From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wr1-f74.google.com (mail-wr1-f74.google.com [209.85.221.74]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 39E1A36604C for ; Tue, 5 May 2026 13:29:55 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.221.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777987799; cv=none; b=fsUHdnlCKKWTOhTI5GQvCoC0CrvgrZOPQM5ZXtrTTYFoyjcaCQ06W4fXYTTucAWBs4RTrwCbBV7347WjfocG+//gA3/HtyQAo7npqLl4u6UGlLJdUqlnr9gOXFWDqWz7CNVSdX0+RLp7AK1JcNVcmBT53u3oh2++Y0matZasa60= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777987799; c=relaxed/simple; bh=D38IP4eDNtMMI0IcGktFlp2eQ3DhTGlCsra4pFAIzVw=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=pK5xtzlpNIW6OEjU2MZR9VlBX5aytlaSzM6mR+H9t5soUWMKqtm7FwS2zLjrE17JD503p2LbdFexNs7VzXYbCMWjCPlPEhnpPsj/aS3UStC9XpsjzN2Yja81WTFyvwicSa0KjkKvOWaZF5QSSUnNZbVeszl0Sr/pKNtWm2gH2TM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b=mDEiVabX; arc=none smtp.client-ip=209.85.221.74 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=google.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=flex--aliceryhl.bounces.google.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=google.com header.i=@google.com header.b="mDEiVabX" Received: by mail-wr1-f74.google.com with SMTP id ffacd0b85a97d-44a71109b94so3289647f8f.3 for ; Tue, 05 May 2026 06:29:55 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20251104; t=1777987794; x=1778592594; darn=vger.kernel.org; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:from:to:cc:subject:date:message-id:reply-to; bh=h2RGX6Vwv6i9Ia+V/bXwK0J5Boae0O+Cfqmb25x4+UY=; b=mDEiVabXt9owy/Xi7AcDk89uOSF0/YD9+v9mziwyj+B1RaycEe5gY4jkQB60u+TNq/ //dn6YuWSssbwRBeBxRL5R39l53/sgu3FZ5C2BY4NIEqGBEJ2p6U1Oi4XeQQJVAYfhSM gCpKPLooWKScQBx8sTpt7KtmHZc2+ZXgnkR9zW1oHqLWf8BBDTM6hxLd2ODtSfCPmni5 LkYBTbqloh19GNRDTRN5sQ25qc/zDTqB3Cf0lbLq7c3edRvyBZ1Dytpvz/7ebOpVKEfF fm6HKry/Y85E/DbciTT9eqDAy2hsJwfaWrtsL+qwmo8eSU9ZK1RpmMa03zVq1rsKq641 zfIQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1777987794; x=1778592594; h=cc:to:from:subject:message-id:references:mime-version:in-reply-to :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=h2RGX6Vwv6i9Ia+V/bXwK0J5Boae0O+Cfqmb25x4+UY=; b=pt7gUVoo1P88667ixtdUJI4/+ZoBepIsNmFAp/p/U/Y0xlKmwYBK7hG0sv5hbTA110 HBS1hVaafvE1GmZGeBj/Q0tdYk+PcgURBESmJ7psO8foJDophxnPLLudAsXXdBnBxS/m mlzqVjP4ZvEIh88GrpGK3rdiFTjWo3pChVdMEvh5wOdESotdeT/NJuCn/YRdKRevZs6s va0iF2NwUXSMZiVDKMguH3wX+xUn30IPfSWRai+R8xsqcZTmrqcShdgNhPrlXuvnZ1+9 waO5EebTCd3vhVtcc6813z4m+5LRed6xzPFJt6/wnSHpvhbOpOX3aksyS7nrXQc/efZs XrFw== X-Forwarded-Encrypted: i=1; AFNElJ+JveDSWRmOMs5XP6tvNRwLGv72Y/S0BYHdIgzpTFezmDaSsKap74lDxBGUT33kYpegBxkyS+aMrlcaWNI=@vger.kernel.org