1 files changed, 57 insertions, 2 deletions

diff --git a/mm/vmalloc.c b/mm/vmalloc.c
index 8e05a11155c..3cee76a8c9f 100644
--- a/mm/vmalloc.c
+++ b/mm/vmalloc.c
@@ -164,6 +164,7 @@ int map_vm_area(struct vm_struct *area, pgprot_t prot, struct page ***pages)
 	flush_cache_vmap((unsigned long) area->addr, end);
 	return err;
 }
+EXPORT_SYMBOL_GPL(map_vm_area);
 
 static struct vm_struct *__get_vm_area_node(unsigned long size, unsigned long flags,
 					    unsigned long start, unsigned long end,
@@ -242,6 +243,7 @@ struct vm_struct *__get_vm_area(unsigned long size, unsigned long flags,
 {
 	return __get_vm_area_node(size, flags, start, end, -1, GFP_KERNEL);
 }
+EXPORT_SYMBOL_GPL(__get_vm_area);
 
 /**
  *	get_vm_area  -  reserve a contingous kernel virtual area
@@ -583,9 +585,9 @@ void *vmalloc_exec(unsigned long size)
 }
 
 #if defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA32)
-#define GFP_VMALLOC32 GFP_DMA32
+#define GFP_VMALLOC32 GFP_DMA32 | GFP_KERNEL
 #elif defined(CONFIG_64BIT) && defined(CONFIG_ZONE_DMA)
-#define GFP_VMALLOC32 GFP_DMA
+#define GFP_VMALLOC32 GFP_DMA | GFP_KERNEL
 #else
 #define GFP_VMALLOC32 GFP_KERNEL
 #endif
@@ -767,3 +769,56 @@ EXPORT_SYMBOL(remap_vmalloc_range);
 void  __attribute__((weak)) vmalloc_sync_all(void)
 {
 }
+
+
+static int f(pte_t *pte, struct page *pmd_page, unsigned long addr, void *data)
+{
+	/* apply_to_page_range() does all the hard work. */
+	return 0;
+}
+
+/**
+ *	alloc_vm_area - allocate a range of kernel address space
+ *	@size:		size of the area
+ *	@returns:	NULL on failure, vm_struct on success
+ *
+ *	This function reserves a range of kernel address space, and
+ *	allocates pagetables to map that range.  No actual mappings
+ *	are created.  If the kernel address space is not shared
+ *	between processes, it syncs the pagetable across all
+ *	processes.
+ */
+struct vm_struct *alloc_vm_area(size_t size)
+{
+	struct vm_struct *area;
+
+	area = get_vm_area(size, VM_IOREMAP);
+	if (area == NULL)
+		return NULL;
+
+	/*
+	 * This ensures that page tables are constructed for this region
+	 * of kernel virtual address space and mapped into init_mm.
+	 */
+	if (apply_to_page_range(&init_mm, (unsigned long)area->addr,
+				area->size, f, NULL)) {
+		free_vm_area(area);
+		return NULL;
+	}
+
+	/* Make sure the pagetables are constructed in process kernel
+	   mappings */
+	vmalloc_sync_all();
+
+	return area;
+}
+EXPORT_SYMBOL_GPL(alloc_vm_area);
+
+void free_vm_area(struct vm_struct *area)
+{
+	struct vm_struct *ret;
+	ret = remove_vm_area(area->addr);
+	BUG_ON(ret != area);
+	kfree(area);
+}
+EXPORT_SYMBOL_GPL(free_vm_area);