2 * Copyright 2012 Tilera Corporation. All Rights Reserved.
4 * This program is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU General Public License
6 * as published by the Free Software Foundation, version 2.
8 * This program is distributed in the hope that it will be useful, but
9 * WITHOUT ANY WARRANTY; without even the implied warranty of
10 * MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE, GOOD TITLE or
11 * NON INFRINGEMENT. See the GNU General Public License for
15 #include <linux/module.h>
16 #include <linux/init.h>
17 #include <linux/moduleparam.h>
18 #include <linux/sched.h>
19 #include <linux/kernel.h> /* printk() */
20 #include <linux/slab.h> /* kmalloc() */
21 #include <linux/errno.h> /* error codes */
22 #include <linux/types.h> /* size_t */
23 #include <linux/interrupt.h>
25 #include <linux/irq.h>
26 #include <linux/netdevice.h> /* struct device, and other headers */
27 #include <linux/etherdevice.h> /* eth_type_trans */
28 #include <linux/skbuff.h>
29 #include <linux/ioctl.h>
30 #include <linux/cdev.h>
31 #include <linux/hugetlb.h>
32 #include <linux/in6.h>
33 #include <linux/timer.h>
34 #include <linux/hrtimer.h>
35 #include <linux/ktime.h>
37 #include <linux/ctype.h>
39 #include <linux/tcp.h>
41 #include <asm/checksum.h>
42 #include <asm/homecache.h>
43 #include <gxio/mpipe.h>
46 /* Default transmit lockup timeout period, in jiffies. */
47 #define TILE_NET_TIMEOUT (5 * HZ)
49 /* The maximum number of distinct channels (idesc.channel is 5 bits). */
50 #define TILE_NET_CHANNELS 32
52 /* Maximum number of idescs to handle per "poll". */
53 #define TILE_NET_BATCH 128
55 /* Maximum number of packets to handle per "poll". */
56 #define TILE_NET_WEIGHT 64
58 /* Number of entries in each iqueue. */
59 #define IQUEUE_ENTRIES 512
61 /* Number of entries in each equeue. */
62 #define EQUEUE_ENTRIES 2048
64 /* Total header bytes per equeue slot. Must be big enough for 2 bytes
65 * of NET_IP_ALIGN alignment, plus 14 bytes (?) of L2 header, plus up to
66 * 60 bytes of actual TCP header. We round up to align to cache lines.
68 #define HEADER_BYTES 128
70 /* Maximum completions per cpu per device (must be a power of two).
71 * ISSUE: What is the right number here? If this is too small, then
72 * egress might block waiting for free space in a completions array.
73 * ISSUE: At the least, allocate these only for initialized echannels.
75 #define TILE_NET_MAX_COMPS 64
77 #define MAX_FRAGS (MAX_SKB_FRAGS + 1)
79 /* Size of completions data to allocate.
80 * ISSUE: Probably more than needed since we don't use all the channels.
82 #define COMPS_SIZE (TILE_NET_CHANNELS * sizeof(struct tile_net_comps))
84 /* Size of NotifRing data to allocate. */
85 #define NOTIF_RING_SIZE (IQUEUE_ENTRIES * sizeof(gxio_mpipe_idesc_t))
87 /* Timeout to wake the per-device TX timer after we stop the queue.
88 * We don't want the timeout too short (adds overhead, and might end
89 * up causing stop/wake/stop/wake cycles) or too long (affects performance).
90 * For the 10 Gb NIC, 30 usec means roughly 30+ 1500-byte packets.
92 #define TX_TIMER_DELAY_USEC 30
94 /* Timeout to wake the per-cpu egress timer to free completions. */
95 #define EGRESS_TIMER_DELAY_USEC 1000
97 MODULE_AUTHOR("Tilera Corporation");
98 MODULE_LICENSE("GPL");
100 /* A "packet fragment" (a chunk of memory). */
106 /* A single completion. */
107 struct tile_net_comp {
108 /* The "complete_count" when the completion will be complete. */
110 /* The buffer to be freed when the completion is complete. */
114 /* The completions for a given cpu and echannel. */
115 struct tile_net_comps {
116 /* The completions. */
117 struct tile_net_comp comp_queue[TILE_NET_MAX_COMPS];
118 /* The number of completions used. */
119 unsigned long comp_next;
120 /* The number of completions freed. */
121 unsigned long comp_last;
124 /* The transmit wake timer for a given cpu and echannel. */
125 struct tile_net_tx_wake {
126 struct hrtimer timer;
127 struct net_device *dev;
130 /* Info for a specific cpu. */
131 struct tile_net_info {
132 /* The NAPI struct. */
133 struct napi_struct napi;
135 gxio_mpipe_iqueue_t iqueue;
138 /* True if iqueue is valid. */
143 /* Number of small sk_buffs which must still be provided. */
144 unsigned int num_needed_small_buffers;
145 /* Number of large sk_buffs which must still be provided. */
146 unsigned int num_needed_large_buffers;
147 /* A timer for handling egress completions. */
148 struct hrtimer egress_timer;
149 /* True if "egress_timer" is scheduled. */
150 bool egress_timer_scheduled;
151 /* Comps for each egress channel. */
152 struct tile_net_comps *comps_for_echannel[TILE_NET_CHANNELS];
153 /* Transmit wake timer for each egress channel. */
154 struct tile_net_tx_wake tx_wake[TILE_NET_CHANNELS];
157 /* Info for egress on a particular egress channel. */
158 struct tile_net_egress {
160 gxio_mpipe_equeue_t *equeue;
161 /* The headers for TSO. */
162 unsigned char *headers;
165 /* Info for a specific device. */
166 struct tile_net_priv {
167 /* Our network device. */
168 struct net_device *dev;
169 /* The primary link. */
170 gxio_mpipe_link_t link;
171 /* The primary channel, if open, else -1. */
173 /* The "loopify" egress link, if needed. */
174 gxio_mpipe_link_t loopify_link;
175 /* The "loopify" egress channel, if open, else -1. */
177 /* The egress channel (channel or loopify_channel). */
180 struct net_device_stats stats;
183 /* Egress info, indexed by "priv->echannel" (lazily created as needed). */
184 static struct tile_net_egress egress_for_echannel[TILE_NET_CHANNELS];
186 /* Devices currently associated with each channel.
