Testing the stealing of guc ids is hard from user space as we have 64k
guc_ids. Add a selftest, which artificially reduces the number of guc
ids, and forces a steal.
The test creates a spinner which is used to block all subsequent
submissions until it completes. Next, a loop creates a context and a NOP
request each iteration until the guc_ids are exhausted (request creation
returns -EAGAIN). The spinner is ended, unblocking all requests created
in the loop. At this point all guc_ids are exhausted but are available
to steal. Try to create another request which should successfully steal
a guc_id. Wait on last request to complete, idle GPU, verify a guc_id
was stolen via a counter, and exit the test. Test also artificially
reduces the number of guc_ids so the test runs in a timely manner.
v2:
(John Harrison)
- s/stole/stolen
- Fix some wording in test description
- Rework indexing into context array
- Add test description to commit message
- Fix typo in commit message
(Checkpatch)
- s/guc/(guc) in NUMBER_MULTI_LRC_GUC_ID
v3:
(John Harrison)
- Set array value to NULL after extracting error
- Fix a few typos in comments / error messages
- Delete redundant comment in commit message
Signed-off-by: Matthew Brost <matthew.brost@xxxxxxxxx>
---
drivers/gpu/drm/i915/gt/uc/intel_guc.h | 12 ++
.../gpu/drm/i915/gt/uc/intel_guc_submission.c | 16 +-
drivers/gpu/drm/i915/gt/uc/selftest_guc.c | 173 ++++++++++++++++++
3 files changed, 196 insertions(+), 5 deletions(-)
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc.h b/drivers/gpu/drm/i915/gt/uc/intel_guc.h
index 1cb46098030d..f9240d4baa69 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc.h
@@ -94,6 +94,11 @@ struct intel_guc {
* @guc_ids: used to allocate new guc_ids, single-lrc
*/
struct ida guc_ids;
+ /**
+ * @num_guc_ids: Number of guc_ids, selftest feature to be able
+ * to reduce this number while testing.
+ */
+ int num_guc_ids;
/**
* @guc_ids_bitmap: used to allocate new guc_ids, multi-lrc
*/
@@ -202,6 +207,13 @@ struct intel_guc {
*/
struct delayed_work work;
} timestamp;
+
+#ifdef CONFIG_DRM_I915_SELFTEST
+ /**
+ * @number_guc_id_stolen: The number of guc_ids that have been stolen
+ */
+ int number_guc_id_stolen;
+#endif
};
static inline struct intel_guc *log_to_guc(struct intel_guc_log *log)
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
index 96fcf869e3ff..99414b49ca6d 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -145,7 +145,8 @@ guc_create_parallel(struct intel_engine_cs **engines,
* use should be low and 1/16 should be sufficient. Minimum of 32 guc_ids for
* multi-lrc.
*/
-#define NUMBER_MULTI_LRC_GUC_ID (GUC_MAX_LRC_DESCRIPTORS / 16)
+#define NUMBER_MULTI_LRC_GUC_ID(guc) \
+ ((guc)->submission_state.num_guc_ids / 16)
/*
* Below is a set of functions which control the GuC scheduling state which
@@ -1775,7 +1776,7 @@ int intel_guc_submission_init(struct intel_guc *guc)
destroyed_worker_func);
guc->submission_state.guc_ids_bitmap =
- bitmap_zalloc(NUMBER_MULTI_LRC_GUC_ID, GFP_KERNEL);
+ bitmap_zalloc(NUMBER_MULTI_LRC_GUC_ID(guc), GFP_KERNEL);
if (!guc->submission_state.guc_ids_bitmap)
return -ENOMEM;
@@ -1869,13 +1870,13 @@ static int new_guc_id(struct intel_guc *guc, struct intel_context *ce)
if (intel_context_is_parent(ce))
