/* * Copyright 2012 Tilera Corporation. All Rights Reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License * as published by the Free Software Foundation, version 2. * * 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, GOOD TITLE or * NON INFRINGEMENT. See the GNU General Public License for * more details. */ #include #include #include #include #include /* printk() */ #include /* kmalloc() */ #include /* error codes */ #include /* size_t */ #include #include #include #include /* struct device, and other headers */ #include /* eth_type_trans */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include /* Default transmit lockup timeout period, in jiffies. */ #define TILE_NET_TIMEOUT (5 * HZ) /* The maximum number of distinct channels (idesc.channel is 5 bits). */ #define TILE_NET_CHANNELS 32 /* Maximum number of idescs to handle per "poll". */ #define TILE_NET_BATCH 128 /* Maximum number of packets to handle per "poll". */ #define TILE_NET_WEIGHT 64 /* Number of entries in each iqueue. */ #define IQUEUE_ENTRIES 512 /* Number of entries in each equeue. */ #define EQUEUE_ENTRIES 2048 /* Total header bytes per equeue slot. Must be big enough for 2 bytes * of NET_IP_ALIGN alignment, plus 14 bytes (?) of L2 header, plus up to * 60 bytes of actual TCP header. We round up to align to cache lines. */ #define HEADER_BYTES 128 /* Maximum completions per cpu per device (must be a power of two). * ISSUE: What is the right number here? If this is too small, then * egress might block waiting for free space in a completions array. * ISSUE: At the least, allocate these only for initialized echannels. */ #define TILE_NET_MAX_COMPS 64 #define MAX_FRAGS (MAX_SKB_FRAGS + 1) /* Size of completions data to allocate. * ISSUE: Probably more than needed since we don't use all the channels. */ #define COMPS_SIZE (TILE_NET_CHANNELS * sizeof(struct tile_net_comps)) /* Size of NotifRing data to allocate. */ #define NOTIF_RING_SIZE (IQUEUE_ENTRIES * sizeof(gxio_mpipe_idesc_t)) /* Timeout to wake the per-device TX timer after we stop the queue. * We don't want the timeout too short (adds overhead, and might end * up causing stop/wake/stop/wake cycles) or too long (affects performance). * For the 10 Gb NIC, 30 usec means roughly 30+ 1500-byte packets. */ #define TX_TIMER_DELAY_USEC 30 /* Timeout to wake the per-cpu egress timer to free completions. */ #define EGRESS_TIMER_DELAY_USEC 1000 MODULE_AUTHOR("Tilera Corporation"); MODULE_LICENSE("GPL"); /* A "packet fragment" (a chunk of memory). */ struct frag { void *buf; size_t length; }; /* A single completion. */ struct tile_net_comp { /* The "complete_count" when the completion will be complete. */ s64 when; /* The buffer to be freed when the completion is complete. */ struct sk_buff *skb; }; /* The completions for a given cpu and echannel. */ struct tile_net_comps { /* The completions. */ struct tile_net_comp comp_queue[TILE_NET_MAX_COMPS]; /* The number of completions used. */ unsigned long comp_next; /* The number of completions freed. */ unsigned long comp_last; }; /* The transmit wake timer for a given cpu and echannel. */ struct tile_net_tx_wake { int tx_queue_idx; struct hrtimer timer; struct net_device *dev; }; /* Info for a specific cpu. */ struct tile_net_info { /* The NAPI struct. */ struct napi_struct napi; /* Packet queue. */ gxio_mpipe_iqueue_t iqueue; /* Our cpu. */ int my_cpu; /* True if iqueue is valid. */ bool has_iqueue; /* NAPI flags. */ bool napi_added; bool napi_enabled; /* Number of small sk_buffs which must still be provided. */ unsigned int num_needed_small_buffers; /* Number of large sk_buffs which must still be provided. */ unsigned int num_needed_large_buffers; /* A timer for handling egress completions. */ struct hrtimer egress_timer; /* True if "egress_timer" is scheduled. */ bool egress_timer_scheduled; /* Comps for each egress channel. */ struct tile_net_comps *comps_for_echannel[TILE_NET_CHANNELS]; /* Transmit wake timer for each egress channel. */ struct tile_net_tx_wake tx_wake[TILE_NET_CHANNELS]; }; /* Info for egress on a particular egress channel. */ struct tile_net_egress { /* The "equeue". */ gxio_mpipe_equeue_t *equeue; /* The headers for TSO. */ unsigned char *headers; }; /* Info for a specific device. */ struct tile_net_priv { /* Our network device. */ struct net_device *dev; /* The primary link. */ gxio_mpipe_link_t link; /* The primary channel, if open, else -1. */ int channel; /* The "loopify" egress link, if needed. */ gxio_mpipe_link_t loopify_link; /* The "loopify" egress channel, if open, else -1. */ int loopify_channel; /* The egress channel (channel or loopify_channel). */ int echannel; /* Total stats. */ struct net_device_stats stats; }; /* Egress info, indexed by "priv->echannel" (lazily created as needed). */ static struct tile_net_egress egress_for_echannel[TILE_NET_CHANNELS]; /* Devices currently associated with each channel. * NOTE: The array entry can become NULL after ifconfig down, but * we do not free the underlying net_device structures, so it is * safe to use a pointer after reading it from this array. */ static struct net_device *tile_net_devs_for_channel[TILE_NET_CHANNELS]; /* A mutex for "tile_net_devs_for_channel". */ static DEFINE_MUTEX(tile_net_devs_for_channel_mutex); /* The per-cpu info. */ static DEFINE_PER_CPU(struct tile_net_info, per_cpu_info); /* The "context" for all devices. */ static gxio_mpipe_context_t context; /* Buffer sizes and mpipe enum codes for buffer stacks. * See arch/tile/include/gxio/mpipe.h for the set of possible values. */ #define BUFFER_SIZE_SMALL_ENUM GXIO_MPIPE_BUFFER_SIZE_128 #define BUFFER_SIZE_SMALL 128 #define BUFFER_SIZE_LARGE_ENUM GXIO_MPIPE_BUFFER_SIZE_1664 #define BUFFER_SIZE_LARGE 1664 /* The small/large "buffer stacks". */ static int small_buffer_stack = -1; static int large_buffer_stack = -1; /* Amount of memory allocated for each buffer stack. */ static size_t buffer_stack_size; /* The actual memory allocated for the buffer stacks. */ static void *small_buffer_stack_va; static void *large_buffer_stack_va; /* The buckets. */ static int first_bucket = -1; static int num_buckets = 1; /* The ingress irq. */ static int ingress_irq = -1; /* Text value of tile_net.cpus if passed as a module parameter. */ static char *network_cpus_string; /* The actual cpus in "network_cpus". */ static struct cpumask network_cpus_map; /* If "loopify=LINK" was specified, this is "LINK". */ static char *loopify_link_name; /* If "tile_net.custom" was specified, this is non-NULL. */ static char *custom_str; /* The "tile_net.cpus" argument specifies the cpus that are dedicated * to handle ingress packets. * * The parameter should be in the form "tile_net.cpus=m-n[,x-y]", where * m, n, x, y are integer numbers that represent the cpus that can be * neither a dedicated cpu nor a dataplane cpu. */ static bool network_cpus_init(void) { char buf[1024]; int rc; if (network_cpus_string == NULL) return false; rc = cpulist_parse_crop(network_cpus_string, &network_cpus_map); if (rc != 0) { pr_warn("tile_net.cpus=%s: malformed cpu list\n", network_cpus_string); return false; } /* Remove dedicated cpus. */ cpumask_and(&network_cpus_map, &network_cpus_map, cpu_possible_mask); if (cpumask_empty(&network_cpus_map)) { pr_warn("Ignoring empty tile_net.cpus='%s'.