[ARM] rationalize memory configuration code some more

Currently there are two instances of struct meminfo: one in
kernel/setup.c marked __initdata, and another in mm/init.c with
permanent storage.  Let's keep only the later to directly populate
the permanent version from arm_add_memory().

Also move common validation tests between the MMU and non-MMU cases
into arm_add_memory() to remove some duplication.  Protection against
overflowing the membank array is also moved in there in order to cover
the kernel cmdline parsing path as well.
Signed-off-by: Nicolas Pitre <nico@marvell.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/include/asm/setup.h

@@ -209,9 +209,11 @@ struct meminfo {
 	struct membank bank[NR_BANKS];
 };
 
+extern struct meminfo meminfo;
+
 #define for_each_nodebank(iter,mi,no)			\
-	for (iter = 0; iter < mi->nr_banks; iter++)	\
-		if (mi->bank[iter].node == no)
+	for (iter = 0; iter < (mi)->nr_banks; iter++)	\
+		if ((mi)->bank[iter].node == no)
 
 #define bank_pfn_start(bank)	__phys_to_pfn((bank)->start)
 #define bank_pfn_end(bank)	__phys_to_pfn((bank)->start + (bank)->size)

arch/arm/kernel/setup.c

@@ -59,7 +59,7 @@ static int __init fpe_setup(char *line)
 __setup("fpe=", fpe_setup);
 #endif
 
-extern void paging_init(struct meminfo *, struct machine_desc *desc);
+extern void paging_init(struct machine_desc *desc);
 extern void reboot_setup(char *str);
 extern void _text, _etext, __data_start, _edata, _end;
 
@@ -112,7 +112,6 @@ static struct stack stacks[NR_CPUS];
 char elf_platform[ELF_PLATFORM_SIZE];
 EXPORT_SYMBOL(elf_platform);
 
-static struct meminfo meminfo __initdata = { 0, };
 static const char *cpu_name;
 static const char *machine_name;
 static char __initdata command_line[COMMAND_LINE_SIZE];
@@ -367,21 +366,34 @@ static struct machine_desc * __init setup_machine(unsigned int nr)
 	return list;
 }
 
-static void __init arm_add_memory(unsigned long start, unsigned long size)
+static int __init arm_add_memory(unsigned long start, unsigned long size)
 {
-	struct membank *bank;
+	struct membank *bank = &meminfo.bank[meminfo.nr_banks];
+
+	if (meminfo.nr_banks >= NR_BANKS) {
+		printk(KERN_CRIT "NR_BANKS too low, "
+			"ignoring memory at %#lx\n", start);
+		return -EINVAL;
+	}
 
 	/*
 	 * Ensure that start/size are aligned to a page boundary.
 	 * Size is appropriately rounded down, start is rounded up.
 	 */
 	size -= start & ~PAGE_MASK;
-
-	bank = &meminfo.bank[meminfo.nr_banks++];
-
 	bank->start = PAGE_ALIGN(start);
 	bank->size  = size & PAGE_MASK;
 	bank->node  = PHYS_TO_NID(start);
+
+	/*
+	 * Check whether this memory region has non-zero size or
+	 * invalid node number.
+	 */
+	if (bank->size == 0 || bank->node >= MAX_NUMNODES)
+		return -EINVAL;
+
+	meminfo.nr_banks++;
+	return 0;
 }
 
 /*
@@ -539,14 +551,7 @@ __tagtable(ATAG_CORE, parse_tag_core);
 
 static int __init parse_tag_mem32(const struct tag *tag)
 {
-	if (meminfo.nr_banks >= NR_BANKS) {
-		printk(KERN_WARNING
-		       "Ignoring memory bank 0x%08x size %dKB\n",
-			tag->u.mem.start, tag->u.mem.size / 1024);
-		return -EINVAL;
-	}
-	arm_add_memory(tag->u.mem.start, tag->u.mem.size);
-	return 0;
+	return arm_add_memory(tag->u.mem.start, tag->u.mem.size);
 }
 
 __tagtable(ATAG_MEM, parse_tag_mem32);
@@ -718,7 +723,7 @@ void __init setup_arch(char **cmdline_p)
 	memcpy(boot_command_line, from, COMMAND_LINE_SIZE);
 	boot_command_line[COMMAND_LINE_SIZE-1] = '\0';
 	parse_cmdline(cmdline_p, from);
-	paging_init(&meminfo, mdesc);
+	paging_init(mdesc);
 	request_standard_resources(&meminfo, mdesc);
 
 #ifdef CONFIG_SMP

arch/arm/mm/init.c

@@ -64,10 +64,11 @@ static int __init parse_tag_initrd2(const struct tag *tag)
 __tagtable(ATAG_INITRD2, parse_tag_initrd2);
 
