x86/resctrl: Display CLOSID for resource group

In x86, hardware uses CLOSID to identify a control group. When a user
creates a control group this information is not visible to the user. It
can help resctrl debugging.

Add CLOSID(ctrl_hw_id) to the control groups display in the resctrl
interface. Users can see this detail when resctrl is mounted with the
"-o debug" option.

Other architectures do not use "CLOSID". Use the names ctrl_hw_id to refer
to "CLOSID" in an effort to keep the naming generic.

For example:
  $cat /sys/fs/resctrl/ctrl_grp1/ctrl_hw_id
  1

Signed-off-by: Babu Moger <babu.moger@amd.com>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Reviewed-by: Peter Newman <peternewman@google.com>
Reviewed-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Reviewed-by: Fenghua Yu <fenghua.yu@intel.com>
Reviewed-by: Reinette Chatre <reinette.chatre@intel.com>
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Tested-by: Peter Newman <peternewman@google.com>
Tested-by: Tan Shaopeng <tan.shaopeng@jp.fujitsu.com>
Link: https://lore.kernel.org/r/20231017002308.134480-8-babu.moger@amd.com

diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index 68f11611f3416cef47e06146bdecc84570d0b50b..7412252f95a7d48d20af88c478b44dde8f95f66d 100644 (file)
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -359,6 +359,10 @@ When control is enabled all CTRL_MON groups will also contain:
        file. On successful pseudo-locked region creation the mode will
        automatically change to "pseudo-locked".
 
+"ctrl_hw_id":
+       Available only with debug option. The identifier used by hardware
+       for the control group. On x86 this is the CLOSID.
+
 When monitoring is enabled all MON groups will also contain:
 
 "mon_data":

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index 84e0f45578dd5f1de9ddaa443bf9cec258ccede3..5814a0bf3cea7a1ce2aec45485d8c0fcbb270fca 100644 (file)
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -779,6 +779,22 @@ static int rdtgroup_tasks_show(struct kernfs_open_file *of,
        return ret;
 }
 
+static int rdtgroup_closid_show(struct kernfs_open_file *of,
+                               struct seq_file *s, void *v)
+{
+       struct rdtgroup *rdtgrp;
+       int ret = 0;
+
+       rdtgrp = rdtgroup_kn_lock_live(of->kn);
+       if (rdtgrp)
+               seq_printf(s, "%u\n", rdtgrp->closid);
+       else
+               ret = -ENOENT;
+       rdtgroup_kn_unlock(of->kn);
+
+       return ret;
+}
+
 #ifdef CONFIG_PROC_CPU_RESCTRL
 
 /*
@@ -1881,6 +1897,13 @@ static struct rftype res_common_files[] = {
                .seq_show       = rdt_has_sparse_bitmasks_show,
                .fflags         = RFTYPE_CTRL_INFO | RFTYPE_RES_CACHE,
        },
+       {
+               .name           = "ctrl_hw_id",
+               .mode           = 0444,
+               .kf_ops         = &rdtgroup_kf_single_ops,
+               .seq_show       = rdtgroup_closid_show,
+               .fflags         = RFTYPE_CTRL_BASE | RFTYPE_DEBUG,
+       },
 
 };