[PATCH 08/22] powerpc: mm: use mm_is_kernel() for kernel mm checks

From: Kevin Brodsky <kevin.brodsky@arm.com>
To: linux-mm@kvack.org
Cc: Kevin Brodsky <kevin.brodsky@arm.com>,
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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

