From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Kevin Brodsky <kevin.brodsky@arm.com>,
linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org,
"David Hildenbrand (Arm)" <david@kernel.org>,
Ryan Roberts <ryan.roberts@arm.com>,
Catalin Marinas <catalin.marinas@arm.com>,
Will Deacon <will@kernel.org>
Subject: Re: [PATCH v2] arm64: mm: Use generic enum pgtable_level
Date: Wed, 18 Mar 2026 15:37:24 +0530 [thread overview]
Message-ID: <1978ee53-1cb7-4bc2-a205-813f26a11076@arm.com> (raw)
In-Reply-To: <20260318092543.73331-1-kevin.brodsky@arm.com>
On 18/03/26 2:55 PM, Kevin Brodsky wrote:
> enum pgtable_type was introduced for arm64 by commit c64f46ee1377
> ("arm64: mm: use enum to identify pgtable level instead of
> *_SHIFT"). In the meantime, the generic enum pgtable_level got
> introduced by commit b22cc9a9c7ff ("mm/rmap: convert "enum
> rmap_level" to "enum pgtable_level"").
>
> Let's switch to the generic enum pgtable_level. The only difference
> is that it also includes PGD level; __pgd_pgtable_alloc() isn't
> expected to create PGD tables so we add a VM_WARN_ON() for that
> case.
>
> Suggested-by: David Hildenbrand (Arm) <david@kernel.org>
> Reviewed-by: David Hildenbrand (Arm) <david@kernel.org>
> Reviewed-by: Ryan Roberts <ryan.roberts@arm.com>
> Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
> ---
> v1..v2:
> - Add a VM_WARN_ON() for PGD in __pgd_pgtable_alloc() [Ryan, David]
>
> Cc: Catalin Marinas <catalin.marinas@arm.com>
> Cc: Will Deacon <will@kernel.org>
> ---
> arch/arm64/include/asm/mmu.h | 7 -----
> arch/arm64/mm/mmu.c | 59 +++++++++++++++++++-----------------
> 2 files changed, 31 insertions(+), 35 deletions(-)
>
> diff --git a/arch/arm64/include/asm/mmu.h b/arch/arm64/include/asm/mmu.h
> index 137a173df1ff..f28e6e215da4 100644
> --- a/arch/arm64/include/asm/mmu.h
> +++ b/arch/arm64/include/asm/mmu.h
> @@ -17,13 +17,6 @@
> #include <linux/refcount.h>
> #include <asm/cpufeature.h>
>
> -enum pgtable_type {
> - TABLE_PTE,
> - TABLE_PMD,
> - TABLE_PUD,
> - TABLE_P4D,
> -};
> -
> typedef struct {
> atomic64_t id;
> #ifdef CONFIG_COMPAT
> diff --git a/arch/arm64/mm/mmu.c b/arch/arm64/mm/mmu.c
> index a6a00accf4f9..c45a6a47dad0 100644
> --- a/arch/arm64/mm/mmu.c
> +++ b/arch/arm64/mm/mmu.c
> @@ -112,7 +112,7 @@ pgprot_t phys_mem_access_prot(struct file *file, unsigned long pfn,
> }
> EXPORT_SYMBOL(phys_mem_access_prot);
>
> -static phys_addr_t __init early_pgtable_alloc(enum pgtable_type pgtable_type)
> +static phys_addr_t __init early_pgtable_alloc(enum pgtable_level pgtable_level)
> {
> phys_addr_t phys;
>
> @@ -197,7 +197,7 @@ static void init_pte(pte_t *ptep, unsigned long addr, unsigned long end,
> static int alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr,
> unsigned long end, phys_addr_t phys,
> pgprot_t prot,
> - phys_addr_t (*pgtable_alloc)(enum pgtable_type),
> + phys_addr_t (*pgtable_alloc)(enum pgtable_level),
> int flags)
> {
> unsigned long next;
> @@ -212,7 +212,7 @@ static int alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr,
> if (flags & NO_EXEC_MAPPINGS)
> pmdval |= PMD_TABLE_PXN;
> BUG_ON(!pgtable_alloc);
> - pte_phys = pgtable_alloc(TABLE_PTE);
> + pte_phys = pgtable_alloc(PGTABLE_LEVEL_PTE);
> if (pte_phys == INVALID_PHYS_ADDR)
> return -ENOMEM;
> ptep = pte_set_fixmap(pte_phys);
> @@ -252,7 +252,7 @@ static int alloc_init_cont_pte(pmd_t *pmdp, unsigned long addr,
>
