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Date: Wed, 7 Oct 2026 11:41:41 +0200
From: Nathan Chancellor <nathan@kernel.org>
To: Rosen Penev <rosenp@gmail.com>
Cc: Kjetil Oftedal <oftedal@gmail.com>, sparclinux@vger.kernel.org,
	"David S. Miller" <davem@davemloft.net>,
	Andreas Larsson <andreas@gaisler.com>,
	Nick Desaulniers <ndesaulniers@google.com>,
	Bill Wendling <morbo@google.com>,
	Justin Stitt <justinstitt@google.com>,
	open list <linux-kernel@vger.kernel.org>,
	"open list:CLANG/LLVM BUILD SUPPORT:Keyword:b(?i:clang|llvm)b" <llvm@lists.linux.dev>
Subject: Re: [PATCH] sparc64: Define p4d_page() instead of stubbing it to NULL
Message-ID: <20261007094141.GA1527675@ax162>
References: <20261005203930.246598-1-rosenp@gmail.com>
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 <20261006083103.GA3041473@ax162>
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On Tue, Oct 06, 2026 at 05:00:30PM -0700, Rosen Penev wrote:
> LLM suggests as an alternative:
> 
> /* sparc64 has no p4d leaf mappings, so this is never called */
> static inline struct page *p4d_page(p4d_t p4d)
> {
>       return NULL;
> }
> 
> Not sure how to proceed.

That seems like a more reasonable fix to me, as it is still obvious this
is not supported while hiding the NULL value from clang's frontend that
emits the warning. It could be worth a comment that it is an inline
function and not a macro to avoid the warning but I guess that is up to
the sparc maintainers.

-- 
Cheers,
Nathan