From 2492d9c0afc02cebe8318155829e7d03bea617b8 Mon Sep 17 00:00:00 2001
From: Kaitao Cheng <chengkaitao@kylinos.cn>
Date: Thu, 3 Sep 2026 13:35:34 +0800
Subject: [PATCH] mm/page-flags: define HWPoison test-and-change helpers
 unconditionally

Page flag helpers for configuration-dependent flags provide false or no-op
variants so that their users can be independent of the configuration.

The HWPoison helpers do not fully follow this pattern.  When
CONFIG_MEMORY_FAILURE is enabled, PAGEFLAG() and TESTSCFLAG() provide the
regular, test-and-set, and test-and-clear operations.  When it is
disabled, only PAGEFLAG_FALSE() is instantiated, leaving
TestSetPageHWPoison() and TestClearPageHWPoison() undefined.

Use TESTSCFLAG_FALSE() to provide the missing accessors when memory
failure handling is disabled.  Both accessors return false, which is
consistent with HWPoison state being unavailable, and makes the accessor
interface consistent across configurations.

Also remove now-unneeded test_and_clear_pmem_poison() from nvdimm/pmem.

Link: https://lore.kernel.org/20260903053535.17611-1-kaitao.cheng@linux.dev
Link: https://lore.kernel.org/20260903053535.17611-2-kaitao.cheng@linux.dev
Link: https://lore.kernel.org/20260903053535.17611-3-kaitao.cheng@linux.dev
Signed-off-by: Kaitao Cheng <chengkaitao@kylinos.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Muchun Song <muchun.song@linux.dev>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Oscar Salvador <osalvador@suse.de>
Cc: Alison Schofield <alison.schofield@intel.com>
Cc: Dave Jiang <dave.jiang@intel.com>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Lorenzo Stoakes <ljs@kernel.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Mike Rapoport <rppt@kernel.org>
Cc: Suren Baghdasaryan <surenb@google.com>
Cc: Vishal Verma <vishal.l.verma@intel.com>
Cc: Vlastimil Babka <vbabka@kernel.org>
Cc: Ira Weiny <iweiny@kernel.org>
---
 drivers/nvdimm/pmem.c      |  2 +-
 drivers/nvdimm/pmem.h      | 12 ------------
 include/linux/page-flags.h |  1 +
 3 files changed, 2 insertions(+), 13 deletions(-)

diff --git a/drivers/nvdimm/pmem.c b/drivers/nvdimm/pmem.c
index 30a51c365ce8..5fb86595e8bd 100644
--- a/drivers/nvdimm/pmem.c
+++ b/drivers/nvdimm/pmem.c
@@ -80,7 +80,7 @@ static void pmem_mkpage_present(struct pmem_device *pmem, phys_addr_t offset,
 		 * here since we're in the driver I/O path and
 		 * outstanding I/O requests pin the dev_pagemap.
 		 */
-		if (test_and_clear_pmem_poison(page))
+		if (TestClearPageHWPoison(page))
 			clear_mce_nospec(pfn);
 	}
 }
diff --git a/drivers/nvdimm/pmem.h b/drivers/nvdimm/pmem.h
index a48509f90196..76870505dd79 100644
--- a/drivers/nvdimm/pmem.h
+++ b/drivers/nvdimm/pmem.h
@@ -1,7 +1,6 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef __NVDIMM_PMEM_H__
 #define __NVDIMM_PMEM_H__
-#include <linux/page-flags.h>
 #include <linux/badblocks.h>
 #include <linux/memremap.h>
 #include <linux/types.h>
@@ -31,15 +30,4 @@ long __pmem_direct_access(struct pmem_device *pmem, pgoff_t pgoff,
 		long nr_pages, enum dax_access_mode mode, void **kaddr,
 		unsigned long *pfn);
 
-#ifdef CONFIG_MEMORY_FAILURE
-static inline bool test_and_clear_pmem_poison(struct page *page)
-{
-	return TestClearPageHWPoison(page);
-}
-#else
-static inline bool test_and_clear_pmem_poison(struct page *page)
-{
-	return false;
-}
-#endif
 #endif /* __NVDIMM_PMEM_H__ */
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index ae2ebaed6d4d..3dc79c0c5adf 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -655,6 +655,7 @@ TESTSCFLAG(HWPoison, hwpoison, PF_ANY)
 #define __PG_HWPOISON (1UL << PG_hwpoison)
 #else
 PAGEFLAG_FALSE(HWPoison, hwpoison)
+TESTSCFLAG_FALSE(HWPoison, hwpoison)
 #define __PG_HWPOISON 0
 #endif