnt]\n"
- "bne- 1b\n"
- "isync\n"
- : [ret] "=&r" (ret)
- : [inc] "r" (inc), [cnt] "r" (&v->cnt)
- : "cc", "memory");
-
- return ret;
+ return __atomic_add_fetch(&v->cnt, inc, __ATOMIC_ACQUIRE);
}
static inline int64_t
rte_atomic64_sub_return(rte_atomic64_t *v, int64_t dec)
{
- long ret;
-
- asm volatile(
- "\n\tlwsync\n"
- "1: ldarx %[ret],0,%[cnt]\n"
- "subf %[ret],%[dec],%[ret]\n"
- "stdcx. %[ret],0,%[cnt]\n"
- "bne- 1b\n"
- "isync\n"
- : [ret] "=&r" (ret)
- : [dec] "r" (dec), [cnt] "r" (&v->cnt)
- : "cc", "memory");
-
- return ret;
+ return __atomic_sub_fetch(&v->cnt, dec, __ATOMIC_ACQUIRE);
}
static inline int rte_atomic64_inc_and_test(rte_atomic64_t *v)
{
- long ret;
-
- asm volatile(
- "\n\tlwsync\n"
- "1: ldarx %[ret],0,%[cnt]\n"
- "addic %[ret],%[ret],1\n"
- "stdcx. %[ret],0,%[cnt]\n"
- "bne- 1b\n"
- "isync\n"
- : [ret] "=&r" (ret)
- : [cnt] "r" (&v->cnt)
- : "cc", "xer", "memory");
-
- return ret == 0;
+ return __atomic_add_fetch(&v->cnt, 1, __ATOMIC_ACQUIRE) == 0;
}
static inline int rte_atomic64_dec_and_test(rte_atomic64_t *v)
{
- long ret;
-
- asm volatile(
- "\n\tlwsync\n"
- "1: ldarx %[ret],0,%[cnt]\n"
- "addic %[ret],%[ret],-1\n"
- "stdcx. %[ret],0,%[cnt]\n"
- "bne- 1b\n"
- "isync\n"
- : [ret] "=&r" (ret)
- : [cnt] "r" (&v->cnt)
- : "cc", "xer", "memory");
-
- return ret == 0;
+ return __atomic_sub_fetch(&v->cnt, 1, __ATOMIC_ACQUIRE) == 0;
}
static inline int rte_atomic64_test_and_set(rte_atomic64_t *v)
{
return rte_atomic64_cmpset((volatile uint64_t *)&v->cnt, 0, 1);
}
-/**
- * Atomically set a 64-bit counter to 0.
- *
- * @param v
- * A pointer to the atomic counter.
- */
+
static inline void rte_atomic64_clear(rte_atomic64_t *v)
{
v->cnt = 0;
--
2.27.0
next reply other threads:[~2021-09-09 19:42 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-09 19:42 David Christensen [this message]
2021-10-14 15:28 ` David Marchand
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