From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 2EA5DCF58D5 for ; Fri, 20 Sep 2024 06:39:58 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id B165D6B0089; Fri, 20 Sep 2024 02:39:57 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id AC6086B008A; Fri, 20 Sep 2024 02:39:57 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 93F716B008C; Fri, 20 Sep 2024 02:39:57 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0010.hostedemail.com [216.40.44.10]) by kanga.kvack.org (Postfix) with ESMTP id 763756B0089 for ; Fri, 20 Sep 2024 02:39:57 -0400 (EDT) Received: from smtpin03.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 240461611FF for ; Fri, 20 Sep 2024 06:39:57 +0000 (UTC) X-FDA: 82584166434.03.CB7CEBD Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by imf09.hostedemail.com (Postfix) with ESMTP id DB8AE140011 for ; Fri, 20 Sep 2024 06:39:53 +0000 (UTC) Authentication-Results: imf09.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=NgsezK+r; spf=pass (imf09.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1726814280; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:dkim-signature; bh=TBTohzt93k/pWZ0gykhNCsmzYxdwEQp2uEI3E4E2c9E=; b=z58X+4MbZSSXdeRm9YeLT3Pfi5hk43wkA0NC8yEEvFLCJKkwXXVtMzs3BZkDgIr1mE8/qi g0LU0OKmhqPBRHa8B5ube31Yqjv+CuKCEOj/LyqXjBamHfWM3uDwL93iB9mj76J+fjoo0z tijP2YNjcNRNoTnU5XFGFD3UhFwowuY= ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1726814280; a=rsa-sha256; cv=none; b=ZVSszmBNEF8IXHwxqYw0FzePCjgdTDTZil2Acl0dG3oHgZxYjKssEw8Iv6IiGajnvF7rpi jZ0wYDjeS8w8qhavHgxxls6xpvuGIX3LnBuDK1Qt27bmnxuAPaJzdGU0/BPnt2atXPwx4X PtpqRxiGrOimDg4VZrT80dJCsrJKa60= ARC-Authentication-Results: i=1; imf09.hostedemail.com; dkim=pass header.d=redhat.com header.s=mimecast20190719 header.b=NgsezK+r; spf=pass (imf09.hostedemail.com: domain of david@redhat.com designates 170.10.129.124 as permitted sender) smtp.mailfrom=david@redhat.com; dmarc=pass (policy=none) header.from=redhat.com DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1726814393; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references:autocrypt:autocrypt; bh=TBTohzt93k/pWZ0gykhNCsmzYxdwEQp2uEI3E4E2c9E=; b=NgsezK+rJLMDrsOYEAbkJvxjSrFbaccsqigfnCyMd2OuyRv6amfqe6CCgeyYtr7RegubWr xJiKZryyT9YJSN60lsr3CV/skFGIbnufW+Ed1EO0gzULzRFL23aS/LkwJGnbjlpFCUtO/P nR9EWuhQ9M1bo2IwAmAeC91E+O/v1zk= Received: from mail-wr1-f70.google.com (mail-wr1-f70.google.com [209.85.221.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-413-6kpoxeRUOUmwSOjsQsT_Ag-1; Fri, 20 Sep 2024 02:39:50 -0400 X-MC-Unique: 6kpoxeRUOUmwSOjsQsT_Ag-1 Received: by mail-wr1-f70.google.com with SMTP id ffacd0b85a97d-374bb1e931cso1259639f8f.0 for ; Thu, 19 Sep 2024 23:39:50 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1726814389; x=1727419189; h=content-transfer-encoding:in-reply-to:organization:autocrypt:from :content-language:references:cc:to:subject:user-agent:mime-version :date:message-id:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=TBTohzt93k/pWZ0gykhNCsmzYxdwEQp2uEI3E4E2c9E=; b=B753beDTY+yLhDNdHMxxj3JHY2yGwjC1cBwgAM0g8Gk8ZC/BsZmjbVd9ShzU6Q1K3g