Generic Linux architectural discussions
 help / color / mirror / Atom feed
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>,
	 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>,
	Pasha Tatashin <pasha.tatashin@soleen.com>,
	 Russell King <linux@armlinux.org.uk>,
	 Catalin Marinas <catalin.marinas@arm.com>,
	Will Deacon <will@kernel.org>,
	 Ryan Roberts <ryan.roberts@arm.com>,
	linux-arm-kernel@lists.infradead.org,
	 Huacai Chen <chenhuacai@kernel.org>,
	loongarch@lists.linux.dev,
	 "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>,
	 Helge Deller <deller@gmx.de>,
	linux-parisc@vger.kernel.org,
	 Madhavan Srinivasan <maddy@linux.ibm.com>,
	 Michael Ellerman <mpe@ellerman.id.au>,
	linuxppc-dev@lists.ozlabs.org,  Paul Walmsley <pjw@kernel.org>,
	Palmer Dabbelt <palmer@dabbelt.com>,
	 Albert Ou <aou@eecs.berkeley.edu>,
	linux-riscv@lists.infradead.org,
	 Heiko Carstens <hca@linux.ibm.com>,
	Vasily Gorbik <gor@linux.ibm.com>,
	 Alexander Gordeev <agordeev@linux.ibm.com>,
	 Gerald Schaefer <gerald.schaefer@linux.ibm.com>,
	linux-s390@vger.kernel.org,
	 "David S. Miller" <davem@davemloft.net>,
	 Andreas Larsson <andreas@gaisler.com>,
	sparclinux@vger.kernel.org,  Richard Weinberger <richard@nod.at>,
	 Anton Ivanov <anton.ivanov@cambridgegreys.com>,
	 Johannes Berg <johannes@sipsolutions.net>,
	linux-um@lists.infradead.org,  Thomas Gleixner <tglx@kernel.org>,
	Ingo Molnar <mingo@redhat.com>,  Borislav Petkov <bp@alien8.de>,
	Dave Hansen <dave.hansen@linux.intel.com>,
	 "H. Peter Anvin" <hpa@zytor.com>,
	Andy Lutomirski <luto@kernel.org>,
	 Peter Zijlstra <peterz@infradead.org>,
	Ning Sun <ning.sun@intel.com>,
	 x86@kernel.org, tboot-devel@lists.sourceforge.net,
	 Ard Biesheuvel <ardb@kernel.org>,
	 Ilias Apalodimas <ilias.apalodimas@linaro.org>,
	linux-efi@vger.kernel.org,  Vishal Moola <vishal.moola@gmail.com>,
	Alistair Popple <apopple@nvidia.com>,
	 "Matthew Wilcox (Oracle)" <willy@infradead.org>,
	 linux-kernel@vger.kernel.org, linux-arch@vger.kernel.org
Subject: [PATCH 08/22] powerpc: mm: use mm_is_kernel() for kernel mm checks
Date: Tue, 14 Jul 2026 15:03:57 +0100	[thread overview]
Message-ID: <20260714-remove_pgtable_cdtor-v1-8-44be8a7685d7@arm.com> (raw)
In-Reply-To: <20260714-remove_pgtable_cdtor-v1-0-44be8a7685d7@arm.com>

The new MMF_KERNEL flag identifies kernel-owned mm's. Checking the
flag with mm_is_kernel() is preferred over comparing directly
against &init_mm.

No functional change, as only init_mm has MMF_KERNEL set for now.

Assisted-by: Codex:GPT-5.5
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
---
 arch/powerpc/include/asm/pgalloc.h | 2 +-
 arch/powerpc/mm/book3s64/pgtable.c | 2 +-
 arch/powerpc/mm/mmu_context.c      | 2 +-
 arch/powerpc/mm/pgtable.c          | 2 +-
 4 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/arch/powerpc/include/asm/pgalloc.h b/arch/powerpc/include/asm/pgalloc.h
index 3a971e2a8c73..88acccc5b06e 100644
--- a/arch/powerpc/include/asm/pgalloc.h
+++ b/arch/powerpc/include/asm/pgalloc.h
@@ -7,7 +7,7 @@
 #ifndef MODULE
 static inline gfp_t pgtable_gfp_flags(struct mm_struct *mm, gfp_t gfp)
 {
-	if (unlikely(mm == &init_mm))
+	if (unlikely(mm_is_kernel(mm)))
 		return gfp;
 	return gfp | __GFP_ACCOUNT;
 }
diff --git a/arch/powerpc/mm/book3s64/pgtable.c b/arch/powerpc/mm/book3s64/pgtable.c
index 85ab6723c8f2..eb365f7c8907 100644
--- a/arch/powerpc/mm/book3s64/pgtable.c
+++ b/arch/powerpc/mm/book3s64/pgtable.c
@@ -395,7 +395,7 @@ static pmd_t *__alloc_for_pmdcache(struct mm_struct *mm)
 	struct ptdesc *ptdesc;
 	gfp_t gfp = GFP_KERNEL_ACCOUNT | __GFP_ZERO;
 
