From: Ryan Roberts <ryan.roberts@arm.com>
To: Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>, Ard Biesheuvel <ardb@kernel.org>,
Marc Zyngier <maz@kernel.org>, James Morse <james.morse@arm.com>,
Andrey Ryabinin <ryabinin.a.a@gmail.com>,
Andrew Morton <akpm@linux-foundation.org>,
Matthew Wilcox <willy@infradead.org>,
Mark Rutland <mark.rutland@arm.com>,
David Hildenbrand <david@redhat.com>,
Kefeng Wang <wangkefeng.wang@huawei.com>,
John Hubbard <jhubbard@nvidia.com>, Zi Yan <ziy@nvidia.com>,
Barry Song <21cnbao@gmail.com>,
Alistair Popple <apopple@nvidia.com>,
Yang Shi <shy828301@gmail.com>,
Nicholas Piggin <npiggin@gmail.com>,
Christophe Leroy <christophe.leroy@csgroup.eu>,
"Aneesh Kumar K.V" <aneesh.kumar@kernel.org>,
"Naveen N. Rao" <naveen.n.rao@linux.ibm.com>,
Thomas Gleixner <tglx@linutronix.de>,
Ingo Molnar <mingo@redhat.com>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H. Peter Anvin" <hpa@zytor.com>
Cc: Ryan Roberts <ryan.roberts@arm.com>,
linux-arm-kernel@lists.infradead.org, x86@kernel.org,
linuxppc-dev@lists.ozlabs.org, linux-mm@kvack.org,
linux-kernel@vger.kernel.org
Subject: [PATCH v5 01/25] mm: Clarify the spec for set_ptes()
Date: Fri, 2 Feb 2024 08:07:32 +0000 [thread overview]
Message-ID: <20240202080756.1453939-2-ryan.roberts@arm.com> (raw)
In-Reply-To: <20240202080756.1453939-1-ryan.roberts@arm.com>
set_ptes() spec implies that it can only be used to set a present pte
because it interprets the PFN field to increment it. However,
set_pte_at() has been implemented on top of set_ptes() since set_ptes()
was introduced, and set_pte_at() allows setting a pte to a not-present
state. So clarify the spec to state that when nr==1, new state of pte
may be present or not present. When nr>1, new state of all ptes must be
present.
While we are at it, tighten the spec to set requirements around the
initial state of ptes; when nr==1 it may be either present or
not-present. But when nr>1 all ptes must initially be not-present. All
set_ptes() callsites already conform to this requirement. Stating it
explicitly is useful because it allows for a simplification to the
upcoming arm64 contpte implementation.
Signed-off-by: Ryan Roberts <ryan.roberts@arm.com>
---
include/linux/pgtable.h | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/include/linux/pgtable.h b/include/linux/pgtable.h
index f0feae7f89fb..5e7eaf8f2b97 100644
--- a/include/linux/pgtable.h
+++ b/include/linux/pgtable.h
@@ -229,6 +229,10 @@ static inline pte_t pte_next_pfn(pte_t pte)
* @pte: Page table entry for the first page.
* @nr: Number of pages to map.
*
+ * When nr==1, initial state of pte may be present or not present, and new state
+ * may be present or not present. When nr>1, initial state of all ptes must be
+ * not present, and new state must be present.
+ *
* May be overridden by the architecture, or the architecture can define
* set_pte() and PFN_PTE_SHIFT.
