[net-next PATCH v5 6/7] octeon_ep: add Tx/Rx processing and interrupt support

From: Veerasenareddy Burru
Date: Tue Apr 12 2022 - 23:36:13 EST

Add support to enable MSI-x and register interrupts.
Add support to process Tx and Rx traffic. Includes processing
Tx completions and Rx refill.

Signed-off-by: Veerasenareddy Burru <vburru@xxxxxxxxxxx>
Signed-off-by: Abhijit Ayarekar <aayarekar@xxxxxxxxxxx>
Signed-off-by: Satananda Burla <sburla@xxxxxxxxxxx>
---
V4 -> V5:
- Fix spelling mistake.

V3 -> V4: no change.

V2 -> V3: no change.

V1 -> V2:
- fix build errors observed with clang and "make W=1 C=1".

.../ethernet/marvell/octeon_ep/octep_main.c | 587 ++++++++++++++++++
.../net/ethernet/marvell/octeon_ep/octep_rx.c | 244 ++++++++
.../net/ethernet/marvell/octeon_ep/octep_tx.c | 73 +++
3 files changed, 904 insertions(+)

diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
index dac1e9464794..2f6579d7c945 100644
--- a/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
+++ b/drivers/net/ethernet/marvell/octeon_ep/octep_main.c
@@ -32,6 +32,431 @@ MODULE_DESCRIPTION(OCTEP_DRV_STRING);
MODULE_LICENSE("GPL");
MODULE_VERSION(OCTEP_DRV_VERSION_STR);

