2006-12-20 12:43:19

by Divy Le Ray

Subject: [PATCH 5/10] cxgb3 - scatter gather engine

From: Divy Le Ray <[email protected]>

This path implements the scatter gather engine for the
Chelsio T3 network adapter's driver.

Signed-off-by: Divy Le Ray <[email protected]>
---

drivers/net/cxgb3/sge.c | 2702 ++++++++++++++++++++++++++++++++++++++++++
drivers/net/cxgb3/sge_defs.h | 251 ++++
2 files changed, 2953 insertions(+), 0 deletions(-)

diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c
new file mode 100755
index 0000000..6c77f4b
--- /dev/null
+++ b/drivers/net/cxgb3/sge.c
@@ -0,0 +1,2702 @@
+/*
+ * This file is part of the Chelsio T3 Ethernet driver.
+ *
+ * Copyright (C) 2005-2006 Chelsio Communications. All rights reserved.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the LICENSE file included in this
+ * release for licensing terms and conditions.
+ */
+
+#include <linux/skbuff.h>
+#include <linux/netdevice.h>
+#include <linux/etherdevice.h>
+#include <linux/if_vlan.h>
+#include <linux/ip.h>
+#include <linux/tcp.h>
+#include <linux/dma-mapping.h>
+#include "common.h"
+#include "regs.h"
+#include "sge_defs.h"
+#include "t3_cpl.h"
+#include "firmware_exports.h"
+
+#define USE_GTS 0
+
+#define SGE_RX_SM_BUF_SIZE 1536
+#define SGE_RX_COPY_THRES 256
+
+# define SGE_RX_DROP_THRES 16
+
+/*
+ * Period of the Tx buffer reclaim timer. This timer does not need to run
+ * frequently as Tx buffers are usually reclaimed by new Tx packets.
+ */
+#define TX_RECLAIM_PERIOD (HZ / 4)
+
+/* WR size in bytes */
+#define WR_LEN (WR_FLITS * 8)
+
+/*
+ * Types of Tx queues in each queue set. Order here matters, do not change.
+ */
+enum { TXQ_ETH, TXQ_OFLD, TXQ_CTRL };
+
+/* Values for sge_txq.flags */
+enum {
+ TXQ_RUNNING = 1 << 0, /* fetch engine is running */
+ TXQ_LAST_PKT_DB = 1 << 1, /* last packet rang the doorbell */
+};
+
+struct tx_desc {
+ u64 flit[TX_DESC_FLITS];
+};
+
+struct rx_desc {
+ __be32 addr_lo;
+ __be32 len_gen;
+ __be32 gen2;
+ __be32 addr_hi;
+};
+
+struct tx_sw_desc { /* SW state per Tx descriptor */
+ struct sk_buff *skb;
+};
+
+struct rx_sw_desc { /* SW state per Rx descriptor */
+ struct sk_buff *skb;
+ DECLARE_PCI_UNMAP_ADDR(dma_addr);
+};
+
+struct rsp_desc { /* response queue descriptor */
+ struct rss_header rss_hdr;
+ __be32 flags;
+ __be32 len_cq;
+ u8 imm_data[47];
+ u8 intr_gen;
+};
+
+struct unmap_info { /* packet unmapping info, overlays skb->cb */
+ int sflit; /* start flit of first SGL entry in Tx descriptor */
+ u16 fragidx; /* first page fragment in current Tx descriptor */
+ u16 addr_idx; /* buffer index of first SGL entry in descriptor */
+ u32 len; /* mapped length of skb main body */
+};
+
+/*
+ * Maps a number of flits to the number of Tx descriptors that can hold them.
+ * The formula is
+ *
+ * desc = 1 + (flits - 2) / (WR_FLITS - 1).
+ *
+ * HW allows up to 4 descriptors to be combined into a WR.
+ */
+static u8 flit_desc_map[] = {
+ 0,
+#if SGE_NUM_GENBITS == 1
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+ 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4
+#elif SGE_NUM_GENBITS == 2
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+ 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4, 4,
+#else
+# error "SGE_NUM_GENBITS must be 1 or 2"
+#endif
+};
+
+static inline struct sge_qset *fl_to_qset(const struct sge_fl *q, int qidx)
+{
+ return container_of(q, struct sge_qset, fl[qidx]);
+}
+
+static inline struct sge_qset *rspq_to_qset(const struct sge_rspq *q)
+{
+ return container_of(q, struct sge_qset, rspq);
+}
+
+static inline struct sge_qset *txq_to_qset(const struct sge_txq *q, int qidx)
+{
+ return container_of(q, struct sge_qset, txq[qidx]);
+}
+
+/**
+ * refill_rspq - replenish an SGE response queue
+ * @adapter: the adapter
+ * @q: the response queue to replenish
+ * @credits: how many new responses to make available
+ *
+ * Replenishes a response queue by making the supplied number of responses
+ * available to HW.
+ */
+static inline void refill_rspq(struct adapter *adapter,
+ const struct sge_rspq *q, unsigned int credits)
+{
+ t3_write_reg(adapter, A_SG_RSPQ_CREDIT_RETURN,
+ V_RSPQ(q->cntxt_id) | V_CREDITS(credits));
+}
+
+/**
+ * need_skb_unmap - does the platform need unmapping of sk_buffs?
+ *
+ * Returns true if the platfrom needs sk_buff unmapping. The compiler
+ * optimizes away unecessary code if this returns true.
+ */
+static inline int need_skb_unmap(void)
+{
+ /*
+ * This structure is used to tell if the platfrom needs buffer
+ * unmapping by checking if DECLARE_PCI_UNMAP_ADDR defines anything.
+ */
+ struct dummy {
+ DECLARE_PCI_UNMAP_ADDR(addr);
+ };
+
+ return sizeof(struct dummy) != 0;
+}
+
+/**
+ * unmap_skb - unmap a packet main body and its page fragments
+ * @skb: the packet
+ * @q: the Tx queue containing Tx descriptors for the packet
+ * @cidx: index of Tx descriptor
+ * @pdev: the PCI device
+ *
+ * Unmap the main body of an sk_buff and its page fragments, if any.
+ * Because of the fairly complicated structure of our SGLs and the desire
+ * to conserve space for metadata, we keep the information necessary to
+ * unmap an sk_buff partly in the sk_buff itself (in its cb), and partly
+ * in the Tx descriptors (the physical addresses of the various data
+ * buffers). The send functions initialize the state in skb->cb so we
+ * can unmap the buffers held in the first Tx descriptor here, and we
+ * have enough information at this point to update the state for the next
+ * Tx descriptor.
+ */
+static inline void unmap_skb(struct sk_buff *skb, struct sge_txq *q,
+ unsigned int cidx, struct pci_dev *pdev)
+{
+ const struct sg_ent *sgp;
+ struct unmap_info *ui = (struct unmap_info *)skb->cb;
+ int nfrags, frag_idx, curflit, j = ui->addr_idx;
+
+ sgp = (struct sg_ent *)&q->desc[cidx].flit[ui->sflit];
+
+ if (ui->len) {
+ pci_unmap_single(pdev, be64_to_cpu(sgp->addr[0]), ui->len,
+ PCI_DMA_TODEVICE);
+ ui->len = 0; /* so we know for next descriptor for this skb */
+ j = 1;
+ }
+
+ frag_idx = ui->fragidx;
+ curflit = ui->sflit + 1 + j;
+ nfrags = skb_shinfo(skb)->nr_frags;
+
+ while (frag_idx < nfrags && curflit < WR_FLITS) {
+ pci_unmap_page(pdev, be64_to_cpu(sgp->addr[j]),
+ skb_shinfo(skb)->frags[frag_idx].size,
+ PCI_DMA_TODEVICE);
+ j ^= 1;
+ if (j == 0) {
+ sgp++;
+ curflit++;
+ }
+ curflit++;
+ frag_idx++;
+ }
+
+ if (frag_idx < nfrags) { /* SGL continues into next Tx descriptor */
+ ui->fragidx = frag_idx;
+ ui->addr_idx = j;
+ ui->sflit = curflit - WR_FLITS - j; /* sflit can be -1 */
+ }
+}
+
+/**
+ * free_tx_desc - reclaims Tx descriptors and their buffers
+ * @adapter: the adapter
+ * @q: the Tx queue to reclaim descriptors from
+ * @n: the number of descriptors to reclaim
+ *
+ * Reclaims Tx descriptors from an SGE Tx queue and frees the associated
+ * Tx buffers. Called with the Tx queue lock held.
+ */
+static void free_tx_desc(struct adapter *adapter, struct sge_txq *q,
+ unsigned int n)
+{
+ struct tx_sw_desc *d;
+ struct pci_dev *pdev = adapter->pdev;
+ unsigned int cidx = q->cidx;
+
+ d = &q->sdesc[cidx];
+ while (n--) {
+ if (d->skb) { /* an SGL is present */
+ if (need_skb_unmap())
+ unmap_skb(d->skb, q, cidx, pdev);
+ if (d->skb->priority == cidx)
+ kfree_skb(d->skb);
+ }
+ ++d;
+ if (++cidx == q->size) {
+ cidx = 0;
+ d = q->sdesc;
+ }
+ }
+ q->cidx = cidx;
+}
+
+/**
+ * reclaim_completed_tx - reclaims completed Tx descriptors
+ * @adapter: the adapter
+ * @q: the Tx queue to reclaim completed descriptors from
+ *
+ * Reclaims Tx descriptors that the SGE has indicated it has processed,
+ * and frees the associated buffers if possible. Called with the Tx
+ * queue's lock held.
+ */
+static inline void reclaim_completed_tx(struct adapter *adapter,
+ struct sge_txq *q)
+{
+ unsigned int reclaim = q->processed - q->cleaned;
+
+ if (reclaim) {
+ free_tx_desc(adapter, q, reclaim);
+ q->cleaned += reclaim;
+ q->in_use -= reclaim;
+ }
+}
+
+/**
+ * should_restart_tx - are there enough resources to restart a Tx queue?
+ * @q: the Tx queue
+ *
+ * Checks if there are enough descriptors to restart a suspended Tx queue.
+ */
+static inline int should_restart_tx(const struct sge_txq *q)
+{
+ unsigned int r = q->processed - q->cleaned;
+
+ return q->in_use - r < (q->size >> 1);
+}
+
+/**
+ * free_rx_bufs - free the Rx buffers on an SGE free list
+ * @pdev: the PCI device associated with the adapter
+ * @rxq: the SGE free list to clean up
+ *
+ * Release the buffers on an SGE free-buffer Rx queue. HW fetching from
+ * this queue should be stopped before calling this function.
+ */
+static void free_rx_bufs(struct pci_dev *pdev, struct sge_fl *q)
+{
+ unsigned int cidx = q->cidx;
+
+ while (q->credits--) {
+ struct rx_sw_desc *d = &q->sdesc[cidx];
+
+ pci_unmap_single(pdev, pci_unmap_addr(d, dma_addr),
+ q->buf_size, PCI_DMA_FROMDEVICE);
+ kfree_skb(d->skb);
+ d->skb = NULL;
+ if (++cidx == q->size)
+ cidx = 0;
+ }
+}
+
+/**
+ * add_one_rx_buf - add a packet buffer to a free-buffer list
+ * @skb: the buffer to add
+ * @len: the buffer length
+ * @d: the HW Rx descriptor to write
+ * @sd: the SW Rx descriptor to write
+ * @gen: the generation bit value
+ * @pdev: the PCI device associated with the adapter
+ *
+ * Add a buffer of the given length to the supplied HW and SW Rx
+ * descriptors.
+ */
+static inline void add_one_rx_buf(struct sk_buff *skb, unsigned int len,
+ struct rx_desc *d, struct rx_sw_desc *sd,
+ unsigned int gen, struct pci_dev *pdev)
+{
+ dma_addr_t mapping;
+
+ sd->skb = skb;
+ mapping = pci_map_single(pdev, skb->data, len, PCI_DMA_FROMDEVICE);
+ pci_unmap_addr_set(sd, dma_addr, mapping);
+
+ d->addr_lo = cpu_to_be32(mapping);
+ d->addr_hi = cpu_to_be32((u64) mapping >> 32);
+ wmb();
+ d->len_gen = cpu_to_be32(V_FLD_GEN1(gen));
+ d->gen2 = cpu_to_be32(V_FLD_GEN2(gen));
+}
+
+/**
+ * refill_fl - refill an SGE free-buffer list
+ * @adapter: the adapter
+ * @q: the free-list to refill
+ * @n: the number of new buffers to allocate
+ * @gfp: the gfp flags for allocating new buffers
+ *
+ * (Re)populate an SGE free-buffer list with up to @n new packet buffers,
+ * allocated with the supplied gfp flags. The caller must assure that
+ * @n does not exceed the queue's capacity.
+ */
+static void refill_fl(struct adapter *adap, struct sge_fl *q, int n, gfp_t gfp)
+{
+ struct rx_sw_desc *sd = &q->sdesc[q->pidx];
+ struct rx_desc *d = &q->desc[q->pidx];
+
+ while (n--) {
+ struct sk_buff *skb = alloc_skb(q->buf_size, gfp);
+
+ if (!skb)
+ break;
+
+ add_one_rx_buf(skb, q->buf_size, d, sd, q->gen, adap->pdev);
+ d++;
+ sd++;
+ if (++q->pidx == q->size) {
+ q->pidx = 0;
+ q->gen ^= 1;
+ sd = q->sdesc;
+ d = q->desc;
+ }
+ q->credits++;
+ }
+
+ t3_write_reg(adap, A_SG_KDOORBELL, V_EGRCNTX(q->cntxt_id));
+}
+
+static inline void __refill_fl(struct adapter *adap, struct sge_fl *fl)
+{
+ refill_fl(adap, fl, min(16U, fl->size - fl->credits), GFP_ATOMIC);
+}
+
+/**
+ * recycle_rx_buf - recycle a receive buffer
+ * @adapter: the adapter
+ * @q: the SGE free list
+ * @idx: index of buffer to recycle
+ *
+ * Recycles the specified buffer on the given free list by adding it at
+ * the next available slot on the list.
+ */
+static void recycle_rx_buf(struct adapter *adap, struct sge_fl *q,
+ unsigned int idx)
+{
+ struct rx_desc *from = &q->desc[idx];
+ struct rx_desc *to = &q->desc[q->pidx];
+
+ q->sdesc[q->pidx] = q->sdesc[idx];
+ to->addr_lo = from->addr_lo; /* already big endian */
+ to->addr_hi = from->addr_hi; /* likewise */
+ wmb();
+ to->len_gen = cpu_to_be32(V_FLD_GEN1(q->gen));
+ to->gen2 = cpu_to_be32(V_FLD_GEN2(q->gen));
+ q->credits++;
+
+ if (++q->pidx == q->size) {
+ q->pidx = 0;
+ q->gen ^= 1;
+ }
+ t3_write_reg(adap, A_SG_KDOORBELL, V_EGRCNTX(q->cntxt_id));
+}
+
+/**
+ * alloc_ring - allocate resources for an SGE descriptor ring
+ * @pdev: the PCI device
+ * @nelem: the number of descriptors
+ * @elem_size: the size of each descriptor
+ * @sw_size: the size of the SW state associated with each ring element
+ * @phys: the physical address of the allocated ring
+ * @metadata: address of the array holding the SW state for the ring
+ *
+ * Allocates resources for an SGE descriptor ring, such as Tx queues,
+ * free buffer lists, or response queues. Each SGE ring requires
+ * space for its HW descriptors plus, optionally, space for the SW state
+ * associated with each HW entry (the metadata). The function returns
+ * three values: the virtual address for the HW ring (the return value
+ * of the function), the physical address of the HW ring, and the address
+ * of the SW ring.
