From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sea.source.kernel.org (sea.source.kernel.org [172.234.252.31]) (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 B3DA443A801 for ; Wed, 15 Jul 2026 09:42:02 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=172.234.252.31 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784108527; cv=none; b=ub/UEVsNybWMFAhPM+gLurZsQfDGR0o3aOz/R/SdXCcyV28tiGzYe8fytH8pMw6MXm4B1kIz2qAW64PUgZhvGekUzde97NXMqTrp3FbzbZc0Nvzcr7aKoWvoPDX1gag1sTLRyis7+WnFz6VdknRVvYAHh/3iOXWmUgpFj39olkE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1784108527; c=relaxed/simple; bh=MTIXqsT8IK4LgAKnrdmFWqR2jWtIGSZsez8rl9WZZWk=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=rDXi+qAFJAFuraQpDAFvO14X35zc7+kjJQ0BlKcXSw1W2DtaYkp45Co57ZDuB+BcbUwQqaWc6yuLTIUmg3Z6icLVQq97KT2JLU+MP6QVOB/uA2Sw0bz2iXlv0MTSJx2EeHkRLzAqcDOIOIeb+hNyLd4HKG0jLvT8xzfQWoAVMCo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org; spf=pass smtp.mailfrom=kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BuGz//px; arc=none smtp.client-ip=172.234.252.31 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=kernel.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=kernel.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BuGz//px" Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) by sea.source.kernel.org (Postfix) with ESMTP id 2912A40826; Wed, 15 Jul 2026 09:41:57 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 2CF8E1F000E9; Wed, 15 Jul 2026 09:41:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1784108517; bh=OsOrjOhnWHROAiL5jDixjdTy01yhp26YPrQZj+ZKGmw=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=BuGz//px8JYdlH1ROvcuFbUOrHqWr7Rai0ClmU5vVCqM4fdwBLoq9Vk7jfZQEhE8o IrnCDnGAkDVIoIFoRjcmZxlwdPG6OC+YipvyBE1odgnKvHKfNNwCh2XB2buwJGPS5R iBefsX/TKhJhR9hmzL7dGwZoJU/Ji9SN05RgUmsskxXD435oXeBrcPkdG2DFhsu4vj +e3aJz8AcS0lF7M/snH51Xce3ywkaeqf7dD4P6hu8Nxym6mLslJ6h4MrI357cw7O81 XRBPOHup+Txi7+dBCWr1PZMqToL9uE9MZabdtccbuNt9Ibi4HCKPDlvi2/hKJAx9qB MWWxwbBRaMUlw== Message-ID: <7abd77fd-6c3e-4560-8e68-cbcde48264f5@kernel.org> Date: Wed, 15 Jul 2026 11:41:41 +0200 Precedence: bulk X-Mailing-List: linux-m68k@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH 02/34] ARM: mm: make 2-level pgd_t a scalar To: Arnd Bergmann , 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: 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 References: <20260713135614.1618183-1-yeoreum.yun@arm.com> <20260713135614.1618183-3-yeoreum.yun@arm.com> <4a0f9161-961e-47f9-8672-9a06e52fefea@app.fastmail.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; keydata= xsFNBFXLn5EBEAC+zYvAFJxCBY9Tr1xZgcESmxVNI/0ffzE/ZQOiHJl6mGkmA1R7/uUpiCjJ dBrn+lhhOYjjNefFQou6478faXE6o2AhmebqT4KiQoUQFV4R7y1KMEKoSyy8hQaK1umALTdL QZLQMzNE74ap+GDK0wnacPQFpcG1AE9RMq3aeErY5tujekBS32jfC/7AnH7I0v1v1TbbK3Gp XNeiN4QroO+5qaSr0ID2sz5jtBLRb15RMre27E1ImpaIv2Jw8NJgW0k/D1RyKCwaTsgRdwuK Kx/Y91XuSBdz0uOyU/S8kM1+ag0wvsGlpBVxRR/xw/E8M7TEwuCZQArqqTCmkG6HGcXFT0V9 PXFNNgV5jXMQRwU0O/ztJIQqsE5LsUomE//bLwzj9IVsaQpKDqW6TAPjcdBDPLHvriq7kGjt WhVhdl0qEYB8lkBEU7V2Yb+SYhmhpDrti9Fq1EsmhiHSkxJcGREoMK/63r9WLZYI3+4W2rAc UucZa4OT27U5ZISjNg3Ev0rxU5UH2/pT4wJCfxwocmqaRr6UYmrtZmND89X0KigoFD/XSeVv jwBRNjPAubK9/k5NoRrYqztM9W6sJqrH8+UWZ1Idd/DdmogJh0gNC0+N42Za9yBRURfIdKSb