[RFC 3/6] drm: Add fdinfo memory stats

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin at intel.com>

Add support to dump GEM stats to fdinfo.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin at intel.com>
---
 Documentation/gpu/drm-usage-stats.rst | 12 +++++++
 drivers/gpu/drm/drm_file.c            | 52 +++++++++++++++++++++++++++
 include/drm/drm_drv.h                 |  7 ++++
 include/drm/drm_file.h                |  8 +++++
 4 files changed, 79 insertions(+)

diff --git a/Documentation/gpu/drm-usage-stats.rst b/Documentation/gpu/drm-usage-stats.rst
index 2ab32c40e93c..8273a41b2fb0 100644
--- a/Documentation/gpu/drm-usage-stats.rst
+++ b/Documentation/gpu/drm-usage-stats.rst
@@ -21,6 +21,7 @@ File format specification
 
 - File shall contain one key value pair per one line of text.
 - Colon character (`:`) must be used to delimit keys and values.
+- Caret (`^`) is also a reserved character.
 - All keys shall be prefixed with `drm-`.
 - Whitespace between the delimiter and first non-whitespace character shall be
   ignored when parsing.
@@ -105,6 +106,17 @@ object belong to this client, in the respective memory region.
 Default unit shall be bytes with optional unit specifiers of 'KiB' or 'MiB'
 indicating kibi- or mebi-bytes.
 
+- drm-memory-<str>^size:      <uint> [KiB|MiB]
+- drm-memory-<str>^shared:    <uint> [KiB|MiB]
+- drm-memory-<str>^resident:  <uint> [KiB|MiB]
+- drm-memory-<str>^purgeable: <uint> [KiB|MiB]
+- drm-memory-<str>^active:    <uint> [KiB|MiB]
+
+Resident category is identical to the drm-memory-<str> key and two should be
+mutually exclusive.
+
+TODO more description text...
+
 - drm-cycles-<str> <uint>
 
 Engine identifier string must be the same as the one specified in the
diff --git a/drivers/gpu/drm/drm_file.c b/drivers/gpu/drm/drm_file.c
index 37b4f76a5191..e202f79e816d 100644
--- a/drivers/gpu/drm/drm_file.c
+++ b/drivers/gpu/drm/drm_file.c
@@ -42,6 +42,7 @@
 #include <drm/drm_client.h>
 #include <drm/drm_drv.h>
 #include <drm/drm_file.h>
+#include <drm/drm_gem.h>
 #include <drm/drm_print.h>
 
 #include "drm_crtc_internal.h"
@@ -871,6 +872,54 @@ void drm_send_event(struct drm_device *dev, struct drm_pending_event *e)
 }
 EXPORT_SYMBOL(drm_send_event);
 
+static void
+print_stat(struct drm_printer *p, const char *stat, const char *region, u64 sz)
+{
+	const char *units[] = {"", " KiB", " MiB"};
+	unsigned int u;
+
+	if (sz == ~0ull) /* Not supported by the driver. */
+		return;
+
+	for (u = 0; u < ARRAY_SIZE(units) - 1; u++) {
+		if (sz < SZ_1K)
+			break;
+		sz = div_u64(sz, SZ_1K);
+	}
+
+	drm_printf(p, "drm-memory-%s^%s:\t%llu%s\n",
+		   region, stat, sz, units[u]);
+}
+
+static void print_memory_stats(struct drm_printer *p, struct drm_file *file)
+{
+	struct drm_device *dev = file->minor->dev;
+	struct drm_fdinfo_memory_stat *stats;
+	unsigned int num, i;
+	char **regions;
+
+	regions = dev->driver->query_fdinfo_memory_regions(dev, &num);
+
+	stats = kcalloc(num, sizeof(*stats), GFP_KERNEL);
+	if (!stats)
+		return;
+
+	dev->driver->query_fdinfo_memory_stats(file, stats);
+
+	for (i = 0; i < num; i++) {
+		if (!regions[i]) /* Allow sparse name arrays. */
+			continue;
+
+		print_stat(p, "size", regions[i], stats[i].size);
+		print_stat(p, "shared", regions[i], stats[i].shared);
+		print_stat(p, "resident", regions[i], stats[i].resident);
+		print_stat(p, "purgeable", regions[i], stats[i].purgeable);
+		print_stat(p, "active", regions[i], stats[i].active);
+	}
+
+	kfree(stats);
+}
+
 /**
  * drm_show_fdinfo - helper for drm file fops
  * @seq_file: output stream
@@ -900,6 +949,9 @@ void drm_show_fdinfo(struct seq_file *m, struct file *f)
 
 	if (dev->driver->show_fdinfo)
 		dev->driver->show_fdinfo(&p, file);
+
+	if (dev->driver->query_fdinfo_memory_regions)
+		print_memory_stats(&p, file);
 }
 EXPORT_SYMBOL(drm_show_fdinfo);
 
diff --git a/include/drm/drm_drv.h b/include/drm/drm_drv.h
index 89e2706cac56..ccc1cd98d2aa 100644
--- a/include/drm/drm_drv.h
+++ b/include/drm/drm_drv.h
@@ -35,6 +35,7 @@
 #include <drm/drm_device.h>
 
 struct drm_file;
+struct drm_fdinfo_memory_stat;
 struct drm_gem_object;
 struct drm_master;
 struct drm_minor;
@@ -408,6 +409,12 @@ struct drm_driver {
 	 */
 	void (*show_fdinfo)(struct drm_printer *p, struct drm_file *f);
 
+	char ** (*query_fdinfo_memory_regions)(struct drm_device *dev,
+					       unsigned int *num);
+
+	void (*query_fdinfo_memory_stats)(struct drm_file *f,
+					  struct drm_fdinfo_memory_stat *stat);
+
 	/** @major: driver major number */
 	int major;
 	/** @minor: driver minor number */
diff --git a/include/drm/drm_file.h b/include/drm/drm_file.h
index 7d9b3c65cbc1..00d48beeac5c 100644
--- a/include/drm/drm_file.h
+++ b/include/drm/drm_file.h
@@ -375,6 +375,14 @@ struct drm_file {
 #endif
 };
 
+struct drm_fdinfo_memory_stat {
+	u64 size;
+	u64 shared;
+	u64 resident;
+	u64 purgeable;
+	u64 active;
+};
+
 /**
  * drm_is_primary_client - is this an open file of the primary node
  * @file_priv: DRM file
-- 
2.37.2