+ */
+static void *alloc_ring(struct pci_dev *pdev, size_t nelem, size_t elem_size,
+ size_t sw_size, dma_addr_t *phys, void *metadata)
+{
+ size_t len = nelem * elem_size;
+ void *s = NULL;
+ void *p = dma_alloc_coherent(&pdev->dev, len, phys, GFP_KERNEL);
+
+ if (!p)
+ return NULL;
+ if (sw_size) {
+ s = kcalloc(nelem, sw_size, GFP_KERNEL);
+
+ if (!s) {
+ dma_free_coherent(&pdev->dev, len, p, *phys);
+ return NULL;
+ }
+ }
+ if (metadata)
+ *(void **)metadata = s;
+ memset(p, 0, len);
+ return p;
+}
+
+/**
+ * free_qset - free the resources of an SGE queue set
+ * @adapter: the adapter owning the queue set
+ * @q: the queue set
+ *
+ * Release the HW and SW resources associated with an SGE queue set, such
+ * as HW contexts, packet buffers, and descriptor rings. Traffic to the
+ * queue set must be quiesced prior to calling this.
+ */
+void t3_free_qset(struct adapter *adapter, struct sge_qset *q)
+{
+ int i;
+ struct pci_dev *pdev = adapter->pdev;
+
+ if (q->tx_reclaim_timer.function)
+ del_timer_sync(&q->tx_reclaim_timer);
+
+ for (i = 0; i < SGE_RXQ_PER_SET; ++i)
+ if (q->fl[i].desc) {
+ spin_lock(&adapter->sge.reg_lock);
+ t3_sge_disable_fl(adapter, q->fl[i].cntxt_id);
+ spin_unlock(&adapter->sge.reg_lock);
+ free_rx_bufs(pdev, &q->fl[i]);
+ kfree(q->fl[i].sdesc);
+ dma_free_coherent(&pdev->dev,
+ q->fl[i].size *
+ sizeof(struct rx_desc), q->fl[i].desc,
+ q->fl[i].phys_addr);
+ }
+
+ for (i = 0; i < SGE_TXQ_PER_SET; ++i)
+ if (q->txq[i].desc) {
+ spin_lock(&adapter->sge.reg_lock);
+ t3_sge_enable_ecntxt(adapter, q->txq[i].cntxt_id, 0);
+ spin_unlock(&adapter->sge.reg_lock);
+ if (q->txq[i].sdesc) {
+ free_tx_desc(adapter, &q->txq[i],
+ q->txq[i].in_use);
+ kfree(q->txq[i].sdesc);
+ }
+ dma_free_coherent(&pdev->dev,
+ q->txq[i].size *
+ sizeof(struct tx_desc),
+ q->txq[i].desc, q->txq[i].phys_addr);
+ __skb_queue_purge(&q->txq[i].sendq);
+ }
+
+ if (q->rspq.desc) {
+ spin_lock(&adapter->sge.reg_lock);
+ t3_sge_disable_rspcntxt(adapter, q->rspq.cntxt_id);
+ spin_unlock(&adapter->sge.reg_lock);
+ dma_free_coherent(&pdev->dev,
+ q->rspq.size * sizeof(struct rsp_desc),
+ q->rspq.desc, q->rspq.phys_addr);
+ }
+
+ if (q->netdev)
+ q->netdev->atalk_ptr = NULL;
+
+ memset(q, 0, sizeof(*q));
+}
+
+/**
+ * init_qset_cntxt - initialize an SGE queue set context info
+ * @qs: the queue set
+ * @id: the queue set id
+ *
+ * Initializes the TIDs and context ids for the queues of a queue set.
+ */
+static void init_qset_cntxt(struct sge_qset *qs, unsigned int id)
+{
+ qs->rspq.cntxt_id = id;
+ qs->fl[0].cntxt_id = 2 * id;
+ qs->fl[1].cntxt_id = 2 * id + 1;
+ qs->txq[TXQ_ETH].cntxt_id = FW_TUNNEL_SGEEC_START + id;
+ qs->txq[TXQ_ETH].token = FW_TUNNEL_TID_START + id;
+ qs->txq[TXQ_OFLD].cntxt_id = FW_OFLD_SGEEC_START + id;
+ qs->txq[TXQ_CTRL].cntxt_id = FW_CTRL_SGEEC_START + id;
+ qs->txq[TXQ_CTRL].token = FW_CTRL_TID_START + id;
+}
+
+/**
+ * sgl_len - calculates the size of an SGL of the given capacity
+ * @n: the number of SGL entries
+ *
+ * Calculates the number of flits needed for a scatter/gather list that
+ * can hold the given number of entries.
+ */
+static inline unsigned int sgl_len(unsigned int n)
+{
+ /* alternatively: 3 * (n / 2) + 2 * (n & 1) */
+ return (3 * n) / 2 + (n & 1);
+}
+
+/**
+ * flits_to_desc - returns the num of Tx descriptors for the given flits
+ * @n: the number of flits
+ *
+ * Calculates the number of Tx descriptors needed for the supplied number
+ * of flits.
+ */
+static inline unsigned int flits_to_desc(unsigned int n)
+{
+ BUG_ON(n >= ARRAY_SIZE(flit_desc_map));
+ return flit_desc_map[n];
+}
+
+/**
+ * get_packet - return the next ingress packet buffer from a free list
+ * @adap: the adapter that received the packet
+ * @fl: the SGE free list holding the packet
+ * @len: the packet length including any SGE padding
+ * @drop_thres: # of remaining buffers before we start dropping packets
+ *
+ * Get the next packet from a free list and complete setup of the
+ * sk_buff. If the packet is small we make a copy and recycle the
+ * original buffer, otherwise we use the original buffer itself. If a
+ * positive drop threshold is supplied packets are dropped and their
+ * buffers recycled if (a) the number of remaining buffers is under the
+ * threshold and the packet is too big to copy, or (b) the packet should
+ * be copied but there is no memory for the copy.
+ */
+static struct sk_buff *get_packet(struct adapter *adap, struct sge_fl *fl,
+ unsigned int len, unsigned int drop_thres)
+{
+ struct sk_buff *skb = NULL;
+ struct rx_sw_desc *sd = &fl->sdesc[fl->cidx];
+
+ prefetch(sd->skb->data);
+
+ if (len <= SGE_RX_COPY_THRES) {
+ skb = alloc_skb(len, GFP_ATOMIC);
+ if (likely(skb != NULL)) {
+ __skb_put(skb, len);
+ pci_dma_sync_single_for_cpu(adap->pdev,
+ pci_unmap_addr(sd,
+ dma_addr),
+ len, PCI_DMA_FROMDEVICE);
+ memcpy(skb->data, sd->skb->data, len);
+ pci_dma_sync_single_for_device(adap->pdev,
+ pci_unmap_addr(sd,
+ dma_addr),
+ len, PCI_DMA_FROMDEVICE);
+ } else if (!drop_thres)
+ goto use_orig_buf;
+ recycle:
+ recycle_rx_buf(adap, fl, fl->cidx);
+ return skb;
+ }
+
+ if (unlikely(fl->credits < drop_thres))
+ goto recycle;
+
+ use_orig_buf:
+ pci_unmap_single(adap->pdev, pci_unmap_addr(sd, dma_addr),
+ fl->buf_size, PCI_DMA_FROMDEVICE);
+ skb = sd->skb;
+ skb_put(skb, len);
+ __refill_fl(adap, fl);
+ return skb;
+}
+
+/**
+ * get_imm_packet - return the next ingress packet buffer from a response
+ * @resp: the response descriptor containing the packet data
+ *
+ * Return a packet containing the immediate data of the given response.
+ */
+static inline struct sk_buff *get_imm_packet(const struct rsp_desc *resp)
+{
+ struct sk_buff *skb = alloc_skb(IMMED_PKT_SIZE, GFP_ATOMIC);
+
+ if (skb) {
+ __skb_put(skb, IMMED_PKT_SIZE);
+ memcpy(skb->data, resp->imm_data, IMMED_PKT_SIZE);
+ }
+ return skb;
+}
+
+/**
+ * calc_tx_descs - calculate the number of Tx descriptors for a packet
+ * @skb: the packet
+ *
+ * Returns the number of Tx descriptors needed for the given Ethernet
+ * packet. Ethernet packets require addition of WR and CPL headers.
+ */
+static inline unsigned int calc_tx_descs(const struct sk_buff *skb)
+{
+ unsigned int flits;
+
+ if (skb->len <= WR_LEN - sizeof(struct cpl_tx_pkt))
+ return 1;
+
+ flits = sgl_len(skb_shinfo(skb)->nr_frags + 1) + 2;
+ if (skb_shinfo(skb)->gso_size)
+ flits++;
+ return flits_to_desc(flits);
+}
+
+/**
+ * make_sgl - populate a scatter/gather list for a packet
+ * @skb: the packet
+ * @sgp: the SGL to populate
+ * @start: start address of skb main body data to include in the SGL
+ * @len: length of skb main body data to include in the SGL
+ * @pdev: the PCI device
+ *
+ * Generates a scatter/gather list for the buffers that make up a packet
+ * and returns the SGL size in 8-byte words. The caller must size the SGL
+ * appropriately.
+ */
+static inline unsigned int make_sgl(const struct sk_buff *skb,
+ struct sg_ent *sgp, unsigned char *start,
+ unsigned int len, struct pci_dev *pdev)
+{
+ dma_addr_t mapping;
+ unsigned int i, j = 0, nfrags;
+
+ if (len) {
+ mapping = pci_map_single(pdev, start, len, PCI_DMA_TODEVICE);
+ sgp->len[0] = cpu_to_be32(len);
+ sgp->addr[0] = cpu_to_be64(mapping);
+ j = 1;
+ }
+
+ nfrags = skb_shinfo(skb)->nr_frags;
+ for (i = 0; i < nfrags; i++) {
+ skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
+
+ mapping = pci_map_page(pdev, frag->page, frag->page_offset,
+ frag->size, PCI_DMA_TODEVICE);
+ sgp->len[j] = cpu_to_be32(frag->size);
+ sgp->addr[j] = cpu_to_be64(mapping);
+ j ^= 1;
+ if (j == 0)
+ ++sgp;
+ }
+ if (j)
+ sgp->len[j] = 0;
+ return ((nfrags + (len != 0)) * 3) / 2 + j;
+}
+
+/**
+ * check_ring_tx_db - check and potentially ring a Tx queue's doorbell
+ * @adap: the adapter
+ * @q: the Tx queue
+ *
+ * Ring the doorbel if a Tx queue is asleep. There is a natural race,
+ * where the HW is going to sleep just after we checked, however,
+ * then the interrupt handler will detect the outstanding TX packet
+ * and ring the doorbell for us.
+ *
+ * When GTS is disabled we unconditionally ring the doorbell.
+ */
+static inline void check_ring_tx_db(struct adapter *adap, struct sge_txq *q)
+{
+#if USE_GTS
+ clear_bit(TXQ_LAST_PKT_DB, &q->flags);
+ if (test_and_set_bit(TXQ_RUNNING, &q->flags) == 0) {
+ set_bit(TXQ_LAST_PKT_DB, &q->flags);
+ t3_write_reg(adap, A_SG_KDOORBELL,
+ F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id));
+ }
+#else
+ wmb(); /* write descriptors before telling HW */
+ t3_write_reg(adap, A_SG_KDOORBELL,
+ F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id));
+#endif
+}
+
+static inline void wr_gen2(struct tx_desc *d, unsigned int gen)
+{
+#if SGE_NUM_GENBITS == 2
+ d->flit[TX_DESC_FLITS - 1] = cpu_to_be64(gen);
+#endif
+}
+
+/**
+ * write_wr_hdr_sgl - write a WR header and, optionally, SGL
+ * @ndesc: number of Tx descriptors spanned by the SGL
+ * @skb: the packet corresponding to the WR
+ * @d: first Tx descriptor to be written
+ * @pidx: index of above descriptors
+ * @q: the SGE Tx queue
+ * @sgl: the SGL
+ * @flits: number of flits to the start of the SGL in the first descriptor
+ * @sgl_flits: the SGL size in flits
+ * @gen: the Tx descriptor generation
+ * @wr_hi: top 32 bits of WR header based on WR type (big endian)
+ * @wr_lo: low 32 bits of WR header based on WR type (big endian)
+ *
+ * Write a work request header and an associated SGL. If the SGL is
+ * small enough to fit into one Tx descriptor it has already been written
+ * and we just need to write the WR header. Otherwise we distribute the
+ * SGL across the number of descriptors it spans.
+ */
+static void write_wr_hdr_sgl(unsigned int ndesc, struct sk_buff *skb,
+ struct tx_desc *d, unsigned int pidx,
+ const struct sge_txq *q,
+ const struct sg_ent *sgl,
+ unsigned int flits, unsigned int sgl_flits,
+ unsigned int gen, unsigned int wr_hi,
+ unsigned int wr_lo)
+{
+ struct work_request_hdr *wrp = (struct work_request_hdr *)d;
+ struct tx_sw_desc *sd = &q->sdesc[pidx];
+
+ sd->skb = skb;
+ if (need_skb_unmap()) {
+ struct unmap_info *ui = (struct unmap_info *)skb->cb;
+
+ ui->fragidx = 0;
+ ui->addr_idx = 0;
+ ui->sflit = flits;
+ }
+
+ if (likely(ndesc == 1)) {
+ skb->priority = pidx;
+ wrp->wr_hi = htonl(F_WR_SOP | F_WR_EOP | V_WR_DATATYPE(1) |
+ V_WR_SGLSFLT(flits)) | wr_hi;
+ wmb();
+ wrp->wr_lo = htonl(V_WR_LEN(flits + sgl_flits) |
+ V_WR_GEN(gen)) | wr_lo;
+ wr_gen2(d, gen);
+ } else {
+ unsigned int ogen = gen;
+ const u64 *fp = (const u64 *)sgl;
+ struct work_request_hdr *wp = wrp;
+
+ wrp->wr_hi = htonl(F_WR_SOP | V_WR_DATATYPE(1) |
+ V_WR_SGLSFLT(flits)) | wr_hi;
+
+ while (sgl_flits) {
+ unsigned int avail = WR_FLITS - flits;
+
+ if (avail > sgl_flits)
+ avail = sgl_flits;
+ memcpy(&d->flit[flits], fp, avail * sizeof(*fp));
+ sgl_flits -= avail;
+ ndesc--;
+ if (!sgl_flits)
+ break;
+
+ fp += avail;
+ d++;
+ sd++;
+ if (++pidx == q->size) {
+ pidx = 0;
+ gen ^= 1;
+ d = q->desc;
+ sd = q->sdesc;
+ }
+
+ sd->skb = skb;
+ wrp = (struct work_request_hdr *)d;
+ wrp->wr_hi = htonl(V_WR_DATATYPE(1) |
+ V_WR_SGLSFLT(1)) | wr_hi;
+ wrp->wr_lo = htonl(V_WR_LEN(min(WR_FLITS,
+ sgl_flits + 1)) |
+ V_WR_GEN(gen)) | wr_lo;
+ wr_gen2(d, gen);
+ flits = 1;
+ }
+ skb->priority = pidx;
+ wrp->wr_hi |= htonl(F_WR_EOP);
+ wmb();
+ wp->wr_lo = htonl(V_WR_LEN(WR_FLITS) | V_WR_GEN(ogen)) | wr_lo;
+ wr_gen2((struct tx_desc *)wp, ogen);
+ WARN_ON(ndesc != 0);
+ }
+}
+
+/**
+ * write_tx_pkt_wr - write a TX_PKT work request
+ * @adap: the adapter
+ * @skb: the packet to send
+ * @pi: the egress interface
+ * @pidx: index of the first Tx descriptor to write
+ * @gen: the generation value to use
+ * @q: the Tx queue
+ * @ndesc: number of descriptors the packet will occupy
+ * @compl: the value of the COMPL bit to use
+ *
+ * Generate a TX_PKT work request to send the supplied packet.
