Received-SPF: pass (google.com: best guess record for domain of linux-kernel-owner@vger.kernel.org designates 209.132.180.67 as permitted sender) client-ip=209.132.180.67;
From:   Dave Rodgman <dave.rodgman@arm.com>
To:     "linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>,
        "akpm@linux-foundation.org" <akpm@linux-foundation.org>
CC:     "herbert@gondor.apana.org.au" <herbert@gondor.apana.org.au>,
        "davem@davemloft.net" <davem@davemloft.net>,
        Matt Sealey <Matt.Sealey@arm.com>,
        "nitingupta910@gmail.com" <nitingupta910@gmail.com>,
        "markus@oberhumer.com" <markus@oberhumer.com>,
        "minchan@kernel.org" <minchan@kernel.org>,
        "sergey.senozhatsky.work@gmail.com" 
        <sergey.senozhatsky.work@gmail.com>,
        "sonnyrao@google.com" <sonnyrao@google.com>,
        "gregkh@linuxfoundation.org" <gregkh@linuxfoundation.org>,
        nd <nd@arm.com>
Subject: [PATCH 3/8] lib/lzo: enable 64-bit CTZ on Arm
Thread-Topic: [PATCH 3/8] lib/lzo: enable 64-bit CTZ on Arm
Thread-Index: AQHUiKJ//SgoqqZtAkqJm0Rw6d5fBw==
Date:   Fri, 30 Nov 2018 11:47:40 +0000
Message-ID: <20181130114715.27523-4-dave.rodgman@arm.com>
References: <20181130114715.27523-1-dave.rodgman@arm.com>
In-Reply-To: <20181130114715.27523-1-dave.rodgman@arm.com>
Accept-Language: en-GB, en-US
Content-Language: en-US
x-ms-exchange-messagesentrepresentingtype: 1
x-ms-publictraffictype: Email
x-microsoft-exchange-diagnostics: 1;VI1PR0802MB2157;6:SIY3TovNSXiHliYsfcyhgdMBeGMV8JFdnXjEc1NF1/B2RXDLyf4lo3Dm0wxhHTIlVy+s1dmqdjSfBTwRT0E2iKDffW5qqKCtsbxRV+7cMrvIAR7gZwr5enNNcAmyITiiKYVD3ipHrE/Q4YuodezlnLzdwS3EbG0BxKR9Y9iLKw9ggboY+aMp+OSHH95c6Qe6jalV7f648uqms6vEeIIhkfzY9BLv4VRjulhZzjNnZu3IW18Yk7OXw69Ej+5pLFEdekMwbAIwg2shLBKe585ohtDy1Eo7eWk8MW6tTjKKahzzjPQ2/0N9KTWozoY09GNfMcQFNi8SevSqbzGj2ICQfJYL0DYdBKBNTNOuVC9o/OA1SmKcSfhL0xWqJ6IVw7gxTRo8v0/HXmc/h3UhktpYW20o4DqGT116AeKu/BOQsW/PnEhwyKuQt571gUJ5TILIjDQ0g1VnLFAv1B/taLqlkA==;5:ruDM/85J7U0L/2pUP7mhZJ6U/zuPhkP2cVzGwbntntQkcY5IpVudLV+9WU69r+9f/i0bCgIOFoqM66uFmzVonXxayIecSjMvx4t9kw0RU6bCny8y836yIOXgJlnF3wGGN2PfryhYgAkXK0JtBbjrHpgq8kGM7e/anbRRYlnAHqg=;7:jeJ8rUoYjQLd5CYKrxzw85gcbpXr4txckUp3g2n/0HIRy6tYuPCTr08kUoqQQMfHCmmvBNguYL9QuWboY9x9riOIzK9YVn2JkoW1VxwB1WXZagnKMnRt8kWINp3rFjo3S6QFtltu7aaKi12cB/gFFw==
x-ms-office365-filtering-correlation-id: 03d59cf0-79af-463d-258e-08d656b9a1f0
x-ms-office365-filtering-ht: Tenant
x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390098)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600074)(711020)(4618075)(2017052603328)(7153060)(7193020);SRVR:VI1PR0802MB2157;
x-ms-traffictypediagnostic: VI1PR0802MB2157:
nodisclaimer: True
x-microsoft-antispam-prvs: <VI1PR0802MB21573CA0BA711B74CE885A5F8FD30@VI1PR0802MB2157.eurprd08.prod.outlook.com>
x-ms-exchange-senderadcheck: 1
x-exchange-antispam-report-cfa-test: BCL:0;PCL:0;RULEID:(8211001083)(6040522)(2401047)(8121501046)(5005006)(3231453)(999002)(944501466)(4982022)(52105112)(10201501046)(93006095)(93001095)(3002001)(6055026)(148016)(149066)(150057)(6041310)(20161123558120)(20161123562045)(201703131423095)(201702281528075)(20161123555045)(201703061421075)(201703061406153)(20161123564045)(20161123560045)(201708071742011)(7699051)(76991095);SRVR:VI1PR0802MB2157;BCL:0;PCL:0;RULEID:;SRVR:VI1PR0802MB2157;
x-forefront-prvs: 087223B4DA
x-forefront-antispam-report: SFV:NSPM;SFS:(10009020)(39860400002)(366004)(396003)(346002)(136003)(376002)(199004)(189003)(50226002)(53936002)(26005)(6306002)(4326008)(186003)(305945005)(7736002)(97736004)(11346002)(54906003)(316002)(68736007)(6512007)(6436002)(14444005)(6486002)(386003)(6506007)(102836004)(81166006)(81156014)(256004)(76176011)(52116002)(8676002)(476003)(2616005)(71190400001)(446003)(71200400001)(486006)(575784001)(39060400002)(99286004)(86362001)(14454004)(44832011)(106356001)(966005)(478600001)(2906002)(25786009)(105586002)(66066001)(8936002)(7416002)(1076002)(110136005)(2501003)(5660300001)(36756003)(3846002)(6116002);DIR:OUT;SFP:1101;SCL:1;SRVR:VI1PR0802MB2157;H:VI1PR0802MB2528.eurprd08.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;A:1;MX:1;
received-spf: None (protection.outlook.com: arm.com does not designate
 permitted sender hosts)
x-microsoft-antispam-message-info: M+zzCyz2AOc0WfQOT8OuoxQZKA8u1DwywkUKEwFAg2kmfIuhR68Fm+t/9YbXbwo4f8f6hgPj0H2pE9LhPCvxg3v9MxlPlt2kU0n7XGzPPcajreR4ZiXy0H9abhWYko+7jJFOX2GyFpflAmLUy3vsvOXzB+s9nEGwSgT4cdqbr445YLgNdyV19Ey7Mz6w57Wz4UReNUXUC8gM2abhh63FssX4g4Zvdbtq5XCbQKgnWf2AQhKMTh+kYSZJDLt1yD4NLXbTFsdrGO0Ve/M/XXwSZr8ut4057kX2vxD08xJDZkbCOf0JnKaMB5YK8Nici7++r560lTZ02nXkC2dNZeJ+pVBNboq1ZBLQ1RZuxR7bmHM=
spamdiagnosticoutput: 1:99
spamdiagnosticmetadata: NSPM
Content-Type: text/plain; charset="iso-8859-1"
Content-Transfer-Encoding: quoted-printable
MIME-Version: 1.0
X-OriginatorOrg: arm.com
X-MS-Exchange-CrossTenant-Network-Message-Id: 03d59cf0-79af-463d-258e-08d656b9a1f0
X-MS-Exchange-CrossTenant-originalarrivaltime: 30 Nov 2018 11:47:40.8565
 (UTC)
X-MS-Exchange-CrossTenant-fromentityheader: Hosted
X-MS-Exchange-CrossTenant-id: f34e5979-57d9-4aaa-ad4d-b122a662184d
X-MS-Exchange-Transport-CrossTenantHeadersStamped: VI1PR0802MB2157
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk
List-ID: <linux-kernel.vger.kernel.org>
X-Mailing-List: linux-kernel@vger.kernel.org

