[Intel-gfx] [PATCH v3 05/12] drm/i915/guc: Add a second client, to be used for preemption
Michał Winiarski
michal.winiarski at intel.com
Wed Oct 25 20:00:13 UTC 2017
From: Dave Gordon <david.s.gordon at intel.com>
This second client is created with priority KMD_HIGH, and marked
as preemptive. This will allow us to request preemption using GuC actions.
v2: Extract clients creation into a helper, debugfs fixups. (Michał)
Recreate doorbell on init. (Daniele)
Move clients into an array.
v3: And move clients back from an array, to get rid of the enum (Michał)
Signed-off-by: Dave Gordon <david.s.gordon at intel.com>
Signed-off-by: Michał Winiarski <michal.winiarski at intel.com>
Cc: Chris Wilson <chris at chris-wilson.co.uk>
Cc: Daniele Ceraolo Spurio <daniele.ceraolospurio at intel.com>
Cc: Jeff McGee <jeff.mcgee at intel.com>
Cc: Michal Wajdeczko <michal.wajdeczko at intel.com>
Cc: Oscar Mateo <oscar.mateo at intel.com>
---
drivers/gpu/drm/i915/i915_debugfs.c | 2 +
drivers/gpu/drm/i915/i915_guc_submission.c | 112 ++++++++++++++++++++---------
drivers/gpu/drm/i915/intel_guc.h | 1 +
3 files changed, 82 insertions(+), 33 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_debugfs.c b/drivers/gpu/drm/i915/i915_debugfs.c
index c65e381b85f3..6e178d75bb17 100644
--- a/drivers/gpu/drm/i915/i915_debugfs.c
+++ b/drivers/gpu/drm/i915/i915_debugfs.c
@@ -2484,6 +2484,8 @@ static int i915_guc_info(struct seq_file *m, void *data)
seq_printf(m, "\nGuC execbuf client @ %p:\n", guc->execbuf_client);
i915_guc_client_info(m, dev_priv, guc->execbuf_client);
+ seq_printf(m, "\nGuC preempt client @ %p:\n", guc->preempt_client);
+ i915_guc_client_info(m, dev_priv, guc->preempt_client);
i915_guc_log_info(m, dev_priv);
diff --git a/drivers/gpu/drm/i915/i915_guc_submission.c b/drivers/gpu/drm/i915/i915_guc_submission.c
index d1a5613da24c..1d3123e74bc4 100644
--- a/drivers/gpu/drm/i915/i915_guc_submission.c
+++ b/drivers/gpu/drm/i915/i915_guc_submission.c
@@ -33,10 +33,11 @@
*
* GuC client:
* A i915_guc_client refers to a submission path through GuC. Currently, there
- * is only one of these (the execbuf_client) and this one is charged with all
- * submissions to the GuC. This struct is the owner of a doorbell, a process
- * descriptor and a workqueue (all of them inside a single gem object that
- * contains all required pages for these elements).
+ * are two clients. One of them (the execbuf_client) is charged with all
+ * submissions to the GuC, the other one (preempt_client) is responsible for
+ * preempting the execbuf_client. This struct is the owner of a doorbell, a
+ * process descriptor and a workqueue (all of them inside a single gem object
+ * that contains all required pages for these elements).
*
* GuC stage descriptor:
* During initialization, the driver allocates a static pool of 1024 such
@@ -363,6 +364,8 @@ static void guc_stage_desc_init(struct intel_guc *guc,
memset(desc, 0, sizeof(*desc));
desc->attribute = GUC_STAGE_DESC_ATTR_ACTIVE | GUC_STAGE_DESC_ATTR_KERNEL;
+ if (client->priority <= GUC_CLIENT_PRIORITY_HIGH)
+ desc->attribute |= GUC_STAGE_DESC_ATTR_PREEMPT;
desc->stage_id = client->stage_id;
desc->priority = client->priority;
desc->db_id = client->doorbell_id;
@@ -763,14 +766,18 @@ static int guc_init_doorbell_hw(struct intel_guc *guc)
/* Now for every client (and not only execbuf_client) make sure their
* doorbells are known by the GuC */
- //for (client = client_list; client != NULL; client = client->next)
- {
- ret = __create_doorbell(client);
- if (ret) {
- DRM_ERROR("Couldn't recreate client %u doorbell: %d\n",
- client->stage_id, ret);
- return ret;
- }
+ ret = __create_doorbell(guc->execbuf_client);
+ if (ret) {
+ DRM_ERROR("Couldn't recreate client %u doorbell: %d\n",
+ guc->execbuf_client->stage_id, ret);
+ return ret;
+ }
+
+ ret = __create_doorbell(guc->preempt_client);
+ if (ret) {
+ DRM_ERROR("Couldn't recreate client %u doorbell: %d\n",
+ guc->preempt_client->stage_id, ret);