+ */
+static void write_tx_pkt_wr(struct adapter *adap, struct sk_buff *skb,
+ const struct port_info *pi,
+ unsigned int pidx, unsigned int gen,
+ struct sge_txq *q, unsigned int ndesc,
+ unsigned int compl)
+{
+ unsigned int flits, sgl_flits, cntrl, tso_info;
+ struct sg_ent *sgp, sgl[MAX_SKB_FRAGS / 2 + 1];
+ struct tx_desc *d = &q->desc[pidx];
+ struct cpl_tx_pkt *cpl = (struct cpl_tx_pkt *)d;
+
+ cpl->len = htonl(skb->len | 0x80000000);
+ cntrl = V_TXPKT_INTF(pi->port_id);
+
+ if (vlan_tx_tag_present(skb) && pi->vlan_grp)
+ cntrl |= F_TXPKT_VLAN_VLD | V_TXPKT_VLAN(vlan_tx_tag_get(skb));
+
+ tso_info = V_LSO_MSS(skb_shinfo(skb)->gso_size);
+ if (tso_info) {
+ int eth_type;
+ struct cpl_tx_pkt_lso *hdr = (struct cpl_tx_pkt_lso *)cpl;
+
+ d->flit[2] = 0;
+ cntrl |= V_TXPKT_OPCODE(CPL_TX_PKT_LSO);
+ hdr->cntrl = htonl(cntrl);
+ eth_type = skb->nh.raw - skb->data == ETH_HLEN ?
+ CPL_ETH_II : CPL_ETH_II_VLAN;
+ tso_info |= V_LSO_ETH_TYPE(eth_type) |
+ V_LSO_IPHDR_WORDS(skb->nh.iph->ihl) |
+ V_LSO_TCPHDR_WORDS(skb->h.th->doff);
+ hdr->lso_info = htonl(tso_info);
+ flits = 3;
+ } else {
+ cntrl |= V_TXPKT_OPCODE(CPL_TX_PKT);
+ cntrl |= F_TXPKT_IPCSUM_DIS; /* SW calculates IP csum */
+ cntrl |= V_TXPKT_L4CSUM_DIS(skb->ip_summed != CHECKSUM_PARTIAL);
+ cpl->cntrl = htonl(cntrl);
+
+ if (skb->len <= WR_LEN - sizeof(*cpl)) {
+ q->sdesc[pidx].skb = NULL;
+ if (!skb->data_len)
+ memcpy(&d->flit[2], skb->data, skb->len);
+ else
+ skb_copy_bits(skb, 0, &d->flit[2], skb->len);
+
+ flits = (skb->len + 7) / 8 + 2;
+ cpl->wr.wr_hi = htonl(V_WR_BCNTLFLT(skb->len & 7) |
+ V_WR_OP(FW_WROPCODE_TUNNEL_TX_PKT)
+ | F_WR_SOP | F_WR_EOP | compl);
+ wmb();
+ cpl->wr.wr_lo = htonl(V_WR_LEN(flits) | V_WR_GEN(gen) |
+ V_WR_TID(q->token));
+ wr_gen2(d, gen);
+ kfree_skb(skb);
+ return;
+ }
+
+ flits = 2;
+ }
+
+ sgp = ndesc == 1 ? (struct sg_ent *)&d->flit[flits] : sgl;
+ sgl_flits = make_sgl(skb, sgp, skb->data, skb_headlen(skb), adap->pdev);
+ if (need_skb_unmap())
+ ((struct unmap_info *)skb->cb)->len = skb_headlen(skb);
+
+ write_wr_hdr_sgl(ndesc, skb, d, pidx, q, sgl, flits, sgl_flits, gen,
+ htonl(V_WR_OP(FW_WROPCODE_TUNNEL_TX_PKT) | compl),
+ htonl(V_WR_TID(q->token)));
+}
+
+/**
+ * eth_xmit - add a packet to the Ethernet Tx queue
+ * @skb: the packet
+ * @dev: the egress net device
+ *
+ * Add a packet to an SGE Tx queue. Runs with softirqs disabled.
+ */
+int t3_eth_xmit(struct sk_buff *skb, struct net_device *dev)
+{
+ unsigned int ndesc, pidx, credits, gen, compl;
+ const struct port_info *pi = netdev_priv(dev);
+ struct adapter *adap = dev->priv;
+ struct sge_qset *qs = dev2qset(dev);
+ struct sge_txq *q = &qs->txq[TXQ_ETH];
+
+ /*
+ * The chip min packet length is 9 octets but play safe and reject
+ * anything shorter than an Ethernet header.
+ */
+ if (unlikely(skb->len < ETH_HLEN)) {
+ dev_kfree_skb(skb);
+ return NETDEV_TX_OK;
+ }
+
+ spin_lock(&q->lock);
+ reclaim_completed_tx(adap, q);
+
+ credits = q->size - q->in_use;
+ ndesc = calc_tx_descs(skb);
+
+ if (unlikely(credits < ndesc)) {
+ if (!netif_queue_stopped(dev)) {
+ netif_stop_queue(dev);
+ set_bit(TXQ_ETH, &qs->txq_stopped);
+ q->stops++;
+ dev_err(&adap->pdev->dev,
+ "%s: Tx ring %u full while queue awake!\n",
+ dev->name, q->cntxt_id & 7);
+ }
+ spin_unlock(&q->lock);
+ return NETDEV_TX_BUSY;
+ }
+
+ q->in_use += ndesc;
+ if (unlikely(credits - ndesc < q->stop_thres)) {
+ q->stops++;
+ netif_stop_queue(dev);
+ set_bit(TXQ_ETH, &qs->txq_stopped);
+#if !USE_GTS
+ if (should_restart_tx(q) &&
+ test_and_clear_bit(TXQ_ETH, &qs->txq_stopped)) {
+ q->restarts++;
+ netif_wake_queue(dev);
+ }
+#endif
+ }
+
+ gen = q->gen;
+ q->unacked += ndesc;
+ compl = (q->unacked & 8) << (S_WR_COMPL - 3);
+ q->unacked &= 7;
+ pidx = q->pidx;
+ q->pidx += ndesc;
+ if (q->pidx >= q->size) {
+ q->pidx -= q->size;
+ q->gen ^= 1;
+ }
+
+ /* update port statistics */
+ if (skb->ip_summed == CHECKSUM_COMPLETE)
+ qs->port_stats[SGE_PSTAT_TX_CSUM]++;
+ if (skb_shinfo(skb)->gso_size)
+ qs->port_stats[SGE_PSTAT_TSO]++;
+ if (vlan_tx_tag_present(skb) && pi->vlan_grp)
+ qs->port_stats[SGE_PSTAT_VLANINS]++;
+
+ dev->trans_start = jiffies;
+ spin_unlock(&q->lock);
+
+ /*
+ * We do not use Tx completion interrupts to free DMAd Tx packets.
+ * This is good for performamce but means that we rely on new Tx
+ * packets arriving to run the destructors of completed packets,
+ * which open up space in their sockets' send queues. Sometimes
+ * we do not get such new packets causing Tx to stall. A single
+ * UDP transmitter is a good example of this situation. We have
+ * a clean up timer that periodically reclaims completed packets
+ * but it doesn't run often enough (nor do we want it to) to prevent
+ * lengthy stalls. A solution to this problem is to run the
+ * destructor early, after the packet is queued but before it's DMAd.
+ * A cons is that we lie to socket memory accounting, but the amount
+ * of extra memory is reasonable (limited by the number of Tx
+ * descriptors), the packets do actually get freed quickly by new
+ * packets almost always, and for protocols like TCP that wait for
+ * acks to really free up the data the extra memory is even less.
+ * On the positive side we run the destructors on the sending CPU
+ * rather than on a potentially different completing CPU, usually a
+ * good thing. We also run them without holding our Tx queue lock,
+ * unlike what reclaim_completed_tx() would otherwise do.
+ *
+ * Run the destructor before telling the DMA engine about the packet
+ * to make sure it doesn't complete and get freed prematurely.
+ */
+ if (likely(!skb_shared(skb)))
+ skb_orphan(skb);
+
+ write_tx_pkt_wr(adap, skb, pi, pidx, gen, q, ndesc, compl);
+ check_ring_tx_db(adap, q);
+ return NETDEV_TX_OK;
+}
+
+/**
+ * write_imm - write a packet into a Tx descriptor as immediate data
+ * @d: the Tx descriptor to write
+ * @skb: the packet
+ * @len: the length of packet data to write as immediate data
+ * @gen: the generation bit value to write
+ *
+ * Writes a packet as immediate data into a Tx descriptor. The packet
+ * contains a work request at its beginning. We must write the packet
+ * carefully so the SGE doesn't read accidentally before it's written in
+ * its entirety.
+ */
+static inline void write_imm(struct tx_desc *d, struct sk_buff *skb,
+ unsigned int len, unsigned int gen)
+{
+ struct work_request_hdr *from = (struct work_request_hdr *)skb->data;
+ struct work_request_hdr *to = (struct work_request_hdr *)d;
+
+ memcpy(&to[1], &from[1], len - sizeof(*from));
+ to->wr_hi = from->wr_hi | htonl(F_WR_SOP | F_WR_EOP |
+ V_WR_BCNTLFLT(len & 7));
+ wmb();
+ to->wr_lo = from->wr_lo | htonl(V_WR_GEN(gen) |
+ V_WR_LEN((len + 7) / 8));
+ wr_gen2(d, gen);
+ kfree_skb(skb);
+}
+
+/**
+ * check_desc_avail - check descriptor availability on a send queue
+ * @adap: the adapter
+ * @q: the send queue
+ * @skb: the packet needing the descriptors
+ * @ndesc: the number of Tx descriptors needed
+ * @qid: the Tx queue number in its queue set (TXQ_OFLD or TXQ_CTRL)
+ *
+ * Checks if the requested number of Tx descriptors is available on an
+ * SGE send queue. If the queue is already suspended or not enough
+ * descriptors are available the packet is queued for later transmission.
+ * Must be called with the Tx queue locked.
+ *
+ * Returns 0 if enough descriptors are available, 1 if there aren't
+ * enough descriptors and the packet has been queued, and 2 if the caller
+ * needs to retry because there weren't enough descriptors at the
+ * beginning of the call but some freed up in the mean time.
+ */
+static inline int check_desc_avail(struct adapter *adap, struct sge_txq *q,
+ struct sk_buff *skb, unsigned int ndesc,
+ unsigned int qid)
+{
+ if (unlikely(!skb_queue_empty(&q->sendq))) {
+ addq_exit:__skb_queue_tail(&q->sendq, skb);
+ return 1;
+ }
+ if (unlikely(q->size - q->in_use < ndesc)) {
+ struct sge_qset *qs = txq_to_qset(q, qid);
+
+ set_bit(qid, &qs->txq_stopped);
+ smp_mb__after_clear_bit();
+
+ if (should_restart_tx(q) &&
+ test_and_clear_bit(qid, &qs->txq_stopped))
+ return 2;
+
+ q->stops++;
+ goto addq_exit;
+ }
+ return 0;
+}
+
+/**
+ * reclaim_completed_tx_imm - reclaim completed control-queue Tx descs
+ * @q: the SGE control Tx queue
+ *
+ * This is a variant of reclaim_completed_tx() that is used for Tx queues
+ * that send only immediate data (presently just the control queues) and
+ * thus do not have any sk_buffs to release.
+ */
+static inline void reclaim_completed_tx_imm(struct sge_txq *q)
+{
+ unsigned int reclaim = q->processed - q->cleaned;
+
+ q->in_use -= reclaim;
+ q->cleaned += reclaim;
+}
+
+static inline int immediate(const struct sk_buff *skb)
+{
+ return skb->len <= WR_LEN && !skb->data_len;
+}
+
+/**
+ * ctrl_xmit - send a packet through an SGE control Tx queue
+ * @adap: the adapter
+ * @q: the control queue
+ * @skb: the packet
+ *
+ * Send a packet through an SGE control Tx queue. Packets sent through
+ * a control queue must fit entirely as immediate data in a single Tx
+ * descriptor and have no page fragments.
+ */
+static int ctrl_xmit(struct adapter *adap, struct sge_txq *q,
+ struct sk_buff *skb)
+{
+ int ret;
+ struct work_request_hdr *wrp = (struct work_request_hdr *)skb->data;
+
+ if (unlikely(!immediate(skb))) {
+ WARN_ON(1);
+ dev_kfree_skb(skb);
+ return NET_XMIT_SUCCESS;
+ }
+
+ wrp->wr_hi |= htonl(F_WR_SOP | F_WR_EOP);
+ wrp->wr_lo = htonl(V_WR_TID(q->token));
+
+ spin_lock(&q->lock);
+ again:reclaim_completed_tx_imm(q);
+
+ ret = check_desc_avail(adap, q, skb, 1, TXQ_CTRL);
+ if (unlikely(ret)) {
+ if (ret == 1) {
+ spin_unlock(&q->lock);
+ return NET_XMIT_CN;
+ }
+ goto again;
+ }
+
+ write_imm(&q->desc[q->pidx], skb, skb->len, q->gen);
+
+ q->in_use++;
+ if (++q->pidx >= q->size) {
+ q->pidx = 0;
+ q->gen ^= 1;
+ }
+ spin_unlock(&q->lock);
+ wmb();
+ t3_write_reg(adap, A_SG_KDOORBELL,
+ F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id));
+ return NET_XMIT_SUCCESS;
+}
+
+/**
+ * restart_ctrlq - restart a suspended control queue
+ * @qs: the queue set cotaining the control queue
+ *
+ * Resumes transmission on a suspended Tx control queue.
