From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <dev-bounces@dpdk.org>
Received: from dpdk.org (dpdk.org [92.243.14.124])
	by dpdk.space (Postfix) with ESMTP id 1DF42A046B
	for <public@inbox.dpdk.org>; Mon, 24 Jun 2019 22:45:29 +0200 (CEST)
Received: from [92.243.14.124] (localhost [127.0.0.1])
	by dpdk.org (Postfix) with ESMTP id E67921BC95;
	Mon, 24 Jun 2019 22:44:59 +0200 (CEST)
Received: from mail-pf1-f196.google.com (mail-pf1-f196.google.com
 [209.85.210.196]) by dpdk.org (Postfix) with ESMTP id 2485E1BC81
 for <dev@dpdk.org>; Mon, 24 Jun 2019 22:44:50 +0200 (CEST)
Received: by mail-pf1-f196.google.com with SMTP id q10so8173630pff.9
 for <dev@dpdk.org>; Mon, 24 Jun 2019 13:44:50 -0700 (PDT)
DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=networkplumber-org.20150623.gappssmtp.com; s=20150623;
 h=from:to:cc:subject:date:message-id:in-reply-to:references
 :mime-version:content-transfer-encoding;
 bh=5jmpHlnhidg0ShQ7XItCpgaXpVK1xXtowoDpbYktXUk=;
 b=GL3Y7TILvVApPshoiWOe+0fwqEzpN45pEbaa7mUrWhV/+SYl9FJyVN4Yh//tu1MTcg
 HSi1IjqQU7ODIwM/n96cdZHJ6ZKNkLLs2/yuwD5Yj06cBwbDEQhmJeJXHuTBAwfM4Ccw
 qMx6nFgfF5K37TJOpaS5U35c912b3VdAUURhkBTyFsHICZl6eh4ihHi4ohjxMlTCDzWu
 6idYPwVNie1lYsd7VN8F/PzBjxL3X65LiRThsEvLdbmqEPXNz9TkhA4TRYuVnsAGtcFP
 cvD0/EabKIVG7mZRCAQP6lV9UNV3XK95V2s5M8FwX1k5e1fbEaHHTRFJHm/fW5cxP7HB
 b+2g==
X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed;
 d=1e100.net; s=20161025;
 h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to
 :references:mime-version:content-transfer-encoding;
 bh=5jmpHlnhidg0ShQ7XItCpgaXpVK1xXtowoDpbYktXUk=;
 b=U2IknMB0qtKXdL+SwtbpnWC3Vusb1iFvogDg9Z4uTasoleMLTXHZbGoqQpTKInq+Cy
 44vtox1xEDITEsw2ybDYOQlw9aYkOkLWK7XF1e/beZ6CfDzNPceLUfqstn1UTFcvaTyr
 EVx9r8hYcVbrqKo7fWn0Ip13hRPtokUZ3YqT9Ro2QbeRZTv2r/tosS64ZfEswkR4ecuq
 sTDvReaU9oLNxOf3AEMoM/y+WW+WYnhIaTz9ojmGGo5kGMGprm6WziYqQHCa9iZaQu9I
 As9IhVNT80p63d2pEHgwo5DKBp8Hsmtu/R3wargGWJiF6P6T5Mq7Q7RFt+jLLSLoG21m
 K/QQ==
X-Gm-Message-State: APjAAAVkpFnrZEj4abLu3KjtvXNk1s9lsAvRvU9IcaFSMJ4ZtNV1f317
 HkDUHBiV9e/kQIHyN6Duj3DlVwJMxF4=
X-Google-Smtp-Source: APXvYqxK5/bM2216QGFMAaXuEE9Uh10KOqKIl3kziFuxr4q4zbEyyuh7hAmzbGsEGElmpvPRFU3iaA==
X-Received: by 2002:a65:6210:: with SMTP id d16mr34460744pgv.180.1561409088884; 
 Mon, 24 Jun 2019 13:44:48 -0700 (PDT)
Received: from hermes.lan (204-195-22-127.wavecable.com. [204.195.22.127])
 by smtp.gmail.com with ESMTPSA id q144sm22061498pfc.103.2019.06.24.13.44.47
 (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256);
 Mon, 24 Jun 2019 13:44:48 -0700 (PDT)
From: Stephen Hemminger <stephen@networkplumber.org>
To: dev@dpdk.org
Cc: Bruce Richardson <bruce.richardson@intel.com>,
 Stephen Hemminger <stephen@networkplumber.org>,
 Andrew Rybchenko <arybchenko@solarflare.com>
Date: Mon, 24 Jun 2019 13:44:32 -0700
Message-Id: <20190624204435.29452-6-stephen@networkplumber.org>
X-Mailer: git-send-email 2.20.1
In-Reply-To: <20190624204435.29452-1-stephen@networkplumber.org>
References: <20190516180427.17270-1-stephen@networkplumber.org>
 <20190624204435.29452-1-stephen@networkplumber.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
Subject: [dpdk-dev] [PATCH v5 5/8] net/ether: mark ethernet addresses as
	being 2-byte aligned
X-BeenThere: dev@dpdk.org
X-Mailman-Version: 2.1.15
Precedence: list
List-Id: DPDK patches and discussions <dev.dpdk.org>
List-Unsubscribe: <https://mails.dpdk.org/options/dev>,
 <mailto:dev-request@dpdk.org?subject=unsubscribe>
List-Archive: <http://mails.dpdk.org/archives/dev/>
List-Post: <mailto:dev@dpdk.org>
List-Help: <mailto:dev-request@dpdk.org?subject=help>
List-Subscribe: <https://mails.dpdk.org/listinfo/dev>,
 <mailto:dev-request@dpdk.org?subject=subscribe>
Errors-To: dev-bounces@dpdk.org
Sender: "dev" <dev-bounces@dpdk.org>