187 * NOTE: The array entry can become NULL after ifconfig down, but
188 * we do not free the underlying net_device structures, so it is
189 * safe to use a pointer after reading it from this array.
191 static struct net_device *tile_net_devs_for_channel[TILE_NET_CHANNELS];
193 /* A mutex for "tile_net_devs_for_channel". */
194 static DEFINE_MUTEX(tile_net_devs_for_channel_mutex);
196 /* The per-cpu info. */
197 static DEFINE_PER_CPU(struct tile_net_info, per_cpu_info);
199 /* The "context" for all devices. */
200 static gxio_mpipe_context_t context;
202 /* Buffer sizes and mpipe enum codes for buffer stacks.
203 * See arch/tile/include/gxio/mpipe.h for the set of possible values.
205 #define BUFFER_SIZE_SMALL_ENUM GXIO_MPIPE_BUFFER_SIZE_128
206 #define BUFFER_SIZE_SMALL 128
207 #define BUFFER_SIZE_LARGE_ENUM GXIO_MPIPE_BUFFER_SIZE_1664
208 #define BUFFER_SIZE_LARGE 1664
210 /* The small/large "buffer stacks". */
211 static int small_buffer_stack = -1;
212 static int large_buffer_stack = -1;
214 /* Amount of memory allocated for each buffer stack. */
215 static size_t buffer_stack_size;
217 /* The actual memory allocated for the buffer stacks. */
218 static void *small_buffer_stack_va;
219 static void *large_buffer_stack_va;
222 static int first_bucket = -1;
223 static int num_buckets = 1;
225 /* The ingress irq. */
226 static int ingress_irq = -1;
228 /* Text value of tile_net.cpus if passed as a module parameter. */
229 static char *network_cpus_string;
231 /* The actual cpus in "network_cpus". */
232 static struct cpumask network_cpus_map;
234 /* If "loopify=LINK" was specified, this is "LINK". */
235 static char *loopify_link_name;
237 /* If "tile_net.custom" was specified, this is non-NULL. */
238 static char *custom_str;
240 /* The "tile_net.cpus" argument specifies the cpus that are dedicated
241 * to handle ingress packets.
243 * The parameter should be in the form "tile_net.cpus=m-n[,x-y]", where
244 * m, n, x, y are integer numbers that represent the cpus that can be
245 * neither a dedicated cpu nor a dataplane cpu.
247 static bool network_cpus_init(void)
252 if (network_cpus_string == NULL)
255 rc = cpulist_parse_crop(network_cpus_string, &network_cpus_map);
257 pr_warn("tile_net.cpus=%s: malformed cpu list\n",
258 network_cpus_string);
262 /* Remove dedicated cpus. */
263 cpumask_and(&network_cpus_map, &network_cpus_map, cpu_possible_mask);
265 if (cpumask_empty(&network_cpus_map)) {
266 pr_warn("Ignoring empty tile_net.cpus='%s'.\n",
267 network_cpus_string);
271 cpulist_scnprintf(buf, sizeof(buf), &network_cpus_map);
272 pr_info("Linux network CPUs: %s\n", buf);
276 module_param_named(cpus, network_cpus_string, charp, 0444);
277 MODULE_PARM_DESC(cpus, "cpulist of cores that handle network interrupts");
279 /* The "tile_net.loopify=LINK" argument causes the named device to
280 * actually use "loop0" for ingress, and "loop1" for egress. This
281 * allows an app to sit between the actual link and linux, passing
282 * (some) packets along to linux, and forwarding (some) packets sent
285 module_param_named(loopify, loopify_link_name, charp, 0444);
286 MODULE_PARM_DESC(loopify, "name the device to use loop0/1 for ingress/egress");
288 /* The "tile_net.custom" argument causes us to ignore the "conventional"
289 * classifier metadata, in particular, the "l2_offset".
291 module_param_named(custom, custom_str, charp, 0444);
292 MODULE_PARM_DESC(custom, "indicates a (heavily) customized classifier");
294 /* Atomically update a statistics field.