+/**
+ * octep_alloc_ioq_vectors() - Allocate Tx/Rx Queue interrupt info.
+ *
+ * @oct: Octeon device private data structure.
+ *
+ * Allocate resources to hold per Tx/Rx queue interrupt info.
+ * This is the information passed to interrupt handler, from which napi poll
+ * is scheduled and includes quick access to private data of Tx/Rx queue
+ * corresponding to the interrupt being handled.
+ *
+ * Return: 0, on successful allocation of resources for all queue interrupts.
+ * -1, if failed to allocate any resource.
+ */
+static int octep_alloc_ioq_vectors(struct octep_device *oct)
+{
+ int i;
+ struct octep_ioq_vector *ioq_vector;
+
+ for (i = 0; i < oct->num_oqs; i++) {
+ oct->ioq_vector[i] = vzalloc(sizeof(*oct->ioq_vector[i]));
+ if (!oct->ioq_vector[i])
+ goto free_ioq_vector;
+
+ ioq_vector = oct->ioq_vector[i];
+ ioq_vector->iq = oct->iq[i];
+ ioq_vector->oq = oct->oq[i];
+ ioq_vector->octep_dev = oct;
+ }
+
+ dev_info(&oct->pdev->dev, "Allocated %d IOQ vectors\n", oct->num_oqs);
+ return 0;
+
+free_ioq_vector:
+ while (i) {
+ i--;
+ vfree(oct->ioq_vector[i]);
+ oct->ioq_vector[i] = NULL;
+ }
+ return -1;
+}
+
+/**
+ * octep_free_ioq_vectors() - Free Tx/Rx Queue interrupt vector info.
+ *
+ * @oct: Octeon device private data structure.
+ */
+static void octep_free_ioq_vectors(struct octep_device *oct)
+{
+ int i;
+
+ for (i = 0; i < oct->num_oqs; i++) {
+ if (oct->ioq_vector[i]) {
+ vfree(oct->ioq_vector[i]);
+ oct->ioq_vector[i] = NULL;
+ }
+ }
+ netdev_info(oct->netdev, "Freed IOQ Vectors\n");
+}
+
+/**
+ * octep_enable_msix_range() - enable MSI-x interrupts.
+ *
+ * @oct: Octeon device private data structure.
+ *
+ * Allocate and enable all MSI-x interrupts (queue and non-queue interrupts)
+ * for the Octeon device.
+ *
+ * Return: 0, on successfully enabling all MSI-x interrupts.
+ * -1, if failed to enable any MSI-x interrupt.
+ */
+static int octep_enable_msix_range(struct octep_device *oct)
+{
+ int num_msix, msix_allocated;
+ int i;
+
+ /* Generic interrupts apart from input/output queues */
+ num_msix = oct->num_oqs + CFG_GET_NON_IOQ_MSIX(oct->conf);
+ oct->msix_entries = kcalloc(num_msix,
+ sizeof(struct msix_entry), GFP_KERNEL);
+ if (!oct->msix_entries)
+ goto msix_alloc_err;
+
+ for (i = 0; i < num_msix; i++)
+ oct->msix_entries[i].entry = i;
+
+ msix_allocated = pci_enable_msix_range(oct->pdev, oct->msix_entries,
+ num_msix, num_msix);
+ if (msix_allocated != num_msix) {
+ dev_err(&oct->pdev->dev,
+ "Failed to enable %d msix irqs; got only %d\n",
+ num_msix, msix_allocated);
+ goto enable_msix_err;
+ }
+ oct->num_irqs = msix_allocated;
+ dev_info(&oct->pdev->dev, "MSI-X enabled successfully\n");
+
+ return 0;
+
+enable_msix_err:
+ if (msix_allocated > 0)
+ pci_disable_msix(oct->pdev);
+ kfree(oct->msix_entries);
+ oct->msix_entries = NULL;
+msix_alloc_err:
+ return -1;
+}
+
+/**
+ * octep_disable_msix() - disable MSI-x interrupts.
+ *
+ * @oct: Octeon device private data structure.
+ *
+ * Disable MSI-x on the Octeon device.
+ */
+static void octep_disable_msix(struct octep_device *oct)
+{
+ pci_disable_msix(oct->pdev);
+ kfree(oct->msix_entries);
+ oct->msix_entries = NULL;
+ dev_info(&oct->pdev->dev, "Disabled MSI-X\n");
+}
+
+/**
+ * octep_non_ioq_intr_handler() - common handler for all generic interrupts.
+ *
+ * @irq: Interrupt number.
+ * @data: interrupt data.
+ *
+ * this is common handler for all non-queue (generic) interrupts.
+ */
+static irqreturn_t octep_non_ioq_intr_handler(int irq, void *data)
+{
+ struct octep_device *oct = data;
+
+ return oct->hw_ops.non_ioq_intr_handler(oct);
+}
+
+/**
+ * octep_ioq_intr_handler() - handler for all Tx/Rx queue interrupts.
+ *
+ * @irq: Interrupt number.
+ * @data: interrupt data contains pointers to Tx/Rx queue private data
+ * and correspong NAPI context.
+ *
+ * this is common handler for all non-queue (generic) interrupts.
