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 A4164486620; Mon, 21 Sep 2026 10:56:44 +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=1789988206; cv=none; b=ptg0ONNrVk0rf7pB+5pDQ0ZMITji6NZCJuPnUzNU76/cfI7JE/h8tN6CRYyga9KpRKU3V/Nzp80nR2xAwlN9crP2wY9N7EQ2HMLiMDmnicW7xu83c4uF8sPXMApexlIttMH9gGPjvF6hNQPpKeY72NM8tLQRW3Nel2O+/IH5e20= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789988206; c=relaxed/simple; bh=MWIk55sq3Xl5IhFPSCZgQqnLya5ldzX0H6ZlzYM7l/s=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=IQ+Jo558uL3i0mTrMfhfQITLE/Sg9FGKqelS93I8AKfcKaGZ+GUhU9cWlnfyt+qJxdp9CfQhZqmI3WKY1f8whQnnAr0ZDvYmAgdccSnT62FsD/azTEARg2TNeBELRP0Gg7ERFJ9/oDYGBJ0900f/GLtPZEbZ3DzKfF4icYJjd24= 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=jmExSGw2; 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="jmExSGw2" 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 8EC071D70; Mon, 21 Sep 2026 03:56:40 -0700 (PDT) Received: from e129823.arm.com (e129823.arm.com [10.2.213.3]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id EC3F63F86C; Mon, 21 Sep 2026 03:56:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1789988204; bh=MWIk55sq3Xl5IhFPSCZgQqnLya5ldzX0H6ZlzYM7l/s=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=jmExSGw2LCoPoWhLv7wl3mcvZhvvMu/EFGtYz/YIjBdIYLmZ8xYhg+Bt8Lk13zyPM uN6j9Bi3PcRRphGGPrmscaNUQ1hMTG6ePRq5Ad874ubG9TqkzhXg+MtwYO6s/uX21/ w+FObAyJbBmnpGp1xy4Af27ePeH4jFFQJWayxXdA= From: Yeoreum Yun Date: Mon, 21 Sep 2026 11:55:24 +0100 Subject: [PATCH 02/21] ARM: mm: make 2-level pgd_t a scalar Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260921-dummy_ptxp3-v1-2-cd40cf68242e@arm.com> References: <20260921-dummy_ptxp3-v1-0-cd40cf68242e@arm.com> In-Reply-To: <20260921-dummy_ptxp3-v1-0-cd40cf68242e@arm.com> To: Russell King , Huacai Chen , WANG Xuerui , Thomas Bogendoerfer , Catalin Marinas , Will Deacon , Arnd Bergmann , Andrew Morton , Kairui Song , Qi Zheng , Shakeel Butt , Barry Song , Axel Rasmussen , Yuanchu Xie , Wei Xu , Johannes Weiner , David Hildenbrand , Michal Hocko , Lorenzo Stoakes , Tianrui Zhao , Bibo Mao , Anup Patel , Atish Patra , Paul Walmsley , Palmer Dabbelt , Albert Ou , Alexandre Ghiti , Dave Hansen , Andy Lutomirski , Peter Zijlstra , Thomas Gleixner , Ingo Molnar , Borislav Petkov , x86@kernel.org, "H. Peter Anvin" , "Liam R. Howlett" , Vlastimil Babka , Mike Rapoport , Suren Baghdasaryan , Michal Hocko , Jonas Bonn , Stefan Kristiansson , Stafford Horne Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linux-mips@vger.kernel.org, linux-arch@vger.kernel.org, linux-mm@kvack.org, kvm@vger.kernel.org, kvm-riscv@lists.infradead.org, linux-riscv@lists.infradead.org, linux-openrisc@vger.kernel.org X-Mailer: b4 0.13.0 X-Developer-Signature: v=1; a=openpgp-sha256; l=2019; i=yeoreum.yun@arm.com; h=from:subject:message-id; bh=4Z0osGAP3S0civxPu6dKKFX1qsd70Ol0fauRungSauY=; b=owEB7QES/pANAwAKAW3Vw9FaxTEzAcsmYgBqsQ1LPMd3bY5l97IcQgb37uybVOO0YHrmaWze2 pZkKGx8ILSJAbMEAAEKAB0WIQQtg+CS3QUzuFh1pJ1t1cPRWsUxMwUCarENSwAKCRBt1cPRWsUx Mwi2C/95zvtyR94wqriOwlZeIlIVdVW5IF05ARsQWsZciGmadMujO3xVKbNNHmP7n4X6txHc9Bt 1yPnW09kbOfe7xYWAPC4nw7e/Hz3E9vAZKgyIA+coj/w3E4SPS7GTyJ73zHuaoDvwAQEISXVRPW Pc2D0qopExouM3mWXINlfYnSOrYBHF4n6Li9Svio9m9EvcuV7NFR6d7+63k62CpNiUtK+tbIl0T RjaODkF1exxt6WziJl3rlm/T5QqRmjtA7pQyQ0EsNsVW91e7QgyT12RizaKDjYq/R7+ybfAinCt vRf66DRuwomc5tDPxoUIYUjiLa+sJLJr8TY0hv+mQ1Q4/4hMCPHnlYAGZShYe9PiTNmx6Mebzaw Uf8pO5f6ifwoPDZYfnwsLX3DPUMkDWnDejDdUiskVvMfbwCSuyIZeeDy3cP8ZxoJbVzyOdfp5Ok 0ZzHyHaELLDw/lpY50IvDiCohQ0OsFlKpDv5F9Z6evbkrsXVyMpScSsKxaQVtexaZTtl0= X-Developer-Key: i=yeoreum.yun@arm.com; a=openpgp; fpr=2D83E092DD0533B85875A49D6DD5C3D15AC53133 From: "David Hildenbrand (Arm)" As pgd_t is returned from a function like pgdp_get(), pgd_t shouldn't be an array. So, just use an u64, and extract the right 32bit value in pgd_val(). Leave the STRICT_MM_TYPECHECKS case alone for now. As an alternative, the STRICT_MM_TYPECHECKS approach could be used here as well, but using an u64 looks conceptually cleaner, even though pgd_val() gets a bit more involved. Signed-off-by: David Hildenbrand (Arm) --- arch/arm/include/asm/pgtable-2level-types.h | 20 +++++++++++++++++--- 1 file changed, 17 insertions(+), 3 deletions(-) diff --git a/arch/arm/include/asm/pgtable-2level-types.h b/arch/arm/include/asm/pgtable-2level-types.h index 650e793f41429..805044ea315b7 100644 --- a/arch/arm/include/asm/pgtable-2level-types.h +++ b/arch/arm/include/asm/pgtable-2level-types.h @@ -25,7 +25,7 @@ typedef struct { pteval_t pgprot; } pgprot_t; #define pte_val(x) ((x).pte) #define pmd_val(x) ((x).pmd) -#define pgd_val(x) ((x).pgd[0]) +#define pgd_val(x) ((x).pgd[0]) #define pgprot_val(x) ((x).pgprot) #define __pte(x) ((pte_t) { (x) } ) @@ -36,14 +36,28 @@ typedef struct { pteval_t pgprot; } pgprot_t; /* * .. while these make it easier on the compiler */ +typedef u64 pgdval_t; + 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; #define pte_val(x) (x) #define pmd_val(x) (x) -#define pgd_val(x) ((x)[0]) + +static inline pmdval_t pgd_val(pgd_t pgd) +{ + /* + * A PGD entry actually corresponds to two PMD entries in the PMD table. + * Both PMD entries point to PTE tables residing in the same physical page, + * but at different offsets. See include/asm/pgtable-2level.h for details. + * + * Historically, pgd_val() has returned the lower of the two PMD entries. + */ + return (*(pmdval_t (*)[2])&pgd)[0]; +} + #define pgprot_val(x) (x) #define __pte(x) (x) -- 2.43.0