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Date:   Tue, 1 Aug 2023 12:09:47 +0100
From:   Catalin Marinas <catalin.marinas@arm.com>
To:     Kefeng Wang <wangkefeng.wang@huawei.com>
Cc:     Andrew Morton <akpm@linux-foundation.org>,
        Will Deacon <will@kernel.org>,
        Mike Kravetz <mike.kravetz@oracle.com>,
        Muchun Song <muchun.song@linux.dev>,
        Mina Almasry <almasrymina@google.com>, kirill@shutemov.name,
        joel@joelfernandes.org, william.kucharski@oracle.com,
        kaleshsingh@google.com, linux-mm@kvack.org,
        linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org,
        21cnbao@gmail.com
Subject: Re: [PATCH v2 2/2] arm64: hugetlb: enable
 __HAVE_ARCH_FLUSH_HUGETLB_TLB_RANGE
Message-ID: <ZMjn+68gKrdQSjMD@arm.com>
References: <20230801023145.17026-1-wangkefeng.wang@huawei.com>
 <20230801023145.17026-3-wangkefeng.wang@huawei.com>
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On Tue, Aug 01, 2023 at 10:31:45AM +0800, Kefeng Wang wrote:
> +#define __HAVE_ARCH_FLUSH_HUGETLB_TLB_RANGE
> +static inline void flush_hugetlb_tlb_range(struct vm_area_struct *vma,
> +					   unsigned long start,
> +					   unsigned long end)
> +{
> +	unsigned long stride = huge_page_size(hstate_vma(vma));
> +
> +	if (stride != PMD_SIZE && stride != PUD_SIZE)
> +		stride = PAGE_SIZE;
> +	__flush_tlb_range(vma, start, end, stride, false, 0);

We could use some hints here for the tlb_level (2 for pmd, 1 for pud).
Regarding the last_level argument to __flush_tlb_range(), I think it
needs to stay false since this function is also called on the
hugetlb_unshare_pmds() path where the pud is cleared and needs
invalidating.

That said, maybe you can rewrite it as a switch statement and call
flush_pmd_tlb_range() or flush_pud_tlb_range() (just make sure these are
defined when CONFIG_HUGETLBFS is enabled).

-- 
Catalin