[OpenBIOS] [PATCH v2] ppc: Use mtmsrd on ppc64

[Andreas Färber]

On ppc64 the mtmsr instruction only sets the low 32 bits of the MSR.
mtmsrd must be used to set the high bits such as Sixty-Four Bit Mode as well.

v2:
* Introduce MTMSRD macro as seen on Linux, suggested by Alex.
* Introduce inline functions {mfmsr,mtmsr}, suggested by Alex.

Cc: Alexander Graf <agraf at suse.de>
Signed-off-by: Andreas Färber <andreas.faerber at web.de>
---
 Alex, mind to add your SoB for the functions? Thanks.
 
 arch/ppc/qemu/ofmem.c        |    6 ++----
 include/arch/ppc/asmdefs.h   |    2 ++
 include/arch/ppc/processor.h |   20 ++++++++++++++++++++
 3 files changed, 24 insertions(+), 4 deletions(-)

diff --git a/arch/ppc/qemu/ofmem.c b/arch/ppc/qemu/ofmem.c
index 6f2b86d..ac3e049 100644
--- a/arch/ppc/qemu/ofmem.c
+++ b/arch/ppc/qemu/ofmem.c
@@ -396,7 +396,7 @@ void
 setup_mmu( unsigned long ramsize )
 {
 	ofmem_t *ofmem;
-	unsigned long sdr1, sr_base, msr;
+	unsigned long sdr1, sr_base;
 	unsigned long hash_base;
 	unsigned long hash_mask = ~0x000fffffUL; /* alignment for ppc64 */
 	int i;
@@ -428,9 +428,7 @@ setup_mmu( unsigned long ramsize )
 
 	/* Enable MMU */
 
-	asm volatile("mfmsr %0" : "=r" (msr) : );
-	msr |= MSR_IR | MSR_DR;
-	asm volatile("mtmsr %0" :: "r" (msr) );
+	mtmsr(mfmsr() | MSR_IR | MSR_DR);
 }
 
 void
diff --git a/include/arch/ppc/asmdefs.h b/include/arch/ppc/asmdefs.h
index 4e22156..51570ea 100644
--- a/include/arch/ppc/asmdefs.h
+++ b/include/arch/ppc/asmdefs.h
@@ -90,8 +90,10 @@
 
 #ifdef __powerpc64__
 #define RFI rfid
+#define MTMSRD(r) mtmsrd r
 #else
 #define RFI rfi
+#define MTMSRD(r) mtmsr  r
 #endif
 
 #ifndef __darwin__
diff --git a/include/arch/ppc/processor.h b/include/arch/ppc/processor.h
index 3afb03f..c7d5be6 100644
--- a/include/arch/ppc/processor.h
+++ b/include/arch/ppc/processor.h
@@ -403,8 +403,28 @@
 
 /* C helpers */
 
+#ifndef __ASSEMBLER__
+
 #define __stringify_1(x)	#x
 #define __stringify(x)		__stringify_1(x)
 #define mtspr(rn, v)		asm volatile("mtspr " __stringify(rn) ",%0" : : "r" (v))
 
+static inline unsigned long mfmsr(void)
+{
+    unsigned long msr;
+    asm volatile("mfmsr %0" : "=r" (msr));
+    return msr;
+}
+
+static inline void mtmsr(unsigned long msr)
+{
+#ifdef __powerpc64__
+    asm volatile("mtmsrd %0" :: "r" (msr));
+#else
+    asm volatile("mtmsr  %0" :: "r" (msr));
+#endif
+}
+
+#endif /* !__ASSEMBLER__ */
+
 #endif   /* _H_PROCESSOR */
-- 
1.7.3