X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?a=blobdiff_plain;f=arch%2Fx86_64%2Fmm%2Fioremap.c;h=45d7d823c3b85c91dab6740e30278fd0caa628ae;hb=f17a2686b11453680e9662ef8bdc8d948d0dce18;hp=ecf7acb5db9b4b0a8f744e0665d089bb7a040d78;hpb=7079060f3e86ea4c1d4e9c1e356592ef9dcaaa1f;p=pandora-kernel.git

diff --git a/arch/x86_64/mm/ioremap.c b/arch/x86_64/mm/ioremap.c
index ecf7acb5db9b..45d7d823c3b8 100644
--- a/arch/x86_64/mm/ioremap.c
+++ b/arch/x86_64/mm/ioremap.c
@@ -11,6 +11,7 @@
 #include <linux/vmalloc.h>
 #include <linux/init.h>
 #include <linux/slab.h>
+#include <linux/module.h>
 #include <asm/io.h>
 #include <asm/pgalloc.h>
 #include <asm/fixmap.h>
@@ -219,6 +220,7 @@ void __iomem * __ioremap(unsigned long phys_addr, unsigned long size, unsigned l
 	}
 	return (__force void __iomem *) (offset + (char *)addr);
 }
+EXPORT_SYMBOL(__ioremap);
 
 /**
  * ioremap_nocache     -   map bus memory into CPU space
@@ -246,10 +248,17 @@ void __iomem *ioremap_nocache (unsigned long phys_addr, unsigned long size)
 {
 	return __ioremap(phys_addr, size, _PAGE_PCD);
 }
+EXPORT_SYMBOL(ioremap_nocache);
 
+/**
+ * iounmap - Free a IO remapping
+ * @addr: virtual address from ioremap_*
+ *
+ * Caller must ensure there is only one unmapping for the same pointer.
+ */
 void iounmap(volatile void __iomem *addr)
 {
-	struct vm_struct *p;
+	struct vm_struct *p, *o;
 
 	if (addr <= high_memory) 
 		return; 
@@ -257,12 +266,33 @@ void iounmap(volatile void __iomem *addr)
 		addr < phys_to_virt(ISA_END_ADDRESS))
 		return;
 
-	write_lock(&vmlist_lock);
-	p = __remove_vm_area((void *)((unsigned long)addr & PAGE_MASK));
-	if (!p)
+	addr = (volatile void __iomem *)(PAGE_MASK & (unsigned long __force)addr);
+	/* Use the vm area unlocked, assuming the caller
+	   ensures there isn't another iounmap for the same address
+	   in parallel. Reuse of the virtual address is prevented by
+	   leaving it in the global lists until we're done with it.
+	   cpa takes care of the direct mappings. */
+	read_lock(&vmlist_lock);
+	for (p = vmlist; p; p = p->next) {
+		if (p->addr == addr)
+			break;
+	}
+	read_unlock(&vmlist_lock);
+
+	if (!p) {
 		printk("iounmap: bad address %p\n", addr);
-	else if (p->flags >> 20)
+		dump_stack();
+		return;
+	}
+
+	/* Reset the direct mapping. Can block */
+	if (p->flags >> 20)
 		ioremap_change_attr(p->phys_addr, p->size, 0);
-	write_unlock(&vmlist_lock);
+
+	/* Finally remove it */
+	o = remove_vm_area((void *)addr);
+	BUG_ON(p != o || o == NULL);
 	kfree(p); 
 }
+EXPORT_SYMBOL(iounmap);
+