> static int init_pmd(pmd_t *pmdp, unsigned long addr, unsigned long end,
> phys_addr_t phys, pgprot_t prot,
> - phys_addr_t (*pgtable_alloc)(enum pgtable_type), int flags)
> + phys_addr_t (*pgtable_alloc)(enum pgtable_level), int flags)
> {
> unsigned long next;
>
> @@ -292,7 +292,7 @@ static int init_pmd(pmd_t *pmdp, unsigned long addr, unsigned long end,
> static int alloc_init_cont_pmd(pud_t *pudp, unsigned long addr,
> unsigned long end, phys_addr_t phys,
> pgprot_t prot,
> - phys_addr_t (*pgtable_alloc)(enum pgtable_type),
> + phys_addr_t (*pgtable_alloc)(enum pgtable_level),
> int flags)
> {
> int ret;
> @@ -311,7 +311,7 @@ static int alloc_init_cont_pmd(pud_t *pudp, unsigned long addr,
> if (flags & NO_EXEC_MAPPINGS)
> pudval |= PUD_TABLE_PXN;
> BUG_ON(!pgtable_alloc);
> - pmd_phys = pgtable_alloc(TABLE_PMD);
> + pmd_phys = pgtable_alloc(PGTABLE_LEVEL_PMD);
> if (pmd_phys == INVALID_PHYS_ADDR)
> return -ENOMEM;
> pmdp = pmd_set_fixmap(pmd_phys);
> @@ -349,7 +349,7 @@ static int alloc_init_cont_pmd(pud_t *pudp, unsigned long addr,
>
> static int alloc_init_pud(p4d_t *p4dp, unsigned long addr, unsigned long end,
> phys_addr_t phys, pgprot_t prot,
> - phys_addr_t (*pgtable_alloc)(enum pgtable_type),
> + phys_addr_t (*pgtable_alloc)(enum pgtable_level),
> int flags)
> {
> int ret = 0;
> @@ -364,7 +364,7 @@ static int alloc_init_pud(p4d_t *p4dp, unsigned long addr, unsigned long end,
> if (flags & NO_EXEC_MAPPINGS)
> p4dval |= P4D_TABLE_PXN;
> BUG_ON(!pgtable_alloc);
> - pud_phys = pgtable_alloc(TABLE_PUD);
> + pud_phys = pgtable_alloc(PGTABLE_LEVEL_PUD);
> if (pud_phys == INVALID_PHYS_ADDR)
> return -ENOMEM;
> pudp = pud_set_fixmap(pud_phys);
> @@ -415,7 +415,7 @@ static int alloc_init_pud(p4d_t *p4dp, unsigned long addr, unsigned long end,
>
> static int alloc_init_p4d(pgd_t *pgdp, unsigned long addr, unsigned long end,
> phys_addr_t phys, pgprot_t prot,
> - phys_addr_t (*pgtable_alloc)(enum pgtable_type),
> + phys_addr_t (*pgtable_alloc)(enum pgtable_level),
> int flags)
> {
> int ret;
> @@ -430,7 +430,7 @@ static int alloc_init_p4d(pgd_t *pgdp, unsigned long addr, unsigned long end,
> if (flags & NO_EXEC_MAPPINGS)
> pgdval |= PGD_TABLE_PXN;
> BUG_ON(!pgtable_alloc);
> - p4d_phys = pgtable_alloc(TABLE_P4D);
> + p4d_phys = pgtable_alloc(PGTABLE_LEVEL_P4D);
> if (p4d_phys == INVALID_PHYS_ADDR)
> return -ENOMEM;
> p4dp = p4d_set_fixmap(p4d_phys);
> @@ -467,7 +467,7 @@ static int alloc_init_p4d(pgd_t *pgdp, unsigned long addr, unsigned long end,
> static int __create_pgd_mapping_locked(pgd_t *pgdir, phys_addr_t phys,
> unsigned long virt, phys_addr_t size,
> pgprot_t prot,
> - phys_addr_t (*pgtable_alloc)(enum pgtable_type),
> + phys_addr_t (*pgtable_alloc)(enum pgtable_level),
> int flags)
> {
> int ret;
> @@ -500,7 +500,7 @@ static int __create_pgd_mapping_locked(pgd_t *pgdir, phys_addr_t phys,
> static int __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
> unsigned long virt, phys_addr_t size,
> pgprot_t prot,
> - phys_addr_t (*pgtable_alloc)(enum pgtable_type),
> + phys_addr_t (*pgtable_alloc)(enum pgtable_level),
> int flags)
> {
> int ret;
> @@ -516,7 +516,7 @@ static int __create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
> static void early_create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
> unsigned long virt, phys_addr_t size,
> pgprot_t prot,
> - phys_addr_t (*pgtable_alloc)(enum pgtable_type),
