mm: remove CONFIG_HAVE_MEMBLOCK_NODE_MAP option

CONFIG_HAVE_MEMBLOCK_NODE_MAP is used to differentiate initialization of
nodes and zones structures between the systems that have region to node
mapping in memblock and those that don't.

Currently all the NUMA architectures enable this option and for the
non-NUMA systems we can presume that all the memory belongs to node 0 and
therefore the compile time configuration option is not required.

The remaining few architectures that use DISCONTIGMEM without NUMA are
easily updated to use memblock_add_node() instead of memblock_add() and
thus have proper correspondence of memblock regions to NUMA nodes.

Still, free_area_init_node() must have a backward compatible version
because its semantics with and without CONFIG_HAVE_MEMBLOCK_NODE_MAP is
different.  Once all the architectures will use the new semantics, the
entire compatibility layer can be dropped.

To avoid addition of extra run time memory to store node id for
architectures that keep memblock but have only a single node, the node id
field of the memblock_region is guarded by CONFIG_NEED_MULTIPLE_NODES and
the corresponding accessors presume that in those cases it is always 0.

Signed-off-by: Mike Rapoport <rppt@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Tested-by: Hoan Tran <hoan@os.amperecomputing.com>	[arm64]
Acked-by: Catalin Marinas <catalin.marinas@arm.com>	[arm64]
Cc: Baoquan He <bhe@redhat.com>
Cc: Brian Cain <bcain@codeaurora.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Geert Uytterhoeven <geert@linux-m68k.org>
Cc: Greentime Hu <green.hu@gmail.com>
Cc: Greg Ungerer <gerg@linux-m68k.org>
Cc: Guan Xuetao <gxt@pku.edu.cn>
Cc: Guo Ren <guoren@kernel.org>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Helge Deller <deller@gmx.de>
Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: Ley Foon Tan <ley.foon.tan@intel.com>
Cc: Mark Salter <msalter@redhat.com>
Cc: Matt Turner <mattst88@gmail.com>
Cc: Max Filippov <jcmvbkbc@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Michal Hocko <mhocko@kernel.org>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Nick Hu <nickhu@andestech.com>
Cc: Paul Walmsley <paul.walmsley@sifive.com>
Cc: Richard Weinberger <richard@nod.at>
Cc: Rich Felker <dalias@libc.org>
Cc: Russell King <linux@armlinux.org.uk>
Cc: Stafford Horne <shorne@gmail.com>
Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de>
Cc: Tony Luck <tony.luck@intel.com>
Cc: Vineet Gupta <vgupta@synopsys.com>
Cc: Yoshinori Sato <ysato@users.sourceforge.jp>
Link: http://lkml.kernel.org/r/20200412194859.12663-4-rppt@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

4 files changed, 64 insertions, 55 deletions

diff --git a/mm/Kconfig b/mm/Kconfig
index 5c0362bd8d56..3af64646f343 100644
--- a/mm/Kconfig
+++ b/mm/Kconfig
@@ -126,9 +126,6 @@ config SPARSEMEM_VMEMMAP
 	  pfn_to_page and page_to_pfn operations.  This is the most
 	  efficient option when sufficient kernel resources are available.
 
-config HAVE_MEMBLOCK_NODE_MAP
-	bool
-
 config HAVE_MEMBLOCK_PHYS_MAP
 	bool
 
diff --git a/mm/memblock.c b/mm/memblock.c
index 43e2fd3006c1..743659d88fc4 100644
--- a/mm/memblock.c
+++ b/mm/memblock.c
@@ -620,7 +620,7 @@ repeat:
 		 * area, insert that portion.
 		 */
 		if (rbase > base) {
-#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+#ifdef CONFIG_NEED_MULTIPLE_NODES
 			WARN_ON(nid != memblock_get_region_node(rgn));
 #endif
 			WARN_ON(flags != rgn->flags);
@@ -1197,7 +1197,6 @@ void __init_memblock __next_mem_range_rev(u64 *idx, int nid,
 	*idx = ULLONG_MAX;
 }
 
