patches for DPDK stable branches
 help / color / mirror / Atom feed
From: Joyce Kong <joyce.kong@arm.com>
To: jerinj@marvell.com, david.marchand@redhat.com,
	ruifeng.wang@arm.com, honnappa.nagarahalli@arm.com
Cc: dev@dpdk.org, nd@arm.com, stable@dpdk.org
Subject: [dpdk-stable] [PATCH v1] eal/arm: fix gcc build for 128-bit atomic compare exchange
Date: Fri, 15 Jan 2021 17:58:21 +0800
Message-ID: <20210115095821.42721-1-joyce.kong@arm.com> (raw)

Compiling with "meson build -Dbuildtype=debug --cross-file
config/arm/arm64_thunderx2_linux_gcc" shows the warnings
"function returns an aggregate [-Waggregate-return]":
../../dpdk/lib/librte_eal/arm/include/rte_atomic_64.h: In
function ‘__cas_128_relaxed’:
../../dpdk/lib/librte_eal/arm/include/rte_atomic_64.h:81:20:
error: function returns an aggregate [-Werror=aggregate-return]
 __ATOMIC128_CAS_OP(__cas_128_relaxed, "casp")
                    ^~~~~~~~~~~~~~~~~

Fix the compiling issue by defining __ATOMIC128_CAS_OP as a void
function and passing the address pointer into it.

Fixes: 7e2c3e17fe2c ("eal/arm64: add 128-bit atomic compare exchange")
Cc: stable@dpdk.org

Signed-off-by: Joyce Kong <joyce.kong@arm.com>
---
 lib/librte_eal/arm/include/rte_atomic_64.h | 28 +++++++++++-----------
 1 file changed, 14 insertions(+), 14 deletions(-)

diff --git a/lib/librte_eal/arm/include/rte_atomic_64.h b/lib/librte_eal/arm/include/rte_atomic_64.h
index 467d32a45..fa6f334c0 100644
--- a/lib/librte_eal/arm/include/rte_atomic_64.h
+++ b/lib/librte_eal/arm/include/rte_atomic_64.h
@@ -53,15 +53,15 @@ rte_atomic_thread_fence(int memorder)
 #endif
 
 #define __ATOMIC128_CAS_OP(cas_op_name, op_string)                          \
-static __rte_noinline rte_int128_t                                          \
-cas_op_name(rte_int128_t *dst, rte_int128_t old, rte_int128_t updated)      \
+static __rte_noinline void                                                  \
+cas_op_name(rte_int128_t *dst, rte_int128_t *old, rte_int128_t updated)     \
 {                                                                           \
 	/* caspX instructions register pair must start from even-numbered
 	 * register at operand 1.
 	 * So, specify registers for local variables here.
 	 */                                                                 \
-	register uint64_t x0 __asm("x0") = (uint64_t)old.val[0];            \
-	register uint64_t x1 __asm("x1") = (uint64_t)old.val[1];            \
+	register uint64_t x0 __asm("x0") = (uint64_t)old->val[0];           \
+	register uint64_t x1 __asm("x1") = (uint64_t)old->val[1];           \
 	register uint64_t x2 __asm("x2") = (uint64_t)updated.val[0];        \
 	register uint64_t x3 __asm("x3") = (uint64_t)updated.val[1];        \
 	asm volatile(                                                       \
@@ -73,9 +73,8 @@ cas_op_name(rte_int128_t *dst, rte_int128_t old, rte_int128_t updated)      \
 		[upd1] "r" (x3),                                            \
 		[dst] "r" (dst)                                             \
 		: "memory");                                                \
-	old.val[0] = x0;                                                    \
-	old.val[1] = x1;                                                    \
-	return old;                                                         \
+	old->val[0] = x0;                                                   \
+	old->val[1] = x1;                                                   \
 }
 
 __ATOMIC128_CAS_OP(__cas_128_relaxed, "casp")
@@ -113,13 +112,14 @@ rte_atomic128_cmp_exchange(rte_int128_t *dst, rte_int128_t *exp,
 
 #if defined(__ARM_FEATURE_ATOMICS) || defined(RTE_ARM_FEATURE_ATOMICS)
 	if (success == __ATOMIC_RELAXED)
-		old = __cas_128_relaxed(dst, expected, desired);
+		__cas_128_relaxed(dst, exp, desired);
 	else if (success == __ATOMIC_ACQUIRE)
-		old = __cas_128_acquire(dst, expected, desired);
+		__cas_128_acquire(dst, exp, desired);
 	else if (success == __ATOMIC_RELEASE)
-		old = __cas_128_release(dst, expected, desired);
+		__cas_128_release(dst, exp, desired);
 	else
-		old = __cas_128_acq_rel(dst, expected, desired);
+		__cas_128_acq_rel(dst, exp, desired);
+	old = *exp;
 #else
 #define __HAS_ACQ(mo) ((mo) != __ATOMIC_RELAXED && (mo) != __ATOMIC_RELEASE)
 #define __HAS_RLS(mo) ((mo) == __ATOMIC_RELEASE || (mo) == __ATOMIC_ACQ_REL || \
@@ -183,12 +183,12 @@ rte_atomic128_cmp_exchange(rte_int128_t *dst, rte_int128_t *exp,
 #undef __STORE_128
 
 	} while (unlikely(ret));
-#endif
 
-	/* Unconditionally updating expected removes an 'if' statement.
-	 * expected should already be in register if not in the cache.
+	/* Unconditionally updating the value of exp removes an 'if' statement.
+	 * The value of exp should already be in register if not in the cache.
 	 */
 	*exp = old;
+#endif
 
 	return (old.int128 == expected.int128);
 }
-- 
2.30.0


             reply	other threads:[~2021-01-15  9:58 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2021-01-15  9:58 Joyce Kong [this message]
2021-01-15 15:55 ` David Marchand
2021-01-21  9:36   ` Joyce Kong
2021-01-27  3:36 ` Ruifeng Wang
2021-01-27  9:56   ` [dpdk-stable] [dpdk-dev] " Jerin Jacob
2021-01-27 10:22 ` [dpdk-stable] " David Marchand

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20210115095821.42721-1-joyce.kong@arm.com \
    --to=joyce.kong@arm.com \
    --cc=david.marchand@redhat.com \
    --cc=dev@dpdk.org \
    --cc=honnappa.nagarahalli@arm.com \
    --cc=jerinj@marvell.com \
    --cc=nd@arm.com \
    --cc=ruifeng.wang@arm.com \
    --cc=stable@dpdk.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

patches for DPDK stable branches

This inbox may be cloned and mirrored by anyone:

	git clone --mirror https://inbox.dpdk.org/stable/0 stable/git/0.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 stable stable/ https://inbox.dpdk.org/stable \
		stable@dpdk.org
	public-inbox-index stable

Example config snippet for mirrors.
Newsgroup available over NNTP:
	nntp://inbox.dpdk.org/inbox.dpdk.stable


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git