mm/page_alloc: add support for initializing pageblock as isolated

MIGRATE_ISOLATE is a standalone bit, so a pageblock cannot be initialized
to just MIGRATE_ISOLATE.  Add init_pageblock_migratetype() to enable
initialize a pageblock with a migratetype and isolated.

Link: https://lkml.kernel.org/r/20250617021115.2331563-4-ziy@nvidia.com
Signed-off-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: David Hildenbrand <david@redhat.com>
Cc: Baolin Wang <baolin.wang@linux.alibaba.com>
Cc: Brendan Jackman <jackmanb@google.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Kirill A. Shuemov <kirill.shutemov@linux.intel.com>
Cc: Mel Gorman <mgorman@techsingularity.net>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Oscar Salvador <osalvador@suse.de>
Cc: Richard Chang <richardycc@google.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

include/linux/memory_hotplug.h

@@ -314,7 +314,8 @@ extern int add_memory_driver_managed(int nid, u64 start, u64 size,
 				     mhp_t mhp_flags);
 extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
 				   unsigned long nr_pages,
-				   struct vmem_altmap *altmap, int migratetype);
+				   struct vmem_altmap *altmap, int migratetype,
+				   bool isolate_pageblock);
 extern void remove_pfn_range_from_zone(struct zone *zone,
 				       unsigned long start_pfn,
 				       unsigned long nr_pages);

include/linux/page-isolation.h

@@ -41,6 +41,9 @@ static inline void set_pageblock_isolate(struct page *page)
 #define MEMORY_OFFLINE	0x1
 #define REPORT_FAILURE	0x2
 
+void __meminit init_pageblock_migratetype(struct page *page,
+					  enum migratetype migratetype,
+					  bool isolate);
 void set_pageblock_migratetype(struct page *page, enum migratetype migratetype);
 
 bool move_freepages_block_isolate(struct zone *zone, struct page *page,

kernel/kexec_handover.c

@@ -1100,8 +1100,8 @@ static void __init kho_release_scratch(void)
 		ulong pfn;
 
 		for (pfn = start_pfn; pfn < end_pfn; pfn += pageblock_nr_pages)
-			set_pageblock_migratetype(pfn_to_page(pfn),
+			init_pageblock_migratetype(pfn_to_page(pfn),
-						  MIGRATE_CMA);
+						   MIGRATE_CMA, false);
 	}
 }
 

mm/hugetlb.c

@@ -3297,8 +3297,8 @@ static void __init hugetlb_bootmem_init_migratetype(struct folio *folio,
 		if (folio_test_hugetlb_cma(folio))
 			init_cma_pageblock(folio_page(folio, i));
 		else
-			set_pageblock_migratetype(folio_page(folio, i),
+			init_pageblock_migratetype(folio_page(folio, i),
-					  MIGRATE_MOVABLE);
+					  MIGRATE_MOVABLE, false);
 	}
 }
 

mm/internal.h

@@ -820,7 +820,8 @@ extern void *memmap_alloc(phys_addr_t size, phys_addr_t align,
 			  int nid, bool exact_nid);
 
 void memmap_init_range(unsigned long, int, unsigned long, unsigned long,
-		unsigned long, enum meminit_context, struct vmem_altmap *, int);
+		unsigned long, enum meminit_context, struct vmem_altmap *, int,
+		bool);
 
 #if defined CONFIG_COMPACTION || defined CONFIG_CMA
 

mm/memory_hotplug.c

@@ -747,7 +747,8 @@ static inline void section_taint_zone_device(unsigned long pfn)
  */
 void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
 				  unsigned long nr_pages,
-				  struct vmem_altmap *altmap, int migratetype)
+				  struct vmem_altmap *altmap, int migratetype,
+				  bool isolate_pageblock)
 {
 	struct pglist_data *pgdat = zone->zone_pgdat;
 	int nid = pgdat->node_id;
@@ -779,7 +780,8 @@ void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
 	 * are reserved so nobody should be touching them so we should be safe
 	 */
 	memmap_init_range(nr_pages, nid, zone_idx(zone), start_pfn, 0,
-			 MEMINIT_HOTPLUG, altmap, migratetype);
+			 MEMINIT_HOTPLUG, altmap, migratetype,
+			 isolate_pageblock);
 
 	set_zone_contiguous(zone);
 }
@@ -1104,7 +1106,8 @@ int mhp_init_memmap_on_memory(unsigned long pfn, unsigned long nr_pages,
 	if (mhp_off_inaccessible)
 		page_init_poison(pfn_to_page(pfn), sizeof(struct page) * nr_pages);
 
-	move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_UNMOVABLE);
+	move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_UNMOVABLE,
+			       false);
 
 	for (i = 0; i < nr_pages; i++) {
 		struct page *page = pfn_to_page(pfn + i);
@@ -1175,7 +1178,8 @@ int online_pages(unsigned long pfn, unsigned long nr_pages,
 
 
 	/* associate pfn range with the zone */
-	move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_ISOLATE);
+	move_pfn_range_to_zone(zone, pfn, nr_pages, NULL, MIGRATE_MOVABLE,
+			       true);
 
 	if (!node_state(nid, N_MEMORY)) {
 		/* Adding memory to the node for the first time */

mm/memremap.c

@@ -228,7 +228,7 @@ static int pagemap_range(struct dev_pagemap *pgmap, struct mhp_params *params,
 		zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
 		move_pfn_range_to_zone(zone, PHYS_PFN(range->start),
 				PHYS_PFN(range_len(range)), params->altmap,
-				MIGRATE_MOVABLE);
+				MIGRATE_MOVABLE, false);
 	}
 
 	mem_hotplug_done();

mm/mm_init.c

@@ -685,7 +685,8 @@ void __meminit __init_page_from_nid(unsigned long pfn, int nid)
 	__init_single_page(pfn_to_page(pfn), pfn, zid, nid);
 
 	if (pageblock_aligned(pfn))
-		set_pageblock_migratetype(pfn_to_page(pfn), MIGRATE_MOVABLE);
+		init_pageblock_migratetype(pfn_to_page(pfn), MIGRATE_MOVABLE,
+				false);
 }
 
