From 5e68b772e6efd189d6aca76f6872fb75d51ace60 Mon Sep 17 00:00:00 2001 From: Divy Le Ray Date: Thu, 26 Mar 2009 16:39:29 +0000 Subject: [PATCH] cxgb3: map entire Rx page, feed map+offset to Rx ring. DMA mapping can be expensive in the presence of iommus. Reduce the Rx iommu activity by mapping an entire page, and provide the H/W the mapped address + offset of the current page chunk. Reserve bits at the end of the page to track mapping references, so the page can be unmapped. Signed-off-by: Divy Le Ray Signed-off-by: David S. Miller --- drivers/net/cxgb3/adapter.h | 3 + drivers/net/cxgb3/sge.c | 138 +++++++++++++++++++++++++++--------- 2 files changed, 106 insertions(+), 35 deletions(-) mode change 100755 => 100644 drivers/net/cxgb3/sge.c diff --git a/drivers/net/cxgb3/adapter.h b/drivers/net/cxgb3/adapter.h index 2cf6c9299f22..714df2b675e6 100644 --- a/drivers/net/cxgb3/adapter.h +++ b/drivers/net/cxgb3/adapter.h @@ -85,6 +85,8 @@ struct fl_pg_chunk { struct page *page; void *va; unsigned int offset; + u64 *p_cnt; + DECLARE_PCI_UNMAP_ADDR(mapping); }; struct rx_desc; @@ -101,6 +103,7 @@ struct sge_fl { /* SGE per free-buffer list state */ struct fl_pg_chunk pg_chunk;/* page chunk cache */ unsigned int use_pages; /* whether FL uses pages or sk_buffs */ unsigned int order; /* order of page allocations */ + unsigned int alloc_size; /* size of allocated buffer */ struct rx_desc *desc; /* address of HW Rx descriptor ring */ struct rx_sw_desc *sdesc; /* address of SW Rx descriptor ring */ dma_addr_t phys_addr; /* physical address of HW ring start */ diff --git a/drivers/net/cxgb3/sge.c b/drivers/net/cxgb3/sge.c old mode 100755 new mode 100644 index 54667f0dde94..26d3587f3399 --- a/drivers/net/cxgb3/sge.c +++ b/drivers/net/cxgb3/sge.c @@ -50,6 +50,7 @@ #define SGE_RX_COPY_THRES 256 #define SGE_RX_PULL_LEN 128 +#define SGE_PG_RSVD SMP_CACHE_BYTES /* * Page chunk size for FL0 buffers if FL0 is to be populated with page chunks. * It must be a divisor of PAGE_SIZE. If set to 0 FL0 will use sk_buffs @@ -57,8 +58,10 @@ */ #define FL0_PG_CHUNK_SIZE 2048 #define FL0_PG_ORDER 0 +#define FL0_PG_ALLOC_SIZE (PAGE_SIZE << FL0_PG_ORDER) #define FL1_PG_CHUNK_SIZE (PAGE_SIZE > 8192 ? 16384 : 8192) #define FL1_PG_ORDER (PAGE_SIZE > 8192 ? 0 : 1) +#define FL1_PG_ALLOC_SIZE (PAGE_SIZE << FL1_PG_ORDER) #define SGE_RX_DROP_THRES 16 #define RX_RECLAIM_PERIOD (HZ/4) @@ -345,13 +348,21 @@ static inline int should_restart_tx(const struct sge_txq *q) return q->in_use - r < (q->size >> 1); } -static void clear_rx_desc(const struct sge_fl *q, struct rx_sw_desc *d) +static void clear_rx_desc(struct pci_dev *pdev, const struct sge_fl *q, + struct rx_sw_desc *d) { - if (q->use_pages) { - if (d->pg_chunk.page) - put_page(d->pg_chunk.page); + if (q->use_pages && d->pg_chunk.page) { + (*d->pg_chunk.p_cnt)--; + if (!