295 * Note that on TILE-Gx, this operation is fire-and-forget on the
296 * issuing core (single-cycle dispatch) and takes only a few cycles
297 * longer than a regular store when the request reaches the home cache.
298 * No expensive bus management overhead is required.
300 static void tile_net_stats_add(unsigned long value, unsigned long *field)
302 BUILD_BUG_ON(sizeof(atomic_long_t) != sizeof(unsigned long));
303 atomic_long_add(value, (atomic_long_t *)field);
306 /* Allocate and push a buffer. */
307 static bool tile_net_provide_buffer(bool small)
309 int stack = small ? small_buffer_stack : large_buffer_stack;
310 const unsigned long buffer_alignment = 128;
314 len = sizeof(struct sk_buff **) + buffer_alignment;
315 len += (small ? BUFFER_SIZE_SMALL : BUFFER_SIZE_LARGE);
316 skb = dev_alloc_skb(len);
320 /* Make room for a back-pointer to 'skb' and guarantee alignment. */
321 skb_reserve(skb, sizeof(struct sk_buff **));
322 skb_reserve(skb, -(long)skb->data & (buffer_alignment - 1));
324 /* Save a back-pointer to 'skb'. */
325 *(struct sk_buff **)(skb->data - sizeof(struct sk_buff **)) = skb;
327 /* Make sure "skb" and the back-pointer have been flushed. */
330 gxio_mpipe_push_buffer(&context, stack,
331 (void *)va_to_tile_io_addr(skb->data));
336 /* Convert a raw mpipe buffer to its matching skb pointer. */
337 static struct sk_buff *mpipe_buf_to_skb(void *va)
339 /* Acquire the associated "skb". */
340 struct sk_buff **skb_ptr = va - sizeof(*skb_ptr);
341 struct sk_buff *skb = *skb_ptr;
344 if (skb->data != va) {
345 /* Panic here since there's a reasonable chance
346 * that corrupt buffers means generic memory
347 * corruption, with unpredictable system effects.
349 panic("Corrupt linux buffer! va=%p, skb=%p, skb->data=%p",
356 static void tile_net_pop_all_buffers(int stack)
359 tile_io_addr_t addr =
360 (tile_io_addr_t)gxio_mpipe_pop_buffer(&context, stack);
363 dev_kfree_skb_irq(mpipe_buf_to_skb(tile_io_addr_to_va(addr)));
367 /* Provide linux buffers to mPIPE. */
368 static void tile_net_provide_needed_buffers(void)
370 struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
372 while (info->num_needed_small_buffers != 0) {
373 if (!tile_net_provide_buffer(true))
375 info->num_needed_small_buffers--;
378 while (info->num_needed_large_buffers != 0) {
379 if (!tile_net_provide_buffer(false))
381 info->num_needed_large_buffers--;
387 /* Add a description to the page allocation failure dump. */
388 pr_notice("Tile %d still needs some buffers\n", info->my_cpu);
391 static inline bool filter_packet(struct net_device *dev, void *buf)
393 /* Filter packets received before we're up. */
394 if (dev == NULL || !(dev->flags & IFF_UP))
397 /* Filter out packets that aren't for us. */
398 if (!(dev->flags & IFF_PROMISC) &&
399 !is_multicast_ether_addr(buf) &&
400 compare_ether_addr(dev->dev_addr, buf) != 0)
406 static void tile_net_receive_skb(struct net_device *dev, struct sk_buff *skb,
407 gxio_mpipe_idesc_t *idesc, unsigned long len)
409 struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
410 struct tile_net_priv *priv = netdev_priv(dev);
412 /* Encode the actual packet length. */
415 skb->protocol = eth_type_trans(skb, dev);
417 /* Acknowledge "good" hardware checksums. */
418 if (idesc->cs && idesc->csum_seed_val == 0xFFFF)
419 skb->ip_summed = CHECKSUM_UNNECESSARY;
421 netif_receive_skb(skb);
424 tile_net_stats_add(1, &priv->stats.rx_packets);
425 tile_net_stats_add(len, &priv->stats.rx_bytes);
427 /* Need a new buffer. */
428 if (idesc->size == BUFFER_SIZE_SMALL_ENUM)
429 info->num_needed_small_buffers++;
431 info->num_needed_large_buffers++;
434 /* Handle a packet. Return true if "processed", false if "filtered". */
435 static bool tile_net_handle_packet(gxio_mpipe_idesc_t *idesc)
437 struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
438 struct net_device *dev = tile_net_devs_for_channel[idesc->channel];
445 /* Drop packets for which no buffer was available.
446 * NOTE: This happens under heavy load.
