From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-wm1-f74.google.com (mail-wm1-f74.google.com [209.85.128.74]) (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 19BB42417C3 for ; Tue, 25 Nov 2025 09:24:01 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.128.74 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764062644; cv=none; b=K8pN/ejcGSqcNqr3XJn9KNSWqYlhRcdjw/rELcKc8yRoFg7+EH3JD/kRNgVHc1XwV2p4I6ewTLMfmcvcy1xe95S22LjRTBT7DnF1GqzRiBjyyx9o4Gndn6NR33UKxWfg2JtrTpO52ZKhwuPaRva80aQcrEjtwJ+dnlH2SiBuD8Y= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764062644; c=relaxed/simple; bh=lQaMeggpSibkoVsDq5NZm9Spvse5PL55lVnAwvvcJWs=; h=Date:In-Reply-To:Mime-Version:References:Message-ID:Subject:From: To:Cc:Content-Type; b=U1B3Ofj6nIP7CHW68lQzoy+QHYxF46Xjgf/2M95WKQ91oeH3fSULGk2PrMEbuT+bgZxyC0zhq0uqv3MzdoLn3zUNzoS9kZy8hWh7t/Fczk0IAp007NlUOZsd3P2QKv1ZE4Nrdocfelnrcm6gkwu00Xy1OmiicqTarK5yjk4sfGQ= 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=u49vRKDD; arc=none smtp.client-ip=209.85.128.74 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="u49vRKDD" Received: by mail-wm1-f74.google.com with SMTP id 5b1f17b1804b1-47799717212so41488775e9.3 for ; Tue, 25 Nov 2025 01:24:01 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20230601; t=1764062640; x=1764667440; 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=Gdct6hRNMC2a33F1SDQTUemoosYNL7hA0Cpixkq+5aE=; b=u49vRKDD3X97fgMtQXNTe8jO08fDrin31VucCBIMpm6AynLGjygg9U4WLmlv/XrEck LqDblpRGeJ3t0WE/Uxagoco0UZwuBTdPo25uERoMLE7chF9meRdI67M3llxt6ddqYj4T u47k5bdrbju4VeJ1amSGqckVi+Ndi2FXBsMuX19LErzDcLiOUmT29nmBRM50uzq0axKb o5USn40cYanfdGaEXe/Pg4c0H/dRqUaAhFxtLAf0hPpied44AGfLaynUH+v5o1eYYKen npMUexQISR8TWTzHPjBUOcUTDlYL+LT96y7YHAeZCN1T4xqSLDYNzmphakTkD/A3ANBQ lC1Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1764062640; x=1764667440; 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=Gdct6hRNMC2a33F1SDQTUemoosYNL7hA0Cpixkq+5aE=; b=OZ+IP52fwc6+8h1BKB4LAl79r0ZFi/gLbP/BjdJWwro1hvr01f2Y/1VPK0oa+fnb5L pbXpsGyRcjR0XHhg1OkWrC+TBOmEXWmORuR6WX7StG8HFUsOU2bLPrskMalGupjeOA9L cvALlBT5Y8lgLD0m+RWtZyUdcHoHX8RI4r9A6TvcbuNVj1926bvsHxzVsXlaxVQ7Pw7+ sRAow/pWONTqrOwIyMVC9XSLUHdb7NTngbvg1w7vpY2WRsF6edAkvgD1n4/UdjwAXsJp Rch6hCW+pe3r7U1TVzF7PQ34M4e/O7wVWLfBNutOLnDaNuYfZ/WmgE8TUBwSS4czoLLR BBCg== X-Forwarded-Encrypted: i=1; AJvYcCVXF9h6ejAQ4R8iwD9pMU35msMYS6heSrr7qzHxvQzuKmYJVFvogH7tQW/D9xmkpglR7Dvy/v7HzP/s0mcjSA==@vger.kernel.org X-Gm-Message-State: AOJu0Yzf6iuIpyKZIuc4YzuFcaaQzNcoV4V0XQHjMPS5F+sT17SXBLHY pAhSY3mi0IQStdwVDqx+VBo77ptl9zmeJckC3EFAFNItbA6ChMjP0vVKUFJVq7MrMuAI3QyYQcd 6TmDSs3eIwcDzscHpzQ== X-Google-Smtp-Source: AGHT+IGgXo8y5EZjUDnBVwTOnyAZJVGtwWGypNxUeeXb63lWRcPTjmeoWUCMdN3xat5RPemCnmCh9NC4gbF2QE0= X-Received: from wmih8.prod.google.com ([2002:a05:600c:1448:b0:477:a2ad:bddc]) (user=aliceryhl job=prod-delivery.src-stubby-dispatcher) by 2002:a05:600c:3588:b0:477:bcb:24cd with SMTP id 5b1f17b1804b1-477c11179ffmr162794335e9.22.1764062640310; Tue, 25 Nov 2025 01:24:00 -0800 (PST) Date: Tue, 25 Nov 2025 09:23:59 +0000 In-Reply-To: <98227EBD-92F7-40FC-A5A4-3FF3780FB2CB@bne-home.net> Precedence: bulk X-Mailing-List: rust-for-linux@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: Mime-Version: 1.0 References: <98227EBD-92F7-40FC-A5A4-3FF3780FB2CB@bne-home.net> Message-ID: Subject: Re: [PATCH 1/1] drm: nova: Align GEM memory allocation to system page size From: Alice Ryhl To: bshephar@bne-home.net Cc: dakr@kernel.org, acourbot@nvidia.com, joelagnelf@nvidia.com, jhubbard@nvidia.com, airlied@gmail.com, rust-for-linux@vger.kernel.org, nouveau@lists.freedesktop.org, brendan.shephard@gmail.com Content-Type: text/plain; charset="utf-8" On Fri, Nov 21, 2025 at 02:04:28PM +1000, bshephar@bne-home.net wrote: > Use page::page_align for GEM object memory allocation to ensure the > allocation is page aligned. This ensures that the allocation is page > aligned with the system in cases where 4096 is not the default. > For example on 16k or 64k aarch64 systems this allocation should be > aligned accordingly. > > Signed-off-by: Brendan Shephard > --- > drivers/gpu/drm/nova/gem.rs | 11 ++++++++--- > 1 file changed, 8 insertions(+), 3 deletions(-) > > diff --git a/drivers/gpu/drm/nova/gem.rs b/drivers/gpu/drm/nova/gem.rs > index 2760ba4f3450..a07e922e25ef 100644 > --- a/drivers/gpu/drm/nova/gem.rs > +++ b/drivers/gpu/drm/nova/gem.rs > @@ -3,6 +3,10 @@ > use kernel::{ > drm, > drm::{gem, gem::BaseObject}, > + page::{ > + page_align, > + PAGE_SIZE, // > + }, > prelude::*, > sync::aref::ARef, > }; > @@ -27,12 +31,13 @@ fn new(_dev: &NovaDevice, _size: usize) -> impl PinInit { > impl NovaObject { > /// Create a new DRM GEM object. > pub(crate) fn new(dev: &NovaDevice, size: usize) -> Result>> { > - let aligned_size = size.next_multiple_of(1 << 12); > - > - if size == 0 || size > aligned_size { > + // Check for 0 size or potential usize overflow before calling page_align > + if size == 0 || size > usize::MAX - PAGE_SIZE + 1 { Maybe this should use isize::MAX as the maximum size instead? That's a pretty common maximum size for allocations in Rust and big enough for everyone. Alice > return Err(EINVAL); > } > > + let aligned_size = page_align(size); > + > gem::Object::new(dev, aligned_size) > } > > --