> + phys_addr_t (*pgtable_alloc)(enum pgtable_level),
> int flags)
> {
> int ret;
> @@ -528,7 +528,7 @@ static void early_create_pgd_mapping(pgd_t *pgdir, phys_addr_t phys,
> }
>
> static phys_addr_t __pgd_pgtable_alloc(struct mm_struct *mm, gfp_t gfp,
> - enum pgtable_type pgtable_type)
> + enum pgtable_level pgtable_level)
> {
> /* Page is zeroed by init_clear_pgtable() so don't duplicate effort. */
> struct ptdesc *ptdesc = pagetable_alloc(gfp & ~__GFP_ZERO, 0);
> @@ -539,40 +539,43 @@ static phys_addr_t __pgd_pgtable_alloc(struct mm_struct *mm, gfp_t gfp,
>
> pa = page_to_phys(ptdesc_page(ptdesc));
>
> - switch (pgtable_type) {
> - case TABLE_PTE:
> + switch (pgtable_level) {
> + case PGTABLE_LEVEL_PTE:
> BUG_ON(!pagetable_pte_ctor(mm, ptdesc));
> break;
> - case TABLE_PMD:
> + case PGTABLE_LEVEL_PMD:
> BUG_ON(!pagetable_pmd_ctor(mm, ptdesc));
> break;
> - case TABLE_PUD:
> + case PGTABLE_LEVEL_PUD:
> pagetable_pud_ctor(ptdesc);
> break;
> - case TABLE_P4D:
> + case PGTABLE_LEVEL_P4D:
> pagetable_p4d_ctor(ptdesc);
> break;
> + case PGTABLE_LEVEL_PGD:
> + VM_WARN_ON(1);
> + break;
> }
>
> return pa;
> }
>
> static phys_addr_t
> -pgd_pgtable_alloc_init_mm_gfp(enum pgtable_type pgtable_type, gfp_t gfp)
> +pgd_pgtable_alloc_init_mm_gfp(enum pgtable_level pgtable_level, gfp_t gfp)
> {
> - return __pgd_pgtable_alloc(&init_mm, gfp, pgtable_type);
> + return __pgd_pgtable_alloc(&init_mm, gfp, pgtable_level);
> }
>
> static phys_addr_t __maybe_unused
> -pgd_pgtable_alloc_init_mm(enum pgtable_type pgtable_type)
> +pgd_pgtable_alloc_init_mm(enum pgtable_level pgtable_level)
> {
> - return pgd_pgtable_alloc_init_mm_gfp(pgtable_type, GFP_PGTABLE_KERNEL);
> + return pgd_pgtable_alloc_init_mm_gfp(pgtable_level, GFP_PGTABLE_KERNEL);
> }
>
> static phys_addr_t
> -pgd_pgtable_alloc_special_mm(enum pgtable_type pgtable_type)
> +pgd_pgtable_alloc_special_mm(enum pgtable_level pgtable_level)
> {
> - return __pgd_pgtable_alloc(NULL, GFP_PGTABLE_KERNEL, pgtable_type);
> + return __pgd_pgtable_alloc(NULL, GFP_PGTABLE_KERNEL, pgtable_level);
> }
>
> static void split_contpte(pte_t *ptep)
> @@ -593,7 +596,7 @@ static int split_pmd(pmd_t *pmdp, pmd_t pmd, gfp_t gfp, bool to_cont)
> pte_t *ptep;
> int i;
>
> - pte_phys = pgd_pgtable_alloc_init_mm_gfp(TABLE_PTE, gfp);
> + pte_phys = pgd_pgtable_alloc_init_mm_gfp(PGTABLE_LEVEL_PTE, gfp);
> if (pte_phys == INVALID_PHYS_ADDR)
> return -ENOMEM;
> ptep = (pte_t *)phys_to_virt(pte_phys);
> @@ -638,7 +641,7 @@ static int split_pud(pud_t *pudp, pud_t pud, gfp_t gfp, bool to_cont)
> pmd_t *pmdp;
> int i;
>
> - pmd_phys = pgd_pgtable_alloc_init_mm_gfp(TABLE_PMD, gfp);
> + pmd_phys = pgd_pgtable_alloc_init_mm_gfp(PGTABLE_LEVEL_PMD, gfp);
> if (pmd_phys == INVALID_PHYS_ADDR)
> return -ENOMEM;
> pmdp = (pmd_t *)phys_to_virt(pmd_phys);
> @@ -1226,7 +1229,7 @@ static void __init declare_vma(struct vm_struct *vma,
>
> static phys_addr_t kpti_ng_temp_alloc __initdata;
>
> -static phys_addr_t __init kpti_ng_pgd_alloc(enum pgtable_type type)
> +static phys_addr_t __init kpti_ng_pgd_alloc(enum pgtable_level pgtable_level)
> {
> kpti_ng_temp_alloc -= PAGE_SIZE;
> return kpti_ng_temp_alloc;
next prev parent reply other threads:[~2026-03-18 10:07 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-03-18 9:25 Kevin Brodsky
2026-03-18 10:07 ` Anshuman Khandual [this message]
2026-04-01 18:13 ` Catalin Marinas
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