From: Bruce Richardson <bruce.richardson@intel.com>

When including the rte_ether.h header in applications with warnings
enabled, a warning was given because of the assumption of 2-byte alignment
of ethernet addresses when processing them.

.../include/rte_ether.h:149:2: warning: converting a packed ‘const
  struct ether_addr’ pointer (alignment 1) to a ‘unaligned_uint16_t’
  {aka ‘const short unsigned int’} pointer (alignment 2) may result in
  an unaligned pointer value [-Waddress-of-packed-member]
149 |  const unaligned_uint16_t *ea_words = (const unaligned_uint16_t *)ea;
    |  ^~~~~

Since ethernet addresses should always be aligned on a two-byte boundary,
we can just inform the compiler of this assumption to remove the warnings
and allow us to always access the addresses using 16-bit operations.

Signed-off-by: Bruce Richardson <bruce.richardson@intel.com>
Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
---
 lib/librte_net/rte_ether.h | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

diff --git a/lib/librte_net/rte_ether.h b/lib/librte_net/rte_ether.h
index feb35a33c94b..d7b76ddf63eb 100644
--- a/lib/librte_net/rte_ether.h
+++ b/lib/librte_net/rte_ether.h
@@ -58,7 +58,8 @@ extern "C" {
  * See http://standards.ieee.org/regauth/groupmac/tutorial.html
  */
 struct rte_ether_addr {
-	uint8_t addr_bytes[RTE_ETHER_ADDR_LEN]; /**< Addr bytes in tx order */
+	uint8_t addr_bytes[RTE_ETHER_ADDR_LEN] __rte_aligned(2);
+	/**< Addr bytes in tx order */
 } __attribute__((__packed__));
 
 #define RTE_ETHER_LOCAL_ADMIN_ADDR 0x02 /**< Locally assigned Eth. address. */
@@ -81,8 +82,8 @@ struct rte_ether_addr {
 static inline int rte_is_same_ether_addr(const struct rte_ether_addr *ea1,
 				     const struct rte_ether_addr *ea2)
 {
-	const unaligned_uint16_t *w1 = (const uint16_t *)ea1;
-	const unaligned_uint16_t *w2 = (const uint16_t *)ea2;
+	const uint16_t *w1 = (const uint16_t *)ea1;
+	const uint16_t *w2 = (const uint16_t *)ea2;
 
 	return ((w1[0] ^ w2[0]) | (w1[1] ^ w2[1]) | (w1[2] ^ w2[2])) == 0;
 }
@@ -99,7 +100,7 @@ static inline int rte_is_same_ether_addr(const struct rte_ether_addr *ea1,
  */
 static inline int rte_is_zero_ether_addr(const struct rte_ether_addr *ea)
 {
-	const unaligned_uint16_t *w = (const uint16_t *)ea;
+	const uint16_t *w = (const uint16_t *)ea;
 
 	return (w[0] | w[1] | w[2]) == 0;
 }
@@ -146,7 +147,7 @@ static inline int rte_is_multicast_ether_addr(const struct rte_ether_addr *ea)
  */
 static inline int rte_is_broadcast_ether_addr(const struct rte_ether_addr *ea)
 {
-	const unaligned_uint16_t *ea_words = (const unaligned_uint16_t *)ea;
+	const uint16_t *ea_words = (const uint16_t *)ea;
 
 	return (ea_words[0] == 0xFFFF && ea_words[1] == 0xFFFF &&
 		ea_words[2] == 0xFFFF);
-- 
2.20.1