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From: Kevin Brodsky <kevin.brodsky@arm.com>
To: linux-mm@kvack.org
Cc: Kevin Brodsky <kevin.brodsky@arm.com>,
	 Andrew Morton <akpm@linux-foundation.org>,
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	 linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org
Subject: [PATCH 18/22] arm64: mm: drop explicit mm_is_efi() check in contpte
Date: Tue, 14 Jul 2026 15:04:07 +0100	[thread overview]
Message-ID: <20260714-remove_pgtable_cdtor-v1-18-44be8a7685d7@arm.com> (raw)
In-Reply-To: <20260714-remove_pgtable_cdtor-v1-0-44be8a7685d7@arm.com>

efi_mm is now marked as a kernel mm, like init_mm. mm_is_kernel()
therefore gives the right answer for efi_mm and mm_is_user() is now
equivalent to !mm_is_kernel().

Remove mm_is_user() and directly use mm_is_kernel() instead.

Assisted-by: Codex:GPT-5.5
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
---
 arch/arm64/mm/contpte.c | 26 +++++++++-----------------
 1 file changed, 9 insertions(+), 17 deletions(-)

diff --git a/arch/arm64/mm/contpte.c b/arch/arm64/mm/contpte.c
index ad5c04cf66ff..e21e279101ca 100644
--- a/arch/arm64/mm/contpte.c
+++ b/arch/arm64/mm/contpte.c
@@ -4,23 +4,9 @@
  */
 
 #include <linux/mm.h>
-#include <linux/efi.h>
 #include <linux/export.h>
 #include <asm/tlbflush.h>
 
-static inline bool mm_is_user(struct mm_struct *mm)
-{
-	/*
-	 * Don't attempt to apply the contig bit to kernel mappings, because
-	 * dynamically adding/removing the contig bit can cause page faults.
-	 * These racing faults are ok for user space, since they get serialized
-	 * on the PTL. But kernel mappings can't tolerate faults.
-	 */
-	if (unlikely(mm_is_efi(mm)))
-		return false;
-	return !mm_is_kernel(mm);
-}
-
 static inline pte_t *contpte_align_down(pte_t *ptep)
 {
 	return PTR_ALIGN_DOWN(ptep, sizeof(*ptep) * CONT_PTES);
@@ -263,7 +249,13 @@ void __contpte_try_fold(struct mm_struct *mm, unsigned long addr,
 
 	int i;
 
-	if (!mm_is_user(mm))
+	/*
+	 * Don't attempt to apply the contig bit to kernel mappings, because
+	 * dynamically adding/removing the contig bit can cause page faults.
+	 * These racing faults are ok for user space, since they get serialized
+	 * on the PTL. But kernel mappings can't tolerate faults.
+	 */
+	if (mm_is_kernel(mm))
 		return;
 
 	page = pte_page(pte);
@@ -302,7 +294,7 @@ void __contpte_try_unfold(struct mm_struct *mm, unsigned long addr,
 	 * We have already checked that the ptes are contiguous in
 	 * contpte_try_unfold(), so just check that the mm is user space.
 	 */
-	if (!mm_is_user(mm))
+	if (mm_is_kernel(mm))
 		return;
 
 	pte = pte_mknoncont(pte);
@@ -465,7 +457,7 @@ void contpte_set_ptes(struct mm_struct *mm, unsigned long addr,
 	 */
 	VM_WARN_ON(nr == 1);
 
-	if (!mm_is_user(mm))
+	if (mm_is_kernel(mm))
 		return __set_ptes(mm, addr, ptep, pte, nr);
 
 	end = addr + (nr << PAGE_SHIFT);

-- 
2.51.2


  parent reply	other threads:[~2026-07-14 14:07 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-07-14 14:03 [PATCH 00/22] Simplify special kernel page table handling Kevin Brodsky
2026-07-14 14:03 ` [PATCH 01/22] mm: drop unused __mm_flags_set_mask_bits_word() Kevin Brodsky
2026-07-14 14:03 ` [PATCH 02/22] mm: move mm_flags helpers to mm_types.h Kevin Brodsky
2026-07-14 14:03 ` [PATCH 03/22] mm: introduce MMF_KERNEL flag and set it for init_mm Kevin Brodsky
2026-07-14 14:47   ` Dave Hansen
2026-07-14 15:04     ` Lorenzo Stoakes (ARM)
2026-07-14 14:03 ` [PATCH 04/22] mm: use mm_is_kernel() in generic page table code Kevin Brodsky
2026-07-14 14:03 ` [PATCH 05/22] arm64: mm: use mm_is_kernel() for kernel mm checks Kevin Brodsky
2026-07-14 14:03 ` [PATCH 06/22] loongarch: mm: use mm_is_kernel() in switch_mm_irqs_off() Kevin Brodsky
2026-07-14 14:03 ` [PATCH 07/22] parisc: mm: use mm_is_kernel() for kernel mm checks Kevin Brodsky
2026-07-14 14:03 ` [PATCH 08/22] powerpc: " Kevin Brodsky
2026-07-14 14:03 ` [PATCH 09/22] s390: " Kevin Brodsky
2026-07-14 14:03 ` [PATCH 10/22] sparc: " Kevin Brodsky
2026-07-14 14:04 ` [PATCH 11/22] um: mm: use mm_is_kernel() in TLB sync Kevin Brodsky
2026-07-14 14:04 ` [PATCH 12/22] x86/mm: use mm_is_kernel() for kernel mm checks Kevin Brodsky
2026-07-14 15:09   ` Dave Hansen
2026-07-14 14:04 ` [PATCH 13/22] mm: account page table pages when allocated Kevin Brodsky
2026-07-14 14:04 ` [PATCH 14/22] mm: set page table page type " Kevin Brodsky
2026-07-14 15:16   ` Vishal Moola
2026-07-14 14:04 ` [PATCH 15/22] mm: only initialise pt_share_count for user pgtables Kevin Brodsky
2026-07-14 14:04 ` [PATCH 16/22] efi: mark efi_mm as a kernel mm Kevin Brodsky
2026-07-14 14:04 ` [PATCH 17/22] mm: pagewalk: drop redundant address check for kernel mm walks Kevin Brodsky
2026-07-14 14:04 ` Kevin Brodsky [this message]
2026-07-14 14:04 ` [PATCH 19/22] x86/tboot: mark tboot_mm as a kernel mm Kevin Brodsky
2026-07-14 15:19   ` Dave Hansen
2026-07-14 14:04 ` [PATCH 20/22] arm64: mm: drop ctor/dtor calls for kernel page tables Kevin Brodsky
2026-07-14 14:04 ` [PATCH 21/22] arm: mm: drop ctor call " Kevin Brodsky
2026-07-14 14:04 ` [PATCH 22/22] riscv: mm: drop ctor/dtor calls " Kevin Brodsky

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