[PATCH 1/2] drm/xe/gt: Add APIs for printing stats over debugfs

[Nirmoy Das]

Add skeleton APIs for recording and printing various stats over
debugfs. This currently only added counter types stats which is backed
by atomic_t and wrapped with CONFIG_DRM_XE_STATS so this can be disabled
on production system.

Cc: Matthew Brost <matthew.brost at intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Signed-off-by: Nirmoy Das <nirmoy.das at intel.com>
---
 drivers/gpu/drm/xe/Kconfig.debug   | 11 +++++++++++
 drivers/gpu/drm/xe/Makefile        |  2 ++
 drivers/gpu/drm/xe/xe_gt_debugfs.c |  4 ++++
 drivers/gpu/drm/xe/xe_gt_stats.c   | 30 +++++++++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_gt_stats.h   | 31 ++++++++++++++++++++++++++++++
 drivers/gpu/drm/xe/xe_gt_types.h   |  7 +++++++
 6 files changed, 85 insertions(+)
 create mode 100644 drivers/gpu/drm/xe/xe_gt_stats.c
 create mode 100644 drivers/gpu/drm/xe/xe_gt_stats.h

diff --git a/drivers/gpu/drm/xe/Kconfig.debug b/drivers/gpu/drm/xe/Kconfig.debug
index bc177368af6c..4db6d707c1af 100644
--- a/drivers/gpu/drm/xe/Kconfig.debug
+++ b/drivers/gpu/drm/xe/Kconfig.debug
@@ -94,3 +94,14 @@ config DRM_XE_USERPTR_INVAL_INJECT
 
 	 Recomended for driver developers only.
 	 If in doubt, say "N".
+
+config DRM_XE_STATS
+	bool "Enable XE statistics"
+	default n
+	help
+	  Choose this option to enable support for collecting and
+	  displaying XE statistics as debugfs.
+
+	  Recommended for driver developers only.
+
+	  If in doubt, say "N".
diff --git a/drivers/gpu/drm/xe/Makefile b/drivers/gpu/drm/xe/Makefile
index 1ff9602a52f6..b0bbb248f644 100644
--- a/drivers/gpu/drm/xe/Makefile
+++ b/drivers/gpu/drm/xe/Makefile
@@ -143,6 +143,8 @@ xe-$(CONFIG_PCI_IOV) += \
 	xe_pci_sriov.o \
 	xe_sriov_pf.o
 
+xe-$(CONFIG_DRM_XE_STATS) += xe_gt_stats.o
+
 # include helpers for tests even when XE is built-in
 ifdef CONFIG_DRM_XE_KUNIT_TEST
 xe-y += tests/xe_kunit_helpers.o
diff --git a/drivers/gpu/drm/xe/xe_gt_debugfs.c b/drivers/gpu/drm/xe/xe_gt_debugfs.c
index 5e7fd937917a..3765c04919dc 100644
--- a/drivers/gpu/drm/xe/xe_gt_debugfs.c
+++ b/drivers/gpu/drm/xe/xe_gt_debugfs.c
@@ -17,6 +17,7 @@
 #include "xe_gt_mcr.h"
 #include "xe_gt_sriov_pf_debugfs.h"
 #include "xe_gt_sriov_vf_debugfs.h"
+#include "xe_gt_stats.h"
 #include "xe_gt_topology.h"
 #include "xe_hw_engine.h"
 #include "xe_lrc.h"
@@ -286,6 +287,9 @@ static const struct drm_info_list debugfs_list[] = {
 	{"default_lrc_bcs", .show = xe_gt_debugfs_simple_show, .data = bcs_default_lrc},
 	{"default_lrc_vcs", .show = xe_gt_debugfs_simple_show, .data = vcs_default_lrc},
 	{"default_lrc_vecs", .show = xe_gt_debugfs_simple_show, .data = vecs_default_lrc},
+#if IS_ENABLED(CONFIG_DRM_XE_STATS)
+	{"stats", .show = xe_gt_debugfs_simple_show, .data = xe_gt_stats_print_info},
+#endif
 };
 
