From 8c36f4fc6e05d1b8b5a74b95e524410f1f501280 Mon Sep 17 00:00:00 2001
From: Keith Packard <keithp@keithp.com>
Date: Mon, 3 Nov 2008 18:21:45 +0100
Subject: [PATCH] --- yaml --- r: 118385 b: refs/heads/master c:
 e5beae16901795223d677f15aa2fe192976278ee h: refs/heads/master i:   118383:
 1758958c556386588650d8a31af5b8395284c73b v: v3

---
 [refs]                           |  2 +-
 trunk/arch/x86/Kconfig           |  4 +++
 trunk/include/linux/io-mapping.h | 43 +++++++++++++++++++-------------
 3 files changed, 30 insertions(+), 19 deletions(-)

diff --git a/[refs] b/[refs]
index 8bebeefbd16c..8129b2b0cfde 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: 8d5c6603c408d91ecf543f244f10ccb8b500ad95
+refs/heads/master: e5beae16901795223d677f15aa2fe192976278ee
diff --git a/trunk/arch/x86/Kconfig b/trunk/arch/x86/Kconfig
index 6f20718d3156..e60c59b81bdd 100644
--- a/trunk/arch/x86/Kconfig
+++ b/trunk/arch/x86/Kconfig
@@ -1894,6 +1894,10 @@ config SYSVIPC_COMPAT
 endmenu
 
 
+config HAVE_ATOMIC_IOMAP
+	def_bool y
+	depends on X86_32
+
 source "net/Kconfig"
 
 source "drivers/Kconfig"
diff --git a/trunk/include/linux/io-mapping.h b/trunk/include/linux/io-mapping.h
index 1b566993db6e..82df31726a54 100644
--- a/trunk/include/linux/io-mapping.h
+++ b/trunk/include/linux/io-mapping.h
@@ -33,86 +33,93 @@
 /* this struct isn't actually defined anywhere */
 struct io_mapping;
 
-#ifdef CONFIG_X86_64
+#ifdef CONFIG_HAVE_ATOMIC_IOMAP
+
+/*
+ * For small address space machines, mapping large objects
+ * into the kernel virtual space isn't practical. Where
+ * available, use fixmap support to dynamically map pages
+ * of the object at run time.
+ */
 
-/* Create the io_mapping object*/
 static inline struct io_mapping *
 io_mapping_create_wc(unsigned long base, unsigned long size)
 {
-	return (struct io_mapping *) ioremap_wc(base, size);
+	return (struct io_mapping *) base;
 }
 
 static inline void
 io_mapping_free(struct io_mapping *mapping)
 {
-	iounmap(mapping);
 }
 
 /* Atomic map/unmap */
 static inline void *
 io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset)
 {
-	return ((char *) mapping) + offset;
+	offset += (unsigned long) mapping;
+	return iomap_atomic_prot_pfn(offset >> PAGE_SHIFT, KM_USER0,
+				     __pgprot(__PAGE_KERNEL_WC));
 }
 
 static inline void
 io_mapping_unmap_atomic(void *vaddr)
 {
+	iounmap_atomic(vaddr, KM_USER0);
 }
 
-/* Non-atomic map/unmap */
 static inline void *
 io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
 {
-	return ((char *) mapping) + offset;
+	offset += (unsigned long) mapping;
+	return ioremap_wc(offset, PAGE_SIZE);
 }
 
 static inline void
 io_mapping_unmap(void *vaddr)
 {
+	iounmap(vaddr);
 }
 
-#endif /* CONFIG_X86_64 */
+#else
 
-#ifdef CONFIG_X86_32
+/* Create the io_mapping object*/
 static inline struct io_mapping *
 io_mapping_create_wc(unsigned long base, unsigned long size)
 {
-	return (struct io_mapping *) base;
+	return (struct io_mapping *) ioremap_wc(base, size);
 }
 
 static inline void
 io_mapping_free(struct io_mapping *mapping)
 {
+	iounmap(mapping);
 }
 
 /* Atomic map/unmap */
 static inline void *
 io_mapping_map_atomic_wc(struct io_mapping *mapping, unsigned long offset)
 {
-	offset += (unsigned long) mapping;
-	return iomap_atomic_prot_pfn(offset >> PAGE_SHIFT, KM_USER0,
-				     __pgprot(__PAGE_KERNEL_WC));
+	return ((char *) mapping) + offset;
 }
 
 static inline void
 io_mapping_unmap_atomic(void *vaddr)
 {
-	iounmap_atomic(vaddr, KM_USER0);
 }
 
+/* Non-atomic map/unmap */
 static inline void *
 io_mapping_map_wc(struct io_mapping *mapping, unsigned long offset)
 {
-	offset += (unsigned long) mapping;
-	return ioremap_wc(offset, PAGE_SIZE);
+	return ((char *) mapping) + offset;
 }
 
 static inline void
 io_mapping_unmap(void *vaddr)
 {
-	iounmap(vaddr);
 }
-#endif /* CONFIG_X86_32 */
+
+#endif /* HAVE_ATOMIC_IOMAP */
 
 #endif /* _LINUX_IO_MAPPING_H */