[Intel-xe] [PATCH v3 3/3] drm/xe/pvc: Use fast copy engines as migrate engine on PVC

[Niranjana Vishwanathapura]

Some copy hardware engine instances are faster than others on PVC.
Use a virtual engine of these plus the reserved instance for the migrate
engine on PVC. The idea being if a fast instance is available it will be
used and the throughput of kernel copies, clears, and pagefault
servicing will be higher.

v2: Use OOB WA, use all copy engines if no WA is required

Signed-off-by: Matthew Brost <matthew.brost at intel.com>
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura at intel.com>
---
 drivers/gpu/drm/xe/xe_migrate.c    | 39 +++++++++++++++++++++++++++---
 drivers/gpu/drm/xe/xe_wa_oob.rules |  1 +
 2 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_migrate.c b/drivers/gpu/drm/xe/xe_migrate.c
index 956a96b38346..60f4e0a60b71 100644
--- a/drivers/gpu/drm/xe/xe_migrate.c
+++ b/drivers/gpu/drm/xe/xe_migrate.c
@@ -12,6 +12,7 @@
 #include <drm/ttm/ttm_tt.h>
 #include <drm/xe_drm.h>
 
+#include "generated/xe_wa_oob.h"
 #include "regs/xe_gpu_commands.h"
 #include "tests/xe_test.h"
 #include "xe_bb.h"
@@ -29,6 +30,7 @@
 #include "xe_sync.h"
 #include "xe_trace.h"
 #include "xe_vm.h"
+#include "xe_wa.h"
 
 /**
  * struct xe_migrate - migrate context.
@@ -298,6 +300,36 @@ static int xe_migrate_prepare_vm(struct xe_tile *tile, struct xe_migrate *m,
 	return 0;
 }
 
+/**
+ * xe_migrate_usm_logical_mask - Return logical mask for usm migrate engine.
+ * @gt: gt instance
+ *
+ * Due to workaround 16017236439, odd instance hardware copy engines are
+ * faster than even instance ones.
+ * This function returns the mask involving all faster copy engines and the
+ * reserved copy engine to be used as logical mask for migrate engine.
+ * Including the reserved copy engine is required to avoid deadlocks due to
+ * migrate jobs servicing the faults gets stuck behind the job that faulted.
+ */
+u32 xe_migrate_usm_logical_mask(struct xe_gt *gt)
+{
+	u32 logical_mask = 0;
+	struct xe_hw_engine *hwe;
+	enum xe_hw_engine_id id;
+
+	for_each_hw_engine(hwe, gt, id) {
+		if (hwe->class != XE_ENGINE_CLASS_COPY)
+			continue;
+
+		if (!XE_WA(gt, 16017236439) ||
+		    xe_gt_is_usm_hwe(gt, hwe) || hwe->instance & 1)
+			logical_mask |= BIT(hwe->logical_instance);
+	}
+
+	pr_info("NNV %s logical_mask 0x%x\n", __func__, logical_mask);
+	return logical_mask;
+}
+
 /**
  * xe_migrate_init() - Initialize a migrate context
  * @tile: Back-pointer to the tile we're initializing for.
@@ -338,11 +370,12 @@ struct xe_migrate *xe_migrate_init(struct xe_tile *tile)
 							   XE_ENGINE_CLASS_COPY,
 							   primary_gt->usm.reserved_bcs_instance,
 							   false);
-		if (!hwe)
+		u32 logical_mask = xe_migrate_usm_logical_mask(primary_gt);
+
+		if (!hwe || !logical_mask)
 			return ERR_PTR(-EINVAL);
 
-		m->q = xe_exec_queue_create(xe, vm,
-					    BIT(hwe->logical_instance), 1,
+		m->q = xe_exec_queue_create(xe, vm, logical_mask, 1,
 					    hwe, EXEC_QUEUE_FLAG_KERNEL);
 	} else {
 		m->q = xe_exec_queue_create_class(xe, primary_gt, vm,
diff --git a/drivers/gpu/drm/xe/xe_wa_oob.rules b/drivers/gpu/drm/xe/xe_wa_oob.rules
index ea90dcc933b5..599e67169dae 100644
--- a/drivers/gpu/drm/xe/xe_wa_oob.rules
+++ b/drivers/gpu/drm/xe/xe_wa_oob.rules
@@ -17,3 +17,4 @@
 1409600907	GRAPHICS_VERSION_RANGE(1200, 1250)
 14016763929	SUBPLATFORM(DG2, G10)
 		SUBPLATFORM(DG2, G12)
+16017236439	PLATFORM(PVC)
-- 
2.21.0.rc0.32.g243a4c7e27