From: Catalin Marinas <catalin.marinas@arm.com>
To: Anshuman Khandual <anshuman.khandual@arm.com>
Cc: linux-arm-kernel@lists.infradead.org, mark.rutland@arm.com,
suzuki.poulose@arm.com, Will Deacon <will@kernel.org>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arm64/mm: Add pud_sect_supported()
Date: Thu, 16 Sep 2021 17:16:29 +0100 [thread overview]
Message-ID: <YUNt3btNlYVGDTkX@arm.com> (raw)
In-Reply-To: <1631677459-28383-1-git-send-email-anshuman.khandual@arm.com>
On Wed, Sep 15, 2021 at 09:14:19AM +0530, Anshuman Khandual wrote:
> diff --git a/arch/arm64/mm/hugetlbpage.c b/arch/arm64/mm/hugetlbpage.c
> index 23505fc35324..641854f0e8ee 100644
> --- a/arch/arm64/mm/hugetlbpage.c
> +++ b/arch/arm64/mm/hugetlbpage.c
> @@ -40,11 +40,10 @@ void __init arm64_hugetlb_cma_reserve(void)
> {
> int order;
>
> -#ifdef CONFIG_ARM64_4K_PAGES
> - order = PUD_SHIFT - PAGE_SHIFT;
> -#else
> - order = CONT_PMD_SHIFT + PMD_SHIFT - PAGE_SHIFT;
> -#endif
> + if (pud_sect_supported())
> + order = PUD_SHIFT - PAGE_SHIFT;
> + else
> + order = CONT_PMD_SHIFT + PMD_SHIFT - PAGE_SHIFT;
> /*
> * HugeTLB CMA reservation is required for gigantic
> * huge pages which could not be allocated via the
> @@ -62,8 +61,9 @@ bool arch_hugetlb_migration_supported(struct hstate *h)
> size_t pagesize = huge_page_size(h);
>
> switch (pagesize) {
> -#ifdef CONFIG_ARM64_4K_PAGES
> +#ifndef __PAGETABLE_PUD_FOLDED
> case PUD_SIZE:
> + return pud_sect_supported();
> #endif
> case PMD_SIZE:
> case CONT_PMD_SIZE:
Is this the same thing? With 4K pages and 3-levels (39-bit VA), the PUD
is folded but we do have a valid PUD_SIZE == PGDIR_SIZE and different
from PMD_SIZE. Do we disallow section mappings at the top level in this
case? If not, we should have check for __PAGETABLE_PMD_FOLDED instead.
> @@ -126,8 +126,11 @@ static inline int num_contig_ptes(unsigned long size, size_t *pgsize)
> *pgsize = size;
>
> switch (size) {
> -#ifdef CONFIG_ARM64_4K_PAGES
> +#ifndef __PAGETABLE_PUD_FOLDED
> case PUD_SIZE:
> + if (pud_sect_supported())
> + contig_ptes = 1;
> + break;
> #endif
> case PMD_SIZE:
> contig_ptes = 1;
Same here.
> @@ -489,9 +492,9 @@ void huge_ptep_clear_flush(struct vm_area_struct *vma,
>
> static int __init hugetlbpage_init(void)
> {
> -#ifdef CONFIG_ARM64_4K_PAGES
> - hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
> -#endif
> + if (pud_sect_supported())
> + hugetlb_add_hstate(PUD_SHIFT - PAGE_SHIFT);
> +
> hugetlb_add_hstate(CONT_PMD_SHIFT - PAGE_SHIFT);
> hugetlb_add_hstate(PMD_SHIFT - PAGE_SHIFT);
> hugetlb_add_hstate(CONT_PTE_SHIFT - PAGE_SHIFT);
> @@ -503,8 +506,9 @@ arch_initcall(hugetlbpage_init);
> bool __init arch_hugetlb_valid_size(unsigned long size)
> {
> switch (size) {
> -#ifdef CONFIG_ARM64_4K_PAGES
> +#ifndef __PAGETABLE_PUD_FOLDED
> case PUD_SIZE:
> + return pud_sect_supported();
> #endif
> case CONT_PMD_SIZE:
> case PMD_SIZE:
And here.
--
Catalin
next prev parent reply other threads:[~2021-09-16 16:31 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-09-15 3:44 [PATCH] arm64/mm: Add pud_sect_supported() Anshuman Khandual
2021-09-16 16:16 ` Catalin Marinas [this message]
2021-09-17 5:12 ` Anshuman Khandual
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