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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?VQRxIO017CunCg0dnLRNApcTP3O+OuNuMMy7QVFmiXqJuqSW7ohhdXboVygX?= =?us-ascii?Q?JtoBG0iUgR+V54D6MaQzXbL8AkbK9a8TiHsK2eBy1AKBJW5p5+gAwTRjAB1v?= =?us-ascii?Q?xEIqnKO94axznIrJrFEjX7zGNwqDieigIiWC1cthl+3JFnsfzlmpOZ9eFSwQ?= =?us-ascii?Q?LUrL3zW/M0rg5bSepOeMzUC8P3JRbRjhNwO8R9EBeWIvYGNUTJpwV4n/jI5b?= =?us-ascii?Q?B4NfJeSG2226Py2HoRRDTGYK/Z+W+Xs93AA5Oi22mgzh0n0daQuO/zMyrwXU?= =?us-ascii?Q?OJ3USlqf5unppvmsN1mQRkKJ067Xiug1O78XGoFXl1VVcQrGwNtQaLC82N+x?= =?us-ascii?Q?2nKNQYzxxV3faW6a8nfIm8foEm743lEWZcTa8QOVnUOX+rVziC0xA4yYQJ8y?= =?us-ascii?Q?4BsDww0FVXDbz0G1jlu/+62S1R0i9v+058I+9Y1EibwIKlzHvCDCwsXJ0yae?= =?us-ascii?Q?ddtA+XGrI2JUTCLRmX++khLoSv7yQbSvhm7bZy+AVZw5lKcLJRPENPW7suFg?= =?us-ascii?Q?adAieUhk6XsBFodJ0WIqs0oaNRM1XZH6VYQqdEzvtup1RI6Wea4tE2nZ2TjJ?= =?us-ascii?Q?IYrhYr41DHpXsRj59N8kFroT5WHTrs4DUkGS7jWOoB2rMgL8qWBIYwWuFUPH?= =?us-ascii?Q?kDElEJRm2ChQnRwTzGP361Hj7SwGl+U3LSIAO6FljZnajWudV6a9nmNNKBBH?= =?us-ascii?Q?Oy2XN/lQB+WWMvci2eDz0L7OksHTbxSs8lIU1O7Z4PPoyT4kesTiXDNNgl4o?= =?us-ascii?Q?Q/F/Z1y/RSUtBNGt22A7BuErRyfv+tSWobQYUelHzEjwrSlK3jPaWasSkrOn?= =?us-ascii?Q?1yY1k8GqA1ZLcmeMVmnPEhw8Zn5L1FZLo0ylGAa5CtedYLT0xPdTZJjFp0/6?= =?us-ascii?Q?Xws0gujB7W2wBHVhUz/GSEIcYGrzbhbbQ6IOrwVBUecDrQnVk/n5n4pAjw/D?= =?us-ascii?Q?KSFQxNEF3k1xNXT9XHyRCXgUrLUvOOTDpJb7+UzCp6vdpYIYNs/5YPzjXE9I?= =?us-ascii?Q?jhpvsAfMycWe0FCSQ7WN8XcyAbMlA9dIqHhR+c0Dt48En27kQTBY8ZndRqxR?= =?us-ascii?Q?wns9aLzUyNYezeVKa3zXc5x1jrmFAq76IRbmtqMpEf1T21aupMqi8AG0aTLU?= =?us-ascii?Q?6PijlPDVzGM961mrhZCoITlOemAJtDEdkqR7Kdb/aRxTb4CY1eyRDSbG74ik?= =?us-ascii?Q?AN8SrzODDyH00ZMl9MPOiECJwaJhFdAQbgeEZT0c2GqOHhBgJfevm3yMzC/+?= =?us-ascii?Q?kqXeFK1TOmZu9h8NeOsdQR3ovq0RNqoJ6TqQoZ6ZKo46JKNMME5IQbB7SWJT?= =?us-ascii?Q?AsQ9ADnyotuX7oZDbus/lKuWVZbQgkKXi4nWYwqpoUhzr1GsTyyAE8U2llpH?= =?us-ascii?Q?O7vQOlD+y/d7R6NZtp1zV7m2OcC/q9Oe3S18szOs7gK4iz+/cCvxpfPOko5v?= =?us-ascii?Q?2TDcsVU4J4P71Nnz3bgPnNgMmIusyat6qFan43+8w2BIoVa3zwbV1W2Rybwi?= =?us-ascii?Q?yr8a5EUW/6yVYhKw1ggPfh3IPsFBFJ3WPhPnvI48cJ3vvX+EPhbu2bhB20fh?= =?us-ascii?Q?ho9G3F/lnFua0Z6wpEvXRO4fqrUOVuVuhzfijPSYXV80JRzk/I33N+uI3a7k?= =?us-ascii?Q?PEb7khR75s0C4c+LFKw7eCAR+XRSCu52/Ps6Rc/4zjhJYqnXg03OXHk4fyd7?= =?us-ascii?Q?Cxu97A=3D=3D?= X-OriginatorOrg: corigine.com X-MS-Exchange-CrossTenant-Network-Message-Id: 4bea9f9b-e763-43b9-3687-08db3f42c2b8 X-MS-Exchange-CrossTenant-AuthSource: PH0PR13MB4842.namprd13.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 17 Apr 2023 12:53:37.1646 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: fe128f2c-073b-4c20-818e-7246a585940c X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: V8TOmf2utuXlxeHemq7Y1PbPw7zNUNTcFuJjKzSxOW5aqN3O0uNzH3o454FGi7R7Vv54nr9hk8jpLbsaUmBHV/ZteC3xuO7hGTjHUSv5Pp0= X-MS-Exchange-Transport-CrossTenantHeadersStamped: MW3PR13MB3996 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Sat, Apr 15, 2023 at 08:05:46PM +0300, Vladimir Oltean wrote: > Unfortunately, the workarounds for the hardware bugs make it pointless > to keep fine-grained locking for the MAC Merge state of each port. > > Our vsc9959_cut_through_fwd() implementation requires > ocelot->fwd_domain_lock to be held, in order to serialize with changes > to the bridging domains and to port speed changes (which affect which > ports can be cut-through). Simultaneously, the traffic classes which can > be cut-through cannot be preemptible at the same time, and this will > depend on the MAC Merge layer state (which changes from threaded > interrupt context). > > Since vsc9959_cut_through_fwd() would have to hold the mm->lock of all > ports for a correct and race-free implementation with respect to > ocelot_mm_irq(), in practice it means that any time a port's mm->lock is > held, it would potentially block holders of ocelot->fwd_domain_lock. > > In the interest of simple locking rules, make all MAC Merge layer state > changes (and preemptible traffic class changes) be serialized by the > ocelot->fwd_domain_lock. > > Signed-off-by: Vladimir Oltean Reviewed-by: Simon Horman