\n", network_cpus_string); return false; } cpulist_scnprintf(buf, sizeof(buf), &network_cpus_map); pr_info("Linux network CPUs: %s\n", buf); return true; } module_param_named(cpus, network_cpus_string, charp, 0444); MODULE_PARM_DESC(cpus, "cpulist of cores that handle network interrupts"); /* The "tile_net.loopify=LINK" argument causes the named device to * actually use "loop0" for ingress, and "loop1" for egress. This * allows an app to sit between the actual link and linux, passing * (some) packets along to linux, and forwarding (some) packets sent * out by linux. */ module_param_named(loopify, loopify_link_name, charp, 0444); MODULE_PARM_DESC(loopify, "name the device to use loop0/1 for ingress/egress"); /* The "tile_net.custom" argument causes us to ignore the "conventional" * classifier metadata, in particular, the "l2_offset". */ module_param_named(custom, custom_str, charp, 0444); MODULE_PARM_DESC(custom, "indicates a (heavily) customized classifier"); /* Atomically update a statistics field. * Note that on TILE-Gx, this operation is fire-and-forget on the * issuing core (single-cycle dispatch) and takes only a few cycles * longer than a regular store when the request reaches the home cache. * No expensive bus management overhead is required. */ static void tile_net_stats_add(unsigned long value, unsigned long *field) { BUILD_BUG_ON(sizeof(atomic_long_t) != sizeof(unsigned long)); atomic_long_add(value, (atomic_long_t *)field); } /* Allocate and push a buffer. */ static bool tile_net_provide_buffer(bool small) { int stack = small ? small_buffer_stack : large_buffer_stack; const unsigned long buffer_alignment = 128; struct sk_buff *skb; int len; len = sizeof(struct sk_buff **) + buffer_alignment; len += (small ? BUFFER_SIZE_SMALL : BUFFER_SIZE_LARGE); skb = dev_alloc_skb(len); if (skb == NULL) return false; /* Make room for a back-pointer to 'skb' and guarantee alignment. */ skb_reserve(skb, sizeof(struct sk_buff **)); skb_reserve(skb, -(long)skb->data & (buffer_alignment - 1)); /* Save a back-pointer to 'skb'. */ *(struct sk_buff **)(skb->data - sizeof(struct sk_buff **)) = skb; /* Make sure "skb" and the back-pointer have been flushed. */ wmb(); gxio_mpipe_push_buffer(&context, stack, (void *)va_to_tile_io_addr(skb->data)); return true; } /* Convert a raw mpipe buffer to its matching skb pointer. */ static struct sk_buff *mpipe_buf_to_skb(void *va) { /* Acquire the associated "skb". */ struct sk_buff **skb_ptr = va - sizeof(*skb_ptr); struct sk_buff *skb = *skb_ptr; /* Paranoia. */ if (skb->data != va) { /* Panic here since there's a reasonable chance * that corrupt buffers means generic memory * corruption, with unpredictable system effects. */ panic("Corrupt linux buffer! va=%p, skb=%p, skb->data=%p", va, skb, skb->data); } return skb; } static void tile_net_pop_all_buffers(int stack) { for (;;) { tile_io_addr_t addr = (tile_io_addr_t)gxio_mpipe_pop_buffer(&context, stack); if (addr == 0) break; dev_kfree_skb_irq(mpipe_buf_to_skb(tile_io_addr_to_va(addr))); } } /* Provide linux buffers to mPIPE. */ static void tile_net_provide_needed_buffers(void) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); while (info->num_needed_small_buffers != 0) { if (!tile_net_provide_buffer(true)) goto oops; info->num_needed_small_buffers--; } while (info->num_needed_large_buffers != 0) { if (!tile_net_provide_buffer(false)) goto oops; info->num_needed_large_buffers--; } return; oops: /* Add a description to the page allocation failure dump. */ pr_notice("Tile %d still needs some buffers\n", info->my_cpu); } static inline bool filter_packet(struct net_device *dev, void *buf) { /* Filter packets received before we're up. */ if (dev == NULL || !(dev->flags & IFF_UP)) return true; /* Filter out packets that aren't for us. */ if (!(dev->flags & IFF_PROMISC) && !is_multicast_ether_addr(buf) && compare_ether_addr(dev->dev_addr, buf) != 0) return true; return false; } static void tile_net_receive_skb(struct net_device *dev, struct sk_buff *skb, gxio_mpipe_idesc_t *idesc, unsigned long len) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); struct tile_net_priv *priv = netdev_priv(dev); /* Encode the actual packet length. */ skb_put(skb, len); skb->protocol = eth_type_trans(skb, dev); /* Acknowledge "good" hardware checksums. */ if (idesc->cs && idesc->csum_seed_val == 0xFFFF) skb->ip_summed = CHECKSUM_UNNECESSARY; netif_receive_skb(skb); /* Update stats. */ tile_net_stats_add(1, &priv->stats.rx_packets); tile_net_stats_add(len, &priv->stats.rx_bytes); /* Need a new buffer. */ if (idesc->size == BUFFER_SIZE_SMALL_ENUM) info->num_needed_small_buffers++; else info->num_needed_large_buffers++; } /* Handle a packet. Return true if "processed", false if "filtered". */ static bool tile_net_handle_packet(gxio_mpipe_idesc_t *idesc) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); struct net_device *dev = tile_net_devs_for_channel[idesc->channel]; uint8_t l2_offset; void *va; void *buf; unsigned long len; bool filter; /* Drop packets for which no buffer was available. * NOTE: This happens under heavy load. */ if (idesc->be) { struct tile_net_priv *priv = netdev_priv(dev); tile_net_stats_add(1, &priv->stats.rx_dropped); gxio_mpipe_iqueue_consume(&info->iqueue, idesc); if (net_ratelimit()) pr_info("Dropping packet (insufficient buffers).\n"); return false; } /* Get the "l2_offset", if allowed. */ l2_offset = custom_str ? 