449 struct tile_net_priv *priv = netdev_priv(dev);
450 tile_net_stats_add(1, &priv->stats.rx_dropped);
451 gxio_mpipe_iqueue_consume(&info->iqueue, idesc);
453 pr_info("Dropping packet (insufficient buffers).\n");
457 /* Get the "l2_offset", if allowed. */
458 l2_offset = custom_str ? 0 : gxio_mpipe_idesc_get_l2_offset(idesc);
460 /* Get the raw buffer VA (includes "headroom"). */
461 va = tile_io_addr_to_va((unsigned long)(long)idesc->va);
463 /* Get the actual packet start/length. */
464 buf = va + l2_offset;
465 len = idesc->l2_size - l2_offset;
467 /* Point "va" at the raw buffer. */
470 filter = filter_packet(dev, buf);
472 gxio_mpipe_iqueue_drop(&info->iqueue, idesc);
474 struct sk_buff *skb = mpipe_buf_to_skb(va);
476 /* Skip headroom, and any custom header. */
477 skb_reserve(skb, NET_IP_ALIGN + l2_offset);
479 tile_net_receive_skb(dev, skb, idesc, len);
482 gxio_mpipe_iqueue_consume(&info->iqueue, idesc);
486 /* Handle some packets for the current CPU.
488 * This function handles up to TILE_NET_BATCH idescs per call.
490 * ISSUE: Since we do not provide new buffers until this function is
491 * complete, we must initially provide enough buffers for each network
492 * cpu to fill its iqueue and also its batched idescs.
494 * ISSUE: The "rotting packet" race condition occurs if a packet
495 * arrives after the queue appears to be empty, and before the
496 * hypervisor interrupt is re-enabled.
498 static int tile_net_poll(struct napi_struct *napi, int budget)
500 struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
501 unsigned int work = 0;
502 gxio_mpipe_idesc_t *idesc;
505 /* Process packets. */
506 while ((n = gxio_mpipe_iqueue_try_peek(&info->iqueue, &idesc)) > 0) {
507 for (i = 0; i < n; i++) {
508 if (i == TILE_NET_BATCH)
510 if (tile_net_handle_packet(idesc + i)) {
511 if (++work >= budget)
517 /* There are no packets left. */
518 napi_complete(&info->napi);
520 /* Re-enable hypervisor interrupts. */
521 gxio_mpipe_enable_notif_ring_interrupt(&context, info->iqueue.ring);
523 /* HACK: Avoid the "rotting packet" problem. */
524 if (gxio_mpipe_iqueue_try_peek(&info->iqueue, &idesc) > 0)
525 napi_schedule(&info->napi);
527 /* ISSUE: Handle completions? */
530 tile_net_provide_needed_buffers();
535 /* Handle an ingress interrupt on the current cpu. */
536 static irqreturn_t tile_net_handle_ingress_irq(int irq, void *unused)
538 struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
539 napi_schedule(&info->napi);
543 /* Free some completions. This must be called with interrupts blocked. */
544 static int tile_net_free_comps(gxio_mpipe_equeue_t *equeue,
545 struct tile_net_comps *comps,
546 int limit, bool force_update)
549 while (comps->comp_last < comps->comp_next) {
550 unsigned int cid = comps->comp_last % TILE_NET_MAX_COMPS;
551 struct tile_net_comp *comp = &comps->comp_queue[cid];
552 if (!gxio_mpipe_equeue_is_complete(equeue, comp->when,
553 force_update || n == 0))
555 dev_kfree_skb_irq(comp->skb);
563 /* Add a completion. This must be called with interrupts blocked.
564 * tile_net_equeue_try_reserve() will have ensured a free completion entry.
566 static void add_comp(gxio_mpipe_equeue_t *equeue,
567 struct tile_net_comps *comps,
568 uint64_t when, struct sk_buff *skb)
570 int cid = comps->comp_next % TILE_NET_MAX_COMPS;
571 comps->comp_queue[cid].when = when;
572 comps->comp_queue[cid].skb = skb;
576 static void tile_net_schedule_tx_wake_timer(struct net_device *dev)
578 struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
579 struct tile_net_priv *priv = netdev_priv(dev);
581 hrtimer_start(&info->tx_wake[priv->echannel].timer,
582 ktime_set(0, TX_TIMER_DELAY_USEC * 1000UL),
583 HRTIMER_MODE_REL_PINNED);
586 static enum hrtimer_restart tile_net_handle_tx_wake_timer(struct hrtimer *t)
588 struct tile_net_tx_wake *tx_wake =
589 container_of(t, struct tile_net_tx_wake, timer);
590 netif_wake_subqueue(tx_wake->dev, smp_processor_id());
591 return HRTIMER_NORESTART;
594 /* Make sure the egress timer is scheduled. */
595 static void tile_net_schedule_egress_timer(void)
597 struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
599 if (!info->egress_timer_scheduled) {
600 hrtimer_start(&info->egress_timer,
601 ktime_set(0, EGRESS_TIMER_DELAY_USEC * 1000UL),
602 HRTIMER_MODE_REL_PINNED);
603 info->egress_timer_scheduled = true;
607 /* The "function" for "info->egress_timer".
609 * This timer will reschedule itself as long as there are any pending
610 * completions expected for this tile.
