Imported Upstream version 17.05

Change-Id: Id1e419c5a214e4a18739663b91f0f9a549f1fdc6
Signed-off-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>

1 files changed, 560 insertions, 0 deletions

diff --git a/drivers/net/sfc/sfc_ef10_tx.c b/drivers/net/sfc/sfc_ef10_tx.c
new file mode 100644
index 00000000..bac9baa9
--- /dev/null
+++ b/drivers/net/sfc/sfc_ef10_tx.c
@@ -0,0 +1,560 @@
+/*-
+ *   BSD LICENSE
+ *
+ * Copyright (c) 2016 Solarflare Communications Inc.
+ * All rights reserved.
+ *
+ * This software was jointly developed between OKTET Labs (under contract
+ * for Solarflare) and Solarflare Communications, Inc.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright notice,
+ *    this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright notice,
+ *    this list of conditions and the following disclaimer in the documentation
+ *    and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
+ * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+ * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
+ * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE,
+ * EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+#include <stdbool.h>
+
+#include <rte_mbuf.h>
+#include <rte_io.h>
+
+#include "efx.h"
+#include "efx_types.h"
+#include "efx_regs.h"
+#include "efx_regs_ef10.h"
+
+#include "sfc_dp_tx.h"
+#include "sfc_tweak.h"
+#include "sfc_kvargs.h"
+#include "sfc_ef10.h"
+
+#define sfc_ef10_tx_err(dpq, ...) \
+	SFC_DP_LOG(SFC_KVARG_DATAPATH_EF10, ERR, dpq, __VA_ARGS__)
+
+/** Maximum length of the DMA descriptor data */
+#define SFC_EF10_TX_DMA_DESC_LEN_MAX \
+	((1u << ESF_DZ_TX_KER_BYTE_CNT_WIDTH) - 1)
+
+/**
+ * Maximum number of descriptors/buffers in the Tx ring.
+ * It should guarantee that corresponding event queue never overfill.
+ * EF10 native datapath uses event queue of the same size as Tx queue.
+ * Maximum number of events on datapath can be estimated as number of
+ * Tx queue entries (one event per Tx buffer in the worst case) plus
+ * Tx error and flush events.
+ */
+#define SFC_EF10_TXQ_LIMIT(_ndesc) \
+	((_ndesc) - 1 /* head must not step on tail */ - \
+	 (SFC_EF10_EV_PER_CACHE_LINE - 1) /* max unused EvQ entries */ - \
+	 1 /* Rx error */ - 1 /* flush */)
+
+struct sfc_ef10_tx_sw_desc {
+	struct rte_mbuf			*mbuf;
+};
+
+struct sfc_ef10_txq {
+	unsigned int			flags;
+#define SFC_EF10_TXQ_STARTED		0x1
+#define SFC_EF10_TXQ_NOT_RUNNING	0x2
+#define SFC_EF10_TXQ_EXCEPTION		0x4
+
+	unsigned int			ptr_mask;
+	unsigned int			added;
+	unsigned int			completed;
+	unsigned int			free_thresh;
+	unsigned int			evq_read_ptr;
+	struct sfc_ef10_tx_sw_desc	*sw_ring;
+	efx_qword_t			*txq_hw_ring;
+	volatile void			*doorbell;
+	efx_qword_t			*evq_hw_ring;
+
+	/* Datapath transmit queue anchor */
+	struct sfc_dp_txq		dp;
+};
+
+static inline struct sfc_ef10_txq *
+sfc_ef10_txq_by_dp_txq(struct sfc_dp_txq *dp_txq)
+{
+	return container_of(dp_txq, struct sfc_ef10_txq, dp);
+}
+
+static bool
+sfc_ef10_tx_get_event(struct sfc_ef10_txq *txq, efx_qword_t *tx_ev)
+{
+	volatile efx_qword_t *evq_hw_ring = txq->evq_hw_ring;
+
+	/*
+	 * Exception flag is set when reap is done.
+	 * It is never done twice per packet burst get and absence of
+	 * the flag is checked on burst get entry.
+	 */
+	SFC_ASSERT((txq->flags & SFC_EF10_TXQ_EXCEPTION) == 0);
+
+	*tx_ev = evq_hw_ring[txq->evq_read_ptr & txq->ptr_mask];
+
+	if (!sfc_ef10_ev_present(*tx_ev))
+		return false;
+
+	if (unlikely(EFX_QWORD_FIELD(*tx_ev, FSF_AZ_EV_CODE) !=
+		     FSE_AZ_EV_CODE_TX_EV)) {
+		/*
+		 * Do not move read_ptr to keep the event for exception
+		 * handling by the control path.
+		 */
+		txq->flags |= SFC_EF10_TXQ_EXCEPTION;
+		sfc_ef10_tx_err(&txq->dp.dpq,
+				"TxQ exception at EvQ read ptr %#x",
+				txq->evq_read_ptr);
+		return false;
+	}
+
+	txq->evq_read_ptr++;
+	return true;
+}
+
+static void
+sfc_ef10_tx_reap(struct sfc_ef10_txq *txq)
+{
+	const unsigned int old_read_ptr = txq->evq_read_ptr;
+	const unsigned int ptr_mask = txq->ptr_mask;
+	unsigned int completed = txq->completed;
+	unsigned int pending = completed;
+	const unsigned int curr_done = pending - 1;
+	unsigned int anew_done = curr_done;
+	efx_qword_t tx_ev;
+
+	while (sfc_ef10_tx_get_event(txq, &tx_ev)) {
+		/*
+		 * DROP_EVENT is an internal to the NIC, software should
+		 * never see it and, therefore, may ignore it.
+		 */
+
+		/* Update the latest done descriptor */
+		anew_done = EFX_QWORD_FIELD(tx_ev, ESF_DZ_TX_DESCR_INDX);
+	}
+	pending += (anew_done - curr_done) & ptr_mask;
+
+	if (pending != completed) {
+		do {
+			struct sfc_ef10_tx_sw_desc *txd;
+
+			txd = &txq->sw_ring[completed & ptr_mask];
+
+			if (txd->mbuf != NULL) {
+				rte_pktmbuf_free(txd->mbuf);
+				txd->mbuf = NULL;
+			}
+		} while (++completed != pending);
+
+		txq->completed = completed;
+	}
+
+	sfc_ef10_ev_qclear(txq->evq_hw_ring, ptr_mask, old_read_ptr,
+			   txq->evq_read_ptr);
+}
+
+static void
+sfc_ef10_tx_qdesc_dma_create(phys_addr_t addr, uint16_t size, bool eop,
+			     efx_qword_t *edp)
+{
+	EFX_POPULATE_QWORD_4(*edp,
+			     ESF_DZ_TX_KER_TYPE, 0,
+			     ESF_DZ_TX_KER_CONT, !eop,
+			     ESF_DZ_TX_KER_BYTE_CNT, size,
+			     ESF_DZ_TX_KER_BUF_ADDR, addr);
+}
+
+static inline void
+sfc_ef10_tx_qpush(struct sfc_ef10_txq *txq, unsigned int added,
+		  unsigned int pushed)
+{
+	efx_qword_t desc;
+	efx_oword_t oword;
+
+	/*
+	 * This improves performance by pushing a TX descriptor at the same
+	 * time as the doorbell. The descriptor must be added to the TXQ,
+	 * so that can be used if the hardware decides not to use the pushed
+	 * descriptor.
+	 */
+	desc.eq_u64[0] = txq->txq_hw_ring[pushed & txq->ptr_mask].eq_u64[0];
+	EFX_POPULATE_OWORD_3(oword,
+		ERF_DZ_TX_DESC_WPTR, added & txq->ptr_mask,
+		ERF_DZ_TX_DESC_HWORD, EFX_QWORD_FIELD(desc, EFX_DWORD_1),
+		ERF_DZ_TX_DESC_LWORD, EFX_QWORD_FIELD(desc, EFX_DWORD_0));
+
+	/* DMA sync to device is not required */
+
+	/*
+	 * rte_io_wmb() which guarantees that the STORE operations
+	 * (i.e. Tx and event descriptor updates) that precede
+	 * the rte_io_wmb() call are visible to NIC before the STORE
+	 * operations that follow it (i.e. doorbell write).
+	 */
+	rte_io_wmb();
+
+	*(volatile __m128i *)txq->doorbell = oword.eo_u128[0];
+}
+
+static unsigned int
+sfc_ef10_tx_pkt_descs_max(const struct rte_mbuf *m)
+{
+	unsigned int extra_descs_per_seg;
+	unsigned int extra_descs_per_pkt;
+
+	/*
+	 * VLAN offload is not supported yet, so no extra descriptors
+	 * are required for VLAN option descriptor.
+	 */
+
+/** Maximum length of the mbuf segment data */
+#define SFC_MBUF_SEG_LEN_MAX		UINT16_MAX
+	RTE_BUILD_BUG_ON(sizeof(m->data_len) != 2);
+
+	/*
+	 * Each segment is already counted once below.  So, calculate
+	 * how many extra DMA descriptors may be required per segment in
+	 * the worst case because of maximum DMA descriptor length limit.
+	 * If maximum segment length is less or equal to maximum DMA
+	 * descriptor length, no extra DMA descriptors are required.
+	 */
+	extra_descs_per_seg =
+		(SFC_MBUF_SEG_LEN_MAX - 1) / SFC_EF10_TX_DMA_DESC_LEN_MAX;
+
+/** Maximum length of the packet */
+#define SFC_MBUF_PKT_LEN_MAX		UINT32_MAX
+	RTE_BUILD_BUG_ON(sizeof(m->pkt_len) != 4);
+
+	/*
+	 * One more limitation on maximum number of extra DMA descriptors
+	 * comes from slicing entire packet because of DMA descriptor length
+	 * limit taking into account that there is at least one segment
+	 * which is already counted below (so division of the maximum
+	 * packet length minus one with round down).
+	 * TSO is not supported yet, so packet length is limited by
+	 * maximum PDU size.
+	 */
+	extra_descs_per_pkt =
+		(RTE_MIN((unsigned int)EFX_MAC_PDU_MAX,
+			 SFC_MBUF_PKT_LEN_MAX) - 1) /
+		SFC_EF10_TX_DMA_DESC_LEN_MAX;
+
+	return m->nb_segs + RTE_MIN(m->nb_segs * extra_descs_per_seg,
+				    extra_descs_per_pkt);
+}
+
+static uint16_t
+sfc_ef10_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts, uint16_t nb_pkts)
+{
+	struct sfc_ef10_txq * const txq = sfc_ef10_txq_by_dp_txq(tx_queue);
+	unsigned int ptr_mask;
+	unsigned int added;
+	unsigned int dma_desc_space;
+	bool reap_done;
+	struct rte_mbuf **pktp;
+	struct rte_mbuf **pktp_end;
+
+	if (unlikely(txq->flags &
+		     (SFC_EF10_TXQ_NOT_RUNNING | SFC_EF10_TXQ_EXCEPTION)))
+		return 0;
+
+	ptr_mask = txq->ptr_mask;
+	added = txq->added;
+	dma_desc_space = SFC_EF10_TXQ_LIMIT(ptr_mask + 1) -
+			 (added - txq->completed);
+
+	reap_done = (dma_desc_space < txq->free_thresh);
+	if (reap_done) {
+		sfc_ef10_tx_reap(txq);
+		dma_desc_space = SFC_EF10_TXQ_LIMIT(ptr_mask + 1) -
+				 (added - txq->completed);
+	}
+
+	for (pktp = &tx_pkts[0], pktp_end = &tx_pkts[nb_pkts];
+	     pktp != pktp_end;
+	     ++pktp) {
+		struct rte_mbuf *m_seg = *pktp;
+		unsigned int pkt_start = added;
+		uint32_t pkt_len;
+
+		if (likely(pktp + 1 != pktp_end))
+			rte_mbuf_prefetch_part1(pktp[1]);
+
+		if (sfc_ef10_tx_pkt_descs_max(m_seg) > dma_desc_space) {
+			if (reap_done)
+				break;
+
+			/* Push already prepared descriptors before polling */
+			if (added != txq->added) {
+				sfc_ef10_tx_qpush(txq, added, txq->added);
+				txq->added = added;
+			}
+
+			sfc_ef10_tx_reap(txq);
+			reap_done = true;
+			dma_desc_space = SFC_EF10_TXQ_LIMIT(ptr_mask + 1) -
+				(added - txq->completed);
+			if (sfc_ef10_tx_pkt_descs_max(m_seg) > dma_desc_space)
+				break;
+		}
+
+		pkt_len = m_seg->pkt_len;
+		do {
+			phys_addr_t seg_addr = rte_mbuf_data_dma_addr(m_seg);
+			unsigned int seg_len = rte_pktmbuf_data_len(m_seg);
+
+			SFC_ASSERT(seg_len <= SFC_EF10_TX_DMA_DESC_LEN_MAX);
+
+			pkt_len -= seg_len;
+
+			sfc_ef10_tx_qdesc_dma_create(seg_addr,
+				seg_len, (pkt_len == 0),
+				&txq->txq_hw_ring[added & ptr_mask]);
+			++added;
+
+		} while ((m_seg = m_seg->next) != 0);
+
+		dma_desc_space -= (added - pkt_start);
+
+		/* Assign mbuf to the last used desc */
+		txq->sw_ring[(added - 1) & ptr_mask].mbuf = *pktp;
+	}
+
+	if (likely(added != txq->added)) {
+		sfc_ef10_tx_qpush(txq, added, txq->added);
+		txq->added = added;
+	}
+
+#if SFC_TX_XMIT_PKTS_REAP_AT_LEAST_ONCE
+	if (!reap_done)
+		sfc_ef10_tx_reap(txq);
+#endif
+
+	return pktp - &tx_pkts[0];
+}
+
+static uint16_t
+sfc_ef10_simple_xmit_pkts(void *tx_queue, struct rte_mbuf **tx_pkts,
+			  uint16_t nb_pkts)
+{
+	struct sfc_ef10_txq * const txq = sfc_ef10_txq_by_dp_txq(tx_queue);
+	unsigned int ptr_mask;
+	unsigned int added;
+	unsigned int dma_desc_space;
+	bool reap_done;
+	struct rte_mbuf **pktp;
+	struct rte_mbuf **pktp_end;
+
+	if (unlikely(txq->flags &
+		     (SFC_EF10_TXQ_NOT_RUNNING | SFC_EF10_TXQ_EXCEPTION)))
+		return 0;
+
+	ptr_mask = txq->ptr_mask;
+	added = txq->added;
+	dma_desc_space = SFC_EF10_TXQ_LIMIT(ptr_mask + 1) -
+			 (added - txq->completed);
+
+	reap_done = (dma_desc_space < RTE_MAX(txq->free_thresh, nb_pkts));
+	if (reap_done) {
+		sfc_ef10_tx_reap(txq);
+		dma_desc_space = SFC_EF10_TXQ_LIMIT(ptr_mask + 1) -
+				 (added - txq->completed);
+	}
+
+	pktp_end = &tx_pkts[MIN(nb_pkts, dma_desc_space)];
+	for (pktp = &tx_pkts[0]; pktp != pktp_end; ++pktp) {
+		struct rte_mbuf *pkt = *pktp;
+		unsigned int id = added & ptr_mask;
+
+		SFC_ASSERT(rte_pktmbuf_data_len(pkt) <=
+			   SFC_EF10_TX_DMA_DESC_LEN_MAX);
+
+		sfc_ef10_tx_qdesc_dma_create(rte_mbuf_data_dma_addr(pkt),
+					     rte_pktmbuf_data_len(pkt),
+					     true, &txq->txq_hw_ring[id]);
+
+		txq->sw_ring[id].mbuf = pkt;
+
+		++added;
+	}
+
+	if (likely(added != txq->added)) {
+		sfc_ef10_tx_qpush(txq, added, txq->added);
+		txq->added = added;
+	}
+
+#if SFC_TX_XMIT_PKTS_REAP_AT_LEAST_ONCE
+	if (!reap_done)
+		sfc_ef10_tx_reap(txq);
+#endif
+
+	return pktp - &tx_pkts[0];
+}
+
+
+static sfc_dp_tx_qcreate_t sfc_ef10_tx_qcreate;
+static int
+sfc_ef10_tx_qcreate(uint16_t port_id, uint16_t queue_id,
+		    const struct rte_pci_addr *pci_addr, int socket_id,
+		    const struct sfc_dp_tx_qcreate_info *info,
+		    struct sfc_dp_txq **dp_txqp)
+{
+	struct sfc_ef10_txq *txq;
+	int rc;
+
+	rc = EINVAL;
+	if (info->txq_entries != info->evq_entries)
+		goto fail_bad_args;
+
+	rc = ENOMEM;
+	txq = rte_zmalloc_socket("sfc-ef10-txq", sizeof(*txq),
+				 RTE_CACHE_LINE_SIZE, socket_id);
+	if (txq == NULL)
+		goto fail_txq_alloc;
+
+	sfc_dp_queue_init(&txq->dp.dpq, port_id, queue_id, pci_addr);
+
+	rc = ENOMEM;
+	txq->sw_ring = rte_calloc_socket("sfc-ef10-txq-sw_ring",
+					 info->txq_entries,
+					 sizeof(*txq->sw_ring),
+					 RTE_CACHE_LINE_SIZE, socket_id);
+	if (txq->sw_ring == NULL)
+		goto fail_sw_ring_alloc;
+
+	txq->flags = SFC_EF10_TXQ_NOT_RUNNING;
+	txq->ptr_mask = info->txq_entries - 1;
+	txq->free_thresh = info->free_thresh;
+	txq->txq_hw_ring = info->txq_hw_ring;
+	txq->doorbell = (volatile uint8_t *)info->mem_bar +
+			ER_DZ_TX_DESC_UPD_REG_OFST +
+			info->hw_index * ER_DZ_TX_DESC_UPD_REG_STEP;
+	txq->evq_hw_ring = info->evq_hw_ring;
+
+	*dp_txqp = &txq->dp;
+	return 0;
+
+fail_sw_ring_alloc:
+	rte_free(txq);
+
+fail_txq_alloc:
+fail_bad_args:
+	return rc;
+}
+
+static sfc_dp_tx_qdestroy_t sfc_ef10_tx_qdestroy;
+static void
+sfc_ef10_tx_qdestroy(struct sfc_dp_txq *dp_txq)
+{
+	struct sfc_ef10_txq *txq = sfc_ef10_txq_by_dp_txq(dp_txq);
+
+	rte_free(txq->sw_ring);
+	rte_free(txq);
+}
+
+static sfc_dp_tx_qstart_t sfc_ef10_tx_qstart;
+static int
+sfc_ef10_tx_qstart(struct sfc_dp_txq *dp_txq, unsigned int evq_read_ptr,
+		   unsigned int txq_desc_index)
+{
+	struct sfc_ef10_txq *txq = sfc_ef10_txq_by_dp_txq(dp_txq);
+
+	txq->evq_read_ptr = evq_read_ptr;
+	txq->added = txq->completed = txq_desc_index;
+
+	txq->flags |= SFC_EF10_TXQ_STARTED;
+	txq->flags &= ~(SFC_EF10_TXQ_NOT_RUNNING | SFC_EF10_TXQ_EXCEPTION);
+
+	return 0;
+}
+
+static sfc_dp_tx_qstop_t sfc_ef10_tx_qstop;
+static void
+sfc_ef10_tx_qstop(struct sfc_dp_txq *dp_txq, unsigned int *evq_read_ptr)
+{
+	struct sfc_ef10_txq *txq = sfc_ef10_txq_by_dp_txq(dp_txq);
+
+	txq->flags |= SFC_EF10_TXQ_NOT_RUNNING;
+
+	*evq_read_ptr = txq->evq_read_ptr;
+}
+
+static sfc_dp_tx_qtx_ev_t sfc_ef10_tx_qtx_ev;
+static bool
+sfc_ef10_tx_qtx_ev(struct sfc_dp_txq *dp_txq, __rte_unused unsigned int id)
+{
+	__rte_unused struct sfc_ef10_txq *txq = sfc_ef10_txq_by_dp_txq(dp_txq);
+
+	SFC_ASSERT(txq->flags & SFC_EF10_TXQ_NOT_RUNNING);
+
+	/*
+	 * It is safe to ignore Tx event since we reap all mbufs on
+	 * queue purge anyway.
+	 */
+
+	return false;
+}
+
+static sfc_dp_tx_qreap_t sfc_ef10_tx_qreap;
+static void
+sfc_ef10_tx_qreap(struct sfc_dp_txq *dp_txq)
+{
+	struct sfc_ef10_txq *txq = sfc_ef10_txq_by_dp_txq(dp_txq);
+	unsigned int txds;
+
+	for (txds = 0; txds <= txq->ptr_mask; ++txds) {
+		if (txq->sw_ring[txds].mbuf != NULL) {
+			rte_pktmbuf_free(txq->sw_ring[txds].mbuf);
+			txq->sw_ring[txds].mbuf = NULL;
+		}
+	}
+
+	txq->flags &= ~SFC_EF10_TXQ_STARTED;
+}
+
+struct sfc_dp_tx sfc_ef10_tx = {
+	.dp = {
+		.name		= SFC_KVARG_DATAPATH_EF10,
+		.type		= SFC_DP_TX,
+		.hw_fw_caps	= SFC_DP_HW_FW_CAP_EF10,
+	},
+	.features		= SFC_DP_TX_FEAT_MULTI_SEG,
+	.qcreate		= sfc_ef10_tx_qcreate,
+	.qdestroy		= sfc_ef10_tx_qdestroy,
+	.qstart			= sfc_ef10_tx_qstart,
+	.qtx_ev			= sfc_ef10_tx_qtx_ev,
+	.qstop			= sfc_ef10_tx_qstop,
+	.qreap			= sfc_ef10_tx_qreap,
+	.pkt_burst		= sfc_ef10_xmit_pkts,
+};
+
+struct sfc_dp_tx sfc_ef10_simple_tx = {
+	.dp = {
+		.name		= SFC_KVARG_DATAPATH_EF10_SIMPLE,
+		.type		= SFC_DP_TX,
+	},
+	.features		= 0,
+	.qcreate		= sfc_ef10_tx_qcreate,
+	.qdestroy		= sfc_ef10_tx_qdestroy,
+	.qstart			= sfc_ef10_tx_qstart,
+	.qtx_ev			= sfc_ef10_tx_qtx_ev,
+	.qstop			= sfc_ef10_tx_qstop,
+	.qreap			= sfc_ef10_tx_qreap,
+	.pkt_burst		= sfc_ef10_simple_xmit_pkts,
+};