1 files changed, 96 insertions, 0 deletions
diff --git a/drivers/dma/idxd/submit.c b/drivers/dma/idxd/submit.c
new file mode 100644
index 000000000000..6856445b5ab2
--- /dev/null
+++ b/drivers/dma/idxd/submit.c
@@ -0,0 +1,96 @@
+// SPDX-License-Identifier: GPL-2.0
+/* Copyright(c) 2019 Intel Corporation. All rights rsvd. */
+#include <linux/init.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/pci.h>
+#include <uapi/linux/idxd.h>
+#include <linux/sched/signal.h>
+#include "idxd.h"
+#include "registers.h"
+
+static struct idxd_desc *__get_desc(struct idxd_wq *wq, int idx, int cpu)
+{
+	struct idxd_desc *desc;
+
+	desc = wq->descs[idx];
+	memset(desc->hw, 0, sizeof(struct dsa_hw_desc));
+	memset(desc->completion, 0, sizeof(struct dsa_completion_record));
+	desc->cpu = cpu;
+	return desc;
+}
+
+struct idxd_desc *idxd_alloc_desc(struct idxd_wq *wq, enum idxd_op_type optype)
+{
+	int cpu, idx;
+	struct idxd_device *idxd = wq->idxd;
+	DEFINE_SBQ_WAIT(wait);
+	struct sbq_wait_state *ws;
+	struct sbitmap_queue *sbq;
+
+	if (idxd->state != IDXD_DEV_ENABLED)
+		return ERR_PTR(-EIO);
+
+	sbq = &wq->sbq;
+	idx = sbitmap_queue_get(sbq, &cpu);
+	if (idx < 0) {
+		if (optype == IDXD_OP_NONBLOCK)
+			return ERR_PTR(-EAGAIN);
+	} else {
+		return __get_desc(wq, idx, cpu);
+	}
+
+	ws = &sbq->ws[0];
+	for (;;) {
+		sbitmap_prepare_to_wait(sbq, ws, &wait, TASK_INTERRUPTIBLE);
+		if (signal_pending_state(TASK_INTERRUPTIBLE, current))
+			break;
+		idx = sbitmap_queue_get(sbq, &cpu);
+		if (idx > 0)
+			break;
+		schedule();
+	}
+
+	sbitmap_finish_wait(sbq, ws, &wait);
+	if (idx < 0)
+		return ERR_PTR(-EAGAIN);
+
+	return __get_desc(wq, idx, cpu);
+}
+
+void idxd_free_desc(struct idxd_wq *wq, struct idxd_desc *desc)
+{
+	int cpu = desc->cpu;
+
+	desc->cpu = -1;
+	sbitmap_queue_clear(&wq->sbq, desc->id, cpu);
+}
+
+int idxd_submit_desc(struct idxd_wq *wq, struct idxd_desc *desc)
+{
+	struct idxd_device *idxd = wq->idxd;
+	int vec = desc->hw->int_handle;
+	void __iomem *portal;
+
+	if (idxd->state != IDXD_DEV_ENABLED)
+		return -EIO;
+
+	portal = wq->dportal;
+	/*
+	 * The wmb() flushes writes to coherent DMA data before possibly
+	 * triggering a DMA read. The wmb() is necessary even on UP because
+	 * the recipient is a device.
+	 */
+	wmb();
+	iosubmit_cmds512(portal, desc->hw, 1);
+
+	/*
+	 * Pending the descriptor to the lockless list for the irq_entry
+	 * that we designated the descriptor to.
+	 */
+	if (desc->hw->flags & IDXD_OP_FLAG_RCI)
+		llist_add(&desc->llnode,
+			  &idxd->irq_entries[vec].pending_llist);
+
+	return 0;
+}