[PATCH 1/2] MIPS: Fixup and cleanup of TO_PHYS(), TO_CAC(), TO_UNCAC()

[Wu Zhangjin <wuzhangjin@gmail.com>]

From: Wu Zhangjin <wuzhangjin@gmail.com>

This patch fixes the TO_UNCAC() interface of 64bit kernel, the
TO_UNCAC(0xffffffff80000000) should yield 0x9000000000000000, but the
old TO_UNCAC() yield 0x97ffffff80000100 and make the kernel stop booting
with a bad address exception.

BTW, to share the same interface and remove the awful #ifdef, this patch
also provide the TO_PHYS(), TO_CAC(), TO_UNCAC() interfaces for the
32bit kernel, then we can substitue TO_UNCAC() for lots of old
KSEG1ADDR().

Thanks very much to Ralf, David, Thomas Bogendoerfer and post@pfrst.de for
their feedbacks of the following bug report:
http://www.linux-mips.org/archives/linux-mips/2010-04/msg00055.html

This patch is almost based on their feedbacks.

Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
---
 arch/mips/include/asm/addrspace.h           |   13 +++++++++++++
 arch/mips/include/asm/mach-generic/spaces.h |    8 ++++----
 2 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/arch/mips/include/asm/addrspace.h 
b/arch/mips/include/asm/addrspace.h
index 569f80a..58c3fe7 100644
--- a/arch/mips/include/asm/addrspace.h
+++ b/arch/mips/include/asm/addrspace.h
@@ -136,6 +136,19 @@
  */
 #define TO_PHYS_MASK   _CONST64_(0x07ffffffffffffff)   /* 2^^59 - 1 */
 
+#ifdef CONFIG_64BIT
+#define kernel_physaddr(x) ({ \
+       u64 a = (u64)(x); \
+       if ((a & CKSEG0) == CKSEG0) \
+               a = CPHYSADDR(a); \
+       else \
+               a &= TO_PHYS_MASK; \
+       a; \
+})
+#else
+#define kernel_physaddr        CPHYSADDR
+#endif
+
 #ifndef CONFIG_CPU_R8000
 
 /*
diff --git a/arch/mips/include/asm/mach-generic/spaces.h 
b/arch/mips/include/asm/mach-generic/spaces.h
index c9fa4b1..710f160 100644
--- a/arch/mips/include/asm/mach-generic/spaces.h
+++ b/arch/mips/include/asm/mach-generic/spaces.h
@@ -69,12 +69,12 @@
 #define HIGHMEM_START          (_AC(1, UL) << _AC(59, UL))
 #endif
 
-#define TO_PHYS(x)             (             ((x) & TO_PHYS_MASK))
-#define TO_CAC(x)              (CAC_BASE   | ((x) & TO_PHYS_MASK))
-#define TO_UNCAC(x)            (UNCAC_BASE | ((x) & TO_PHYS_MASK))
-
 #endif /* CONFIG_64BIT */
 
+#define TO_PHYS(x)             kernel_physaddr(x)
+#define TO_CAC(x)              (CAC_BASE   | kernel_physaddr(x))
+#define TO_UNCAC(x)            (UNCAC_BASE | kernel_physaddr(x))
+
 /*
  * This handles the memory map.
  */
-- 
1.7.0