static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) { unsigned short id; struct netfront_info *np = netdev_priv(dev); struct xen_netif_tx_request *tx; struct xen_netif_extra_info *extra; char *data = skb->data; RING_IDX i; grant_ref_t ref; unsigned long mfn; int notify; int frags = skb_shinfo(skb)->nr_frags; unsigned int offset = offset_in_page(data); unsigned int len = skb_headlen(skb); frags += (offset + len + PAGE_SIZE - 1) / PAGE_SIZE; if (unlikely(frags > MAX_SKB_FRAGS + 1)) { printk(KERN_ALERT "xennet: skb rides the rocket: %d frags\n", frags); dump_stack(); goto drop; } spin_lock_irq(&np->tx_lock); if (unlikely(!netif_carrier_ok(dev) || (frags > 1 && !xennet_can_sg(dev)) || netif_needs_gso(dev, skb))) { spin_unlock_irq(&np->tx_lock); goto drop; } i = np->tx.req_prod_pvt; id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); np->tx_skbs[id].skb = skb; tx = RING_GET_REQUEST(&np->tx, i); tx->id = id; ref = gnttab_claim_grant_reference(&np->gref_tx_head); BUG_ON((signed short)ref < 0); mfn = virt_to_mfn(data); gnttab_grant_foreign_access_ref( ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = len; extra = NULL; tx->flags = 0; if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */ tx->flags |= NETTXF_csum_blank | NETTXF_data_validated; else if (skb->ip_summed == CHECKSUM_UNNECESSARY) /* remote but checksummed. */ tx->flags |= NETTXF_data_validated; if (skb_shinfo(skb)->gso_size) { struct xen_netif_extra_info *gso; gso = (struct xen_netif_extra_info *) RING_GET_REQUEST(&np->tx, ++i); if (extra) extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE; else tx->flags |= NETTXF_extra_info; gso->u.gso.size = skb_shinfo(skb)->gso_size; gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4; gso->u.gso.pad = 0; gso->u.gso.features = 0; gso->type = XEN_NETIF_EXTRA_TYPE_GSO; gso->flags = 0; extra = gso; } np->tx.req_prod_pvt = i + 1; xennet_make_frags(skb, dev, tx); tx->size = skb->len; RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify); if (notify) notify_remote_via_irq(np->netdev->irq); dev->stats.tx_bytes += skb->len; dev->stats.tx_packets++; /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ xennet_tx_buf_gc(dev); if (!netfront_tx_slot_available(np)) netif_stop_queue(dev); spin_unlock_irq(&np->tx_lock); return 0; drop: dev->stats.tx_dropped++; dev_kfree_skb(skb); return 0; }
static void xennet_alloc_rx_buffers(struct net_device *dev) { unsigned short id; struct netfront_info *np = netdev_priv(dev); struct sk_buff *skb; struct page *page; int i, batch_target, notify; RING_IDX req_prod = np->rx.req_prod_pvt; grant_ref_t ref; unsigned long pfn; void *vaddr; struct xen_netif_rx_request *req; if (unlikely(!netif_carrier_ok(dev))) return; /* * Allocate skbuffs greedily, even though we batch updates to the * receive ring. This creates a less bursty demand on the memory * allocator, so should reduce the chance of failed allocation requests * both for ourself and for other kernel subsystems. */ batch_target = np->rx_target - (req_prod - np->rx.rsp_cons); for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) { skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD, GFP_ATOMIC | __GFP_NOWARN); if (unlikely(!skb)) goto no_skb; page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); if (!page) { kfree_skb(skb); no_skb: /* Any skbuffs queued for refill? Force them out. */ if (i != 0) goto refill; /* Could not allocate any skbuffs. Try again later. */ mod_timer(&np->rx_refill_timer, jiffies + (HZ/10)); break; } skb_shinfo(skb)->frags[0].page = page; skb_shinfo(skb)->nr_frags = 1; __skb_queue_tail(&np->rx_batch, skb); } /* Is the batch large enough to be worthwhile? */ if (i < (np->rx_target/2)) { if (req_prod > np->rx.sring->req_prod) goto push; return; } /* Adjust our fill target if we risked running out of buffers. */ if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) && ((np->rx_target *= 2) > np->rx_max_target)) np->rx_target = np->rx_max_target; refill: for (i = 0; ; i++) { skb = __skb_dequeue(&np->rx_batch); if (skb == NULL) break; skb->dev = dev; id = xennet_rxidx(req_prod + i); BUG_ON(np->rx_skbs[id]); np->rx_skbs[id] = skb; ref = gnttab_claim_grant_reference(&np->gref_rx_head); BUG_ON((signed short)ref < 0); np->grant_rx_ref[id] = ref; pfn = page_to_pfn(skb_shinfo(skb)->frags[0].page); vaddr = page_address(skb_shinfo(skb)->frags[0].page); req = RING_GET_REQUEST(&np->rx, req_prod + i); gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, pfn_to_mfn(pfn), 0); req->id = id; req->gref = ref; } wmb(); /* barrier so backend seens requests */ /* Above is a suitable barrier to ensure backend will see requests. */ np->rx.req_prod_pvt = req_prod + i; push: RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify); if (notify) notify_remote_via_irq(np->netdev->irq); }
static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, struct xen_netif_tx_request *tx) { struct netfront_info *np = netdev_priv(dev); char *data = skb->data; unsigned long mfn; RING_IDX prod = np->tx.req_prod_pvt; int frags = skb_shinfo(skb)->nr_frags; unsigned int offset = offset_in_page(data); unsigned int len = skb_headlen(skb); unsigned int id; grant_ref_t ref; int i; /* While the header overlaps a page boundary (including being larger than a page), split it it into page-sized chunks. */ while (len > PAGE_SIZE - offset) { tx->size = PAGE_SIZE - offset; tx->flags |= NETTXF_more_data; len -= tx->size; data += tx->size; offset = 0; id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); np->tx_skbs[id].skb = skb_get(skb); tx = RING_GET_REQUEST(&np->tx, prod++); tx->id = id; ref = gnttab_claim_grant_reference(&np->gref_tx_head); BUG_ON((signed short)ref < 0); mfn = virt_to_mfn(data); gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = len; tx->flags = 0; } /* Grant backend access to each skb fragment page. */ for (i = 0; i < frags; i++) { skb_frag_t *frag = skb_shinfo(skb)->frags + i; tx->flags |= NETTXF_more_data; id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); np->tx_skbs[id].skb = skb_get(skb); tx = RING_GET_REQUEST(&np->tx, prod++); tx->id = id; ref = gnttab_claim_grant_reference(&np->gref_tx_head); BUG_ON((signed short)ref < 0); mfn = pfn_to_mfn(page_to_pfn(frag->page)); gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); tx->gref = np->grant_tx_ref[id] = ref; tx->offset = frag->page_offset; tx->size = frag->size; tx->flags = 0; } np->tx.req_prod_pvt = prod; }
static int map_data_for_request(struct vscsifrnt_info *info, struct scsi_cmnd *sc, struct vscsiif_request *ring_req, struct vscsifrnt_shadow *shadow) { grant_ref_t gref_head; struct page *page; int err, ref, ref_cnt = 0; int grant_ro = (sc->sc_data_direction == DMA_TO_DEVICE); unsigned int i, off, len, bytes; unsigned int data_len = scsi_bufflen(sc); unsigned int data_grants = 0, seg_grants = 0; struct scatterlist *sg; unsigned long mfn; struct scsiif_request_segment *seg; ring_req->nr_segments = 0; if (sc->sc_data_direction == DMA_NONE || !data_len) return 0; scsi_for_each_sg(sc, sg, scsi_sg_count(sc), i) data_grants += PFN_UP(sg->offset + sg->length); if (data_grants > VSCSIIF_SG_TABLESIZE) { if (data_grants > info->host->sg_tablesize) { shost_printk(KERN_ERR, info->host, KBUILD_MODNAME "Unable to map request_buffer for command!