+ */
+static irqreturn_t octep_ioq_intr_handler(int irq, void *data)
+{
+ struct octep_ioq_vector *ioq_vector = data;
+ struct octep_device *oct = ioq_vector->octep_dev;
+
+ return oct->hw_ops.ioq_intr_handler(ioq_vector);
+}
+
+/**
+ * octep_request_irqs() - Register interrupt handlers.
+ *
+ * @oct: Octeon device private data structure.
+ *
+ * Register handlers for all queue and non-queue interrupts.
+ *
+ * Return: 0, on successful registration of all interrupt handlers.
+ * -1, on any error.
+ */
+static int octep_request_irqs(struct octep_device *oct)
+{
+ struct net_device *netdev = oct->netdev;
+ struct octep_ioq_vector *ioq_vector;
+ struct msix_entry *msix_entry;
+ char **non_ioq_msix_names;
+ int num_non_ioq_msix;
+ int ret, i;
+
+ num_non_ioq_msix = CFG_GET_NON_IOQ_MSIX(oct->conf);
+ non_ioq_msix_names = CFG_GET_NON_IOQ_MSIX_NAMES(oct->conf);
+
+ oct->non_ioq_irq_names = kcalloc(num_non_ioq_msix,
+ OCTEP_MSIX_NAME_SIZE, GFP_KERNEL);
+ if (!oct->non_ioq_irq_names)
+ goto alloc_err;
+
+ /* First few MSI-X interrupts are non-queue interrupts */
+ for (i = 0; i < num_non_ioq_msix; i++) {
+ char *irq_name;
+
+ irq_name = &oct->non_ioq_irq_names[i * OCTEP_MSIX_NAME_SIZE];
+ msix_entry = &oct->msix_entries[i];
+
+ snprintf(irq_name, OCTEP_MSIX_NAME_SIZE,
+ "%s-%s", netdev->name, non_ioq_msix_names[i]);
+ ret = request_irq(msix_entry->vector,
+ octep_non_ioq_intr_handler, 0,
+ irq_name, oct);
+ if (ret) {
+ netdev_err(netdev,
+ "request_irq failed for %s; err=%d",
+ irq_name, ret);
+ goto non_ioq_irq_err;
+ }
+ }
+
+ /* Request IRQs for Tx/Rx queues */
+ for (i = 0; i < oct->num_oqs; i++) {
+ ioq_vector = oct->ioq_vector[i];
+ msix_entry = &oct->msix_entries[i + num_non_ioq_msix];
+
+ snprintf(ioq_vector->name, sizeof(ioq_vector->name),
+ "%s-q%d", netdev->name, i);
+ ret = request_irq(msix_entry->vector,
+ octep_ioq_intr_handler, 0,
+ ioq_vector->name, ioq_vector);
+ if (ret) {
+ netdev_err(netdev,
+ "request_irq failed for Q-%d; err=%d",
+ i, ret);
+ goto ioq_irq_err;
+ }
+
+ cpumask_set_cpu(i % num_online_cpus(),
+ &ioq_vector->affinity_mask);
+ irq_set_affinity_hint(msix_entry->vector,
+ &ioq_vector->affinity_mask);
+ }
+
+ return 0;
+ioq_irq_err:
+ while (i > num_non_ioq_msix) {
+ --i;
+ irq_set_affinity_hint(oct->msix_entries[i].vector, NULL);
+ free_irq(oct->msix_entries[i].vector, oct->ioq_vector[i]);
+ }
+non_ioq_irq_err:
+ while (i) {
+ --i;
+ free_irq(oct->msix_entries[i].vector, oct);
+ }
+alloc_err:
+ return -1;
+}
+
+/**
+ * octep_free_irqs() - free all registered interrupts.
+ *
+ * @oct: Octeon device private data structure.
+ *
+ * Free all queue and non-queue interrupts of the Octeon device.
+ */
+static void octep_free_irqs(struct octep_device *oct)
+{
+ int i;
+
+ /* First few MSI-X interrupts are non queue interrupts; free them */
+ for (i = 0; i < CFG_GET_NON_IOQ_MSIX(oct->conf); i++)
+ free_irq(oct->msix_entries[i].vector, oct);
+ kfree(oct->non_ioq_irq_names);
+
+ /* Free IRQs for Input/Output (Tx/Rx) queues */
+ for (i = CFG_GET_NON_IOQ_MSIX(oct->conf); i < oct->num_irqs; i++) {
+ irq_set_affinity_hint(oct->msix_entries[i].vector, NULL);
+ free_irq(oct->msix_entries[i].vector,
+ oct->ioq_vector[i - CFG_GET_NON_IOQ_MSIX(oct->conf)]);
+ }
+ netdev_info(oct->netdev, "IRQs freed\n");
+}
+
+/**
+ * octep_setup_irqs() - setup interrupts for the Octeon device.
+ *
+ * @oct: Octeon device private data structure.
+ *
+ * Allocate data structures to hold per interrupt information, allocate/enable
+ * MSI-x interrupt and register interrupt handlers.
+ *
+ * Return: 0, on successful allocation and registration of all interrupts.
+ * -1, on any error.
+ */
+static int octep_setup_irqs(struct octep_device *oct)
+{
+ if (octep_alloc_ioq_vectors(oct))
+ goto ioq_vector_err;
+
+ if (octep_enable_msix_range(oct))
+ goto enable_msix_err;
+
