sh: sparsemem support.

This implements basic sparsemem support for SH. Presently this only
uses static sparsemem, and we still permit explicit selection of
flatmem. Those boards that want sparsemem can select it as usual.
Signed-off-by: NPaul Mundt <lethal@linux-sh.org>

arch/sh/kernel/setup.c

@@ -128,6 +128,7 @@ void __init setup_bootmem_allocator(unsigned long start_pfn)
 	bootmap_size = init_bootmem_node(NODE_DATA(0), start_pfn,
 					 min_low_pfn, max_low_pfn);
 
+	add_active_range(0, min_low_pfn, max_low_pfn);
 	register_bootmem_low_pages();
 
 	node_set_online(0);
@@ -192,6 +193,7 @@ static void __init setup_memory(void)
 	 */
 	start_pfn = PFN_UP(__pa(_end));
 	setup_bootmem_allocator(start_pfn);
+	sparse_memory_present_with_active_regions(0);
 }
 #else
 extern void __init setup_memory(void);
@@ -250,8 +252,9 @@ void __init setup_arch(char **cmdline_p)
 	min_low_pfn = __MEMORY_START >> PAGE_SHIFT;
 
 	nodes_clear(node_online_map);
+
+	/* Setup bootmem with available RAM */
 	setup_memory();
-	paging_init();
 	sparse_init();
 
 #ifdef CONFIG_DUMMY_CONSOLE
@@ -261,8 +264,9 @@ void __init setup_arch(char **cmdline_p)
 	/* Perform the machine specific initialisation */
 	if (likely(sh_mv.mv_setup))
 		sh_mv.mv_setup(cmdline_p);
-}
 
+	paging_init();
+}
 
 static const char *cpu_name[] = {
 	[CPU_SH7206]	= "SH7206",	[CPU_SH7619]	= "SH7619",

arch/sh/mm/Kconfig

@@ -300,6 +300,13 @@ config NODES_SHIFT
 config ARCH_FLATMEM_ENABLE
 	def_bool y
 
+config ARCH_SPARSEMEM_ENABLE
+	def_bool y
+	select SPARSEMEM_STATIC
+
+config ARCH_SPARSEMEM_DEFAULT
+	def_bool y
+
 config MAX_ACTIVE_REGIONS
 	int
 	default "1"
@@ -307,6 +314,9 @@ config MAX_ACTIVE_REGIONS
 config ARCH_POPULATES_NODE_MAP
 	def_bool y
 
+config ARCH_SELECT_MEMORY_MODEL
+	def_bool y
+
 choice
 	prompt "Kernel page size"
 	default PAGE_SIZE_4KB

arch/sh/mm/init.c

@@ -36,14 +36,11 @@ void show_mem(void)
 	show_free_areas();
 
 	for_each_online_pgdat(pgdat) {
-		struct page *page, *end;
-		unsigned long flags;
+		unsigned long flags, i;
 
 		pgdat_resize_lock(pgdat, &flags);
-		page = pgdat->node_mem_map;
-		end = page + pgdat->node_spanned_pages;
-
-		do {
+		for (i = 0; i < pgdat->node_spanned_pages; i++) {
+			struct page *page = pgdat_page_nr(pgdat, i);
 			total++;
 			if (PageReserved(page))
 				reserved++;
@@ -55,9 +52,7 @@ void show_mem(void)
 				free++;
 			else
 				shared += page_count(page) - 1;
-			page++;
-		} while (page < end);
-
+		}
 		pgdat_resize_unlock(pgdat, &flags);
 	}
 
@@ -169,15 +164,11 @@ void __init paging_init(void)
 		low = pgdat->bdata->node_low_pfn;
 
 		max_zone_pfns[ZONE_NORMAL] = low;
-		add_active_range(nid, start_pfn, low);
 
 		printk("Node %u: start_pfn = 0x%lx, low = 0x%lx\n",
 		       nid, start_pfn, low);
 
 		free_area_init_nodes(max_zone_pfns);
-
-		printk("Node %u: mem_map starts at %p\n",
-		       pgdat->node_id, pgdat->node_mem_map);
 	}
 }
 
@@ -185,16 +176,13 @@ static struct kcore_list kcore_mem, kcore_vmalloc;
 
 void __init mem_init(void)
 {
-	int codesize, reservedpages, datasize, initsize;
+	int codesize, datasize, initsize;
 	int nid;
 
-	reservedpages = 0;
-
 	for_each_online_node(nid) {
 		pg_data_t *pgdat = NODE_DATA(nid);
 		unsigned long node_pages = 0;
 		void *node_high_memory;
-		int i;
 
 		num_physpages += pgdat->node_present_pages;
 
@@ -203,10 +191,6 @@ void __init mem_init(void)
 
 		totalram_pages += node_pages;
 
-		for (i = 0; i < node_pages; i++)
-			if (PageReserved(pgdat->node_mem_map + i))
-				reservedpages++;
-
 		node_high_memory = (void *)((pgdat->node_start_pfn +
 					     pgdat->node_spanned_pages) <<
 						PAGE_SHIFT);
@@ -239,11 +223,10 @@ void __init mem_init(void)
 		   VMALLOC_END - VMALLOC_START);
 
 	printk(KERN_INFO "Memory: %luk/%luk available (%dk kernel code, "
-	       "%dk reserved, %dk data, %dk init)\n",
+	       "%dk data, %dk init)\n",
 		(unsigned long) nr_free_pages() << (PAGE_SHIFT-10),
 		totalram_pages << (PAGE_SHIFT-10),
 		codesize >> 10,
-		reservedpages << (PAGE_SHIFT-10),
 		datasize >> 10,
 		initsize >> 10);
 

include/asm-sh/sparsemem.h

+#ifndef __ASM_SH_SPARSEMEM_H
+#define __ASM_SH_SPARSEMEM_H
+
+#ifdef __KERNEL__
+/*
+ * SECTION_SIZE_BITS		2^N: how big each section will be
+ * MAX_PHYSADDR_BITS		2^N: how much physical address space we have
+ * MAX_PHYSMEM_BITS		2^N: how much memory we can have in that space
+ */
+#define SECTION_SIZE_BITS	26
+#define MAX_PHYSADDR_BITS	32
+#define MAX_PHYSMEM_BITS	32
+
+#endif
+
+#endif /* __ASM_SH_SPARSEMEM_H */