612 static enum hrtimer_restart tile_net_handle_egress_timer(struct hrtimer *t)
614 struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
615 unsigned long irqflags;
616 bool pending = false;
619 local_irq_save(irqflags);
621 /* The timer is no longer scheduled. */
622 info->egress_timer_scheduled = false;
624 /* Free all possible comps for this tile. */
625 for (i = 0; i < TILE_NET_CHANNELS; i++) {
626 struct tile_net_egress *egress = &egress_for_echannel[i];
627 struct tile_net_comps *comps = info->comps_for_echannel[i];
628 if (comps->comp_last >= comps->comp_next)
630 tile_net_free_comps(egress->equeue, comps, -1, true);
631 pending = pending || (comps->comp_last < comps->comp_next);
634 /* Reschedule timer if needed. */
636 tile_net_schedule_egress_timer();
638 local_irq_restore(irqflags);
640 return HRTIMER_NORESTART;
643 /* Helper function for "tile_net_update()".
644 * "dev" (i.e. arg) is the device being brought up or down,
645 * or NULL if all devices are now down.
647 static void tile_net_update_cpu(void *arg)
649 struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
650 struct net_device *dev = arg;
652 if (!info->has_iqueue)
656 if (!info->napi_added) {
657 netif_napi_add(dev, &info->napi,
658 tile_net_poll, TILE_NET_WEIGHT);
659 info->napi_added = true;
661 if (!info->napi_enabled) {
662 napi_enable(&info->napi);
663 info->napi_enabled = true;
665 enable_percpu_irq(ingress_irq, 0);
667 disable_percpu_irq(ingress_irq);
668 if (info->napi_enabled) {
669 napi_disable(&info->napi);
670 info->napi_enabled = false;
672 /* FIXME: Drain the iqueue. */
676 /* Helper function for tile_net_open() and tile_net_stop().
677 * Always called under tile_net_devs_for_channel_mutex.
679 static int tile_net_update(struct net_device *dev)
681 static gxio_mpipe_rules_t rules; /* too big to fit on the stack */
682 bool saw_channel = false;
687 gxio_mpipe_rules_init(&rules, &context);
689 for (channel = 0; channel < TILE_NET_CHANNELS; channel++) {
690 if (tile_net_devs_for_channel[channel] == NULL)
694 gxio_mpipe_rules_begin(&rules, first_bucket,
696 gxio_mpipe_rules_set_headroom(&rules, NET_IP_ALIGN);
698 gxio_mpipe_rules_add_channel(&rules, channel);
701 /* NOTE: This can fail if there is no classifier.
702 * ISSUE: Can anything else cause it to fail?
704 rc = gxio_mpipe_rules_commit(&rules);
706 netdev_warn(dev, "gxio_mpipe_rules_commit failed: %d\n", rc);
710 /* Update all cpus, sequentially (to protect "netif_napi_add()"). */
711 for_each_online_cpu(cpu)
712 smp_call_function_single(cpu, tile_net_update_cpu,
713 (saw_channel ? dev : NULL), 1);
715 /* HACK: Allow packets to flow in the simulator. */
717 sim_enable_mpipe_links(0, -1);
722 /* Allocate and initialize mpipe buffer stacks, and register them in
723 * the mPIPE TLBs, for both small and large packet sizes.
724 * This routine supports tile_net_init_mpipe(), below.
726 static int init_buffer_stacks(struct net_device *dev, int num_buffers)
728 pte_t hash_pte = pte_set_home((pte_t) { 0 }, PAGE_HOME_HASH);
731 /* Compute stack bytes; we round up to 64KB and then use
732 * alloc_pages() so we get the required 64KB alignment as well.
735 ALIGN(gxio_mpipe_calc_buffer_stack_bytes(num_buffers),
738 /* Allocate two buffer stack indices. */
739 rc = gxio_mpipe_alloc_buffer_stacks(&context, 2, 0, 0);
741 netdev_err(dev, "gxio_mpipe_alloc_buffer_stacks failed: %d\n",
745 small_buffer_stack = rc;
746 large_buffer_stack = rc + 1;
748 /* Allocate the small memory stack. */
749 small_buffer_stack_va =
750 alloc_pages_exact(buffer_stack_size, GFP_KERNEL);
751 if (small_buffer_stack_va == NULL) {
753 "Could not alloc %zd bytes for buffer stacks\n",
757 rc = gxio_mpipe_init_buffer_stack(&context, small_buffer_stack,
758 BUFFER_SIZE_SMALL_ENUM,
759 small_buffer_stack_va,
760 buffer_stack_size, 0);
762 netdev_err(dev, "gxio_mpipe_init_buffer_stack: %d\n", rc);
765 rc = gxio_mpipe_register_client_memory(&context, small_buffer_stack,
769 "gxio_mpipe_register_buffer_memory failed: %d\n",
774 /* Allocate the large buffer stack. */
775 large_buffer_stack_va =
776 alloc_pages_exact(buffer_stack_size, GFP_KERNEL);
777 if (large_buffer_stack_va == NULL) {
779 "Could not alloc %zd bytes for buffer stacks\n",
783 rc = gxio_mpipe_init_buffer_stack(&context, large_buffer_stack,
784 BUFFER_SIZE_LARGE_ENUM,
785 large_buffer_stack_va,
786 buffer_stack_size, 0);
788 netdev_err(dev, "gxio_mpipe_init_buffer_stack failed: %d\n",
792 rc = gxio_mpipe_register_client_memory(&context, large_buffer_stack,
796 "gxio_mpipe_register_buffer_memory failed: %d\n",
804 /* Allocate per-cpu resources (memory for completions and idescs).