X-Gm-Message-State: AOJu0YxZ0Xp2zSczbArNZ+0Oyl8VEqMOgT+Fo4o0LzM+GQUuuRbPtiO3 htV//PWIwI35GQfcdlaGIBmRGdKx5oraABSmbjuKlte0sDW1kYLv87itLkYgV6EhDe4S4xA+Ule 0MsJ8KXkgj38CB/EPMQ== X-Received: from wrbes25.prod.google.com ([2002:a05:6000:44d9:b0:44a:70d3:31fd]) (user=aliceryhl job=prod-delivery.src-stubby-dispatcher) by 2002:a5d:444c:0:b0:44b:d58b:6a01 with SMTP id ffacd0b85a97d-44bd59aada4mr15775676f8f.1.1777987793893; Tue, 05 May 2026 06:29:53 -0700 (PDT) Date: Tue, 05 May 2026 13:29:37 +0000 In-Reply-To: <20260505-gpuvm-drm-exec-v1-0-958306ded36e@google.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <20260505-gpuvm-drm-exec-v1-0-958306ded36e@google.com> X-Developer-Key: i=aliceryhl@google.com; a=openpgp; fpr=49F6C1FAA74960F43A5B86A1EE7A392FDE96209F X-Developer-Signature: v=1; a=openpgp-sha256; l=6284; i=aliceryhl@google.com; h=from:subject:message-id; bh=D38IP4eDNtMMI0IcGktFlp2eQ3DhTGlCsra4pFAIzVw=; b=owEBbQKS/ZANAwAKAQRYvu5YxjlGAcsmYgBp+fDNU9ynbvS3XqymbWEIFFSYVxq4nVooOCqAz 8ojvGQzQrSJAjMEAAEKAB0WIQSDkqKUTWQHCvFIvbIEWL7uWMY5RgUCafnwzQAKCRAEWL7uWMY5 RhxWEACUfl0Spaz0xAbL0EstZcKnvjGq70NJR0uHyy/8h4gZQYldwrE+tFVx9pa6WzyND2y5gbL +29uPSTOfRxUfwtkr/WVnPlBvxGxJWZ6YWd6VV8cLqmy7hZwUSI3SyD6zTVsTKfC8J64OkcoTCK aQRz7zUqG0aFmaL55YE0pZB4L5pAeyM64FL6NTLJ9KK5kWt9MVfmJARTrjNYuo4x0cGHWQG76c/ ftxOTAjFr1EFv/+dQYO7Jau+YFAgywBT+AO+aaWQcOOE2YOphCykKAxv2X7Ll0bR+D1JijF9Snb mn2RCFCU2VAA4v2Rr6c7DoRxY1bEaZl4ovdMo0dEvKqT1xOK8i5qIMmpUXN1TyS7/tRMixWlxyR b+EzeVH/TjKWDo8i3W6kcXXm2wRG6or/q1YFNQLgowdcy0nFuQDTYr52FAw5NoWftLY/mNIjVSI jeVI2lsO3Xm1YCIERvFheCpBFOiwx6mtsNMH2LmSdeI4DalQDf0eaoW1ACHsI1g7NqjBmyxXTjl X2mt6gmE8/Z/JAF/itemiWpj4TRo/tF9FoxhGh0KYmPpTzlJVprRCl+4EEazKwbHwuUxLnEg8RN AKgpGFxsO+YpgrytwrriLKkSPAMmFoobSQNe6P7fNu1v0W7hgNvwe0VMgTMXC8zd8Cloj/GtzeC STnjuONyxsqk9QQ== X-Mailer: b4 0.14.3 Message-ID: <20260505-gpuvm-drm-exec-v1-2-958306ded36e@google.com> Subject: [PATCH 2/2] drm/gpuvm: rust: add drm_gpuvm_exec support From: Alice Ryhl To: Danilo Krummrich , Matthew Brost , "=?utf-8?q?Thomas_Hellstr=C3=B6m?=" , Daniel Almeida , Boris Brezillon , Gary Guo , "=?utf-8?q?Onur_=C3=96zkan?=" , Philipp Stanner Cc: Sumit Semwal , "=?utf-8?q?Christian_K=C3=B6nig?=" , Miguel Ojeda , Boqun Feng , "=?utf-8?q?Bj=C3=B6rn_Roy_Baron?