MIPS: Allow read64 GCR accessors to work on MIPS32 kernels

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>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Cc: James Hogan <james.hogan@imgtec.com>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Patchwork: https://patchwork.linux-mips.org/patch/11188/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

diff --git a/arch/mips/include/asm/mips-cm.h b/arch/mips/include/asm/mips-cm.h
index 465a7c1..7234fb7 100644 (file)
--- 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)              \