xudO2HfZFck9WJ2SRjcwcm6RJoXDf8ZzqwduWuqVYMtiH4qB8QmoZvojd91WfrNTz4CT fE1h96UoxXUrL2FK6I+a19raXn9wBk765E2+IeTwkM6h0uHeEIi1KGdMwkNiOVkt4XQm 1RfAskdqLuJ704g0HzJxjYvys7ckJxCCELE79fpPC3oCbe2aX3FBxZyTRXrCJ8CrUtUo D9Y7N3pWgXbLyJYSUW2wjotWDRF7uJjgxdLnu8COyY8bONQpBdSjmP3QDdqiGMxXTz6b jGRA== X-Forwarded-Encrypted: i=1; AJvYcCUNbgkL4XiEAzlTTJbslC0SfGgxpZIFA9wFc96WHY0RK0K9s+pfNz5jSRUQQSAcQjJuT46QUK7FUg==@kvack.org X-Gm-Message-State: AOJu0YwCDVm/GL2SDkAZZKtpq7qTlx9jXQl971JQsVf4LK1sL7Uu6V0S xrmy1GhRArK48Djr7+X3raEMzXokJyZS89nsGQgcMmzp1lyXi2TdOOUBYPYIuAubjDHg0zgXC+h IjYoXGhYt2TH5Kza4D5NzMCjROheAhcOiy6+9qDdeK0rjgySg X-Received: by 2002:a5d:59a7:0:b0:374:bcfe:e73 with SMTP id ffacd0b85a97d-37a4159acb4mr1162101f8f.28.1726814389482; Thu, 19 Sep 2024 23:39:49 -0700 (PDT) X-Google-Smtp-Source: AGHT+IFNuEOmvvlI6JB+HKX1XlBcDemyM8s/TOWb5uNYzbgvjt8YB27WYVLkE+t5zNEfo0/pu/qk2A== X-Received: by 2002:a5d:59a7:0:b0:374:bcfe:e73 with SMTP id ffacd0b85a97d-37a4159acb4mr1162083f8f.28.1726814388959; Thu, 19 Sep 2024 23:39:48 -0700 (PDT) Received: from [192.168.21.234] (85-124-1-52.static.upcbusiness.at. [85.124.1.52]) by smtp.gmail.com with ESMTPSA id ffacd0b85a97d-378e78002afsm16854347f8f.75.2024.09.19.23.39.46 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 19 Sep 2024 23:39:47 -0700 (PDT) Message-ID: <4aad893a-f8ba-4b2e-bded-b01a35ec0a94@redhat.com> Date: Fri, 20 Sep 2024 08:39:49 +0200 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH] mm: Move set_pxd_safe() helpers from generic to platform To: Anshuman Khandual , linux-mm@kvack.org, akpm@linux-foundation.org Cc: Paul Walmsley , Palmer Dabbelt , Thomas Gleixner , Dave Hansen , Ryan Roberts , x86@kernel.org, linux-riscv@lists.infradead.org, linux-kernel@vger.kernel.org References: <20240920053017.2514920-1-anshuman.khandual@arm.com> From: David Hildenbrand Autocrypt: addr=david@redhat.com; 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 B3JfpUqcWwE7vUaYrHG1nw54pLUoPG6sAA7Mehl3nd4pZUALHwARAQABzSREYXZpZCBIaWxk ZW5icmFuZCA8ZGF2aWRAcmVkaGF0LmNvbT7CwZgEEwEIAEICGwMGCwkIBwMCBhUIAgkKCwQW AgMBAh4BAheAAhkBFiEEG9nKrXNcTDpGDfzKTd4Q9wD/g1oFAl8Ox4kFCRKpKXgACgkQTd4Q 9wD/g1oHcA//a6Tj7SBNjFNM1iNhWUo1lxAja0lpSodSnB2g4FCZ4R61SBR4l/psBL73xktp rDHrx4aSpwkRP6Epu6mLvhlfjmkRG4OynJ5HG1gfv7RJJfnUdUM1z5kdS8JBrOhMJS2c/gPf wv1TGRq2XdMPnfY2o0CxRqpcLkx4vBODvJGl2mQyJF/gPepdDfcT8/PY9BJ7FL6Hrq1gnAo4 3Iv9qV0JiT2wmZciNyYQhmA1V6dyTRiQ4YAc31zOo2IM+xisPzeSHgw3ONY/XhYvfZ9r7W1l pNQdc2G+o4Di9NPFHQQhDw3YTRR1opJaTlRDzxYxzU6ZnUUBghxt9cwUWTpfCktkMZiPSDGd KgQBjnweV2jw9UOTxjb4LXqDjmSNkjDdQUOU69jGMUXgihvo4zhYcMX8F5gWdRtMR7DzW/YE BgVcyxNkMIXoY1aYj6npHYiNQesQlqjU6azjbH70/SXKM5tNRplgW8TNprMDuntdvV9wNkFs 9TyM02V5aWxFfI42+aivc4KEw69SE9KXwC7FSf5wXzuTot97N9Phj/Z3+jx443jo2NR34XgF 89cct7wJMjOF7bBefo0fPPZQuIma0Zym71cP61OP/i11ahNye6HGKfxGCOcs5wW9kRQEk8P9 M/k2wt3mt/fCQnuP/mWutNPt95w9wSsUyATLmtNrwccz63XOwU0EVcufkQEQAOfX3n0g0fZz Bgm/S2zF/kxQKCEKP8ID+Vz8sy2GpDvveBq4H2Y34XWsT1zLJdvqPI4af4ZSMxuerWjXbVWb T6d4odQIG0fKx4F8NccDqbgHeZRNajXeeJ3R7gAzvWvQNLz4piHrO/B4tf8svmRBL0ZB5P5A 2uhdwLU3NZuK22zpNn4is87BPWF8HhY0L5fafgDMOqnf4guJVJPYNPhUFzXUbPqOKOkL8ojk