=" , Benno Lossin , Andreas Hindborg , Trevor Gross , linux-kernel@vger.kernel.org, rust-for-linux@vger.kernel.org, dri-devel@lists.freedesktop.org, Alice Ryhl Content-Type: text/plain; charset="utf-8" This adds support for simple usage of drm_gpuvm_exec() for locking all of the dma reservations and adding fences to them. For more complex usage that does not involve locking all reservations, it is expected that the ww-mutex abstractions will be used instead. Signed-off-by: Alice Ryhl --- rust/bindings/bindings_helper.h | 2 ++ rust/helpers/drm_gpuvm.c | 6 ++++ rust/kernel/dma_buf/mod.rs | 17 ++++++++++ rust/kernel/drm/gpuvm/mod.rs | 71 +++++++++++++++++++++++++++++++++++++++++ 4 files changed, 96 insertions(+) diff --git a/rust/bindings/bindings_helper.h b/rust/bindings/bindings_helper.h index 1124785e210b..3978682a6f2e 100644 --- a/rust/bindings/bindings_helper.h +++ b/rust/bindings/bindings_helper.h @@ -151,6 +151,8 @@ const vm_flags_t RUST_CONST_HELPER_VM_MIXEDMAP = VM_MIXEDMAP; const vm_flags_t RUST_CONST_HELPER_VM_HUGEPAGE = VM_HUGEPAGE; const vm_flags_t RUST_CONST_HELPER_VM_NOHUGEPAGE = VM_NOHUGEPAGE; +const u32 RUST_CONST_HELPER_DRM_EXEC_INTERRUPTIBLE_WAIT = DRM_EXEC_INTERRUPTIBLE_WAIT; + #if IS_ENABLED(CONFIG_GPU_BUDDY) const unsigned long RUST_CONST_HELPER_GPU_BUDDY_RANGE_ALLOCATION = GPU_BUDDY_RANGE_ALLOCATION; const unsigned long RUST_CONST_HELPER_GPU_BUDDY_TOPDOWN_ALLOCATION = GPU_BUDDY_TOPDOWN_ALLOCATION; diff --git a/rust/helpers/drm_gpuvm.c b/rust/helpers/drm_gpuvm.c index 4130b6325213..30fb1777fbf2 100644 --- a/rust/helpers/drm_gpuvm.c +++ b/rust/helpers/drm_gpuvm.c @@ -23,4 +23,10 @@ bool rust_helper_drm_gpuvm_is_extobj(struct drm_gpuvm *gpuvm, return drm_gpuvm_is_extobj(gpuvm, obj); } +__rust_helper +void rust_helper_drm_gpuvm_exec_unlock(struct drm_gpuvm_exec *vm_exec) +{ + drm_gpuvm_exec_unlock(vm_exec); +} + #endif // CONFIG_RUST_DRM_GPUVM diff --git a/rust/kernel/dma_buf/mod.rs b/rust/kernel/dma_buf/mod.rs index b66e747c35ad..234936ba8265 100644 --- a/rust/kernel/dma_buf/mod.rs +++ b/rust/kernel/dma_buf/mod.rs @@ -5,3 +5,20 @@ pub mod dma_fence; pub use self::dma_fence::Fence; + +/// How the fences from a `dma_resv` obj are used. +/// +/// Please see [the C-side documentation][dma_resv_usage] for more details. +/// +/// [dma_resv_usage]: https://docs.kernel.org/driver-api/dma-buf.html#c.dma_resv_usage +#[repr(u32)] +pub enum DmaResvUsage { + /// For in kernel memory management only (e.g. copying, clearing memory). + Kernel = bindings::dma_resv_usage_DMA_RESV_USAGE_KERNEL, + /// Implicit write synchronization for userspace submissions. + Write = bindings::dma_resv_usage_DMA_RESV_USAGE_WRITE, + /// Implicit read synchronization for userspace submissions. + Read = bindings::dma_resv_usage_DMA_RESV_USAGE_READ, + /// No implicit sync (e.g. preemption fences, page table updates, TLB flushes). + Bookkeep = bindings::dma_resv_usage_DMA_RESV_USAGE_BOOKKEEP, +} diff --git a/rust/kernel/drm/gpuvm/mod.rs b/rust/kernel/drm/gpuvm/mod.rs index