From: Muhammad Usama Anjum <usama.anjum@arm.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>,
Mark Rutland <mark.rutland@arm.com>,
Ard Biesheuvel <ardb@kernel.org>,
Ilias Apalodimas <ilias.apalodimas@linaro.org>,
Andrey Ryabinin <ryabinin.a.a@gmail.com>,
Alexander Potapenko <glider@google.com>,
Andrey Konovalov <andreyknvl@gmail.com>,
Dmitry Vyukov <dvyukov@google.com>,
Vincenzo Frascino <vincenzo.frascino@arm.com>,
Andrew Morton <akpm@linux-foundation.org>,
David Hildenbrand <david@kernel.org>,
Lorenzo Stoakes <ljs@kernel.org>,
"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>
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,
Muhammad Usama Anjum <usama.anjum@arm.com>
Subject: [PATCH 3/6] arm64: convert between HW PTEs and SW PTE values
Date: Mon, 14 Sep 2026 14:51:33 +0100 [thread overview]
Message-ID: <20260914-pte0_arm-v1-3-bb53b663e396@arm.com> (raw)
In-Reply-To: <20260914-pte0_arm-v1-0-bb53b663e396@arm.com>
__ptep_get() returns a SW PTE value, and __set_pte_nosync() accepts one.
When HW PTEs use a distinct hw_pte_t, directly reading or writing *ptep
as a SW PTE value no longer satisfies those interfaces.
Use __pte_from_hw after READ_ONCE() to obtain a SW PTE value and add
__hw_pte before WRITE_ONCE() to form an HW PTE.
Define __hw_pte for both the wrapper and alias configurations so the
same accessor code works in either case.
Signed-off-by: Muhammad Usama Anjum <usama.anjum@arm.com>
---
arch/arm64/include/asm/pgtable.h | 4 ++--
include/linux/pgtable_types.h | 2 ++
2 files changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/arm64/include/asm/pgtable.h b/arch/arm64/include/asm/pgtable.h
index 4768ec59de555..67c4a6179e154 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(*ptep, __hw_pte(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_from_hw(READ_ONCE(*ptep));
}
extern void __sync_icache_dcache(pte_t pteval);
diff --git a/include/linux/pgtable_types.h b/include/linux/pgtable_types.h
index ee4eace5c3e1c..b5862a16aa497 100644
--- a/include/linux/pgtable_types.h
+++ b/include/linux/pgtable_types.h
@@ -9,11 +9,13 @@
#ifdef CONFIG_ARCH_HAS_HW_PTE_T
typedef struct __hw_pte_t { pte_t __pte; } hw_pte_t;
#define __pte_from_hw(pte) ((pte).__pte)
+#define __hw_pte(pte) ((hw_pte_t) { (pte) })
#define hw_pte_val(x) pte_val((x).__pte)
#else
#define hw_pte_t pte_t
#define __pte_from_hw(pte) (pte)
+#define __hw_pte(pte) (pte)
#define hw_pte_val(x) pte_val(x)
#endif
--
2.47.3
next prev parent reply other threads:[~2026-09-14 13:52 UTC|newest]
Thread overview: 11+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-09-14 13:51 [PATCH 0/6] arm64: distinguish HW PTE pointers from SW PTE value pointers Muhammad Usama Anjum
2026-09-14 13:51 ` [PATCH 1/6] arm64: use hw_pte_t for HW PTE pointers Muhammad Usama Anjum
2026-09-14 13:51 ` [PATCH 2/6] arm64: use hw_pte_val for HW PTE atomics Muhammad Usama Anjum
2026-09-18 15:55 ` Ryan Roberts
2026-09-14 13:51 ` Muhammad Usama Anjum [this message]
2026-09-18 15:56 ` [PATCH 3/6] arm64: convert between HW PTEs and SW PTE values Ryan Roberts
2026-09-14 13:51 ` [PATCH 4/6] arm64: use hw_pte_t for fixmap HW PTEs Muhammad Usama Anjum
2026-09-18 16:03 ` Ryan Roberts
2026-09-18 20:00 ` David Hildenbrand (Arm)
2026-09-14 13:51 ` [PATCH 5/6] arm64: use HW PTE accessors in early map_range() Muhammad Usama Anjum
2026-09-14 13:51 ` [PATCH 6/6] arm64: enable a distinct type for HW PTEs Muhammad Usama Anjum
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