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authorMatt Fleming <matt@console-pimps.org>2009-11-05 07:54:17 +0000
committerMatt Fleming <matt@console-pimps.org>2010-01-16 14:31:36 +0000
commit4d35b93a66e9b87df20784fcf130d2e8760be53f (patch)
treeaf0b82ab28a0e4142130c6510cc06cca3d4a67aa /arch/sh/include
parent07cad4dc1bfdaefd20c6329e9d8179ad1c600e92 (diff)
sh: Add fixed ioremap support
Some devices need to be ioremap'd and accessed very early in the boot process. It is not possible to use the standard ioremap() function in this case because that requires kmalloc()'ing some virtual address space and kmalloc() may not be available so early in boot. This patch provides fixmap mappings that allow physical address ranges to be remapped into the kernel address space during the early boot stages. Signed-off-by: Matt Fleming <matt@console-pimps.org>
Diffstat (limited to 'arch/sh/include')
-rw-r--r--arch/sh/include/asm/fixmap.h8
-rw-r--r--arch/sh/include/asm/io.h6
2 files changed, 14 insertions, 0 deletions
diff --git a/arch/sh/include/asm/fixmap.h b/arch/sh/include/asm/fixmap.h
index 1566d3361ca..38a1de86687 100644
--- a/arch/sh/include/asm/fixmap.h
+++ b/arch/sh/include/asm/fixmap.h
@@ -60,6 +60,14 @@ enum fixed_addresses {
FIX_KMAP_BEGIN, /* reserved pte's for temporary kernel mappings */
FIX_KMAP_END = FIX_KMAP_BEGIN+(KM_TYPE_NR*NR_CPUS)-1,
#endif
+ /*
+ * FIX_IOREMAP entries are useful for mapping physical address
+ * space before ioremap() is useable, e.g. really early in boot
+ * before kmalloc() is working.
+ */
+#define FIX_N_IOREMAPS 32
+ FIX_IOREMAP_BEGIN,
+ FIX_IOREMAP_END = FIX_IOREMAP_BEGIN + FIX_N_IOREMAPS,
__end_of_fixed_addresses
};
diff --git a/arch/sh/include/asm/io.h b/arch/sh/include/asm/io.h
index f4314d8b05b..bee5965e0a8 100644
--- a/arch/sh/include/asm/io.h
+++ b/arch/sh/include/asm/io.h
@@ -237,6 +237,12 @@ void __iomem *__ioremap_caller(unsigned long offset, unsigned long size,
unsigned long flags, void *caller);
void __iounmap(void __iomem *addr);
+#ifdef CONFIG_IOREMAP_FIXED
+extern void __iomem *ioremap_fixed(resource_size_t, unsigned long, pgprot_t);
+extern void iounmap_fixed(void __iomem *);
+extern void ioremap_fixed_init(void);
+#endif
+
static inline void __iomem *
__ioremap(unsigned long offset, unsigned long size, unsigned long flags)
{