ret = bitmap_find_free_region(guc->submission_state.guc_ids_bitmap,
- NUMBER_MULTI_LRC_GUC_ID,
+ NUMBER_MULTI_LRC_GUC_ID(guc),
order_base_2(ce->parallel.number_children
+ 1));
else
ret = ida_simple_get(&guc->submission_state.guc_ids,
- NUMBER_MULTI_LRC_GUC_ID,
- GUC_MAX_LRC_DESCRIPTORS,
+ NUMBER_MULTI_LRC_GUC_ID(guc),
+ guc->submission_state.num_guc_ids,
GFP_KERNEL | __GFP_RETRY_MAYFAIL |
__GFP_NOWARN);
if (unlikely(ret < 0))
@@ -1941,6 +1942,10 @@ static int steal_guc_id(struct intel_guc *guc, struct intel_context *ce)
set_context_guc_id_invalid(cn);
+#ifdef CONFIG_DRM_I915_SELFTEST
+ guc->number_guc_id_stolen++;
+#endif
+
return 0;
} else {
return -EAGAIN;
@@ -3779,6 +3784,7 @@ static bool __guc_submission_selected(struct intel_guc *guc)
void intel_guc_submission_init_early(struct intel_guc *guc)
{
+ guc->submission_state.num_guc_ids = GUC_MAX_LRC_DESCRIPTORS;
guc->submission_supported = __guc_submission_supported(guc);
guc->submission_selected = __guc_submission_selected(guc);
}
diff --git a/drivers/gpu/drm/i915/gt/uc/selftest_guc.c b/drivers/gpu/drm/i915/gt/uc/selftest_guc.c
index fb0e4a7bd8ca..2ae414446112 100644
--- a/drivers/gpu/drm/i915/gt/uc/selftest_guc.c
+++ b/drivers/gpu/drm/i915/gt/uc/selftest_guc.c
@@ -3,8 +3,21 @@
* Copyright �� 2021 Intel Corporation
*/
+#include "selftests/igt_spinner.h"
#include "selftests/intel_scheduler_helpers.h"
+static int request_add_spin(struct i915_request *rq, struct igt_spinner *spin)
+{
+ int err = 0;
+
+ i915_request_get(rq);
+ i915_request_add(rq);
+ if (spin && !igt_wait_for_spinner(spin, rq))
+ err = -ETIMEDOUT;
+
+ return err;
+}
+
static struct i915_request *nop_user_request(struct intel_context *ce,
struct i915_request *from)
{
@@ -110,10 +123,170 @@ static int intel_guc_scrub_ctbs(void *arg)
return ret;
}
+/*
+ * intel_guc_steal_guc_ids - Test to exhaust all guc_ids and then steal one
+ *
+ * This test creates a spinner which is used to block all subsequent submissions
+ * until it completes. Next, a loop creates a context and a NOP request each
+ * iteration until the guc_ids are exhausted (request creation returns -EAGAIN).
+ * The spinner is ended, unblocking all requests created in the loop. At this
+ * point all guc_ids are exhausted but are available to steal. Try to create
+ * another request which should successfully steal a guc_id. Wait on last
+ * request to complete, idle GPU, verify a guc_id was stolen via a counter, and
+ * exit the test. Test also artificially reduces the number of guc_ids so the
+ * test runs in a timely manner.
+ */
+static int intel_guc_steal_guc_ids(void *arg)
+{
+ struct intel_gt *gt = arg;
+ struct intel_guc *guc = >->uc.guc;
+ int ret, sv, context_index = 0;
+ intel_wakeref_t wakeref;
+ struct intel_engine_cs *engine;
+ struct intel_context **ce;
+ struct igt_spinner spin;
+ struct i915_request *spin_rq = NULL, *rq, *last = NULL;
+ int number_guc_id_stolen = guc->number_guc_id_stolen;
+
+ ce = kzalloc(sizeof(*ce) * GUC_MAX_LRC_DESCRIPTORS, GFP_KERNEL);
+ if (!ce) {
+ pr_err("Context array allocation failed\n");
+ return -ENOMEM;
+ }
+
+ wakeref = intel_runtime_pm_get(gt->uncore->rpm);
+ engine = intel_selftest_find_any_engine(gt);
+ sv = guc->submission_state.num_guc_ids;
+ guc->submission_state.num_guc_ids = 4096;
+
