[RFC 07/17] drm/i915: i915 priority

[Tvrtko Ursulin]

From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>

Register i915 as supporting the drm cgroup controller priority management
and wire it up at execbuf time.

GEM context configured priority then works as a relative value on top of
the base level obtained from the drm cgroup controller.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxx>
---
 .../gpu/drm/i915/gem/i915_gem_execbuffer.c    | 27 ++++++++++++++++++-
 drivers/gpu/drm/i915/i915_driver.c            | 10 +++++++
 drivers/gpu/drm/i915/i915_drm_client.c        | 16 +++++++++++
 drivers/gpu/drm/i915/i915_drm_client.h        |  4 +++
 4 files changed, 56 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
index 1160723c9d2d..391c5b5c80be 100644
--- a/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_execbuffer.c
@@ -4,8 +4,10 @@
  * Copyright © 2008,2010 Intel Corporation
  */
 
+#include <linux/cgroup_drm.h>
 #include <linux/dma-resv.h>
 #include <linux/highmem.h>
+#include <linux/minmax.h>
 #include <linux/sync_file.h>
 #include <linux/uaccess.h>
 
@@ -3015,6 +3017,29 @@ static void retire_requests(struct intel_timeline *tl, struct i915_request *end)
 			break;
 }
 
+#ifdef CONFIG_CGROUP_DRM
+static void copy_priority(struct i915_sched_attr *attr,
+			  const struct i915_execbuffer *eb)
+{
+	const int scale = DIV_ROUND_CLOSEST(DRM_CGROUP_PRIORITY_MAX,
+					    I915_CONTEXT_MAX_USER_PRIORITY);
+	int prio;
+
+	*attr = eb->gem_context->sched;
+	prio = attr->priority * scale + eb->file->drm_cgroup_priority;
+	prio = DIV_ROUND_UP(prio, scale);
+	attr->priority = clamp(prio,
+			       I915_CONTEXT_MIN_USER_PRIORITY,
+			       I915_CONTEXT_MAX_USER_PRIORITY);
+}
+#else
+static void copy_priority(struct i915_sched_attr *attr,
+			  const struct i915_execbuffer *eb)
+{
+	*attr = eb->gem_context->sched;
+}
+#endif
+
 static int eb_request_add(struct i915_execbuffer *eb, struct i915_request *rq,
 			  int err, bool last_parallel)
 {
@@ -3031,7 +3056,7 @@ static int eb_request_add(struct i915_execbuffer *eb, struct i915_request *rq,
 
 	/* Check that the context wasn't destroyed before submission */
 	if (likely(!intel_context_is_closed(eb->context))) {
-		attr = eb->gem_context->sched;
+		copy_priority(&attr, eb);
 	} else {
 		/* Serialise with context_close via the add_to_timeline */
 		i915_request_set_error_once(rq, -ENOENT);
diff --git a/drivers/gpu/drm/i915/i915_driver.c b/drivers/gpu/drm/i915/i915_driver.c
index ffff49868dc5..7912782b87cc 100644
--- a/drivers/gpu/drm/i915/i915_driver.c
+++ b/drivers/gpu/drm/i915/i915_driver.c
@@ -1893,6 +1893,12 @@ static const struct drm_ioctl_desc i915_ioctls[] = {
 	DRM_IOCTL_DEF_DRV(I915_GEM_VM_DESTROY, i915_gem_vm_destroy_ioctl, DRM_RENDER_ALLOW),
 };
 
+#ifdef CONFIG_CGROUP_DRM
+static const struct drm_cgroup_ops i915_drm_cgroup_ops = {
+	.priority_levels = i915_drm_priority_levels,
+};
+#endif
+
 /*
  * Interface history:
  *
@@ -1921,6 +1927,10 @@ static const struct drm_driver i915_drm_driver = {
 	.lastclose = i915_driver_lastclose,
 	.postclose = i915_driver_postclose,
 
+#ifdef CONFIG_CGROUP_DRM
+	.cg_ops = &i915_drm_cgroup_ops,
+#endif
+
 	.prime_handle_to_fd = drm_gem_prime_handle_to_fd,
 	.prime_fd_to_handle = drm_gem_prime_fd_to_handle,
 	.gem_prime_import = i915_gem_prime_import,
diff --git a/drivers/gpu/drm/i915/i915_drm_client.c b/drivers/gpu/drm/i915/i915_drm_client.c
index b09d1d386574..61a3cdaa7b16 100644
--- a/drivers/gpu/drm/i915/i915_drm_client.c
+++ b/drivers/gpu/drm/i915/i915_drm_client.c
@@ -75,6 +75,22 @@ void i915_drm_clients_fini(struct i915_drm_clients *clients)
 	xa_destroy(&clients->xarray);
 }
 
+#ifdef CONFIG_CGROUP_DRM
+unsigned int i915_drm_priority_levels(struct drm_file *file)
+{
+	struct drm_i915_file_private *fpriv = file->driver_priv;
+	struct i915_drm_client *client = fpriv->client;
+	struct drm_i915_private *i915 = client->clients->i915;
+
+	if (GRAPHICS_VER(i915) < 8)
+		return 0;
+	else if (intel_uc_uses_guc_submission(&to_gt(i915)->uc))
+		return 3;
+	else
+		return 2047;
+}
+#endif
+
 #ifdef CONFIG_PROC_FS
 static const char * const uabi_class_names[] = {
 	[I915_ENGINE_CLASS_RENDER] = "render",
diff --git a/drivers/gpu/drm/i915/i915_drm_client.h b/drivers/gpu/drm/i915/i915_drm_client.h
index 69496af996d9..bd5925241007 100644
--- a/drivers/gpu/drm/i915/i915_drm_client.h
+++ b/drivers/gpu/drm/i915/i915_drm_client.h
@@ -15,6 +15,8 @@
 
 #define I915_LAST_UABI_ENGINE_CLASS I915_ENGINE_CLASS_COMPUTE
 
+struct drm_file;
+
 struct drm_i915_private;
 
 struct i915_drm_clients {
@@ -65,4 +67,6 @@ void i915_drm_client_fdinfo(struct seq_file *m, struct file *f);
 
 void i915_drm_clients_fini(struct i915_drm_clients *clients);
 
+unsigned int i915_drm_priority_levels(struct drm_file *file);
+
 #endif /* !__I915_DRM_CLIENT_H__ */
-- 
2.34.1