805 * This routine supports tile_net_init_mpipe(), below.
807 static int alloc_percpu_mpipe_resources(struct net_device *dev,
810 struct tile_net_info *info = &per_cpu(per_cpu_info, cpu);
815 /* Allocate the "comps". */
816 order = get_order(COMPS_SIZE);
817 page = homecache_alloc_pages(GFP_KERNEL, order, cpu);
819 netdev_err(dev, "Failed to alloc %zd bytes comps memory\n",
823 addr = pfn_to_kaddr(page_to_pfn(page));
824 memset(addr, 0, COMPS_SIZE);
825 for (i = 0; i < TILE_NET_CHANNELS; i++)
826 info->comps_for_echannel[i] =
827 addr + i * sizeof(struct tile_net_comps);
829 /* If this is a network cpu, create an iqueue. */
830 if (cpu_isset(cpu, network_cpus_map)) {
831 order = get_order(NOTIF_RING_SIZE);
832 page = homecache_alloc_pages(GFP_KERNEL, order, cpu);
835 "Failed to alloc %zd bytes iqueue memory\n",
839 addr = pfn_to_kaddr(page_to_pfn(page));
840 rc = gxio_mpipe_iqueue_init(&info->iqueue, &context, ring++,
841 addr, NOTIF_RING_SIZE, 0);
844 "gxio_mpipe_iqueue_init failed: %d\n", rc);
847 info->has_iqueue = true;
853 /* Initialize NotifGroup and buckets.
854 * This routine supports tile_net_init_mpipe(), below.
856 static int init_notif_group_and_buckets(struct net_device *dev,
857 int ring, int network_cpus_count)
861 /* Allocate one NotifGroup. */
862 rc = gxio_mpipe_alloc_notif_groups(&context, 1, 0, 0);
864 netdev_err(dev, "gxio_mpipe_alloc_notif_groups failed: %d\n",
870 /* Initialize global num_buckets value. */
871 if (network_cpus_count > 4)
873 else if (network_cpus_count > 1)
876 /* Allocate some buckets, and set global first_bucket value. */
877 rc = gxio_mpipe_alloc_buckets(&context, num_buckets, 0, 0);
879 netdev_err(dev, "gxio_mpipe_alloc_buckets failed: %d\n", rc);
884 /* Init group and buckets. */
885 rc = gxio_mpipe_init_notif_group_and_buckets(
886 &context, group, ring, network_cpus_count,
887 first_bucket, num_buckets,
888 GXIO_MPIPE_BUCKET_STICKY_FLOW_LOCALITY);
892 "gxio_mpipe_init_notif_group_and_buckets failed: %d\n",
900 /* Create an irq and register it, then activate the irq and request
901 * interrupts on all cores. Note that "ingress_irq" being initialized
902 * is how we know not to call tile_net_init_mpipe() again.
903 * This routine supports tile_net_init_mpipe(), below.
905 static int tile_net_setup_interrupts(struct net_device *dev)
911 netdev_err(dev, "create_irq failed: %d\n", rc);
915 tile_irq_activate(ingress_irq, TILE_IRQ_PERCPU);
916 rc = request_irq(ingress_irq, tile_net_handle_ingress_irq,
919 netdev_err(dev, "request_irq failed: %d\n", rc);
920 destroy_irq(ingress_irq);
925 for_each_online_cpu(cpu) {
926 struct tile_net_info *info = &per_cpu(per_cpu_info, cpu);
927 if (info->has_iqueue) {
928 gxio_mpipe_request_notif_ring_interrupt(
929 &context, cpu_x(cpu), cpu_y(cpu),
930 1, ingress_irq, info->iqueue.ring);
937 /* Undo any state set up partially by a failed call to tile_net_init_mpipe. */
938 static void tile_net_init_mpipe_fail(void)
942 /* Do cleanups that require the mpipe context first. */
943 if (small_buffer_stack >= 0)
944 tile_net_pop_all_buffers(small_buffer_stack);
945 if (large_buffer_stack >= 0)
946 tile_net_pop_all_buffers(large_buffer_stack);
948 /* Destroy mpipe context so the hardware no longer owns any memory. */
949 gxio_mpipe_destroy(&context);
951 for_each_online_cpu(cpu) {
952 struct tile_net_info *info = &per_cpu(per_cpu_info, cpu);
953 free_pages((unsigned long)(info->comps_for_echannel[0]),
954 get_order(COMPS_SIZE));
955 info->comps_for_echannel[0] = NULL;
956 free_pages((unsigned long)(info->iqueue.idescs),
957 get_order(NOTIF_RING_SIZE));
958 info->iqueue.idescs = NULL;
961 if (small_buffer_stack_va)
962 free_pages_exact(small_buffer_stack_va, buffer_stack_size);
963 if (large_buffer_stack_va)
964 free_pages_exact(large_buffer_stack_va, buffer_stack_size);
966 small_buffer_stack_va = NULL;
967 large_buffer_stack_va = NULL;
968 large_buffer_stack = -1;
969 small_buffer_stack = -1;
973 /* The first time any tilegx network device is opened, we initialize
974 * the global mpipe state. If this step fails, we fail to open the
975 * device, but if it succeeds, we never need to do it again, and since
976 * tile_net can't be unloaded, we never undo it.
