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X-MS-Exchange-AntiSpam-MessageData-ChunkCount: 1 X-MS-Exchange-AntiSpam-MessageData-0: =?us-ascii?Q?9JKamoJ+HO+tTE2tx93SlNBXHNEfCO3PpsjgO0LzQ7VsX3IPwwbh4A2qEL03?= =?us-ascii?Q?f5ohC0Zz4mbhc7CHnrPufgkzM5FNRjPBAUjEpFnmgoXJWqzkOp2CYlSwaltt?= =?us-ascii?Q?9bBVf+eH/1nA04dzUN7YL1SYxqpw1JZhdgyHgQ7QHv2EUTNaiRtxeW8RNn+J?= =?us-ascii?Q?witz45HyfyBkrQGRtVwurqBczi7iFh8fOsqRp6vDKb79onVEYD/b3Tzs2cxn?= =?us-ascii?Q?2wuuoVPdvZW89cVTa+4T/M6I3xurCwBVcJl6ZEg1mbNgKk0wD5EXYZ02OeQR?= =?us-ascii?Q?YwVDnhOBTSQjnl30IRymoS0pYr8Fw1Lleiw/nb44oyFLQ7P0PaIEbHudjXn9?= =?us-ascii?Q?Lv+2ZIbCYYheaqZQhFER8eRh9lskvfb9qpLrx+o6+IaKuF2PJvILrrTxvHMf?= =?us-ascii?Q?SOCL6ImYyZf5dgdNIhXwkiv/u5RCts2PqONNKg8ulqjm1TeOJ9VyVnJZb9/l?= =?us-ascii?Q?zNcPhW/Sz0WHSz2iRQF1Ju5z7Vre7AfaUPxo6oQVdwycHV1z0T1GxU7HSpzF?= =?us-ascii?Q?kfMmaNvxEmEZsq6BFCVV+cDZgGwNTTLZ73AjtRPLaINqPFfrVHo1YP4DBb/e?= =?us-ascii?Q?Lzh2S/+p/XCcF6bUNtLStiaH6pTBpBo2sxIRVYNzdmb9NCiUjiMOcYl2jxEk?= =?us-ascii?Q?tVDU9LMVkI19kNpObn0MxK6EP5xMOA62VSsHt5FUpcG60+dW2C6B9j0TdTEz?= =?us-ascii?Q?TkMbbCV8vgMdYyaZSTSW1eOolSXUBN28Upucl4czHhEWIdxiEcp0N0DJocRv?= =?us-ascii?Q?KoCRlbwL50VRWESynSSmQaR96lDYxjVrxSNZ/1iMiJcl9xLH9b6ciZ/TSwTn?= =?us-ascii?Q?fTaZHCPrFpeusQo32l2Ov337bKUe2wcbTuP5IpF96cQj4Ox/cBOnX/uoGWPL?= =?us-ascii?Q?VGkDdN0Lwv3yyhn0MMqA2YrAmk4jM+qZxGh7NW41/loMFnOMFqCAb09hlDXL?= =?us-ascii?Q?hxsBErKgvFNTsUqjM7KY24J6fhEsGjA+PgHdnvbuESyoivbGAIjtq65+FhV2?= =?us-ascii?Q?SQSSSZr0RXRyNsqLrnnp4cjxUv1sb9r9ru8ipD3D+Gecp7xs7VtrNR02+mQ6?= =?us-ascii?Q?mAkrIz50nZ76sZZFyo9a0ffw0ILL66r1AoG0F9QVf10lk77EKOflt+TN1O3O?= =?us-ascii?Q?QqzYjqV3r4WfKYwm54bwPl0YC7ivPhCdQZlkHu/0KSOkZybwRP3UFlCu9bGW?= =?us-ascii?Q?os98NAo+4BxqhRw7alAJ6TyhFYTotx8QKRfz0XITqefBKKuoCLKCCGiHCkt6?= =?us-ascii?Q?ttZavOBc2ECHmtPrp/VThwYudenD5TdCswBMT/EvdVn/L6BKEM1hECfScEO3?= =?us-ascii?Q?UewDeWSm6oWQQ69ajX1RJlDoODEvd6NyZsd3rPl0+n8ovg/QXhnTzLd/xia5?= =?us-ascii?Q?24/3XeE1dMQQLUxLQk4iCjy2Y35zMD2PZufDKPQveC4JbeVGtVuT7QAIgGDq?= =?us-ascii?Q?ZKMZwsJ7u8WLYy38ldD8K69Qt9hIOeq2Q0BqNkjNpabjBvLpNCRPptgAu3fe?= =?us-ascii?Q?0mfXASBMW5u7VtuYIqX/NRoNcDPY1D38Bi784N/w6F+WMgudrAsU2bsg2+in?= =?us-ascii?Q?R6Xg5t3RltV7yHAosE7xVFxx83N44UlYHZRlE5Vm?