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 06/21] mm/pgtable: define (pgd|p4d|pud)_leaf() for folded page tables
Date: Wed, 02 Sep 2026 12:56:08 +0100 [thread overview]
Message-ID: <20260902-dummy_ptxp3-v3-6-5d8f5b17c25c@arm.com> (raw)
In-Reply-To: <20260902-dummy_ptxp3-v3-0-5d8f5b17c25c@arm.com>
From: "David Hildenbrand (Arm)" <david@kernel.org>
Define (pgd|p4d|pud)_leaf(), hard-coding it to "false". Note
that it's missed to define pud_leaf() before, allowing architectures to
unknowingly overwrite it.
Still use static inline functions (type checking), and while at it, just
use "bool" as a return value.
Signed-off-by: David Hildenbrand (Arm) <david@kernel.org>
---
include/asm-generic/pgtable-nop4d.h | 3 +++
include/asm-generic/pgtable-nopmd.h | 3 ++-
include/asm-generic/pgtable-nopud.h | 3 +++
3 files changed, 8 insertions(+), 1 deletion(-)
diff --git a/include/asm-generic/pgtable-nop4d.h b/include/asm-generic/pgtable-nop4d.h
index 1cf739ee38aa..c6a5a43899b5 100644
--- a/include/asm-generic/pgtable-nop4d.h
+++ b/include/asm-generic/pgtable-nop4d.h
@@ -22,6 +22,9 @@ static inline int pgd_none(pgd_t pgd) { return 0; }
static inline int pgd_bad(pgd_t pgd) { return 0; }
static inline int pgd_present(pgd_t pgd) { return 1; }
static inline void pgd_clear(pgd_t *pgd) { }
+static inline bool pgd_leaf(pgd_t pgd) { return false; }
+#define pgd_leaf pgd_leaf
+#define p4d_ERROR(p4d) (pgd_ERROR((p4d).pgd))
#define pgd_populate(mm, pgd, p4d) do { } while (0)
#define pgd_populate_safe(mm, pgd, p4d) do { } while (0)
diff --git a/include/asm-generic/pgtable-nopmd.h b/include/asm-generic/pgtable-nopmd.h
index ff4235cf84d7..4e5aaf253b6a 100644
--- a/include/asm-generic/pgtable-nopmd.h
+++ b/include/asm-generic/pgtable-nopmd.h
@@ -31,7 +31,8 @@ static inline int pud_none(pud_t pud) { return 0; }
static inline int pud_bad(pud_t pud) { return 0; }
static inline int pud_present(pud_t pud) { return 1; }
static inline int pud_user(pud_t pud) { return 0; }
-static inline int pud_leaf(pud_t pud) { return 0; }
+static inline bool pud_leaf(pud_t pud) { return false; }
+#define pud_leaf pud_leaf
static inline void pud_clear(pud_t *pud) { }
#define pud_populate(mm, pmd, pte) do { } while (0)
diff --git a/include/asm-generic/pgtable-nopud.h b/include/asm-generic/pgtable-nopud.h
index eedee8e3ad68..6c9bca78047c 100644
--- a/include/asm-generic/pgtable-nopud.h
+++ b/include/asm-generic/pgtable-nopud.h
@@ -29,6 +29,9 @@ static inline int p4d_none(p4d_t p4d) { return 0; }
static inline int p4d_bad(p4d_t p4d) { return 0; }
static inline int p4d_present(p4d_t p4d) { return 1; }
static inline void p4d_clear(p4d_t *p4d) { }
+static inline bool p4d_leaf(p4d_t p4d) { return false; }
+#define p4d_leaf p4d_leaf
+#define pud_ERROR(pud) (p4d_ERROR((pud).p4d))
#define p4d_populate(mm, p4d, pud) do { } while (0)
#define p4d_populate_safe(mm, p4d, pud) do { } while (0)
--
2.43.0
next prev parent reply other threads:[~2026-09-02 11:57 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 ` [PATCH RFC v3 01/21] ARM: mm: make nommu pgd_t a scalar Yeoreum Yun
2026-09-02 11:56 ` [PATCH RFC v3 02/21] ARM: mm: make 2-level " 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 ` Yeoreum Yun [this message]
2026-09-02 11:56 ` [PATCH RFC v3 07/21] mm/pgtable: define (pgd|p4d|pud)_offset_lockless() for folded page tables 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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