[PATCH 01/13] mm: Plumb dev_pagemap instead of vmem_altmap to memmap_init_zone()

[Dan Williams <dan.j.williams@xxxxxxxxx>]

In preparation for teaching memmap_init_zone() how to initialize
ZONE_DEVICE pages, pass in dev_pagemap.

Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Dan Williams <dan.j.williams@xxxxxxxxx>
---
 include/linux/memory_hotplug.h |    3 ++-
 include/linux/mm.h             |    2 +-
 kernel/memremap.c              |    2 +-
 mm/memory_hotplug.c            |    4 ++--
 mm/page_alloc.c                |    5 ++++-
 5 files changed, 10 insertions(+), 6 deletions(-)

diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h
index 4e9828cda7a2..e60085b2824d 100644
--- a/include/linux/memory_hotplug.h
+++ b/include/linux/memory_hotplug.h
@@ -14,6 +14,7 @@ struct mem_section;
 struct memory_block;
 struct resource;
 struct vmem_altmap;
+struct dev_pagemap;
 
 #ifdef CONFIG_MEMORY_HOTPLUG
 /*
@@ -326,7 +327,7 @@ extern int add_memory_resource(int nid, struct resource *resource, bool online);
 extern int arch_add_memory(int nid, u64 start, u64 size,
 		struct vmem_altmap *altmap, bool want_memblock);
 extern void move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
-		unsigned long nr_pages, struct vmem_altmap *altmap);
+		unsigned long nr_pages, struct dev_pagemap *pgmap);
 extern int offline_pages(unsigned long start_pfn, unsigned long nr_pages);
 extern bool is_memblock_offlined(struct memory_block *mem);
 extern void remove_memory(int nid, u64 start, u64 size);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index a0fbb9ffe380..319d01372efa 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -2140,7 +2140,7 @@ static inline void zero_resv_unavail(void) {}
 
 extern void set_dma_reserve(unsigned long new_dma_reserve);
 extern void memmap_init_zone(unsigned long, int, unsigned long, unsigned long,
-		enum memmap_context, struct vmem_altmap *);
+		enum memmap_context, struct dev_pagemap *);
 extern void setup_per_zone_wmarks(void);
 extern int __meminit init_per_zone_wmark_min(void);
 extern void mem_init(void);
diff --git a/kernel/memremap.c b/kernel/memremap.c
index ecee37b44aa1..58327259420d 100644
--- a/kernel/memremap.c
+++ b/kernel/memremap.c
@@ -244,7 +244,7 @@ void *devm_memremap_pages(struct device *dev, struct dev_pagemap *pgmap,
 		zone = &NODE_DATA(nid)->node_zones[ZONE_DEVICE];
 		if (!error)
 			move_pfn_range_to_zone(zone, align_start >> PAGE_SHIFT,
-					align_size >> PAGE_SHIFT, altmap);
+					align_size >> PAGE_SHIFT, pgmap);
 	}
 
 	mem_hotplug_done();
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index 7deb49f69e27..aae4e6cc65e9 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -779,7 +779,7 @@ static void __meminit resize_pgdat_range(struct pglist_data *pgdat, unsigned lon
 }
 
 void __ref move_pfn_range_to_zone(struct zone *zone, unsigned long start_pfn,
-		unsigned long nr_pages, struct vmem_altmap *altmap)
+		unsigned long nr_pages, struct dev_pagemap *pgmap)
 {
 	struct pglist_data *pgdat = zone->zone_pgdat;
 	int nid = pgdat->node_id;
@@ -805,7 +805,7 @@ void __ref 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_zone(nr_pages, nid, zone_idx(zone), start_pfn,
-			MEMMAP_HOTPLUG, altmap);
+			MEMMAP_HOTPLUG, pgmap);
 
 	set_zone_contiguous(zone);
 }
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1521100f1e63..545a5860cce7 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -5459,10 +5459,11 @@ void __ref build_all_zonelists(pg_data_t *pgdat)
  */
 void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
 		unsigned long start_pfn, enum memmap_context context,
-		struct vmem_altmap *altmap)
+		struct dev_pagemap *pgmap)
 {
 	unsigned long end_pfn = start_pfn + size;
 	pg_data_t *pgdat = NODE_DATA(nid);
+	struct vmem_altmap *altmap = NULL;
 	unsigned long pfn;
 	unsigned long nr_initialised = 0;
 	struct page *page;
@@ -5477,6 +5478,8 @@ void __meminit memmap_init_zone(unsigned long size, int nid, unsigned long zone,
 	 * Honor reservation requested by the driver for this ZONE_DEVICE
 	 * memory
 	 */
+	if (pgmap && pgmap->altmap_valid)
+		altmap = &pgmap->altmap;
 	if (altmap && start_pfn == altmap->base_pfn)
 		start_pfn += altmap->reserve;