[PATCH v2 14/34] drm/xe/vf: Remove memory allocations from VF post migration recovery

[Matthew Brost <matthew.brost@intel.com>]

VF post migration recovery is the path of dma-fence signaling / reclaim,
avoid memory allocations in this path.

Signed-off-by: Matthew Brost <matthew.brost@intel.com>
---
 drivers/gpu/drm/xe/xe_gt_sriov_vf.c       | 29 ++++++++++++++---------
 drivers/gpu/drm/xe/xe_gt_sriov_vf.h       |  2 +-
 drivers/gpu/drm/xe/xe_gt_sriov_vf_types.h |  2 ++
 drivers/gpu/drm/xe/xe_sriov.c             |  8 +++++--
 drivers/gpu/drm/xe/xe_sriov_vf.c          | 14 ++++++++---
 drivers/gpu/drm/xe/xe_sriov_vf.h          |  2 +-
 6 files changed, 39 insertions(+), 18 deletions(-)

diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_vf.c b/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
index cfb71b749e52..8304c26c076e 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_vf.c
@@ -1214,17 +1214,13 @@ static size_t post_migration_scratch_size(struct xe_device *xe)
 
 static int vf_post_migration_fixups(struct xe_gt *gt)
 {
+	void *buf = gt->sriov.vf.migration.lrc_wa_bb;
 	s64 shift;
-	void *buf;
 	int err;
 
-	buf = kmalloc(post_migration_scratch_size(gt_to_xe(gt)), GFP_ATOMIC);
-	if (!buf)
-		return -ENOMEM;
-
 	err = xe_gt_sriov_vf_query_config(gt);
 	if (err)
-		goto out;
+		return err;
 
 	shift = xe_gt_sriov_vf_ggtt_shift(gt);
 	if (shift) {
@@ -1232,12 +1228,10 @@ static int vf_post_migration_fixups(struct xe_gt *gt)
 		xe_gt_sriov_vf_default_lrcs_hwsp_rebase(gt);
 		err = xe_guc_contexts_hwsp_rebase(&gt->uc.guc, buf);
 		if (err)
-			goto out;
+			return err;
 	}
 
-out:
-	kfree(buf);
-	return err;
+	return 0;
 }
 
 static void vf_post_migration_kickstart(struct xe_gt *gt)
@@ -1314,15 +1308,28 @@ static void migration_worker_func(struct work_struct *w)
 /**
  * xe_gt_sriov_vf_migration_init_early() - VF post migration init early
  * @gt: the &xe_gt
+ *
+ * Return 0 on success, errno on failure
  */
-void xe_gt_sriov_vf_migration_init_early(struct xe_gt *gt)
+int xe_gt_sriov_vf_migration_init_early(struct xe_gt *gt)
 {
+	void *buf;
+
+	buf = drmm_kmalloc(&gt_to_xe(gt)->drm,
+			   post_migration_scratch_size(gt_to_xe(gt)),
+			   GFP_KERNEL);
+	if (!buf)
+		return -ENOMEM;
+
+	gt->sriov.vf.migration.lrc_wa_bb = buf;
 	init_rwsem(&gt->sriov.vf.self_config.lock);
 	spin_lock_init(&gt->sriov.vf.migration.lock);
 	INIT_WORK(&gt->sriov.vf.migration.worker, migration_worker_func);
 
 	if (!xe_sriov_vf_migration_supported(gt_to_xe(gt)))
 		xe_gt_sriov_info(gt, "migration not supported by this module version\n");
+
+	return 0;
 }
 
 /**
diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_vf.h b/drivers/gpu/drm/xe/xe_gt_sriov_vf.h
index 2ac6775b52f0..195dbebe941e 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_vf.h
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_vf.h
@@ -23,7 +23,7 @@ int xe_gt_sriov_vf_connect(struct xe_gt *gt);
 int xe_gt_sriov_vf_query_runtime(struct xe_gt *gt);
 void xe_gt_sriov_vf_migrated_event_handler(struct xe_gt *gt);
 