+ */
+static void restart_ctrlq(unsigned long data)
+{
+ struct sk_buff *skb;
+ struct sge_qset *qs = (struct sge_qset *)data;
+ struct sge_txq *q = &qs->txq[TXQ_CTRL];
+ struct adapter *adap = qs->netdev->priv;
+
+ spin_lock(&q->lock);
+ again:reclaim_completed_tx_imm(q);
+
+ while (q->in_use < q->size && (skb = __skb_dequeue(&q->sendq)) != NULL) {
+
+ write_imm(&q->desc[q->pidx], skb, skb->len, q->gen);
+
+ if (++q->pidx >= q->size) {
+ q->pidx = 0;
+ q->gen ^= 1;
+ }
+ q->in_use++;
+ }
+
+ if (!skb_queue_empty(&q->sendq)) {
+ set_bit(TXQ_CTRL, &qs->txq_stopped);
+ smp_mb__after_clear_bit();
+
+ if (should_restart_tx(q) &&
+ test_and_clear_bit(TXQ_CTRL, &qs->txq_stopped))
+ goto again;
+ q->stops++;
+ }
+
+ spin_unlock(&q->lock);
+ t3_write_reg(adap, A_SG_KDOORBELL,
+ F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id));
+}
+
+/**
+ * write_ofld_wr - write an offload work request
+ * @adap: the adapter
+ * @skb: the packet to send
+ * @q: the Tx queue
+ * @pidx: index of the first Tx descriptor to write
+ * @gen: the generation value to use
+ * @ndesc: number of descriptors the packet will occupy
+ *
+ * Write an offload work request to send the supplied packet. The packet
+ * data already carry the work request with most fields populated.
+ */
+static void write_ofld_wr(struct adapter *adap, struct sk_buff *skb,
+ struct sge_txq *q, unsigned int pidx,
+ unsigned int gen, unsigned int ndesc)
+{
+ unsigned int sgl_flits, flits;
+ struct work_request_hdr *from;
+ struct sg_ent *sgp, sgl[MAX_SKB_FRAGS / 2 + 1];
+ struct tx_desc *d = &q->desc[pidx];
+
+ if (immediate(skb)) {
+ q->sdesc[pidx].skb = NULL;
+ write_imm(d, skb, skb->len, gen);
+ return;
+ }
+
+ /* Only TX_DATA builds SGLs */
+
+ from = (struct work_request_hdr *)skb->data;
+ memcpy(&d->flit[1], &from[1], skb->h.raw - skb->data - sizeof(*from));
+
+ flits = (skb->h.raw - skb->data) / 8;
+ sgp = ndesc == 1 ? (struct sg_ent *)&d->flit[flits] : sgl;
+ sgl_flits = make_sgl(skb, sgp, skb->h.raw, skb->tail - skb->h.raw,
+ adap->pdev);
+ if (need_skb_unmap())
+ ((struct unmap_info *)skb->cb)->len = skb->tail - skb->h.raw;
+
+ write_wr_hdr_sgl(ndesc, skb, d, pidx, q, sgl, flits, sgl_flits,
+ gen, from->wr_hi, from->wr_lo);
+}
+
+/**
+ * calc_tx_descs_ofld - calculate # of Tx descriptors for an offload packet
+ * @skb: the packet
+ *
+ * Returns the number of Tx descriptors needed for the given offload
+ * packet. These packets are already fully constructed.
+ */
+static inline unsigned int calc_tx_descs_ofld(const struct sk_buff *skb)
+{
+ unsigned int flits, cnt = skb_shinfo(skb)->nr_frags;
+
+ if (skb->len <= WR_LEN && cnt == 0)
+ return 1; /* packet fits as immediate data */
+
+ flits = (skb->h.raw - skb->data) / 8; /* headers */
+ if (skb->tail != skb->h.raw)
+ cnt++;
+ return flits_to_desc(flits + sgl_len(cnt));
+}
+
+/**
+ * ofld_xmit - send a packet through an offload queue
+ * @adap: the adapter
+ * @q: the Tx offload queue
+ * @skb: the packet
+ *
+ * Send an offload packet through an SGE offload queue.
+ */
+static int ofld_xmit(struct adapter *adap, struct sge_txq *q,
+ struct sk_buff *skb)
+{
+ int ret;
+ unsigned int ndesc = calc_tx_descs_ofld(skb), pidx, gen;
+
+ spin_lock(&q->lock);
+ again:reclaim_completed_tx(adap, q);
+
+ ret = check_desc_avail(adap, q, skb, ndesc, TXQ_OFLD);
+ if (unlikely(ret)) {
+ if (ret == 1) {
+ skb->priority = ndesc; /* save for restart */
+ spin_unlock(&q->lock);
+ return NET_XMIT_CN;
+ }
+ goto again;
+ }
+
+ gen = q->gen;
+ q->in_use += ndesc;
+ pidx = q->pidx;
+ q->pidx += ndesc;
+ if (q->pidx >= q->size) {
+ q->pidx -= q->size;
+ q->gen ^= 1;
+ }
+ spin_unlock(&q->lock);
+
+ write_ofld_wr(adap, skb, q, pidx, gen, ndesc);
+ check_ring_tx_db(adap, q);
+ return NET_XMIT_SUCCESS;
+}
+
+/**
+ * restart_offloadq - restart a suspended offload queue
+ * @qs: the queue set cotaining the offload queue
+ *
+ * Resumes transmission on a suspended Tx offload queue.
+ */
+static void restart_offloadq(unsigned long data)
+{
+ struct sk_buff *skb;
+ struct sge_qset *qs = (struct sge_qset *)data;
+ struct sge_txq *q = &qs->txq[TXQ_OFLD];
+ struct adapter *adap = qs->netdev->priv;
+
+ spin_lock(&q->lock);
+ again:reclaim_completed_tx(adap, q);
+
+ while ((skb = skb_peek(&q->sendq)) != NULL) {
+ unsigned int gen, pidx;
+ unsigned int ndesc = skb->priority;
+
+ if (unlikely(q->size - q->in_use < ndesc)) {
+ set_bit(TXQ_OFLD, &qs->txq_stopped);
+ smp_mb__after_clear_bit();
+
+ if (should_restart_tx(q) &&
+ test_and_clear_bit(TXQ_OFLD, &qs->txq_stopped))
+ goto again;
+ q->stops++;
+ break;
+ }
+
+ gen = q->gen;
+ q->in_use += ndesc;
+ pidx = q->pidx;
+ q->pidx += ndesc;
+ if (q->pidx >= q->size) {
+ q->pidx -= q->size;
+ q->gen ^= 1;
+ }
+ __skb_unlink(skb, &q->sendq);
+ spin_unlock(&q->lock);
+
+ write_ofld_wr(adap, skb, q, pidx, gen, ndesc);
+ spin_lock(&q->lock);
+ }
+ spin_unlock(&q->lock);
+
+#if USE_GTS
+ set_bit(TXQ_RUNNING, &q->flags);
+ set_bit(TXQ_LAST_PKT_DB, &q->flags);
+#endif
+ t3_write_reg(adap, A_SG_KDOORBELL,
+ F_SELEGRCNTX | V_EGRCNTX(q->cntxt_id));
+}
+
+/**
+ * queue_set - return the queue set a packet should use
+ * @skb: the packet
+ *
+ * Maps a packet to the SGE queue set it should use. The desired queue
+ * set is carried in bits 1-3 in the packet's priority.
+ */
+static inline int queue_set(const struct sk_buff *skb)
+{
+ return skb->priority >> 1;
+}
+
+/**
+ * is_ctrl_pkt - return whether an offload packet is a control packet
+ * @skb: the packet
+ *
+ * Determines whether an offload packet should use an OFLD or a CTRL
+ * Tx queue. This is indicated by bit 0 in the packet's priority.
+ */
+static inline int is_ctrl_pkt(const struct sk_buff *skb)
+{
+ return skb->priority & 1;
+}
+
+/**
+ * t3_offload_tx - send an offload packet
+ * @tdev: the offload device to send to
+ * @skb: the packet
+ *
+ * Sends an offload packet. We use the packet priority to select the
+ * appropriate Tx queue as follows: bit 0 indicates whether the packet
+ * should be sent as regular or control, bits 1-3 select the queue set.
+ */
+int t3_offload_tx(struct t3cdev *tdev, struct sk_buff *skb)
+{
+ struct adapter *adap = tdev2adap(tdev);
+ struct sge_qset *qs = &adap->sge.qs[queue_set(skb)];
+
+ if (unlikely(is_ctrl_pkt(skb)))
+ return ctrl_xmit(adap, &qs->txq[TXQ_CTRL], skb);
+
+ return ofld_xmit(adap, &qs->txq[TXQ_OFLD], skb);
+}
+
+/**
+ * offload_enqueue - add an offload packet to an SGE offload receive queue
+ * @q: the SGE response queue
+ * @skb: the packet
+ *
+ * Add a new offload packet to an SGE response queue's offload packet
+ * queue. If the packet is the first on the queue it schedules the RX
+ * softirq to process the queue.
+ */
+static inline void offload_enqueue(struct sge_rspq *q, struct sk_buff *skb)
+{
+ skb->next = skb->prev = NULL;
+ if (q->rx_tail)
+ q->rx_tail->next = skb;
+ else {
+ struct sge_qset *qs = rspq_to_qset(q);
+
+ if (__netif_rx_schedule_prep(qs->netdev))
+ __netif_rx_schedule(qs->netdev);
+ q->rx_head = skb;
+ }
+ q->rx_tail = skb;
+}
+
+/**
+ * deliver_partial_bundle - deliver a (partial) bundle of Rx offload pkts
+ * @tdev: the offload device that will be receiving the packets
+ * @q: the SGE response queue that assembled the bundle
+ * @skbs: the partial bundle
+ * @n: the number of packets in the bundle
+ *
+ * Delivers a (partial) bundle of Rx offload packets to an offload device.
+ */
+static inline void deliver_partial_bundle(struct t3cdev *tdev,
+ struct sge_rspq *q,
+ struct sk_buff *skbs[], int n)
+{
+ if (n) {
+ q->offload_bundles++;
+ tdev->recv(tdev, skbs, n);
+ }
+}
+
+/**
+ * ofld_poll - NAPI handler for offload packets in interrupt mode
+ * @dev: the network device doing the polling
+ * @budget: polling budget
+ *
+ * The NAPI handler for offload packets when a response queue is serviced
+ * by the hard interrupt handler, i.e., when it's operating in non-polling
+ * mode. Creates small packet batches and sends them through the offload
+ * receive handler. Batches need to be of modest size as we do prefetches
+ * on the packets in each.
+ */
+static int ofld_poll(struct net_device *dev, int *budget)
+{
+ struct adapter *adapter = dev->priv;
+ struct sge_qset *qs = dev2qset(dev);
+ struct sge_rspq *q = &qs->rspq;
+ int work_done, limit = min(*budget, dev->quota), avail = limit;
+
+ while (avail) {
+ struct sk_buff *head, *tail, *skbs[RX_BUNDLE_SIZE];
+ int ngathered;
+
+ spin_lock_irq(&q->lock);
+ head = q->rx_head;
+ if (!head) {
+ work_done = limit - avail;
+ *budget -= work_done;
+ dev->quota -= work_done;
+ __netif_rx_complete(dev);
+ spin_unlock_irq(&q->lock);
+ return 0;
+ }
+
+ tail = q->rx_tail;
+ q->rx_head = q->rx_tail = NULL;
+ spin_unlock_irq(&q->lock);
+
+ for (ngathered = 0; avail && head; avail--) {
+ prefetch(head->data);
+ skbs[ngathered] = head;
+ head = head->next;
+ skbs[ngathered]->next = NULL;
+ if (++ngathered == RX_BUNDLE_SIZE) {
+ q->offload_bundles++;
+ adapter->tdev.recv(&adapter->tdev, skbs,
+ ngathered);
+ ngathered = 0;
+ }
+ }
+ if (head) { /* splice remaining packets back onto Rx queue */
+ spin_lock_irq(&q->lock);
+ tail->next = q->rx_head;
+ if (!q->rx_head)
+ q->rx_tail = tail;
+ q->rx_head = head;
+ spin_unlock_irq(&q->lock);
+ }
+ deliver_partial_bundle(&adapter->tdev, q, skbs, ngathered);
+ }
+ work_done = limit - avail;
+ *budget -= work_done;
+ dev->quota -= work_done;
+ return 1;
+}
+
+/**
+ * rx_offload - process a received offload packet
+ * @tdev: the offload device receiving the packet
+ * @rq: the response queue that received the packet
+ * @skb: the packet
+ * @rx_gather: a gather list of packets if we are building a bundle
+ * @gather_idx: index of the next available slot in the bundle
+ *
+ * Process an ingress offload pakcet and add it to the offload ingress
+ * queue. Returns the index of the next available slot in the bundle.
+ */
+static inline int rx_offload(struct t3cdev *tdev, struct sge_rspq *rq,
+ struct sk_buff *skb, struct sk_buff *rx_gather[],
+ unsigned int gather_idx)
+{
+ rq->offload_pkts++;
+ skb->mac.raw = skb->nh.raw = skb->h.raw = skb->data;
+
+ if (rq->polling) {
+ rx_gather[gather_idx++] = skb;
+ if (gather_idx == RX_BUNDLE_SIZE) {
+ tdev->recv(tdev, rx_gather, RX_BUNDLE_SIZE);
+ gather_idx = 0;
+ rq->offload_bundles++;
+ }
+ } else
+ offload_enqueue(rq, skb);
+
+ return gather_idx;
+}
+
+/**
+ * update_tx_completed - update the number of processed Tx descriptors
+ * @qs: the queue set to update
+ * @idx: which Tx queue within the set to update
+ * @credits: number of new processed descriptors
+ * @tx_completed: accumulates credits for the queues
+ *
+ * Updates the number of completed Tx descriptors for a queue set's Tx
+ * queue. On UP systems we updated the information immediately but on
+ * MP we accumulate the credits locally and update the Tx queue when we
+ * reach a threshold to avoid cache-line bouncing.
+ */
+static inline void update_tx_completed(struct sge_qset *qs, int idx,
+ unsigned int credits,
+ unsigned int tx_completed[])
+{
+#ifdef CONFIG_SMP
+ tx_completed[idx] += credits;
+ if (tx_completed[idx] > 32) {
+ qs->txq[idx].processed += tx_completed[idx];
+ tx_completed[idx] = 0;
+ }
+#else
+ qs->txq[idx].processed += credits;
+#endif
+}
+
+/**
+ * restart_tx - check whether to restart suspended Tx queues
+ * @qs: the queue set to resume
+ *
+ * Restarts suspended Tx queues of an SGE queue set if they have enough
+ * free resources to resume operation.