\n"); return -E2BIG; } seg_grants = vscsiif_grants_sg(data_grants); shadow->sg = kcalloc(data_grants, sizeof(struct scsiif_request_segment), GFP_ATOMIC); if (!shadow->sg) return -ENOMEM; } seg = shadow->sg ? : ring_req->seg; err = gnttab_alloc_grant_references(seg_grants + data_grants, &gref_head); if (err) { kfree(shadow->sg); shost_printk(KERN_ERR, info->host, KBUILD_MODNAME "gnttab_alloc_grant_references() error\n"); return -ENOMEM; } if (seg_grants) { page = virt_to_page(seg); off = (unsigned long)seg & ~PAGE_MASK; len = sizeof(struct scsiif_request_segment) * data_grants; while (len > 0) { bytes = min_t(unsigned int, len, PAGE_SIZE - off); ref = gnttab_claim_grant_reference(&gref_head); BUG_ON(ref == -ENOSPC); mfn = pfn_to_mfn(page_to_pfn(page)); gnttab_grant_foreign_access_ref(ref, info->dev->otherend_id, mfn, 1); shadow->gref[ref_cnt] = ref; ring_req->seg[ref_cnt].gref = ref; ring_req->seg[ref_cnt].offset = (uint16_t)off; ring_req->seg[ref_cnt].length = (uint16_t)bytes; page++; len -= bytes; off = 0; ref_cnt++; } BUG_ON(seg_grants < ref_cnt); seg_grants = ref_cnt; } scsi_for_each_sg(sc, sg, scsi_sg_count(sc), i) { page = sg_page(sg); off = sg->offset; len = sg->length; while (len > 0 && data_len > 0) { /* * sg sends a scatterlist that is larger than * the data_len it wants transferred for certain * IO sizes. */ bytes = min_t(unsigned int, len, PAGE_SIZE - off); bytes = min(bytes, data_len); ref = gnttab_claim_grant_reference(&gref_head); BUG_ON(ref == -ENOSPC); mfn = pfn_to_mfn(page_to_pfn(page)); gnttab_grant_foreign_access_ref(ref, info->dev->otherend_id, mfn, grant_ro); shadow->gref[ref_cnt] = ref; seg->gref = ref; seg->offset = (uint16_t)off; seg->length = (uint16_t)bytes; page++; seg++; len -= bytes; data_len -= bytes; off = 0; ref_cnt++; } }
static int xennet_start_xmit(struct sk_buff *skb, struct net_device *dev) { unsigned short id; struct netfront_info *np = netdev_priv(dev); struct netfront_stats *stats = this_cpu_ptr(np->stats); struct xen_netif_tx_request *tx; struct xen_netif_extra_info *extra; char *data = skb->data; RING_IDX i; grant_ref_t ref; unsigned long mfn; int notify; int slots; unsigned int offset = offset_in_page(data); unsigned int len = skb_headlen(skb); unsigned long flags; /* If skb->len is too big for wire format, drop skb and alert * user about misconfiguration. */ if (unlikely(skb->len > XEN_NETIF_MAX_TX_SIZE)) { net_alert_ratelimited( "xennet: skb->len = %u, too big for wire format\n", skb->len); goto drop; } slots = DIV_ROUND_UP(offset + len, PAGE_SIZE) + xennet_count_skb_frag_slots(skb); if (unlikely(slots > MAX_SKB_FRAGS + 1)) { net_alert_ratelimited( "xennet: skb rides the rocket: %d slots\n", slots); goto drop; } spin_lock_irqsave(&np->tx_lock, flags); if (unlikely(!netif_carrier_ok(dev) || (slots > 1 && !xennet_can_sg(dev)) || netif_needs_gso(skb, netif_skb_features(skb)))) { spin_unlock_irqrestore(&np->tx_lock, flags); goto drop; } i = np->tx.req_prod_pvt; id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); np->tx_skbs[id].skb = skb; tx = RING_GET_REQUEST(&np->tx, i); tx->id = id; ref = gnttab_claim_grant_reference(&np->gref_tx_head); BUG_ON((signed short)ref < 0); mfn = virt_to_mfn(data); gnttab_grant_foreign_access_ref( ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = len; extra = NULL; tx->flags = 0; if (skb->ip_summed == CHECKSUM_PARTIAL) /* local packet? */ tx->flags |= XEN_NETTXF_csum_blank | XEN_NETTXF_data_validated; else if (skb->ip_summed == CHECKSUM_UNNECESSARY) /* remote but checksummed. */ tx->flags |= XEN_NETTXF_data_validated; if (skb_shinfo(skb)->gso_size) { struct xen_netif_extra_info *gso; gso = (struct xen_netif_extra_info *) RING_GET_REQUEST(&np->tx, ++i); if (extra) extra->flags |= XEN_NETIF_EXTRA_FLAG_MORE; else tx->flags |= XEN_NETTXF_extra_info; gso->u.gso.size = skb_shinfo(skb)->gso_size; gso->u.gso.type = XEN_NETIF_GSO_TYPE_TCPV4; gso->u.gso.pad = 0; gso->u.gso.features = 0; gso->type = XEN_NETIF_EXTRA_TYPE_GSO; gso->flags = 0; extra = gso; } np->tx.req_prod_pvt = i + 1; xennet_make_frags(skb, dev, tx); tx->size = skb->len; RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->tx, notify); if (notify) notify_remote_via_irq(np->netdev->irq); u64_stats_update_begin(&stats->syncp); stats->tx_bytes += skb->len; stats->tx_packets++; u64_stats_update_end(&stats->syncp); /* Note: It is not safe to access skb after xennet_tx_buf_gc()! */ xennet_tx_buf_gc(dev); if (!netfront_tx_slot_available(np)) netif_stop_queue(dev); spin_unlock_irqrestore(&np->tx_lock, flags); return NETDEV_TX_OK; drop: dev->stats.tx_dropped++; dev_kfree_skb(skb); return NETDEV_TX_OK; }
static void xennet_make_frags(struct sk_buff *skb, struct net_device *dev, struct xen_netif_tx_request *tx) { struct netfront_info *np = netdev_priv(dev); char *data = skb->data; unsigned long mfn; RING_IDX prod = np->tx.req_prod_pvt; int frags = skb_shinfo(skb)->nr_frags; unsigned int offset = offset_in_page(data); unsigned int len = skb_headlen(skb); unsigned int id; grant_ref_t ref; int i; /* While the header overlaps a page boundary (including being larger than a page), split it it into page-sized chunks. */ while (len > PAGE_SIZE - offset) { tx->size = PAGE_SIZE - offset; tx->flags |= XEN_NETTXF_more_data; len -= tx->size; data += tx->size; offset = 0; id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); np->tx_skbs[id].skb = skb_get(skb); tx = RING_GET_REQUEST(&np->tx, prod++); tx->id = id; ref = gnttab_claim_grant_reference(&np->gref_tx_head); BUG_ON((signed short)ref < 0); mfn = virt_to_mfn(data); gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = len; tx->flags = 0; } /* Grant backend access to each skb fragment page. */ for (i = 0; i < frags; i++) { skb_frag_t *frag = skb_shinfo(skb)->frags + i; struct page *page = skb_frag_page(frag); len = skb_frag_size(frag); offset = frag->page_offset; /* Data must not cross a page boundary. */ BUG_ON(len + offset > PAGE_SIZE<<compound_order(page)); /* Skip unused frames from start of page */ page += offset >> PAGE_SHIFT; offset &= ~PAGE_MASK; while (len > 0) { unsigned long bytes; BUG_ON(offset >= PAGE_SIZE); bytes = PAGE_SIZE - offset; if (bytes > len) bytes = len; tx->flags |= XEN_NETTXF_more_data; id = get_id_from_freelist(&np->tx_skb_freelist, np->tx_skbs); np->tx_skbs[id].skb = skb_get(skb); tx = RING_GET_REQUEST(&np->tx, prod++); tx->id = id; ref = gnttab_claim_grant_reference(&np->gref_tx_head); BUG_ON((signed short)ref < 0); mfn = pfn_to_mfn(page_to_pfn(page)); gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, mfn, GNTMAP_readonly); tx->gref = np->grant_tx_ref[id] = ref; tx->offset = offset; tx->size = bytes; tx->flags = 0; offset += bytes; len -= bytes; /* Next frame */ if (offset == PAGE_SIZE && len) { BUG_ON(!PageCompound(page)); page++; offset = 0; } } } np->tx.req_prod_pvt = prod; }
/* * blkif_queue_request * * request block io * * id: for guest use only. * operation: BLKIF_OP_{READ,WRITE,PROBE} * buffer: buffer to read/write into. this should be a * virtual address in the guest os. */ int ixp_queue_request(struct app_request *app_req, void *metadata) { struct ixpfront_info *info = (struct ixpfront_info *) metadata; unsigned long buffer_mfn; struct ixp_request *ring_req; char *req_page = 0, *curr_pos; unsigned long id; int ref, err; grant_ref_t gref_head; if (unlikely(info->connected != IXP_STATE_CONNECTED)) return 1; if (RING_FULL(&info->ring)) { printk(KERN_ERR "%s:Ring full - returning backpressure\n", __FUNCTION__); return 1; } if (gnttab_alloc_grant_references( IXPIF_MAX_SEGMENTS_PER_REQUEST, &gref_head) < 