On Thu, Sep 22, 2022 at 01:12:09PM -0700, John.C.Harrison@xxxxxxxxx wrote:
From: John Harrison <John.C.Harrison@xxxxxxxxx>
DG2 has issues. To work around one of these the GuC must schedule
apps in an exclusive manner across both RCS and CCS. That is, if a
context from app X is running on RCS then all CCS engines must sit
idle even if there are contexts from apps Y, Z, ... waiting to run. A
certain OS favours RCS to the total starvation of CCS. Linux does not.
Hence the GuC now has a scheduling policy setting to control this
abitration.
Signed-off-by: John Harrison <John.C.Harrison@xxxxxxxxx>
lgtm,
Reviewed-by: Umesh Nerlige Ramappa <umesh.nerlige.ramappa@xxxxxxxxx>
Regards,
Umesh
---
.../gpu/drm/i915/gt/uc/abi/guc_actions_abi.h | 1 +
drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h | 9 +-
drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h | 22 +++++
.../gpu/drm/i915/gt/uc/intel_guc_submission.c | 93 +++++++++++++++++++
4 files changed, 124 insertions(+), 1 deletion(-)
diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
index 29ef8afc8c2e4..f359bef046e0b 100644
--- a/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
+++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_actions_abi.h
@@ -117,6 +117,7 @@ enum intel_guc_action {
INTEL_GUC_ACTION_ENTER_S_STATE = 0x501,
INTEL_GUC_ACTION_EXIT_S_STATE = 0x502,
INTEL_GUC_ACTION_GLOBAL_SCHED_POLICY_CHANGE = 0x506,
+ INTEL_GUC_ACTION_UPDATE_SCHEDULING_POLICIES_KLV = 0x509,
INTEL_GUC_ACTION_SCHED_CONTEXT = 0x1000,
INTEL_GUC_ACTION_SCHED_CONTEXT_MODE_SET = 0x1001,
INTEL_GUC_ACTION_SCHED_CONTEXT_MODE_DONE = 0x1002,
diff --git a/drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h b/drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h
index 4a59478c3b5c4..58012edd4eb0e 100644
--- a/drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h
+++ b/drivers/gpu/drm/i915/gt/uc/abi/guc_klvs_abi.h
@@ -81,10 +81,17 @@
#define GUC_KLV_SELF_CFG_G2H_CTB_SIZE_KEY 0x0907
#define GUC_KLV_SELF_CFG_G2H_CTB_SIZE_LEN 1u
+/*
+ * Global scheduling policy update keys.
+ */
+enum {
+ GUC_SCHEDULING_POLICIES_KLV_ID_RENDER_COMPUTE_YIELD = 0x1001,
+};
+
/*
* Per context scheduling policy update keys.
*/
-enum {
+enum {
GUC_CONTEXT_POLICIES_KLV_ID_EXECUTION_QUANTUM = 0x2001,
GUC_CONTEXT_POLICIES_KLV_ID_PREEMPTION_TIMEOUT = 0x2002,
GUC_CONTEXT_POLICIES_KLV_ID_SCHEDULING_PRIORITY = 0x2003,
diff --git a/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h b/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h
index 323b055e5db97..e7a7fb450f442 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_fwif.h
@@ -290,6 +290,25 @@ struct guc_update_context_policy {
struct guc_klv_generic_dw_t klv[GUC_CONTEXT_POLICIES_KLV_NUM_IDS];
} __packed;
+/* Format of the UPDATE_SCHEDULING_POLICIES H2G data packet */
+struct guc_update_scheduling_policy_header {
+ u32 action;
+} __packed;
+
+/*
+ * Can't dynmically allocate memory for the scheduling policy KLV because
+ * it will be sent from within the reset path. Need a fixed size lump on
+ * the stack instead :(.
+ *
+ * Currently, there is only one KLV defined, which has 1 word of KL + 2 words of V.
