From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To: stable@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	patches@lists.linux.dev,
	Andy Shevchenko <andriy.shevchenko@linux.intel.com>,
	Leon Romanovsky <leonro@nvidia.com>,
	Alistair Popple <apopple@nvidia.com>,
	Bill Wendling <morbo@google.com>,
	Jerome Glisse <jglisse@redhat.com>,
	Justin Stitt <justinstitt@google.com>,
	Nathan Chancellor <nathan@kernel.org>,
	Andrew Morton <akpm@linux-foundation.org>
Subject: [PATCH 6.1 252/253] mm/hmm: move pmd_to_hmm_pfn_flags() to the respective #ifdeffery
Date: Tue, 12 Aug 2025 19:30:40 +0200
Message-ID: <20250812172959.588969467@linuxfoundation.org>
In-Reply-To: <20250812172948.675299901@linuxfoundation.org>
References: <20250812172948.675299901@linuxfoundation.org>
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6.1-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>

commit 188cb385bbf04d486df3e52f28c47b3961f5f0c0 upstream.

When pmd_to_hmm_pfn_flags() is unused, it prevents kernel builds with
clang, `make W=1` and CONFIG_TRANSPARENT_HUGEPAGE=n:

  mm/hmm.c:186:29: warning: unused function 'pmd_to_hmm_pfn_flags' [-Wunused-function]

Fix this by moving the function to the respective existing ifdeffery
for its the only user.

See also:

  6863f5643dd7 ("kbuild: allow Clang to find unused static inline functions for W=1 build")

Link: https://lkml.kernel.org/r/20250710082403.664093-1-andriy.shevchenko@linux.intel.com
Fixes: 992de9a8b751 ("mm/hmm: allow to mirror vma of a file on a DAX backed filesystem")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Leon Romanovsky <leonro@nvidia.com>
Reviewed-by: Alistair Popple <apopple@nvidia.com>
Cc: Andriy Shevchenko <andriy.shevchenko@linux.intel.com>
Cc: Bill Wendling <morbo@google.com>
Cc: Jerome Glisse <jglisse@redhat.com>
Cc: Justin Stitt <justinstitt@google.com>
Cc: Nathan Chancellor <nathan@kernel.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
 mm/hmm.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/hmm.c
+++ b/mm/hmm.c
@@ -173,6 +173,7 @@ static inline unsigned long hmm_pfn_flag
 	return order << HMM_PFN_ORDER_SHIFT;
 }
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 static inline unsigned long pmd_to_hmm_pfn_flags(struct hmm_range *range,
 						 pmd_t pmd)
 {
@@ -183,7 +184,6 @@ static inline unsigned long pmd_to_hmm_p
 	       hmm_pfn_flags_order(PMD_SHIFT - PAGE_SHIFT);
 }
 
-#ifdef CONFIG_TRANSPARENT_HUGEPAGE
 static int hmm_vma_handle_pmd(struct mm_walk *walk, unsigned long addr,
 			      unsigned long end, unsigned long hmm_pfns[],
 			      pmd_t pmd)