[PATCH 4/5] MIPS: allow read64 GCR accessors to work on MIPS32 kernels

[Paul Burton <paul.burton@imgtec.com>]

If we run a MIPS32 kernel on a system using CM3 we may still need to
access 64 bit GCRs, as will be done in later patches. Allow this by
having the read64_gcr_* accessor functions perform 2 x 32 bit reads on
those systems.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
---

 arch/mips/include/asm/mips-cm.h | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/arch/mips/include/asm/mips-cm.h b/arch/mips/include/asm/mips-cm.h
index 2a70b76..b9df4b2 100644
--- a/arch/mips/include/asm/mips-cm.h
+++ b/arch/mips/include/asm/mips-cm.h
@@ -125,7 +125,17 @@ static inline u32 read32_gcr_##name(void)			\
 								\
 static inline u64 read64_gcr_##name(void)			\
 {								\
-	return __raw_readq(addr_gcr_##name());			\
+	void __iomem *addr = addr_gcr_##name();			\
+	u64 ret;						\
+								\
+	if (mips_cm_is64) {					\
+		ret = __raw_readq(addr);			\
+	} else {						\
+		ret = __raw_readl(addr);			\
+		ret |= (u64)__raw_readl(addr + 0x4) << 32;	\
+	}							\
+								\
+	return ret;						\
 }								\
 								\
 static inline unsigned long read_gcr_##name(void)		\
-- 
2.5.3