On Tue, Apr 08, 2025 at 10:52:11AM +0100, Kevin Brodsky wrote:
> In preparation for calling constructors for all kernel page tables
> while eliding unnecessary ptlock initialisation, let's pass down the
> associated mm to the PTE/PMD level ctors. (These are the two levels
> where ptlocks are used.)
>
> In most cases the mm is already around at the point of calling the
> ctor so we simply pass it down. This is however not the case for
> special page table allocators:
>
> * arch/arm/mm/mmu.c
> * arch/arm64/mm/mmu.c
> * arch/riscv/mm/init.c
>
> In those cases, the page tables being allocated are either for
> standard kernel memory (init_mm) or special page directories, which
> may not be associated to any mm. For now let's pass NULL as mm; this
> will be refined where possible in future patches.
>
> No functional change in this patch.
>
> Signed-off-by: Kevin Brodsky <kevin.brod...@arm.com>
> ---
> arch/arm/mm/mmu.c | 2 +-
> arch/arm64/mm/mmu.c | 4 ++--
> arch/loongarch/include/asm/pgalloc.h | 2 +-
> arch/m68k/include/asm/mcf_pgalloc.h | 2 +-
> arch/m68k/include/asm/motorola_pgalloc.h | 10 +++++-----
> arch/m68k/mm/motorola.c | 6 +++---
> arch/mips/include/asm/pgalloc.h | 2 +-
> arch/parisc/include/asm/pgalloc.h | 2 +-
> arch/powerpc/mm/book3s64/pgtable.c | 2 +-
> arch/powerpc/mm/pgtable-frag.c | 2 +-
> arch/riscv/mm/init.c | 4 ++--
> arch/s390/include/asm/pgalloc.h | 2 +-
> arch/s390/mm/pgalloc.c | 2 +-
> arch/sparc/mm/init_64.c | 2 +-
> arch/sparc/mm/srmmu.c | 2 +-
> arch/x86/mm/pgtable.c | 2 +-
> include/asm-generic/pgalloc.h | 4 ++--
> include/linux/mm.h | 6 ++++--
> 18 files changed, 30 insertions(+), 28 deletions(-)
>
> diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
> index f02f872ea8a9..edb7f56b7c91 100644
> --- a/arch/arm/mm/mmu.c
> +++ b/arch/arm/mm/mmu.c
> @@ -735,7 +735,7 @@ static void *__init late_alloc(unsigned long sz)
> void *ptdesc = pagetable_alloc(GFP_PGTABLE_KERNEL & ~__GFP_HIGHMEM,
> get_order(sz));
>
> - if (!ptdesc || !pagetable_pte_ctor(ptdesc))
> + if (!ptdesc || !pagetable_pte_ctor(NULL, ptdesc))
> BUG();
> return ptdesc_to_virt(ptdesc);
> }
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index ea6695d53fb9..8c5c471cfb06 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -494,9 +494,9 @@ static phys_addr_t pgd_pgtable_alloc(int shift)
> * folded, and if so pagetable_pte_ctor() becomes nop.
> */
> if (shift == PAGE_SHIFT)
> - BUG_ON(!pagetable_pte_ctor(ptdesc));
> + BUG_ON(!pagetable_pte_ctor(NULL, ptdesc));
> else if (shift == PMD_SHIFT)
> - BUG_ON(!pagetable_pmd_ctor(ptdesc));
> + BUG_ON(!pagetable_pmd_ctor(NULL, ptdesc));
>
> return pa;
> }
> diff --git a/arch/loongarch/include/asm/pgalloc.h
> b/arch/loongarch/include/asm/pgalloc.h
> index b58f587f0f0a..1c63a9d9a6d3 100644
> --- a/arch/loongarch/include/asm/pgalloc.h
> +++ b/arch/loongarch/include/asm/pgalloc.h
> @@ -69,7 +69,7 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm,
> unsigned long address)
