[PATCH] dmaengine: idxd: fix wq settings post wq disable

[Dave Jiang <dave.jiang@xxxxxxxxx>]

By the spec, wq size and group association is not changeable unless device
is disabled. Exclude clearing the shadow copy on wq disable/reset. This
allows wq type to be changed after disable to be re-enabled.

Move the size and group association to its own cleanup and only call it
during device disable.

Fixes: 0dcfe41e9a4c ("dmanegine: idxd: cleanup all device related bits after disabling device")
Reported-by: Lucas Van <lucas.van@xxxxxxxxx>
Tested-by: Lucas Van <lucas.van@xxxxxxxxx>
Signed-off-by: Dave Jiang <dave.jiang@xxxxxxxxx>
---
 drivers/dma/idxd/device.c |   12 ++++++++++--
 1 file changed, 10 insertions(+), 2 deletions(-)

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 280b41417f41..3fce7629daa7 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -358,8 +358,6 @@ static void idxd_wq_disable_cleanup(struct idxd_wq *wq)
 	lockdep_assert_held(&wq->wq_lock);
 	memset(wq->wqcfg, 0, idxd->wqcfg_size);
 	wq->type = IDXD_WQT_NONE;
-	wq->size = 0;
-	wq->group = NULL;
 	wq->threshold = 0;
 	wq->priority = 0;
 	wq->ats_dis = 0;
@@ -371,6 +369,15 @@ static void idxd_wq_disable_cleanup(struct idxd_wq *wq)
 	wq->max_batch_size = WQ_DEFAULT_MAX_BATCH;
 }
 
+static void idxd_wq_device_reset_cleanup(struct idxd_wq *wq)
+{
+	lockdep_assert_held(&wq->wq_lock);
+
+	idxd_wq_disable_cleanup(wq);
+	wq->size = 0;
+	wq->group = NULL;
+}
+
 static void idxd_wq_ref_release(struct percpu_ref *ref)
 {
 	struct idxd_wq *wq = container_of(ref, struct idxd_wq, wq_active);
@@ -689,6 +696,7 @@ static void idxd_device_wqs_clear_state(struct idxd_device *idxd)
 
 		if (wq->state == IDXD_WQ_ENABLED) {
 			idxd_wq_disable_cleanup(wq);
+			idxd_wq_device_reset_cleanup(wq);
 			wq->state = IDXD_WQ_DISABLED;
 		}
 	}