From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from foss.arm.com (foss.arm.com [217.140.110.172]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 846848834 for ; Fri, 29 May 2026 07:20:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=217.140.110.172 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780039237; cv=none; b=Ystt8siADMj07+JXfcLrT2x8pF6ORBPUOg3E9kfS9JDmieRVqDKkSOyRbE5e4UN8DjtoUu76wSnAnLE3k8/IYeAaJKSBmgVDg2wxJB0A4vFMBF4p2KTlXSh2xL/f4uq6dStYFFKnfxEdLbGknnLy3yXYzpeb3/7tHuuTgWvYnB4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1780039237; c=relaxed/simple; bh=UXmVe+6nihcUSdMk5zpoSuSsmXtK+I3VrEsEwpTBeAw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=XWroo/x2CBCRfKE1fruIqqVRbispSjnvXGekap28u8E0Jeo29YYST8ftwRa6410pc9UD5Uq4byeKeJXb1AGUGnR4gdmCkkNsfOpLO2GYYwIFhM/myahpDhATmb81k6WTIHQghmlmLuuLR5qIbQ8AoJZwNZ1nNC/4lDp7h3PrKYA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com; spf=pass smtp.mailfrom=arm.com; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b=RaEi4HbN; arc=none smtp.client-ip=217.140.110.172 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=arm.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=arm.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=arm.com header.i=@arm.com header.b="RaEi4HbN" Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 8376D2103; Fri, 29 May 2026 00:20:29 -0700 (PDT) Received: from [10.164.19.8] (unknown [10.164.19.8]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 9D58B3F905; Fri, 29 May 2026 00:20:26 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1780039234; bh=UXmVe+6nihcUSdMk5zpoSuSsmXtK+I3VrEsEwpTBeAw=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=RaEi4HbNto5D5Y4k/XQG1+TPoXISA4kzjvCCZXTwl8BPFUkxhhm063eAkWmEt+5YY S4bj1et7SkpzcU4X3C3/vQhvPJqGiOIkEslhPoyy/GfhMg7IMMQlr2hSKq2YdGG6Py 8lAbUjOU6FzvzHI1JM1GcnCVGG7/3dKZZMg3+Ero= Message-ID: <9341f4d1-329e-43a1-9c96-3e42207da803@arm.com> Date: Fri, 29 May 2026 12:50:23 +0530 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 01/13] mm: add softleaf_to_pmd() and convert existing callers To: Usama Arif , Andrew Morton , david@kernel.org, chrisl@kernel.org, kasong@tencent.com, ljs@kernel.org, ziy@nvidia.com Cc: bhe@redhat.com, willy@infradead.org, youngjun.park@lge.com, hannes@cmpxchg.org, riel@surriel.com, shakeel.butt@linux.dev, alex@ghiti.fr, kas@kernel.org, baohua@kernel.org, baolin.wang@linux.alibaba.com, npache@redhat.com, Liam.Howlett@oracle.com, ryan.roberts@arm.com, Vlastimil Babka , lance.yang@linux.dev, linux-kernel@vger.kernel.org, nphamcs@gmail.com, shikemeng@huaweicloud.com, kernel-team@meta.com References: <20260427100553.2754667-1-usama.arif@linux.dev> <20260427100553.2754667-2-usama.arif@linux.dev> Content-Language: en-US From: Dev Jain In-Reply-To: <20260427100553.2754667-2-usama.arif@linux.dev> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 27/04/26 3:31 pm, Usama Arif wrote: > Add softleaf_to_pmd() as the PMD counterpart to softleaf_to_pte(), > completing the symmetry of the softleaf abstraction for page table > leaf entries. > > The upcoming PMD swap entry support needs to construct PMD entries > from swap entries. Converting existing swp_entry_to_pmd() callers > to softleaf_to_pmd() in a prep patch keeps the feature patches > focused on new functionality rather than mixing refactoring with > new code. > > Signed-off-by: Usama Arif > --- Any reason why you have left out the