CXxkOFHAbjstSK5Ca3fKquY3rdX3DNo+EL7FvAiw1mUtS+5GeYE+RMnDCsVFm/C7kY8c2d0G NWkB9pJM5+mnIoFNxy7YBcldYATVeOHoY4LyaUWNnAvFYWp08dHWfZo9WCiJMuTfgtH9tc75 7QanMVdPt6fDK8UUXIBLQ2TWr/sQKE9xtFuEmoQGlE1l6bGaDnnMLcYu+Asp3kDT0w4zYGsx 5r6XQVRH4+5N6eHZiaeYtFOujp5n+pjBaQK7wUUjDilPQ5QMzIuCL4YjVoylWiBNknvQWBXS lQCWmavOT9sttGQXdPCC5ynI+1ymZC1ORZKANLnRAb0NH/UCzcsstw2TAkFnMEbo9Zu9w7Kv AxBQXWeXhJI9XQssfrf4Gusdqx8nPEpfOqCtbbwJMATbHyqLt7/oz/5deGuwxgb65pWIzufa N7eop7uh+6bezi+rugUI+w6DABEBAAHCwXwEGAEIACYCGwwWIQQb2cqtc1xMOkYN/MpN3hD3 AP+DWgUCXw7HsgUJEqkpoQAKCRBN3hD3AP+DWrrpD/4qS3dyVRxDcDHIlmguXjC1Q5tZTwNB boaBTPHSy/Nksu0eY7x6HfQJ3xajVH32Ms6t1trDQmPx2iP5+7iDsb7OKAb5eOS8h+BEBDeq 3ecsQDv0fFJOA9ag5O3LLNk+3x3q7e0uo06XMaY7UHS341ozXUUI7wC7iKfoUTv03iO9El5f XpNMx/YrIMduZ2+nd9Di7o5+KIwlb2mAB9sTNHdMrXesX8eBL6T9b+MZJk+mZuPxKNVfEQMQ a5SxUEADIPQTPNvBewdeI80yeOCrN+Zzwy/Mrx9EPeu59Y5vSJOx/z6OUImD/GhX7Xvkt3kq Er5KTrJz3++B6SH9pum9PuoE/k+nntJkNMmQpR4MCBaV/J9gIOPGodDKnjdng+mXliF3Ptu6 3oxc2RCyGzTlxyMwuc2U5Q7KtUNTdDe8T0uE+9b8BLMVQDDfJjqY0VVqSUwImzTDLX9S4g/8 kC4HRcclk8hpyhY2jKGluZO0awwTIMgVEzmTyBphDg/Gx7dZU1Xf8HFuE+UZ5UDHDTnwgv7E th6RC9+WrhDNspZ9fJjKWRbveQgUFCpe1sa77LAw+XFrKmBHXp9ZVIe90RMe2tRL06BGiRZr jPrnvUsUUsjRoRNJjKKA/REq+sAnhkNPPZ/NNMjaZ5b8Tovi8C0tmxiCHaQYqj7G2rgnT0kt WNyWQQ== Organization: Red Hat In-Reply-To: <20240920053017.2514920-1-anshuman.khandual@arm.com> X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Language: en-US Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-Rspamd-Queue-Id: DB8AE140011 X-Stat-Signature: 4px76jefe6fbdcu6k46ar4a8uhbtd39w X-Rspamd-Server: rspam09 X-Rspam-User: X-HE-Tag: 1726814393-717052 X-HE-Meta: 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 Dc3gA7n/ 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 X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: List-Subscribe: List-Unsubscribe: On 20.09.24 07:30, Anshuman Khandual wrote: > set_pxd_safe() helpers that serve a specific purpose for both x86 and riscv > platforms, do not need to be in the common memory code. Otherwise they just > unnecessarily make the common API more complicated. This moves the helpers > from common code to platform instead. > > Cc: Paul Walmsley > Cc: Palmer Dabbelt > Cc: Thomas Gleixner > Cc: Dave Hansen > Cc: David Hildenbrand > Cc: Ryan Roberts > Cc: Andrew Morton > Cc: x86@kernel.org > Cc: linux-mm@kvack.org > Cc: linux-riscv@lists.infradead.org > Cc: linux-kernel@vger.kernel.org > Suggested-by: David Hildenbrand > Signed-off-by: Anshuman Khandual > --- > arch/riscv/include/asm/pgtable.h | 19 ++++++++++++++++ > arch/x86/include/asm/pgtable.h | 37 +++++++++++++++++++++++++++++++ > include/linux/pgtable.h | 38 -------------------------------- > 3 files changed, 56 insertions(+), 38 deletions(-) > > diff --git a/arch/riscv/include/asm/pgtable.h b/arch/riscv/include/asm/pgtable.h > index 089f3c9f56a3..39ca652c5ebe 100644 > --- a/arch/riscv/include/asm/pgtable.h > +++ b/arch/riscv/include/asm/pgtable.h > @@ -957,6 +957,25 @@ void misc_mem_init(void); > extern unsigned long empty_zero_page[PAGE_SIZE / sizeof(unsigned long)]; > #define