+ return ret;
}
/* Read back & verify all (used & unused) doorbell registers */
@@ -895,6 +902,47 @@ static void guc_client_free(struct i915_guc_client *client)
kfree(client);
}
+static int guc_clients_create(struct intel_guc *guc)
+{
+ struct drm_i915_private *dev_priv = guc_to_i915(guc);
+ struct i915_guc_client *client;
+
+ client = guc_client_alloc(dev_priv,
+ INTEL_INFO(dev_priv)->ring_mask,
+ GUC_CLIENT_PRIORITY_KMD_NORMAL,
+ dev_priv->kernel_context);
+ if (IS_ERR(client)) {
+ DRM_ERROR("Failed to create GuC client for submission!\n");
+ return PTR_ERR(client);
+ }
+ guc->execbuf_client = client;
+
+ client = guc_client_alloc(dev_priv,
+ INTEL_INFO(dev_priv)->ring_mask,
+ GUC_CLIENT_PRIORITY_KMD_HIGH,
+ dev_priv->preempt_context);
+ if (IS_ERR(client)) {
+ DRM_ERROR("Failed to create GuC client for preemption!\n");
+ guc_client_free(guc->execbuf_client);
+ guc->execbuf_client = NULL;
+ return PTR_ERR(client);
+ }
+ guc->preempt_client = client;
+
+ return 0;
+}
+
+static void guc_clients_destroy(struct intel_guc *guc)
+{
+ struct i915_guc_client *client;
+
+ client = fetch_and_zero(&guc->execbuf_client);
+ guc_client_free(client);
+
+ client = fetch_and_zero(&guc->preempt_client);
+ guc_client_free(client);
+}
+
static void guc_policy_init(struct guc_policy *policy)
{
policy->execution_quantum = POLICY_DEFAULT_EXECUTION_QUANTUM_US;
@@ -1134,7 +1182,6 @@ static void i915_guc_submission_unpark(struct intel_engine_cs *engine)
int i915_guc_submission_enable(struct drm_i915_private *dev_priv)
{
struct intel_guc *guc = &dev_priv->guc;
- struct i915_guc_client *client = guc->execbuf_client;
struct intel_engine_cs *engine;
enum intel_engine_id id;
int err;
@@ -1152,28 +1199,29 @@ int i915_guc_submission_enable(struct drm_i915_private *dev_priv)
sizeof(struct guc_wq_item) *
I915_NUM_ENGINES > GUC_WQ_SIZE);
- if (!client) {
- client = guc_client_alloc(dev_priv,
- INTEL_INFO(dev_priv)->ring_mask,
- GUC_CLIENT_PRIORITY_KMD_NORMAL,
- dev_priv->kernel_context);
- if (IS_ERR(client)) {
- DRM_ERROR("Failed to create GuC client for execbuf!\n");
- return PTR_ERR(client);
- }
-
- guc->execbuf_client = client;
+ /*
+ * We're being called on both module initialization and on reset,
+ * until this flow is changed, we're using regular client presence to
+ * determine which case are we in, and whether we should allocate new
+ * clients or just reset their workqueues.
+ */
+ if (!guc->execbuf_client) {
+ GEM_BUG_ON(guc->preempt_client);
+ err = guc_clients_create(guc);
+ if (err)
+ return err;
+ } else {
+ guc_reset_wq(guc->execbuf_client);
+ guc_reset_wq(guc->preempt_client);
}
err = intel_guc_sample_forcewake(guc);
if (err)
- goto err_execbuf_client;
-
- guc_reset_wq(client);
+ goto err_free_clients;
err = guc_init_doorbell_hw(guc);
if (err)
- goto err_execbuf_client;
+ goto err_free_clients;
/* Take over from manual control of ELSP (execlists) */
guc_interrupts_capture(dev_priv);
@@ -1187,9 +1235,8 @@ int i915_guc_submission_enable(struct drm_i915_private *dev_priv)
return 0;
-err_execbuf_client:
- guc_client_free(guc->execbuf_client);
- guc->execbuf_client = NULL;
+err_free_clients:
+ guc_clients_destroy(guc);
return err;
}
@@ -1204,6 +1251,5 @@ void i915_guc_submission_disable(struct drm_i915_private *dev_priv)
/* Revert back to manual ELSP submission */
intel_engines_reset_default_submission(dev_priv);
- guc_client_free(guc->execbuf_client);
- guc->execbuf_client = NULL;
+ guc_clients_destroy(guc);
}
diff --git a/drivers/gpu/drm/i915/intel_guc.h b/drivers/gpu/drm/i915/intel_guc.h
index aa1583167b0a..6ca55c5bed3c 100644
--- a/drivers/gpu/drm/i915/intel_guc.h
+++ b/drivers/gpu/drm/i915/intel_guc.h
@@ -58,6 +58,7 @@ struct intel_guc {
void *shared_data_vaddr;
struct i915_guc_client *execbuf_client;
+ struct i915_guc_client *preempt_client;
DECLARE_BITMAP(doorbell_bitmap, GUC_NUM_DOORBELLS);
/* Cyclic counter mod pagesize */
--
2.13.6
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