From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from flow-b2-smtp.messagingengine.com (flow-b2-smtp.messagingengine.com [202.12.124.137]) (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 E67A62EA468; Mon, 13 Jul 2026 15:40:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=202.12.124.137 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783957216; cv=none; b=igy6m2TuZZm2TUvoCUpZdOnqHo3OQ693TdxOLuQqiWXQKafXPeDETSaqLhHhyNcCBjOKYygXPO0cCz1q+JdI+QamKIhE3HW/BQVFJTbOweDFwqpUNrQ2abh0/y7nlDWcfphbHwU2oKJJnZma7mlwtb9n2x8Qmqpa3p3knT3Qb+U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783957216; c=relaxed/simple; bh=ShbWXJMsmb8dn/0HEdqhOGvBnjyFF1+YaJlMyjAKgVc=; h=MIME-Version:Date:From:To:Cc:Message-Id:In-Reply-To:References: Subject:Content-Type; b=cI1KLoPsV1/ZQNfMAYaj0JQaDSGaHwXJiCTa13c5IrxQM98u+sDIq8+2/forqIx4BlDl9ifgVUnWfIRDHLyp9iQZaHpgPiszxxdhwNuj2N8B63qI8glp05gavpb/AezBni4OivDSg4zQQOauFAkMYO/NNervAHS2xEk632O8A7U= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arndb.de; spf=pass smtp.mailfrom=arndb.de; dkim=pass (2048-bit key) header.d=arndb.de header.i=@arndb.de header.b=iW4sWePT; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b=ULQnKlUI; arc=none smtp.client-ip=202.12.124.137 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arndb.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arndb.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=arndb.de header.i=@arndb.de header.b="iW4sWePT"; dkim=pass (2048-bit key) header.d=messagingengine.com header.i=@messagingengine.com header.b="ULQnKlUI" Received: from phl-compute-04.internal (phl-compute-04.internal [10.202.2.44]) by mailflow.stl.internal (Postfix) with ESMTP id 1564713001CE; Mon, 13 Jul 2026 11:40:13 -0400 (EDT) Received: from phl-imap-05 ([10.202.2.95]) by phl-compute-04.internal (MEProxy); Mon, 13 Jul 2026 11:40:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=arndb.de; h=cc :cc:content-transfer-encoding:content-type:content-type:date :date:from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to; s=fm1; t=1783957212; x=1783964412; bh=63sZ2jVYn8LdZA7gH95m3khl+qIGq2b3k4vaJqArUP4=; b= iW4sWePT3v5RuiExrfF6A/7tVQ1jM80vt6+qaUuiSXX3xzi8TcKDoEMcLpC1Wycj YLGNDisot0aKbYabG11AiSqgAcEv+hchD7ePUn3Q7QegSB63SFitKnIvf8Ti5kJx Ow6wHq6FRA8HlIDy3+vSZ+o5LqkVyEACeWvE2KeOw18SdWdmOSIo/GUwP5W4SA6K mKTyKFVlWjx8My63P00L4s3EMdG8oh9p/ofSZoJXBBP4mbRVd+E+xZ0mPRjcLmAt WVCZZZf+RPZDpr59W8GBdVkmu2RsFbrHEETXg75tSH6h1O4S9IWJHkZnYe4bDtPg 0VPe9WYzzmoe5YVydhyDvQ== DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d= messagingengine.com; h=cc:cc:content-transfer-encoding :content-type:content-type:date:date:feedback-id:feedback-id :from:from:in-reply-to:in-reply-to:message-id:mime-version :references:reply-to:subject:subject:to:to:x-me-proxy :x-me-sender:x-me-sender:x-sasl-enc; s=fm2; t=1783957212; x= 1783964412; bh=63sZ2jVYn8LdZA7gH95m3khl+qIGq2b3k4vaJqArUP4=; b=U LQnKlUIywRVFQz2T48udoC33TJAoCXdIAZSeuGP1N0ZPr7fcEG7S0TpEcaVnVn+c G/SRa5VYTCQiMflK18sIgpnNhTHIZmCtVUou1s85jLllfrcplhXWmtZKcOfuxqKz 9OQxUpM9VVkLqu+9JHpcM1AfRqAyklLXOkI+caA/S4eOsPJ5KLTh7w5jSxlilDkX 8RFtQB2RucnR3YZ8hSAs6eIBOegmwS2ddCbQF+9kknh7pkz44rxlTKTyBe+AZOQ/ ngdVzQah4hXX7/v48Y2rsKaJyDh0/T4dziQmFdciXJJWCTgGF//fvmhuxjpfTstx j1m7omfM4V4qrGYPJq3nw== X-ME-Sender: X-ME-Proxy-Cause: dmFkZTGiBa7nyoJvLHpB9RMkM4BhBJPI163JjTDxEnYj0dxDppPFOS0iQb76r61dIHKZoH doew5BVKOzJl0BxEjQHPQAXL339ylWw9vfj91e6+EvGpmugWu4l6FgfHGT8veDQl14YlPk azrbgOlYeMoe8q4O6tOdPBWZ3gkfzjXB3MpP5ZSS4pVL3cODDv5o9sdlZZ82AnAYTD4dX1 