[ARM] Parse initrd information early

We need the initrd location before the normal command line parsing
occurs so we can reserve the right bits of memory, and not double-
free the initrd during userspace boot.

arch/arm/kernel/setup.c

@@ -81,6 +81,8 @@ struct cpu_user_fns cpu_user;
 unsigned char aux_device_present;
 char elf_platform[ELF_PLATFORM_SIZE];
 char saved_command_line[COMMAND_LINE_SIZE];
+unsigned long phys_initrd_start __initdata = 0;
+unsigned long phys_initrd_size __initdata = 0;
 
 static struct meminfo meminfo __initdata = { 0, };
 static struct proc_info_item proc_info;
@@ -330,6 +332,22 @@ parse_cmdline(struct meminfo *mi, char **cmdline_p, char *from)
 			mi->bank[mi->nr_banks].size  = size;
 			mi->bank[mi->nr_banks].node  = PHYS_TO_NID(start);
 			mi->nr_banks += 1;
+		} else if (c == ' ' && !memcmp(from, "initrd=", 7)) {
+			unsigned long start, size;
+
+			/*
+			 * Remove space character
+			 */
+			if (to != command_line)
+				to -= 1;
+
+			start = memparse(from + 7, &from);
+			if (*from == ',') {
+				size = memparse(from + 1, &from);
+
+				phys_initrd_start = start;
+				phys_initrd_size = size;
+			}
 		}
 		c = *from++;
 		if (!c)
@@ -357,19 +375,6 @@ setup_ramdisk(int doload, int prompt, int image_start, unsigned int rd_sz)
 #endif
 }
 
-/*
- * initial ram disk
- */
-static void __init setup_initrd(unsigned int start, unsigned int size)
-{
-#ifdef CONFIG_BLK_DEV_INITRD
-	if (start == 0)
-		size = 0;
-	initrd_start = start;
-	initrd_end   = start + size;
-#endif
-}
-
 static void __init
 request_standard_resources(struct meminfo *mi, struct machine_desc *mdesc)
 {
@@ -503,7 +508,8 @@ __tagtable(ATAG_RAMDISK, parse_tag_ramdisk);
 
 static int __init parse_tag_initrd(const struct tag *tag)
 {
-	setup_initrd(tag->u.initrd.start, tag->u.initrd.size);
+	phys_initrd_start = __virt_to_phys(tag->u.initrd.start);
+	phys_initrd_size = tag->u.initrd.size;
 	return 0;
 }
 
@@ -511,13 +517,8 @@ __tagtable(ATAG_INITRD, parse_tag_initrd);
 
 static int __init parse_tag_initrd2(const struct tag *tag)
 {
-	unsigned long start = 0;
-
-	if (tag->u.initrd.size) {
-		start = (unsigned long)phys_to_virt(tag->u.initrd.start);
-
-		setup_initrd(start, tag->u.initrd.size);
-	}
+	phys_initrd_start = tag->u.initrd.start;
+	phys_initrd_size = tag->u.initrd.size;
 	return 0;
 }
 

arch/arm/mm/init.c

@@ -52,6 +52,8 @@ mmu_gather_t mmu_gathers[NR_CPUS];
 
 extern pgd_t swapper_pg_dir[PTRS_PER_PGD];
 extern char _stext, _text, _etext, _end, __init_begin, __init_end;
+extern unsigned long phys_initrd_start;
+extern unsigned long phys_initrd_size;
 
 /*
  * The sole use of this is to pass memory configuration
@@ -254,18 +256,17 @@ find_memend_and_nodes(struct meminfo *mi, struct node_info *np)
 static int __init check_initrd(struct meminfo *mi)
 {
 	int initrd_node = -2;
-
 #ifdef CONFIG_BLK_DEV_INITRD
+	unsigned long end = phys_initrd_start + phys_initrd_size;
+
 	/*
 	 * Make sure that the initrd is within a valid area of
 	 * memory.
 	 */
-	if (initrd_start) {
-		unsigned long phys_initrd_start, phys_initrd_end;
+	if (phys_initrd_size) {
 		unsigned int i;
 
-		phys_initrd_start = __pa(initrd_start);
-		phys_initrd_end   = __pa(initrd_end);
+		initrd_node = -1;
 
 		for (i = 0; i < mi->nr_banks; i++) {
 			unsigned long bank_end;
@@ -273,7 +274,7 @@ static int __init check_initrd(struct meminfo *mi)
 			bank_end = mi->bank[i].start + mi->bank[i].size;
 
 			if (mi->bank[i].start <= phys_initrd_start &&
-			    phys_initrd_end <= bank_end)
+			    end <= bank_end)
 				initrd_node = mi->bank[i].node;
 		}
 	}
@@ -281,8 +282,8 @@ static int __init check_initrd(struct meminfo *mi)
 	if (initrd_node == -1) {
 		printk(KERN_ERR "initrd (0x%08lx - 0x%08lx) extends beyond "
 		       "physical memory - disabling initrd\n",
-		       initrd_start, initrd_end);
-		initrd_start = initrd_end = 0;
+		       phys_initrd_start, end);
+		phys_initrd_start = phys_initrd_size = 0;
 	}
 #endif
 
@@ -423,9 +424,12 @@ void __init bootmem_init(struct meminfo *mi)
 
 
 #ifdef CONFIG_BLK_DEV_INITRD
-	if (initrd_node >= 0)
-		reserve_bootmem_node(NODE_DATA(initrd_node), __pa(initrd_start),
-				     initrd_end - initrd_start);
+	if (phys_initrd_size && initrd_node >= 0) {
+		reserve_bootmem_node(NODE_DATA(initrd_node), phys_initrd_start,
+				     phys_initrd_size);
+		initrd_start = __phys_to_virt(phys_initrd_start);
+		initrd_end = initrd_start + phys_initrd_size;
+	}
 #endif
 
 	if (map_pg != bootmap_pfn + bootmap_pages)