ARM: simplify __iounmap() when dealing with section based mapping

[pandora-kernel.git] / arch / arm / mm / ioremap.c

diff --git a/arch/arm/mm/ioremap.c b/arch/arm/mm/ioremap.c
index d1f78ba..87c8afc 100644 (file)
--- a/arch/arm/mm/ioremap.c
+++ b/arch/arm/mm/ioremap.c
@@ -323,26 +323,24 @@ void __iounmap(volatile void __iomem *io_addr)
 {
        void *addr = (void *)(PAGE_MASK & (unsigned long)io_addr);
 #if !defined(CONFIG_SMP) && !defined(CONFIG_ARM_LPAE)
-       struct vm_struct **p, *tmp;
+       struct vm_struct *vm;
 
        /*
         * If this is a section based mapping we need to handle it
         * specially as the VM subsystem does not know how to handle
-        * such a beast. We need the lock here b/c we need to clear
-        * all the mappings before the area can be reclaimed
-        * by someone else.
+        * such a beast.
         */
-       write_lock(&vmlist_lock);
-       for (p = &vmlist ; (tmp = *p) ; p = &tmp->next) {
-               if ((tmp->flags & VM_IOREMAP) && (tmp->addr == addr)) {
-                       if (tmp->flags & VM_ARM_SECTION_MAPPING) {
-                               unmap_area_sections((unsigned long)tmp->addr,
-                                                   tmp->size);
+       read_lock(&vmlist_lock);
+       for (vm = vmlist; vm; vm = vm->next) {
+               if ((vm->flags & VM_IOREMAP) && (vm->addr == addr)) {
+                       if (vm->flags & VM_ARM_SECTION_MAPPING) {
+                               unmap_area_sections((unsigned long)vm->addr,
+                                                   vm->size);
                        }
                        break;
                }
        }
-       write_unlock(&vmlist_lock);
+       read_unlock(&vmlist_lock);
 #endif
 
        vunmap(addr);