[PATCH V2] x86/intel_rdt: Implement show_options() for resctrlfs

[Shaohua Li <shli@fb.com>]

Implement show_options() callback for intel resource control filesystem
to expose the active mount options in /proc/

This applies to tip tree x86/cache branch.

Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Shaohua Li <shli@fb.com>
---
 arch/x86/kernel/cpu/intel_rdt_rdtgroup.c | 12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
index 1afd3f3..8af04af 100644
--- a/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
+++ b/arch/x86/kernel/cpu/intel_rdt_rdtgroup.c
@@ -1036,9 +1036,17 @@ static int rdtgroup_rmdir(struct kernfs_node *kn)
 	return ret;
 }
 
+static int rdtgroup_show_options(struct seq_file *seq, struct kernfs_root *kf)
+{
+	if (rdt_resources_all[RDT_RESOURCE_L3DATA].enabled)
+		seq_puts(seq, ",cdp");
+	return 0;
+}
+
 static struct kernfs_syscall_ops rdtgroup_kf_syscall_ops = {
-	.mkdir	= rdtgroup_mkdir,
-	.rmdir	= rdtgroup_rmdir,
+	.mkdir		= rdtgroup_mkdir,
+	.rmdir		= rdtgroup_rmdir,
+	.show_options	= rdtgroup_show_options,
 };
 
 static int __init rdtgroup_setup_root(void)
-- 
2.9.3