mm: Update is_vmalloc_addr to account for vmalloc savings

is_vmalloc_addr current assumes that all vmalloc addresses
exist between VMALLOC_START and VMALLOC_END. This may not be
the case when interleaving vmalloc and lowmem. Update the
is_vmalloc_addr to properly check for this.

Change-Id: I5def3d6ae1a4de59ea36f095b8c73649a37b1f36
Signed-off-by: Laura Abbott <lauraa@codeaurora.org>

4 files changed, 41 insertions, 7 deletions

diff --git a/arch/arm/mm/mmu.c b/arch/arm/mm/mmu.c
index 259cec5d4..2a26fea1e 100644
--- a/arch/arm/mm/mmu.c
+++ b/arch/arm/mm/mmu.c
@@ -868,7 +868,7 @@ void __init iotable_init(struct map_desc *io_desc, int nr)
 		vm->addr = (void *)(md->virtual & PAGE_MASK);
 		vm->size = PAGE_ALIGN(md->length + (md->virtual & ~PAGE_MASK));
 		vm->phys_addr = __pfn_to_phys(md->pfn);
-		vm->flags = VM_IOREMAP | VM_ARM_STATIC_MAPPING;
+		vm->flags = VM_LOWMEM | VM_ARM_STATIC_MAPPING;
 		vm->flags |= VM_ARM_MTYPE(md->type);
 		vm->caller = iotable_init;
 		add_static_vm_early(svm++);
diff --git a/include/linux/mm.h b/include/linux/mm.h
index 8aecdef77..7060750a8 100644
--- a/include/linux/mm.h
+++ b/include/linux/mm.h
@@ -325,16 +325,16 @@ unsigned long vmalloc_to_pfn(const void *addr);
  * On nommu, vmalloc/vfree wrap through kmalloc/kfree directly, so there
  * is no special casing required.
  */
-static inline int is_vmalloc_addr(const void *x)
-{
-#ifdef CONFIG_MMU
-	unsigned long addr = (unsigned long)x;
 
-	return addr >= VMALLOC_START && addr < VMALLOC_END;
+#ifdef CONFIG_MMU
+extern int is_vmalloc_addr(const void *x);
 #else
+static inline int is_vmalloc_addr(const void *x)
+{
 	return 0;
-#endif
 }
+#endif
+
 #ifdef CONFIG_MMU
 extern int is_vmalloc_or_module_addr(const void *x);
 #else
diff --git a/include/linux/vmalloc.h b/include/linux/vmalloc.h
index 8549594c7..c87676e71 100644
--- a/include/linux/vmalloc.h
+++ b/include/linux/vmalloc.h
@@ -16,6 +16,7 @@ struct vm_area_struct;		/* vma defining user mapping in mm_types.h */
 #define VM_USERMAP	0x00000008	/* suitable for remap_vmalloc_range */
 #define VM_VPAGES	0x00000010	/* buffer for pages was vmalloc'ed */
 #define VM_UNLIST	0x00000020	/* vm_struct is not listed in vmlist */
+#define VM_LOWMEM	0x00000040	/* Tracking of direct mapped lowmem */
 /* bits [20..32] reserved for arch specific ioremap internals */
 
 /*
diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 750340dbb..02cb4ce1b 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -204,6 +204,36 @@ static int vmap_page_range(unsigned long start, unsigned long end,
 	return ret;
 }
 
+#ifdef ENABLE_VMALLOC_SAVING
+int is_vmalloc_addr(const void *x)
+{
+	struct rb_node *n;
+	struct vmap_area *va;
+	int ret = 0;
+
+	spin_lock(&vmap_area_lock);
+
+	for (n = rb_first(vmap_area_root); n; rb_next(n)) {
+		va = rb_entry(n, struct vmap_area, rb_node);
+		if (x >= va->va_start && x < va->va_end) {
+			ret = 1;
+			break;
+		}
+	}
+
+	spin_unlock(&vmap_area_lock);
+	return ret;
+}
+#else
+int is_vmalloc_addr(const void *x)
+{
+	unsigned long addr = (unsigned long)x;
+
+	return addr >= VMALLOC_START && addr < VMALLOC_END;
+}
+#endif
+EXPORT_SYMBOL(is_vmalloc_addr);
+
 int is_vmalloc_or_module_addr(const void *x)
 {
 	/*
@@ -2636,6 +2666,9 @@ static int s_show(struct seq_file *m, void *p)
 	if (v->flags & VM_VPAGES)
 		seq_printf(m, " vpages");
 
+	if (v->flags & VM_LOWMEM)
+		seq_printf(m, " lowmem");
+
 	show_numa_info(m, v);
 	seq_putc(m, '\n');
 	return 0;