[PATCH v3 44/46] perf/x86/intel/cmt: add debugfs intel_cmt directory

[David Carrillo-Cisneros <davidcc@google.com>]

Add debug fs to intel_cmt to help maintenance. It shows the following
human readable snapshots of the internals of the CMT driver:
  - hrchy: A per monr view of the monr hierarchy.
  - pkgs: A per-package view of all online struct pkg_data.
  - rmids: A per-package view of occupancy and state of all rmids.

Signed-off-by: David Carrillo-Cisneros <davidcc@google.com>
---
 arch/x86/events/intel/cmt.c | 385 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 385 insertions(+)

diff --git a/arch/x86/events/intel/cmt.c b/arch/x86/events/intel/cmt.c
index 8cbcbc6..554ebd2 100644
--- a/arch/x86/events/intel/cmt.c
+++ b/arch/x86/events/intel/cmt.c
@@ -2372,6 +2372,376 @@ static ssize_t max_recycle_threshold_store(struct device *dev,
 
 static DEVICE_ATTR_RW(max_recycle_threshold);
 
+
+#define INTEL_CMT_DEBUGFS
+
+#ifdef INTEL_CMT_DEBUGFS
+
+#include <linux/debugfs.h>
+
+#define DBG_PRINTF(format__, ...) \
+	seq_printf(s, "%*s" format__, 4 * pad, "", ##__VA_ARGS__)
+
+static void cmt_dbg_show__pmonr(struct seq_file *s,
+				struct pmonr *pmonr,
+				int pad)
+{
+	struct pmonr *pos;
+	union pmonr_rmids rmids;
+	static const char * const state_strs[] = {"OFF", "UNUSED", "ACTIVE",
+						  "DEP_IDLE", "DEP_DIRTY"};
+
+	DBG_PRINTF("pmonr: (%p, pkgid: %d, monr: %p)\n",
+			pmonr, pmonr->pkgd->pkgid, pmonr->monr);
+	pad++;
+
+	rmids.value = atomic64_read(&pmonr->atomic_rmids);
+	DBG_PRINTF("atomic_rmids: (%d,%d), state: %s, lender: %p\n",
+			rmids.sched_rmid, rmids.read_rmid,
+			state_strs[pmonr->state], pmonr->lender);
+
+	if (pmonr->state == PMONR_ACTIVE) {
+		DBG_PRINTF("pmonr_deps_head:");
+		list_for_each_entry(pos, &pmonr->pmonr_deps_head,
+				    pmonr_deps_entry) {
+			seq_printf(s, "%p,", pos);
+		}
+		seq_puts(s, "\n");
+	}
+
+	DBG_PRINTF("last_enter_active: %lu\n",
+			atomic64_read(&pmonr->last_enter_active));
+
+}
+
+static void cmt_dbg_show__monr(struct seq_file *s, struct monr *monr, int pad)
+{
+	struct pkg_data *pkgd = NULL;
+	struct monr *pos;
+	struct pmonr *pmonr;
+	int p;
+
+	DBG_PRINTF("\nmonr: %p, parent: %p\n", monr, monr->parent);
+
+	pad++;
+
+	DBG_PRINTF("children: [");
+
+
+	list_for_each_entry(pos, &monr->children, parent_entry)
+		seq_printf(s, "%p, ", pos);
+
+	seq_puts(s, "]\n");
+
+	DBG_PRINTF("mon_cgrp: (%s, %p)",
+		monr->mon_cgrp ? monr->mon_cgrp->css.cgroup->kn->name : "NA",
+		monr->mon_cgrp);
+	DBG_PRINTF("mon_events: %p\n", monr->mon_events);
+
+	DBG_PRINTF("pmonrs:\n");
+	rcu_read_lock();
+	while ((pkgd = cmt_pkgs_data_next_rcu(pkgd))) {
