From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 7C42C47798A; Thu, 24 Sep 2026 12:23:12 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790252594; cv=none; b=D8xDpyvKNBi6mIJgbafYb66FrjkFMPUl0CbAzgBTe0b1htN6tJ2xm2p5XExWMtq29Bdu/2HW9FM8wZpYTbdocS26fZWFlbNNuSiSdXTplDHDdKuML1AwLGaF86iMX6WXAoQeE90LczfuxqOznMDKWyoIO03Jw1+fFDNfscKYPmE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1790252594; c=relaxed/simple; bh=6RiiprozYmDqlvYaiBGVz8TgL+fPnC8hgT90X3WinvY=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=s/hdUkE0HqkzI9UTMLQWFT8oxMRmEG6gRbWtJKYkoUAkXhPG7jPZb17KvVrA/iENAQSvISkqzkvjiQAs7+s4cCDoBriNKAl8eeVnSW4db/5HxoMB9RDGvUYrZJl2BHnY16qbOU87tZZ0/wLJNt2JTMCHJDcjkvIhPNrwMHsU8qc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=VL2sSYmX; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="VL2sSYmX" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 500FF152B; Thu, 24 Sep 2026 05:23:08 -0700 (PDT) Received: from [10.57.83.110] (unknown [10.57.83.110]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9C5E13F86C; Thu, 24 Sep 2026 05:23:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1790252591; bh=6RiiprozYmDqlvYaiBGVz8TgL+fPnC8hgT90X3WinvY=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=VL2sSYmXUX7Oe1yYpOSWfGPfVESz/LeVs6qkwp1c7ZID3I/9r7KlqFgNVuLSNzCV9 EeeFBxAp7V1h25U7R5kNeEy+s+vXRYgfbFAS4N86NhOR8+pYZ62Ffl8B6WkVroZ3GM 9+ukhLWw1BwYdiBWnZvL8p/PGxHli+OEN3B4LpSg= Message-ID: Date: Thu, 24 Sep 2026 13:23:05 +0100 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 v2 3/6] arm64: use hw_pte_val for HW PTE loads and stores To: Muhammad Usama Anjum , Catalin Marinas , Will Deacon , Mark Rutland , Ard Biesheuvel , Ilias Apalodimas , Andrey Ryabinin , Alexander Potapenko , Andrey Konovalov , Dmitry Vyukov , Vincenzo Frascino , Andrew Morton , David Hildenbrand , Lorenzo Stoakes , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, linux-efi@vger.kernel.org, kasan-dev@googlegroups.com, linux-mm@kvack.org References: <20260922-pte0_arm-v2-0-a3f1ddff0a8a@arm.com> <20260922-pte0_arm-v2-3-a3f1ddff0a8a@arm.com> From: Ryan Roberts Content-Language: en-GB In-Reply-To: <20260922-pte0_arm-v2-3-a3f1ddff0a8a@arm.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 22/09/2026 18:31, Muhammad Usama Anjum wrote: > __ptep_get() returns a SW PTE value, while __set_pte_nosync() accepts > one. When HW PTE storage uses a distinct hw_pte_t, reading or writing > *ptep as a pte_t no longer satisfies those interfaces. > > Use hw_pte_val() to expose the pteval_t stored in either the hw_pte_t > wrapper or its pte_t alias. __set_pte_nosync() writes pte_val(pte) to > that storage, while __ptep_get() reads it and reconstructs a pte_t with > __pte(). > > This avoids imposing a generic conversion interface between HW and SW > PTE representations, which may require architecture-specific context > in the future. > > Signed-off-by: Muhammad Usama Anjum Reviewed-by: Ryan Roberts > --- > arch/arm64/include/asm/pgtable.h | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h > index 4768ec59de555..ce6580ab63128 100644 > --- a/arch/arm64/include/asm/pgtable.h > +++ b/arch/arm64/include/asm/pgtable.h > @@ -360,7 +360,7 @@ static inline pte_t pte_clear_uffd(pte_t pte) > > static inline void __set_pte_nosync(hw_pte_t *ptep, pte_t pte) > { > - WRITE_ONCE(*ptep, pte); > + WRITE_ONCE(hw_pte_val(*ptep), pte_val(pte)); > } > > static inline void __set_pte_complete(pte_t pte) > @@ -381,7 +381,7 @@ static inline void __set_pte(hw_pte_t *ptep, pte_t pte) > > static inline pte_t __ptep_get(hw_pte_t *ptep) > { > - return READ_ONCE(*ptep); > + return __pte(READ_ONCE(hw_pte_val(*ptep))); > } > > extern void __sync_icache_dcache(pte_t pteval); >