1 files changed, 93 insertions, 1 deletions

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 8e3c9c5a3042..b219ccc015d6 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -291,6 +291,57 @@ static unsigned long cached_align;
 
 static unsigned long vmap_area_pcpu_hole;
 
+#ifdef CONFIG_ENABLE_VMALLOC_SAVING
+#define POSSIBLE_VMALLOC_START	PAGE_OFFSET
+
+#define VMALLOC_BITMAP_SIZE	((VMALLOC_END - PAGE_OFFSET) >> \
+					PAGE_SHIFT)
+#define VMALLOC_TO_BIT(addr)	((addr - PAGE_OFFSET) >> PAGE_SHIFT)
+#define BIT_TO_VMALLOC(i)	(PAGE_OFFSET + i * PAGE_SIZE)
+
+unsigned long total_vmalloc_size;
+unsigned long vmalloc_reserved;
+
+DECLARE_BITMAP(possible_areas, VMALLOC_BITMAP_SIZE);
+
+void mark_vmalloc_reserved_area(void *x, unsigned long size)
+{
+	unsigned long addr = (unsigned long)x;
+
+	bitmap_set(possible_areas, VMALLOC_TO_BIT(addr), size >> PAGE_SHIFT);
+	vmalloc_reserved += size;
+}
+
+int is_vmalloc_addr(const void *x)
+{
+	unsigned long addr = (unsigned long)x;
+
+	if (addr < POSSIBLE_VMALLOC_START || addr >= VMALLOC_END)
+		return 0;
+
+	if (test_bit(VMALLOC_TO_BIT(addr), possible_areas))
+		return 0;
+
+	return 1;
+}
+
+static void calc_total_vmalloc_size(void)
+{
+	total_vmalloc_size = VMALLOC_END - POSSIBLE_VMALLOC_START -
+		vmalloc_reserved;
+}
+#else
+int is_vmalloc_addr(const void *x)
+{
+	unsigned long addr = (unsigned long)x;
+
+	return addr >= VMALLOC_START && addr < VMALLOC_END;
+}
+
+static void calc_total_vmalloc_size(void) { }
+#endif
+EXPORT_SYMBOL(is_vmalloc_addr);
+
 static struct vmap_area *__find_vmap_area(unsigned long addr)
 {
 	struct rb_node *n = vmap_area_root.rb_node;
@@ -1144,6 +1195,33 @@ void *vm_map_ram(struct page **pages, unsigned int count, int node, pgprot_t pro
 EXPORT_SYMBOL(vm_map_ram);
 
 static struct vm_struct *vmlist __initdata;
+
+/**
+ * vm_area_check_early - check if vmap area is already mapped
+ * @vm: vm_struct to be checked
+ *
+ * This function is used to check if the vmap area has been
+ * mapped already. @vm->addr, @vm->size and @vm->flags should
+ * contain proper values.
+ *
+ */
+int __init vm_area_check_early(struct vm_struct *vm)
+{
+	struct vm_struct *tmp, **p;
+
+	BUG_ON(vmap_initialized);
+	for (p = &vmlist; (tmp = *p) != NULL; p = &tmp->next) {
+		if (tmp->addr >= vm->addr) {
+			if (tmp->addr < vm->addr + vm->size)
+				return 1;
+		} else {
+			if (tmp->addr + tmp->size > vm->addr)
+				return 1;
+		}
+	}
+	return 0;
+}
+
 /**
  * vm_area_add_early - add vmap area early during boot
  * @vm: vm_struct to add
@@ -1224,7 +1302,7 @@ void __init vmalloc_init(void)
 	}
 
 	vmap_area_pcpu_hole = VMALLOC_END;
-
+	calc_total_vmalloc_size();
 	vmap_initialized = true;
 }
 
@@ -1388,16 +1466,27 @@ struct vm_struct *__get_vm_area_caller(unsigned long size, unsigned long flags,
  */
 struct vm_struct *get_vm_area(unsigned long size, unsigned long flags)
 {
+#ifdef CONFIG_ENABLE_VMALLOC_SAVING
+	return __get_vm_area_node(size, 1, flags, PAGE_OFFSET, VMALLOC_END,
+				  NUMA_NO_NODE, GFP_KERNEL,
+				  __builtin_return_address(0));
+#else
 	return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
 				  NUMA_NO_NODE, GFP_KERNEL,
 				  __builtin_return_address(0));
+#endif
 }
 
 struct vm_struct *get_vm_area_caller(unsigned long size, unsigned long flags,
 				const void *caller)
 {
+#ifdef CONFIG_ENABLE_VMALLOC_SAVING
+	return __get_vm_area_node(size, 1, flags, PAGE_OFFSET, VMALLOC_END,
+				  NUMA_NO_NODE, GFP_KERNEL, caller);
+#else
 	return __get_vm_area_node(size, 1, flags, VMALLOC_START, VMALLOC_END,
 				  NUMA_NO_NODE, GFP_KERNEL, caller);
+#endif
 }
 
 /**
@@ -2654,6 +2743,9 @@ static int s_show(struct seq_file *m, void *p)
 	if (v->flags & VM_VPAGES)
 		seq_puts(m, " vpages");
 
+	if (v->flags & VM_LOWMEM)
+		seq_puts(m, " lowmem");
+
 	show_numa_info(m, v);
 	seq_putc(m, '\n');
 	return 0;