*
--
2.25.1
next prev parent reply other threads:[~2024-02-02 8:08 UTC|newest]
Thread overview: 80+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-02 8:07 [PATCH v5 00/25] Transparent Contiguous PTEs for User Mappings Ryan Roberts
2024-02-02 8:07 ` Ryan Roberts [this message]
2024-02-12 12:03 ` [PATCH v5 01/25] mm: Clarify the spec for set_ptes() David Hildenbrand
2024-02-02 8:07 ` [PATCH v5 02/25] mm: thp: Batch-collapse PMD with set_ptes() Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 03/25] mm: Make pte_next_pfn() a wrapper around pte_advance_pfn() Ryan Roberts
2024-02-12 12:14 ` David Hildenbrand
2024-02-12 14:10 ` Ryan Roberts
2024-02-12 14:29 ` David Hildenbrand
2024-02-12 21:34 ` Ryan Roberts
2024-02-13 9:54 ` David Hildenbrand
2024-02-02 8:07 ` [PATCH v5 04/25] arm/mm: Convert pte_next_pfn() to pte_advance_pfn() Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 05/25] arm64/mm: " Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 06/25] powerpc/mm: " Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 07/25] x86/mm: " Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 08/25] mm: Remove pte_next_pfn() and replace with pte_advance_pfn() Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 09/25] arm64/mm: set_pte(): New layer to manage contig bit Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 10/25] arm64/mm: set_ptes()/set_pte_at(): " Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 11/25] arm64/mm: pte_clear(): " Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 12/25] arm64/mm: ptep_get_and_clear(): " Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 13/25] arm64/mm: ptep_test_and_clear_young(): " Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 14/25] arm64/mm: ptep_clear_flush_young(): " Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 15/25] arm64/mm: ptep_set_wrprotect(): " Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 16/25] arm64/mm: ptep_set_access_flags(): " Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 17/25] arm64/mm: ptep_get(): " Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 18/25] arm64/mm: Split __flush_tlb_range() to elide trailing DSB Ryan Roberts
2024-02-12 12:44 ` David Hildenbrand
2024-02-12 13:05 ` Ryan Roberts
2024-02-12 13:15 ` David Hildenbrand
2024-02-12 13:27 ` Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 19/25] arm64/mm: Wire up PTE_CONT for user mappings Ryan Roberts
2024-02-12 12:00 ` Mark Rutland
2024-02-12 12:59 ` Ryan Roberts
2024-02-12 13:54 ` David Hildenbrand
2024-02-12 14:45 ` Ryan Roberts
2024-02-12 15:26 ` David Hildenbrand
2024-02-12 15:34 ` Ryan Roberts
2024-02-12 16:24 ` David Hildenbrand
2024-02-13 15:29 ` Ryan Roberts
2024-02-12 15:30 ` Ryan Roberts
2024-02-12 20:38 ` Ryan Roberts
2024-02-13 10:01 ` David Hildenbrand
2024-02-13 12:06 ` Ryan Roberts
2024-02-13 12:19 ` David Hildenbrand
2024-02-13 13:06 ` Ryan Roberts
2024-02-13 13:13 ` David Hildenbrand
2024-02-13 13:20 ` Ryan Roberts
2024-02-13 13:22 ` David Hildenbrand
2024-02-13 13:24 ` Ryan Roberts
2024-02-13 13:33 ` Ard Biesheuvel
2024-02-13 13:45 ` David Hildenbrand
2024-02-13 14:02 ` Ryan Roberts
2024-02-13 14:05 ` David Hildenbrand
2024-02-13 14:08 ` Ard Biesheuvel
2024-02-13 14:21 ` Ryan Roberts
2024-02-13 12:02 ` Mark Rutland
2024-02-13 13:03 ` Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 20/25] arm64/mm: Implement new wrprotect_ptes() batch API Ryan Roberts
2024-02-13 16:31 ` Mark Rutland
2024-02-13 16:36 ` Ryan Roberts
2024-02-02 8:07 ` [PATCH v5 21/25] arm64/mm: Implement new [get_and_]clear_full_ptes() batch APIs Ryan Roberts
2024-02-13 16:43 ` Mark Rutland
2024-02-13 16:48 ` Ryan Roberts
2024-02-13 16:53 ` Mark Rutland
2024-02-02 8:07 ` [PATCH v5 22/25] mm: Add pte_batch_hint() to reduce scanning in folio_pte_batch() Ryan Roberts
2024-02-12 13:43 ` David Hildenbrand
2024-02-12 15:00 ` Ryan Roberts
2024-02-12 15:47 ` Ryan Roberts
2024-02-12 16:27 ` David Hildenbrand
2024-02-02 8:07 ` [PATCH v5 23/25] arm64/mm: Implement pte_batch_hint() Ryan Roberts
2024-02-12 13:46 ` David Hildenbrand
2024-02-13 16:54 ` Mark Rutland
2024-02-02 8:07 ` [PATCH v5 24/25] arm64/mm: __always_inline to improve fork() perf Ryan Roberts
2024-02-13 16:55 ` Mark Rutland
2024-02-02 8:07 ` [PATCH v5 25/25] arm64/mm: Automatically fold contpte mappings Ryan Roberts
2024-02-13 17:44 ` Mark Rutland
2024-02-13 18:05 ` Ryan Roberts
2024-02-08 17:34 ` [PATCH v5 00/25] Transparent Contiguous PTEs for User Mappings Mark Rutland
2024-02-09 8:54 ` Ryan Roberts
2024-02-09 22:16 ` David Hildenbrand
2024-02-09 23:52 ` Ryan Roberts
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