0 : gxio_mpipe_idesc_get_l2_offset(idesc); /* Get the raw buffer VA (includes "headroom"). */ va = tile_io_addr_to_va((unsigned long)(long)idesc->va); /* Get the actual packet start/length. */ buf = va + l2_offset; len = idesc->l2_size - l2_offset; /* Point "va" at the raw buffer. */ va -= NET_IP_ALIGN; filter = filter_packet(dev, buf); if (filter) { gxio_mpipe_iqueue_drop(&info->iqueue, idesc); } else { struct sk_buff *skb = mpipe_buf_to_skb(va); /* Skip headroom, and any custom header. */ skb_reserve(skb, NET_IP_ALIGN + l2_offset); tile_net_receive_skb(dev, skb, idesc, len); } gxio_mpipe_iqueue_consume(&info->iqueue, idesc); return !filter; } /* Handle some packets for the current CPU. * * This function handles up to TILE_NET_BATCH idescs per call. * * ISSUE: Since we do not provide new buffers until this function is * complete, we must initially provide enough buffers for each network * cpu to fill its iqueue and also its batched idescs. * * ISSUE: The "rotting packet" race condition occurs if a packet * arrives after the queue appears to be empty, and before the * hypervisor interrupt is re-enabled. */ static int tile_net_poll(struct napi_struct *napi, int budget) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); unsigned int work = 0; gxio_mpipe_idesc_t *idesc; int i, n; /* Process packets. */ while ((n = gxio_mpipe_iqueue_try_peek(&info->iqueue, &idesc)) > 0) { for (i = 0; i < n; i++) { if (i == TILE_NET_BATCH) goto done; if (tile_net_handle_packet(idesc + i)) { if (++work >= budget) goto done; } } } /* There are no packets left. */ napi_complete(&info->napi); /* Re-enable hypervisor interrupts. */ gxio_mpipe_enable_notif_ring_interrupt(&context, info->iqueue.ring); /* HACK: Avoid the "rotting packet" problem. */ if (gxio_mpipe_iqueue_try_peek(&info->iqueue, &idesc) > 0) napi_schedule(&info->napi); /* ISSUE: Handle completions? */ done: tile_net_provide_needed_buffers(); return work; } /* Handle an ingress interrupt on the current cpu. */ static irqreturn_t tile_net_handle_ingress_irq(int irq, void *unused) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); napi_schedule(&info->napi); return IRQ_HANDLED; } /* Free some completions. This must be called with interrupts blocked. */ static int tile_net_free_comps(gxio_mpipe_equeue_t *equeue, struct tile_net_comps *comps, int limit, bool force_update) { int n = 0; while (comps->comp_last < comps->comp_next) { unsigned int cid = comps->comp_last % TILE_NET_MAX_COMPS; struct tile_net_comp *comp = &comps->comp_queue[cid]; if (!gxio_mpipe_equeue_is_complete(equeue, comp->when, force_update || n == 0)) break; dev_kfree_skb_irq(comp->skb); comps->comp_last++; if (++n == limit) break; } return n; } /* Add a completion. This must be called with interrupts blocked. * tile_net_equeue_try_reserve() will have ensured a free completion entry. */ static void add_comp(gxio_mpipe_equeue_t *equeue, struct tile_net_comps *comps, uint64_t when, struct sk_buff *skb) { int cid = comps->comp_next % TILE_NET_MAX_COMPS; comps->comp_queue[cid].when = when; comps->comp_queue[cid].skb = skb; comps->comp_next++; } static void tile_net_schedule_tx_wake_timer(struct net_device *dev, int tx_queue_idx) { struct tile_net_info *info = &per_cpu(per_cpu_info, tx_queue_idx); struct tile_net_priv *priv = netdev_priv(dev); struct tile_net_tx_wake *tx_wake = &info->tx_wake[priv->echannel]; hrtimer_start(&tx_wake->timer, ktime_set(0, TX_TIMER_DELAY_USEC * 1000UL), HRTIMER_MODE_REL_PINNED); } static enum hrtimer_restart tile_net_handle_tx_wake_timer(struct hrtimer *t) { struct tile_net_tx_wake *tx_wake = container_of(t, struct tile_net_tx_wake, timer); netif_wake_subqueue(tx_wake->dev, tx_wake->tx_queue_idx); return HRTIMER_NORESTART; } /* Make sure the egress timer is scheduled. */ static void tile_net_schedule_egress_timer(void) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); if (!info->egress_timer_scheduled) { hrtimer_start(&info->egress_timer, ktime_set(0, EGRESS_TIMER_DELAY_USEC * 1000UL), HRTIMER_MODE_REL_PINNED); info->egress_timer_scheduled = true; } } /* The "function" for "info->egress_timer". * * This timer will reschedule itself as long as there are any pending * completions expected for this tile. */ static enum hrtimer_restart tile_net_handle_egress_timer(struct hrtimer *t) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); unsigned long irqflags; bool pending = false; int i; local_irq_save(irqflags); /* The timer is no longer scheduled. */ info->egress_timer_scheduled = false; /* Free all possible comps for this tile. */ for (i = 0; i < TILE_NET_CHANNELS; i++) { struct tile_net_egress *egress = &egress_for_echannel[i]; struct tile_net_comps *comps = info->comps_for_echannel[i]; if (comps->comp_last >= comps->comp_next) continue; tile_net_free_comps(egress->equeue, comps, -1, true); pending = pending || (comps->comp_last < comps->comp_next); } /* Reschedule timer if needed. */ if (pending) tile_net_schedule_egress_timer(); local_irq_restore(irqflags); return HRTIMER_NORESTART; } /* Helper function for "tile_net_update()". * "dev" (i.e. arg) is the device being brought up or down, * or NULL if all devices are now down. */ static void tile_net_update_cpu(void *arg) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); struct net_device *dev = arg; if (!info->has_iqueue) return; if (dev != NULL) { if (!info->napi_added) { netif_napi_add(dev, &info->napi, tile_net_poll, TILE_NET_WEIGHT); info->napi_added = true; } if (!info->napi_enabled) { napi_enable(&info->napi); info->napi_enabled = true; } enable_percpu_irq(ingress_irq, 0); } else { disable_percpu_irq(ingress_irq); if (info->napi_enabled) { napi_disable(&info->napi); info->napi_enabled = false; } /* FIXME: Drain the iqueue. */ } } /* Helper function for tile_net_open() and tile_net_stop(). * Always called under tile_net_devs_for_channel_mutex. */ static int tile_net_update(struct net_device *dev) { static gxio_mpipe_rules_t rules; /* too big to fit on the stack */ bool saw_channel = false; int channel; int rc; int cpu; gxio_mpipe_rules_init(&rules, &context); for (channel = 0; channel < TILE_NET_CHANNELS; channel++) { if (tile_net_devs_for_channel[channel] == NULL) continue; if (!saw_channel) { saw_channel = true; gxio_mpipe_rules_begin(&rules, first_bucket, num_buckets, NULL); gxio_mpipe_rules_set_headroom(&rules, NET_IP_ALIGN); } gxio_mpipe_rules_add_channel(&rules, channel); } /* NOTE: This can fail if there is no classifier. * ISSUE: Can anything else cause it to fail? */ rc = gxio_mpipe_rules_commit(&rules); if (rc != 0) { netdev_warn(dev, "gxio_mpipe_rules_commit failed: %d\n", rc); return -EIO; } /* Update all cpus, sequentially (to protect "netif_napi_add()"). */ for_each_online_cpu(cpu) smp_call_function_single(cpu, tile_net_update_cpu, (saw_channel ? dev : NULL), 1); /* HACK: Allow packets to flow in the simulator. */ if (saw_channel) sim_enable_mpipe_links(0, -1); return 0; } /* Allocate and initialize mpipe buffer stacks, and register them in * the mPIPE TLBs, for both small and large packet sizes. * This routine supports tile_net_init_mpipe(), below. */ static int init_buffer_stacks(struct net_device *dev, int num_buffers) { pte_t hash_pte = pte_set_home((pte_t) { 0 }, PAGE_HOME_HASH); int rc; /* Compute stack bytes; we round up to 64KB and then use * alloc_pages() so we get the required 64KB alignment as well. */ buffer_stack_size = ALIGN(gxio_mpipe_calc_buffer_stack_bytes(num_buffers), 64 * 1024); /* Allocate two buffer stack indices. */ rc = gxio_mpipe_alloc_buffer_stacks(&context, 2, 0, 0); if (rc < 0) { netdev_err(dev, "gxio_mpipe_alloc_buffer_stacks failed: %d\n", rc); return rc; } small_buffer_stack = rc; large_buffer_stack = rc + 1; /* Allocate the small memory stack. */ small_buffer_stack_va = alloc_pages_exact(buffer_stack_size, GFP_KERNEL); if (small_buffer_stack_va == NULL) { netdev_err(dev, "Could not alloc %zd bytes for buffer stacks\n", buffer_stack_size); return -ENOMEM; } rc = gxio_mpipe_init_buffer_stack(&context, small_buffer_stack, BUFFER_SIZE_SMALL_ENUM, small_buffer_stack_va, buffer_stack_size, 0); if (rc != 0) { netdev_err(dev, "gxio_mpipe_init_buffer_stack: %d\n", rc); return rc; } rc = gxio_mpipe_register_client_memory(&context, small_buffer_stack, hash_pte, 0); if (rc != 0) { netdev_err(dev, "gxio_mpipe_register_buffer_memory failed: %d\n", rc); return rc; } /* Allocate the large buffer stack. */ large_buffer_stack_va = alloc_pages_exact(buffer_stack_size, GFP_KERNEL); if (large_buffer_stack_va == NULL) { netdev_err(dev, "Could not alloc %zd bytes for buffer stacks\n", buffer_stack_size); return -ENOMEM; } rc = gxio_mpipe_init_buffer_stack(&context, large_buffer_stack, BUFFER_SIZE_LARGE_ENUM, large_buffer_stack_va, buffer_stack_size, 0); if (rc != 0) { netdev_err(dev, "gxio_mpipe_init_buffer_stack failed: %d\n", rc); return rc; } rc = gxio_mpipe_register_client_memory(&context, large_buffer_stack, hash_pte, 0); if (rc != 0) { netdev_err(dev, "gxio_mpipe_register_buffer_memory failed: %d\n", rc); return rc; } return 0; } /* Allocate per-cpu resources (memory for completions and idescs). * This routine supports tile_net_init_mpipe(), below. */ static int alloc_percpu_mpipe_resources(struct net_device *dev, int cpu, int ring) { struct tile_net_info *info = &per_cpu(per_cpu_info, cpu); int order, i, rc; struct page *page; void *addr; /* Allocate the "comps". */ order = get_order(COMPS_SIZE); page = homecache_alloc_pages(GFP_KERNEL, order, cpu); if (page == NULL) { netdev_err(dev, "Failed to alloc %zd bytes comps memory\n", COMPS_SIZE); return -ENOMEM; } addr = pfn_to_kaddr(page_to_pfn(page)); memset(addr, 0, COMPS_SIZE); for (i = 0; i < TILE_NET_CHANNELS; i++) info->comps_for_echannel[i] = addr + i * sizeof(struct tile_net_comps); /* If this is a network cpu, create an iqueue. */ if (cpu_isset(cpu, network_cpus_map)) { order = get_order(NOTIF_RING_SIZE); page = homecache_alloc_pages(GFP_KERNEL, order, cpu); if (page == NULL) { netdev_err(dev, "Failed to alloc %zd bytes iqueue memory\n", NOTIF_RING_SIZE); return -ENOMEM; } addr = pfn_to_kaddr(page_to_pfn(page)); rc = gxio_mpipe_iqueue_init(&info->iqueue, &context, ring++, addr, NOTIF_RING_SIZE, 0); if (rc < 0) { netdev_err(dev, "gxio_mpipe_iqueue_init failed: %d\n", rc); return rc; } info->has_iqueue = true; } return ring; } /* Initialize NotifGroup and buckets. * This routine supports tile_net_init_mpipe(), below. */ static int init_notif_group_and_buckets(struct net_device *dev, int ring, int network_cpus_count) { int group, rc; /* Allocate one NotifGroup. */ rc = gxio_mpipe_alloc_notif_groups(&context, 1, 0, 0); if (rc < 0) { netdev_err(dev, "gxio_mpipe_alloc_notif_groups failed: %d\n", rc); return rc; } group = rc; /* Initialize global num_buckets value. */ if (network_cpus_count > 4) num_buckets = 256; else if (network_cpus_count > 1) num_buckets = 16; /* Allocate some buckets, and set global first_bucket value. */ rc = gxio_mpipe_alloc_buckets(&context, num_buckets, 0, 0); if (rc < 0) { netdev_err(dev, "gxio_mpipe_alloc_buckets failed: %d\n", rc); return rc; } first_bucket = rc; /* Init group and buckets. */ rc = gxio_mpipe_init_notif_group_and_buckets( &context, group, ring, network_cpus_count, first_bucket, num_buckets, GXIO_MPIPE_BUCKET_STICKY_FLOW_LOCALITY); if (rc != 0) { netdev_err( dev, "gxio_mpipe_init_notif_group_and_buckets failed: %d\n", rc); return rc; } return 0; } /* Create an irq and register it, then activate the irq and request * interrupts on all cores. Note that "ingress_irq" being initialized * is how we know not to call tile_net_init_mpipe() again. * This routine supports tile_net_init_mpipe(), below. */ static int tile_net_setup_interrupts(struct net_device *dev) { int cpu, rc; rc = create_irq(); if (rc < 0) { netdev_err(dev, "create_irq failed: %d\n", rc); return rc; } ingress_irq = rc; tile_irq_activate(ingress_irq, TILE_IRQ_PERCPU); rc = request_irq(ingress_irq, tile_net_handle_ingress_irq, 0, "tile_net", NULL); if (rc != 0) { netdev_err(dev, "request_irq failed: %d\n", rc); destroy_irq(ingress_irq); ingress_irq = -1; return rc; } for_each_online_cpu(cpu) { struct tile_net_info *info = &per_cpu(per_cpu_info, cpu); if (info->has_iqueue) { gxio_mpipe_request_notif_ring_interrupt( &context, cpu_x(cpu), cpu_y(cpu), KERNEL_PL, ingress_irq, info->iqueue.ring); } } return 0; } /* Undo any state set up partially by a failed call to tile_net_init_mpipe. */ static void tile_net_init_mpipe_fail(void) { int cpu; /* Do cleanups that require the mpipe context first. */ if (small_buffer_stack >= 0) tile_net_pop_all_buffers(small_buffer_stack); if (large_buffer_stack >= 0) tile_net_pop_all_buffers(large_buffer_stack); /* Destroy mpipe context