* [PATCH v9 04/32] powerpc: mm: add PMD swap-exclusive helpers
[not found] <20261105183940.2236717-1-usama.arif@linux.dev>
@ 2026-11-05 18:38 ` Usama Arif
0 siblings, 0 replies; only message in thread
From: Usama Arif @ 2026-11-05 18:38 UTC (permalink / raw)
To: Andrew Morton, david, chrisl, kasong, ljs, ziy, linux-mm
Cc: chenhuacai, ying.huang, Baoquan He, willy, youngjun.park, hannes,
riel, shakeel.butt, alex, kas, baohua, dev.jain, baolin.wang,
Nico Pache, Liam R. Howlett, ryan.roberts, Vlastimil Babka,
lance.yang, linux-kernel, nphamcs, shikemeng, yosry, qi.zheng,
luizcap, kernel-team, Usama Arif, Madhavan Srinivasan,
linuxppc-dev
Prepare for keeping a PMD-mapped anonymous THP mapped by a PMD across the
swap round-trip, which makes PG_anon_exclusive have to survive in a swap
PMD and not just in a swap PTE.
book3s64 builds a swap PMD by running the PTE encoding over pmd_pte(), so
the PMD helpers wrap the PTE ones and reuse _PAGE_SWP_EXCLUSIVE, exactly
as the soft-dirty PMD helpers next to them do. It is also the only powerpc
variant that selects ARCH_HAS_PMD_SOFTLEAVES, via PPC_THP.
Cc: Madhavan Srinivasan <maddy@linux.ibm.com>
Signed-off-by: Usama Arif <usama.arif@linux.dev>
Cc: linuxppc-dev@lists.ozlabs.org
---
arch/powerpc/include/asm/book3s/64/pgtable.h | 6 ++++++
1 file changed, 6 insertions(+)
diff --git a/arch/powerpc/include/asm/book3s/64/pgtable.h b/arch/powerpc/include/asm/book3s/64/pgtable.h
index dff8790a047db..458c85cebfa65 100644
--- a/arch/powerpc/include/asm/book3s/64/pgtable.h
+++ b/arch/powerpc/include/asm/book3s/64/pgtable.h
@@ -1060,6 +1060,12 @@ static inline pte_t *pmdp_ptep(pmd_t *pmd)
#endif
#endif /* CONFIG_HAVE_ARCH_SOFT_DIRTY */
+#ifdef CONFIG_ARCH_HAS_PMD_SOFTLEAVES
+#define pmd_swp_mkexclusive(pmd) pte_pmd(pte_swp_mkexclusive(pmd_pte(pmd)))
+#define pmd_swp_exclusive(pmd) pte_swp_exclusive(pmd_pte(pmd))
+#define pmd_swp_clear_exclusive(pmd) pte_pmd(pte_swp_clear_exclusive(pmd_pte(pmd)))
+#endif
+
#ifdef CONFIG_ARCH_HAS_PTE_PROTNONE
static inline int pmd_protnone(pmd_t pmd)
{
--
2.53.0-Meta
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