978 * Note that some resources in this path (buffer stack indices,
979 * bindings from init_buffer_stack, etc.) are hypervisor resources
980 * that are freed implicitly by gxio_mpipe_destroy().
982 static int tile_net_init_mpipe(struct net_device *dev)
984 int i, num_buffers, rc;
986 int first_ring, ring;
987 int network_cpus_count = cpus_weight(network_cpus_map);
990 netdev_err(dev, "Networking requires hash_default!\n");
994 rc = gxio_mpipe_init(&context, 0);
996 netdev_err(dev, "gxio_mpipe_init failed: %d\n", rc);
1000 /* Set up the buffer stacks. */
1002 network_cpus_count * (IQUEUE_ENTRIES + TILE_NET_BATCH);
1003 rc = init_buffer_stacks(dev, num_buffers);
1007 /* Provide initial buffers. */
1009 for (i = 0; i < num_buffers; i++) {
1010 if (!tile_net_provide_buffer(true)) {
1011 netdev_err(dev, "Cannot allocate initial sk_bufs!\n");
1015 for (i = 0; i < num_buffers; i++) {
1016 if (!tile_net_provide_buffer(false)) {
1017 netdev_err(dev, "Cannot allocate initial sk_bufs!\n");
1022 /* Allocate one NotifRing for each network cpu. */
1023 rc = gxio_mpipe_alloc_notif_rings(&context, network_cpus_count, 0, 0);
1025 netdev_err(dev, "gxio_mpipe_alloc_notif_rings failed %d\n",
1030 /* Init NotifRings per-cpu. */
1033 for_each_online_cpu(cpu) {
1034 rc = alloc_percpu_mpipe_resources(dev, cpu, ring);
1040 /* Initialize NotifGroup and buckets. */
1041 rc = init_notif_group_and_buckets(dev, first_ring, network_cpus_count);
1045 /* Create and enable interrupts. */
1046 rc = tile_net_setup_interrupts(dev);
1053 tile_net_init_mpipe_fail();
1057 /* Create persistent egress info for a given egress channel.
1058 * Note that this may be shared between, say, "gbe0" and "xgbe0".
1059 * ISSUE: Defer header allocation until TSO is actually needed?
1061 static int tile_net_init_egress(struct net_device *dev, int echannel)
1063 struct page *headers_page, *edescs_page, *equeue_page;
1064 gxio_mpipe_edesc_t *edescs;
1065 gxio_mpipe_equeue_t *equeue;
1066 unsigned char *headers;
1067 int headers_order, edescs_order, equeue_order;
1072 /* Only initialize once. */
1073 if (egress_for_echannel[echannel].equeue != NULL)
1076 /* Allocate memory for the "headers". */
1077 headers_order = get_order(EQUEUE_ENTRIES * HEADER_BYTES);
1078 headers_page = alloc_pages(GFP_KERNEL, headers_order);
1079 if (headers_page == NULL) {
1081 "Could not alloc %zd bytes for TSO headers.\n",
1082 PAGE_SIZE << headers_order);
1085 headers = pfn_to_kaddr(page_to_pfn(headers_page));
1087 /* Allocate memory for the "edescs". */
1088 edescs_size = EQUEUE_ENTRIES * sizeof(*edescs);
1089 edescs_order = get_order(edescs_size);
1090 edescs_page = alloc_pages(GFP_KERNEL, edescs_order);
1091 if (edescs_page == NULL) {
1093 "Could not alloc %zd bytes for eDMA ring.\n",
1097 edescs = pfn_to_kaddr(page_to_pfn(edescs_page));
1099 /* Allocate memory for the "equeue". */
1100 equeue_order = get_order(sizeof(*equeue));
1101 equeue_page = alloc_pages(GFP_KERNEL, equeue_order);
1102 if (equeue_page == NULL) {
1104 "Could not alloc %zd bytes for equeue info.\n",
1105 PAGE_SIZE << equeue_order);
1108 equeue = pfn_to_kaddr(page_to_pfn(equeue_page));
1110 /* Allocate an edma ring. Note that in practice this can't
1111 * fail, which is good, because we will leak an edma ring if so.
