Commit 23a50c80 authored by Dave Jiang's avatar Dave Jiang Committed by Vinod Koul
Browse files

dmaengine: idxd: fix descriptor flushing locking 



The descriptor flushing for shutdown is not holding the irq_entry list
lock. If there's ongoing interrupt completion handling, this can corrupt
the list. Add locking to protect list walking. Also refactor the code so
it's more compact.

Fixes: 8f47d1a5 ("dmaengine: idxd: connect idxd to dmaengine subsystem")
Signed-off-by: default avatarDave Jiang <dave.jiang@intel.com>
Link: https://lore.kernel.org/r/163942148935.2412839.18282664745572777280.stgit@djiang5-desk3.ch.intel.com


Signed-off-by: default avatarVinod Koul <vkoul@kernel.org>
parent ec0d6423

drivers/dma/idxd/init.c

+15 −14
Original line number Diff line number Diff line
@@ -689,26 +689,28 @@ static int idxd_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id) 
	return rc;

}



static void idxd_flush_pending_llist(struct idxd_irq_entry *ie)

static void idxd_flush_pending_descs(struct idxd_irq_entry *ie)

{

	struct idxd_desc *desc, *itr;

	struct llist_node *head;

	LIST_HEAD(flist);

	enum idxd_complete_type ctype;



	spin_lock(&ie->list_lock);

	head = llist_del_all(&ie->pending_llist);

	if (!head)

		return;



	if (head) {

		llist_for_each_entry_safe(desc, itr, head, llnode)

		idxd_dma_complete_txd(desc, IDXD_COMPLETE_ABORT, true);

			list_add_tail(&desc->list, &ie->work_list);

	}



static void idxd_flush_work_list(struct idxd_irq_entry *ie)

{

	struct idxd_desc *desc, *iter;

	list_for_each_entry_safe(desc, itr, &ie->work_list, list)

		list_move_tail(&desc->list, &flist);

	spin_unlock(&ie->list_lock);



	list_for_each_entry_safe(desc, iter, &ie->work_list, list) {

	list_for_each_entry_safe(desc, itr, &flist, list) {

		list_del(&desc->list);

		idxd_dma_complete_txd(desc, IDXD_COMPLETE_ABORT, true);

		ctype = desc->completion->status ? IDXD_COMPLETE_NORMAL : IDXD_COMPLETE_ABORT;

		idxd_dma_complete_txd(desc, ctype, true);

	}

}
@@ -762,8 +764,7 @@ static void idxd_shutdown(struct pci_dev *pdev) 
		synchronize_irq(irq_entry->vector);

		if (i == 0)

			continue;

		idxd_flush_pending_llist(irq_entry);

		idxd_flush_work_list(irq_entry);

		idxd_flush_pending_descs(irq_entry);

	}

	flush_workqueue(idxd->wq);

}