[v2] IB/hfi1: Fix sleep inside atomic issue in init_asic_data

Commit Message

Marciniszyn, Mike July 6, 2016, 4:25 p.m. UTC

From: Tadeusz Struk <[e-mail]>

The critical section should protect only the list traversal
and dd->asic_data modification, not the memory allocation.
The fix pulls the allocation out of the critical section.

Reviewed-by: Dennis Dalessandro <[e-mail]>
Reviewed-by: Sebastian Sanchez <[e-mail]>
Reviewed-by: Dean Luick <[e-mail]>
Signed-off-by: Tadeusz Struk <[e-mail]>
Signed-off-by: Dennis Dalessandro <[e-mail]>
---
 v2 - fix syntax error due to bad conflict resolution

 drivers/infiniband/hw/hfi1/chip.c |   16 +++++++++-------
 1 file changed, 9 insertions(+), 7 deletions(-)


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Patch

diff --git a/drivers/infiniband/hw/hfi1/chip.c b/drivers/infiniband/hw/hfi1/chip.c
index f5de851..dad4d0e 100644
--- a/drivers/infiniband/hw/hfi1/chip.c
+++ b/drivers/infiniband/hw/hfi1/chip.c
@@ -14113,8 +14113,14 @@  static int init_asic_data(struct hfi1_devdata *dd)
 {
 	unsigned long flags;
 	struct hfi1_devdata *tmp, *peer = NULL;
+	struct hfi1_asic_data *asic_data;
 	int ret = 0;
 
+	/* pre-allocate the asic structure in case we are the first device */
+	asic_data = kzalloc(sizeof(*dd->asic_data), GFP_KERNEL);
+	if (!asic_data)
+		return -ENOMEM;
+
 	spin_lock_irqsave(&hfi1_devs_lock, flags);
 	/* Find our peer device */
 	list_for_each_entry(tmp, &hfi1_dev_list, list) {
@@ -14126,18 +14132,14 @@  static int init_asic_data(struct hfi1_devdata *dd)
 	}
 
 	if (peer) {
+		/* use already allocated structure */
 		dd->asic_data = peer->asic_data;
+		kfree(asic_data);
 	} else {
-		dd->asic_data = kzalloc(sizeof(*dd->asic_data), GFP_KERNEL);
-		if (!dd->asic_data) {
-			ret = -ENOMEM;
-			goto done;
-		}
+		dd->asic_data = asic_data;
 		mutex_init(&dd->asic_data->asic_resource_mutex);
 	}
 	dd->asic_data->dds[dd->hfi1_id] = dd; /* self back-pointer */
-
-done:
 	spin_unlock_irqrestore(&hfi1_devs_lock, flags);
 	return ret;
 }