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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?bImoeL3qYGIAT3RGYoZK9rcisxxv+TLen68vsQLx/vegGuu48mZYnPKzS/pq?= =?us-ascii?Q?GoSubp3nT322Lohk/DogJT2a9OKdlaGng8gKOsr/B5bL8OAsnQ3zJo+tTM7q?= =?us-ascii?Q?n6Wt9YmpGL3V/EUrqfHlTgHL3beUGWH7oNGpEsT9zKetqrtDODTA3C8KGr8X?= =?us-ascii?Q?vT46kgJg/5WvOblNOhMTOfzcTGCA0rTTYynJaYgbbjOwJMC6lrKgYRKYAavj?= =?us-ascii?Q?/sgz7F+IVmhxmBs7g70nE/GjMVO1d44WrPfp8Dyj3cybhe8xRZv345MrtV07?= =?us-ascii?Q?xFro/vvpnshsYduxv6AmwVq4dPXpCySs+bpVESqZK+CPAl+/x+veTEZZGXfj?= =?us-ascii?Q?pMvlnvyQhQ9oZThlungIRs/MYQDTZURPF+lPLif7zQ3v/9mIFvR4IHBBCC6m?= =?us-ascii?Q?IAwN/cdEdIp2XQ3FbNrgNOwa7B4Eh3X2FOatWhPFGbjNonEyvpAhCmUAujR8?= =?us-ascii?Q?1gKQZ9dXrm9Oy+zq2CTydZvbwcmJPe0NJHUNu8YdIJGA7Ef1vjAACtgrWWjq?= =?us-ascii?Q?2xN0SxL1gyNBDwHbtzx0VIVg4dvPVFbb8D1y7POKJtgZYQK7SK1GyV3fJrIC?= =?us-ascii?Q?8TwR7xnRzZBzWs1ftTkJH8c2L5yQtU5FXiQ0LLmK++amIeav+NHZwhvf+wZT?= =?us-ascii?Q?IUxU/UYiL+FRIaOOHBuiB8NOyX7lIyhLZ4DMVsg2UpbGeIvTf6HrRHI0eSOO?= =?us-ascii?Q?7hgPxlDyJrpOWTYn1q5H0ysJfpMpwb8efVnzaM/my9ANoM0UBBuxjhlbSouX?= =?us-ascii?Q?TZXZ0Qa8vVJYB9oKeUgOlyIcFkJTJiUd55wchV9+ACrC+KvEcVKVpbX22YMq?= =?us-ascii?Q?RpATL9aQnGKian72VHef3Bx8vWSJR6rlR2FN7Z2TV5izD2YVx3+2x6u4Sh3L?= =?us-ascii?Q?OqCPA6jju0JgzUNdUL46gv1SJ+FlbJrTWpkRgMDOE07sRNOduVfzS9SVGzae?= =?us-ascii?Q?4Qt+odEKQvVGJL6SoCEFwGExPPJs9GAi3hPNVNiat6wrY0Tgg/zUEV1GDq07?= =?us-ascii?Q?afAS88zsfTZSa6UgrSy9bKQHQU07f4fkLdC3HfR9zLjHn+vCpWDqm6If2HSq?= =?us-ascii?Q?HqTvCO1TYet2UyXhFU6B496baqatj6dxahG7RXCMSApG7EQ6mNkQqQxlze63?= =?us-ascii?Q?LZONIz5oiuUt1Tbh/rAZxVgBwfQVyH36DD9lIbV3h+oV1h0J836sN7Z0sb4a?= =?us-ascii?Q?AdMeLC91hFULYhRsGOhzYtp3LhKdhm1E3VZfpKJCd1yW/l8S4wgKkaWoW7DM?= =?us-ascii?Q?coG+jeNbyT1rgK2Ibc6EkdH8xrEzvlDXwpltNCYl3uZPu/0g8Ltup9jBd74o?= =?us-ascii?Q?e8NHSngYfVlX8foVyWhKWKzljBbUMb8ozHI2eUqmWKKY2nCdMvqGcfJpkEC0?= =?us-ascii?Q?8oO3K0PgrOcLAS2jBUpCHyMIgS2HGTAUKiLj3O0oLdhHu/HySZqE/bnZXPSF?= =?us-ascii?Q?Ln1HQAxw4HRaZCrAaQn79VSU9N+ByIWDxaTw4Eu6ceLeC+BvHVaaMCJ3zsAr?= =?us-ascii?Q?3UBnV452Hsrn1jZoh12A4L1zPQSBIlFpBSiPQRrZJMT5VdITbsT9cut4YORz?= =?us-ascii?Q?a+f+//oHcQ9cSzVqFqYH/z2X/F+tCOkQOPOeAIBV?= X-OriginatorOrg: Nvidia.com X-MS-Exchange-CrossTenant-Network-Message-Id: caab5f9f-9e4a-40d0-2178-08dccdc5c9f9 X-MS-Exchange-CrossTenant-AuthSource: CH3PR12MB7763.namprd12.prod.outlook.com X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 05 Sep 2024 16:14:16.1780 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: 43083d15-7273-40c1-b7db-39efd9ccc17a X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: 2j/BnXJTOOykMdpjsGI5/JRwXJ6yp9QZgm3yVvCS4uOBa+pO//ESOI4nKrHObxPv X-MS-Exchange-Transport-CrossTenantHeadersStamped: MN2PR12MB4045 X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240905_091421_021761_FF5DC952 X-CRM114-Status: GOOD ( 16.56 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Tue, Aug 27, 2024 at 09:59:47AM -0700, Nicolin Chen wrote: > Driver can call the iommufd_viommu_find_device() to find a device pointer > using its per-viommu virtual ID. The returned device must be protected by > the pair of iommufd_viommu_lock/unlock_vdev_id() function. > > Put these three functions into a new viommu_api file, to build it with the > IOMMUFD_DRIVER config. > > Signed-off-by: Nicolin Chen > --- > drivers/iommu/iommufd/Makefile | 2 +- > drivers/iommu/iommufd/viommu_api.c | 39 ++++++++++++++++++++++++++++++ > include/linux/iommufd.h | 16 ++++++++++++ > 3 files changed, 56 insertions(+), 1 deletion(-) > create mode 100644 drivers/iommu/iommufd/viommu_api.c I still think this is better to just share the struct content with the driver, eventually we want to do this anyhow as the driver will want to use container_of() techniques to reach its private data. > +/* > + * Find a device attached to an VIOMMU object using a virtual device ID that was > + * set via an IOMMUFD_CMD_VIOMMU_SET_VDEV_ID. Callers of this function must call > + * iommufd_viommu_lock_vdev_id() prior and iommufd_viommu_unlock_vdev_id() after > + * > + * Return device or NULL. > + */ > +struct device *iommufd_viommu_find_device(struct iommufd_viommu *viommu, u64 id) > +{ > + struct iommufd_vdev_id *vdev_id; > + > + lockdep_assert_held(&viommu->vdev_ids_rwsem); > + > + xa_lock(&viommu->vdev_ids); > + vdev_id = xa_load(&viommu->vdev_ids, (unsigned long)id); > + xa_unlock(&viommu->vdev_ids); No need for this lock, xa_load is rcu safe against concurrent writer Jason