-#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 /*
  * Common iterator interface used to define for_each_mem_pfn_range().
  */
@@ -1247,6 +1246,7 @@ void __init_memblock __next_mem_pfn_range(int *idx, int nid,
 int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
 				      struct memblock_type *type, int nid)
 {
+#ifdef CONFIG_NEED_MULTIPLE_NODES
 	int start_rgn, end_rgn;
 	int i, ret;
 
@@ -1258,9 +1258,10 @@ int __init_memblock memblock_set_node(phys_addr_t base, phys_addr_t size,
 		memblock_set_region_node(&type->regions[i], nid);
 
 	memblock_merge_regions(type);
+#endif
 	return 0;
 }
-#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
+
 #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
 /**
  * __next_mem_pfn_range_in_zone - iterator for for_each_*_range_in_zone()
@@ -1799,7 +1800,6 @@ bool __init_memblock memblock_is_map_memory(phys_addr_t addr)
 	return !memblock_is_nomap(&memblock.memory.regions[i]);
 }
 
-#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 int __init_memblock memblock_search_pfn_nid(unsigned long pfn,
 			 unsigned long *start_pfn, unsigned long *end_pfn)
 {
@@ -1814,7 +1814,6 @@ int __init_memblock memblock_search_pfn_nid(unsigned long pfn,
 
 	return memblock_get_region_node(&type->regions[mid]);
 }
-#endif
 
 /**
  * memblock_is_region_memory - check if a region is a subset of memory
@@ -1905,7 +1904,7 @@ static void __init_memblock memblock_dump(struct memblock_type *type)
 		size = rgn->size;
 		end = base + size - 1;
 		flags = rgn->flags;
-#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
+#ifdef CONFIG_NEED_MULTIPLE_NODES
 		if (memblock_get_region_node(rgn) != MAX_NUMNODES)
 			snprintf(nid_buf, sizeof(nid_buf), " on node %d",
 				 memblock_get_region_node(rgn));
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c
index fc0aad0bc1f5..e67dc501576a 100644
--- a/mm/memory_hotplug.c
+++ b/mm/memory_hotplug.c
@@ -1372,11 +1372,7 @@ check_pages_isolated_cb(unsigned long start_pfn, unsigned long nr_pages,
 
 static int __init cmdline_parse_movable_node(char *p)
 {
-#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 	movable_node_enabled = true;
-#else
-	pr_warn("movable_node parameter depends on CONFIG_HAVE_MEMBLOCK_NODE_MAP to work properly\n");
-#endif
 	return 0;
 }
 early_param("movable_node", cmdline_parse_movable_node);
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 8741ae0828e1..430e35384b78 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -335,7 +335,6 @@ static unsigned long nr_kernel_pages __initdata;
 static unsigned long nr_all_pages __initdata;
 static unsigned long dma_reserve __initdata;
 
-#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 static unsigned long arch_zone_lowest_possible_pfn[MAX_NR_ZONES] __initdata;
 static unsigned long arch_zone_highest_possible_pfn[MAX_NR_ZONES] __initdata;
 static unsigned long required_kernelcore __initdata;
@@ -348,7 +347,6 @@ static bool mirrored_kernelcore __meminitdata;
 /* movable_zone is the "real" zone pages in ZONE_MOVABLE are taken from */
 int movable_zone;
 EXPORT_SYMBOL(movable_zone);
-#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
 
 #if MAX_NUMNODES > 1
 unsigned int nr_node_ids __read_mostly = MAX_NUMNODES;
@@ -1499,8 +1497,7 @@ void __free_pages_core(struct page *page, unsigned int order)
 	__free_pages(page, order);
 }
 
-#if defined(CONFIG_HAVE_ARCH_EARLY_PFN_TO_NID) || \
-	defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP)
+#ifdef CONFIG_NEED_MULTIPLE_NODES
 
 static struct mminit_pfnnid_cache early_pfnnid_cache __meminitdata;
 