+ */
+static void restart_tx(struct sge_qset *qs)
+{
+ if (test_bit(TXQ_ETH, &qs->txq_stopped) &&
+ should_restart_tx(&qs->txq[TXQ_ETH]) &&
+ test_and_clear_bit(TXQ_ETH, &qs->txq_stopped)) {
+ qs->txq[TXQ_ETH].restarts++;
+ if (netif_running(qs->netdev))
+ netif_wake_queue(qs->netdev);
+ }
+
+ if (test_bit(TXQ_OFLD, &qs->txq_stopped) &&
+ should_restart_tx(&qs->txq[TXQ_OFLD]) &&
+ test_and_clear_bit(TXQ_OFLD, &qs->txq_stopped)) {
+ qs->txq[TXQ_OFLD].restarts++;
+ tasklet_schedule(&qs->txq[TXQ_OFLD].qresume_tsk);
+ }
+ if (test_bit(TXQ_CTRL, &qs->txq_stopped) &&
+ should_restart_tx(&qs->txq[TXQ_CTRL]) &&
+ test_and_clear_bit(TXQ_CTRL, &qs->txq_stopped)) {
+ qs->txq[TXQ_CTRL].restarts++;
+ tasklet_schedule(&qs->txq[TXQ_CTRL].qresume_tsk);
+ }
+}
+
+/**
+ * rx_eth - process an ingress ethernet packet
+ * @adap: the adapter
+ * @rq: the response queue that received the packet
+ * @skb: the packet
+ * @pad: amount of padding at the start of the buffer
+ *
+ * Process an ingress ethernet pakcet and deliver it to the stack.
+ * The padding is 2 if the packet was delivered in an Rx buffer and 0
+ * if it was immediate data in a response.
+ */
+static void rx_eth(struct adapter *adap, struct sge_rspq *rq,
+ struct sk_buff *skb, int pad)
+{
+ struct cpl_rx_pkt *p = (struct cpl_rx_pkt *)(skb->data + pad);
+ struct port_info *pi;
+
+ rq->eth_pkts++;
+ skb_pull(skb, sizeof(*p) + pad);
+ skb->dev = adap->port[p->iff];
+ skb->dev->last_rx = jiffies;
+ skb->protocol = eth_type_trans(skb, skb->dev);
+ pi = netdev_priv(skb->dev);
+ if (pi->rx_csum_offload && p->csum_valid && p->csum == 0xffff &&
+ !p->fragment) {
+ rspq_to_qset(rq)->port_stats[SGE_PSTAT_RX_CSUM_GOOD]++;
+ skb->ip_summed = CHECKSUM_UNNECESSARY;
+ } else
+ skb->ip_summed = CHECKSUM_NONE;
+
+ if (unlikely(p->vlan_valid)) {
+ struct vlan_group *grp = pi->vlan_grp;
+
+ rspq_to_qset(rq)->port_stats[SGE_PSTAT_VLANEX]++;
+ if (likely(grp))
+ __vlan_hwaccel_rx(skb, grp, ntohs(p->vlan),
+ rq->polling);
+ else
+ dev_kfree_skb_any(skb);
+ } else if (rq->polling)
+ netif_receive_skb(skb);
+ else
+ netif_rx(skb);
+}
+
+/**
+ * handle_rsp_cntrl_info - handles control information in a response
+ * @qs: the queue set corresponding to the response
+ * @flags: the response control flags
+ * @tx_completed: accumulates completion credits for the Tx queues
+ *
+ * Handles the control information of an SGE response, such as GTS
+ * indications and completion credits for the queue set's Tx queues.
+ */
+static inline void handle_rsp_cntrl_info(struct sge_qset *qs, u32 flags,
+ unsigned int tx_completed[])
+{
+ unsigned int credits;
+
+#if USE_GTS
+ if (flags & F_RSPD_TXQ0_GTS)
+ clear_bit(TXQ_RUNNING, &qs->txq[TXQ_ETH].flags);
+#endif
+
+ /* ETH credits are already coalesced, return them immediately. */
+ credits = G_RSPD_TXQ0_CR(flags);
+ if (credits)
+ qs->txq[TXQ_ETH].processed += credits;
+
+# if USE_GTS
+ if (flags & F_RSPD_TXQ1_GTS)
+ clear_bit(TXQ_RUNNING, &qs->txq[TXQ_OFLD].flags);
+# endif
+ update_tx_completed(qs, TXQ_OFLD, G_RSPD_TXQ1_CR(flags), tx_completed);
+ update_tx_completed(qs, TXQ_CTRL, G_RSPD_TXQ2_CR(flags), tx_completed);
+}
+
+/**
+ * flush_tx_completed - returns accumulated Tx completions to Tx queues
+ * @qs: the queue set to update
+ * @tx_completed: pending completion credits to return to Tx queues
+ *
+ * Updates the number of completed Tx descriptors for a queue set's Tx
+ * queues with the credits pending in @tx_completed. This does something
+ * only on MP systems as on UP systems we return the credits immediately.
+ */
+static inline void flush_tx_completed(struct sge_qset *qs,
+ unsigned int tx_completed[])
+{
+#if defined(CONFIG_SMP)
+ if (tx_completed[TXQ_OFLD])
+ qs->txq[TXQ_OFLD].processed += tx_completed[TXQ_OFLD];
+ if (tx_completed[TXQ_CTRL])
+ qs->txq[TXQ_CTRL].processed += tx_completed[TXQ_CTRL];
+#endif
+}
+
+/**
+ * check_ring_db - check if we need to ring any doorbells
+ * @adapter: the adapter
+ * @qs: the queue set whose Tx queues are to be examined
+ * @sleeping: indicates which Tx queue sent GTS
+ *
+ * Checks if some of a queue set's Tx queues need to ring their doorbells
+ * to resume transmission after idling while they still have unprocessed
+ * descriptors.
+ */
+static void check_ring_db(struct adapter *adap, struct sge_qset *qs,
+ unsigned int sleeping)
+{
+ if (sleeping & F_RSPD_TXQ0_GTS) {
+ struct sge_txq *txq = &qs->txq[TXQ_ETH];
+
+ if (txq->cleaned + txq->in_use != txq->processed &&
+ !test_and_set_bit(TXQ_LAST_PKT_DB, &txq->flags)) {
+ set_bit(TXQ_RUNNING, &txq->flags);
+ t3_write_reg(adap, A_SG_KDOORBELL, F_SELEGRCNTX |
+ V_EGRCNTX(txq->cntxt_id));
+ }
+ }
+
+ if (sleeping & F_RSPD_TXQ1_GTS) {
+ struct sge_txq *txq = &qs->txq[TXQ_OFLD];
+
+ if (txq->cleaned + txq->in_use != txq->processed &&
+ !test_and_set_bit(TXQ_LAST_PKT_DB, &txq->flags)) {
+ set_bit(TXQ_RUNNING, &txq->flags);
+ t3_write_reg(adap, A_SG_KDOORBELL, F_SELEGRCNTX |
+ V_EGRCNTX(txq->cntxt_id));
+ }
+ }
+}
+
+/**
+ * is_new_response - check if a response is newly written
+ * @r: the response descriptor
+ * @q: the response queue
+ *
+ * Returns true if a response descriptor contains a yet unprocessed
+ * response.
+ */
+static inline int is_new_response(const struct rsp_desc *r,
+ const struct sge_rspq *q)
+{
+ return (r->intr_gen & F_RSPD_GEN2) == q->gen;
+}
+
+#define RSPD_GTS_MASK (F_RSPD_TXQ0_GTS | F_RSPD_TXQ1_GTS)
+#define RSPD_CTRL_MASK (RSPD_GTS_MASK | \
+ V_RSPD_TXQ0_CR(M_RSPD_TXQ0_CR) | \
+ V_RSPD_TXQ1_CR(M_RSPD_TXQ1_CR) | \
+ V_RSPD_TXQ2_CR(M_RSPD_TXQ2_CR))
+
+/* How long to delay the next interrupt in case of memory shortage, in 0.1us. */
+#define NOMEM_INTR_DELAY 2500
+
+/**
+ * process_responses - process responses from an SGE response queue
+ * @adap: the adapter
+ * @qs: the queue set to which the response queue belongs
+ * @budget: how many responses can be processed in this round
+ *
+ * Process responses from an SGE response queue up to the supplied budget.
+ * Responses include received packets as well as credits and other events
+ * for the queues that belong to the response queue's queue set.
+ * A negative budget is effectively unlimited.
+ *
+ * Additionally choose the interrupt holdoff time for the next interrupt
+ * on this queue. If the system is under memory shortage use a fairly
+ * long delay to help recovery.
+ */
+static int process_responses(struct adapter *adap, struct sge_qset *qs,
+ int budget)
+{
+ struct sge_rspq *q = &qs->rspq;
+ struct rsp_desc *r = &q->desc[q->cidx];
+ int budget_left = budget;
+ unsigned int sleeping = 0, tx_completed[3] = { 0, 0, 0 };
+ struct sk_buff *offload_skbs[RX_BUNDLE_SIZE];
+ int ngathered = 0;
+
+ q->next_holdoff = q->holdoff_tmr;
+
+ while (likely(budget_left && is_new_response(r, q))) {
+ int eth, ethpad = 0;
+ struct sk_buff *skb = NULL;
+ u32 len, flags = ntohl(r->flags);
+ u32 rss_hi = *(const u32 *)r, rss_lo = r->rss_hdr.rss_hash_val;
+
+ eth = r->rss_hdr.opcode == CPL_RX_PKT;
+
+ if (unlikely(flags & F_RSPD_ASYNC_NOTIF)) {
+ skb = alloc_skb(AN_PKT_SIZE, GFP_ATOMIC);
+ if (!skb)
+ goto no_mem;
+
+ memcpy(__skb_put(skb, AN_PKT_SIZE), r, AN_PKT_SIZE);
+ skb->data[0] = CPL_ASYNC_NOTIF;
+ rss_hi = htonl(CPL_ASYNC_NOTIF << 24);
+ q->async_notif++;
+ } else if (flags & F_RSPD_IMM_DATA_VALID) {
+ skb = get_imm_packet(r);
+ if (unlikely(!skb)) {
+ no_mem:
+ q->next_holdoff = NOMEM_INTR_DELAY;
+ q->nomem++;
+ /* consume one credit since we tried */
+ budget_left--;
+ break;
+ }
+ q->imm_data++;
+ } else if ((len = ntohl(r->len_cq)) != 0) {
+ struct sge_fl *fl;
+
+ fl = (len & F_RSPD_FLQ) ? &qs->fl[1] : &qs->fl[0];
+ fl->credits--;
+ skb = get_packet(adap, fl, G_RSPD_LEN(len),
+ eth ? SGE_RX_DROP_THRES : 0);
+ if (!skb)
+ q->rx_drops++;
+ else if (r->rss_hdr.opcode == CPL_TRACE_PKT)
+ __skb_pull(skb, 2);
+ ethpad = 2;
+ if (++fl->cidx == fl->size)
+ fl->cidx = 0;
+ } else
+ q->pure_rsps++;
+
+ if (flags & RSPD_CTRL_MASK) {
+ sleeping |= flags & RSPD_GTS_MASK;
+ handle_rsp_cntrl_info(qs, flags, tx_completed);
+ }
+
+ r++;
+ if (unlikely(++q->cidx == q->size)) {
+ q->cidx = 0;
+ q->gen ^= 1;
+ r = q->desc;
+ }
+ prefetch(r);
+
+ if (++q->credits >= (q->size / 4)) {
+ refill_rspq(adap, q, q->credits);
+ q->credits = 0;
+ }
+
+ if (likely(skb != NULL)) {
+ if (eth)
+ rx_eth(adap, q, skb, ethpad);
+ else {
+ /* Preserve the RSS info in csum & priority */
+ skb->csum = rss_hi;
+ skb->priority = rss_lo;
+ ngathered = rx_offload(&adap->tdev, q, skb,
+ offload_skbs, ngathered);
+ }
+ }
+
+ --budget_left;
+ }
+
+ flush_tx_completed(qs, tx_completed);
+ deliver_partial_bundle(&adap->tdev, q, offload_skbs, ngathered);
+ if (sleeping)
+ check_ring_db(adap, qs, sleeping);
+
+ smp_mb(); /* commit Tx queue .processed updates */
+ if (unlikely(qs->txq_stopped != 0))
+ restart_tx(qs);
+
+ budget -= budget_left;
+ return budget;
+}
+
+static inline int is_pure_response(const struct rsp_desc *r)
+{
+ u32 n = ntohl(r->flags) & (F_RSPD_ASYNC_NOTIF | F_RSPD_IMM_DATA_VALID);
+
+ return (n | r->len_cq) == 0;
+}
+
+/**
+ * napi_rx_handler - the NAPI handler for Rx processing
+ * @dev: the net device
+ * @budget: how many packets we can process in this round
+ *
+ * Handler for new data events when using NAPI.
+ */
+static int napi_rx_handler(struct net_device *dev, int *budget)
+{
+ struct adapter *adap = dev->priv;
+ struct sge_qset *qs = dev2qset(dev);
+ int effective_budget = min(*budget, dev->quota);
+
+ int work_done = process_responses(adap, qs, effective_budget);
+ *budget -= work_done;
+ dev->quota -= work_done;
+
+ if (work_done >= effective_budget)
+ return 1;
+
+ netif_rx_complete(dev);
+
+ /*
+ * Because we don't atomically flush the following write it is
+ * possible that in very rare cases it can reach the device in a way
+ * that races with a new response being written plus an error interrupt
+ * causing the NAPI interrupt handler below to return unhandled status
+ * to the OS. To protect against this would require flushing the write
+ * and doing both the write and the flush with interrupts off. Way too
+ * expensive and unjustifiable given the rarity of the race.
+ *
+ * The race cannot happen at all with MSI-X.
+ */
+ t3_write_reg(adap, A_SG_GTS, V_RSPQ(qs->rspq.cntxt_id) |
+ V_NEWTIMER(qs->rspq.next_holdoff) |
+ V_NEWINDEX(qs->rspq.cidx));
+ return 0;
+}
+
+/*
+ * Returns true if the device is already scheduled for polling.
+ */
+static inline int napi_is_scheduled(struct net_device *dev)
+{
+ return test_bit(__LINK_STATE_RX_SCHED, &dev->state);
+}
+
+/**
+ * process_pure_responses - process pure responses from a response queue
+ * @adap: the adapter
+ * @qs: the queue set owning the response queue
+ * @r: the first pure response to process
+ *
+ * A simpler version of process_responses() that handles only pure (i.e.,
+ * non data-carrying) responses. Such respones are too light-weight to
+ * justify calling a softirq under NAPI, so we handle them specially in
+ * the interrupt handler. The function is called with a pointer to a
+ * response, which the caller must ensure is a valid pure response.
+ *
+ * Returns 1 if it encounters a valid data-carrying response, 0 otherwise.