+ */
+#define MAX_SCHEDULING_POLICY_SIZE 3
+
+struct guc_update_scheduling_policy {
+ struct guc_update_scheduling_policy_header header;
+ u32 data[MAX_SCHEDULING_POLICY_SIZE];
+} __packed;
+
#define GUC_POWER_UNSPECIFIED 0
#define GUC_POWER_D0 1
#define GUC_POWER_D1 2
@@ -298,6 +317,9 @@ struct guc_update_context_policy {
/* Scheduling policy settings */
+#define GLOBAL_SCHEDULE_POLICY_RC_YIELD_DURATION 100 /* in ms */
+#define GLOBAL_SCHEDULE_POLICY_RC_YIELD_RATIO 50 /* in percent */
+
#define GLOBAL_POLICY_MAX_NUM_WI 15
/* Don't reset an engine upon preemption failure */
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 22ba66e48a9b0..f09f530198f4d 100644
--- a/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
+++ b/drivers/gpu/drm/i915/gt/uc/intel_guc_submission.c
@@ -4177,6 +4177,98 @@ int intel_guc_submission_setup(struct intel_engine_cs *engine)
return 0;
}
+struct scheduling_policy {
+ /* internal data */
+ u32 max_words, num_words;
+ u32 count;
+ /* API data */
+ struct guc_update_scheduling_policy h2g;
+};
+
+static u32 __guc_scheduling_policy_action_size(struct scheduling_policy *policy)
+{
+ u32 *start = (void *)&policy->h2g;
+ u32 *end = policy->h2g.data + policy->num_words;
+ size_t delta = end - start;
+
+ return delta;
+}
+
+static struct scheduling_policy *__guc_scheduling_policy_start_klv(struct scheduling_policy *policy)
+{
+ policy->h2g.header.action = INTEL_GUC_ACTION_UPDATE_SCHEDULING_POLICIES_KLV;
+ policy->max_words = ARRAY_SIZE(policy->h2g.data);
+ policy->num_words = 0;
+ policy->count = 0;
+
+ return policy;
+}
+
+static void __guc_scheduling_policy_add_klv(struct scheduling_policy *policy,
+ u32 action, u32 *data, u32 len)
+{
+ u32 *klv_ptr = policy->h2g.data + policy->num_words;
+
+ GEM_BUG_ON((policy->num_words + 1 + len) > policy->max_words);
+ *(klv_ptr++) = FIELD_PREP(GUC_KLV_0_KEY, action) |
+ FIELD_PREP(GUC_KLV_0_LEN, len);
+ memcpy(klv_ptr, data, sizeof(u32) * len);
+ policy->num_words += 1 + len;
+ policy->count++;
+}
+
+static int __guc_action_set_scheduling_policies(struct intel_guc *guc,
+ struct scheduling_policy *policy)
+{
+ int ret;
+
+ ret = intel_guc_send(guc, (u32 *)&policy->h2g,
+ __guc_scheduling_policy_action_size(policy));
+ if (ret < 0)
+ return ret;
+
+ if (ret != policy->count) {
+ drm_warn(&guc_to_gt(guc)->i915->drm, "GuC global scheduler policy processed %d of %d KLVs!",
+ ret, policy->count);
+ if (ret > policy->count)
+ return -EPROTO;
+ }
+
+ return 0;
+}
+
+static int guc_init_global_schedule_policy(struct intel_guc *guc)
+{
+ struct scheduling_policy policy;
+ struct intel_gt *gt = guc_to_gt(guc);
+ intel_wakeref_t wakeref;
+ int ret = 0;
+
+ if (GET_UC_VER(guc) < MAKE_UC_VER(70, 3, 0))
+ return 0;
+
+ __guc_scheduling_policy_start_klv(&policy);
+
+ with_intel_runtime_pm(>->i915->runtime_pm, wakeref) {
+ u32 yield[] = {
+ GLOBAL_SCHEDULE_POLICY_RC_YIELD_DURATION,
+ GLOBAL_SCHEDULE_POLICY_RC_YIELD_RATIO,
+ };
+
+ __guc_scheduling_policy_add_klv(&policy,
+ GUC_SCHEDULING_POLICIES_KLV_ID_RENDER_COMPUTE_YIELD,
+ yield, ARRAY_SIZE(yield));
+
+ ret = __guc_action_set_scheduling_policies(guc, &policy);
+ if (ret)
+ i915_probe_error(gt->i915,
+ "Failed to configure global scheduling policies: %pe!\n",
+ ERR_PTR(ret));
+ }
+
+ return ret;
+}
+
void intel_guc_submission_enable(struct intel_guc *guc)
{
struct intel_gt *gt = guc_to_gt(guc);
@@ -4189,6 +4281,7 @@ void intel_guc_submission_enable(struct intel_guc *guc)
guc_init_lrc_mapping(guc);
guc_init_engine_stats(guc);
+ guc_init_global_schedule_policy(guc);
}
void intel_guc_submission_disable(struct intel_guc *guc)
--
2.37.3