+ /* Create spinner to block requests in below loop */
+ ce[context_index] = intel_context_create(engine);
+ if (IS_ERR(ce[context_index])) {
+ ret = PTR_ERR(ce[context_index]);
+ ce[context_index] = NULL;
+ pr_err("Failed to create context: %d\n", ret);
+ goto err_wakeref;
+ }
+ ret = igt_spinner_init(&spin, engine->gt);
+ if (ret) {
+ pr_err("Failed to create spinner: %d\n", ret);
+ goto err_contexts;
+ }
+ spin_rq = igt_spinner_create_request(&spin, ce[context_index],
+ MI_ARB_CHECK);
+ if (IS_ERR(spin_rq)) {
+ ret = PTR_ERR(spin_rq);
+ pr_err("Failed to create spinner request: %d\n", ret);
+ goto err_contexts;
+ }
+ ret = request_add_spin(spin_rq, &spin);
+ if (ret) {
+ pr_err("Failed to add Spinner request: %d\n", ret);
+ goto err_spin_rq;
+ }
+
+ /* Use all guc_ids */
+ while (ret != -EAGAIN) {
+ ce[++context_index] = intel_context_create(engine);
+ if (IS_ERR(ce[context_index])) {
+ ret = PTR_ERR(ce[context_index--]);
+ ce[context_index] = NULL;
+ pr_err("Failed to create context: %d\n", ret);
+ goto err_spin_rq;
+ }
+
+ rq = nop_user_request(ce[context_index], spin_rq);
+ if (IS_ERR(rq)) {
+ ret = PTR_ERR(rq);
+ rq = NULL;
+ if (ret != -EAGAIN) {
+ pr_err("Failed to create request, %d: %d\n",
+ context_index, ret);
+ goto err_spin_rq;
+ }
+ } else {
+ if (last)
+ i915_request_put(last);
+ last = rq;
+ }
+ }
+
+ /* Release blocked requests */
+ igt_spinner_end(&spin);
+ ret = intel_selftest_wait_for_rq(spin_rq);
+ if (ret) {
+ pr_err("Spin request failed to complete: %d\n", ret);
+ i915_request_put(last);
+ goto err_spin_rq;
+ }
+ i915_request_put(spin_rq);
+ igt_spinner_fini(&spin);
+ spin_rq = NULL;
+
+ /* Wait for last request */
+ ret = i915_request_wait(last, 0, HZ * 30);
+ i915_request_put(last);
+ if (ret < 0) {
+ pr_err("Last request failed to complete: %d\n", ret);
+ goto err_spin_rq;
+ }
+
+ /* Try to steal guc_id */
+ rq = nop_user_request(ce[context_index], NULL);
+ if (IS_ERR(rq)) {
+ ret = PTR_ERR(rq);
+ pr_err("Failed to steal guc_id, %d: %d\n", context_index, ret);
+ goto err_spin_rq;
+ }
+
+ /* Wait for request with stolen guc_id */
+ ret = i915_request_wait(rq, 0, HZ);
+ i915_request_put(rq);
+ if (ret < 0) {
+ pr_err("Request with stolen guc_id failed to complete: %d\n",
+ ret);
+ goto err_spin_rq;
+ }
+
+ /* Wait for idle */
+ ret = intel_gt_wait_for_idle(gt, HZ * 30);
+ if (ret < 0) {
+ pr_err("GT failed to idle: %d\n", ret);
+ goto err_spin_rq;
+ }
+
+ /* Verify a guc_id was stolen */
+ if (guc->number_guc_id_stolen == number_guc_id_stolen) {
+ pr_err("No guc_id was stolen");
+ ret = -EINVAL;
+ } else {
+ ret = 0;
+ }
+
+err_spin_rq:
+ if (spin_rq) {
+ igt_spinner_end(&spin);
+ intel_selftest_wait_for_rq(spin_rq);
+ i915_request_put(spin_rq);
+ igt_spinner_fini(&spin);
+ intel_gt_wait_for_idle(gt, HZ * 30);
+ }
+err_contexts:
+ for (; context_index >= 0 && ce[context_index]; --context_index)
+ intel_context_put(ce[context_index]);
+err_wakeref:
+ intel_runtime_pm_put(gt->uncore->rpm, wakeref);
+ kfree(ce);
+ guc->submission_state.num_guc_ids = sv;
+
+ return ret;
+}
+
int intel_guc_live_selftests(struct drm_i915_private *i915)
{
static const struct i915_subtest tests[] = {
SUBTEST(intel_guc_scrub_ctbs),
+ SUBTEST(intel_guc_steal_guc_ids),
};
struct intel_gt *gt = &i915->gt;
--
2.33.1
