[RFC 03/12] cgroup: Add the DRM cgroup controller

Tvrtko Ursulin
2023-01-12T16:56:00Z

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

Skeleton controller without any functionality.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
---
include/linux/cgroup_drm.h | 9 ++++++
include/linux/cgroup_subsys.h | 4 +++
init/Kconfig | 7 +++++
kernel/cgroup/Makefile | 1 +
kernel/cgroup/drm.c | 59 +++++++++++++++++++++++++++++++++++
5 files changed, 80 insertions(+)
create mode 100644 include/linux/cgroup_drm.h
create mode 100644 kernel/cgroup/drm.c

diff --git a/include/linux/cgroup_drm.h b/include/linux/cgroup_drm.h
new file mode 100644
index 000000000000..bf8abc6b8ebf
--- /dev/null
+++ b/include/linux/cgroup_drm.h
@@ -0,0 +1,9 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#ifndef _CGROUP_DRM_H
+#define _CGROUP_DRM_H
+
+#endif /* _CGROUP_DRM_H */
diff --git a/include/linux/cgroup_subsys.h b/include/linux/cgroup_subsys.h
index 445235487230..49460494a010 100644
--- a/include/linux/cgroup_subsys.h
+++ b/include/linux/cgroup_subsys.h
@@ -65,6 +65,10 @@ SUBSYS(rdma)
SUBSYS(misc)
#endif

+#if IS_ENABLED(CONFIG_CGROUP_DRM)
+SUBSYS(drm)
+#endif
+
/*
* The following subsystems are not supported on the default hierarchy.
*/
diff --git a/init/Kconfig b/init/Kconfig
index 7e5c3ddc341d..c5ace0d57007 100644
--- a/init/Kconfig
+++ b/init/Kconfig
@@ -1089,6 +1089,13 @@ config CGROUP_RDMA
Attaching processes with active RDMA resources to the cgroup
hierarchy is allowed even if can cross the hierarchy's limit.

+config CGROUP_DRM
+ bool "DRM controller"
+ help
+ Provides the DRM subsystem controller.
+
+ ...
+
config CGROUP_FREEZER
bool "Freezer controller"
help
diff --git a/kernel/cgroup/Makefile b/kernel/cgroup/Makefile
index 12f8457ad1f9..849bd2917477 100644
--- a/kernel/cgroup/Makefile
+++ b/kernel/cgroup/Makefile
@@ -6,4 +6,5 @@ obj-$(CONFIG_CGROUP_PIDS) += pids.o
obj-$(CONFIG_CGROUP_RDMA) += rdma.o
obj-$(CONFIG_CPUSETS) += cpuset.o
obj-$(CONFIG_CGROUP_MISC) += misc.o
+obj-$(CONFIG_CGROUP_DRM) += drm.o
obj-$(CONFIG_CGROUP_DEBUG) += debug.o
diff --git a/kernel/cgroup/drm.c b/kernel/cgroup/drm.c
new file mode 100644
index 000000000000..48a8d646a094
--- /dev/null
+++ b/kernel/cgroup/drm.c
@@ -0,0 +1,59 @@
+/* SPDX-License-Identifier: MIT */
+/*
+ * Copyright © 2022 Intel Corporation
+ */
+
+#include <linux/slab.h>
+#include <linux/cgroup.h>
+#include <linux/cgroup_drm.h>
+#include <linux/sched.h>
+
+struct drm_cgroup_state {
+ struct cgroup_subsys_state css;
+};
+
+struct drm_root_cgroup_state {
+ struct drm_cgroup_state drmcs;
+};
+
+static inline struct drm_cgroup_state *
+css_to_drmcs(struct cgroup_subsys_state *css)
+{
+ return container_of(css, struct drm_cgroup_state, css);
+}
+
+static struct drm_root_cgroup_state root_drmcs;
+
+static void drmcs_free(struct cgroup_subsys_state *css)
+{
+ if (css != &root_drmcs.drmcs.css)
+ kfree(css_to_drmcs(css));
+}
+
+static struct cgroup_subsys_state *
+drmcs_alloc(struct cgroup_subsys_state *parent_css)
+{
+ struct drm_cgroup_state *drmcs;
+
+ if (!parent_css) {
+ drmcs = &root_drmcs.drmcs;
+ } else {
+ drmcs = kzalloc(sizeof(*drmcs), GFP_KERNEL);
+ if (!drmcs)
+ return ERR_PTR(-ENOMEM);
+ }
+
+ return &drmcs->css;
+}
+
+struct cftype files[] = {
+ { } /* Zero entry terminates. */
+};
+
+struct cgroup_subsys drm_cgrp_subsys = {
+ .css_alloc = drmcs_alloc,
+ .css_free = drmcs_free,
+ .early_init = false,
+ .legacy_cftypes = files,
+ .dfl_cftypes = files,
+};
--
2.34.1