@@ -1542,7 +1539,7 @@ int __meminit early_pfn_to_nid(unsigned long pfn)
 
 	return nid;
 }
-#endif
+#endif /* CONFIG_NEED_MULTIPLE_NODES */
 
 #ifdef CONFIG_NODES_SPAN_OTHER_NODES
 /* Only safe to use early in boot when initialisation is single-threaded */
@@ -5936,7 +5933,6 @@ void __ref build_all_zonelists(pg_data_t *pgdat)
 static bool __meminit
 overlap_memmap_init(unsigned long zone, unsigned long *pfn)
 {
-#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
 	static struct memblock_region *r;
 
 	if (mirrored_kernelcore && zone == ZONE_MOVABLE) {
@@ -5952,7 +5948,6 @@ overlap_memmap_init(unsigned long zone, unsigned long *pfn)
 			return true;
 		}
 	}
-#endif
 	return false;
 }
 
@@ -6585,8 +6580,7 @@ static unsigned long __init zone_absent_pages_in_node(int nid,
 	return nr_absent;
 }
 
-#else /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
-static inline unsigned long __init zone_spanned_pages_in_node(int nid,
+static inline unsigned long __init compat_zone_spanned_pages_in_node(int nid,
 					unsigned long zone_type,
 					unsigned long node_start_pfn,
 					unsigned long node_end_pfn,
@@ -6605,7 +6599,7 @@ static inline unsigned long __init zone_spanned_pages_in_node(int nid,
 	return zones_size[zone_type];
 }
 
-static inline unsigned long __init zone_absent_pages_in_node(int nid,
+static inline unsigned long __init compat_zone_absent_pages_in_node(int nid,
 						unsigned long zone_type,
 						unsigned long node_start_pfn,
 						unsigned long node_end_pfn,
@@ -6617,13 +6611,12 @@ static inline unsigned long __init zone_absent_pages_in_node(int nid,
 	return zholes_size[zone_type];
 }
 
-#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
-
 static void __init calculate_node_totalpages(struct pglist_data *pgdat,
 						unsigned long node_start_pfn,
 						unsigned long node_end_pfn,
 						unsigned long *zones_size,
-						unsigned long *zholes_size)
+						unsigned long *zholes_size,
+						bool compat)
 {
 	unsigned long realtotalpages = 0, totalpages = 0;
 	enum zone_type i;
@@ -6631,17 +6624,38 @@ static void __init calculate_node_totalpages(struct pglist_data *pgdat,
 	for (i = 0; i < MAX_NR_ZONES; i++) {
 		struct zone *zone = pgdat->node_zones + i;
 		unsigned long zone_start_pfn, zone_end_pfn;
+		unsigned long spanned, absent;
 		unsigned long size, real_size;
 
-		size = zone_spanned_pages_in_node(pgdat->node_id, i,
-						  node_start_pfn,
-						  node_end_pfn,
-						  &zone_start_pfn,
-						  &zone_end_pfn,
-						  zones_size);
-		real_size = size - zone_absent_pages_in_node(pgdat->node_id, i,
-						  node_start_pfn, node_end_pfn,
-						  zholes_size);
+		if (compat) {
+			spanned = compat_zone_spanned_pages_in_node(
+						pgdat->node_id, i,
+						node_start_pfn,
+						node_end_pfn,
+						&zone_start_pfn,
+						&zone_end_pfn,
+						zones_size);
+			absent = compat_zone_absent_pages_in_node(
+						pgdat->node_id, i,
+						node_start_pfn,
+						node_end_pfn,
+						zholes_size);
+		} else {
+			spanned = zone_spanned_pages_in_node(pgdat->node_id, i,
+						node_start_pfn,
+						node_end_pfn,
+						&zone_start_pfn,
+						&zone_end_pfn,
+						zones_size);
+			absent = zone_absent_pages_in_node(pgdat->node_id, i,
+						node_start_pfn,
+						node_end_pfn,
+						zholes_size);
+		}
+
+		size = spanned;
+		real_size = size - absent;
+
 		if (size)
 			zone->zone_start_pfn = zone_start_pfn;
 		else
@@ -6941,10 +6955,8 @@ static void __ref alloc_node_mem_map(struct pglist_data *pgdat)
 	 */
 	if (pgdat == NODE_DATA(0)) {
 		mem_map = NODE_DATA(0)->node_mem_map;
-#if defined(CONFIG_HAVE_MEMBLOCK_NODE_MAP) || defined(CONFIG_FLATMEM)
 		if (page_to_pfn(mem_map) != pgdat->node_start_pfn)
 			mem_map -= offset;
-#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
 	}
 #endif
 }
@@ -6961,9 +6973,10 @@ static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
 static inline void pgdat_set_deferred_range(pg_data_t *pgdat) {}
 #endif
 
