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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Subject: [PATCH 16/22] efi: mark efi_mm as a kernel mm
Date: Tue, 14 Jul 2026 15:04:05 +0100 [thread overview]
Message-ID: <20260714-remove_pgtable_cdtor-v1-16-44be8a7685d7@arm.com> (raw)
In-Reply-To: <20260714-remove_pgtable_cdtor-v1-0-44be8a7685d7@arm.com>
efi_mm is a kernel-owned address space used for EFI runtime
mappings, but it is currently treated like a user address space when
manipulating its page tables. There does not seem to be a good
reason for this, and it creates unnecessary complications when
creating its page tables.
Mark it with the new MMF_KERNEL flag so that the page table handling
treats it like init_mm. In particular, this means that:
* Split page table locks are no longer initialised or used for
efi_mm's page tables.
* pagetable_*_ctor() and pagetable_dtor() no longer need to be
called for efi_mm's page tables.
Assisted-by: Codex:GPT-5.5
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
---
drivers/firmware/efi/efi.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/drivers/firmware/efi/efi.c b/drivers/firmware/efi/efi.c
index 0327a39d31fa..e5ca45bdc890 100644
--- a/drivers/firmware/efi/efi.c
+++ b/drivers/firmware/efi/efi.c
@@ -69,6 +69,7 @@ struct mm_struct efi_mm = {
.mm_mt = MTREE_INIT_EXT(mm_mt, MM_MT_FLAGS, efi_mm.mmap_lock),
.mm_users = ATOMIC_INIT(2),
.mm_count = ATOMIC_INIT(1),
+ .flags = MM_FLAGS_INIT(MMF_KERNEL_MASK),
.write_protect_seq = SEQCNT_ZERO(efi_mm.write_protect_seq),
MMAP_LOCK_INITIALIZER(efi_mm)
.page_table_lock = __SPIN_LOCK_UNLOCKED(efi_mm.page_table_lock),
--
2.51.2
next prev 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 ` Kevin Brodsky [this message]
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
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