MIPS: mips-cm: Extend CM accessors for 64-bit CPUs

Previously, the CM accessors were only accessing CM registers as u32
types instead of using the native CM register with. However, newer CMs
may actually be 64-bit on MIPS64 cores. Fortunately, current 64-bit CMs
(CM3) hold all the useful configuration bits in the lower half of the
64-bit registers (at least most of them) so they can still be accessed
using the current 32-bit accessors.

Signed-off-by: Markos Chandras <markos.chandras@imgtec.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Jason Cooper <jason@lakedaemon.net>
Cc: Andrew Bresticker <abrestic@chromium.org>
Cc: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/10707/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/kernel/mips-cm.c

@@ -15,6 +15,7 @@
 
 void __iomem *mips_cm_base;
 void __iomem *mips_cm_l2sync_base;
+int mips_cm_is64;
 
 phys_addr_t __mips_cm_phys_base(void)
 {
@@ -124,5 +125,8 @@ int mips_cm_probe(void)
 	/* probe for an L2-only sync region */
 	mips_cm_probe_l2sync();
 
+	/* determine register width for this CM */
+	mips_cm_is64 = config_enabled(CONFIG_64BIT) && (mips_cm_revision() >= CM_REV_CM3);
+
 	return 0;
 }