> if (!ptdesc)
> return NULL;
>
> - if (!pagetable_pmd_ctor(ptdesc)) {
> + if (!pagetable_pmd_ctor(mm, ptdesc)) {
> pagetable_free(ptdesc);
> return NULL;
> }
> diff --git a/arch/m68k/include/asm/mcf_pgalloc.h
> b/arch/m68k/include/asm/mcf_pgalloc.h
> index 4c648b51e7fd..465a71101b7d 100644
> --- a/arch/m68k/include/asm/mcf_pgalloc.h
> +++ b/arch/m68k/include/asm/mcf_pgalloc.h
> @@ -48,7 +48,7 @@ static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
>
> if (!ptdesc)
> return NULL;
> - if (!pagetable_pte_ctor(ptdesc)) {
> + if (!pagetable_pte_ctor(mm, ptdesc)) {
> pagetable_free(ptdesc);
> return NULL;
> }
> diff --git a/arch/m68k/include/asm/motorola_pgalloc.h
> b/arch/m68k/include/asm/motorola_pgalloc.h
> index 5abe7da8ac5a..1091fb0affbe 100644
> --- a/arch/m68k/include/asm/motorola_pgalloc.h
> +++ b/arch/m68k/include/asm/motorola_pgalloc.h
> @@ -15,7 +15,7 @@ enum m68k_table_types {
> };
>
> extern void init_pointer_table(void *table, int type);
> -extern void *get_pointer_table(int type);
> +extern void *get_pointer_table(struct mm_struct *mm, int type);
> extern int free_pointer_table(void *table, int type);
>
> /*
> @@ -26,7 +26,7 @@ extern int free_pointer_table(void *table, int type);
>
> static inline pte_t *pte_alloc_one_kernel(struct mm_struct *mm)
> {
> - return get_pointer_table(TABLE_PTE);
> + return get_pointer_table(mm, TABLE_PTE);
> }
>
> static inline void pte_free_kernel(struct mm_struct *mm, pte_t *pte)
> @@ -36,7 +36,7 @@ static inline void pte_free_kernel(struct mm_struct *mm,
> pte_t *pte)
>
> static inline pgtable_t pte_alloc_one(struct mm_struct *mm)
> {
> - return get_pointer_table(TABLE_PTE);
> + return get_pointer_table(mm, TABLE_PTE);
> }
>
> static inline void pte_free(struct mm_struct *mm, pgtable_t pgtable)
> @@ -53,7 +53,7 @@ static inline void __pte_free_tlb(struct mmu_gather *tlb,
> pgtable_t pgtable,
>
> static inline pmd_t *pmd_alloc_one(struct mm_struct *mm, unsigned long
> address)
> {
> - return get_pointer_table(TABLE_PMD);
> + return get_pointer_table(mm, TABLE_PMD);
> }
>
> static inline int pmd_free(struct mm_struct *mm, pmd_t *pmd)
> @@ -75,7 +75,7 @@ static inline void pgd_free(struct mm_struct *mm, pgd_t
> *pgd)
>
> static inline pgd_t *pgd_alloc(struct mm_struct *mm)
> {
> - return get_pointer_table(TABLE_PGD);
> + return get_pointer_table(mm, TABLE_PGD);
> }
>
>
> diff --git a/arch/m68k/mm/motorola.c b/arch/m68k/mm/motorola.c
> index 73651e093c4d..6ab3ef39ba7a 100644
> --- a/arch/m68k/mm/motorola.c
> +++ b/arch/m68k/mm/motorola.c
> @@ -139,7 +139,7 @@ void __init init_pointer_table(void *table, int type)
> return;
> }
>
> -void *get_pointer_table(int type)
> +void *get_pointer_table(struct mm_struct *mm, int type)
> {
> ptable_desc *dp = ptable_list[type].next;
> unsigned int mask = list_empty(&ptable_list[type]) ? 0 :
> PD_MARKBITS(dp);
> @@ -164,10 +164,10 @@ void *get_pointer_table(int type)
> * m68k doesn't have SPLIT_PTE_PTLOCKS for not having
> * SMP.