+		pmonr = pkgd_pmonr(pkgd, monr);
+		cmt_dbg_show__pmonr(s, pmonr, pad + 1);
+	}
+	rcu_read_unlock();
+
+	DBG_PRINTF("last_rmid_recoup: %lu, nr_dep_pmonrs: %u, flags: %x\n",
+		atomic64_read(&monr->last_rmid_recoup),
+		atomic_read(&monr->nr_dep_pmonrs), monr->flags);
+	DBG_PRINTF("nr_has_user: %d, nr_nosteal_rmid: %d,",
+		monr->nr_has_user, monr->nr_nosteal_rmid);
+	DBG_PRINTF("nr_nolazy_rmid: %d, uflags: %x\n",
+		monr->nr_nolazy_rmid, monr->uflags);
+	DBG_PRINTF("pkg_uflags: [");
+	for (p = 0; p < topology_max_packages(); p++)
+		seq_printf(s, "%x;", monr->pkg_uflags[p]);
+	seq_puts(s, "]\n");
+}
+
+
+static void cmt_dbg_show__pkgd(struct seq_file *s,
+			       struct pkg_data *pkgd, int pad, bool csd_full)
+{
+	struct pmonr *pmonr;
+	unsigned long flags;
+	int r;
+
+	raw_spin_lock_irqsave(&pkgd->lock, flags);
+
+	DBG_PRINTF("\npkgd: %p, pkgid: %d, max_rmid: %d\n",
+		pkgd, pkgd->pkgid, pkgd->max_rmid);
+	pad++;
+
+	DBG_PRINTF("free_rmids: [%*pbl]\n",
+			CMT_MAX_NR_RMIDS, pkgd->free_rmids);
+	DBG_PRINTF("dirty_rmids: [%*pbl]\n",
+			CMT_MAX_NR_RMIDS, pkgd->dirty_rmids);
+
+	DBG_PRINTF("active_pmonrs:\n");
+	list_for_each_entry(pmonr, &pkgd->active_pmonrs, rot_entry)
+		cmt_dbg_show__pmonr(s, pmonr, pad + 1);
+
+	DBG_PRINTF("dep_idle_pmonrs:\n");
+	list_for_each_entry(pmonr, &pkgd->dep_idle_pmonrs, rot_entry)
+		cmt_dbg_show__pmonr(s, pmonr, pad + 1);
+
+	DBG_PRINTF("dep_dirty_pmonrs:\n");
+	list_for_each_entry(pmonr, &pkgd->dep_dirty_pmonrs, rot_entry)
+		cmt_dbg_show__pmonr(s, pmonr, pad + 1);
+	/*
+	 * only print pmonr pointer since this pmonrs are contained in either
+	 * Dep_Idle or Dep_Dirty pmonrs.
+	 */
+	DBG_PRINTF("dep_pmonrs: [");
+	list_for_each_entry(pmonr, &pkgd->dep_pmonrs, pkgd_deps_entry)
+		seq_printf(s, "%p,", pmonr);
+	seq_puts(s, "]\n");
+
+	DBG_PRINTF("nr_dirty_rmids: %d, nr_dep_pmonrs: %d\n",
+		pkgd->nr_dirty_rmids, pkgd->nr_dep_pmonrs);
+
+	DBG_PRINTF("work_cpu: %d\n", pkgd->work_cpu);
+
+	DBG_PRINTF("ccsds (");
+	if (csd_full)
+		seq_puts(s, "flags, info, func, ");
+	seq_puts(s, "on_read, value, ret, rmid): [");
+
+	pad += 1;
+	for (r = 0; r <= pkgd->max_rmid; r++) {
+		struct cmt_csd *ccsd = &pkgd->ccsds[r];
+
+		if (r % 4 == 0) {
+			seq_puts(s, "\n");
+			DBG_PRINTF("(");
+		} else {
+			seq_puts(s, "(");
+		}
+
+		if (csd_full) {
+			seq_printf(s, "%d,  %p, %p, ", ccsd->csd.flags,
+				   ccsd->csd.info, ccsd->csd.func);
+		}
+		seq_printf(s, "%d, %llu, %d, %d",
+			atomic_read(&ccsd->on_read), ccsd->value,
+			ccsd->ret, ccsd->rmid);
+		seq_puts(s, "),\t");
+	}
+	seq_puts(s, "]");
+	pad -= 1;
+