+ if (octep_request_irqs(oct))
+ goto request_irq_err;
+
+ return 0;
+
+request_irq_err:
+ octep_disable_msix(oct);
+enable_msix_err:
+ octep_free_ioq_vectors(oct);
+ioq_vector_err:
+ return -1;
+}
+
+/**
+ * octep_clean_irqs() - free all interrupts and its resources.
+ *
+ * @oct: Octeon device private data structure.
+ */
+static void octep_clean_irqs(struct octep_device *oct)
+{
+ octep_free_irqs(oct);
+ octep_disable_msix(oct);
+ octep_free_ioq_vectors(oct);
+}
+
+/**
+ * octep_enable_ioq_irq() - Enable MSI-x interrupt of a Tx/Rx queue.
+ *
+ * @iq: Octeon Tx queue data structure.
+ * @oq: Octeon Rx queue data structure.
+ */
+static void octep_enable_ioq_irq(struct octep_iq *iq, struct octep_oq *oq)
+{
+ u32 pkts_pend = oq->pkts_pending;
+
+ netdev_dbg(iq->netdev, "enabling intr for Q-%u\n", iq->q_no);
+ if (iq->pkts_processed) {
+ writel(iq->pkts_processed, iq->inst_cnt_reg);
+ iq->pkt_in_done -= iq->pkts_processed;
+ iq->pkts_processed = 0;
+ }
+ if (oq->last_pkt_count - pkts_pend) {
+ writel(oq->last_pkt_count - pkts_pend, oq->pkts_sent_reg);
+ oq->last_pkt_count = pkts_pend;
+ }
+
+ /* Flush the previous wrties before writing to RESEND bit */
+ wmb();
+ writeq(1UL << OCTEP_OQ_INTR_RESEND_BIT, oq->pkts_sent_reg);
+ writeq(1UL << OCTEP_IQ_INTR_RESEND_BIT, iq->inst_cnt_reg);
+}
+
+/**
+ * octep_napi_poll() - NAPI poll function for Tx/Rx.
+ *
+ * @napi: pointer to napi context.
+ * @budget: max number of packets to be processed in single invocation.
+ */
+static int octep_napi_poll(struct napi_struct *napi, int budget)
+{
+ struct octep_ioq_vector *ioq_vector =
+ container_of(napi, struct octep_ioq_vector, napi);
+ u32 tx_pending, rx_done;
+
+ tx_pending = octep_iq_process_completions(ioq_vector->iq, budget);
+ rx_done = octep_oq_process_rx(ioq_vector->oq, budget);
+
+ /* need more polling if tx completion processing is still pending or
+ * processed at least 'budget' number of rx packets.
+ */
+ if (tx_pending || rx_done >= budget)
+ return budget;
+
+ napi_complete(napi);
+ octep_enable_ioq_irq(ioq_vector->iq, ioq_vector->oq);
+ return rx_done;
+}
+
+/**
+ * octep_napi_add() - Add NAPI poll for all Tx/Rx queues.
+ *
+ * @oct: Octeon device private data structure.
+ */
+static void octep_napi_add(struct octep_device *oct)
+{
+ int i;
+
+ for (i = 0; i < oct->num_oqs; i++) {
+ netdev_dbg(oct->netdev, "Adding NAPI on Q-%d\n", i);
+ netif_napi_add(oct->netdev, &oct->ioq_vector[i]->napi,
+ octep_napi_poll, 64);
+ oct->oq[i]->napi = &oct->ioq_vector[i]->napi;
+ }
+}
+
+/**
+ * octep_napi_delete() - delete NAPI poll callback for all Tx/Rx queues.
+ *
+ * @oct: Octeon device private data structure.
+ */
+static void octep_napi_delete(struct octep_device *oct)
+{
+ int i;
+
+ for (i = 0; i < oct->num_oqs; i++) {
+ netdev_dbg(oct->netdev, "Deleting NAPI on Q-%d\n", i);
+ netif_napi_del(&oct->ioq_vector[i]->napi);
+ oct->oq[i]->napi = NULL;
+ }
+}
+
+/**
+ * octep_napi_enable() - enable NAPI for all Tx/Rx queues.
+ *
+ * @oct: Octeon device private data structure.
+ */
+static void octep_napi_enable(struct octep_device *oct)
+{
+ int i;
+
+ for (i = 0; i < oct->num_oqs; i++) {
+ netdev_dbg(oct->netdev, "Enabling NAPI on Q-%d\n", i);
+ napi_enable(&oct->ioq_vector[i]->napi);
+ }
+}
+
+/**
+ * octep_napi_disable() - disable NAPI for all Tx/Rx queues.
+ *
+ * @oct: Octeon device private data structure.
+ */
+static void octep_napi_disable(struct octep_device *oct)
+{
+ int i;
+
+ for (i = 0; i < oct->num_oqs; i++) {
+ netdev_dbg(oct->netdev, "Disabling NAPI on Q-%d\n", i);
+ napi_disable(&oct->ioq_vector[i]->napi);
+ }
+}
+
static void octep_link_up(struct net_device *netdev)
{
netif_carrier_on(netdev);
@@ -63,6 +488,8 @@ static int octep_open(struct net_device *netdev)
goto setup_iq_err;
if (octep_setup_oqs(oct))
goto setup_oq_err;
+ if (octep_setup_irqs(oct))
+ goto setup_irq_err;

