MIPS: MT: proc: Add support for printing VPE and TC ids

And there are more CPUs or configurations that want to provide special
per-CPU information in /proc/cpuinfo.  So I think there needs to be a
hook mechanism, such as a notifier.

This is a first cut only; I need to think about what sort of looking
the notifier needs to have.  But I'd appreciate testing on MT hardware!

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Cc: Markos Chandras <markos.chandras@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/6066/

1 files changed, 22 insertions, 0 deletions

diff --git a/arch/mips/kernel/smp-mt.c b/arch/mips/kernel/smp-mt.c
index 0fb8cefc911..3378c452e5d 100644
--- a/arch/mips/kernel/smp-mt.c
+++ b/arch/mips/kernel/smp-mt.c
@@ -313,3 +313,25 @@ struct plat_smp_ops vsmp_smp_ops = {
 	.smp_setup		= vsmp_smp_setup,
 	.prepare_cpus		= vsmp_prepare_cpus,
 };
+
+static int proc_cpuinfo_chain_call(struct notifier_block *nfb,
+	unsigned long action_unused, void *data)
+{
+	struct proc_cpuinfo_notifier_args *pcn = data;
+	struct seq_file *m = pcn->m;
+	unsigned long n = pcn->n;
+
+	if (!cpu_has_mipsmt)
+		return NOTIFY_OK;
+
+	seq_printf(m, "VPE\t\t\t: %d\n", cpu_data[n].vpe_id);
+
+	return NOTIFY_OK;
+}
+
+static int __init proc_cpuinfo_notifier_init(void)
+{
+	return proc_cpuinfo_notifier(proc_cpuinfo_chain_call, 0);
+}
+
+subsys_initcall(proc_cpuinfo_notifier_init);