[PATCH 1/4] ARM: versatile: support no-MMU mode addressing

Greg Ungerer gerg at uclinux.org
Tue Dec 6 22:08:29 PST 2016


Currently for the versatile boards the IO_ADDRESS() macro applies static
virtual address mapping for built-in IO devices. When operating without
the MMU enabled IO devices are accessed at their physical address, no
address translation is required.

For the !CONFIG_MMU case then define the IO_ADDRESS() macro to return the
physical address.

Signed-off-by: Greg Ungerer <gerg at uclinux.org>
---
 arch/arm/mach-versatile/versatile_dt.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/arch/arm/mach-versatile/versatile_dt.c b/arch/arm/mach-versatile/versatile_dt.c
index 3c8d39c..8cfa05a 100644
--- a/arch/arm/mach-versatile/versatile_dt.c
+++ b/arch/arm/mach-versatile/versatile_dt.c
@@ -37,7 +37,11 @@
 #include <asm/mach/map.h>
 
 /* macro to get at MMIO space when running virtually */
+#ifdef CONFIG_MMU
 #define IO_ADDRESS(x)		(((x) & 0x0fffffff) + (((x) >> 4) & 0x0f000000) + 0xf0000000)
+#else
+#define IO_ADDRESS(x)		(x)
+#endif
 #define __io_address(n)		((void __iomem __force *)IO_ADDRESS(n))
 
 /*
-- 
1.9.1




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