err = netif_set_real_num_tx_queues(netdev, oct->num_oqs);
if (err)
@@ -71,6 +498,9 @@ static int octep_open(struct net_device *netdev)
if (err)
goto set_queues_err;

+ octep_napi_add(oct);
+ octep_napi_enable(oct);
+
oct->link_info.admin_up = 1;
octep_set_rx_state(oct, true);

@@ -93,6 +523,10 @@ static int octep_open(struct net_device *netdev)
return 0;

set_queues_err:
+ octep_napi_disable(oct);
+ octep_napi_delete(oct);
+ octep_clean_irqs(oct);
+setup_irq_err:
octep_free_oqs(oct);
setup_oq_err:
octep_free_iqs(oct);
@@ -126,7 +560,10 @@ static int octep_stop(struct net_device *netdev)
oct->link_info.oper_up = 0;

oct->hw_ops.disable_interrupts(oct);
+ octep_napi_disable(oct);
+ octep_napi_delete(oct);

+ octep_clean_irqs(oct);
octep_clean_iqs(oct);

oct->hw_ops.disable_io_queues(oct);
@@ -137,6 +574,36 @@ static int octep_stop(struct net_device *netdev)
return 0;
}

+/**
+ * octep_iq_full_check() - check if a Tx queue is full.
+ *
+ * @iq: Octeon Tx queue data structure.
+ *
+ * Return: 0, if the Tx queue is not full.
+ * 1, if the Tx queue is full.
+ */
+static inline int octep_iq_full_check(struct octep_iq *iq)
+{
+ if (likely((iq->max_count - atomic_read(&iq->instr_pending)) >=
+ OCTEP_WAKE_QUEUE_THRESHOLD))
+ return 0;
+
+ /* Stop the queue if unable to send */
+ netif_stop_subqueue(iq->netdev, iq->q_no);
+
+ /* check again and restart the queue, in case NAPI has just freed
+ * enough Tx ring entries.
+ */
+ if (unlikely((iq->max_count - atomic_read(&iq->instr_pending)) >=
+ OCTEP_WAKE_QUEUE_THRESHOLD)) {
+ netif_start_subqueue(iq->netdev, iq->q_no);
+ iq->stats.restart_cnt++;
+ return 0;
+ }
+
+ return 1;
+}
+
/**
* octep_start_xmit() - Enqueue packet to Octoen hardware Tx Queue.
*
@@ -149,6 +616,126 @@ static int octep_stop(struct net_device *netdev)
static netdev_tx_t octep_start_xmit(struct sk_buff *skb,
struct net_device *netdev)
{
+ struct octep_device *oct = netdev_priv(netdev);
+ struct octep_tx_sglist_desc *sglist;
+ struct octep_tx_buffer *tx_buffer;
+ struct octep_tx_desc_hw *hw_desc;
+ struct skb_shared_info *shinfo;
+ struct octep_instr_hdr *ih;
+ struct octep_iq *iq;
+ skb_frag_t *frag;
+ u16 nr_frags, si;
+ u16 q_no, wi;
+
+ q_no = skb_get_queue_mapping(skb);
+ if (q_no >= oct->num_iqs) {
+ netdev_err(netdev, "Invalid Tx skb->queue_mapping=%d\n", q_no);
+ q_no = q_no % oct->num_iqs;
+ }
+
+ iq = oct->iq[q_no];
+ if (octep_iq_full_check(iq)) {
+ iq->stats.tx_busy++;
+ return NETDEV_TX_BUSY;
+ }
+
+ shinfo = skb_shinfo(skb);
+ nr_frags = shinfo->nr_frags;
+
+ wi = iq->host_write_index;
+ hw_desc = &iq->desc_ring[wi];
+ hw_desc->ih64 = 0;
+
+ tx_buffer = iq->buff_info + wi;
+ tx_buffer->skb = skb;
+
+ ih = &hw_desc->ih;
+ ih->tlen = skb->len;
+ ih->pkind = oct->pkind;
+
+ if (!nr_frags) {
+ tx_buffer->gather = 0;
+ tx_buffer->dma = dma_map_single(iq->dev, skb->data,
+ skb->len, DMA_TO_DEVICE);
+ if (dma_mapping_error(iq->dev, tx_buffer->dma))
+ goto dma_map_err;
+ hw_desc->dptr = tx_buffer->dma;
+ } else {
+ /* Scatter/Gather */
+ dma_addr_t dma;
+ u16 len;
+
+ sglist = tx_buffer->sglist;
+
+ ih->gsz = nr_frags + 1;
+ ih->gather = 1;
+ tx_buffer->gather = 1;
+
+ len = skb_headlen(skb);
+ dma = dma_map_single(iq->dev, skb->data, len, DMA_TO_DEVICE);
+ if (dma_mapping_error(iq->dev, dma))
+ goto dma_map_err;
+
+ dma_sync_single_for_cpu(iq->dev, tx_buffer->sglist_dma,
+ OCTEP_SGLIST_SIZE_PER_PKT,
+ DMA_TO_DEVICE);
+ memset(sglist, 0, OCTEP_SGLIST_SIZE_PER_PKT);
+ sglist[0].len[3] = len;
+ sglist[0].dma_ptr[0] = dma;
+
+ si = 1; /* entry 0 is main skb, mapped above */
+ frag = &shinfo->frags[0];
+ while (nr_frags--) {
+ len = skb_frag_size(frag);
+ dma = skb_frag_dma_map(iq->dev, frag, 0,
+ len, DMA_TO_DEVICE);
+ if (dma_mapping_error(iq->dev, dma))
+ goto dma_map_sg_err;
+
+ sglist[si >> 2].len[3 - (si & 3)] = len;
+ sglist[si >> 2].dma_ptr[si & 3] = dma;
+
+ frag++;
+ si++;
+ }
+ dma_sync_single_for_device(iq->dev, tx_buffer->sglist_dma,
+ OCTEP_SGLIST_SIZE_PER_PKT,
+ DMA_TO_DEVICE);
+
+ hw_desc->dptr = tx_buffer->sglist_dma;
+ }
+
+ /* Flush the hw descriptor before writing to doorbell */
+ wmb();
+
+ /* Ring Doorbell to notify the NIC there is a new packet */
+ writel(1, iq->doorbell_reg);
+ atomic_inc(&iq->instr_pending);
+ wi++;
+ if (wi == iq->max_count)
+ wi = 0;
+ iq->host_write_index = wi;
+
+ netdev_tx_sent_queue(iq->netdev_q, skb->len);
+ iq->stats.instr_posted++;
+ skb_tx_timestamp(skb);
+ return NETDEV_TX_OK;
+
+dma_map_sg_err:
+ if (si > 0) {
+ dma_unmap_single(iq->dev, sglist[0].dma_ptr[0],
+ sglist[0].len[0], DMA_TO_DEVICE);
+ sglist[0].len[0] = 0;
+ }
+ while (si > 1) {
+ dma_unmap_page(iq->dev, sglist[si >> 2].dma_ptr[si & 3],
+ sglist[si >> 2].len[si & 3], DMA_TO_DEVICE);
+ sglist[si >> 2].len[si & 3] = 0;
+ si--;
+ }
+ tx_buffer->gather = 0;
+dma_map_err:
+ dev_kfree_skb_any(skb);
return NETDEV_TX_OK;
}

diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
index 7086ede58475..945947ec7723 100644
--- a/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
+++ b/drivers/net/ethernet/marvell/octeon_ep/octep_rx.c
@@ -68,6 +68,50 @@ static int octep_oq_fill_ring_buffers(struct octep_oq *oq)
return -1;
}

+/**
+ * octep_oq_refill() - refill buffers for used Rx ring descriptors.
+ *
+ * @oct: Octeon device private data structure.
+ * @oq: Octeon Rx queue data structure.
+ *
+ * Return: number of descriptors successfully refilled with receive buffers.
+ */
+static int octep_oq_refill(struct octep_device *oct, struct octep_oq *oq)
+{
+ struct octep_oq_desc_hw *desc_ring = oq->desc_ring;
+ struct page *page;
+ u32 refill_idx, i;
+
+ refill_idx = oq->host_refill_idx;
+ for (i = 0; i < oq->refill_count; i++) {
+ page = dev_alloc_page();
+ if (unlikely(!page)) {
+ dev_err(oq->dev, "refill: rx buffer alloc failed\n");
+ oq->stats.alloc_failures++;
+ break;
+ }
+
+ desc_ring[refill_idx].buffer_ptr = dma_map_page(oq->dev, page, 0,
+ PAGE_SIZE, DMA_FROM_DEVICE);
+ if (dma_mapping_error(oq->dev, desc_ring[refill_idx].buffer_ptr)) {
+ dev_err(oq->dev,
+ "OQ-%d buffer refill: DMA mapping error!\n",
+ oq->q_no);
+ put_page(page);
+ oq->stats.alloc_failures++;
+ break;
+ }
+ oq->buff_info[refill_idx].page = page;
+ refill_idx++;
+ if (refill_idx == oq->max_count)
+ refill_idx = 0;
+ }
+ oq->host_refill_idx = refill_idx;
+ oq->refill_count -= i;
+
+ return i;
+}
+
/**
* octep_setup_oq() - Setup a Rx queue.
*
@@ -262,3 +306,203 @@ void octep_free_oqs(struct octep_device *oct)
"Successfully freed OQ(RxQ)-%d.\n", i);
}
}
+
+/**
+ * octep_oq_check_hw_for_pkts() - Check for new Rx packets.
+ *
+ * @oct: Octeon device private data structure.
+ * @oq: Octeon Rx queue data structure.
+ *
+ * Return: packets received after previous check.
+ */
+static int octep_oq_check_hw_for_pkts(struct octep_device *oct,
+ struct octep_oq *oq)
+{
+ u32 pkt_count, new_pkts;
+
+ pkt_count = readl(oq->pkts_sent_reg);
+ new_pkts = pkt_count - oq->last_pkt_count;
+
+ /* Clear the hardware packets counter register if the rx queue is
+ * being processed continuously with-in a single interrupt and
+ * reached half its max value.
+ * this counter is not cleared every time read, to save write cycles.
+ */
+ if (unlikely(pkt_count > 0xF0000000U)) {
+ writel(pkt_count, oq->pkts_sent_reg);
+ pkt_count = readl(oq->pkts_sent_reg);
+ new_pkts += pkt_count;
+ }
+ oq->last_pkt_count = pkt_count;
+ oq->pkts_pending += new_pkts;
+ return new_pkts;
+}
+
+/**
+ * __octep_oq_process_rx() - Process hardware Rx queue and push to stack.
+ *
+ * @oct: Octeon device private data structure.
+ * @oq: Octeon Rx queue data structure.
+ * @pkts_to_process: number of packets to be processed.
+ *
+ * Process the new packets in Rx queue.
+ * Packets larger than single Rx buffer arrive in consecutive descriptors.
+ * But, count returned by the API only accounts full packets, not fragments.
+ *
+ * Return: number of packets processed and pushed to stack.
+ */
+static int __octep_oq_process_rx(struct octep_device *oct,
+ struct octep_oq *oq, u16 pkts_to_process)
+{
+ struct octep_oq_resp_hw_ext *resp_hw_ext = NULL;
+ struct octep_rx_buffer *buff_info;
+ struct octep_oq_resp_hw *resp_hw;
+ u32 pkt, rx_bytes, desc_used;
+ struct sk_buff *skb;
+ u16 data_offset;
+ u32 read_idx;
+
+ read_idx = oq->host_read_idx;
+ rx_bytes = 0;
+ desc_used = 0;
+ for (pkt = 0; pkt < pkts_to_process; pkt++) {
+ buff_info = (struct octep_rx_buffer *)&oq->buff_info[read_idx];
+ dma_unmap_page(oq->dev, oq->desc_ring[read_idx].buffer_ptr,
+ PAGE_SIZE, DMA_FROM_DEVICE);
+ resp_hw = page_address(buff_info->page);
+ buff_info->page = NULL;
+
+ /* Swap the length field that is in Big-Endian to CPU */
+ buff_info->len = be64_to_cpu(resp_hw->length);
+ if (oct->caps_enabled & OCTEP_CAP_RX_CHECKSUM) {
