[PATCH v2 08/12] drm/xe/exec: Switch hw engine group execution mode upon job submission

[Francois Dugast]

If the job about to be submitted is a dma-fence job, update the current
execution mode of the hw engine group. This triggers the required
operations to ensure mutual exclusion of executions modes in this hw
engine group.

v2: Change execution mode in exec IOCTL only when submitted job is
    dma-fence (Matt Brost)

Signed-off-by: Francois Dugast <francois.dugast at intel.com>
---
 drivers/gpu/drm/xe/xe_exec.c            | 17 ++++++++++++++++-
 drivers/gpu/drm/xe/xe_hw_engine_group.c | 13 +++++++++++++
 drivers/gpu/drm/xe/xe_hw_engine_group.h |  3 +++
 3 files changed, 32 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/xe/xe_exec.c b/drivers/gpu/drm/xe/xe_exec.c
index f36980aa26e6..2169fbf766d3 100644
--- a/drivers/gpu/drm/xe/xe_exec.c
+++ b/drivers/gpu/drm/xe/xe_exec.c
@@ -14,6 +14,7 @@
 #include "xe_bo.h"
 #include "xe_device.h"
 #include "xe_exec_queue.h"
+#include "xe_hw_engine_group.h"
 #include "xe_macros.h"
 #include "xe_ring_ops_types.h"
 #include "xe_sched_job.h"
@@ -124,6 +125,8 @@ int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 	bool write_locked, skip_retry = false;
 	ktime_t end = 0;
 	int err = 0;
+	struct xe_hw_engine_group *group;
+	enum xe_hw_engine_group_execution_mode mode, previous_mode;
 
 	if (XE_IOCTL_DBG(xe, args->extensions) ||
 	    XE_IOCTL_DBG(xe, args->pad[0] || args->pad[1] || args->pad[2]) ||
@@ -182,6 +185,15 @@ int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 		}
 	}
 
+	group = q->hwe->hw_engine_group;
+	mode = xe_hw_engine_group_find_exec_mode(q);
+
+	if (mode == EXEC_MODE_DMA_FENCE) {
+		err = xe_hw_engine_group_get_mode(group, mode, &previous_mode);
+		if (err)
+			goto err_syncs;
+	}
+
 retry:
 	if (!xe_vm_in_lr_mode(vm) && xe_vm_userptr_check_repin(vm)) {
 		err = down_write_killable(&vm->lock);
@@ -199,7 +211,7 @@ int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 		downgrade_write(&vm->lock);
 		write_locked = false;
 		if (err)
-			goto err_unlock_list;
+			goto err_hw_exec_mode;
 	}
 
 	if (!args->num_batch_buffer) {
@@ -324,6 +336,9 @@ int xe_exec_ioctl(struct drm_device *dev, void *data, struct drm_file *file)
 	up_read(&vm->lock);
 	if (err == -EAGAIN && !skip_retry)
 		goto retry;
+err_hw_exec_mode:
+	if (mode == EXEC_MODE_DMA_FENCE)
+		xe_hw_engine_group_put(group);
 err_syncs:
 	while (num_syncs--)
 		xe_sync_entry_cleanup(&syncs[num_syncs]);
diff --git a/drivers/gpu/drm/xe/xe_hw_engine_group.c b/drivers/gpu/drm/xe/xe_hw_engine_group.c
index 19aabaa782b7..de93f94e4cc0 100644
--- a/drivers/gpu/drm/xe/xe_hw_engine_group.c
+++ b/drivers/gpu/drm/xe/xe_hw_engine_group.c
@@ -278,3 +278,16 @@ __releases(&group->mode_sem)
 {
 	up_read(&group->mode_sem);
 }
+
+/**
+ * xe_hw_engine_group_find_exec_mode() - Find the execution mode for this exec queue
+ * @q: The exec_queue
+ */
+enum xe_hw_engine_group_execution_mode
+xe_hw_engine_group_find_exec_mode(struct xe_exec_queue *q)
+{
+	if (xe_vm_in_lr_mode(q->vm))
+		return EXEC_MODE_LR;
+	else
+		return EXEC_MODE_DMA_FENCE;
+}
diff --git a/drivers/gpu/drm/xe/xe_hw_engine_group.h b/drivers/gpu/drm/xe/xe_hw_engine_group.h
index e0deb7c7bb5b..0f196c0ad98d 100644
--- a/drivers/gpu/drm/xe/xe_hw_engine_group.h
+++ b/drivers/gpu/drm/xe/xe_hw_engine_group.h
@@ -22,4 +22,7 @@ int xe_hw_engine_group_get_mode(struct xe_hw_engine_group *group,
 				enum xe_hw_engine_group_execution_mode *previous_mode);
 void xe_hw_engine_group_put(struct xe_hw_engine_group *group);
 
+enum xe_hw_engine_group_execution_mode
+xe_hw_engine_group_find_exec_mode(struct xe_exec_queue *q);
+
 #endif
-- 
2.43.0