 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
@@ -874,7 +875,8 @@ static void __init init_unavailable_range(unsigned long spfn,
 void __meminit memmap_init_range(unsigned long size, int nid, unsigned long zone,
 		unsigned long start_pfn, unsigned long zone_end_pfn,
 		enum meminit_context context,
-		struct vmem_altmap *altmap, int migratetype)
+		struct vmem_altmap *altmap, int migratetype,
+		bool isolate_pageblock)
 {
 	unsigned long pfn, end_pfn = start_pfn + size;
 	struct page *page;
@@ -931,7 +933,8 @@ void __meminit memmap_init_range(unsigned long size, int nid, unsigned long zone
 		 * over the place during system boot.
 		 */
 		if (pageblock_aligned(pfn)) {
-			set_pageblock_migratetype(page, migratetype);
+			init_pageblock_migratetype(page, migratetype,
+					isolate_pageblock);
 			cond_resched();
 		}
 		pfn++;
@@ -954,7 +957,8 @@ static void __init memmap_init_zone_range(struct zone *zone,
 		return;
 
 	memmap_init_range(end_pfn - start_pfn, nid, zone_id, start_pfn,
-			  zone_end_pfn, MEMINIT_EARLY, NULL, MIGRATE_MOVABLE);
+			  zone_end_pfn, MEMINIT_EARLY, NULL, MIGRATE_MOVABLE,
+			  false);
 
 	if (*hole_pfn < start_pfn)
 		init_unavailable_range(*hole_pfn, start_pfn, zone_id, nid);
@@ -1035,7 +1039,7 @@ static void __ref __init_zone_device_page(struct page *page, unsigned long pfn,
 	 * because this is done early in section_activate()
 	 */
 	if (pageblock_aligned(pfn)) {
-		set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+		init_pageblock_migratetype(page, MIGRATE_MOVABLE, false);
 		cond_resched();
 	}
 
@@ -1996,7 +2000,8 @@ static void __init deferred_free_pages(unsigned long pfn,
 	/* Free a large naturally-aligned chunk if possible */
 	if (nr_pages == MAX_ORDER_NR_PAGES && IS_MAX_ORDER_ALIGNED(pfn)) {
 		for (i = 0; i < nr_pages; i += pageblock_nr_pages)
-			set_pageblock_migratetype(page + i, MIGRATE_MOVABLE);
+			init_pageblock_migratetype(page + i, MIGRATE_MOVABLE,
+					false);
 		__free_pages_core(page, MAX_PAGE_ORDER, MEMINIT_EARLY);
 		return;
 	}
@@ -2006,7 +2011,8 @@ static void __init deferred_free_pages(unsigned long pfn,
 
 	for (i = 0; i < nr_pages; i++, page++, pfn++) {
 		if (pageblock_aligned(pfn))
-			set_pageblock_migratetype(page, MIGRATE_MOVABLE);
+			init_pageblock_migratetype(page, MIGRATE_MOVABLE,
+					false);
 		__free_pages_core(page, 0, MEMINIT_EARLY);
 	}
 }
@@ -2305,7 +2311,7 @@ void __init init_cma_reserved_pageblock(struct page *page)
 		set_page_count(p, 0);
 	} while (++p, --i);
 
-	set_pageblock_migratetype(page, MIGRATE_CMA);
+	init_pageblock_migratetype(page, MIGRATE_CMA, false);
 	set_page_refcounted(page);
 	/* pages were reserved and not allocated */
 	clear_page_tag_ref(page);
@@ -2319,7 +2325,7 @@ void __init init_cma_reserved_pageblock(struct page *page)
  */
 void __init init_cma_pageblock(struct page *page)
 {
-	set_pageblock_migratetype(page, MIGRATE_CMA);
+	init_pageblock_migratetype(page, MIGRATE_CMA, false);
 	adjust_managed_page_count(page, pageblock_nr_pages);
 	page_zone(page)->cma_pages += pageblock_nr_pages;
 }

mm/page_alloc.c

@@ -544,6 +544,32 @@ __always_inline void set_pageblock_migratetype(struct page *page,
 				  MIGRATETYPE_AND_ISO_MASK);
 }
 
+void __meminit init_pageblock_migratetype(struct page *page,
+					  enum migratetype migratetype,
+					  bool isolate)
+{
+	unsigned long flags;
+
+	if (unlikely(page_group_by_mobility_disabled &&
+		     migratetype < MIGRATE_PCPTYPES))
+		migratetype = MIGRATE_UNMOVABLE;
+
+	flags = migratetype;
+
+#ifdef CONFIG_MEMORY_ISOLATION
+	if (migratetype == MIGRATE_ISOLATE) {
+		VM_WARN_ONCE(
+			1,
+			"Set isolate=true to isolate pageblock with a migratetype");
+		return;
+	}
+	if (isolate)
+		flags |= BIT(PB_migrate_isolate);
+#endif
+	__set_pfnblock_flags_mask(page, page_to_pfn(page), flags,
+				  MIGRATETYPE_AND_ISO_MASK);
+}
+
 #ifdef CONFIG_DEBUG_VM
 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
 {