mm/damon: move folio filtering from paddr to ops-common

This patch moves damos_pa_filter_match and the functions it calls to
ops-common, renaming it to damos_folio_filter_match.  Doing so allows us
to share the filtering logic for the vaddr version of the
migrate_{hot,cold} schemes.

Link: https://lkml.kernel.org/r/20250709005952.17776-13-bijan311@gmail.com
Co-developed-by: Ravi Shankar Jonnalagadda <ravis.opensrc@micron.com>
Signed-off-by: Ravi Shankar Jonnalagadda <ravis.opensrc@micron.com>
Signed-off-by: Bijan Tabatabai <bijantabatab@micron.com>
Reviewed-by: SeongJae Park <sj@kernel.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

1 files changed, 150 insertions, 0 deletions

diff --git a/mm/damon/ops-common.c b/mm/damon/ops-common.c
index 918158ef3d99..6a9797d1d7ff 100644
--- a/mm/damon/ops-common.c
+++ b/mm/damon/ops-common.c
@@ -141,6 +141,156 @@ int damon_cold_score(struct damon_ctx *c, struct damon_region *r,
 	return DAMOS_MAX_SCORE - hotness;
 }
 
+static bool damon_folio_mkold_one(struct folio *folio,
+		struct vm_area_struct *vma, unsigned long addr, void *arg)
+{
+	DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, addr, 0);
+
+	while (page_vma_mapped_walk(&pvmw)) {
+		addr = pvmw.address;
+		if (pvmw.pte)
+			damon_ptep_mkold(pvmw.pte, vma, addr);
+		else
+			damon_pmdp_mkold(pvmw.pmd, vma, addr);
+	}
+	return true;
+}
+
+void damon_folio_mkold(struct folio *folio)
+{
+	struct rmap_walk_control rwc = {
+		.rmap_one = damon_folio_mkold_one,
+		.anon_lock = folio_lock_anon_vma_read,
+	};
+	bool need_lock;
+
+	if (!folio_mapped(folio) || !folio_raw_mapping(folio)) {
+		folio_set_idle(folio);
+		return;
+	}
+
+	need_lock = !folio_test_anon(folio) || folio_test_ksm(folio);
+	if (need_lock && !folio_trylock(folio))
+		return;
+
+	rmap_walk(folio, &rwc);
+
+	if (need_lock)
+		folio_unlock(folio);
+
+}
+
+static bool damon_folio_young_one(struct folio *folio,
+		struct vm_area_struct *vma, unsigned long addr, void *arg)
+{
+	bool *accessed = arg;
+	DEFINE_FOLIO_VMA_WALK(pvmw, folio, vma, addr, 0);
+	pte_t pte;
+
+	*accessed = false;
+	while (page_vma_mapped_walk(&pvmw)) {
+		addr = pvmw.address;
+		if (pvmw.pte) {
+			pte = ptep_get(pvmw.pte);
+
+			/*
+			 * PFN swap PTEs, such as device-exclusive ones, that
+			 * actually map pages are "old" from a CPU perspective.
+			 * The MMU notifier takes care of any device aspects.
+			 */
+			*accessed = (pte_present(pte) && pte_young(pte)) ||
+				!folio_test_idle(folio) ||
+				mmu_notifier_test_young(vma->vm_mm, addr);
+		} else {
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+			*accessed = pmd_young(pmdp_get(pvmw.pmd)) ||
+				!folio_test_idle(folio) ||
+				mmu_notifier_test_young(vma->vm_mm, addr);
+#else
+			WARN_ON_ONCE(1);
+#endif	/* CONFIG_TRANSPARENT_HUGEPAGE */
+		}
+		if (*accessed) {
+			page_vma_mapped_walk_done(&pvmw);
+			break;
+		}
+	}
+
+	/* If accessed, stop walking */
+	return *accessed == false;
+}
+
+bool damon_folio_young(struct folio *folio)
+{
+	bool accessed = false;
+	struct rmap_walk_control rwc = {
+		.arg = &accessed,
+		.rmap_one = damon_folio_young_one,
+		.anon_lock = folio_lock_anon_vma_read,
+	};
+	bool need_lock;
+
+	if (!folio_mapped(folio) || !folio_raw_mapping(folio)) {
+		if (folio_test_idle(folio))
+			return false;
+		else
+			return true;
+	}
+
+	need_lock = !folio_test_anon(folio) || folio_test_ksm(folio);
+	if (need_lock && !folio_trylock(folio))
+		return false;
+
+	rmap_walk(folio, &rwc);
+
+	if (need_lock)
+		folio_unlock(folio);
+
+	return accessed;
+}
+
+bool damos_folio_filter_match(struct damos_filter *filter, struct folio *folio)
+{
+	bool matched = false;
+	struct mem_cgroup *memcg;
+	size_t folio_sz;
+
+	switch (filter->type) {
+	case DAMOS_FILTER_TYPE_ANON:
+		matched = folio_test_anon(folio);
+		break;
+	case DAMOS_FILTER_TYPE_ACTIVE:
+		matched = folio_test_active(folio);
+		break;
+	case DAMOS_FILTER_TYPE_MEMCG:
+		rcu_read_lock();
+		memcg = folio_memcg_check(folio);
+		if (!memcg)
+			matched = false;
+		else
+			matched = filter->memcg_id == mem_cgroup_id(memcg);
+		rcu_read_unlock();
+		break;
+	case DAMOS_FILTER_TYPE_YOUNG:
+		matched = damon_folio_young(folio);
+		if (matched)
+			damon_folio_mkold(folio);
+		break;
+	case DAMOS_FILTER_TYPE_HUGEPAGE_SIZE:
+		folio_sz = folio_size(folio);
+		matched = filter->sz_range.min <= folio_sz &&
+			  folio_sz <= filter->sz_range.max;
+		break;
+	case DAMOS_FILTER_TYPE_UNMAPPED:
+		matched = !folio_mapped(folio) || !folio_raw_mapping(folio);
+		break;
+	default:
+		break;
+	}
+
+	return matched == filter->matching;
+}
+
 static unsigned int __damon_migrate_folio_list(
 		struct list_head *migrate_folios, struct pglist_data *pgdat,
 		int target_nid)