diff options
Diffstat (limited to 'drivers/net/ethernet/tile/tilegx.c')
| -rw-r--r-- | drivers/net/ethernet/tile/tilegx.c | 1908 |
1 files changed, 0 insertions, 1908 deletions
diff --git a/drivers/net/ethernet/tile/tilegx.c b/drivers/net/ethernet/tile/tilegx.c deleted file mode 100644 index f3c2d034b32c..000000000000 --- a/drivers/net/ethernet/tile/tilegx.c +++ /dev/null @@ -1,1908 +0,0 @@ -/* - * 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 <linux/module.h> -#include <linux/init.h> -#include <linux/moduleparam.h> -#include <linux/sched.h> -#include <linux/kernel.h> /* printk() */ -#include <linux/slab.h> /* kmalloc() */ -#include <linux/errno.h> /* error codes */ -#include <linux/types.h> /* size_t */ -#include <linux/interrupt.h> -#include <linux/in.h> -#include <linux/irq.h> -#include <linux/netdevice.h> /* struct device, and other headers */ -#include <linux/etherdevice.h> /* eth_type_trans */ -#include <linux/skbuff.h> -#include <linux/ioctl.h> -#include <linux/cdev.h> -#include <linux/hugetlb.h> -#include <linux/in6.h> -#include <linux/timer.h> -#include <linux/hrtimer.h> -#include <linux/ktime.h> -#include <linux/io.h> -#include <linux/ctype.h> -#include <linux/ip.h> -#include <linux/tcp.h> - -#include <asm/checksum.h> -#include <asm/homecache.h> -#include <gxio/mpipe.h> -#include <arch/sim.h> - -/* 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); |