+	raw_spin_unlock_irqrestore(&pkgd->lock, flags);
+}
+
+static int cmt_dbg_pkgs_show(struct seq_file *s, void *unused)
+{
+	struct pkg_data *pkgd = NULL;
+	int pad = 0;
+
+	mutex_lock(&cmt_mutex);
+
+	while ((pkgd = cmt_pkgs_data_next_rcu(pkgd))) {
+		cmt_dbg_show__pkgd(s, pkgd, pad, false);
+		seq_puts(s, "\n");
+	}
+
+	mutex_unlock(&cmt_mutex);
+
+	return 0;
+}
+
+static int cmt_dbg_hrchy_show(struct seq_file *s, void *unused)
+{
+	struct monr *pos = NULL;
+	int pad = 0;
+
+	mutex_lock(&cmt_mutex);
+	while ((pos = monr_next_descendant_pre(pos, monr_hrchy_root)))
+		cmt_dbg_show__monr(s, pos, pad);
+	mutex_unlock(&cmt_mutex);
+
+	return 0;
+}
+
+/* Must run on a CPU in pkgd's pkg. */
+static int cmt_dbg_rmids__rmids(struct seq_file *s, struct pkg_data *pkgd,
+				unsigned long *rmids, int pad)
+{
+	unsigned long zero_val[CMT_MAX_NR_RMIDS_LONGS];
+	int err, r, nr_printed = 0;
+	u64 val;
+
+	bitmap_copy(zero_val, rmids, CMT_MAX_NR_RMIDS);
+
+	DBG_PRINTF("non-zero value (rmid, scaled llc_occupancy): [");
+	pad++;
+	for_each_set_bit(r, rmids, CMT_MAX_NR_RMIDS) {
+		err = cmt_rmid_read(r, &val);
+		if (!err && !val)
+			continue;
+
+		if (nr_printed % 4 == 0) {
+			seq_puts(s, "\n");
+			DBG_PRINTF("(");
+		} else {
+			seq_puts(s, "(");
+		}
+		nr_printed++;
+
+		if (err) {
+			seq_printf(s, "%d, error: %d),\t", r, err);
+			__clear_bit(r, zero_val);
+			continue;
+		}
+		seq_printf(s, "%d, %llu), ", r, val * cmt_l3_scale);
+		__clear_bit(r, zero_val);
+	}
+	seq_puts(s, "]\n");
+	pad--;
+
+	DBG_PRINTF("zero value: [%*pbl]\n", CMT_MAX_NR_RMIDS, zero_val);
+
+	return 0;
+}
+
+static int __cmt_dbg_rmids__pkgd(struct seq_file *s,
+				struct pkg_data *pkgd, int pad)
+{
+	unsigned long rmids_in_pmonr[CMT_MAX_NR_RMIDS_LONGS];
+	int r;
+
+	memset(rmids_in_pmonr, 0, CMT_MAX_NR_RMIDS_BYTES);
+	bitmap_fill(rmids_in_pmonr, pkgd->max_rmid + 1);
+
+	for_each_set_bit(r, pkgd->free_rmids, CMT_MAX_NR_RMIDS)
+		__clear_bit(r, rmids_in_pmonr);
+
+	for_each_set_bit(r, pkgd->dirty_rmids, CMT_MAX_NR_RMIDS)
+		__clear_bit(r, rmids_in_pmonr);
+
+
+	raw_spin_lock(&pkgd->lock);
+
+	DBG_PRINTF("free_rmids:\n");
+	cmt_dbg_rmids__rmids(s, pkgd, pkgd->free_rmids, pad + 1);
+
+	DBG_PRINTF("dirty_rmids:\n");
+	cmt_dbg_rmids__rmids(s, pkgd, pkgd->dirty_rmids, pad + 1);
+
+	DBG_PRINTF("rmids_in_pmonr:\n");
+	cmt_dbg_rmids__rmids(s, pkgd, rmids_in_pmonr, pad + 1);
+
+	raw_spin_unlock(&pkgd->lock);
+
+	return 0;
+}
+
+struct dbg_smp_data {
+	struct seq_file *s;
+	struct pkg_data *pkgd;
+	int pad;
+};
+
+void cmt_dbg_rmids_pkgd(void *data)
+{
+	struct dbg_smp_data *d;
+
+	d = (struct dbg_smp_data *)data;