0) { /*gnttab_request_free_callback( &info->callback, ixp_restart_queue_callback, info, IXP_MAX_SEGMENTS_PER_REQUEST);*/ return 1; } /* Fill out a communications ring structure. */ ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt); id = get_id_from_freelist(info); ring_req->id = id; ring_req->handle = info->handle; ring_req->operation = IXP_OP_3DES_ENCRYPT; ring_req->nr_segments = 1; BUG_ON(ring_req->nr_segments > IXPIF_MAX_SEGMENTS_PER_REQUEST); req_page = (char *)__get_free_page(GFP_NOIO | __GFP_HIGH); if(req_page == 0) { printk(KERN_ERR "ixp_queue_request:Error allocating memory"); return 1; } ((struct des_request *)req_page)->key_size = app_req->key_size; ((struct des_request *)req_page)->iv_size = app_req->iv_size; ((struct des_request *)req_page)->msg_size = app_req->msg_size; curr_pos = req_page + sizeof(struct des_request); memcpy(curr_pos, app_req->key, app_req->key_size); curr_pos += app_req->key_size; memcpy(curr_pos, app_req->iv, app_req->iv_size); curr_pos += app_req->iv_size; memcpy(curr_pos, app_req->msg, app_req->msg_size); curr_pos += app_req->msg_size; buffer_mfn = virt_to_mfn(req_page); /* install a grant reference. */ ref = gnttab_claim_grant_reference(&gref_head); BUG_ON(ref == -ENOSPC); gnttab_grant_foreign_access_ref( ref, info->xbdev->otherend_id, buffer_mfn, 0); info->shadow[id].r_params.presp = app_req->presp; info->shadow[id].r_params.callbk_tag = app_req->callbk_tag; info->shadow[id].frame[0] = mfn_to_pfn(buffer_mfn); info->shadow[id].req_page = req_page; ring_req->seg[0] = (struct ixp_request_segment) { .gref = ref }; info->ring.req_prod_pvt++; /* Keep a private copy so we can reissue requests when recovering. */ info->shadow[id].req = *ring_req; flush_requests(info); //gnttab_free_grant_references(gref_head); return 0; }
static void xennet_alloc_rx_buffers(struct net_device *dev) { unsigned short id; struct netfront_info *np = netdev_priv(dev); struct sk_buff *skb; struct page *page; int i, batch_target, notify; RING_IDX req_prod = np->rx.req_prod_pvt; grant_ref_t ref; unsigned long pfn; void *vaddr; struct xen_netif_rx_request *req; if (unlikely(!netif_carrier_ok(dev))) return; batch_target = np->rx_target - (req_prod - np->rx.rsp_cons); for (i = skb_queue_len(&np->rx_batch); i < batch_target; i++) { skb = __netdev_alloc_skb(dev, RX_COPY_THRESHOLD + NET_IP_ALIGN, GFP_ATOMIC | __GFP_NOWARN); if (unlikely(!skb)) goto no_skb; skb_reserve(skb, NET_IP_ALIGN); page = alloc_page(GFP_ATOMIC | __GFP_NOWARN); if (!page) { kfree_skb(skb); no_skb: if (i != 0) goto refill; mod_timer(&np->rx_refill_timer, jiffies + (HZ/10)); break; } skb_shinfo(skb)->frags[0].page = page; skb_shinfo(skb)->nr_frags = 1; __skb_queue_tail(&np->rx_batch, skb); } if (i < (np->rx_target/2)) { if (req_prod > np->rx.sring->req_prod) goto push; return; } if (((req_prod - np->rx.sring->rsp_prod) < (np->rx_target / 4)) && ((np->rx_target *= 2) > np->rx_max_target)) np->rx_target = np->rx_max_target; refill: for (i = 0; ; i++) { skb = __skb_dequeue(&np->rx_batch); if (skb == NULL) break; skb->dev = dev; id = xennet_rxidx(req_prod + i); BUG_ON(np->rx_skbs[id]); np->rx_skbs[id] = skb; ref = gnttab_claim_grant_reference(&np->gref_rx_head); BUG_ON((signed short)ref < 0); np->grant_rx_ref[id] = ref; pfn = page_to_pfn(skb_shinfo(skb)->frags[0].page); vaddr = page_address(skb_shinfo(skb)->frags[0].page); req = RING_GET_REQUEST(&np->rx, req_prod + i); gnttab_grant_foreign_access_ref(ref, np->xbdev->otherend_id, pfn_to_mfn(pfn), 0); req->id = id; req->gref = ref; } wmb(); np->rx.req_prod_pvt = req_prod + i; push: RING_PUSH_REQUESTS_AND_CHECK_NOTIFY(&np->rx, notify); if (notify) notify_remote_via_irq(np->netdev->irq); }