-	if (mm == &init_mm)
+	if (mm_is_kernel(mm))
 		gfp &= ~__GFP_ACCOUNT;
 	ptdesc = pagetable_alloc(gfp, 0);
 	if (!ptdesc)
diff --git a/arch/powerpc/mm/mmu_context.c b/arch/powerpc/mm/mmu_context.c
index 3e3af29b4523..b51934c511f3 100644
--- a/arch/powerpc/mm/mmu_context.c
+++ b/arch/powerpc/mm/mmu_context.c
@@ -48,7 +48,7 @@ void switch_mm_irqs_off(struct mm_struct *prev, struct mm_struct *next,
 
 	/* Mark this context has been used on the new CPU */
 	if (!cpumask_test_cpu(cpu, mm_cpumask(next))) {
-		VM_WARN_ON_ONCE(next == &init_mm);
+		VM_WARN_ON_ONCE(mm_is_kernel(next));
 		cpumask_set_cpu(cpu, mm_cpumask(next));
 		inc_mm_active_cpus(next);
 
diff --git a/arch/powerpc/mm/pgtable.c b/arch/powerpc/mm/pgtable.c
index a9be337be3e4..d04f4fecfc7c 100644
--- a/arch/powerpc/mm/pgtable.c
+++ b/arch/powerpc/mm/pgtable.c
@@ -393,7 +393,7 @@ void assert_pte_locked(struct mm_struct *mm, unsigned long addr)
 	pte_t *pte;
 	spinlock_t *ptl;
 
-	if (mm == &init_mm)
+	if (mm_is_kernel(mm))
 		return;
 	pgd = mm->pgd + pgd_index(addr);
 	BUG_ON(pgd_none(*pgd));

-- 
2.51.2


  parent reply	other threads:[~2026-07-14 14:06 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 ` Kevin Brodsky [this message]
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 ` [PATCH 18/22] arm64: mm: drop explicit mm_is_efi() check in contpte Kevin Brodsky
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

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20260714-remove_pgtable_cdtor-v1-8-44be8a7685d7@arm.com \
    --to=kevin.brodsky@arm.com \
    --cc=James.Bottomley@HansenPartnership.com \
    --cc=agordeev@linux.ibm.com \
    --cc=akpm@linux-foundation.org \
    --cc=andreas@gaisler.com \
    --cc=anton.ivanov@cambridgegreys.com \
    --cc=aou@eecs.berkeley.edu \
    --cc=apopple@nvidia.com \
    --cc=ardb@kernel.org \
    --cc=bp@alien8.de \
    --cc=catalin.marinas@arm.com \
    --cc=chenhuacai@kernel.org \
    --cc=dave.hansen@linux.intel.com \
    --cc=davem@davemloft.net \
    --cc=david@kernel.org \
    --cc=deller@gmx.de \
    --cc=gerald.schaefer@linux.ibm.com \
    --cc=gor@linux.ibm.com \
    --cc=hca@linux.ibm.com \
    --cc=hpa@zytor.com \
    --cc=ilias.apalodimas@linaro.org \
    --cc=johannes@sipsolutions.net \
    --cc=liam@infradead.org \
    --cc=linux-arch@vger.kernel.org \
    --cc=linux-arm-kernel@lists.infradead.org \
    --cc=linux-efi@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-mm@kvack.org \
    --cc=linux-parisc@vger.kernel.org \
    --cc=linux-riscv@lists.infradead.org \
    --cc=linux-s390@vger.kernel.org \
    --cc=linux-um@lists.infradead.org \
    --cc=linux@armlinux.org.uk \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=ljs@kernel.org \
    --cc=loongarch@lists.linux.dev \
    --cc=luto@kernel.org \
    --cc=maddy@linux.ibm.com \
    --cc=mhocko@suse.com \
    --cc=mingo@redhat.com \
    --cc=mpe@ellerman.id.au \
    --cc=ning.sun@intel.com \
    --cc=palmer@dabbelt.com \
    --cc=pasha.tatashin@soleen.com \
    --cc=peterz@infradead.org \
    --cc=pjw@kernel.org \
    --cc=richard@nod.at \
    --cc=rppt@kernel.org \
    --cc=ryan.roberts@arm.com \
    --cc=sparclinux@vger.kernel.org \
    --cc=surenb@google.com \
    --cc=tboot-devel@lists.sourceforge.net \
    --cc=tglx@kernel.org \
    --cc=vbabka@kernel.org \
    --cc=vishal.moola@gmail.com \
    --cc=will@kernel.org \
    --cc=willy@infradead.org \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox