[Patch v2] drm/amdkfd: Fix CRIU restore op due to doorbell offset

[Rajneesh Bhardwaj]

Recently introduced change to allocate doorbells only when the first
queue is created or mapped for CPU / GPU access, did not consider
Checkpoint Restore scenario completely. This fix allows the CRIU restore
operation by extending the doorbell optimization to CRIU restore
scenario.

Fixes: 'commit 15bcfbc55b57 ("drm/amdkfd: Allocate doorbells only when needed")'

Signed-off-by: Rajneesh Bhardwaj <rajneesh.bhardwaj at amd.com>
---

Changes in v2:

* Addressed review feedback from Felix

 drivers/gpu/drm/amd/amdkfd/kfd_chardev.c               | 6 ++++++
 drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c              | 3 +++
 drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c | 7 +++++++
 3 files changed, 16 insertions(+)

diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
index 84da1a9ce37c..56f7307c21d2 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_chardev.c
@@ -2153,6 +2153,12 @@ static int criu_restore_devices(struct kfd_process *p,
 			ret = PTR_ERR(pdd);
 			goto exit;
 		}
+
+		if (!pdd->doorbell_index &&
+		    kfd_alloc_process_doorbells(pdd->dev, &pdd->doorbell_index) < 0) {
+			ret = -ENOMEM;
+			goto exit;
+		}
 	}
 
 	/*
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c b/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
index b33798f89ef0..cd4e61bf0493 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_doorbell.c
@@ -303,6 +303,9 @@ int kfd_alloc_process_doorbells(struct kfd_dev *kfd, unsigned int *doorbell_inde
 	if (r > 0)
 		*doorbell_index = r;
 
+	if (r < 0)
+		pr_err("Failed to allocate process doorbells\n");
+
 	return r;
 }
 
diff --git a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
index 6e3e7f54381b..5137476ec18e 100644
--- a/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
+++ b/drivers/gpu/drm/amd/amdkfd/kfd_process_queue_manager.c
@@ -857,6 +857,13 @@ int kfd_criu_restore_queue(struct kfd_process *p,
 		ret = -EINVAL;
 		goto exit;
 	}
+
+	if (!pdd->doorbell_index &&
+	    kfd_alloc_process_doorbells(pdd->dev, &pdd->doorbell_index) < 0) {
+		ret = -ENOMEM;
+		goto exit;
+	}
+
 	/* data stored in this order: mqd, ctl_stack */
 	mqd = q_extra_data;
 	ctl_stack = mqd + q_data->mqd_size;
-- 
2.17.1