ZERO_PAGE(vaddr) (virt_to_page(empty_zero_page)) > > +/* > + * Use set_p*_safe(), and elide TLB flushing, when confident that *no* > + * TLB flush will be required as a result of the "set". For example, use > + * in scenarios where it is known ahead of time that the routine is > + * setting non-present entries, or re-setting an existing entry to the > + * same value. Otherwise, use the typical "set" helpers and flush the > + * TLB. > + */ > +#define set_p4d_safe(p4dp, p4d) \ > +({ \ > + WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \ > + set_p4d(p4dp, p4d); \ > +}) > + > +#define set_pgd_safe(pgdp, pgd) \ > +({ \ > + WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \ > + set_pgd(pgdp, pgd); \ > +}) > #endif /* !__ASSEMBLY__ */ > > #endif /* _ASM_RISCV_PGTABLE_H */ > diff --git a/arch/x86/include/asm/pgtable.h b/arch/x86/include/asm/pgtable.h > index e39311a89bf4..fefb52bb6b4d 100644 > --- a/arch/x86/include/asm/pgtable.h > +++ b/arch/x86/include/asm/pgtable.h > @@ -1701,6 +1701,43 @@ bool arch_is_platform_page(u64 paddr); > #define arch_is_platform_page arch_is_platform_page > #endif > > +/* > + * Use set_p*_safe(), and elide TLB flushing, when confident that *no* > + * TLB flush will be required as a result of the "set". For example, use > + * in scenarios where it is known ahead of time that the routine is > + * setting non-present entries, or re-setting an existing entry to the > + * same value. Otherwise, use the typical "set" helpers and flush the > + * TLB. > + */ > +#define set_pte_safe(ptep, pte) \ > +({ \ > + WARN_ON_ONCE(pte_present(*ptep) && !pte_same(*ptep, pte)); \ > + set_pte(ptep, pte); \ > +}) > + > +#define set_pmd_safe(pmdp, pmd) \ > +({ \ > + WARN_ON_ONCE(pmd_present(*pmdp) && !pmd_same(*pmdp, pmd)); \ > + set_pmd(pmdp, pmd); \ > +}) > + > +#define set_pud_safe(pudp, pud) \ > +({ \ > + WARN_ON_ONCE(pud_present(*pudp) && !pud_same(*pudp, pud)); \ > + set_pud(pudp, pud); \ > +}) > + > +#define set_p4d_safe(p4dp, p4d) \ > +({ \ > + WARN_ON_ONCE(p4d_present(*p4dp) && !p4d_same(*p4dp, p4d)); \ > + set_p4d(p4dp, p4d); \ > +}) > + > +#define set_pgd_safe(pgdp, pgd) \ > +({ \ > + WARN_ON_ONCE(pgd_present(*pgdp) && !pgd_same(*pgdp, pgd)); \ > + set_pgd(pgdp, pgd); \ > +}) > #endif /* __ASSEMBLY__ */ I'm wondering if we can completely get rid of these, for example via: diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c index d8dbeac8b206..bc71c25930bb 100644 --- a/arch/x86/mm/init_64.c +++ b/arch/x86/mm/init_64.c @@ -79,10 +79,8 @@ DEFINE_POPULATE(pmd_populate_kernel, pmd, pte, init) static inline void set_##type1##_init(type1##_t *arg1, \ type2##_t arg2, bool init) \ { \ - if (init) \ - set_##type1##_safe(arg1, arg2); \ - else \ - set_##type1(arg1, arg2); \ + WARN_ON_ONCE(init && ##type1##_present(*arg1) && !##type1##_same(*arg1, arg2)); \ + set_##type1(arg1, arg2); \ } We might be able to handle the pgd_populate etc part similarly, possibly getting rid of the pgd_populate_safe etc as well. Assuming I don't miss anything important :) Ideally, we get rid of the macros here and just use inline functions ... -- Cheers, David / dhildenb