From: Matt Sealey <matt.sealey@arm.com>

ARMv6 Thumb state introduced an RBIT instruction which, combined with CLZ
as present in ARMv5, introduces an extremely fast path for counting
trailing zeroes.

Enable the use of the GCC builtin for this on ARMv6+ with
CONFIG_THUMB2_KERNEL to ensure we get the 'new' instruction usage.

We do not bother enabling LZO_USE_CTZ64 support for ARMv5 as the builtin
code path does the same thing as the LZO_USE_CTZ32 code, only with more
register pressure.

Link: http://lkml.kernel.org/r/20181127161913.23863-4-dave.rodgman@arm.com
Signed-off-by: Matt Sealey <matt.sealey@arm.com>
Signed-off-by: Dave Rodgman <dave.rodgman@arm.com>
Cc: David S. Miller <davem@davemloft.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Markus F.X.J. Oberhumer <markus@oberhumer.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Nitin Gupta <nitingupta910@gmail.com>
Cc: Richard Purdie <rpurdie@openedhand.com>
Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com>
Cc: Sonny Rao <sonnyrao@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
---
 lib/lzo/lzodefs.h | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/lib/lzo/lzodefs.h b/lib/lzo/lzodefs.h
index e1b3cf6459a9..c0193f726db0 100644
--- a/lib/lzo/lzodefs.h
+++ b/lib/lzo/lzodefs.h
@@ -33,9 +33,14 @@
 #define LZO_USE_CTZ32	1
 #elif defined(CONFIG_X86) || defined(CONFIG_PPC)
 #define LZO_USE_CTZ32	1
-#elif defined(CONFIG_ARM) && (__LINUX_ARM_ARCH__ >=3D 5)
+#elif defined(CONFIG_ARM)
+#if (__LINUX_ARM_ARCH__ >=3D 5)
 #define LZO_USE_CTZ32	1
 #endif
+#if (__LINUX_ARM_ARCH__ >=3D 6) && defined(CONFIG_THUMB2_KERNEL)
+#define LZO_USE_CTZ64	1
+#endif
+#endif
=20
 #define M1_MAX_OFFSET	0x0400
 #define M2_MAX_OFFSET	0x0800
--=20
2.17.1