MIPS: Add CPU cluster number accessors

Introduce cpu_cluster() & cpu_set_cluster() accessor functions in the
same vein as cpu_core(), cpu_vpe_id() & their set variants. These will
be used in further patches to allow users to get or set a CPUs cluster
number.
Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/17012/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/include/asm/cpu-info.h

@@ -139,6 +139,16 @@ struct proc_cpuinfo_notifier_args {
 	unsigned long n;
 };
 
+static inline unsigned int cpu_cluster(struct cpuinfo_mips *cpuinfo)
+{
+	/* Optimisation for systems where multiple clusters aren't used */
+	if (!IS_ENABLED(CONFIG_CPU_MIPSR6))
+		return 0;
+
+	return (cpuinfo->globalnumber & MIPS_GLOBALNUMBER_CLUSTER) >>
+		MIPS_GLOBALNUMBER_CLUSTER_SHF;
+}
+
 static inline unsigned int cpu_core(struct cpuinfo_mips *cpuinfo)
 {
 	return (cpuinfo->globalnumber & MIPS_GLOBALNUMBER_CORE) >>
@@ -155,6 +165,7 @@ static inline unsigned int cpu_vpe_id(struct cpuinfo_mips *cpuinfo)
 		MIPS_GLOBALNUMBER_VP_SHF;
 }
 
+extern void cpu_set_cluster(struct cpuinfo_mips *cpuinfo, unsigned int cluster);
 extern void cpu_set_core(struct cpuinfo_mips *cpuinfo, unsigned int core);
 extern void cpu_set_vpe_id(struct cpuinfo_mips *cpuinfo, unsigned int vpe);
 

arch/mips/kernel/cpu-probe.c

@@ -2099,6 +2099,16 @@ void cpu_report(void)
 		pr_info("MSA revision is: %08x\n", c->msa_id);
 }
 
+void cpu_set_cluster(struct cpuinfo_mips *cpuinfo, unsigned int cluster)
+{
+	/* Ensure the core number fits in the field */
+	WARN_ON(cluster > (MIPS_GLOBALNUMBER_CLUSTER >>
+			   MIPS_GLOBALNUMBER_CLUSTER_SHF));
+
+	cpuinfo->globalnumber &= ~MIPS_GLOBALNUMBER_CLUSTER;
+	cpuinfo->globalnumber |= cluster << MIPS_GLOBALNUMBER_CLUSTER_SHF;
+}
+
 void cpu_set_core(struct cpuinfo_mips *cpuinfo, unsigned int core)
 {
 	/* Ensure the core number fits in the field */