linux-kernel - [PATCH v3 7/7] x86/resctrl: Add debug files when mounted with debug option

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Message-ID: <167778870823.1053859.9940104139782066465.stgit@bmoger-ubuntu>
Date:   Thu, 2 Mar 2023 14:25:08 -0600
From:   Babu Moger <babu.moger@....com>
To:     <corbet@....net>, <reinette.chatre@...el.com>,
        <tglx@...utronix.de>, <mingo@...hat.com>, <bp@...en8.de>
CC:     <fenghua.yu@...el.com>, <dave.hansen@...ux.intel.com>,
        <x86@...nel.org>, <hpa@...or.com>, <paulmck@...nel.org>,
        <akpm@...ux-foundation.org>, <quic_neeraju@...cinc.com>,
        <rdunlap@...radead.org>, <damien.lemoal@...nsource.wdc.com>,
        <songmuchun@...edance.com>, <peterz@...radead.org>,
        <jpoimboe@...nel.org>, <pbonzini@...hat.com>, <babu.moger@....com>,
        <chang.seok.bae@...el.com>, <pawan.kumar.gupta@...ux.intel.com>,
        <jmattson@...gle.com>, <daniel.sneddon@...ux.intel.com>,
        <sandipan.das@....com>, <tony.luck@...el.com>,
        <james.morse@....com>, <linux-doc@...r.kernel.org>,
        <linux-kernel@...r.kernel.org>, <bagasdotme@...il.com>,
        <eranian@...gle.com>, <christophe.leroy@...roup.eu>,
        <pawan.kumar.gupta@...ux.intel.com>, <jarkko@...nel.org>,
        <adrian.hunter@...el.com>, <quic_jiles@...cinc.com>,
        <peternewman@...gle.com>, <babu.moger@....com>
Subject: [PATCH v3 7/7] x86/resctrl: Add debug files when mounted with debug
 option

Add the debug files to the resctrl hierarchy.

Signed-off-by: Babu Moger <babu.moger@....com>
---
 arch/x86/kernel/cpu/resctrl/rdtgroup.c |   48 +++++++++++++++++++++++++++++++-
 1 file changed, 47 insertions(+), 1 deletion(-)

diff --git a/arch/x86/kernel/cpu/resctrl/rdtgroup.c b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
index a1f13715a65c..790c6b9f9031 100644
--- a/arch/x86/kernel/cpu/resctrl/rdtgroup.c
+++ b/arch/x86/kernel/cpu/resctrl/rdtgroup.c
@@ -2400,6 +2400,45 @@ static int mkdir_mondata_all(struct kernfs_node *parent_kn,
 			     struct rdtgroup *prgrp,
 			     struct kernfs_node **mon_data_kn);
 
+void resctrl_add_debug_file(struct kernfs_node *parent_kn, const char *config,
+			    unsigned long fflags)
+{
+	struct rftype *rft;
+
+	rft = rdtgroup_get_rftype_by_name(config);
+	if (rft) {
+		rft->fflags |= fflags;
+		rdtgroup_add_file(parent_kn, rft);
+	}
+}
+
+static void resctrl_add_debug_files(void)
+{
+	resctrl_add_debug_file(rdtgroup_default.kn, "rmid", RFTYPE_BASE);
+	resctrl_add_debug_file(rdtgroup_default.kn, "closid", RFTYPE_BASE_CTRL);
+	kernfs_activate(rdtgroup_default.kn);
+}
+
+void resctrl_remove_debug_file(struct kernfs_node *parent_kn,
+			       const char *config, unsigned long fflags)
+{
+	struct rftype *rft;
+
+	rft = rdtgroup_get_rftype_by_name(config);
+	if (rft) {
+		rft->fflags &= ~fflags;
+		kernfs_remove_by_name(parent_kn, config);
+	}
+}
+
+static void resctrl_remove_debug_files(void)
+{
+	resctrl_remove_debug_file(rdtgroup_default.kn, "rmid", RFTYPE_BASE);
+	resctrl_remove_debug_file(rdtgroup_default.kn, "closid",
+				  RFTYPE_BASE_CTRL);
+	kernfs_activate(rdtgroup_default.kn);
+}
+
 static int rdt_enable_ctx(struct rdt_fs_context *ctx)
 {
 	int ret = 0;
@@ -2413,8 +2452,10 @@ static int rdt_enable_ctx(struct rdt_fs_context *ctx)
 	if (!ret && ctx->enable_mba_mbps)
 		ret = set_mba_sc(true);
 
-	if (!ret && ctx->debug)
+	if (!ret && ctx->debug) {
 		resctrl_debug = true;
+		resctrl_add_debug_files();
+	}
 
 	return ret;
 }
@@ -2831,6 +2872,11 @@ static void rdt_kill_sb(struct super_block *sb)
 
 	set_mba_sc(false);
 
+	if (resctrl_debug) {
+		resctrl_remove_debug_files();
+		resctrl_debug = false;
+	}
+
 	/*Put everything back to default values. */
 	for_each_alloc_capable_rdt_resource(r)
 		reset_all_ctrls(r);