= X-OriginatorOrg: garyguo.net X-MS-Exchange-CrossTenant-Network-Message-Id: 17983992-3a9e-44a9-0a16-08db0528f8fa X-MS-Exchange-CrossTenant-AuthSource: LO2P265MB5183.GBRP265.PROD.OUTLOOK.COM X-MS-Exchange-CrossTenant-AuthAs: Internal X-MS-Exchange-CrossTenant-OriginalArrivalTime: 02 Feb 2023 14:22:53.8117 (UTC) X-MS-Exchange-CrossTenant-FromEntityHeader: Hosted X-MS-Exchange-CrossTenant-Id: bbc898ad-b10f-4e10-8552-d9377b823d45 X-MS-Exchange-CrossTenant-MailboxType: HOSTED X-MS-Exchange-CrossTenant-UserPrincipalName: u4bRSFQb9Ao8EjOYYMnfdGjmjugqlF6647K83ZCvo4p6NtRmYEncNTHf986PjGK3mpPi8nxfAcWAAPoiglWLXQ== X-MS-Exchange-Transport-CrossTenantHeadersStamped: LO0P265MB6146 Precedence: bulk List-ID: X-Mailing-List: rust-for-linux@vger.kernel.org On Wed, 1 Feb 2023 15:22:41 -0800 Boqun Feng wrote: > This allows reading the current count of a refcount in an `ArcInner`. > > Signed-off-by: Boqun Feng Reviewed-by: Gary Guo > --- > rust/helpers.c | 6 ++++++ > rust/kernel/sync/arc.rs | 9 +++++++++ > 2 files changed, 15 insertions(+) > > diff --git a/rust/helpers.c b/rust/helpers.c > index 09a4d93f9d62..afc5f1a39fef 100644 > --- a/rust/helpers.c > +++ b/rust/helpers.c > @@ -46,6 +46,12 @@ bool rust_helper_refcount_dec_and_test(refcount_t *r) > } > EXPORT_SYMBOL_GPL(rust_helper_refcount_dec_and_test); > > +unsigned int rust_helper_refcount_read(refcount_t *r) > +{ > + return refcount_read(r); > +} > +EXPORT_SYMBOL_GPL(rust_helper_refcount_read); > + > /* > * We use `bindgen`'s `--size_t-is-usize` option to bind the C `size_t` type > * as the Rust `usize` type, so we can use it in contexts where Rust > diff --git a/rust/kernel/sync/arc.rs b/rust/kernel/sync/arc.rs > index fc680a4a795c..fbfceaa3096e 100644 > --- a/rust/kernel/sync/arc.rs > +++ b/rust/kernel/sync/arc.rs > @@ -127,6 +127,15 @@ struct ArcInner { > data: T, > } > > +impl ArcInner { > + /// Returns the current reference count of [`ArcInner`]. > + fn count(&self) -> u32 { > + // SAFETY: `self.refcount.get()` is always a valid pointer, and `refcount_read()` is a > + // normal atomic read (i.e. no data race) only requiring on the address is valid. > + unsafe { bindings::refcount_read(self.refcount.get()) } > + } > +} > + > // This is to allow [`Arc`] (and variants) to be used as the type of `self`. > impl core::ops::Receiver for Arc {} >