1 files changed, 282 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/hfi1/vnic_sdma.c b/drivers/infiniband/hw/hfi1/vnic_sdma.c
new file mode 100644
index 000000000..cc6324d2d
--- /dev/null
+++ b/drivers/infiniband/hw/hfi1/vnic_sdma.c
@@ -0,0 +1,282 @@
+// SPDX-License-Identifier: GPL-2.0 or BSD-3-Clause
+/*
+ * Copyright(c) 2017 - 2018 Intel Corporation.
+ */
+
+/*
+ * This file contains HFI1 support for VNIC SDMA functionality
+ */
+
+#include "sdma.h"
+#include "vnic.h"
+
+#define HFI1_VNIC_SDMA_Q_ACTIVE   BIT(0)
+#define HFI1_VNIC_SDMA_Q_DEFERRED BIT(1)
+
+#define HFI1_VNIC_TXREQ_NAME_LEN   32
+#define HFI1_VNIC_SDMA_DESC_WTRMRK 64
+
+/*
+ * struct vnic_txreq - VNIC transmit descriptor
+ * @txreq: sdma transmit request
+ * @sdma: vnic sdma pointer
+ * @skb: skb to send
+ * @pad: pad buffer
+ * @plen: pad length
+ * @pbc_val: pbc value
+ */
+struct vnic_txreq {
+	struct sdma_txreq       txreq;
+	struct hfi1_vnic_sdma   *sdma;
+
+	struct sk_buff         *skb;
+	unsigned char           pad[HFI1_VNIC_MAX_PAD];
+	u16                     plen;
+	__le64                  pbc_val;
+};
+
+static void vnic_sdma_complete(struct sdma_txreq *txreq,
+			       int status)
+{
+	struct vnic_txreq *tx = container_of(txreq, struct vnic_txreq, txreq);
+	struct hfi1_vnic_sdma *vnic_sdma = tx->sdma;
+
+	sdma_txclean(vnic_sdma->dd, txreq);
+	dev_kfree_skb_any(tx->skb);
+	kmem_cache_free(vnic_sdma->dd->vnic.txreq_cache, tx);
+}
+
+static noinline int build_vnic_ulp_payload(struct sdma_engine *sde,
+					   struct vnic_txreq *tx)
+{
+	int i, ret = 0;
+
+	ret = sdma_txadd_kvaddr(
+		sde->dd,
+		&tx->txreq,
+		tx->skb->data,
+		skb_headlen(tx->skb));
+	if (unlikely(ret))
+		goto bail_txadd;
+
+	for (i = 0; i < skb_shinfo(tx->skb)->nr_frags; i++) {
+		skb_frag_t *frag = &skb_shinfo(tx->skb)->frags[i];
+
+		/* combine physically continuous fragments later? */
+		ret = sdma_txadd_page(sde->dd,
+				      &tx->txreq,
+				      skb_frag_page(frag),
+				      skb_frag_off(frag),
+				      skb_frag_size(frag),
+				      NULL, NULL, NULL);
+		if (unlikely(ret))
+			goto bail_txadd;
+	}
+
+	if (tx->plen)
+		ret = sdma_txadd_kvaddr(sde->dd, &tx->txreq,
+					tx->pad + HFI1_VNIC_MAX_PAD - tx->plen,
+					tx->plen);
+
+bail_txadd:
+	return ret;
+}
+
+static int build_vnic_tx_desc(struct sdma_engine *sde,
+			      struct vnic_txreq *tx,
+			      u64 pbc)
+{
+	int ret = 0;
+	u16 hdrbytes = 2 << 2;  /* PBC */
+
+	ret = sdma_txinit_ahg(
+		&tx->txreq,
+		0,
+		hdrbytes + tx->skb->len + tx->plen,
+		0,
+		0,
+		NULL,
+		0,
+		vnic_sdma_complete);
+	if (unlikely(ret))
+		goto bail_txadd;
+
+	/* add pbc */
+	tx->pbc_val = cpu_to_le64(pbc);
+	ret = sdma_txadd_kvaddr(
+		sde->dd,
+		&tx->txreq,
+		&tx->pbc_val,
+		hdrbytes);
+	if (unlikely(ret))
+		goto bail_txadd;
+
+	/* add the ulp payload */
+	ret = build_vnic_ulp_payload(sde, tx);
+bail_txadd:
+	return ret;
+}
+
+/* setup the last plen bypes of pad */
+static inline void hfi1_vnic_update_pad(unsigned char *pad, u8 plen)
+{
+	pad[HFI1_VNIC_MAX_PAD - 1] = plen - OPA_VNIC_ICRC_TAIL_LEN;
+}
+
+int hfi1_vnic_send_dma(struct hfi1_devdata *dd, u8 q_idx,
+		       struct hfi1_vnic_vport_info *vinfo,
+		       struct sk_buff *skb, u64 pbc, u8 plen)
+{
+	struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[q_idx];
+	struct sdma_engine *sde = vnic_sdma->sde;
+	struct vnic_txreq *tx;
+	int ret = -ECOMM;
+
+	if (unlikely(READ_ONCE(vnic_sdma->state) != HFI1_VNIC_SDMA_Q_ACTIVE))
+		goto tx_err;
+
+	if (unlikely(!sde || !sdma_running(sde)))
+		goto tx_err;
+
+	tx = kmem_cache_alloc(dd->vnic.txreq_cache, GFP_ATOMIC);
+	if (unlikely(!tx)) {
+		ret = -ENOMEM;
+		goto tx_err;
+	}
+
+	tx->sdma = vnic_sdma;
+	tx->skb = skb;
+	hfi1_vnic_update_pad(tx->pad, plen);
+	tx->plen = plen;
+	ret = build_vnic_tx_desc(sde, tx, pbc);
+	if (unlikely(ret))
+		goto free_desc;
+
+	ret = sdma_send_txreq(sde, iowait_get_ib_work(&vnic_sdma->wait),
+			      &tx->txreq, vnic_sdma->pkts_sent);
+	/* When -ECOMM, sdma callback will be called with ABORT status */
+	if (unlikely(ret && unlikely(ret != -ECOMM)))
+		goto free_desc;
+
+	if (!ret) {
+		vnic_sdma->pkts_sent = true;
+		iowait_starve_clear(vnic_sdma->pkts_sent, &vnic_sdma->wait);
+	}
+	return ret;
+
+free_desc:
+	sdma_txclean(dd, &tx->txreq);
+	kmem_cache_free(dd->vnic.txreq_cache, tx);
+tx_err:
+	if (ret != -EBUSY)
+		dev_kfree_skb_any(skb);
+	else
+		vnic_sdma->pkts_sent = false;
+	return ret;
+}
+
+/*
+ * hfi1_vnic_sdma_sleep - vnic sdma sleep function
+ *
+ * This function gets called from sdma_send_txreq() when there are not enough
+ * sdma descriptors available to send the packet. It adds Tx queue's wait
+ * structure to sdma engine's dmawait list to be woken up when descriptors
+ * become available.