> */
> - pagetable_pte_ctor(virt_to_ptdesc(page));
> + pagetable_pte_ctor(mm, virt_to_ptdesc(page));
> break;
> case TABLE_PMD:
> - pagetable_pmd_ctor(virt_to_ptdesc(page));
> + pagetable_pmd_ctor(mm, virt_to_ptdesc(page));
> break;
> case TABLE_PGD:
> pagetable_pgd_ctor(virt_to_ptdesc(page));
> diff --git a/arch/mips/include/asm/pgalloc.h b/arch/mips/include/asm/pgalloc.h
> index bbca420c96d3..942af87f1cdd 100644
> --- a/arch/mips/include/asm/pgalloc.h
> +++ b/arch/mips/include/asm/pgalloc.h
> @@ -62,7 +62,7 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm,
> unsigned long address)
> if (!ptdesc)
> return NULL;
>
> - if (!pagetable_pmd_ctor(ptdesc)) {
> + if (!pagetable_pmd_ctor(mm, ptdesc)) {
> pagetable_free(ptdesc);
> return NULL;
> }
> diff --git a/arch/parisc/include/asm/pgalloc.h
> b/arch/parisc/include/asm/pgalloc.h
> index 2ca74a56415c..3b84ee93edaa 100644
> --- a/arch/parisc/include/asm/pgalloc.h
> +++ b/arch/parisc/include/asm/pgalloc.h
> @@ -39,7 +39,7 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm,
> unsigned long address)
> ptdesc = pagetable_alloc(gfp, PMD_TABLE_ORDER);
> if (!ptdesc)
> return NULL;
> - if (!pagetable_pmd_ctor(ptdesc)) {
> + if (!pagetable_pmd_ctor(mm, ptdesc)) {
> pagetable_free(ptdesc);
> return NULL;
> }
> diff --git a/arch/powerpc/mm/book3s64/pgtable.c
> b/arch/powerpc/mm/book3s64/pgtable.c
> index 8f7d41ce2ca1..a282233c8785 100644
> --- a/arch/powerpc/mm/book3s64/pgtable.c
> +++ b/arch/powerpc/mm/book3s64/pgtable.c
> @@ -422,7 +422,7 @@ static pmd_t *__alloc_for_pmdcache(struct mm_struct *mm)
> ptdesc = pagetable_alloc(gfp, 0);
> if (!ptdesc)
> return NULL;
> - if (!pagetable_pmd_ctor(ptdesc)) {
> + if (!pagetable_pmd_ctor(mm, ptdesc)) {
> pagetable_free(ptdesc);
> return NULL;
> }
> diff --git a/arch/powerpc/mm/pgtable-frag.c b/arch/powerpc/mm/pgtable-frag.c
> index 713268ccb1a0..387e9b1fe12c 100644
> --- a/arch/powerpc/mm/pgtable-frag.c
> +++ b/arch/powerpc/mm/pgtable-frag.c
> @@ -61,7 +61,7 @@ static pte_t *__alloc_for_ptecache(struct mm_struct *mm,
> int kernel)
> ptdesc = pagetable_alloc(PGALLOC_GFP | __GFP_ACCOUNT, 0);
> if (!ptdesc)
> return NULL;
> - if (!pagetable_pte_ctor(ptdesc)) {
> + if (!pagetable_pte_ctor(mm, ptdesc)) {
> pagetable_free(ptdesc);
> return NULL;
> }
> diff --git a/arch/riscv/mm/init.c b/arch/riscv/mm/init.c
> index ab475ec6ca42..e5ef693fc778 100644
> --- a/arch/riscv/mm/init.c
> +++ b/arch/riscv/mm/init.c
> @@ -442,7 +442,7 @@ static phys_addr_t __meminit alloc_pte_late(uintptr_t va)
> {
> struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
>
> - BUG_ON(!ptdesc || !pagetable_pte_ctor(ptdesc));
> + BUG_ON(!ptdesc || !pagetable_pte_ctor(NULL, ptdesc));
> return __pa((pte_t *)ptdesc_address(ptdesc));
> }
>
> @@ -522,7 +522,7 @@ static phys_addr_t __meminit alloc_pmd_late(uintptr_t va)
> {
> struct ptdesc *ptdesc = pagetable_alloc(GFP_KERNEL & ~__GFP_HIGHMEM, 0);
>
> - BUG_ON(!ptdesc || !pagetable_pmd_ctor(ptdesc));
> + BUG_ON(!ptdesc || !pagetable_pmd_ctor(NULL, ptdesc));
> return __pa((pmd_t *)ptdesc_address(ptdesc));
> }
>
> diff --git a/arch/s390/include/asm/pgalloc.h b/arch/s390/include/asm/pgalloc.h
> index 005497ffebda..5345398df653 100644
> --- a/arch/s390/include/asm/pgalloc.h
> +++ b/arch/s390/include/asm/pgalloc.h
> @@ -97,7 +97,7 @@ static inline pmd_t *pmd_alloc_one(struct mm_struct *mm,
> unsigned long vmaddr)
> if (!table)
> return NULL;
> crst_table_init(table, _SEGMENT_ENTRY_EMPTY);
> - if (!pagetable_pmd_ctor(virt_to_ptdesc(table))) {
> + if (!pagetable_pmd_ctor(mm, virt_to_ptdesc(table))) {
