From nobody Mon Feb 9 12:01:43 2026 Received: from forward206b.mail.yandex.net (forward206b.mail.yandex.net [178.154.239.151]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3EF7422576E; Wed, 8 Oct 2025 12:53:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=178.154.239.151 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759927992; cv=none; b=h+bzvCEwohWXh5THwxm3Zg94Q0/pwDn1CJ0ysaqse0Ay2J3VPic+9yXPtiu02v03VOaakM4whGEj1fZQ6bk8Y4RCGEU9jmxpSkbf7vh5zf9Q9398tLfXPRB177anFc2UIfP5RQ569/taeFc5HjmyzExGEWQIkXeyOjHBgQf+duM= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759927992; c=relaxed/simple; bh=M4vQ/ICTS7HOdkm3Eyry1Ae2cRQyR4+iqQSeG7AUovY=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=kXACXgyF7MyocUs3xBl/U7r/YtxxBq+MVURazG2taapNylDHcp1Ydyn798/hSjUKoGct9yXyK+xVEs+ktZ5aFjcyOnUHOEFgFBbvflVnTB8L7WNVoSq4VPWWWHyjxD9l/UrYHEdvfM0Tj5TttfeujcjUwhhvy/1Rnrrs3zCKzmI= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=onurozkan.dev; spf=pass smtp.mailfrom=onurozkan.dev; dkim=pass (1024-bit key) header.d=onurozkan.dev header.i=@onurozkan.dev header.b=d94HbiTA; arc=none smtp.client-ip=178.154.239.151 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=onurozkan.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=onurozkan.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=onurozkan.dev header.i=@onurozkan.dev header.b="d94HbiTA" Received: from forward101b.mail.yandex.net (forward101b.mail.yandex.net [IPv6:2a02:6b8:c02:900:1:45:d181:d101]) by forward206b.mail.yandex.net (Yandex) with ESMTPS id 3EDE38371D; Wed, 08 Oct 2025 15:47:36 +0300 (MSK) Received: from mail-nwsmtp-smtp-production-main-74.sas.yp-c.yandex.net (mail-nwsmtp-smtp-production-main-74.sas.yp-c.yandex.net [IPv6:2a02:6b8:c1b:3715:0:640:1185:0]) by forward101b.mail.yandex.net (Yandex) with ESMTPS id 1F57CC008F; Wed, 08 Oct 2025 15:47:28 +0300 (MSK) Received: by mail-nwsmtp-smtp-production-main-74.sas.yp-c.yandex.net (smtp/Yandex) with ESMTPSA id LklD46OLveA0-F6jyaQdz; Wed, 08 Oct 2025 15:47:26 +0300 X-Yandex-Fwd: 1 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=onurozkan.dev; s=mail; t=1759927646; bh=9zjv8cFRBo9Unx3PUTFt2Dg057u0swwLrQZWxNbSWj4=; h=Cc:Message-ID:References:Date:In-Reply-To:Subject:To:From; b=d94HbiTA+/qglKjJNUP8UVu3bp8xKNT88f5lgUR+fkNWhAJlK+ztEZp8TWsToIzAw MhBlPnbG3663GBUWrs07fyw2dKY3CHazNA7NRMOHgF/ci1zgL6+7VvLLhPLp2R4uVI Iko7lWPUHDqcjZXLTjT99r3iXrE4YdTbi+G4E+kU= Authentication-Results: mail-nwsmtp-smtp-production-main-74.sas.yp-c.yandex.net; dkim=pass header.i=@onurozkan.dev From: =?UTF-8?q?Onur=20=C3=96zkan?= To: rust-for-linux@vger.kernel.org Cc: ojeda@kernel.org, alex.gaynor@gmail.com, boqun.feng@gmail.com, gary@garyguo.net, bjorn3_gh@protonmail.com, lossin@kernel.org, aliceryhl@google.com, tmgross@umich.edu, dakr@kernel.org, linux-kernel@vger.kernel.org, acourbot@nvidia.com, airlied@gmail.com, simona@ffwll.ch, maarten.lankhorst@linux.intel.com, mripard@kernel.org, tzimmermann@suse.de, corbet@lwn.net, lyude@redhat.com, linux-doc@vger.kernel.org, linux-mm@kvack.org, =?UTF-8?q?Onur=20=C3=96zkan?= Subject: [PATCH v2 2/4] rust: xarray: abstract `xa_alloc` Date: Wed, 8 Oct 2025 15:46:17 +0300 Message-ID: <20251008124619.3160-3-work@onurozkan.dev> X-Mailer: git-send-email 2.51.0 In-Reply-To: <20251008124619.3160-1-work@onurozkan.dev> References: <20251008124619.3160-1-work@onurozkan.dev> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Implements `alloc` function to `XArray` that wraps `xa_alloc` safely, which will be used to generate the auxiliary device IDs. Resolves a task from the nova/core task list under the "XArray bindings [XARR]" section in "Documentation/gpu/nova/core/todo.rst" file. Signed-off-by: Onur =C3=96zkan --- rust/kernel/xarray.rs | 41 ++++++++++++++++++++++++++++++++++++++++- 1 file changed, 40 insertions(+), 1 deletion(-) diff --git a/rust/kernel/xarray.rs b/rust/kernel/xarray.rs index 90e27cd5197e..0711ccf99fb4 100644 --- a/rust/kernel/xarray.rs +++ b/rust/kernel/xarray.rs @@ -10,7 +10,7 @@ ffi::c_void, types::{ForeignOwnable, NotThreadSafe, Opaque}, }; -use core::{iter, marker::PhantomData, pin::Pin, ptr::NonNull}; +use core::{iter, marker::PhantomData, ops::Range, pin::Pin, ptr::NonNull}; use pin_init::{pin_data, pin_init, pinned_drop, PinInit}; /// An array which efficiently maps sparse integer indices to owned object= s. @@ -268,6 +268,45 @@ pub fn store( Ok(unsafe { T::try_from_foreign(old) }) } } + + /// Allocates an empty slot within the given `limit` and stores `value= ` there. + /// + /// May drop the lock if needed to allocate memory, and then reacquire= it afterwards. + /// + /// On success, returns the allocated index. + /// + /// On failure, returns the element which was attempted to be stored. + pub fn alloc( + &mut self, + limit: Range, + value: T, + gfp: alloc::Flags, + ) -> Result> { + let new =3D value.into_foreign(); + let mut id: u32 =3D 0; + + let limit =3D bindings::xa_limit { + min: limit.start, + max: limit.end, + }; + + // SAFETY: + // - `self.xa.xa` is valid by the type invariant. + // - `new` came from `T::into_foreign`. + let ret =3D + unsafe { bindings::__xa_alloc(self.xa.xa.get(), &mut id, new, = limit, gfp.as_raw()) }; + + if ret < 0 { + // SAFETY: `__xa_alloc` doesn't take ownership on error. + let value =3D unsafe { T::from_foreign(new) }; + return Err(StoreError { + value, + error: Error::from_errno(ret), + }); + } + + Ok(id) + } } // SAFETY: `XArray` has no shared mutable state so it is `Send` iff `T`= is `Send`. -- 2.51.0