+ */
+static int process_pure_responses(struct adapter *adap, struct sge_qset *qs,
+ struct rsp_desc *r)
+{
+ struct sge_rspq *q = &qs->rspq;
+ unsigned int sleeping = 0, tx_completed[3] = { 0, 0, 0 };
+
+ do {
+ u32 flags = ntohl(r->flags);
+
+ r++;
+ if (unlikely(++q->cidx == q->size)) {
+ q->cidx = 0;
+ q->gen ^= 1;
+ r = q->desc;
+ }
+ prefetch(r);
+
+ if (flags & RSPD_CTRL_MASK) {
+ sleeping |= flags & RSPD_GTS_MASK;
+ handle_rsp_cntrl_info(qs, flags, tx_completed);
+ }
+
+ q->pure_rsps++;
+ if (++q->credits >= (q->size / 4)) {
+ refill_rspq(adap, q, q->credits);
+ q->credits = 0;
+ }
+ } while (is_new_response(r, q) && is_pure_response(r));
+
+ flush_tx_completed(qs, tx_completed);
+
+ if (sleeping)
+ check_ring_db(adap, qs, sleeping);
+
+ smp_mb(); /* commit Tx queue .processed updates */
+ if (unlikely(qs->txq_stopped != 0))
+ restart_tx(qs);
+
+ return is_new_response(r, q);
+}
+
+/**
+ * handle_responses - decide what to do with new responses in NAPI mode
+ * @adap: the adapter
+ * @q: the response queue
+ *
+ * This is used by the NAPI interrupt handlers to decide what to do with
+ * new SGE responses. If there are no new responses it returns -1. If
+ * there are new responses and they are pure (i.e., non-data carrying)
+ * it handles them straight in hard interrupt context as they are very
+ * cheap and don't deliver any packets. Finally, if there are any data
+ * signaling responses it schedules the NAPI handler. Returns 1 if it
+ * schedules NAPI, 0 if all new responses were pure.
+ *
+ * The caller must ascertain NAPI is not already running.
+ */
+static inline int handle_responses(struct adapter *adap, struct sge_rspq *q)
+{
+ struct sge_qset *qs = rspq_to_qset(q);
+ struct rsp_desc *r = &q->desc[q->cidx];
+
+ if (!is_new_response(r, q))
+ return -1;
+ if (is_pure_response(r) && process_pure_responses(adap, qs, r) == 0) {
+ t3_write_reg(adap, A_SG_GTS, V_RSPQ(q->cntxt_id) |
+ V_NEWTIMER(q->holdoff_tmr) | V_NEWINDEX(q->cidx));
+ return 0;
+ }
+ if (likely(__netif_rx_schedule_prep(qs->netdev)))
+ __netif_rx_schedule(qs->netdev);
+ return 1;
+}
+
+/*
+ * The MSI-X interrupt handler for an SGE response queue for the non-NAPI case
+ * (i.e., response queue serviced in hard interrupt).
+ */
+irqreturn_t t3_sge_intr_msix(int irq, void *cookie)
+{
+ struct sge_qset *qs = cookie;
+ struct adapter *adap = qs->netdev->priv;
+ struct sge_rspq *q = &qs->rspq;
+
+ spin_lock(&q->lock);
+ if (process_responses(adap, qs, -1) == 0)
+ q->unhandled_irqs++;
+ t3_write_reg(adap, A_SG_GTS, V_RSPQ(q->cntxt_id) |
+ V_NEWTIMER(q->next_holdoff) | V_NEWINDEX(q->cidx));
+ spin_unlock(&q->lock);
+ return IRQ_HANDLED;
+}
+
+/*
+ * The MSI-X interrupt handler for an SGE response queue for the NAPI case
+ * (i.e., response queue serviced by NAPI polling).
+ */
+irqreturn_t t3_sge_intr_msix_napi(int irq, void *cookie)
+{
+ struct sge_qset *qs = cookie;
+ struct adapter *adap = qs->netdev->priv;
+ struct sge_rspq *q = &qs->rspq;
+
+ spin_lock(&q->lock);
+ BUG_ON(napi_is_scheduled(qs->netdev));
+
+ if (handle_responses(adap, q) < 0)
+ q->unhandled_irqs++;
+ spin_unlock(&q->lock);
+ return IRQ_HANDLED;
+}
+
+/*
+ * The non-NAPI MSI interrupt handler. This needs to handle data events from
+ * SGE response queues as well as error and other async events as they all use
+ * the same MSI vector. We use one SGE response queue per port in this mode
+ * and protect all response queues with queue 0's lock.
+ */
+static irqreturn_t t3_intr_msi(int irq, void *cookie)
+{
+ int new_packets = 0;
+ struct adapter *adap = cookie;
+ struct sge_rspq *q = &adap->sge.qs[0].rspq;
+
+ spin_lock(&q->lock);
+
+ if (process_responses(adap, &adap->sge.qs[0], -1)) {
+ t3_write_reg(adap, A_SG_GTS, V_RSPQ(q->cntxt_id) |
+ V_NEWTIMER(q->next_holdoff) | V_NEWINDEX(q->cidx));
+ new_packets = 1;
+ }
+
+ if (adap->params.nports == 2 &&
+ process_responses(adap, &adap->sge.qs[1], -1)) {
+ struct sge_rspq *q1 = &adap->sge.qs[1].rspq;
+
+ t3_write_reg(adap, A_SG_GTS, V_RSPQ(q1->cntxt_id) |
+ V_NEWTIMER(q1->next_holdoff) |
+ V_NEWINDEX(q1->cidx));
+ new_packets = 1;
+ }
+
+ if (!new_packets && t3_slow_intr_handler(adap) == 0)
+ q->unhandled_irqs++;
+
+ spin_unlock(&q->lock);
+ return IRQ_HANDLED;
+}
+
+static int rspq_check_napi(struct net_device *dev, struct sge_rspq *q)
+{
+ if (!napi_is_scheduled(dev) && is_new_response(&q->desc[q->cidx], q)) {
+ if (likely(__netif_rx_schedule_prep(dev)))
+ __netif_rx_schedule(dev);
+ return 1;
+ }
+ return 0;
+}
+
+/*
+ * The MSI interrupt handler for the NAPI case (i.e., response queues serviced
+ * by NAPI polling). Handles data events from SGE response queues as well as
+ * error and other async events as they all use the same MSI vector. We use
+ * one SGE response queue per port in this mode and protect all response
+ * queues with queue 0's lock.
+ */
+irqreturn_t t3_intr_msi_napi(int irq, void *cookie)
+{
+ int new_packets;
+ struct adapter *adap = cookie;
+ struct sge_rspq *q = &adap->sge.qs[0].rspq;
+
+ spin_lock(&q->lock);
+
+ new_packets = rspq_check_napi(adap->sge.qs[0].netdev, q);
+ if (adap->params.nports == 2)
+ new_packets += rspq_check_napi(adap->sge.qs[1].netdev,
+ &adap->sge.qs[1].rspq);
+ if (!new_packets && t3_slow_intr_handler(adap) == 0)
+ q->unhandled_irqs++;
+
+ spin_unlock(&q->lock);
+ return IRQ_HANDLED;
+}
+
+/*
+ * A helper function that processes responses and issues GTS.
+ */
+static inline int process_responses_gts(struct adapter *adap,
+ struct sge_rspq *rq)
+{
+ int work;
+
+ work = process_responses(adap, rspq_to_qset(rq), -1);
+ t3_write_reg(adap, A_SG_GTS, V_RSPQ(rq->cntxt_id) |
+ V_NEWTIMER(rq->next_holdoff) | V_NEWINDEX(rq->cidx));
+ return work;
+}
+
+/*
+ * The legacy INTx interrupt handler. This needs to handle data events from
+ * SGE response queues as well as error and other async events as they all use
+ * the same interrupt pin. We use one SGE response queue per port in this mode
+ * and protect all response queues with queue 0's lock.
+ */
+static irqreturn_t t3_intr(int irq, void *cookie)
+{
+ int work_done, w0, w1;
+ struct adapter *adap = cookie;
+ struct sge_rspq *q0 = &adap->sge.qs[0].rspq;
+ struct sge_rspq *q1 = &adap->sge.qs[1].rspq;
+
+ spin_lock(&q0->lock);
+
+ w0 = is_new_response(&q0->desc[q0->cidx], q0);
+ w1 = adap->params.nports == 2 &&
+ is_new_response(&q1->desc[q1->cidx], q1);
+
+ if (likely(w0 | w1)) {
+ t3_write_reg(adap, A_PL_CLI, 0);
+ t3_read_reg(adap, A_PL_CLI); /* flush */
+
+ if (likely(w0))
+ process_responses_gts(adap, q0);
+
+ if (w1)
+ process_responses_gts(adap, q1);
+
+ work_done = w0 | w1;
+ } else
+ work_done = t3_slow_intr_handler(adap);
+
+ spin_unlock(&q0->lock);
+ return IRQ_RETVAL(work_done != 0);
+}
+
+/*
+ * Interrupt handler for legacy INTx interrupts for T3B-based cards.
+ * Handles data events from SGE response queues as well as error and other
+ * async events as they all use the same interrupt pin. We use one SGE
+ * response queue per port in this mode and protect all response queues with
+ * queue 0's lock.
+ */
+static irqreturn_t t3b_intr(int irq, void *cookie)
+{
+ u32 map;
+ struct adapter *adap = cookie;
+ struct sge_rspq *q0 = &adap->sge.qs[0].rspq;
+
+ t3_write_reg(adap, A_PL_CLI, 0);
+ map = t3_read_reg(adap, A_SG_DATA_INTR);
+
+ if (unlikely(!map)) /* shared interrupt, most likely */
+ return IRQ_NONE;
+
+ spin_lock(&q0->lock);
+
+ if (unlikely(map & F_ERRINTR))
+ t3_slow_intr_handler(adap);
+
+ if (likely(map & 1))
+ process_responses_gts(adap, q0);
+
+ if (map & 2)
+ process_responses_gts(adap, &adap->sge.qs[1].rspq);
+
+ spin_unlock(&q0->lock);
+ return IRQ_HANDLED;
+}
+
+/*
+ * NAPI interrupt handler for legacy INTx interrupts for T3B-based cards.
+ * Handles data events from SGE response queues as well as error and other
+ * async events as they all use the same interrupt pin. We use one SGE
+ * response queue per port in this mode and protect all response queues with
+ * queue 0's lock.
+ */
+static irqreturn_t t3b_intr_napi(int irq, void *cookie)
+{
+ u32 map;
+ struct net_device *dev;
+ struct adapter *adap = cookie;
+ struct sge_rspq *q0 = &adap->sge.qs[0].rspq;
+
+ t3_write_reg(adap, A_PL_CLI, 0);
+ map = t3_read_reg(adap, A_SG_DATA_INTR);
+
+ if (unlikely(!map)) /* shared interrupt, most likely */
+ return IRQ_NONE;
+
+ spin_lock(&q0->lock);
+
+ if (unlikely(map & F_ERRINTR))
+ t3_slow_intr_handler(adap);
+
+ if (likely(map & 1)) {
+ dev = adap->sge.qs[0].netdev;
+
+ BUG_ON(napi_is_scheduled(dev));
+ if (likely(__netif_rx_schedule_prep(dev)))
+ __netif_rx_schedule(dev);
+ }
+ if (map & 2) {
+ dev = adap->sge.qs[1].netdev;
+
+ BUG_ON(napi_is_scheduled(dev));
+ if (likely(__netif_rx_schedule_prep(dev)))
+ __netif_rx_schedule(dev);
+ }
+
+ spin_unlock(&q0->lock);
+ return IRQ_HANDLED;
+}
+
+/**
+ * t3_intr_handler - select the top-level interrupt handler
+ * @adap: the adapter
+ * @polling: whether using NAPI to service response queues
+ *
+ * Selects the top-level interrupt handler based on the type of interrupts
+ * (MSI-X, MSI, or legacy) and whether NAPI will be used to service the
+ * response queues.
+ */
+intr_handler_t t3_intr_handler(struct adapter *adap, int polling)
+{
+ if (adap->flags & USING_MSIX)
+ return polling ? t3_sge_intr_msix_napi : t3_sge_intr_msix;
+ if (adap->flags & USING_MSI)
+ return polling ? t3_intr_msi_napi : t3_intr_msi;
+ if (adap->params.rev > 0)
+ return polling ? t3b_intr_napi : t3b_intr;
+ return t3_intr;
+}
+
+/**
+ * t3_sge_err_intr_handler - SGE async event interrupt handler
+ * @adapter: the adapter
+ *
+ * Interrupt handler for SGE asynchronous (non-data) events.
+ */
+void t3_sge_err_intr_handler(struct adapter *adapter)
+{
+ unsigned int v, status = t3_read_reg(adapter, A_SG_INT_CAUSE);
+
+ if (status & F_RSPQCREDITOVERFOW)
+ CH_ALERT(adapter, "SGE response queue credit overflow\n");
+
+ if (status & F_RSPQDISABLED) {
+ v = t3_read_reg(adapter, A_SG_RSPQ_FL_STATUS);
+
+ CH_ALERT(adapter,
+ "packet delivered to disabled response queue "
+ "(0x%x)\n", (v >> S_RSPQ0DISABLED) & 0xff);
+ }
+
+ t3_write_reg(adapter, A_SG_INT_CAUSE, status);
+ if (status & (F_RSPQCREDITOVERFOW | F_RSPQDISABLED))
+ t3_fatal_err(adapter);
+}
+
+/**
+ * sge_timer_cb - perform periodic maintenance of an SGE qset
+ * @data: the SGE queue set to maintain
+ *
+ * Runs periodically from a timer to perform maintenance of an SGE queue
+ * set. It performs two tasks:
+ *
+ * a) Cleans up any completed Tx descriptors that may still be pending.
+ * Normal descriptor cleanup happens when new packets are added to a Tx
+ * queue so this timer is relatively infrequent and does any cleanup only
+ * if the Tx queue has not seen any new packets in a while. We make a
+ * best effort attempt to reclaim descriptors, in that we don't wait
+ * around if we cannot get a queue's lock (which most likely is because
+ * someone else is queueing new packets and so will also handle the clean
+ * up). Since control queues use immediate data exclusively we don't
+ * bother cleaning them up here.
+ *
+ * b) Replenishes Rx queues that have run out due to memory shortage.
+ * Normally new Rx buffers are added when existing ones are consumed but
+ * when out of memory a queue can become empty. We try to add only a few
+ * buffers here, the queue will be replenished fully as these new buffers
+ * are used up if memory shortage has subsided.
+ */
+static void sge_timer_cb(unsigned long data)
+{
+ spinlock_t *lock;
+ struct sge_qset *qs = (struct sge_qset *)data;
+ struct adapter *adap = qs->netdev->priv;
+
+ if (spin_trylock(&qs->txq[TXQ_ETH].lock)) {
+ reclaim_completed_tx(adap, &qs->txq[TXQ_ETH]);
+ spin_unlock(&qs->txq[TXQ_ETH].lock);
+ }
+ if (spin_trylock(&qs->txq[TXQ_OFLD].lock)) {
+ reclaim_completed_tx(adap, &qs->txq[TXQ_OFLD]);
+ spin_unlock(&qs->txq[TXQ_OFLD].lock);
+ }
+ lock = (adap->flags & USING_MSIX) ? &qs->rspq.lock :
+ &adap->sge.qs[0].rspq.lock;
+ if (spin_trylock_irq(lock)) {
+ if (!napi_is_scheduled(qs->netdev)) {
+ if (qs->fl[0].credits < qs->fl[0].size)
+ __refill_fl(adap, &qs->fl[0]);
+ if (qs->fl[1].credits < qs->fl[1].size)
+ __refill_fl(adap, &qs->fl[1]);
+ }
+ spin_unlock_irq(lock);
+ }
+ mod_timer(&qs->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
+}
+
+/**
+ * t3_update_qset_coalesce - update coalescing settings for a queue set
+ * @qs: the SGE queue set
+ * @p: new queue set parameters
+ *
+ * Update the coalescing settings for an SGE queue set. Nothing is done
+ * if the queue set is not initialized yet.
