[PATCH] ia64: ioremap: check EFI for valid memory attributes

Check the EFI memory map so we can use the correct memory attributes for
ioremap().  Previously, we always used uncacheable access, which blows up on
some machines for regular system memory.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Matt Domsch <Matt_Domsch@dell.com>
Cc: "Tolentino, Matthew E" <matthew.e.tolentino@intel.com>
Cc: "Brown, Len" <len.brown@intel.com>
Cc: Andi Kleen <ak@muc.de>
Acked-by: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

arch/ia64/mm/Makefile

@@ -2,7 +2,7 @@
 # Makefile for the ia64-specific parts of the memory manager.
 #
 
-obj-y := init.o fault.o tlb.o extable.o
+obj-y := init.o fault.o tlb.o extable.o ioremap.o
 
 obj-$(CONFIG_HUGETLB_PAGE) += hugetlbpage.o
 obj-$(CONFIG_NUMA)	   += numa.o

arch/ia64/mm/ioremap.c

@@ -0,0 +1,43 @@
+/*
+ * (c) Copyright 2006 Hewlett-Packard Development Company, L.P.
+ *	Bjorn Helgaas <bjorn.helgaas@hp.com>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ */
+
+#include <linux/compiler.h>
+#include <linux/module.h>
+#include <linux/efi.h>
+#include <asm/io.h>
+
+static inline void __iomem *
+__ioremap (unsigned long offset, unsigned long size)
+{
+	return (void __iomem *) (__IA64_UNCACHED_OFFSET | offset);
+}
+
+void __iomem *
+ioremap (unsigned long offset, unsigned long size)
+{
+	if (efi_mem_attribute_range(offset, size, EFI_MEMORY_UC))
+		return __ioremap(offset, size);
+
+	if (efi_mem_attribute_range(offset, size, EFI_MEMORY_WB))
+		return phys_to_virt(offset);
+
+	/*
+	 * Someday this should check ACPI resources so we
+	 * can do the right thing for hot-plugged regions.
+	 */
+	return __ioremap(offset, size);
+}
+EXPORT_SYMBOL(ioremap);
+
+void __iomem *
+ioremap_nocache (unsigned long offset, unsigned long size)
+{
+	return __ioremap(offset, size);
+}
+EXPORT_SYMBOL(ioremap_nocache);

include/asm-ia64/io.h

@@ -416,25 +416,14 @@ __writeq (unsigned long val, volatile void __iomem *addr)
 # define outl_p		outl
 #endif
 
-/*
- * An "address" in IO memory space is not clearly either an integer or a pointer. We will
- * accept both, thus the casts.
- *
- * On ia-64, we access the physical I/O memory space through the uncached kernel region.
- */
-static inline void __iomem *
-ioremap (unsigned long offset, unsigned long size)
-{
-	return (void __iomem *) (__IA64_UNCACHED_OFFSET | (offset));
-}
+extern void __iomem * ioremap(unsigned long offset, unsigned long size);
+extern void __iomem * ioremap_nocache (unsigned long offset, unsigned long size);
 
 static inline void
 iounmap (volatile void __iomem *addr)
 {
 }
 
-#define ioremap_nocache(o,s)	ioremap(o,s)
-
 /* Use normal IO mappings for DMI */
 #define dmi_ioremap ioremap
 #define dmi_iounmap(x,l) iounmap(x)