ae58f6f667c1..a52fb25f22ff 100644 --- a/rust/kernel/drm/gpuvm/mod.rs +++ b/rust/kernel/drm/gpuvm/mod.rs @@ -16,6 +16,7 @@ Flags as AllocFlags, // }, bindings, + dma_buf::{DmaResvUsage, Fence}, drm, drm::gem::IntoGEMObject, error::to_result, @@ -216,6 +217,30 @@ pub fn obtain( Ok(GpuVmBoAlloc::new(self, obj, data)?.obtain()) } + /// Prepare this GPUVM. + /// + /// The parameter indicates how many fences to preallocate space for. + #[inline] + pub fn prepare(&self, num_fences: u32) -> impl PinInit, Error> { + try_pin_init!(GpuVmExec { + exec <- Opaque::try_ffi_init(|exec: *mut bindings::drm_gpuvm_exec| { + // SAFETY: exec is valid but unused memory, so we can write. + unsafe { + ptr::write_bytes(exec, 0u8, 1usize); + ptr::write(&raw mut (*exec).vm, self.as_raw()); + ptr::write(&raw mut (*exec).flags, bindings::DRM_EXEC_INTERRUPTIBLE_WAIT); + ptr::write(&raw mut (*exec).num_fences, num_fences); + } + + // SAFETY: If successful, this `struct drm_gpuvm_exec` remains valid until this is + // unlocked because it's pinned and unlocks it in drop. The contained pointer to + // `self` remains valid because `GpuVmExec` borrows from `self`. + to_result(unsafe { bindings::drm_gpuvm_exec_lock(exec) }) + }), + _gpuvm: PhantomData, + }) + } + /// Clean up buffer objects that are no longer used. #[inline] pub fn deferred_cleanup(&self) { @@ -326,3 +351,49 @@ fn deref(&self) -> &GpuVm { &self.0 } } + +/// The exec token for preparing the objects. +/// +/// # Invariants +/// +/// Owns a GPUVM exec context. +#[pin_data(PinnedDrop)] +pub struct GpuVmExec<'vm, T: DriverGpuVm> { + #[pin] + exec: Opaque, + _gpuvm: PhantomData<&'vm mut GpuVm>, +} + +impl<'vm, T: DriverGpuVm> GpuVmExec<'vm, T> { + /// Add a fence. + /// + /// The caller must ensure that the preallocated space for fences is sufficient. + #[inline] + pub fn resv_add_fence( + &self, + fence: &Fence, + private_usage: DmaResvUsage, + extobj_usage: DmaResvUsage, + ) { + // SAFETY: This method takes a refcount on the fence, so it's only required to be valid for + // the duration of this method. If there is not enough space for the pre-allocated fence, + // then this leads to a BUG_ON() but does not trigger UB. + unsafe { + bindings::drm_gpuvm_resv_add_fence( + (*self.exec.get()).vm, + &raw mut (*self.exec.get()).exec, + fence.as_raw(), + private_usage as u32, + extobj_usage as u32, + ) + } + } +} + +#[pinned_drop] +impl<'vm, T: DriverGpuVm> PinnedDrop for GpuVmExec<'vm, T> { + fn drop(self: Pin<&mut Self>) { + // SAFETY: We hold the lock, so it's safe to unlock. + unsafe { bindings::drm_gpuvm_exec_unlock(self.exec.get()) }; + } +} -- 2.54.0.545.g6539524ca2-goog