ZFEmxiB6y+c1WjQCjWbG2Tuy/F+AydS2qapXYfVj/nzoLQFdxYjff2W121CSyjD96Jqz/I RYFG+TB6hnYHG9pcozXzRhRj+7dUC7mbo9HM5um7P+xMaKCVbsxuHzrZLXSTZvkQV2DqfL ymeLwexCZPabJK55d5sxK/21hOkUFoUb+ExTnzslr1kLuW1SR9WWu7ZvVZMwIF4IWgoi/o j/VpQgVmgwhpVLtp5lgzTBmrTiT5gbnZ7Q7GXYbiO8QeTCwgQIZC6c35txMZjS6TWKAANZ lL+3RIdvFvspxp+zwMu1615CC5kCx8DC7tXphYZD0u/gz62IOXC21Cm6XtX7xtSF81yIbe SwtTDOBQfx6km50Rqc7jckoTHgvu2LsUahDrxwpgeQTFkFeEql548ztZEJ0FWTv/essIyv UwEUdfW3DUphCt4+X7M4Fr0an8HZRkO0QIWnSfi10X3VjRXmi2o6LGa4b21g X-ME-Proxy: Feedback-ID: i56a14606:Fastmail Received: by mailuser.phl.internal (Postfix, from userid 501) id E2258182008C; Mon, 13 Jul 2026 11:40:08 -0400 (EDT) X-Mailer: MessagingEngine.com Webmail Interface Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-ThreadId: ASU80-mPZ9gg Date: Mon, 13 Jul 2026 17:38:53 +0200 From: "Arnd Bergmann" To: "Yeoreum Yun" , linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, Linux-Arch , kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, x86@kernel.org, linux-mm@kvack.org, kasan-dev@googlegroups.com, "linux-csky@vger.kernel.org" , linux-m68k@lists.linux-m68k.org, "linux-openrisc@vger.kernel.org" Cc: "David Hildenbrand (Red Hat)" , "Russell King" , "Andrew Morton" , "Ankur Arora" , "Mike Rapoport" , "Magnus Lindholm" , "Christophe Leroy" , "Klara Modin" , "Huacai Chen" , "WANG Xuerui" , "Kirill A. Shutemov" , zhangtianyang@loongson.cn, wangyuli@aosc.io, "Thomas Bogendoerfer" , "Lorenzo Stoakes" , "Jason Gunthorpe" , "Catalin Marinas" , "Will Deacon" , "Ryan Roberts" , "Pasha Tatashin" , "Rohan McLure" , "Baolin Wang" , "Tejun Heo" , "Kevin Brodsky" , "Anup Patel" , atish.patra@linux.dev, "Paul Walmsley" , "Palmer Dabbelt" , "Albert Ou" , "Alexandre Ghiti" , "Dave Hansen" , "Andy Lutomirski" , "Peter Zijlstra" , "Thomas Gleixner" , "Ingo Molnar" , "Borislav Petkov" , "H. Peter Anvin" , "Johannes Weiner" , "Michal Hocko" , qi.zheng@linux.dev, "Shakeel Butt" , "Kairui Song" , "Barry Song" , "Axel Rasmussen" , "Yuanchu Xie" , "Wei Xu" , "Andrey Ryabinin" , "Alexander Potapenko" , "Andrey Konovalov" , "Dmitry Vyukov" , "Vincenzo Frascino" , "Anshuman Khandual" , "Yang Shi" , chaitanyas.prakash@arm.com, "Ard Biesheuvel" , guoren , yang.li85200@gmail.com, "Alexander Viro" , "Dinh Nguyen" , "schuster.simon@siemens-energy.com" , "Vivian Wang" , junhui.liu@pigmoral.tech, "Muchun Song" , "Vishal Moola (Oracle)" , "Nam Cao" , "Pavel Machek" , djbw@kernel.org, yu-cheng.yu@intel.com, "Baolu Lu" , "Jonathan Cameron" , "Coiby Xu" , "Andreas Larsson" , "Liam R. Howlett" , "Vlastimil Babka (SUSE)" , "Suren Baghdasaryan" , "Michal Hocko" , "Geert Uytterhoeven" , "Stafford Horne" , "Jonas Bonn" , "Stefan Kristiansson" Message-Id: In-Reply-To: <20260713135614.1618183-3-yeoreum.yun@arm.com> References: <20260713135614.1618183-1-yeoreum.yun@arm.com> <20260713135614.1618183-3-yeoreum.yun@arm.com> Subject: Re: [RFC PATCH 02/34] ARM: mm: make 2-level pgd_t a scalar Content-Type: text/plain Content-Transfer-Encoding: 7bit On Mon, Jul 13, 2026, at 15:55, Yeoreum Yun wrote: > From: "David Hildenbrand (Arm)" > > We don't want pgd_t to be an array, as it prohibits returning it from a > function, like pgdp_get(). What should pgdp_get() return on ARM 2-stage page tables then? Does it return just the first entry or concatenate the two? > +typedef u64 pgdval_t; > +static inline pmdval_t pgd_val(pgd_t pgd) > +{ > + return (*(pmdval_t (*)[2])&pgd)[0]; > +} This could use a comment to explain what this actually returns and why the second entry is discarded. Arnd