+ /* Extended response header is immediately after
+ * response header (resp_hw)
+ */
+ resp_hw_ext = (struct octep_oq_resp_hw_ext *)
+ (resp_hw + 1);
+ buff_info->len -= OCTEP_OQ_RESP_HW_EXT_SIZE;
+ /* Packet Data is immediately after
+ * extended response header.
+ */
+ data_offset = OCTEP_OQ_RESP_HW_SIZE +
+ OCTEP_OQ_RESP_HW_EXT_SIZE;
+ } else {
+ /* Data is immediately after
+ * Hardware Rx response header.
+ */
+ data_offset = OCTEP_OQ_RESP_HW_SIZE;
+ }
+ rx_bytes += buff_info->len;
+
+ if (buff_info->len <= oq->max_single_buffer_size) {
+ skb = build_skb((void *)resp_hw, PAGE_SIZE);
+ skb_reserve(skb, data_offset);
+ skb_put(skb, buff_info->len);
+ read_idx++;
+ desc_used++;
+ if (read_idx == oq->max_count)
+ read_idx = 0;
+ } else {
+ struct skb_shared_info *shinfo;
+ u16 data_len;
+
+ skb = build_skb((void *)resp_hw, PAGE_SIZE);
+ skb_reserve(skb, data_offset);
+ /* Head fragment includes response header(s);
+ * subsequent fragments contains only data.
+ */
+ skb_put(skb, oq->max_single_buffer_size);
+ read_idx++;
+ desc_used++;
+ if (read_idx == oq->max_count)
+ read_idx = 0;
+
+ shinfo = skb_shinfo(skb);
+ data_len = buff_info->len - oq->max_single_buffer_size;
+ while (data_len) {
+ dma_unmap_page(oq->dev, oq->desc_ring[read_idx].buffer_ptr,
+ PAGE_SIZE, DMA_FROM_DEVICE);
+ buff_info = (struct octep_rx_buffer *)
+ &oq->buff_info[read_idx];
+ if (data_len < oq->buffer_size) {
+ buff_info->len = data_len;
+ data_len = 0;
+ } else {
+ buff_info->len = oq->buffer_size;
+ data_len -= oq->buffer_size;
+ }
+
+ skb_add_rx_frag(skb, shinfo->nr_frags,
+ buff_info->page, 0,
+ buff_info->len,
+ buff_info->len);
+ buff_info->page = NULL;
+ read_idx++;
+ desc_used++;
+ if (read_idx == oq->max_count)
+ read_idx = 0;
+ }
+ }
+
+ skb->dev = oq->netdev;
+ skb->protocol = eth_type_trans(skb, skb->dev);
+ if (resp_hw_ext &&
+ resp_hw_ext->csum_verified == OCTEP_CSUM_VERIFIED)
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ else
+ skb->ip_summed = CHECKSUM_NONE;
+ napi_gro_receive(oq->napi, skb);
+ }
+
+ oq->host_read_idx = read_idx;
+ oq->refill_count += desc_used;
+ oq->stats.packets += pkt;
+ oq->stats.bytes += rx_bytes;
+
+ return pkt;
+}
+
+/**
+ * octep_oq_process_rx() - Process Rx queue.
+ *
+ * @oq: Octeon Rx queue data structure.
+ * @budget: max number of packets can be processed in one invocation.
+ *
+ * Check for newly received packets and process them.
+ * Keeps checking for new packets until budget is used or no new packets seen.
+ *
+ * Return: number of packets processed.
+ */
+int octep_oq_process_rx(struct octep_oq *oq, int budget)
+{
+ u32 pkts_available, pkts_processed, total_pkts_processed;
+ struct octep_device *oct = oq->octep_dev;
+
+ pkts_available = 0;
+ pkts_processed = 0;
+ total_pkts_processed = 0;
+ while (total_pkts_processed < budget) {
+ /* update pending count only when current one exhausted */
+ if (oq->pkts_pending == 0)
+ octep_oq_check_hw_for_pkts(oct, oq);
+ pkts_available = min(budget - total_pkts_processed,
+ oq->pkts_pending);
+ if (!pkts_available)
+ break;
+
+ pkts_processed = __octep_oq_process_rx(oct, oq,
+ pkts_available);
+ oq->pkts_pending -= pkts_processed;
+ total_pkts_processed += pkts_processed;
+ }
+
+ if (oq->refill_count >= oq->refill_threshold) {
+ u32 desc_refilled = octep_oq_refill(oct, oq);
+
+ /* flush pending writes before updating credits */
+ wmb();
+ writel(desc_refilled, oq->pkts_credit_reg);
+ }
+
+ return total_pkts_processed;
+}
diff --git a/drivers/net/ethernet/marvell/octeon_ep/octep_tx.c b/drivers/net/ethernet/marvell/octeon_ep/octep_tx.c
index 185522d72475..511552bc3e87 100644
--- a/drivers/net/ethernet/marvell/octeon_ep/octep_tx.c
+++ b/drivers/net/ethernet/marvell/octeon_ep/octep_tx.c
@@ -24,6 +24,79 @@ static void octep_iq_reset_indices(struct octep_iq *iq)
atomic_set(&iq->instr_pending, 0);
}

+/**
+ * octep_iq_process_completions() - Process Tx queue completions.
+ *
+ * @iq: Octeon Tx queue data structure.
+ * @budget: max number of completions to be processed in one invocation.
+ */
+int octep_iq_process_completions(struct octep_iq *iq, u16 budget)
+{
+ u32 compl_pkts, compl_bytes, compl_sg;
+ struct octep_device *oct = iq->octep_dev;
+ struct octep_tx_buffer *tx_buffer;
+ struct skb_shared_info *shinfo;
+ u32 fi = iq->flush_index;
+ struct sk_buff *skb;
+ u8 frags, i;
+
+ compl_pkts = 0;
+ compl_sg = 0;
+ compl_bytes = 0;
+ iq->octep_read_index = oct->hw_ops.update_iq_read_idx(iq);
+
+ while (likely(budget && (fi != iq->octep_read_index))) {
+ tx_buffer = iq->buff_info + fi;
+ skb = tx_buffer->skb;
+
+ fi++;
+ if (unlikely(fi == iq->max_count))
+ fi = 0;
+ compl_bytes += skb->len;
+ compl_pkts++;
+ budget--;
+
+ if (!tx_buffer->gather) {
+ dma_unmap_single(iq->dev, tx_buffer->dma,
+ tx_buffer->skb->len, DMA_TO_DEVICE);
+ dev_kfree_skb_any(skb);
+ continue;
+ }
+
+ /* Scatter/Gather */
+ shinfo = skb_shinfo(skb);
+ frags = shinfo->nr_frags;
+ compl_sg++;
+
+ dma_unmap_single(iq->dev, tx_buffer->sglist[0].dma_ptr[0],
+ tx_buffer->sglist[0].len[0], DMA_TO_DEVICE);
+
+ i = 1; /* entry 0 is main skb, unmapped above */
+ while (frags--) {
+ dma_unmap_page(iq->dev, tx_buffer->sglist[i >> 2].dma_ptr[i & 3],
+ tx_buffer->sglist[i >> 2].len[i & 3], DMA_TO_DEVICE);
+ i++;
+ }
+
+ dev_kfree_skb_any(skb);
+ }
+
+ iq->pkts_processed += compl_pkts;
+ atomic_sub(compl_pkts, &iq->instr_pending);
+ iq->stats.instr_completed += compl_pkts;
+ iq->stats.bytes_sent += compl_bytes;
+ iq->stats.sgentry_sent += compl_sg;
+ iq->flush_index = fi;
+
+ netdev_tx_completed_queue(iq->netdev_q, compl_pkts, compl_bytes);
+
+ if (unlikely(__netif_subqueue_stopped(iq->netdev, iq->q_no)) &&
+ ((iq->max_count - atomic_read(&iq->instr_pending)) >
+ OCTEP_WAKE_QUEUE_THRESHOLD))
+ netif_wake_subqueue(iq->netdev, iq->q_no);
+ return !budget;
+}
+
/**
* octep_iq_free_pending() - Free Tx buffers for pending completions.
*
--
2.17.1