so the hardware no longer owns any memory. */ gxio_mpipe_destroy(&context); for_each_online_cpu(cpu) { struct tile_net_info *info = &per_cpu(per_cpu_info, cpu); free_pages((unsigned long)(info->comps_for_echannel[0]), get_order(COMPS_SIZE)); info->comps_for_echannel[0] = NULL; free_pages((unsigned long)(info->iqueue.idescs), get_order(NOTIF_RING_SIZE)); info->iqueue.idescs = NULL; } if (small_buffer_stack_va) free_pages_exact(small_buffer_stack_va, buffer_stack_size); if (large_buffer_stack_va) free_pages_exact(large_buffer_stack_va, buffer_stack_size); small_buffer_stack_va = NULL; large_buffer_stack_va = NULL; large_buffer_stack = -1; small_buffer_stack = -1; first_bucket = -1; } /* The first time any tilegx network device is opened, we initialize * the global mpipe state. If this step fails, we fail to open the * device, but if it succeeds, we never need to do it again, and since * tile_net can't be unloaded, we never undo it. * * Note that some resources in this path (buffer stack indices, * bindings from init_buffer_stack, etc.) are hypervisor resources * that are freed implicitly by gxio_mpipe_destroy(). */ static int tile_net_init_mpipe(struct net_device *dev) { int i, num_buffers, rc; int cpu; int first_ring, ring; int network_cpus_count = cpus_weight(network_cpus_map); if (!hash_default) { netdev_err(dev, "Networking requires hash_default!\n"); return -EIO; } rc = gxio_mpipe_init(&context, 0); if (rc != 0) { netdev_err(dev, "gxio_mpipe_init failed: %d\n", rc); return -EIO; } /* Set up the buffer stacks. */ num_buffers = network_cpus_count * (IQUEUE_ENTRIES + TILE_NET_BATCH); rc = init_buffer_stacks(dev, num_buffers); if (rc != 0) goto fail; /* Provide initial buffers. */ rc = -ENOMEM; for (i = 0; i < num_buffers; i++) { if (!tile_net_provide_buffer(true)) { netdev_err(dev, "Cannot allocate initial sk_bufs!\n"); goto fail; } } for (i = 0; i < num_buffers; i++) { if (!tile_net_provide_buffer(false)) { netdev_err(dev, "Cannot allocate initial sk_bufs!\n"); goto fail; } } /* Allocate one NotifRing for each network cpu. */ rc = gxio_mpipe_alloc_notif_rings(&context, network_cpus_count, 0, 0); if (rc < 0) { netdev_err(dev, "gxio_mpipe_alloc_notif_rings failed %d\n", rc); goto fail; } /* Init NotifRings per-cpu. */ first_ring = rc; ring = first_ring; for_each_online_cpu(cpu) { rc = alloc_percpu_mpipe_resources(dev, cpu, ring); if (rc < 0) goto fail; ring = rc; } /* Initialize NotifGroup and buckets. */ rc = init_notif_group_and_buckets(dev, first_ring, network_cpus_count); if (rc != 0) goto fail; /* Create and enable interrupts. */ rc = tile_net_setup_interrupts(dev); if (rc != 0) goto fail; return 0; fail: tile_net_init_mpipe_fail(); return rc; } /* Create persistent egress info for a given egress channel. * Note that this may be shared between, say, "gbe0" and "xgbe0". * ISSUE: Defer header allocation until TSO is actually needed? */ static int tile_net_init_egress(struct net_device *dev, int echannel) { struct page *headers_page, *edescs_page, *equeue_page; gxio_mpipe_edesc_t *edescs; gxio_mpipe_equeue_t *equeue; unsigned char *headers; int headers_order, edescs_order, equeue_order; size_t edescs_size; int edma; int rc = -ENOMEM; /* Only initialize once. */ if (egress_for_echannel[echannel].equeue != NULL) return 0; /* Allocate memory for the "headers". */ headers_order = get_order(EQUEUE_ENTRIES * HEADER_BYTES); headers_page = alloc_pages(GFP_KERNEL, headers_order); if (headers_page == NULL) { netdev_warn(dev, "Could not alloc %zd bytes for TSO headers.\n", PAGE_SIZE << headers_order); goto fail; } headers = pfn_to_kaddr(page_to_pfn(headers_page)); /* Allocate memory for the "edescs". */ edescs_size = EQUEUE_ENTRIES * sizeof(*edescs); edescs_order = get_order(edescs_size); edescs_page = alloc_pages(GFP_KERNEL, edescs_order); if (edescs_page == NULL) { netdev_warn(dev, "Could not alloc %zd bytes for eDMA ring.\n", edescs_size); goto fail_headers; } edescs = pfn_to_kaddr(page_to_pfn(edescs_page)); /* Allocate memory for the "equeue". */ equeue_order = get_order(sizeof(*equeue)); equeue_page = alloc_pages(GFP_KERNEL, equeue_order); if (equeue_page == NULL) { netdev_warn(dev, "Could not alloc %zd bytes for equeue info.\n", PAGE_SIZE << equeue_order); goto fail_edescs; } equeue = pfn_to_kaddr(page_to_pfn(equeue_page)); /* Allocate an edma ring. Note that in practice this can't * fail, which is good, because we will leak an edma ring if so. */ rc = gxio_mpipe_alloc_edma_rings(&context, 1, 0, 0); if (rc < 0) { netdev_warn(dev, "gxio_mpipe_alloc_edma_rings failed: %d\n", rc); goto fail_equeue; } edma = rc; /* Initialize the equeue. */ rc = gxio_mpipe_equeue_init(equeue, &context, edma, echannel, edescs, edescs_size, 0); if (rc != 0) { netdev_err(dev, "gxio_mpipe_equeue_init failed: %d\n", rc); goto fail_equeue; } /* Done. */ egress_for_echannel[echannel].equeue = equeue; egress_for_echannel[echannel].headers = headers; return 0; fail_equeue: __free_pages(equeue_page, equeue_order); fail_edescs: __free_pages(edescs_page, edescs_order); fail_headers: __free_pages(headers_page, headers_order); fail: return rc; } /* Return channel number for a newly-opened link. */ static int tile_net_link_open(struct net_device *dev, gxio_mpipe_link_t *link, const char *link_name) { int rc = gxio_mpipe_link_open(link, &context, link_name, 0); if (rc < 0) { netdev_err(dev, "Failed to open '%s'\n", link_name); return rc; } rc = gxio_mpipe_link_channel(link); if (rc < 0 || rc >= TILE_NET_CHANNELS) { netdev_err(dev, "gxio_mpipe_link_channel bad value: %d\n", rc); gxio_mpipe_link_close(link); return -EINVAL; } return rc; } /* Help the kernel activate the given network interface. */ static int tile_net_open(struct net_device *dev) { struct tile_net_priv *priv = netdev_priv(dev); int cpu, rc; mutex_lock(&tile_net_devs_for_channel_mutex); /* Do one-time initialization the first time any device is opened. */ if (ingress_irq < 0) { rc = tile_net_init_mpipe(dev); if (rc != 0) goto fail; } /* Determine if this is the "loopify" device. */ if (unlikely((loopify_link_name != NULL) && !strcmp(dev->name, loopify_link_name))) { rc = tile_net_link_open(dev, &priv->link, "loop0"); if (rc < 0) goto fail; priv->channel = rc; rc = tile_net_link_open(dev, &priv->loopify_link, "loop1"); if (rc < 0) goto fail; priv->loopify_channel = rc; priv->echannel = rc; } else { rc = tile_net_link_open(dev, &priv->link, dev->name); if (rc < 0) goto fail; priv->channel = rc; priv->echannel = rc; } /* Initialize egress info (if needed). Once ever, per echannel. */ rc = tile_net_init_egress(dev, priv->echannel); if (rc != 0) goto fail; tile_net_devs_for_channel[priv->channel] = dev; rc = tile_net_update(dev); if (rc != 0) goto fail; mutex_unlock(&tile_net_devs_for_channel_mutex); /* Initialize the transmit wake timer for this device for each cpu. */ for_each_online_cpu(cpu) { struct tile_net_info *info = &per_cpu(per_cpu_info, cpu); struct tile_net_tx_wake *tx_wake = &info->tx_wake[priv->echannel]; hrtimer_init(&tx_wake->timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); tx_wake->tx_queue_idx = cpu; tx_wake->timer.function = tile_net_handle_tx_wake_timer; tx_wake->dev = dev; } for_each_online_cpu(cpu) netif_start_subqueue(dev, cpu); netif_carrier_on(dev); return 0; fail: if (priv->loopify_channel >= 0) { if (gxio_mpipe_link_close(&priv->loopify_link) != 0) netdev_warn(dev, "Failed to close loopify link!\n"); priv->loopify_channel = -1; } if (priv->channel >= 0) { if (gxio_mpipe_link_close(&priv->link) != 0) netdev_warn(dev, "Failed to close link!\n"); priv->channel = -1; } priv->echannel = -1; tile_net_devs_for_channel[priv->channel] = NULL; mutex_unlock(&tile_net_devs_for_channel_mutex); /* Don't return raw gxio error codes to generic Linux. */ return (rc > -512) ? rc : -EIO; } /* Help the kernel deactivate the given network interface. */ static int tile_net_stop(struct net_device *dev) { struct tile_net_priv *priv = netdev_priv(dev); int cpu; for_each_online_cpu(cpu) { struct tile_net_info *info = &per_cpu(per_cpu_info, cpu); struct tile_net_tx_wake *tx_wake = &info->tx_wake[priv->echannel]; hrtimer_cancel(&tx_wake->timer); netif_stop_subqueue(dev, cpu); } mutex_lock(&tile_net_devs_for_channel_mutex); tile_net_devs_for_channel[priv->channel] = NULL; (void)tile_net_update(dev); if (priv->loopify_channel >= 0) { if (gxio_mpipe_link_close(&priv->loopify_link) != 0) netdev_warn(dev, "Failed to close loopify link!\n"); priv->loopify_channel = -1; } if (priv->channel >= 0) { if (gxio_mpipe_link_close(&priv->link) != 0) netdev_warn(dev, "Failed to close link!\n"); priv->channel = -1; } priv->echannel = -1; mutex_unlock(&tile_net_devs_for_channel_mutex); return 0; } /* Determine the VA for a fragment. */ static inline void *tile_net_frag_buf(skb_frag_t *f) { unsigned long pfn = page_to_pfn(skb_frag_page(f)); return pfn_to_kaddr(pfn) + f->page_offset; } /* Acquire a completion entry and an egress slot, or if we can't, * stop the queue and schedule the tx_wake timer. */ static s64 tile_net_equeue_try_reserve(struct net_device *dev, int tx_queue_idx, struct tile_net_comps *comps, gxio_mpipe_equeue_t *equeue, int num_edescs) { /* Try to acquire a completion entry. */ if (comps->comp_next - comps->comp_last < TILE_NET_MAX_COMPS - 1 || tile_net_free_comps(equeue, comps, 32, false) != 0) { /* Try to acquire an egress slot. */ s64 slot = gxio_mpipe_equeue_try_reserve(equeue, num_edescs); if (slot >= 0) return slot; /* Freeing some completions gives the equeue time to drain. */ tile_net_free_comps(equeue, comps, TILE_NET_MAX_COMPS, false); slot = gxio_mpipe_equeue_try_reserve(equeue, num_edescs); if (slot >= 0) return slot; } /* Still nothing; give up and stop the queue for a short while. */ netif_stop_subqueue(dev, tx_queue_idx); tile_net_schedule_tx_wake_timer(dev, tx_queue_idx); return -1; } /* Determine how many edesc's are needed for TSO. * * Sometimes, if "sendfile()" requires copying, we will be called with * "data" containing the header and payload, with "frags" being empty. * Sometimes, for example when using NFS over TCP, a single segment can * span 3 fragments. This requires special care. */ static int tso_count_edescs(struct sk_buff *skb) { struct skb_shared_info *sh = skb_shinfo(skb); unsigned int sh_len = skb_transport_offset(skb) + tcp_hdrlen(skb); unsigned int data_len = skb->len - sh_len; unsigned int p_len = sh->gso_size; long f_id = -1; /* id of the current fragment */ long f_size = skb_headlen(skb) - sh_len; /* current fragment size */ long f_used = 0; /* bytes used from the current fragment */ long n; /* size of the current piece of payload */ int num_edescs = 0; int segment; for (segment = 0; segment < sh->gso_segs; segment++) { unsigned int p_used = 0; /* One edesc for header and for each piece of the payload. */ for (num_edescs++; p_used < p_len; num_edescs++) { /* Advance as needed. */ while (f_used >= f_size) { f_id++; f_size = skb_frag_size(&sh->frags[f_id]); f_used = 0; } /* Use bytes from the current fragment. */ n = p_len - p_used; if (n > f_size - f_used) n = f_size - f_used; f_used += n; p_used += n; } /* The last segment may be less than gso_size. */ data_len -= p_len; if (data_len < p_len) p_len = data_len; } return num_edescs; } /* Prepare modified copies of the skbuff headers. * FIXME: add support for IPv6. */ static void tso_headers_prepare(struct sk_buff *skb, unsigned char *headers, s64 slot) { struct skb_shared_info *sh = skb_shinfo(skb); struct iphdr *ih; struct tcphdr *th; unsigned int sh_len = skb_transport_offset(skb) + tcp_hdrlen(skb); unsigned int data_len = skb->len - sh_len; unsigned char *data = skb->data; unsigned int ih_off, th_off, p_len; unsigned int isum_seed, tsum_seed, id, seq; long f_id = -1; /* id of the current fragment */ long f_size = skb_headlen(skb) - sh_len; /* current fragment size */ long f_used = 0; /* bytes used from the current fragment */ long n; /* size of the current piece of payload */ int segment; /* Locate original headers and compute various lengths. */ ih = ip_hdr(skb); th = tcp_hdr(skb); ih_off = skb_network_offset(skb); th_off = skb_transport_offset(skb); p_len = sh->gso_size; /* Set up seed values for IP and TCP csum and initialize id and seq. */ isum_seed = ((0xFFFF - ih->check) + (0xFFFF - ih->tot_len) + (0xFFFF - ih->id)); tsum_seed = th->check + (0xFFFF ^ htons(skb->len)); id = ntohs(ih->id); seq = ntohl(th->seq); /* Prepare all the headers. */ for (segment = 0; segment < sh->gso_segs; segment++) { unsigned char *buf; unsigned int p_used = 0; /* Copy to the header memory for this segment. */ buf = headers + (slot % EQUEUE_ENTRIES) * HEADER_BYTES + NET_IP_ALIGN; memcpy(buf, data, sh_len); /* Update copied ip header. */ ih = (struct