parisc: Fix vmap memory leak in ioremap()/iounmap()

Sven noticed that calling ioremap() and iounmap() multiple times leads
to a vmap memory leak:
	vmap allocation for size 4198400 failed:
	use vmalloc=<size> to increase size

It seems we missed calling vunmap() in iounmap().
Signed-off-by: Helge Deller <deller@gmx.de>
Noticed-by: Sven Schnelle <svens@stackframe.org>
Cc: <stable@vger.kernel.org> # v3.16+

arch/parisc/mm/ioremap.c

@@ -3,7 +3,7 @@
  * arch/parisc/mm/ioremap.c
  *
  * (C) Copyright 1995 1996 Linus Torvalds
- * (C) Copyright 2001-2006 Helge Deller <deller@gmx.de>
+ * (C) Copyright 2001-2019 Helge Deller <deller@gmx.de>
  * (C) Copyright 2005 Kyle McMartin <kyle@parisc-linux.org>
  */
 
@@ -84,7 +84,7 @@ void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned l
 	addr = (void __iomem *) area->addr;
 	if (ioremap_page_range((unsigned long)addr, (unsigned long)addr + size,
 			       phys_addr, pgprot)) {
-		vfree(addr);
+		vunmap(addr);
 		return NULL;
 	}
 
@@ -92,9 +92,11 @@ void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned l
 }
 EXPORT_SYMBOL(__ioremap);
 
-void iounmap(const volatile void __iomem *addr)
+void iounmap(const volatile void __iomem *io_addr)
 {
-	if (addr > high_memory)
-		return vfree((void *) (PAGE_MASK & (unsigned long __force) addr));
+	unsigned long addr = (unsigned long)io_addr & PAGE_MASK;
+
+	if (is_vmalloc_addr((void *)addr))
+		vunmap((void *)addr);
 }
 EXPORT_SYMBOL(iounmap);