[RFC 10/10] IB/hfi1: VNIC SDMA support

Vishwanathapura, Niranjana
2016-11-18T22:42:18Z

HFI1 VNIC SDMA support enables transmission of VNIC packets over SDMA.
Map VNIC queues to SDMA engines and support halting and wakeup of the
VNIC queues.

Change-Id: I2d2d23bda9fb8a7194d9722e23bc69b110cdcf86
Reviewed-by: Dennis Dalessandro <dennis.dalessandro-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Niranjana Vishwanathapura <niranjana.vishwanathapura-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
drivers/infiniband/hw/hfi1/hfi.h | 1 +
drivers/infiniband/hw/hfi1/vnic.h | 30 +++-
drivers/infiniband/hw/hfi1/vnic_device.c | 2 +-
drivers/infiniband/hw/hfi1/vnic_main.c | 22 ++-
drivers/infiniband/hw/hfi1/vnic_sdma.c | 260 +++++++++++++++++++++++++++++++
5 files changed, 311 insertions(+), 4 deletions(-)

diff --git a/drivers/infiniband/hw/hfi1/hfi.h b/drivers/infiniband/hw/hfi1/hfi.h
index 2ff3453..f476188 100644
--- a/drivers/infiniband/hw/hfi1/hfi.h
+++ b/drivers/infiniband/hw/hfi1/hfi.h
@@ -855,6 +855,7 @@ struct hfi1_asic_data {
/* Virtual NIC information */
struct hfi1_vnic_data {
struct hfi1_ctxtdata *ctxt[HFI1_NUM_VNIC_CTXT];
+ struct kmem_cache *txreq_cache;
u8 num_vports;
struct hfi_vnic_ctrl_device *ctrl_dev;
struct idr vesw_idr;
diff --git a/drivers/infiniband/hw/hfi1/vnic.h b/drivers/infiniband/hw/hfi1/vnic.h
index d91c35b..4bdfe2b 100644
--- a/drivers/infiniband/hw/hfi1/vnic.h
+++ b/drivers/infiniband/hw/hfi1/vnic.h
@@ -49,6 +49,7 @@

#include "hfi_vnic.h"
#include "hfi.h"
+#include "sdma.h"

#define HFI1_VNIC_ICRC_LEN 4
#define HFI1_VNIC_TAIL_LEN 1
@@ -90,6 +91,26 @@
#define HFI1_VNIC_SC_SHIFT 4

/**
+ * struct hfi1_vnic_sdma - VNIC per Tx ring SDMA information
+ * @dd - device data pointer
+ * @sde - sdma engine
+ * @vinfo - vnic info pointer
+ * @wait - iowait structure
+ * @stx - sdma tx request
+ * @state - vnic Tx ring SDMA state
+ * @q_idx - vnic Tx queue index
+ */
+struct hfi1_vnic_sdma {
+ struct hfi1_devdata *dd;
+ struct sdma_engine *sde;
+ struct hfi1_vnic_vport_info *vinfo;
+ struct iowait wait;
+ struct sdma_txreq stx;
+ unsigned int state;
+ u8 q_idx;
+};
+
+/**
* struct hfi1_vnic_notifier - VNIC notifer structure
* @cb - vnic callback function
*/
@@ -104,6 +125,7 @@ struct hfi1_vnic_notifier {
* @event_flags: event notification flags
* @notifier: vnic notifier
* @skbq: Array of queues for received socket buffers
+ * @sdma: VNIC SDMA structure per TXQ
*/
struct hfi1_vnic_vport_info {
struct hfi1_devdata *dd;
@@ -112,7 +134,8 @@ struct hfi1_vnic_vport_info {
DECLARE_BITMAP(event_flags, HFI_VNIC_NUM_EVTS);
struct hfi_vnic_device *vdev;

