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From: Yeoreum Yun <yeoreum.yun@arm.com>
To: Russell King <linux@armlinux.org.uk>,
	 Huacai Chen <chenhuacai@kernel.org>,
	WANG Xuerui <kernel@xen0n.name>,
	 Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
	 Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,  Arnd Bergmann <arnd@arndb.de>,
	Andrew Morton <akpm@linux-foundation.org>,
	 Kairui Song <kasong@tencent.com>, Qi Zheng <qi.zheng@linux.dev>,
	 Shakeel Butt <shakeel.butt@linux.dev>,
	Barry Song <baohua@kernel.org>,
	 Axel Rasmussen <axelrasmussen@google.com>,
	Yuanchu Xie <yuanchu@google.com>,  Wei Xu <weixugc@google.com>,
	Johannes Weiner <hannes@cmpxchg.org>,
	 David Hildenbrand <david@kernel.org>,
	Michal Hocko <mhocko@kernel.org>,
	 Lorenzo Stoakes <ljs@kernel.org>,
	Tianrui Zhao <zhaotianrui@loongson.cn>,
	 Bibo Mao <maobibo@loongson.cn>, Anup Patel <anup@brainfault.org>,
	 Atish Patra <atish.patra@linux.dev>,
	Paul Walmsley <pjw@kernel.org>,
	 Palmer Dabbelt <palmer@dabbelt.com>,
	Albert Ou <aou@eecs.berkeley.edu>,
	 Alexandre Ghiti <alex@ghiti.fr>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	 Andy Lutomirski <luto@kernel.org>,
	Peter Zijlstra <peterz@infradead.org>,
	 Thomas Gleixner <tglx@kernel.org>,
	Ingo Molnar <mingo@redhat.com>,  Borislav Petkov <bp@alien8.de>,
	x86@kernel.org,  "H. Peter Anvin" <hpa@zytor.com>,
	"Liam R. Howlett" <liam@infradead.org>,
	 Vlastimil Babka <vbabka@kernel.org>,
	Mike Rapoport <rppt@kernel.org>,
	 Suren Baghdasaryan <surenb@google.com>,
	Michal Hocko <mhocko@suse.com>,  Jonas Bonn <jonas@southpole.se>,
	 Stefan Kristiansson <stefan.kristiansson@saunalahti.fi>,
	 Stafford Horne <shorne@gmail.com>
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
Subject: [PATCH RFC v3 01/21] ARM: mm: make nommu pgd_t a scalar
Date: Wed, 02 Sep 2026 12:56:03 +0100	[thread overview]
Message-ID: <20260902-dummy_ptxp3-v3-1-5d8f5b17c25c@arm.com> (raw)
In-Reply-To: <20260902-dummy_ptxp3-v3-0-5d8f5b17c25c@arm.com>

From: "David Hildenbrand (Arm)" <david@kernel.org>

As pgd_t is returned  from a function, like pgdp_get(). pgd_t shouldn't be
an array.

There is no need to match the actual arm page tables, because with nommu
there are no page tables. It's all just in place to make the compiler
happy. Making it a scalar will make the compiler happy.

So let's just use an u32.

Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
---
 arch/arm/include/asm/page-nommu.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch/arm/include/asm/page-nommu.h b/arch/arm/include/asm/page-nommu.h
index e74415c959be..88659b38e236 100644
--- a/arch/arm/include/asm/page-nommu.h
+++ b/arch/arm/include/asm/page-nommu.h
@@ -18,12 +18,12 @@
  */
 typedef unsigned long pte_t;
 typedef unsigned long pmd_t;
-typedef unsigned long pgd_t[2];
+typedef unsigned long pgd_t;
 typedef unsigned long pgprot_t;
 
 #define pte_val(x)      (x)
 #define pmd_val(x)      (x)
-#define pgd_val(x)	((x)[0])
+#define pgd_val(x)      (x)
 #define pgprot_val(x)   (x)
 
 #define __pte(x)        (x)

-- 
2.43.0


  reply	other threads:[~2026-09-02 11:56 UTC|newest]

Thread overview: 26+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-09-02 11:56 [PATCH RFC v3 00/21] mm: change behavior of pXdp_get()/pXd_page() in compile-time folded pgtable Yeoreum Yun
2026-09-02 11:56 ` Yeoreum Yun [this message]
2026-09-02 11:56 ` [PATCH RFC v3 02/21] ARM: mm: make 2-level pgd_t a scalar Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 03/21] ARM: mm: remove custom pgdp_get() Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 04/21] LoongArch: mm: define pud_leaf() only when PUD exists Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 05/21] MIPS: " Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 06/21] mm/pgtable: define (pgd|p4d|pud)_leaf() for folded page tables Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 07/21] mm/pgtable: define (pgd|p4d|pud)_offset_lockless() " Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 08/21] mm: vmscan: remove stack copy address of pud/pmd pass in walk_pud/pmd_range() Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 09/21] loongarch: kvm: remove stack copy address of pXd in pXd_offset() Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 10/21] riscv: " Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 11/21] riscv: mm: use proper set_pXd() for generic compile-time folded patable in vmalloc_fault() Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 12/21] mm/pgtable: redefine PGTABLE_LEVEL enum with ascend order from PGD Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 13/21] x86: mm: use pgtable_level enum in effective_prot_pXd() Yeoreum Yun
2026-09-02 20:48   ` Dave Hansen
2026-09-02 11:56 ` [PATCH RFC v3 14/21] x86: mm: carve out the generic compile-time folded pgtable case in effective_prot() Yeoreum Yun
2026-09-02 20:46   ` Dave Hansen
2026-09-02 11:56 ` [PATCH RFC v3 15/21] x86: mm: skip collapse_pud_page() when CONFIG_X86_DIRECT_GBPAGES disabled Yeoreum Yun
2026-09-02 15:38   ` Dave Hansen
2026-09-02 16:48     ` Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 16/21] openrisc/pgtable: drop __pmd_offset() Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 17/21] mm/pgtable: optimize pmdp_get() and friends for folded pagetable levels Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 18/21] mm/pgtable: catch abuse of folded dummy pgd_t/p4d_t/pud_t Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 19/21] mm/pgtable: disallow calling (pgd|p4d|pud)_page, pgd_page_vaddr() and (p4d|pud)_pgtable with dummy Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 20/21] mm/pgtable: disallow calling folded set_pgd/set_p4d/set_pud " Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 21/21] Documentation: mm: clarify behaviour of compile-time folded page tables Yeoreum Yun

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