diff options
Diffstat (limited to 'drivers/net/cxgb3/sge.c')
| -rw-r--r-- | drivers/net/cxgb3/sge.c | 2702 |
1 files changed, 2702 insertions, 0 deletions
diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c new file mode 100644 index 000000000000..6c77f4bab62f --- /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); +} |