*d->pg_chunk.p_cnt) + pci_unmap_page(pdev, + pci_unmap_addr(&d->pg_chunk, mapping), + q->alloc_size, PCI_DMA_FROMDEVICE); + + put_page(d->pg_chunk.page); d->pg_chunk.page = NULL; } else { + pci_unmap_single(pdev, pci_unmap_addr(d, dma_addr), + q->buf_size, PCI_DMA_FROMDEVICE); kfree_skb(d->skb); d->skb = NULL; } @@ -372,9 +383,8 @@ static void free_rx_bufs(struct pci_dev *pdev, struct sge_fl *q) 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); - clear_rx_desc(q, d); + + clear_rx_desc(pdev, q, d); if (++cidx == q->size) cidx = 0; } @@ -417,18 +427,39 @@ static inline int add_one_rx_buf(void *va, unsigned int len, return 0; } -static int alloc_pg_chunk(struct sge_fl *q, struct rx_sw_desc *sd, gfp_t gfp, +static inline int add_one_rx_chunk(dma_addr_t mapping, struct rx_desc *d, + unsigned int gen) +{ + 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)); + return 0; +} + +static int alloc_pg_chunk(struct adapter *adapter, struct sge_fl *q, + struct rx_sw_desc *sd, gfp_t gfp, unsigned int order) { if (!q->pg_chunk.page) { + dma_addr_t mapping; + q->pg_chunk.page = alloc_pages(gfp, order); if (unlikely(!q->pg_chunk.page)) return -ENOMEM; q->pg_chunk.va = page_address(q->pg_chunk.page); + q->pg_chunk.p_cnt = q->pg_chunk.va + (PAGE_SIZE << order) - + SGE_PG_RSVD; q->pg_chunk.offset = 0; + mapping = pci_map_page(adapter->pdev, q->pg_chunk.page, + 0, q->alloc_size, PCI_DMA_FROMDEVICE); + pci_unmap_addr_set(&q->pg_chunk, mapping, mapping); } sd->pg_chunk = q->pg_chunk; + prefetch(sd->pg_chunk.p_cnt); + q->pg_chunk.offset += q->buf_size; if (q->pg_chunk.offset == (PAGE_SIZE << order)) q->pg_chunk.page = NULL; @@ -436,6 +467,12 @@ static int alloc_pg_chunk(struct sge_fl *q, struct rx_sw_desc *sd, gfp_t gfp, q->pg_chunk.va += q->buf_size; get_page(q->pg_chunk.page); } + + if (sd->pg_chunk.offset == 0) + *sd->pg_chunk.p_cnt = 1; + else + *sd->pg_chunk.p_cnt += 1; + return 0; } @@ -460,35 +497,43 @@ static inline void ring_fl_db(struct adapter *adap, struct sge_fl *q) */ static int refill_fl(struct adapter *adap, struct sge_fl *q, int n, gfp_t gfp) { - void *buf_start; struct rx_sw_desc *sd = &q->sdesc[q->pidx]; struct rx_desc *d = &q->desc[q->pidx]; unsigned int count = 0; while (n--) { + dma_addr_t mapping; int err; if (q->use_pages) { - if (unlikely(alloc_pg_chunk(q, sd, gfp, q->order))) { + if (unlikely(alloc_pg_chunk(adap, q, sd, gfp, + q->order))) { nomem: q->alloc_failed++; break; } - buf_start = sd->pg_chunk.va; + mapping = pci_unmap_addr(&sd->pg_chunk, mapping) + + sd->pg_chunk.offset; + pci_unmap_addr_set(sd, dma_addr, mapping); + + add_one_rx_chunk(mapping, d, q->gen); + pci_dma_sync_single_for_device(adap->pdev, mapping, + q->buf_size - SGE_PG_RSVD, + PCI_DMA_FROMDEVICE); } else { - struct sk_buff *skb = alloc_skb(q->buf_size, gfp); + void *buf_start; + struct sk_buff *skb = alloc_skb(q->buf_size, gfp); if (!skb) goto nomem; sd->skb = skb; buf_start = skb->data; - } - - err = add_one_rx_buf(buf_start, q->buf_size, d, sd, q->gen, - adap->pdev); - if (unlikely(err)) { - clear_rx_desc(q, sd); - break; + err = add_one_rx_buf(buf_start, q->buf_size, d, sd, + q->gen, adap->pdev); + if (unlikely(err)) { + clear_rx_desc(adap->pdev, q, sd); + break; + } } d++; @@ -795,19 +840,19 @@ static struct sk_buff *get_packet_pg(struct adapter *adap, struct sge_fl *fl, struct sk_buff *newskb, *skb; struct rx_sw_desc *sd = &fl->sdesc[fl->cidx]; - newskb = skb = q->pg_skb; + dma_addr_t dma_addr = pci_unmap_addr(sd, dma_addr); + newskb = skb = q->pg_skb; if (!skb && (len <= SGE_RX_COPY_THRES)) { newskb = alloc_skb(len, GFP_ATOMIC); if (likely(newskb != NULL)) { __skb_put(newskb, len); - pci_dma_sync_single_for_cpu(adap->pdev, - pci_unmap_addr(sd, dma_addr), len, + pci_dma_sync_single_for_cpu(adap->pdev, dma_addr, len, PCI_DMA_FROMDEVICE); memcpy(newskb->data, sd->pg_chunk.va, len); - pci_dma_sync_single_for_device(adap->pdev, - pci_unmap_addr(sd, dma_addr), len, - PCI_DMA_FROMDEVICE); + pci_dma_sync_single_for_device(adap->pdev, dma_addr, + len, + PCI_DMA_FROMDEVICE); } else if (!drop_thres) return NULL; recycle: @@ -820,16 +865,25 @@ recycle: if (unlikely(q->rx_recycle_buf || (!skb && fl->credits <= drop_thres))) goto recycle; + prefetch(sd->pg_chunk.p_cnt); + if (!skb) newskb = alloc_skb(SGE_RX_PULL_LEN, GFP_ATOMIC); + if (unlikely(!newskb)) { if (!drop_thres) return NULL; goto recycle; } - pci_unmap_single(adap->pdev, pci_unmap_addr(sd, dma_addr), - fl->buf_size, PCI_DMA_FROMDEVICE); + pci_dma_sync_single_for_cpu(adap->pdev, dma_addr, len, + PCI_DMA_FROMDEVICE); + (*sd->pg_chunk.p_cnt)--; + if (!*sd->pg_chunk.p_cnt) + pci_unmap_page(adap->pdev, + pci_unmap_addr(&sd->pg_chunk, mapping), + fl->alloc_size, + PCI_DMA_FROMDEVICE); if (!skb) { __skb_put(newskb, SGE_RX_PULL_LEN); memcpy(newskb->data, sd->pg_chunk.va, SGE_RX_PULL_LEN); @@ -1958,8 +2012,8 @@ static void rx_eth(struct adapter *adap, struct sge_rspq *rq, skb_pull(skb, sizeof(*p) + pad); skb->protocol = eth_type_trans(skb, adap->port[p->iff]); pi = netdev_priv(skb->dev); - if ((pi->rx_offload & T3_RX_CSUM) && p->csum_valid && p->csum == htons(0xffff) && - !p->fragment) { + if ((pi->rx_offload & T3_RX_CSUM) && p->csum_valid && + p->csum == htons(0xffff) && !p->fragment) { qs->port_stats[SGE_PSTAT_RX_CSUM_GOOD]++; skb->ip_summed = CHECKSUM_UNNECESSARY; } else @@ -2034,10 +2088,19 @@ static void lro_add_page(struct adapter *adap, struct sge_qset *qs, fl->credits--; len -= offset; - pci_unmap_single(adap->pdev, pci_unmap_addr(sd, dma_addr), - fl->buf_size, PCI_DMA_FROMDEVICE); + pci_dma_sync_single_for_cpu(adap->pdev, + pci_unmap_addr(sd, dma_addr), + fl->buf_size - SGE_PG_RSVD, + PCI_DMA_FROMDEVICE); + + (*sd->pg_chunk.p_cnt)--; + if (!*sd->pg_chunk.p_cnt) + pci_unmap_page(adap->pdev, + pci_unmap_addr(&sd->pg_chunk, mapping), + fl->alloc_size, + PCI_DMA_FROMDEVICE); - prefetch(&qs->lro_frag_tbl); + prefetch(qs->lro_va); rx_frag += nr_frags; rx_frag->page = sd->pg_chunk.page; @@ -2047,6 +2110,7 @@ static void lro_add_page(struct adapter *adap, struct sge_qset *qs, qs->lro_frag_tbl.nr_frags++; qs->lro_frag_tbl.len = frag_len; + if (!complete) return; @@ -2236,6 +2300,8 @@ no_mem: if (fl->use_pages) { void *addr = fl->sdesc[fl->cidx].pg_chunk.va; + prefetch(&qs->lro_frag_tbl); + prefetch(addr); #if L1_CACHE_BYTES < 128 prefetch(addr + L1_CACHE_BYTES); @@ -2972,21 +3038,23 @@ int t3_sge_alloc_qset(struct adapter *adapter, unsigned int id, int nports, q->fl[1].use_pages = FL1_PG_CHUNK_SIZE > 0; q->fl[0].order = FL0_PG_ORDER; q->fl[1].order = FL1_PG_ORDER; + q->fl[0].alloc_size = FL0_PG_ALLOC_SIZE; + q->fl[1].alloc_size = FL1_PG_ALLOC_SIZE; spin_lock_irq(&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); + q->fl[0].buf_size - SGE_PG_RSVD, 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); + q->fl[i].buf_size - SGE_PG_RSVD, + p->cong_thres, 1, 0); if (ret) goto err_unlock; } -- 2.20.1