-void __init free_area_init_node(int nid, unsigned long *zones_size,
-				   unsigned long node_start_pfn,
-				   unsigned long *zholes_size)
+static void __init __free_area_init_node(int nid, unsigned long *zones_size,
+					 unsigned long node_start_pfn,
+					 unsigned long *zholes_size,
+					 bool compat)
 {
 	pg_data_t *pgdat = NODE_DATA(nid);
 	unsigned long start_pfn = 0;
@@ -6975,16 +6988,16 @@ void __init free_area_init_node(int nid, unsigned long *zones_size,
 	pgdat->node_id = nid;
 	pgdat->node_start_pfn = node_start_pfn;
 	pgdat->per_cpu_nodestats = NULL;
-#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
-	get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
-	pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
-		(u64)start_pfn << PAGE_SHIFT,
-		end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
-#else
-	start_pfn = node_start_pfn;
-#endif
+	if (!compat) {
+		get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
+		pr_info("Initmem setup node %d [mem %#018Lx-%#018Lx]\n", nid,
+			(u64)start_pfn << PAGE_SHIFT,
+			end_pfn ? ((u64)end_pfn << PAGE_SHIFT) - 1 : 0);
+	} else {
+		start_pfn = node_start_pfn;
+	}
 	calculate_node_totalpages(pgdat, start_pfn, end_pfn,
-				  zones_size, zholes_size);
+				  zones_size, zholes_size, compat);
 
 	alloc_node_mem_map(pgdat);
 	pgdat_set_deferred_range(pgdat);
@@ -6992,6 +7005,14 @@ void __init free_area_init_node(int nid, unsigned long *zones_size,
 	free_area_init_core(pgdat);
 }
 
+void __init free_area_init_node(int nid, unsigned long *zones_size,
+				unsigned long node_start_pfn,
+				unsigned long *zholes_size)
+{
+	__free_area_init_node(nid, zones_size, node_start_pfn, zholes_size,
+			      true);
+}
+
 #if !defined(CONFIG_FLAT_NODE_MEM_MAP)
 /*
  * Initialize all valid struct pages in the range [spfn, epfn) and mark them
@@ -7075,8 +7096,6 @@ static inline void __init init_unavailable_mem(void)
 }
 #endif /* !CONFIG_FLAT_NODE_MEM_MAP */
 
-#ifdef CONFIG_HAVE_MEMBLOCK_NODE_MAP
-
 #if MAX_NUMNODES > 1
 /*
  * Figure out the number of possible node ids.
@@ -7505,8 +7524,8 @@ void __init free_area_init_nodes(unsigned long *max_zone_pfn)
 	init_unavailable_mem();
 	for_each_online_node(nid) {
 		pg_data_t *pgdat = NODE_DATA(nid);
-		free_area_init_node(nid, NULL,
-				find_min_pfn_for_node(nid), NULL);
+		__free_area_init_node(nid, NULL,
+				      find_min_pfn_for_node(nid), NULL, false);
 
 		/* Any memory on that node */
 		if (pgdat->node_present_pages)
@@ -7571,8 +7590,6 @@ static int __init cmdline_parse_movablecore(char *p)
 early_param("kernelcore", cmdline_parse_kernelcore);
 early_param("movablecore", cmdline_parse_movablecore);
 
-#endif /* CONFIG_HAVE_MEMBLOCK_NODE_MAP */
-
 void adjust_managed_page_count(struct page *page, long count)
 {
 	atomic_long_add(count, &page_zone(page)->managed_pages);