linux-kernel - [PATCH v2] asm-generic: Remove pud

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Message-ID: <c2c9fc69871a7caaa205e237ff73557f19f5e176.1755509286.git.christophe.leroy@csgroup.eu>
Date: Mon, 18 Aug 2025 11:35:29 +0200
From: Christophe Leroy <christophe.leroy@...roup.eu>
To: Arnd Bergmann <arnd@...db.de>,
	linux-arch@...r.kernel.org,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-mm@...ck.org
Cc: Christophe Leroy <christophe.leroy@...roup.eu>,
	linux-arm-kernel@...ts.infradead.org,
	linux-kernel@...r.kernel.org,
	linux-riscv@...ts.infradead.org,
	Catalin Marinas <catalin.marinas@....com>,
	Will Deacon <will@...nel.org>,
	Paul Walmsley <paul.walmsley@...ive.com>,
	Palmer Dabbelt <palmer@...belt.com>,
	Albert Ou <aou@...s.berkeley.edu>,
	Alexandre Ghiti <alex@...ti.fr>,
	Peter Xu <peterx@...hat.com>,
	Oscar Salvador <osalvador@...e.de>,
	Alexandre Ghiti <alexghiti@...osinc.com>
Subject: [PATCH v2] asm-generic: Remove pud_user() from pgtable-nopmd.h

Commit 2c8a81dc0cc5 ("riscv/mm: fix two page table check related
issues") added pud_user() in include/asm-generic/pgtable-nopmd.h

But pud_user() only exists on ARM64 and RISCV and is not expected
by any part of MM.

Add the missing definition in arch/riscv/include/asm/pgtable-32.h
and remove it from asm-generic/pgtable-nopmd.h

A stub pud_user() is also required for ARM64 after
commit ed928a3402d8 ("arm64/mm: fix page table check compile
error for CONFIG_PGTABLE_LEVELS=2")

Signed-off-by: Christophe Leroy <christophe.leroy@...roup.eu>
Reviewed-by: Peter Xu <peterx@...hat.com>
Reviewed-by: Oscar Salvador <osalvador@...e.de>
Acked-by: Alexandre Ghiti <alexghiti@...osinc.com> # riscv
Acked-by: Catalin Marinas <catalin.marinas@....com>
---
Not sure whether this goes via asm-generic or mm as it touches the earth of mm allthough the files are in asm-generic

v2: Change ARM64 pud_user macro to pud_user(pud)
---
 arch/arm64/include/asm/pgtable.h    | 1 +
 arch/riscv/include/asm/pgtable-32.h | 5 +++++
 include/asm-generic/pgtable-nopmd.h | 1 -
 3 files changed, 6 insertions(+), 1 deletion(-)

diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index abd2dee416b3..d812ed1c96b4 100644
--- a/arch/arm64/include/asm/pgtable.h
+++ b/arch/arm64/include/asm/pgtable.h
@@ -955,6 +955,7 @@ static inline pmd_t *pud_pgtable(pud_t pud)
 
 #define pud_valid(pud)		false
 #define pud_page_paddr(pud)	({ BUILD_BUG(); 0; })
+#define pud_user(pud)		false /* Always 0 with folding */
 #define pud_user_exec(pud)	pud_user(pud) /* Always 0 with folding */
 
 /* Match pmd_offset folding in <asm/generic/pgtable-nopmd.h> */
diff --git a/arch/riscv/include/asm/pgtable-32.h b/arch/riscv/include/asm/pgtable-32.h
index 00f3369570a8..37878ef37466 100644
--- a/arch/riscv/include/asm/pgtable-32.h
+++ b/arch/riscv/include/asm/pgtable-32.h
@@ -36,4 +36,9 @@
 static const __maybe_unused int pgtable_l4_enabled;
 static const __maybe_unused int pgtable_l5_enabled;
 
+static inline int pud_user(pud_t pud)
+{
+	return 0;
+}
+
 #endif /* _ASM_RISCV_PGTABLE_32_H */
diff --git a/include/asm-generic/pgtable-nopmd.h b/include/asm-generic/pgtable-nopmd.h
index 8ffd64e7a24c..b01349a312fa 100644
--- a/include/asm-generic/pgtable-nopmd.h
+++ b/include/asm-generic/pgtable-nopmd.h
@@ -30,7 +30,6 @@ typedef struct { pud_t pud; } pmd_t;
 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 void pud_clear(pud_t *pud)	{ }
 #define pmd_ERROR(pmd)				(pud_ERROR((pmd).pud))
-- 
2.49.0