 /*
- * This is used to pass memory configuration data from paging_init
- * to mem_init, and by show_mem() to skip holes in the memory map.
+ * This keeps memory configuration data used by a couple memory
+ * initialization functions, as well as show_mem() for the skipping
+ * of holes in the memory map.  It is populated by arm_add_memory().
  */
-static struct meminfo meminfo = { 0, };
+struct meminfo meminfo;
 
 void show_mem(void)
 {
@@ -331,13 +332,12 @@ static void __init bootmem_free_node(int node, struct meminfo *mi)
 	free_area_init_node(node, zone_size, start_pfn, zhole_size);
 }
 
-void __init bootmem_init(struct meminfo *mi)
+void __init bootmem_init(void)
 {
+	struct meminfo *mi = &meminfo;
 	unsigned long memend_pfn = 0;
 	int node, initrd_node;
 
-	memcpy(&meminfo, mi, sizeof(meminfo));
-
 	/*
 	 * Locate which node contains the ramdisk image, if any.
 	 */

arch/arm/mm/mm.h

@@ -32,7 +32,7 @@ struct meminfo;
 struct pglist_data;
 
 void __init create_mapping(struct map_desc *md);
-void __init bootmem_init(struct meminfo *mi);
+void __init bootmem_init(void);
 void reserve_node_zero(struct pglist_data *pgdat);
 
 extern void _text, _stext, _etext, __data_start, _end, __init_begin, __init_end;

arch/arm/mm/mmu.c

@@ -653,13 +653,6 @@ __early_param("vmalloc=", early_vmalloc);
 
 static int __init check_membank_valid(struct membank *mb)
 {
-	/*
-	 * Check whether this memory region has non-zero size or
-	 * invalid node number.
-	 */
-	if (mb->size == 0 || mb->node >= MAX_NUMNODES)
-		return 0;
-
 	/*
 	 * Check whether this memory region would entirely overlap
 	 * the vmalloc area.
@@ -689,18 +682,18 @@ static int __init check_membank_valid(struct membank *mb)
 	return 1;
 }
 
-static void __init sanity_check_meminfo(struct meminfo *mi)
+static void __init sanity_check_meminfo(void)
 {
 	int i, j;
 
-	for (i = 0, j = 0; i < mi->nr_banks; i++) {
-		if (check_membank_valid(&mi->bank[i]))
-			mi->bank[j++] = mi->bank[i];
+	for (i = 0, j = 0; i < meminfo.nr_banks; i++) {
+		if (check_membank_valid(&meminfo.bank[i]))
+			meminfo.bank[j++] = meminfo.bank[i];
 	}
-	mi->nr_banks = j;
+	meminfo.nr_banks = j;
 }
 
-static inline void prepare_page_table(struct meminfo *mi)
+static inline void prepare_page_table(void)
 {
 	unsigned long addr;
 
@@ -721,7 +714,7 @@ static inline void prepare_page_table(struct meminfo *mi)
 	 * Clear out all the kernel space mappings, except for the first
 	 * memory bank, up to the end of the vmalloc region.
 	 */
-	for (addr = __phys_to_virt(mi->bank[0].start + mi->bank[0].size);
+	for (addr = __phys_to_virt(bank_phys_end(&meminfo.bank[0]));
 	     addr < VMALLOC_END; addr += PGDIR_SIZE)
 		pmd_clear(pmd_off_k(addr));
 }
@@ -880,14 +873,14 @@ static void __init devicemaps_init(struct machine_desc *mdesc)
  * paging_init() sets up the page tables, initialises the zone memory
  * maps, and sets up the zero page, bad page and bad page tables.
  */
-void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)
+void __init paging_init(struct machine_desc *mdesc)
 {
 	void *zero_page;
 
 	build_mem_type_table();
-	sanity_check_meminfo(mi);
-	prepare_page_table(mi);
-	bootmem_init(mi);
+	sanity_check_meminfo();
+	prepare_page_table();
+	bootmem_init();
 	devicemaps_init(mdesc);
 
 	top_pmd = pmd_off_k(0xffff0000);

arch/arm/mm/nommu.c

@@ -41,27 +41,13 @@ void __init reserve_node_zero(pg_data_t *pgdat)
 			BOOTMEM_DEFAULT);
 }
 
-static void __init sanity_check_meminfo(struct meminfo *mi)
-{
-	int i, j;
-
-	for (i = 0, j = 0; i < mi->nr_banks; i++) {
-		struct membank *mb = &mi->bank[i];
-
-		if (mb->size != 0 && mb->node < MAX_NUMNODES)
-			mi->bank[j++] = mi->bank[i];
-	}
-	mi->nr_banks = j;
-}
-
 /*
  * paging_init() sets up the page tables, initialises the zone memory
  * maps, and sets up the zero page, bad page and bad page tables.
  */
-void __init paging_init(struct meminfo *mi, struct machine_desc *mdesc)
+void __init paging_init(struct machine_desc *mdesc)
 {
-	sanity_check_meminfo(mi);
-	bootmem_init(mi);
+	bootmem_init();
 }
 
 /*