+ */
+static int hfi1_vnic_sdma_sleep(struct sdma_engine *sde,
+				struct iowait_work *wait,
+				struct sdma_txreq *txreq,
+				uint seq,
+				bool pkts_sent)
+{
+	struct hfi1_vnic_sdma *vnic_sdma =
+		container_of(wait->iow, struct hfi1_vnic_sdma, wait);
+
+	write_seqlock(&sde->waitlock);
+	if (sdma_progress(sde, seq, txreq)) {
+		write_sequnlock(&sde->waitlock);
+		return -EAGAIN;
+	}
+
+	vnic_sdma->state = HFI1_VNIC_SDMA_Q_DEFERRED;
+	if (list_empty(&vnic_sdma->wait.list)) {
+		iowait_get_priority(wait->iow);
+		iowait_queue(pkts_sent, wait->iow, &sde->dmawait);
+	}
+	write_sequnlock(&sde->waitlock);
+	return -EBUSY;
+}
+
+/*
+ * hfi1_vnic_sdma_wakeup - vnic sdma wakeup function
+ *
+ * This function gets called when SDMA descriptors becomes available and Tx
+ * queue's wait structure was previously added to sdma engine's dmawait list.
+ * It notifies the upper driver about Tx queue wakeup.
+ */
+static void hfi1_vnic_sdma_wakeup(struct iowait *wait, int reason)
+{
+	struct hfi1_vnic_sdma *vnic_sdma =
+		container_of(wait, struct hfi1_vnic_sdma, wait);
+	struct hfi1_vnic_vport_info *vinfo = vnic_sdma->vinfo;
+
+	vnic_sdma->state = HFI1_VNIC_SDMA_Q_ACTIVE;
+	if (__netif_subqueue_stopped(vinfo->netdev, vnic_sdma->q_idx))
+		netif_wake_subqueue(vinfo->netdev, vnic_sdma->q_idx);
+};
+
+inline bool hfi1_vnic_sdma_write_avail(struct hfi1_vnic_vport_info *vinfo,
+				       u8 q_idx)
+{
+	struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[q_idx];
+
+	return (READ_ONCE(vnic_sdma->state) == HFI1_VNIC_SDMA_Q_ACTIVE);
+}
+
+void hfi1_vnic_sdma_init(struct hfi1_vnic_vport_info *vinfo)
+{
+	int i;
+
+	for (i = 0; i < vinfo->num_tx_q; i++) {
+		struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[i];
+
+		iowait_init(&vnic_sdma->wait, 0, NULL, NULL,
+			    hfi1_vnic_sdma_sleep,
+			    hfi1_vnic_sdma_wakeup, NULL, NULL);
+		vnic_sdma->sde = &vinfo->dd->per_sdma[i];
+		vnic_sdma->dd = vinfo->dd;
+		vnic_sdma->vinfo = vinfo;
+		vnic_sdma->q_idx = i;
+		vnic_sdma->state = HFI1_VNIC_SDMA_Q_ACTIVE;
+
+		/* Add a free descriptor watermark for wakeups */
+		if (vnic_sdma->sde->descq_cnt > HFI1_VNIC_SDMA_DESC_WTRMRK) {
+			struct iowait_work *work;
+
+			INIT_LIST_HEAD(&vnic_sdma->stx.list);
+			vnic_sdma->stx.num_desc = HFI1_VNIC_SDMA_DESC_WTRMRK;
+			work = iowait_get_ib_work(&vnic_sdma->wait);
+			list_add_tail(&vnic_sdma->stx.list, &work->tx_head);
+		}
+	}
+}
+
+int hfi1_vnic_txreq_init(struct hfi1_devdata *dd)
+{
+	char buf[HFI1_VNIC_TXREQ_NAME_LEN];
+
+	snprintf(buf, sizeof(buf), "hfi1_%u_vnic_txreq_cache", dd->unit);
+	dd->vnic.txreq_cache = kmem_cache_create(buf,
+						 sizeof(struct vnic_txreq),
+						 0, SLAB_HWCACHE_ALIGN,
+						 NULL);
+	if (!dd->vnic.txreq_cache)
+		return -ENOMEM;
+	return 0;
+}
+
+void hfi1_vnic_txreq_deinit(struct hfi1_devdata *dd)
+{
+	kmem_cache_destroy(dd->vnic.txreq_cache);
+	dd->vnic.txreq_cache = NULL;
+}