> crst_table_free(mm, table);
> return NULL;
> }
> diff --git a/arch/s390/mm/pgalloc.c b/arch/s390/mm/pgalloc.c
> index e3a6f8ae156c..619d6917e3b7 100644
> --- a/arch/s390/mm/pgalloc.c
> +++ b/arch/s390/mm/pgalloc.c
> @@ -145,7 +145,7 @@ unsigned long *page_table_alloc(struct mm_struct *mm)
> ptdesc = pagetable_alloc(GFP_KERNEL, 0);
> if (!ptdesc)
> return NULL;
> - if (!pagetable_pte_ctor(ptdesc)) {
> + if (!pagetable_pte_ctor(mm, ptdesc)) {
> pagetable_free(ptdesc);
> return NULL;
> }
> diff --git a/arch/sparc/mm/init_64.c b/arch/sparc/mm/init_64.c
> index 760818950464..5c8eabda1d17 100644
> --- a/arch/sparc/mm/init_64.c
> +++ b/arch/sparc/mm/init_64.c
> @@ -2895,7 +2895,7 @@ pgtable_t pte_alloc_one(struct mm_struct *mm)
>
> if (!ptdesc)
> return NULL;
> - if (!pagetable_pte_ctor(ptdesc)) {
> + if (!pagetable_pte_ctor(mm, ptdesc)) {
> pagetable_free(ptdesc);
> return NULL;
> }
> diff --git a/arch/sparc/mm/srmmu.c b/arch/sparc/mm/srmmu.c
> index dd32711022f5..f8fb4911d360 100644
> --- a/arch/sparc/mm/srmmu.c
> +++ b/arch/sparc/mm/srmmu.c
> @@ -350,7 +350,7 @@ pgtable_t pte_alloc_one(struct mm_struct *mm)
> page = pfn_to_page(__nocache_pa((unsigned long)ptep) >> PAGE_SHIFT);
> spin_lock(&mm->page_table_lock);
> if (page_ref_inc_return(page) == 2 &&
> - !pagetable_pte_ctor(page_ptdesc(page))) {
> + !pagetable_pte_ctor(mm, page_ptdesc(page))) {
> page_ref_dec(page);
> ptep = NULL;
> }
> diff --git a/arch/x86/mm/pgtable.c b/arch/x86/mm/pgtable.c
> index a05fcddfc811..7930f234c5f6 100644
> --- a/arch/x86/mm/pgtable.c
> +++ b/arch/x86/mm/pgtable.c
> @@ -205,7 +205,7 @@ static int preallocate_pmds(struct mm_struct *mm, pmd_t
> *pmds[], int count)
>
> if (!ptdesc)
> failed = true;
> - if (ptdesc && !pagetable_pmd_ctor(ptdesc)) {
> + if (ptdesc && !pagetable_pmd_ctor(mm, ptdesc)) {
> pagetable_free(ptdesc);
> ptdesc = NULL;
> failed = true;
> diff --git a/include/asm-generic/pgalloc.h b/include/asm-generic/pgalloc.h
> index 892ece4558a2..e164ca66f0f6 100644
> --- a/include/asm-generic/pgalloc.h
> +++ b/include/asm-generic/pgalloc.h
> @@ -70,7 +70,7 @@ static inline pgtable_t __pte_alloc_one_noprof(struct
> mm_struct *mm, gfp_t gfp)
> ptdesc = pagetable_alloc_noprof(gfp, 0);
> if (!ptdesc)
> return NULL;
> - if (!pagetable_pte_ctor(ptdesc)) {
> + if (!pagetable_pte_ctor(mm, ptdesc)) {
> pagetable_free(ptdesc);
> return NULL;
> }
> @@ -137,7 +137,7 @@ static inline pmd_t *pmd_alloc_one_noprof(struct
> mm_struct *mm, unsigned long ad
> ptdesc = pagetable_alloc_noprof(gfp, 0);
> if (!ptdesc)
> return NULL;
> - if (!pagetable_pmd_ctor(ptdesc)) {
> + if (!pagetable_pmd_ctor(mm, ptdesc)) {
> pagetable_free(ptdesc);
> return NULL;
> }
> diff --git a/include/linux/mm.h b/include/linux/mm.h
> index b7f13f087954..f9b793cce2c1 100644
> --- a/include/linux/mm.h
> +++ b/include/linux/mm.h
> @@ -3100,7 +3100,8 @@ static inline void pagetable_dtor_free(struct ptdesc
> *ptdesc)
> pagetable_free(ptdesc);
> }
>
> -static inline bool pagetable_pte_ctor(struct ptdesc *ptdesc)
> +static inline bool pagetable_pte_ctor(struct mm_struct *mm,
> + struct ptdesc *ptdesc)
> {
> if (!ptlock_init(ptdesc))
> return false;
> @@ -3206,7 +3207,8 @@ static inline spinlock_t *pmd_lock(struct mm_struct
> *mm, pmd_t *pmd)
> return ptl;
> }
>
> -static inline bool pagetable_pmd_ctor(struct ptdesc *ptdesc)
> +static inline bool pagetable_pmd_ctor(struct mm_struct *mm,
> + struct ptdesc *ptdesc)
> {
> if (!pmd_ptlock_init(ptdesc))
> return false;
Reviewed-by: Alexander Gordeev <agord...@linux.ibm.com> # s390