+	__cmt_dbg_rmids__pkgd(d->s, d->pkgd, d->pad);
+}
+
+static int cmt_dbg_rmids_show(struct seq_file *s, void *unused)
+{
+	struct dbg_smp_data d;
+	struct pkg_data *pkgd = NULL;
+	int pad = 0, err;
+
+	mutex_lock(&cmt_mutex);
+
+	while ((pkgd = cmt_pkgs_data_next_rcu(pkgd))) {
+		DBG_PRINTF("pkgid: %d\n", pkgd->pkgid);
+		d.s = s;
+		d.pkgd = pkgd;
+		d.pad = pad + 1;
+		err = smp_call_function_single(pkgd->work_cpu,
+					       cmt_dbg_rmids_pkgd, &d, true);
+		seq_puts(s, "\n");
+	}
+
+	mutex_unlock(&cmt_mutex);
+
+	return 0;
+
+}
+
+#define CMT_DBGS_FILE(name__) \
+static int cmt_dbg_ ## name__ ## _open(struct inode *inode, struct file *file)\
+{\
+	return single_open(file, cmt_dbg_ ## name__ ## _show,\
+			   inode->i_private);\
+} \
+static const struct file_operations cmt_dbg_ ## name__ ## _ops = {\
+	.open		= cmt_dbg_ ## name__ ## _open,\
+	.read		= seq_read,\
+	.llseek		= seq_lseek,\
+	.release	= single_release,\
+}
+
+CMT_DBGS_FILE(hrchy);
+CMT_DBGS_FILE(pkgs);
+CMT_DBGS_FILE(rmids);
+
+struct dentry *cmt_dbgfs_root;
+
+static int start_debugfs(void)
+{
+	struct dentry *root, *pkgs, *hrchy, *rmids;
+
+	root = debugfs_create_dir("intel_cmt", NULL);
+	if (IS_ERR(root))
+		return PTR_ERR(root);
+
+	pkgs = debugfs_create_file("pkgs", 0444,
+				   root, NULL, &cmt_dbg_pkgs_ops);
+	if (IS_ERR(pkgs))
+		return PTR_ERR(pkgs);
+
+	hrchy = debugfs_create_file("hrchy", 0444,
+				   root, NULL, &cmt_dbg_hrchy_ops);
+	if (IS_ERR(hrchy))
+		return PTR_ERR(hrchy);
+
+	rmids = debugfs_create_file("rmids", 0444,
+				   root, NULL, &cmt_dbg_rmids_ops);
+	if (IS_ERR(rmids))
+		return PTR_ERR(rmids);
+
+	cmt_dbgfs_root = root;
+
+	return 0;
+}
+
+static void stop_debugfs(void)
+{
+	if (!cmt_dbgfs_root)
+		return;
+	debugfs_remove_recursive(cmt_dbgfs_root);
+	cmt_dbgfs_root = NULL;
+}
+
+#else
+
+static int start_debugfs(void)
+{
+}
+
+static void stop_debugfs(void)
+{
+}
+
+#endif
+
 static struct attribute *intel_cmt_attrs[] = {
 	&dev_attr_max_recycle_threshold.attr,
 	NULL,
@@ -2774,6 +3144,15 @@ static void cmt_stop(void)
 	mutex_unlock(&cmt_mutex);
 }
 
+static void intel_cmt_terminate(void)
+{
+	stop_debugfs();
+	static_branch_dec(&pqr_common_enable_key);
+	perf_pmu_unregister(&intel_cmt_pmu);
+	cmt_stop();
+	cmt_dealloc();
+}
+
 static int __init cmt_alloc(void)
 {
 	pkg_uflags_size = sizeof(*pkg_uflags_zeroes) * topology_max_packages();
@@ -2904,6 +3283,12 @@ static int __init intel_cmt_init(void)
 
 	static_branch_inc(&pqr_common_enable_key);
 
+	err = start_debugfs();
+	if (err) {
+		intel_cmt_terminate();
+		goto err_exit;
+	}
+
 	return err;
 
 err_stop:
-- 
2.8.0.rc3.226.g39d4020