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x-ms-exchange-messagesentrepresentingtype: 1 x-originating-ip: [94.118.89.251] x-ms-publictraffictype: Email x-ms-office365-filtering-correlation-id: 31247056-33f9-45f6-9500-08d72ad5c7d8 x-microsoft-antispam: BCL:0;PCL:0;RULEID:(2390118)(7020095)(4652040)(8989299)(4534185)(4627221)(201703031133081)(201702281549075)(8990200)(5600166)(711020)(4605104)(1401327)(2017052603328)(7193020);SRVR:MWHPR2201MB1390; x-ms-traffictypediagnostic: MWHPR2201MB1390: x-microsoft-antispam-prvs: x-ms-oob-tlc-oobclassifiers: OLM:4714; x-forefront-prvs: 0142F22657 x-forefront-antispam-report: SFV:NSPM;SFS:(10019020)(7916004)(366004)(39850400004)(376002)(136003)(396003)(346002)(189003)(199004)(71200400001)(486006)(102836004)(186003)(476003)(386003)(26005)(8676002)(42882007)(478600001)(6246003)(2906002)(305945005)(5660300002)(66066001)(53936002)(8936002)(9686003)(1076003)(446003)(14444005)(81156014)(6486002)(7736002)(81166006)(256004)(11346002)(4326008)(25786009)(14454004)(44832011)(52116002)(6512007)(58126008)(7416002)(6916009)(54906003)(76176011)(6116002)(3846002)(66946007)(66446008)(66476007)(66556008)(64756008)(33716001)(99286004)(71190400001)(316002)(6436002)(6506007)(229853002);DIR:OUT;SFP:1102;SCL:1;SRVR:MWHPR2201MB1390;H:MWHPR2201MB1277.namprd22.prod.outlook.com;FPR:;SPF:None;LANG:en;PTR:InfoNoRecords;MX:1;A:1; received-spf: None (protection.outlook.com: wavecomp.com does not designate permitted sender hosts) x-ms-exchange-senderadcheck: 1 x-microsoft-antispam-message-info: hzQ2W7D89/5bOMckqiyD4YmPVgAE+qzEqiVqLEhKTz76XIkalHuEwK5B8RO5FDj5VB80v63tntNByUn6Gd/gOgE6cflzAHG5dXBGD8KgsefRz4nUM/EpQXaDmwaDPu0C1wyF7go+Of4hHuwWIs/GaL+nAdaSD+6Cyh8RSd0oDis+apASwR/lr4gsW/NLoBazYjWbuTH87jVp2jp9QlubW9l7NhHMlwkCSbSjC6ibeiesKnqE5yraqZJpy10BSvnZSmnoYTcCiDFqC/w0wAfz+BDCyPNg6AAKq1VvXtm2EICLMVEhh6yeQScHpabuwGBWVyBeRZO6osHQ3nIR7aSCf5uK9TZ7FvSEPQWf50v9ukrBTDgDe7X4niP0uuM8dFbU9kGn7tHL9IJrN7gwiptGR50dwqDQkAGz8XRtS0UMtEI= x-ms-exchange-transport-forked: True Content-Type: text/plain; charset="us-ascii" Content-ID: <112563C691B9D24084999634B2E39C47@namprd22.prod.outlook.com> Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 X-OriginatorOrg: mips.com X-MS-Exchange-CrossTenant-Network-Message-Id: 31247056-33f9-45f6-9500-08d72ad5c7d8 X-MS-Exchange-CrossTenant-originalarrivaltime: 27 Aug 2019 10:03:16.7814 (UTC) X-MS-Exchange-CrossTenant-fromentityheader: Hosted X-MS-Exchange-CrossTenant-id: 463607d3-1db3-40a0-8a29-970c56230104 X-MS-Exchange-CrossTenant-mailboxtype: HOSTED X-MS-Exchange-CrossTenant-userprincipalname: ijY4BT1J6qbZ0asLVx9KlfJdlwGDY7JNLjL4/utrumR/7V7gpeHBxew9QwsJA+Izplvd0C8tBPzS1I/l2EOppg== X-MS-Exchange-Transport-CrossTenantHeadersStamped: MWHPR2201MB1390 Sender: linux-mips-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-mips@vger.kernel.org Hi Christoph, On Mon, Aug 26, 2019 at 03:25:53PM +0200, Christoph Hellwig wrote: > Based on an email from Paul Burton, quoting section 4.8 "Cacheability and > Coherency Attributes and Access Types" of "MIPS Architecture Volume 1: > Introduction to the MIPS32 Architecture" (MD00080, revision 6.01). >=20 > Signed-off-by: Christoph Hellwig Acked-by: Paul Burton Thanks, Paul > --- > arch/mips/Kconfig | 7 +++++++ > 1 file changed, 7 insertions(+) >=20 > diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig > index fc88f68ea1ee..aff1cadeea43 100644 > --- a/arch/mips/Kconfig > +++ b/arch/mips/Kconfig > @@ -1119,6 +1119,13 @@ config DMA_PERDEV_COHERENT > =20 > config DMA_NONCOHERENT > bool > + # > + # MIPS allows mixing "slightly different" Cacheability and Coherency > + # Attribute bits. It is believed that the uncached access through > + # KSEG1 and the implementation specific "uncached accelerated" used > + # by pgprot_writcombine can be mixed, and the latter sometimes provides > + # significant advantages. > + # > select ARCH_HAS_DMA_WRITE_COMBINE > select ARCH_HAS_SYNC_DMA_FOR_DEVICE > select ARCH_HAS_UNCACHED_SEGMENT > --=20 > 2.20.1 >=20