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From: Babu Moger <babu.moger@amd.com>
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Subject: [RFC PATCH v3 16/17] x86/resctrl: Introduce interface to list assignment states of all the groups
Date: Thu, 28 Mar 2024 20:06:49 -0500
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Introduce rdtgroup_mbm_assign_control_show list assignment states of all the
resctrl groups.

List follows the following format:

- Default CTRL_MON group:
  "//<domain_id>=<assignment_flags>"

- Non-default CTRL_MON group:
  "<CTRL_MON group>//<domain_id>=<assignment_flags>"

- Child MON group of default CTRL_MON group:
  "/<MON group>/<domain_id>=<assignment_flags>"

- Child MON group of non-default CTRL_MON group:
  "<CTRL_MON group>/<MON group>/<domain_id>=<assignment_flags>"

Signed-off-by: Babu Moger <babu.moger@amd.com>
---
v3: New patch.
    Addresses the feedback to provide the global assignment interface.
    https://lore.kernel.org/lkml/c73f444b-83a1-4e9a-95d3-54c5165ee782@intel.com/
---
 Documentation/arch/x86/resctrl.rst     | 51 ++++++++++++++++
 arch/x86/kernel/cpu/resctrl/monitor.c  |  1 +
 arch/x86/kernel/cpu/resctrl/rdtgroup.c | 85 ++++++++++++++++++++++++++
 3 files changed, 137 insertions(+)

diff --git a/Documentation/arch/x86/resctrl.rst b/Documentation/arch/x86/resctrl.rst
index 3e441b828765..2d96565501ab 100644
--- a/Documentation/arch/x86/resctrl.rst
+++ b/Documentation/arch/x86/resctrl.rst
@@ -278,6 +278,57 @@ with the following files:
 	The number of assignable counters available when the assignable monitoring
 	feature is supported.
 
+"mbm_assign_control":
+	Available when assignable monitoring features are supported.
+	Reports the resctrl group and assignment status of each group.
+
+	List follows the following format:
+
+	* Default CTRL_MON group:
+		"//<domain_id>=<assignment_flags>"
+
+	* Non-default CTRL_MON group:
+		"<CTRL_MON group>//<domain_id>=<assignment_flags>"
+
+	* Child MON group of default CTRL_MON group:
+		"/<MON group>/<domain_id>=<assignment_flags>"
+
+	* Child MON group of non-default CTRL_MON group:
+		"<CTRL_MON group>/<MON group>/<domain_id>=<assignment_flags>"
+
+	Assignment flags can be one of the following:
+	::
+
+	 t  MBM total event is assigned
+	 l  MBM local event is assigned
+	 tl Both total and local MBM events are assigned
+	 _  None of the MBM events are assigned
+
+	Examples:
+	::
+
+	 # cat /sys/fs/resctrl/info/L3_MON/mbm_assign_control
+	 //0=tl;1=tl;
+	 /child_default_mon_grp/0=t;1=t;
+	 non_default_ctrl_mon_grp//0=l;1=l;
+	 non_default_ctrl_mon_grp/child_non_default_mon_grp/0=_;1=_;
+
+	 //0=tl;1=tl;
+	 Both the events on the default group are assigned.
+
+	 /child_default_mon_grp/0=t;1=t;
+	 Only total event on this mon group is assigned. This is a child
+	 monitor group of the default control mon group.
+
+	 non_default_ctrl_mon_grp//0=l;1=l;
+	 Only local event on this control mon group is assigned. This is a
+	 non default control mon group.
+
+	 non_default_ctrl_mon_grp/child_non_default_mon_grp/0=_;1=_;
+	 None of events are assigned on this mon group. This is a child
+	 monitor group of the non default control mon group.
+
+
 "max_threshold_occupancy":
 		Read/write file provides the largest value (in
 		bytes) at which a previously used LLC_occupancy
diff --git a/arch/x86/kernel/cpu/resctrl/monitor.c b/arch/x86/kernel/cpu/resctrl/monitor.c
index 8677dbf6de43..8a2e2afc85e8 100644
--- a/arch/x86/kernel/cpu/resctrl/monitor.c
+++ b/arch/x86/kernel/cpu/resctrl/monitor.c
@@ -1062,6 +1062,7 @@ int __init rdt_get_mon_l3_config(struct rdt_resource *r)
 			r->mbm_assign_capable = ABMC_ASSIGN;
 			resctrl_file_fflags_init("mbm_assign", RFTYPE_MON_INFO);
 			resctrl_file_fflags_init("mbm_assign_cntrs", RFTYPE_MON_INFO);
+			resctrl_file_fflags_init("mbm_assign_control", RFTYPE_MON_INFO);
 		}
 	}
 
diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index a6e0ef2631ae..9fd37b6c3b24 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -932,6 +932,85 @@ static ssize_t rdtgroup_mbm_assign_write(struct kernfs_open_file *of,
 	return ret ?: nbytes;
 }
 
+static char *mon_state_to_str(int mon_state, char *str)
+{
+	char *tmp = str;
+
+	switch (mon_state) {
+	case ASSIGN_NONE:
+		*tmp++ = '_';
+		break;
+	case (ASSIGN_TOTAL | ASSIGN_LOCAL):
+		*tmp++ = 't';
+		*tmp++ = 'l';
+		break;
+	case ASSIGN_TOTAL:
+		*tmp++ = 't';
+		break;
+	case ASSIGN_LOCAL:
+		*tmp++ = 'l';
+		break;
+	default:
+		break;
+	}
+
+	*tmp = '\0';
+	return str;
+}
+
+static int rdtgroup_mbm_assign_control_show(struct kernfs_open_file *of,
+					    struct seq_file *s, void *v)
+{
+	struct rdt_resource *r = of->kn->parent->priv;
+	struct rdt_hw_resource *hw_res = resctrl_to_arch_res(r);
+	struct rdt_domain *dom;
+	struct rdtgroup *rdtg;
+	int grp_default = 0;
+	char str[10];
+
+	if (!hw_res->abmc_enabled) {
+		rdt_last_cmd_puts("ABMC feature is not enabled\n");
+		return -EINVAL;
+	}
+
+	mutex_lock(&rdtgroup_mutex);
+
+	list_for_each_entry(rdtg, &rdt_all_groups, rdtgroup_list) {
+		struct rdtgroup *crg;
+
+		if (rdtg == &rdtgroup_default) {
+			grp_default = 1;
+			seq_puts(s, "//");
+		} else {
+			grp_default = 0;
+			seq_printf(s, "%s//", rdtg->kn->name);
+		}
+
+		list_for_each_entry(dom, &r->domains, list)
+			seq_printf(s, "%d=%s;", dom->id,
+				   mon_state_to_str(rdtg->mon.mon_state, str));
+		seq_putc(s, '\n');
+
+		list_for_each_entry(crg, &rdtg->mon.crdtgrp_list,
+				    mon.crdtgrp_list) {
+			if (grp_default)
+				seq_printf(s, "/%s/", crg->kn->name);
+			else
+				seq_printf(s, "%s/%s/", rdtg->kn->name,
+					   crg->kn->name);
+
+			list_for_each_entry(dom, &r->domains, list)
+				seq_printf(s, "%d=%s;", dom->id,
+					   mon_state_to_str(crg->mon.mon_state, str));
+			seq_putc(s, '\n');
+		}
+	}
+
+	mutex_unlock(&rdtgroup_mutex);
+
+	return 0;
+}
+
 static int rdtgroup_mbm_assign_cntrs_show(struct kernfs_open_file *of,
 					  struct seq_file *s, void *v)
 {
@@ -2119,6 +2198,12 @@ static struct rftype res_common_files[] = {
 		.seq_show	= rdtgroup_mbm_assign_show,
 		.write		= rdtgroup_mbm_assign_write,
 	},
+	{
+		.name		= "mbm_assign_control",
+		.mode		= 0444,
+		.kf_ops		= &rdtgroup_kf_single_ops,
+		.seq_show	= rdtgroup_mbm_assign_control_show,
+	},
 	{
 		.name		= "mbm_assign_cntrs",
 		.mode		= 0444,
-- 
2.34.1