iphdr *)(buf + ih_off); ih->tot_len = htons(sh_len + p_len - ih_off); ih->id = htons(id); ih->check = csum_long(isum_seed + ih->tot_len + ih->id) ^ 0xffff; /* Update copied tcp header. */ th = (struct tcphdr *)(buf + th_off); th->seq = htonl(seq); th->check = csum_long(tsum_seed + htons(sh_len + p_len)); if (segment != sh->gso_segs - 1) { th->fin = 0; th->psh = 0; } /* Skip past the header. */ slot++; /* Skip past the payload. */ while (p_used < p_len) { /* Advance as needed. */ while (f_used >= f_size) { f_id++; f_size = skb_frag_size(&sh->frags[f_id]); f_used = 0; } /* Use bytes from the current fragment. */ n = p_len - p_used; if (n > f_size - f_used) n = f_size - f_used; f_used += n; p_used += n; slot++; } id++; seq += p_len; /* The last segment may be less than gso_size. */ data_len -= p_len; if (data_len < p_len) p_len = data_len; } /* Flush the headers so they are ready for hardware DMA. */ wmb(); } /* Pass all the data to mpipe for egress. */ static void tso_egress(struct net_device *dev, gxio_mpipe_equeue_t *equeue, struct sk_buff *skb, unsigned char *headers, s64 slot) { struct tile_net_priv *priv = netdev_priv(dev); struct skb_shared_info *sh = skb_shinfo(skb); unsigned int sh_len = skb_transport_offset(skb) + tcp_hdrlen(skb); unsigned int data_len = skb->len - sh_len; unsigned int p_len = sh->gso_size; gxio_mpipe_edesc_t edesc_head = { { 0 } }; gxio_mpipe_edesc_t edesc_body = { { 0 } }; long f_id = -1; /* id of the current fragment */ long f_size = skb_headlen(skb) - sh_len; /* current fragment size */ long f_used = 0; /* bytes used from the current fragment */ void *f_data = skb->data + sh_len; long n; /* size of the current piece of payload */ unsigned long tx_packets = 0, tx_bytes = 0; unsigned int csum_start; int segment; /* Prepare to egress the headers: set up header edesc. */ csum_start = skb_checksum_start_offset(skb); edesc_head.csum = 1; edesc_head.csum_start = csum_start; edesc_head.csum_dest = csum_start + skb->csum_offset; edesc_head.xfer_size = sh_len; /* This is only used to specify the TLB. */ edesc_head.stack_idx = large_buffer_stack; edesc_body.stack_idx = large_buffer_stack; /* Egress all the edescs. */ for (segment = 0; segment < sh->gso_segs; segment++) { unsigned char *buf; unsigned int p_used = 0; /* Egress the header. */ buf = headers + (slot % EQUEUE_ENTRIES) * HEADER_BYTES + NET_IP_ALIGN; edesc_head.va = va_to_tile_io_addr(buf); gxio_mpipe_equeue_put_at(equeue, edesc_head, slot); slot++; /* Egress the payload. */ while (p_used < p_len) { void *va; /* Advance as needed. */ while (f_used >= f_size) { f_id++; f_size = skb_frag_size(&sh->frags[f_id]); f_data = tile_net_frag_buf(&sh->frags[f_id]); f_used = 0; } va = f_data + f_used; /* Use bytes from the current fragment. */ n = p_len - p_used; if (n > f_size - f_used) n = f_size - f_used; f_used += n; p_used += n; /* Egress a piece of the payload. */ edesc_body.va = va_to_tile_io_addr(va); edesc_body.xfer_size = n; edesc_body.bound = !(p_used < p_len); gxio_mpipe_equeue_put_at(equeue, edesc_body, slot); slot++; } tx_packets++; tx_bytes += sh_len + p_len; /* The last segment may be less than gso_size. */ data_len -= p_len; if (data_len < p_len) p_len = data_len; } /* Update stats. */ tile_net_stats_add(tx_packets, &priv->stats.tx_packets); tile_net_stats_add(tx_bytes, &priv->stats.tx_bytes); } /* Do "TSO" handling for egress. * * Normally drivers set NETIF_F_TSO only to support hardware TSO; * otherwise the stack uses scatter-gather to implement GSO in software. * On our testing, enabling GSO support (via NETIF_F_SG) drops network * performance down to around 7.5 Gbps on the 10G interfaces, although * also dropping cpu utilization way down, to under 8%. But * implementing "TSO" in the driver brings performance back up to line * rate, while dropping cpu usage even further, to less than 4%. In * practice, profiling of GSO shows that skb_segment() is what causes * the performance overheads; we benefit in the driver from using * preallocated memory to duplicate the TCP/IP headers. */ static int tile_net_tx_tso(struct sk_buff *skb, struct net_device *dev) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); struct tile_net_priv *priv = netdev_priv(dev); int channel = priv->echannel; struct tile_net_egress *egress = &egress_for_echannel[channel]; struct tile_net_comps *comps = info->comps_for_echannel[channel]; gxio_mpipe_equeue_t *equeue = egress->equeue; unsigned long irqflags; int num_edescs; s64 slot; /* Determine how many mpipe edesc's are needed. */ num_edescs = tso_count_edescs(skb); local_irq_save(irqflags); /* Try to acquire a completion entry and an egress slot. */ slot = tile_net_equeue_try_reserve(dev, skb->queue_mapping, comps, equeue, num_edescs); if (slot < 0) { local_irq_restore(irqflags); return NETDEV_TX_BUSY; } /* Set up copies of header data properly. */ tso_headers_prepare(skb, egress->headers, slot); /* Actually pass the data to the network hardware. */ tso_egress(dev, equeue, skb, egress->headers, slot); /* Add a completion record. */ add_comp(equeue, comps, slot + num_edescs - 1, skb); local_irq_restore(irqflags); /* Make sure the egress timer is scheduled. */ tile_net_schedule_egress_timer(); return NETDEV_TX_OK; } /* Analyze the body and frags for a transmit request. */ static unsigned int tile_net_tx_frags(struct frag *frags, struct sk_buff *skb, void *b_data, unsigned int b_len) { unsigned int i, n = 0; struct skb_shared_info *sh = skb_shinfo(skb); if (b_len != 0) { frags[n].buf = b_data; frags[n++].length = b_len; } for (i = 0; i < sh->nr_frags; i++) { skb_frag_t *f = &sh->frags[i]; frags[n].buf = tile_net_frag_buf(f); frags[n++].length = skb_frag_size(f); } return n; } /* Help the kernel transmit a packet. */ static int tile_net_tx(struct sk_buff *skb, struct net_device *dev) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); struct tile_net_priv *priv = netdev_priv(dev); struct tile_net_egress *egress = &egress_for_echannel[priv->echannel]; gxio_mpipe_equeue_t *equeue = egress->equeue; struct tile_net_comps *comps = info->comps_for_echannel[priv->echannel]; unsigned int len = skb->len; unsigned char *data = skb->data; unsigned int num_edescs; struct frag frags[MAX_FRAGS]; gxio_mpipe_edesc_t edescs[MAX_FRAGS]; unsigned long irqflags; gxio_mpipe_edesc_t edesc = { { 0 } }; unsigned int i; s64 slot; if (skb_is_gso(skb)) return tile_net_tx_tso(skb, dev); num_edescs = tile_net_tx_frags(frags, skb, data, skb_headlen(skb)); /* This is only used to specify the TLB. */ edesc.stack_idx = large_buffer_stack; /* Prepare the edescs. */ for (i = 0; i < num_edescs; i++) { edesc.xfer_size = frags[i].length; edesc.va = va_to_tile_io_addr(frags[i].buf); edescs[i] = edesc; } /* Mark the final edesc. */ edescs[num_edescs - 1].bound = 1; /* Add checksum info to the initial edesc, if needed. */ if (skb->ip_summed == CHECKSUM_PARTIAL) { unsigned int csum_start = skb_checksum_start_offset(skb); edescs[0].csum = 1; edescs[0].csum_start = csum_start; edescs[0].csum_dest = csum_start + skb->csum_offset; } local_irq_save(irqflags); /* Try to acquire a completion entry and an egress slot. */ slot = tile_net_equeue_try_reserve(dev, skb->queue_mapping, comps, equeue, num_edescs); if (slot < 0) { local_irq_restore(irqflags); return NETDEV_TX_BUSY; } for (i = 0; i < num_edescs; i++) gxio_mpipe_equeue_put_at(equeue, edescs[i], slot++); /* Add a completion record. */ add_comp(equeue, comps, slot - 1, skb); /* NOTE: Use ETH_ZLEN for short packets (e.g. 42 < 60). */ tile_net_stats_add(1, &priv->stats.tx_packets); tile_net_stats_add(max_t(unsigned int, len, ETH_ZLEN), &priv->stats.tx_bytes); local_irq_restore(irqflags); /* Make sure the egress timer is scheduled. */ tile_net_schedule_egress_timer(); return NETDEV_TX_OK; } /* Return subqueue id on this core (one per core). */ static u16 tile_net_select_queue(struct net_device *dev, struct sk_buff *skb) { return smp_processor_id(); } /* Deal with a transmit timeout. */ static void tile_net_tx_timeout(struct net_device *dev) { int cpu; for_each_online_cpu(cpu) netif_wake_subqueue(dev, cpu); } /* Ioctl commands. */ static int tile_net_ioctl(struct net_device *dev, struct ifreq *rq, int cmd) { return -EOPNOTSUPP; } /* Get system network statistics for device. */ static struct net_device_stats *tile_net_get_stats(struct net_device *dev) { struct tile_net_priv *priv = netdev_priv(dev); return &priv->stats; } /* Change the MTU. */ static int tile_net_change_mtu(struct net_device *dev, int new_mtu) { if ((new_mtu < 68) || (new_mtu > 1500)) return -EINVAL; dev->mtu = new_mtu; return 0; } /* Change the Ethernet address of the NIC. * * The hypervisor driver does not support changing MAC address. However, * the hardware does not do anything with the MAC address, so the address * which gets used on outgoing packets, and which is accepted on incoming * packets, is completely up to us. * * Returns 0 on success, negative on failure. */ static int tile_net_set_mac_address(struct net_device *dev, void *p) { struct sockaddr *addr = p; if (!is_valid_ether_addr(addr->sa_data)) return -EINVAL; memcpy(dev->dev_addr, addr->sa_data, dev->addr_len); return 0; } #ifdef CONFIG_NET_POLL_CONTROLLER /* Polling 'interrupt' - used by things like netconsole to send skbs * without having to re-enable interrupts. It's not called while * the interrupt routine is executing. */ static void tile_net_netpoll(struct net_device *dev) { disable_percpu_irq(ingress_irq); tile_net_handle_ingress_irq(ingress_irq, NULL); enable_percpu_irq(ingress_irq, 0); } #endif static const struct net_device_ops tile_net_ops = { .ndo_open = tile_net_open, .ndo_stop = tile_net_stop, .ndo_start_xmit = tile_net_tx, .ndo_select_queue = tile_net_select_queue, .ndo_do_ioctl = tile_net_ioctl, .ndo_get_stats = tile_net_get_stats, .ndo_change_mtu = tile_net_change_mtu, .ndo_tx_timeout = tile_net_tx_timeout, .ndo_set_mac_address = tile_net_set_mac_address, #ifdef CONFIG_NET_POLL_CONTROLLER .ndo_poll_controller = tile_net_netpoll, #endif }; /* The setup function. * * This uses ether_setup() to assign various fields in dev, including * setting IFF_BROADCAST and IFF_MULTICAST, then sets some extra fields. */ static void tile_net_setup(struct net_device *dev) { ether_setup(dev); dev->netdev_ops = &tile_net_ops; dev->watchdog_timeo = TILE_NET_TIMEOUT; dev->features |= NETIF_F_LLTX; dev->features |= NETIF_F_HW_CSUM; dev->features |= NETIF_F_SG; dev->features |= NETIF_F_TSO; dev->mtu = 1500; } /* Allocate the device structure, register the device, and obtain the * MAC address from the hypervisor. */ static void tile_net_dev_init(const char *name, const uint8_t *mac) { int ret; int i; int nz_addr = 0; struct net_device *dev; struct tile_net_priv *priv; /* HACK: Ignore "loop" links. */ if (strncmp(name, "loop", 4) == 0) return; /* Allocate the device structure. Normally, "name" is a * template, instantiated by register_netdev(), but not for us. */ dev = alloc_netdev_mqs(sizeof(*priv), name, tile_net_setup, NR_CPUS, 1); if (!dev) { pr_err("alloc_netdev_mqs(%s) failed\n", name); return; } /* Initialize "priv". */ priv = netdev_priv(dev); memset(priv, 0, sizeof(*priv)); priv->dev = dev; priv->channel = -1; priv->loopify_channel = -1; priv->echannel = -1; /* Get the MAC address and set it in the device struct; this must * be done before the device is opened. If the MAC is all zeroes, * we use a random address, since we're probably on the simulator. */ for (i = 0; i < 6; i++) nz_addr |= mac[i]; if (nz_addr) { memcpy(dev->dev_addr, mac, 6); dev->addr_len = 6; } else { eth_hw_addr_random(dev); } /* Register the network device. */ ret = register_netdev(dev); if (ret) { netdev_err(dev, "register_netdev failed %d\n", ret); free_netdev(dev); return; } } /* Per-cpu module initialization. */ static void tile_net_init_module_percpu(void *unused) { struct tile_net_info *info = &__get_cpu_var(per_cpu_info); int my_cpu = smp_processor_id(); info->has_iqueue = false; info->my_cpu = my_cpu; /* Initialize the egress timer. */ hrtimer_init(&info->egress_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL); info->egress_timer.function = tile_net_handle_egress_timer; } /* Module initialization. */ static int __init tile_net_init_module(void) { int i; char name[GXIO_MPIPE_LINK_NAME_LEN]; uint8_t mac[6]; pr_info("Tilera Network Driver\n"); mutex_init(&tile_net_devs_for_channel_mutex); /* Initialize each CPU. */ on_each_cpu(tile_net_init_module_percpu, NULL, 1); /* Find out what devices we have, and initialize them. */ for (i = 0; gxio_mpipe_link_enumerate_mac(i, name, mac) >= 0; i++) tile_net_dev_init(name, mac); if (!network_cpus_init()) network_cpus_map = *cpu_online_mask; return 0; } module_init(tile_net_init_module);