 void xe_gt_debugfs_register(struct xe_gt *gt)
diff --git a/drivers/gpu/drm/xe/xe_gt_stats.c b/drivers/gpu/drm/xe/xe_gt_stats.c
new file mode 100644
index 000000000000..cc69d748e8f6
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_gt_stats.c
@@ -0,0 +1,30 @@
+// SPDX-License-Identifier: MIT
+/*
+ * Copyright © 2024 Intel Corporation
+ */
+
+#include <linux/atomic.h>
+
+#include "xe_gt.h"
+#include "xe_gt_stats.h"
+
+#ifdef CONFIG_DRM_XE_STATS
+void xe_gt_stats_incr(struct xe_gt *gt, enum xe_gt_counter_stats id, int incr)
+{
+	atomic_add(incr, &gt->stats.counters[id]);
+}
+
+static const char *const stat_description[] = {
+};
+
+int xe_gt_stats_print_info(struct xe_gt *gt, struct drm_printer *p)
+{
+	enum xe_gt_counter_stats id;
+
+	for (id = 0; id < XE_GT_COUNTER_STATS_NUM; ++id)
+		drm_printf(p, "%s: %d\n", stat_description[id],
+			   atomic_read(&gt->stats.counters[id]));
+
+	return 0;
+}
+#endif
diff --git a/drivers/gpu/drm/xe/xe_gt_stats.h b/drivers/gpu/drm/xe/xe_gt_stats.h
new file mode 100644
index 000000000000..e83155ab1fdb
--- /dev/null
+++ b/drivers/gpu/drm/xe/xe_gt_stats.h
@@ -0,0 +1,31 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2024 Intel Corporation
+ */
+
+#ifndef _XE_GT_STATS_H_
+#define _XE_GT_STATS_H_
+
+#include <drm/drm_print.h>
+
+struct xe_gt;
+//struct drm_printer;
+
+enum xe_gt_counter_stats {
+	XE_GT_COUNTER_STATS_NUM,
+};
+
+#ifdef CONFIG_DRM_XE_STATS
+int xe_gt_stats_print_info(struct xe_gt *gt, struct drm_printer *p);
+void xe_gt_stats_incr(struct xe_gt *gt, enum xe_gt_counter_stats stat, int incr);
+#else
+int xe_gt_stats_print_info(struct xe_gt *gt, struct drm_printer *p)
+{
+}
+
+void xe_gt_stats_incr(struct xe_gt *gt, enum xe_gt_counter_stats stat, int incr)
+{
+}
+
+#endif /* CONFIG_DRM_XE_STATS */
+#endif /* _XE_GT_STATS_H_ */
diff --git a/drivers/gpu/drm/xe/xe_gt_types.h b/drivers/gpu/drm/xe/xe_gt_types.h
index 631928258d71..0ded57b56628 100644
--- a/drivers/gpu/drm/xe/xe_gt_types.h
+++ b/drivers/gpu/drm/xe/xe_gt_types.h
@@ -10,6 +10,7 @@
 #include "xe_gt_idle_types.h"
 #include "xe_gt_sriov_pf_types.h"
 #include "xe_gt_sriov_vf_types.h"
+#include "xe_gt_stats.h"
 #include "xe_hw_engine_types.h"
 #include "xe_hw_fence_types.h"
 #include "xe_oa.h"
@@ -133,6 +134,12 @@ struct xe_gt {
 		u8 has_indirect_ring_state:1;
 	} info;
 
+#if IS_ENABLED(CONFIG_DRM_XE_STATS)
+	struct {
+		atomic_t counters[XE_GT_COUNTER_STATS_NUM];
+	} stats;
+#endif
+
 	/**
 	 * @mmio: mmio info for GT.  All GTs within a tile share the same
 	 * register space, but have their own copy of GSI registers at a
-- 
2.42.0