sh: Handle early ioremaps through fixed mappings.

This adds in a mem_init_done to work out when a standard ioremap() is
possible, falling back to the fixmap based ioremap otherwise.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>

3 files changed, 16 insertions, 3 deletions

diff --git a/arch/sh/include/asm/processor.h b/arch/sh/include/asm/processor.h
index 017e0c1807b2..a522e5d8f44f 100644
--- a/arch/sh/include/asm/processor.h
+++ b/arch/sh/include/asm/processor.h
@@ -101,6 +101,9 @@ struct seq_operations;
 
 extern struct pt_regs fake_swapper_regs;
 
+/* arch/sh/mm/init.c */
+extern unsigned int mem_init_done;
+
 /* arch/sh/kernel/setup.c */
 const char *get_cpu_subtype(struct sh_cpuinfo *c);
 extern const struct seq_operations cpuinfo_op;
diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c
index 30a9b530d456..fe578a286fdd 100644
--- a/arch/sh/mm/init.c
+++ b/arch/sh/mm/init.c
@@ -237,6 +237,8 @@ static void __init iommu_init(void)
         no_iommu_init();
 }
 
+unsigned int mem_init_done = 0;
+
 void __init mem_init(void)
 {
         int codesize, datasize, initsize;
@@ -287,6 +289,8 @@ void __init mem_init(void)
 
         /* Initialize the vDSO */
         vsyscall_init();
+
+        mem_init_done = 1;
 }
 
 void free_initmem(void)
diff --git a/arch/sh/mm/ioremap_32.c b/arch/sh/mm/ioremap_32.c
index c80a8166fbb0..24f6ba6bff71 100644
--- a/arch/sh/mm/ioremap_32.c
+++ b/arch/sh/mm/ioremap_32.c
@@ -1,13 +1,13 @@
 /*
  * arch/sh/mm/ioremap.c
  *
+ * (C) Copyright 1995 1996 Linus Torvalds
+ * (C) Copyright 2005 - 2010  Paul Mundt
+ *
  * Re-map IO memory to kernel address space so that we can access it.
  * This is needed for high PCI addresses that aren't mapped in the
  * 640k-1MB IO memory area on PC's
  *
- * (C) Copyright 1995 1996 Linus Torvalds
- * (C) Copyright 2005, 2006 Paul Mundt
- *
  * This file is subject to the terms and conditions of the GNU General
  * Public License. See the file "COPYING" in the main directory of this
  * archive for more details.
@@ -65,6 +65,12 @@ void __iomem *__ioremap_caller(unsigned long phys_addr, unsigned long size,
         size = PAGE_ALIGN(last_addr+1) - phys_addr;
 
         /*
+         * If we can't yet use the regular approach, go the fixmap route.
+         */
+        if (!mem_init_done)
+                return ioremap_fixed(phys_addr, size, __pgprot(flags));
+
+        /*
          * Ok, go for it..
          */
         area = get_vm_area_caller(size, VM_IOREMAP, caller);