+ */
+void t3_update_qset_coalesce(struct sge_qset *qs, const struct qset_params *p)
+{
+ if (!qs->netdev)
+ return;
+
+ qs->rspq.holdoff_tmr = max(p->coalesce_usecs * 10, 1U);/* can't be 0 */
+ qs->rspq.polling = p->polling;
+ qs->netdev->poll = p->polling ? napi_rx_handler : ofld_poll;
+}
+
+/**
+ * t3_sge_alloc_qset - initialize an SGE queue set
+ * @adapter: the adapter
+ * @id: the queue set id
+ * @nports: how many Ethernet ports will be using this queue set
+ * @irq_vec_idx: the IRQ vector index for response queue interrupts
+ * @p: configuration parameters for this queue set
+ * @ntxq: number of Tx queues for the queue set
+ * @netdev: net device associated with this queue set
+ *
+ * Allocate resources and initialize an SGE queue set. A queue set
+ * comprises a response queue, two Rx free-buffer queues, and up to 3
+ * Tx queues. The Tx queues are assigned roles in the order Ethernet
+ * queue, offload queue, and control queue.
+ */
+int t3_sge_alloc_qset(struct adapter *adapter, unsigned int id, int nports,
+ int irq_vec_idx, const struct qset_params *p,
+ int ntxq, struct net_device *netdev)
+{
+ int i, ret = -ENOMEM;
+ struct sge_qset *q = &adapter->sge.qs[id];
+
+ init_qset_cntxt(q, id);
+ init_timer(&q->tx_reclaim_timer);
+ q->tx_reclaim_timer.data = (unsigned long)q;
+ q->tx_reclaim_timer.function = sge_timer_cb;
+
+ q->fl[0].desc = alloc_ring(adapter->pdev, p->fl_size,
+ sizeof(struct rx_desc),
+ sizeof(struct rx_sw_desc),
+ &q->fl[0].phys_addr, &q->fl[0].sdesc);
+ if (!q->fl[0].desc)
+ goto err;
+
+ q->fl[1].desc = alloc_ring(adapter->pdev, p->jumbo_size,
+ sizeof(struct rx_desc),
+ sizeof(struct rx_sw_desc),
+ &q->fl[1].phys_addr, &q->fl[1].sdesc);
+ if (!q->fl[1].desc)
+ goto err;
+
+ q->rspq.desc = alloc_ring(adapter->pdev, p->rspq_size,
+ sizeof(struct rsp_desc), 0,
+ &q->rspq.phys_addr, NULL);
+ if (!q->rspq.desc)
+ goto err;
+
+ for (i = 0; i < ntxq; ++i) {
+ /*
+ * The control queue always uses immediate data so does not
+ * need to keep track of any sk_buffs.
+ */
+ size_t sz = i == TXQ_CTRL ? 0 : sizeof(struct tx_sw_desc);
+
+ q->txq[i].desc = alloc_ring(adapter->pdev, p->txq_size[i],
+ sizeof(struct tx_desc), sz,
+ &q->txq[i].phys_addr,
+ &q->txq[i].sdesc);
+ if (!q->txq[i].desc)
+ goto err;
+
+ q->txq[i].gen = 1;
+ q->txq[i].size = p->txq_size[i];
+ spin_lock_init(&q->txq[i].lock);
+ skb_queue_head_init(&q->txq[i].sendq);
+ }
+
+ tasklet_init(&q->txq[TXQ_OFLD].qresume_tsk, restart_offloadq,
+ (unsigned long)q);
+ tasklet_init(&q->txq[TXQ_CTRL].qresume_tsk, restart_ctrlq,
+ (unsigned long)q);
+
+ q->fl[0].gen = q->fl[1].gen = 1;
+ q->fl[0].size = p->fl_size;
+ q->fl[1].size = p->jumbo_size;
+
+ q->rspq.gen = 1;
+ q->rspq.size = p->rspq_size;
+ spin_lock_init(&q->rspq.lock);
+
+ q->txq[TXQ_ETH].stop_thres = nports *
+ flits_to_desc(sgl_len(MAX_SKB_FRAGS + 1) + 3);
+
+ if (ntxq == 1) {
+ q->fl[0].buf_size = SGE_RX_SM_BUF_SIZE + 2 +
+ sizeof(struct cpl_rx_pkt);
+ q->fl[1].buf_size = MAX_FRAME_SIZE + 2 +
+ sizeof(struct cpl_rx_pkt);
+ } else {
+ q->fl[0].buf_size = SGE_RX_SM_BUF_SIZE +
+ sizeof(struct cpl_rx_data);
+ q->fl[1].buf_size = (16 * 1024) -
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+ }
+
+ spin_lock(&adapter->sge.reg_lock);
+
+ /* FL threshold comparison uses < */
+ ret = t3_sge_init_rspcntxt(adapter, q->rspq.cntxt_id, irq_vec_idx,
+ q->rspq.phys_addr, q->rspq.size,
+ q->fl[0].buf_size, 1, 0);
+ if (ret)
+ goto err_unlock;
+
+ for (i = 0; i < SGE_RXQ_PER_SET; ++i) {
+ ret = t3_sge_init_flcntxt(adapter, q->fl[i].cntxt_id, 0,
+ q->fl[i].phys_addr, q->fl[i].size,
+ q->fl[i].buf_size, p->cong_thres, 1,
+ 0);
+ if (ret)
+ goto err_unlock;
+ }
+
+ ret = t3_sge_init_ecntxt(adapter, q->txq[TXQ_ETH].cntxt_id, USE_GTS,
+ SGE_CNTXT_ETH, id, q->txq[TXQ_ETH].phys_addr,
+ q->txq[TXQ_ETH].size, q->txq[TXQ_ETH].token,
+ 1, 0);
+ if (ret)
+ goto err_unlock;
+
+ if (ntxq > 1) {
+ ret = t3_sge_init_ecntxt(adapter, q->txq[TXQ_OFLD].cntxt_id,
+ USE_GTS, SGE_CNTXT_OFLD, id,
+ q->txq[TXQ_OFLD].phys_addr,
+ q->txq[TXQ_OFLD].size, 0, 1, 0);
+ if (ret)
+ goto err_unlock;
+ }
+
+ if (ntxq > 2) {
+ ret = t3_sge_init_ecntxt(adapter, q->txq[TXQ_CTRL].cntxt_id, 0,
+ SGE_CNTXT_CTRL, id,
+ q->txq[TXQ_CTRL].phys_addr,
+ q->txq[TXQ_CTRL].size,
+ q->txq[TXQ_CTRL].token, 1, 0);
+ if (ret)
+ goto err_unlock;
+ }
+
+ spin_unlock(&adapter->sge.reg_lock);
+ q->netdev = netdev;
+ t3_update_qset_coalesce(q, p);
+
+ /*
+ * We use atalk_ptr as a backpointer to a qset. In case a device is
+ * associated with multiple queue sets only the first one sets
+ * atalk_ptr.
+ */
+ if (netdev->atalk_ptr == NULL)
+ netdev->atalk_ptr = q;
+
+ refill_fl(adapter, &q->fl[0], q->fl[0].size, GFP_KERNEL);
+ refill_fl(adapter, &q->fl[1], q->fl[1].size, GFP_KERNEL);
+ refill_rspq(adapter, &q->rspq, q->rspq.size - 1);
+
+ t3_write_reg(adapter, A_SG_GTS, V_RSPQ(q->rspq.cntxt_id) |
+ V_NEWTIMER(q->rspq.holdoff_tmr));
+
+ mod_timer(&q->tx_reclaim_timer, jiffies + TX_RECLAIM_PERIOD);
+ return 0;
+
+ err_unlock:
+ spin_unlock(&adapter->sge.reg_lock);
+ err:
+ t3_free_qset(adapter, q);
+ return ret;
+}
+
+/**
+ * t3_free_sge_resources - free SGE resources
+ * @adap: the adapter
+ *
+ * Frees resources used by the SGE queue sets.
+ */
+void t3_free_sge_resources(struct adapter *adap)
+{
+ int i;
+
+ for (i = 0; i < SGE_QSETS; ++i)
+ t3_free_qset(adap, &adap->sge.qs[i]);
+}
+
+/**
+ * t3_sge_start - enable SGE
+ * @adap: the adapter
+ *
+ * Enables the SGE for DMAs. This is the last step in starting packet
+ * transfers.
+ */
+void t3_sge_start(struct adapter *adap)
+{
+ t3_set_reg_field(adap, A_SG_CONTROL, F_GLOBALENABLE, F_GLOBALENABLE);
+}
+
+/**
+ * t3_sge_stop - disable SGE operation
+ * @adap: the adapter
+ *
+ * Disables the DMA engine. This can be called in emeregencies (e.g.,
+ * from error interrupts) or from normal process context. In the latter
+ * case it also disables any pending queue restart tasklets. Note that
+ * if it is called in interrupt context it cannot disable the restart
+ * tasklets as it cannot wait, however the tasklets will have no effect
+ * since the doorbells are disabled and the driver will call this again
+ * later from process context, at which time the tasklets will be stopped
+ * if they are still running.
+ */
+void t3_sge_stop(struct adapter *adap)
+{
+ t3_set_reg_field(adap, A_SG_CONTROL, F_GLOBALENABLE, 0);
+ if (!in_interrupt()) {
+ int i;
+
+ for (i = 0; i < SGE_QSETS; ++i) {
+ struct sge_qset *qs = &adap->sge.qs[i];
+
+ tasklet_kill(&qs->txq[TXQ_OFLD].qresume_tsk);
+ tasklet_kill(&qs->txq[TXQ_CTRL].qresume_tsk);
+ }
+ }
+}
+
+/**
+ * t3_sge_init - initialize SGE
+ * @adap: the adapter
+ * @p: the SGE parameters
+ *
+ * Performs SGE initialization needed every time after a chip reset.
+ * We do not initialize any of the queue sets here, instead the driver
+ * top-level must request those individually. We also do not enable DMA
+ * here, that should be done after the queues have been set up.
+ */
+void t3_sge_init(struct adapter *adap, struct sge_params *p)
+{
+ unsigned int ctrl, ups = ffs(pci_resource_len(adap->pdev, 2) >> 12);
+
+ ctrl = F_DROPPKT | V_PKTSHIFT(2) | F_FLMODE | F_AVOIDCQOVFL |
+ F_CQCRDTCTRL |
+ V_HOSTPAGESIZE(PAGE_SHIFT - 11) | F_BIGENDIANINGRESS |
+ V_USERSPACESIZE(ups ? ups - 1 : 0) | F_ISCSICOALESCING;
+#if SGE_NUM_GENBITS == 1
+ ctrl |= F_EGRGENCTRL;
+#endif
+ if (adap->params.rev > 0) {
+ if (!(adap->flags & (USING_MSIX | USING_MSI)))
+ ctrl |= F_ONEINTMULTQ | F_OPTONEINTMULTQ;
+ ctrl |= F_CQCRDTCTRL | F_AVOIDCQOVFL;
+ }
+ t3_write_reg(adap, A_SG_CONTROL, ctrl);
+ t3_write_reg(adap, A_SG_EGR_RCQ_DRB_THRSH, V_HIRCQDRBTHRSH(512) |
+ V_LORCQDRBTHRSH(512));
+ t3_write_reg(adap, A_SG_TIMER_TICK, core_ticks_per_usec(adap) / 10);
+ t3_write_reg(adap, A_SG_CMDQ_CREDIT_TH, V_THRESHOLD(32) |
+ V_TIMEOUT(100 * core_ticks_per_usec(adap)));
+ t3_write_reg(adap, A_SG_HI_DRB_HI_THRSH, 1000);
+ t3_write_reg(adap, A_SG_HI_DRB_LO_THRSH, 256);
+ t3_write_reg(adap, A_SG_LO_DRB_HI_THRSH, 1000);
+ t3_write_reg(adap, A_SG_LO_DRB_LO_THRSH, 256);
+ t3_write_reg(adap, A_SG_OCO_BASE, V_BASE1(0xfff));
+ t3_write_reg(adap, A_SG_DRB_PRI_THRESH, 63 * 1024);
+}
+
+/**
+ * t3_sge_prep - one-time SGE initialization
+ * @adap: the associated adapter
+ * @p: SGE parameters
+ *
+ * Performs one-time initialization of SGE SW state. Includes determining
+ * defaults for the assorted SGE parameters, which admins can change until
+ * they are used to initialize the SGE.
+ */
+void __devinit t3_sge_prep(struct adapter *adap, struct sge_params *p)
+{
+ int i;
+
+ p->max_pkt_size = (16 * 1024) - sizeof(struct cpl_rx_data) -
+ SKB_DATA_ALIGN(sizeof(struct skb_shared_info));
+
+ for (i = 0; i < SGE_QSETS; ++i) {
+ struct qset_params *q = p->qset + i;
+
+ q->polling = adap->params.rev > 0;
+ q->coalesce_usecs = 5;
+ q->rspq_size = 1024;
+ q->fl_size = 4096;
+ q->jumbo_size = 512;
+ q->txq_size[TXQ_ETH] = 1024;
+ q->txq_size[TXQ_OFLD] = 1024;
+ q->txq_size[TXQ_CTRL] = 256;
+ q->cong_thres = 0;
+ }
+
+ spin_lock_init(&adap->sge.reg_lock);
+}
+
+/**
+ * t3_get_desc - dump an SGE descriptor for debugging purposes
+ * @qs: the queue set
+ * @qnum: identifies the specific queue (0..2: Tx, 3:response, 4..5: Rx)
+ * @idx: the descriptor index in the queue
+ * @data: where to dump the descriptor contents
+ *
+ * Dumps the contents of a HW descriptor of an SGE queue. Returns the
+ * size of the descriptor.
+ */
+int t3_get_desc(const struct sge_qset *qs, unsigned int qnum, unsigned int idx,
+ unsigned char *data)
+{
+ if (qnum >= 6)
+ return -EINVAL;
+
+ if (qnum < 3) {
+ if (!qs->txq[qnum].desc || idx >= qs->txq[qnum].size)
+ return -EINVAL;
+ memcpy(data, &qs->txq[qnum].desc[idx], sizeof(struct tx_desc));
+ return sizeof(struct tx_desc);
+ }
+
+ if (qnum == 3) {
+ if (!qs->rspq.desc || idx >= qs->rspq.size)
+ return -EINVAL;
+ memcpy(data, &qs->rspq.desc[idx], sizeof(struct rsp_desc));
+ return sizeof(struct rsp_desc);
+ }
+
+ qnum -= 4;
+ if (!qs->fl[qnum].desc || idx >= qs->fl[qnum].size)
+ return -EINVAL;
+ memcpy(data, &qs->fl[qnum].desc[idx], sizeof(struct rx_desc));
+ return sizeof(struct rx_desc);
+}
diff --git a/drivers/net/cxgb3/sge_defs.h b/drivers/net/cxgb3/sge_defs.h
new file mode 100755
index 0000000..514869e
--- /dev/null
+++ b/drivers/net/cxgb3/sge_defs.h
@@ -0,0 +1,251 @@
+/*
+ * This file is automatically generated --- any changes will be lost.
