From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 3E69E3FFFA7 for ; Tue, 25 Aug 2026 15:52:29 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787673150; cv=none; b=m/bK/Bn0/1NEk5/RnA24r7ayo242GcdRi0V/R2OUrLC1kW9nzFKhwQyQ/t8vkYtcocqVv5faOm83iKwWwfm3lSci7zXNpjz6m8jvmOdLX06seixsbqYwYlf9XwAS8gk9YbWBifRRp8jAR/yhsUH4weoJN0AKNDksRZ8Qt3j1/68= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1787673150; c=relaxed/simple; bh=Qn0vc91SuaCobDiC9ryT5Cz+3s634glHMssZ3BYQIR8=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=AqCXA+9IkyzwEVBiQsJIisF9+UXlVThLTegnrM9A09z3sebxlFLJV++ZJWEU3DMJLcM0OC4H/cxCHl/31PoyIaK9gnrWp+szfLT38DVdH7L+/LDMxEaECMFpOGhF//JWO7Z0X1bB0HlfxJjeTDg4xXq4JSca7TnlzPRE8yQXCrc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=oI2Zk6aP; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="oI2Zk6aP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F23831F000E9; Tue, 25 Aug 2026 15:52:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1787673149; bh=ZXk+8AC9tMdedJd5dFONsAVyXoD+TKxKvDZGwEn5NWc=; h=Date:Subject:To:Cc:References:From:In-Reply-To; b=oI2Zk6aPcKkinmBuXHsTZ0lPJ4zsulOOd+7Q8ro+fhQrEaP7SevErk++Sfea1CJHw RTBp0SQ0bSsWlDvvcmXRJ0fkpWy7wuwH18ye7GWtdS442r3bFLRANmLUtv0GBoMf4k loic+XmPvhLSIQlKZS3Otbd5tQDJe9tlzll4BHZzYLDH00tWHwOKOQdrmEdE8C2tHa E6Y2ySQ+ywO71VP3c7v9uDXbV9Fo+xdyoP2wyUOH9bSLvYStTgwwTNsEmeqk+ZddGd nKb4s3xFXsLeVwCfjLCXrP20slkDnhpBM2ZVH0Vs0QxetWz+wIrI6DkAcu9PjWZm86 UGrGKqcDgz/WA== Message-ID: Date: Tue, 25 Aug 2026 17:52:20 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v6 2/3] arm64/mm: add set_direct_map_ro_noflush() To: Xueyuan Chen , akpm@linux-foundation.org Cc: ljs@kernel.org, usama.arif@linux.dev, catalin.marinas@arm.com, will@kernel.org, linux-arm-kernel@lists.infradead.org, tglx@kernel.org, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, x86@kernel.org, hpa@zytor.com, rppt@kernel.org, ryan.roberts@arm.com, ziy@nvidia.com, baohua@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, Lance Yang References: <20260730090647.2401252-1-xueyuan.chen21@gmail.com> <20260730090647.2401252-3-xueyuan.chen21@gmail.com> From: "David Hildenbrand (Arm)" Content-Language: en-US Autocrypt: addr=david@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit On 7/30/26 11:06, Xueyuan Chen wrote: > Implement set_direct_map_ro_noflush() for arm64 with update_range_prot() on > the linear map, setting PTE_RDONLY and clearing PTE_WRITE. Keep the > existing can_set_direct_map() guard and leave TLB invalidation to the > caller. > > Co-developed-by: Lance Yang > Signed-off-by: Lance Yang > Signed-off-by: Xueyuan Chen > --- > arch/arm64/include/asm/set_memory.h | 2 ++ > arch/arm64/mm/pageattr.c | 10 ++++++++++ > 2 files changed, 12 insertions(+) > > diff --git a/arch/arm64/include/asm/set_memory.h b/arch/arm64/include/asm/set_memory.h > index 90f61b17275e..7083260303c3 100644 > --- a/arch/arm64/include/asm/set_memory.h > +++ b/arch/arm64/include/asm/set_memory.h > @@ -14,6 +14,8 @@ int set_memory_valid(unsigned long addr, int numpages, int enable); > int set_direct_map_invalid_noflush(struct page *page); > int set_direct_map_default_noflush(struct page *page); > int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid); > +int set_direct_map_ro_noflush(const void *addr, unsigned long nr_pages); > +#define set_direct_map_ro_noflush set_direct_map_ro_noflush > bool kernel_page_present(struct page *page); > > int set_memory_encrypted(unsigned long addr, int numpages); > diff --git a/arch/arm64/mm/pageattr.c b/arch/arm64/mm/pageattr.c > index ce035e1b4eaf..c51236b61651 100644 > --- a/arch/arm64/mm/pageattr.c > +++ b/arch/arm64/mm/pageattr.c > @@ -365,6 +365,16 @@ int set_direct_map_valid_noflush(struct page *page, unsigned nr, bool valid) > return set_memory_valid(addr, nr, valid); > } > > +int set_direct_map_ro_noflush(const void *addr, unsigned long nr_pages) > +{ > + if (!can_set_direct_map()) > + return 0; > + > + return update_range_prot((unsigned long)addr, PAGE_SIZE * nr_pages, > + __pgprot(PTE_RDONLY), > + __pgprot(PTE_WRITE)); > +} > + > #ifdef CONFIG_DEBUG_PAGEALLOC > /* > * This is - apart from the return value - doing the same We'll need an ACK from arm64 maintaines. To me this looks good. -- Cheers, David