- struct sk_buff_head skbq[HFI1_NUM_VNIC_CTXT];
+ struct sk_buff_head skbq[HFI1_NUM_VNIC_CTXT];
+ struct hfi1_vnic_sdma sdma[HFI1_VNIC_MAX_TXQ];
};

static inline struct hfi1_devdata *vnic_dev2dd(struct hfi_vnic_device *vdev)
@@ -131,10 +154,15 @@ static inline void hfi1_vnic_update_pad(unsigned char *pad, u8 plen)
/* vnic hfi1 internal functions */
int hfi1_vnic_setup(struct hfi1_devdata *dd);
void hfi1_vnic_cleanup(struct hfi1_devdata *dd);
+int hfi1_vnic_txreq_init(struct hfi1_devdata *dd);
+void hfi1_vnic_txreq_deinit(struct hfi1_devdata *dd);
int hfi1_vnic_add_ctrl_port(struct hfi1_devdata *dd, struct device *parent);
void hfi1_vnic_rem_ctrl_port(struct hfi1_devdata *dd);

void hfi1_vnic_bypass_rcv(struct hfi1_packet *packet);
+void hfi1_vnic_sdma_init(struct hfi1_vnic_vport_info *vinfo);
+bool hfi1_vnic_sdma_write_avail(struct hfi1_vnic_vport_info *vinfo,
+ u8 q_idx);

/* vnic device bus ops */
int hfi1_vnic_init(struct hfi_vnic_device *vdev);
diff --git a/drivers/infiniband/hw/hfi1/vnic_device.c b/drivers/infiniband/hw/hfi1/vnic_device.c
index 468e197..5fb1a49 100644
--- a/drivers/infiniband/hw/hfi1/vnic_device.c
+++ b/drivers/infiniband/hw/hfi1/vnic_device.c
@@ -85,7 +85,7 @@ static int hfi1_vdev_create(struct hfi_vnic_ctrl_device *cdev,
return -ENOMEM;

vinfo->dd = dd;
- hfi_info.num_tx_q = 1;
+ hfi_info.num_tx_q = dd->chip_sdma_engines;
hfi_info.num_rx_q = HFI1_NUM_VNIC_CTXT;
hfi_info.cap = HFI_VNIC_CAP_SG;
vdev = hfi_vnic_device_register(cdev, port_num, vport_num, vinfo,
diff --git a/drivers/infiniband/hw/hfi1/vnic_main.c b/drivers/infiniband/hw/hfi1/vnic_main.c
index 82e30bd..a21e4cd 100644
--- a/drivers/infiniband/hw/hfi1/vnic_main.c
+++ b/drivers/infiniband/hw/hfi1/vnic_main.c
@@ -294,15 +294,21 @@ int hfi1_vnic_put_skb(struct hfi_vnic_device *vdev,

u8 hfi1_vnic_select_queue(struct hfi_vnic_device *vdev, u8 vl, u8 entropy)
{
- return 0;
+ struct hfi1_devdata *dd = (struct hfi1_devdata *)vdev->cdev->hfi_priv;
+ struct sdma_engine *sde;
+
+ sde = sdma_select_engine_vl(dd, entropy, vl);
+ return sde->this_idx;
}

bool hfi1_vnic_get_write_avail(struct hfi_vnic_device *vdev, u8 q_idx)
{
+ struct hfi1_vnic_vport_info *vinfo = vdev->hfi_priv;
+
if (q_idx >= vdev->hfi_info.num_tx_q)
return false;

- return true;
+ return hfi1_vnic_sdma_write_avail(vinfo, q_idx);
}

void hfi1_vnic_bypass_rcv(struct hfi1_packet *packet)
@@ -504,6 +510,13 @@ int hfi1_vnic_init(struct hfi_vnic_device *vdev)
int i, rc = 0;

mutex_lock(&hfi1_mutex);
+
+ if (!dd->vnic.num_vports) {
+ rc = hfi1_vnic_txreq_init(dd);
+ if (rc)
+ goto txreq_fail;
+ }
+
for (i = dd->vnic.num_ctxt; i < vdev->hfi_info.num_rx_q; i++) {
rc = hfi1_vnic_allot_ctxt(dd, &dd->vnic.ctxt[i]);
if (rc)
@@ -531,7 +544,11 @@ int hfi1_vnic_init(struct hfi_vnic_device *vdev)

dd->vnic.num_vports++;
vinfo->vdev = vdev;
+ hfi1_vnic_sdma_init(vinfo);
alloc_fail:
+ if (!dd->vnic.num_vports)
+ hfi1_vnic_txreq_deinit(dd);
+txreq_fail:
mutex_unlock(&hfi1_mutex);
return rc;
}
@@ -549,6 +566,7 @@ void hfi1_vnic_deinit(struct hfi_vnic_device *vdev)
}
hfi1_deinit_vnic_rsm(dd);
dd->vnic.num_ctxt = 0;
+ hfi1_vnic_txreq_deinit(dd);
}

mutex_unlock(&hfi1_mutex);
diff --git a/drivers/infiniband/hw/hfi1/vnic_sdma.c b/drivers/infiniband/hw/hfi1/vnic_sdma.c
index 66abad0..e9754dd 100644
--- a/drivers/infiniband/hw/hfi1/vnic_sdma.c
+++ b/drivers/infiniband/hw/hfi1/vnic_sdma.c
@@ -52,9 +52,269 @@
#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
+#define HFI1_VNIC_SDMA_RETRY_COUNT 1
+
+/*
+ * 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
+ * @retry_count: tx retry count
+ */
+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;
+
+ u32 retry_count;
+};
+
+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 (ret)
+ goto bail_txadd;
+
+ for (i = 0; i < skb_shinfo(tx->skb)->nr_frags; i++) {
+ struct skb_frag_struct *frag = &skb_shinfo(tx->skb)->frags[i];
+
+ /* combine physically continuous fragments later? */
+ ret = sdma_txadd_page(sde->dd,
+ &tx->txreq,
+ skb_frag_page(frag),
+ frag->page_offset,
+ skb_frag_size(frag));
+ if (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 (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 (ret)
+ goto bail_txadd;
+
+ /* add the ulp payload */
+ ret = build_vnic_ulp_payload(sde, tx);
+bail_txadd:
+ return ret;
+}
+
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 (READ_ONCE(vnic_sdma->state) != HFI1_VNIC_SDMA_Q_ACTIVE)
+ goto tx_err;
+
+ if (!sde || !sdma_running(sde))
+ goto tx_err;
+
+ tx = kmem_cache_alloc(dd->vnic.txreq_cache, GFP_ATOMIC);
+ if (!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;
+ tx->retry_count = 0;
+
+ ret = sdma_send_txreq(sde, &vnic_sdma->wait, &tx->txreq);
+ /* When -ECOMM, sdma callback will be called with ABORT status */
+ if (ret && unlikely(ret != -ECOMM))
+ goto free_desc;
+
+ 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);
+ 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 *wait,
+ struct sdma_txreq *txreq,
+ unsigned int seq)
+{
+ struct hfi1_vnic_sdma *vnic_sdma =
+ container_of(wait, struct hfi1_vnic_sdma, wait);
+ struct hfi1_ibdev *dev = &vnic_sdma->dd->verbs_dev;
+ struct vnic_txreq *tx = container_of(txreq, struct vnic_txreq, txreq);
+
+ if (sdma_progress(sde, seq, txreq))
+ if (tx->retry_count++ < HFI1_VNIC_SDMA_RETRY_COUNT)
+ return -EAGAIN;
+
+ vnic_sdma->state = HFI1_VNIC_SDMA_Q_DEFERRED;
+ write_seqlock(&dev->iowait_lock);
+ if (list_empty(&vnic_sdma->wait.list))
+ list_add_tail(&vnic_sdma->wait.list, &sde->dmawait);
+ write_sequnlock(&dev->iowait_lock);
+ 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;
+ u8 evt = HFI_VNIC_EVT_TX0 + vnic_sdma->q_idx;
+ struct hfi1_vnic_notifier *notifier;
+
+ vnic_sdma->state = HFI1_VNIC_SDMA_Q_ACTIVE;
+ notifier = rcu_dereference(vinfo->notifier);
+ if (notifier && notifier->cb && test_bit(evt, vinfo->event_flags))
+ notifier->cb(vinfo->vdev, evt);
+};
+
+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->vdev->hfi_info.num_tx_q; i++) {
+ struct hfi1_vnic_sdma *vnic_sdma = &vinfo->sdma[i];
+
+ iowait_init(&vnic_sdma->wait, 0, NULL, hfi1_vnic_sdma_sleep,
+ hfi1_vnic_sdma_wakeup, 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) {
+ INIT_LIST_HEAD(&vnic_sdma->stx.list);
+ vnic_sdma->stx.num_desc = HFI1_VNIC_SDMA_DESC_WTRMRK;
+ list_add_tail(&vnic_sdma->stx.list,
+ &vnic_sdma->wait.tx_head);
+ }
+ }
+}
+
+static void hfi1_vnic_txreq_kmem_cache_ctor(void *obj)
+{
+ struct vnic_txreq *tx = (struct vnic_txreq *)obj;
+
+ memset(tx, 0, sizeof(*tx));
+}
+
+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,
+ hfi1_vnic_txreq_kmem_cache_ctor);
+ 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;
+}
--
1.8.3.1