+ */
+
+#ifndef _SGE_DEFS_H
+#define _SGE_DEFS_H
+
+#define S_EC_CREDITS 0
+#define M_EC_CREDITS 0x7FFF
+#define V_EC_CREDITS(x) ((x) << S_EC_CREDITS)
+#define G_EC_CREDITS(x) (((x) >> S_EC_CREDITS) & M_EC_CREDITS)
+
+#define S_EC_GTS 15
+#define V_EC_GTS(x) ((x) << S_EC_GTS)
+#define F_EC_GTS V_EC_GTS(1U)
+
+#define S_EC_INDEX 16
+#define M_EC_INDEX 0xFFFF
+#define V_EC_INDEX(x) ((x) << S_EC_INDEX)
+#define G_EC_INDEX(x) (((x) >> S_EC_INDEX) & M_EC_INDEX)
+
+#define S_EC_SIZE 0
+#define M_EC_SIZE 0xFFFF
+#define V_EC_SIZE(x) ((x) << S_EC_SIZE)
+#define G_EC_SIZE(x) (((x) >> S_EC_SIZE) & M_EC_SIZE)
+
+#define S_EC_BASE_LO 16
+#define M_EC_BASE_LO 0xFFFF
+#define V_EC_BASE_LO(x) ((x) << S_EC_BASE_LO)
+#define G_EC_BASE_LO(x) (((x) >> S_EC_BASE_LO) & M_EC_BASE_LO)
+
+#define S_EC_BASE_HI 0
+#define M_EC_BASE_HI 0xF
+#define V_EC_BASE_HI(x) ((x) << S_EC_BASE_HI)
+#define G_EC_BASE_HI(x) (((x) >> S_EC_BASE_HI) & M_EC_BASE_HI)
+
+#define S_EC_RESPQ 4
+#define M_EC_RESPQ 0x7
+#define V_EC_RESPQ(x) ((x) << S_EC_RESPQ)
+#define G_EC_RESPQ(x) (((x) >> S_EC_RESPQ) & M_EC_RESPQ)
+
+#define S_EC_TYPE 7
+#define M_EC_TYPE 0x7
+#define V_EC_TYPE(x) ((x) << S_EC_TYPE)
+#define G_EC_TYPE(x) (((x) >> S_EC_TYPE) & M_EC_TYPE)
+
+#define S_EC_GEN 10
+#define V_EC_GEN(x) ((x) << S_EC_GEN)
+#define F_EC_GEN V_EC_GEN(1U)
+
+#define S_EC_UP_TOKEN 11
+#define M_EC_UP_TOKEN 0xFFFFF
+#define V_EC_UP_TOKEN(x) ((x) << S_EC_UP_TOKEN)
+#define G_EC_UP_TOKEN(x) (((x) >> S_EC_UP_TOKEN) & M_EC_UP_TOKEN)
+
+#define S_EC_VALID 31
+#define V_EC_VALID(x) ((x) << S_EC_VALID)
+#define F_EC_VALID V_EC_VALID(1U)
+
+#define S_RQ_MSI_VEC 20
+#define M_RQ_MSI_VEC 0x3F
+#define V_RQ_MSI_VEC(x) ((x) << S_RQ_MSI_VEC)
+#define G_RQ_MSI_VEC(x) (((x) >> S_RQ_MSI_VEC) & M_RQ_MSI_VEC)
+
+#define S_RQ_INTR_EN 26
+#define V_RQ_INTR_EN(x) ((x) << S_RQ_INTR_EN)
+#define F_RQ_INTR_EN V_RQ_INTR_EN(1U)
+
+#define S_RQ_GEN 28
+#define V_RQ_GEN(x) ((x) << S_RQ_GEN)
+#define F_RQ_GEN V_RQ_GEN(1U)
+
+#define S_CQ_INDEX 0
+#define M_CQ_INDEX 0xFFFF
+#define V_CQ_INDEX(x) ((x) << S_CQ_INDEX)
+#define G_CQ_INDEX(x) (((x) >> S_CQ_INDEX) & M_CQ_INDEX)
+
+#define S_CQ_SIZE 16
+#define M_CQ_SIZE 0xFFFF
+#define V_CQ_SIZE(x) ((x) << S_CQ_SIZE)
+#define G_CQ_SIZE(x) (((x) >> S_CQ_SIZE) & M_CQ_SIZE)
+
+#define S_CQ_BASE_HI 0
+#define M_CQ_BASE_HI 0xFFFFF
+#define V_CQ_BASE_HI(x) ((x) << S_CQ_BASE_HI)
+#define G_CQ_BASE_HI(x) (((x) >> S_CQ_BASE_HI) & M_CQ_BASE_HI)
+
+#define S_CQ_RSPQ 20
+#define M_CQ_RSPQ 0x3F
+#define V_CQ_RSPQ(x) ((x) << S_CQ_RSPQ)
+#define G_CQ_RSPQ(x) (((x) >> S_CQ_RSPQ) & M_CQ_RSPQ)
+
+#define S_CQ_ASYNC_NOTIF 26
+#define V_CQ_ASYNC_NOTIF(x) ((x) << S_CQ_ASYNC_NOTIF)
+#define F_CQ_ASYNC_NOTIF V_CQ_ASYNC_NOTIF(1U)
+
+#define S_CQ_ARMED 27
+#define V_CQ_ARMED(x) ((x) << S_CQ_ARMED)
+#define F_CQ_ARMED V_CQ_ARMED(1U)
+
+#define S_CQ_ASYNC_NOTIF_SOL 28
+#define V_CQ_ASYNC_NOTIF_SOL(x) ((x) << S_CQ_ASYNC_NOTIF_SOL)
+#define F_CQ_ASYNC_NOTIF_SOL V_CQ_ASYNC_NOTIF_SOL(1U)
+
+#define S_CQ_GEN 29
+#define V_CQ_GEN(x) ((x) << S_CQ_GEN)
+#define F_CQ_GEN V_CQ_GEN(1U)
+
+#define S_CQ_OVERFLOW_MODE 31
+#define V_CQ_OVERFLOW_MODE(x) ((x) << S_CQ_OVERFLOW_MODE)
+#define F_CQ_OVERFLOW_MODE V_CQ_OVERFLOW_MODE(1U)
+
+#define S_CQ_CREDITS 0
+#define M_CQ_CREDITS 0xFFFF
+#define V_CQ_CREDITS(x) ((x) << S_CQ_CREDITS)
+#define G_CQ_CREDITS(x) (((x) >> S_CQ_CREDITS) & M_CQ_CREDITS)
+
+#define S_CQ_CREDIT_THRES 16
+#define M_CQ_CREDIT_THRES 0x1FFF
+#define V_CQ_CREDIT_THRES(x) ((x) << S_CQ_CREDIT_THRES)
+#define G_CQ_CREDIT_THRES(x) (((x) >> S_CQ_CREDIT_THRES) & M_CQ_CREDIT_THRES)
+
+#define S_FL_BASE_HI 0
+#define M_FL_BASE_HI 0xFFFFF
+#define V_FL_BASE_HI(x) ((x) << S_FL_BASE_HI)
+#define G_FL_BASE_HI(x) (((x) >> S_FL_BASE_HI) & M_FL_BASE_HI)
+
+#define S_FL_INDEX_LO 20
+#define M_FL_INDEX_LO 0xFFF
+#define V_FL_INDEX_LO(x) ((x) << S_FL_INDEX_LO)
+#define G_FL_INDEX_LO(x) (((x) >> S_FL_INDEX_LO) & M_FL_INDEX_LO)
+
+#define S_FL_INDEX_HI 0
+#define M_FL_INDEX_HI 0xF
+#define V_FL_INDEX_HI(x) ((x) << S_FL_INDEX_HI)
+#define G_FL_INDEX_HI(x) (((x) >> S_FL_INDEX_HI) & M_FL_INDEX_HI)
+
+#define S_FL_SIZE 4
+#define M_FL_SIZE 0xFFFF
+#define V_FL_SIZE(x) ((x) << S_FL_SIZE)
+#define G_FL_SIZE(x) (((x) >> S_FL_SIZE) & M_FL_SIZE)
+
+#define S_FL_GEN 20
+#define V_FL_GEN(x) ((x) << S_FL_GEN)
+#define F_FL_GEN V_FL_GEN(1U)
+
+#define S_FL_ENTRY_SIZE_LO 21
+#define M_FL_ENTRY_SIZE_LO 0x7FF
+#define V_FL_ENTRY_SIZE_LO(x) ((x) << S_FL_ENTRY_SIZE_LO)
+#define G_FL_ENTRY_SIZE_LO(x) (((x) >> S_FL_ENTRY_SIZE_LO) & M_FL_ENTRY_SIZE_LO)
+
+#define S_FL_ENTRY_SIZE_HI 0
+#define M_FL_ENTRY_SIZE_HI 0x1FFFFF
+#define V_FL_ENTRY_SIZE_HI(x) ((x) << S_FL_ENTRY_SIZE_HI)
+#define G_FL_ENTRY_SIZE_HI(x) (((x) >> S_FL_ENTRY_SIZE_HI) & M_FL_ENTRY_SIZE_HI)
+
+#define S_FL_CONG_THRES 21
+#define M_FL_CONG_THRES 0x3FF
+#define V_FL_CONG_THRES(x) ((x) << S_FL_CONG_THRES)
+#define G_FL_CONG_THRES(x) (((x) >> S_FL_CONG_THRES) & M_FL_CONG_THRES)
+
+#define S_FL_GTS 31
+#define V_FL_GTS(x) ((x) << S_FL_GTS)
+#define F_FL_GTS V_FL_GTS(1U)
+
+#define S_FLD_GEN1 31
+#define V_FLD_GEN1(x) ((x) << S_FLD_GEN1)
+#define F_FLD_GEN1 V_FLD_GEN1(1U)
+
+#define S_FLD_GEN2 0
+#define V_FLD_GEN2(x) ((x) << S_FLD_GEN2)
+#define F_FLD_GEN2 V_FLD_GEN2(1U)
+
+#define S_RSPD_TXQ1_CR 0
+#define M_RSPD_TXQ1_CR 0x7F
+#define V_RSPD_TXQ1_CR(x) ((x) << S_RSPD_TXQ1_CR)
+#define G_RSPD_TXQ1_CR(x) (((x) >> S_RSPD_TXQ1_CR) & M_RSPD_TXQ1_CR)
+
+#define S_RSPD_TXQ1_GTS 7
+#define V_RSPD_TXQ1_GTS(x) ((x) << S_RSPD_TXQ1_GTS)
+#define F_RSPD_TXQ1_GTS V_RSPD_TXQ1_GTS(1U)
+
+#define S_RSPD_TXQ2_CR 8
+#define M_RSPD_TXQ2_CR 0x7F
+#define V_RSPD_TXQ2_CR(x) ((x) << S_RSPD_TXQ2_CR)
+#define G_RSPD_TXQ2_CR(x) (((x) >> S_RSPD_TXQ2_CR) & M_RSPD_TXQ2_CR)
+
+#define S_RSPD_TXQ2_GTS 15
+#define V_RSPD_TXQ2_GTS(x) ((x) << S_RSPD_TXQ2_GTS)
+#define F_RSPD_TXQ2_GTS V_RSPD_TXQ2_GTS(1U)
+
+#define S_RSPD_TXQ0_CR 16
+#define M_RSPD_TXQ0_CR 0x7F
+#define V_RSPD_TXQ0_CR(x) ((x) << S_RSPD_TXQ0_CR)
+#define G_RSPD_TXQ0_CR(x) (((x) >> S_RSPD_TXQ0_CR) & M_RSPD_TXQ0_CR)
+
+#define S_RSPD_TXQ0_GTS 23
+#define V_RSPD_TXQ0_GTS(x) ((x) << S_RSPD_TXQ0_GTS)
+#define F_RSPD_TXQ0_GTS V_RSPD_TXQ0_GTS(1U)
+
+#define S_RSPD_EOP 24
+#define V_RSPD_EOP(x) ((x) << S_RSPD_EOP)
+#define F_RSPD_EOP V_RSPD_EOP(1U)
+
+#define S_RSPD_SOP 25
+#define V_RSPD_SOP(x) ((x) << S_RSPD_SOP)
+#define F_RSPD_SOP V_RSPD_SOP(1U)
+
+#define S_RSPD_ASYNC_NOTIF 26
+#define V_RSPD_ASYNC_NOTIF(x) ((x) << S_RSPD_ASYNC_NOTIF)
+#define F_RSPD_ASYNC_NOTIF V_RSPD_ASYNC_NOTIF(1U)
+
+#define S_RSPD_FL0_GTS 27
+#define V_RSPD_FL0_GTS(x) ((x) << S_RSPD_FL0_GTS)
+#define F_RSPD_FL0_GTS V_RSPD_FL0_GTS(1U)
+
+#define S_RSPD_FL1_GTS 28
+#define V_RSPD_FL1_GTS(x) ((x) << S_RSPD_FL1_GTS)
+#define F_RSPD_FL1_GTS V_RSPD_FL1_GTS(1U)
+
+#define S_RSPD_IMM_DATA_VALID 29
+#define V_RSPD_IMM_DATA_VALID(x) ((x) << S_RSPD_IMM_DATA_VALID)
+#define F_RSPD_IMM_DATA_VALID V_RSPD_IMM_DATA_VALID(1U)
+
+#define S_RSPD_OFFLOAD 30
+#define V_RSPD_OFFLOAD(x) ((x) << S_RSPD_OFFLOAD)
+#define F_RSPD_OFFLOAD V_RSPD_OFFLOAD(1U)
+
+#define S_RSPD_GEN1 31
+#define V_RSPD_GEN1(x) ((x) << S_RSPD_GEN1)
+#define F_RSPD_GEN1 V_RSPD_GEN1(1U)
+
+#define S_RSPD_LEN 0
+#define M_RSPD_LEN 0x7FFFFFFF
+#define V_RSPD_LEN(x) ((x) << S_RSPD_LEN)
+#define G_RSPD_LEN(x) (((x) >> S_RSPD_LEN) & M_RSPD_LEN)
+
+#define S_RSPD_FLQ 31
+#define V_RSPD_FLQ(x) ((x) << S_RSPD_FLQ)
+#define F_RSPD_FLQ V_RSPD_FLQ(1U)
+
+#define S_RSPD_GEN2 0
+#define V_RSPD_GEN2(x) ((x) << S_RSPD_GEN2)
+#define F_RSPD_GEN2 V_RSPD_GEN2(1U)
+
+#define S_RSPD_INR_VEC 1
+#define M_RSPD_INR_VEC 0x7F
+#define V_RSPD_INR_VEC(x) ((x) << S_RSPD_INR_VEC)
+#define G_RSPD_INR_VEC(x) (((x) >> S_RSPD_INR_VEC) & M_RSPD_INR_VEC)
+
+#endif /* _SGE_DEFS_H */