linux-kernel - Re: [PATCH v3 04/11] arm64/mm: Refactor __set_ptes() and __ptep_get_and

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Message-ID: <Z_023iswKD9NO3uH@arm.com>
Date: Mon, 14 Apr 2025 17:25:02 +0100
From: Catalin Marinas <catalin.marinas@....com>
To: Ryan Roberts <ryan.roberts@....com>
Cc: Will Deacon <will@...nel.org>,
	Pasha Tatashin <pasha.tatashin@...een.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Uladzislau Rezki <urezki@...il.com>,
	Christoph Hellwig <hch@...radead.org>,
	David Hildenbrand <david@...hat.com>,
	"Matthew Wilcox (Oracle)" <willy@...radead.org>,
	Mark Rutland <mark.rutland@....com>,
	Anshuman Khandual <anshuman.khandual@....com>,
	Alexandre Ghiti <alexghiti@...osinc.com>,
	Kevin Brodsky <kevin.brodsky@....com>,
	linux-arm-kernel@...ts.infradead.org, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH v3 04/11] arm64/mm: Refactor __set_ptes() and
 __ptep_get_and_clear()

On Tue, Mar 04, 2025 at 03:04:34PM +0000, Ryan Roberts wrote:
> +static inline void set_ptes_anysz(struct mm_struct *mm, pte_t *ptep, pte_t pte,
> +				  unsigned int nr, unsigned long pgsize)
>  {
> -	__sync_cache_and_tags(pte, nr);
> -	__check_safe_pte_update(mm, ptep, pte);
> -	__set_pte(ptep, pte);
> +	unsigned long stride = pgsize >> PAGE_SHIFT;
> +
> +	switch (pgsize) {
> +	case PAGE_SIZE:
> +		page_table_check_ptes_set(mm, ptep, pte, nr);
> +		break;
> +	case PMD_SIZE:
> +		page_table_check_pmds_set(mm, (pmd_t *)ptep, pte_pmd(pte), nr);
> +		break;
> +	case PUD_SIZE:
> +		page_table_check_puds_set(mm, (pud_t *)ptep, pte_pud(pte), nr);
> +		break;
> +	default:
> +		VM_WARN_ON(1);
> +	}
> +
> +	__sync_cache_and_tags(pte, nr * stride);
> +
> +	for (;;) {
> +		__check_safe_pte_update(mm, ptep, pte);
> +		__set_pte(ptep, pte);
> +		if (--nr == 0)
> +			break;
> +		ptep++;
> +		pte = pte_advance_pfn(pte, stride);
> +	}
>  }

I thought I replied to this one but somehow failed to send. The only
comment I have is that I'd add a double underscore in front of the anysz
functions to imply it's a private API. Otherwise it looks fine.

Reviewed-by: Catalin Marinas <catalin.marinas@....com>