powerpc: Rename struct vm_region to avoid conflict with NOMMU

Rename PowerPC's struct vm_region so that I can introduce my own
global version for NOMMU.  It's feasible that the PowerPC version may
wish to use my global one instead.

The NOMMU vm_region struct defines areas of the physical memory map
that are under mmap.  This may include chunks of RAM or regions of
memory mapped devices, such as flash.  It is also used to retain
copies of file content so that shareable private memory mappings of
files can be made.  As such, it may be compatible with what is
described in the banner comment for PowerPC's vm_region struct.
Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>

arch/powerpc/lib/dma-noncoherent.c

@@ -77,26 +77,26 @@ static DEFINE_SPINLOCK(consistent_lock);
  * the amount of RAM found at boot time.)  I would imagine that get_vm_area()
  * would have to initialise this each time prior to calling vm_region_alloc().
  */
-struct vm_region {
+struct ppc_vm_region {
 	struct list_head	vm_list;
 	unsigned long		vm_start;
 	unsigned long		vm_end;
 };
 
-static struct vm_region consistent_head = {
+static struct ppc_vm_region consistent_head = {
 	.vm_list	= LIST_HEAD_INIT(consistent_head.vm_list),
 	.vm_start	= CONSISTENT_BASE,
 	.vm_end		= CONSISTENT_END,
 };
 
-static struct vm_region *
-vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp)
+static struct ppc_vm_region *
+ppc_vm_region_alloc(struct ppc_vm_region *head, size_t size, gfp_t gfp)
 {
 	unsigned long addr = head->vm_start, end = head->vm_end - size;
 	unsigned long flags;
-	struct vm_region *c, *new;
+	struct ppc_vm_region *c, *new;
 
-	new = kmalloc(sizeof(struct vm_region), gfp);
+	new = kmalloc(sizeof(struct ppc_vm_region), gfp);
 	if (!new)
 		goto out;
 
@@ -130,9 +130,9 @@ vm_region_alloc(struct vm_region *head, size_t size, gfp_t gfp)
 	return NULL;
 }
 
-static struct vm_region *vm_region_find(struct vm_region *head, unsigned long addr)
+static struct ppc_vm_region *ppc_vm_region_find(struct ppc_vm_region *head, unsigned long addr)
 {
-	struct vm_region *c;
+	struct ppc_vm_region *c;
 
 	list_for_each_entry(c, &head->vm_list, vm_list) {
 		if (c->vm_start == addr)
@@ -151,7 +151,7 @@ void *
 __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp)
 {
 	struct page *page;
-	struct vm_region *c;
+	struct ppc_vm_region *c;
 	unsigned long order;
 	u64 mask = 0x00ffffff, limit; /* ISA default */
 
@@ -191,7 +191,7 @@ __dma_alloc_coherent(size_t size, dma_addr_t *handle, gfp_t gfp)
 	/*
 	 * Allocate a virtual address in the consistent mapping region.
 	 */
-	c = vm_region_alloc(&consistent_head, size,
+	c = ppc_vm_region_alloc(&consistent_head, size,
 			    gfp & ~(__GFP_DMA | __GFP_HIGHMEM));
 	if (c) {
 		unsigned long vaddr = c->vm_start;
@@ -239,7 +239,7 @@ EXPORT_SYMBOL(__dma_alloc_coherent);
  */
 void __dma_free_coherent(size_t size, void *vaddr)
 {
-	struct vm_region *c;
+	struct ppc_vm_region *c;
 	unsigned long flags, addr;
 	pte_t *ptep;
 
@@ -247,7 +247,7 @@ void __dma_free_coherent(size_t size, void *vaddr)
 
 	spin_lock_irqsave(&consistent_lock, flags);
 
-	c = vm_region_find(&consistent_head, (unsigned long)vaddr);
+	c = ppc_vm_region_find(&consistent_head, (unsigned long)vaddr);
 	if (!c)
 		goto no_area;