From: Anshuman Khandual <anshuman.khandual@arm.com>
To: Will Deacon <will@kernel.org>
Cc: linux-arm-kernel@lists.infradead.org, ryan.roberts@arm.com,
Catalin Marinas <catalin.marinas@arm.com>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] arm64/mm: Add a fallback stub for pgd_page_paddr()
Date: Thu, 6 Nov 2025 07:29:55 +0530 [thread overview]
Message-ID: <044a6526-d6e8-4ae0-9279-8cc42bff5aa0@arm.com> (raw)
In-Reply-To: <aQuDdE_Tj3di7q3P@willie-the-truck>
On 05/11/25 10:33 PM, Will Deacon wrote:
> On Wed, Nov 05, 2025 at 08:24:40AM +0530, Anshuman Khandual wrote:
>> On 04/11/25 8:01 PM, Will Deacon wrote:
>>> On Tue, Oct 14, 2025 at 12:06:33PM +0100, Anshuman Khandual wrote:
>>>> Add a fallback stub for pgd_page_paddr() when (PGTBALE_LEVELS <= 4) which
>>>
>>> typo
>>
>> Sure will change - s/Add/Adds
>>>
>>>> helps in intercepting any unintended usage and which is also in line with
>>>> existing stubs for similar [pud|p4d]_page_paddr() helpers.
>>>
>>> Are you saying the kernel compiles in this case without your patch? Which
>>> definition of pgd_page_paddr() does it end up using?
>>
>> Kernel compiles for PGTBALE_LEVELS <= 4 just fine without this patch as both
>> its current users p4d_offset_phys() and p4d_offset_lockless() are wrapped in
>> with PGTBALE_LEVELS > 4.
>
> Ok, but your patch is trying to catch broken users of the macro, right?
Right but there are no broken users at present because all the users are
wrapped inside #ifdef PGTBALE_LEVELS > 4.
> So my question is, would such a user compile today? If not, then your
> patch is pointless.
The point is this macro is not visible outside #ifdef PGTBALE_LEVELS > 4
where as similar ones such as p4d_page_paddr() and pud_page_paddr() are
always visible via their respective fallback stubs, when PGTABLE_LEVELS
are lower.
next prev parent reply other threads:[~2025-11-06 2:00 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-14 11:06 Anshuman Khandual
2025-11-04 14:31 ` Will Deacon
2025-11-05 2:54 ` Anshuman Khandual
2025-11-05 17:03 ` Will Deacon
2025-11-06 1:59 ` Anshuman Khandual [this message]
2025-11-13 16:19 ` Catalin Marinas
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=044a6526-d6e8-4ae0-9279-8cc42bff5aa0@arm.com \
--to=anshuman.khandual@arm.com \
--cc=catalin.marinas@arm.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=ryan.roberts@arm.com \
--cc=will@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox
all inboxes | Powered by JetHome®