conversion in migrate_device.c? > include/linux/leafops.h | 20 ++++++++++++++++++++ > mm/huge_memory.c | 12 ++++++------ > 2 files changed, 26 insertions(+), 6 deletions(-) > > diff --git a/include/linux/leafops.h b/include/linux/leafops.h > index 992cd8bd8ed0..803d312437df 100644 > --- a/include/linux/leafops.h > +++ b/include/linux/leafops.h > @@ -108,6 +108,21 @@ static inline softleaf_t softleaf_from_pmd(pmd_t pmd) > return swp_entry(__swp_type(arch_entry), __swp_offset(arch_entry)); > } > > +/** > + * softleaf_to_pmd() - Obtain a PMD entry from a leaf entry. > + * @entry: Leaf entry. > + * > + * This generates an architecture-specific PMD entry that can be utilised to > + * encode the metadata the leaf entry encodes. > + * > + * Returns: Architecture-specific PMD entry encoding leaf entry. > + */ > +static inline pmd_t softleaf_to_pmd(softleaf_t entry) > +{ > + /* Temporary until swp_entry_t eliminated. */ > + return swp_entry_to_pmd(entry); > +} > + > #else > > static inline softleaf_t softleaf_from_pmd(pmd_t pmd) > @@ -115,6 +130,11 @@ static inline softleaf_t softleaf_from_pmd(pmd_t pmd) > return softleaf_mk_none(); > } > > +static inline pmd_t softleaf_to_pmd(softleaf_t entry) > +{ > + return __pmd(0); > +} > + > #endif > > /** > diff --git a/mm/huge_memory.c b/mm/huge_memory.c > index 970e077019b7..49da0746b8ca 100644 > --- a/mm/huge_memory.c > +++ b/mm/huge_memory.c > @@ -1881,7 +1881,7 @@ static void copy_huge_non_present_pmd( > if (softleaf_is_migration_write(entry) || > softleaf_is_migration_read_exclusive(entry)) { > entry = make_readable_migration_entry(swp_offset(entry)); > - pmd = swp_entry_to_pmd(entry); > + pmd = softleaf_to_pmd(entry); > if (pmd_swp_soft_dirty(*src_pmd)) > pmd = pmd_swp_mksoft_dirty(pmd); > if (pmd_swp_uffd_wp(*src_pmd)) > @@ -1894,7 +1894,7 @@ static void copy_huge_non_present_pmd( > */ > if (softleaf_is_device_private_write(entry)) { > entry = make_readable_device_private_entry(swp_offset(entry)); > - pmd = swp_entry_to_pmd(entry); > + pmd = softleaf_to_pmd(entry); > > if (pmd_swp_soft_dirty(*src_pmd)) > pmd = pmd_swp_mksoft_dirty(pmd); > @@ -2632,12 +2632,12 @@ static void change_non_present_huge_pmd(struct mm_struct *mm, > entry = make_readable_exclusive_migration_entry(swp_offset(entry)); > else > entry = make_readable_migration_entry(swp_offset(entry)); > - newpmd = swp_entry_to_pmd(entry); > + newpmd = softleaf_to_pmd(entry); > if (pmd_swp_soft_dirty(*pmd)) > newpmd = pmd_swp_mksoft_dirty(newpmd); > } else if (softleaf_is_device_private_write(entry)) { > entry = make_readable_device_private_entry(swp_offset(entry)); > - newpmd = swp_entry_to_pmd(entry); > + newpmd = softleaf_to_pmd(entry); > } else { > newpmd = *pmd; > } > @@ -5014,7 +5014,7 @@ int set_pmd_migration_entry(struct page_vma_mapped_walk *pvmw, > entry = make_migration_entry_young(entry); > if (pmd_dirty(pmdval)) > entry = make_migration_entry_dirty(entry); > - pmdswp = swp_entry_to_pmd(entry); > + pmdswp = softleaf_to_pmd(entry); > if (pmd_soft_dirty(pmdval)) > pmdswp = pmd_swp_mksoft_dirty(pmdswp); > if (pmd_uffd_wp(pmdval)) > @@ -5065,7 +5065,7 @@ void remove_migration_pmd(struct page_vma_mapped_walk *pvmw, struct page *new) > else > entry = make_readable_device_private_entry( > page_to_pfn(new)); > - pmde = swp_entry_to_pmd(entry); > + pmde = softleaf_to_pmd(entry); > > if (pmd_swp_soft_dirty(*pvmw->pmd)) > pmde = pmd_swp_mksoft_dirty(pmde);