-void xe_gt_sriov_vf_migration_init_early(struct xe_gt *gt);
+int xe_gt_sriov_vf_migration_init_early(struct xe_gt *gt);
 bool xe_gt_sriov_vf_recovery_inprogress(struct xe_gt *gt);
 
 u32 xe_gt_sriov_vf_gmdid(struct xe_gt *gt);
diff --git a/drivers/gpu/drm/xe/xe_gt_sriov_vf_types.h b/drivers/gpu/drm/xe/xe_gt_sriov_vf_types.h
index 53680a2f188a..496b657119de 100644
--- a/drivers/gpu/drm/xe/xe_gt_sriov_vf_types.h
+++ b/drivers/gpu/drm/xe/xe_gt_sriov_vf_types.h
@@ -58,6 +58,8 @@ struct xe_gt_sriov_vf_migration {
 	struct work_struct worker;
 	/** @lock: Protects recovery_queued */
 	spinlock_t lock;
+	/** @lrc_wa_bb: Scratch memory for LRC WA BB in recovery */
+	void *lrc_wa_bb;
 	/** @recovery_queued: VF post migration recovery in queued */
 	bool recovery_queued;
 	/** @recovery_inprogress: VF post migration recovery in progress */
diff --git a/drivers/gpu/drm/xe/xe_sriov.c b/drivers/gpu/drm/xe/xe_sriov.c
index 7d2d6de2aabf..358a35c80d5a 100644
--- a/drivers/gpu/drm/xe/xe_sriov.c
+++ b/drivers/gpu/drm/xe/xe_sriov.c
@@ -116,8 +116,12 @@ int xe_sriov_init(struct xe_device *xe)
 			return err;
 	}
 
-	if (IS_SRIOV_VF(xe))
-		xe_sriov_vf_init_early(xe);
+	if (IS_SRIOV_VF(xe)) {
+		int err = xe_sriov_vf_init_early(xe);
+
+		if (err)
+			return err;
+	}
 
 	xe_assert(xe, !xe->sriov.wq);
 	xe->sriov.wq = alloc_workqueue("xe-sriov-wq", 0, 0);
diff --git a/drivers/gpu/drm/xe/xe_sriov_vf.c b/drivers/gpu/drm/xe/xe_sriov_vf.c
index 7d91553c4acc..e622a7c562c4 100644
--- a/drivers/gpu/drm/xe/xe_sriov_vf.c
+++ b/drivers/gpu/drm/xe/xe_sriov_vf.c
@@ -180,16 +180,24 @@ static void vf_migration_init_early(struct xe_device *xe)
 /**
  * xe_sriov_vf_init_early - Initialize SR-IOV VF specific data.
  * @xe: the &xe_device to initialize
+ *
+ * Return: 0 on success or a negative error code on failure.
  */
-void xe_sriov_vf_init_early(struct xe_device *xe)
+int xe_sriov_vf_init_early(struct xe_device *xe)
 {
 	struct xe_gt *gt;
 	unsigned int id;
+	int err;
 
-	for_each_gt(gt, xe, id)
-		xe_gt_sriov_vf_migration_init_early(gt);
+	for_each_gt(gt, xe, id) {
+		err = xe_gt_sriov_vf_migration_init_early(gt);
+		if (err)
+			return err;
+	}
 
 	vf_migration_init_early(xe);
+
+	return 0;
 }
 
 /**
diff --git a/drivers/gpu/drm/xe/xe_sriov_vf.h b/drivers/gpu/drm/xe/xe_sriov_vf.h
index 4df95266b261..13969c6910ce 100644
--- a/drivers/gpu/drm/xe/xe_sriov_vf.h
+++ b/drivers/gpu/drm/xe/xe_sriov_vf.h
@@ -11,7 +11,7 @@
 struct dentry;
 struct xe_device;
 
-void xe_sriov_vf_init_early(struct xe_device *xe);
+int xe_sriov_vf_init_early(struct xe_device *xe);
 int xe_sriov_vf_init_late(struct xe_device *xe);
 bool xe_sriov_vf_migration_supported(struct xe_device *xe);
 void xe_sriov_vf_debugfs_register(struct xe_device *xe, struct dentry *root);
-- 
2.34.1