B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzS5EYXZpZCBIaWxk ZW5icmFuZCAoQ3VycmVudCkgPGRhdmlkQGtlcm5lbC5vcmc+wsGQBBMBCAA6AhsDBQkmWAik AgsJBBUKCQgCFgICHgUCF4AWIQQb2cqtc1xMOkYN/MpN3hD3AP+DWgUCaYJt/AIZAQAKCRBN 3hD3AP+DWriiD/9BLGEKG+N8L2AXhikJg6YmXom9ytRwPqDgpHpVg2xdhopoWdMRXjzOrIKD g4LSnFaKneQD0hZhoArEeamG5tyo32xoRsPwkbpIzL0OKSZ8G6mVbFGpjmyDLQCAxteXCLXz ZI0VbsuJKelYnKcXWOIndOrNRvE5eoOfTt2XfBnAapxMYY2IsV+qaUXlO63GgfIOg8RBaj7x 3NxkI3rV0SHhI4GU9K6jCvGghxeS1QX6L/XI9mfAYaIwGy5B68kF26piAVYv/QZDEVIpo3t7 /fjSpxKT8plJH6rhhR0epy8dWRHk3qT5tk2P85twasdloWtkMZ7FsCJRKWscm1BLpsDn6EQ4 jeMHECiY9kGKKi8dQpv3FRyo2QApZ49NNDbwcR0ZndK0XFo15iH708H5Qja/8TuXCwnPWAcJ DQoNIDFyaxe26Rx3ZwUkRALa3iPcVjE0//TrQ4KnFf+lMBSrS33xDDBfevW9+Dk6IISmDH1R HFq2jpkN+FX/PE8eVhV68B2DsAPZ5rUwyCKUXPTJ/irrCCmAAb5Jpv11S7hUSpqtM/6oVESC 3z/7CzrVtRODzLtNgV4r5EI+wAv/3PgJLlMwgJM90Fb3CB2IgbxhjvmB1WNdvXACVydx55V7 LPPKodSTF29rlnQAf9HLgCphuuSrrPn5VQDaYZl4N/7zc2wcWM7BTQRVy5+RARAA59fefSDR 9nMGCb9LbMX+TFAoIQo/wgP5XPyzLYakO+94GrgfZjfhdaxPXMsl2+o8jhp/hlIzG56taNdt VZtPp3ih1AgbR8rHgXw1xwOpuAd5lE1qNd54ndHuADO9a9A0vPimIes78Hi1/yy+ZEEvRkHk /kDa6F3AtTc1m4rbbOk2fiKzzsE9YXweFjQvl9p+AMw6qd/iC4lUk9g0+FQXNdRs+o4o6Qvy iOQJfGQ4UcBuOy1IrkJrd8qq5jet1fcM2j4QvsW8CLDWZS1L7kZ5gT5EycMKxUWb8LuRjxzZ 3QY1aQH2kkzn6acigU3HLtgFyV1gBNV44ehjgvJpRY2cC8VhanTx0dZ9mj1YKIky5N+C0f21 zvntBqcxV0+3p8MrxRRcgEtDZNav+xAoT3G0W4SahAaUTWXpsZoOecwtxi74CyneQNPTDjNg azHmvpdBVEfj7k3p4dmJp5i0U66Onmf6mMFpArvBRSMOKU9DlAzMi4IvhiNWjKVaIE2Se9BY FdKVAJaZq85P2y20ZBd08ILnKcj7XKZkLU5FkoA0udEBvQ0f9QLNyyy3DZMCQWcwRuj1m73D sq8DEFBdZ5eEkj1dCyx+t/ga6x2rHyc8Sl86oK1tvAkwBNsfKou3v+jP/l14a7DGBvrmlYjO 59o3t6inu6H7pt7OL6u6BQj7DoMAEQEAAcLBfAQYAQgAJgIbDBYhBBvZyq1zXEw6Rg38yk3e EPcA/4NaBQJonNqrBQkmWAihAAoJEE3eEPcA/4NaKtMQALAJ8PzprBEXbXcEXwDKQu+P/vts IfUb1UNMfMV76BicGa5NCZnJNQASDP/+bFg6O3gx5NbhHHPeaWz/VxlOmYHokHodOvtL0WCC 8A5PEP8tOk6029Z+J+xUcMrJClNVFpzVvOpb1lCbhjwAV465Hy+NUSbbUiRxdzNQtLtgZzOV Zw7jxUCs4UUZLQTCuBpFgb15bBxYZ/BL9MbzxPxvfUQIPbnzQMcqtpUs21CMK2PdfCh5c4gS sDci6D5/ZIBw94UQWmGpM/O1ilGXde2ZzzGYl64glmccD8e87OnEgKnH3FbnJnT4iJchtSvx yJNi1+t0+qDti4m88+/9IuPqCKb6Stl+s2dnLtJNrjXBGJtsQG/sRpqsJz5x1/2nPJSRMsx9 5YfqbdrJSOFXDzZ8/r82HgQEtUvlSXNaXCa95ez0UkOG7+bDm2b3s0XahBQeLVCH0mw3RAQg r7xDAYKIrAwfHHmMTnBQDPJwVqxJjVNr7yBic4yfzVWGCGNE4DnOW0vcIeoyhy9vnIa3w1uZ 3iyY2Nsd7JxfKu1PRhCGwXzRw5TlfEsoRI7V9A8isUCoqE2Dzh3FvYHVeX4Us+bRL/oqareJ CIFqgYMyvHj7Q06kTKmauOe4Nf0l0qEkIuIzfoLJ3qr5UyXc2hLtWyT9Ir+lYlX9efqh7mOY qIws/H2t In-Reply-To: <4a0f9161-961e-47f9-8672-9a06e52fefea@app.fastmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/15/26 08:15, Arnd Bergmann wrote: > On Mon, Jul 13, 2026, at 15:55, Yeoreum Yun wrote: > >> typedef pteval_t pte_t; >> typedef pmdval_t pmd_t; >> -typedef pmdval_t pgd_t[2]; >> +typedef pgdval_t pgd_t; >> typedef pteval_t pgprot_t; >> > > Just noticed one more issue here, I think this will break these > two macros that now access four entries instead of two: > > #define copy_pmd(pmdpd,pmdps) \ > do { \ > pmdpd[0] = pmdps[0]; \ > pmdpd[1] = pmdps[1]; \ > flush_pmd_entry(pmdpd); \ > } while (0) > > #define pmd_clear(pmdp) \ > do { \ > pmdp[0] = __pmd(0); \ > pmdp[1] = __pmd(0); \ > clean_pmd_entry(pmdp); \ > } while (0) Yeah, let me look into it now that I understand roughly which tricks ARM is playing there :) -- Cheers, David