1113 rc = gxio_mpipe_alloc_edma_rings(&context, 1, 0, 0);
1115 netdev_warn(dev, "gxio_mpipe_alloc_edma_rings failed: %d\n",
1121 /* Initialize the equeue. */
1122 rc = gxio_mpipe_equeue_init(equeue, &context, edma, echannel,
1123 edescs, edescs_size, 0);
1125 netdev_err(dev, "gxio_mpipe_equeue_init failed: %d\n", rc);
1130 egress_for_echannel[echannel].equeue = equeue;
1131 egress_for_echannel[echannel].headers = headers;
1135 __free_pages(equeue_page, equeue_order);
1138 __free_pages(edescs_page, edescs_order);
1141 __free_pages(headers_page, headers_order);
1147 /* Return channel number for a newly-opened link. */
1148 static int tile_net_link_open(struct net_device *dev, gxio_mpipe_link_t *link,
1149 const char *link_name)
1151 int rc = gxio_mpipe_link_open(link, &context, link_name, 0);
1153 netdev_err(dev, "Failed to open '%s'\n", link_name);
1156 rc = gxio_mpipe_link_channel(link);
1157 if (rc < 0 || rc >= TILE_NET_CHANNELS) {
1158 netdev_err(dev, "gxio_mpipe_link_channel bad value: %d\n", rc);
1159 gxio_mpipe_link_close(link);
1165 /* Help the kernel activate the given network interface. */
1166 static int tile_net_open(struct net_device *dev)
1168 struct tile_net_priv *priv = netdev_priv(dev);
1171 mutex_lock(&tile_net_devs_for_channel_mutex);
1173 /* Do one-time initialization the first time any device is opened. */
1174 if (ingress_irq < 0) {
1175 rc = tile_net_init_mpipe(dev);
1180 /* Determine if this is the "loopify" device. */
1181 if (unlikely((loopify_link_name != NULL) &&
1182 !strcmp(dev->name, loopify_link_name))) {
1183 rc = tile_net_link_open(dev, &priv->link, "loop0");
1187 rc = tile_net_link_open(dev, &priv->loopify_link, "loop1");
1190 priv->loopify_channel = rc;
1191 priv->echannel = rc;
1193 rc = tile_net_link_open(dev, &priv->link, dev->name);
1197 priv->echannel = rc;
1200 /* Initialize egress info (if needed). Once ever, per echannel. */
1201 rc = tile_net_init_egress(dev, priv->echannel);
1205 tile_net_devs_for_channel[priv->channel] = dev;
1207 rc = tile_net_update(dev);
1211 mutex_unlock(&tile_net_devs_for_channel_mutex);
1213 /* Initialize the transmit wake timer for this device for each cpu. */
1214 for_each_online_cpu(cpu) {
1215 struct tile_net_info *info = &per_cpu(per_cpu_info, cpu);
1216 struct tile_net_tx_wake *tx_wake =
1217 &info->tx_wake[priv->echannel];
1219 hrtimer_init(&tx_wake->timer, CLOCK_MONOTONIC,
1221 tx_wake->timer.function = tile_net_handle_tx_wake_timer;
1225 for_each_online_cpu(cpu)
1226 netif_start_subqueue(dev, cpu);
1227 netif_carrier_on(dev);
1231 if (priv->loopify_channel >= 0) {
1232 if (gxio_mpipe_link_close(&priv->loopify_link) != 0)
1233 netdev_warn(dev, "Failed to close loopify link!\n");
1234 priv->loopify_channel = -1;
1236 if (priv->channel >= 0) {
1237 if (gxio_mpipe_link_close(&priv->link) != 0)
1238 netdev_warn(dev, "Failed to close link!\n");
1241 priv->echannel = -1;
1242 tile_net_devs_for_channel[priv->channel] = NULL;
1243 mutex_unlock(&tile_net_devs_for_channel_mutex);
1245 /* Don't return raw gxio error codes to generic Linux. */
1246 return (rc > -512) ? rc : -EIO;
1249 /* Help the kernel deactivate the given network interface. */
1250 static int tile_net_stop(struct net_device *dev)
1252 struct tile_net_priv *priv = netdev_priv(dev);
1255 for_each_online_cpu(cpu) {
1256 struct tile_net_info *info = &per_cpu(per_cpu_info, cpu);
1257 struct tile_net_tx_wake *tx_wake =
1258 &info->tx_wake[priv->echannel];
1260 hrtimer_cancel(&tx_wake->timer);
1261 netif_stop_subqueue(dev, cpu);
1264 mutex_lock(&tile_net_devs_for_channel_mutex);
1265 tile_net_devs_for_channel[priv->channel] = NULL;
1266 (void)tile_net_update(dev);
1267 if (priv->loopify_channel >= 0) {
1268 if (gxio_mpipe_link_close(&priv->loopify_link) != 0)
1269 netdev_warn(dev, "Failed to close loopify link!\n");
1270 priv->loopify_channel = -1;
1272 if (priv->channel >= 0) {
1273 if (gxio_mpipe_link_close(&priv->link) != 0)
1274 netdev_warn(dev, "Failed to close link!\n");
1277 priv->echannel = -1;
1278 mutex_unlock(&tile_net_devs_for_channel_mutex);
1283 /* Determine the VA for a fragment. */
1284 static inline void *tile_net_frag_buf(skb_frag_t *f)
1286 unsigned long pfn = page_to_pfn(skb_frag_page(f));
1287 return pfn_to_kaddr(pfn) + f->page_offset;
1290 /* Acquire a completion entry and an egress slot, or if we can't,
1291 * stop the queue and schedule the tx_wake timer.
1293 static s64 tile_net_equeue_try_reserve(struct net_device *dev,
1294 struct tile_net_comps *comps,
1295 gxio_mpipe_equeue_t *equeue,
1298 /* Try to acquire a completion entry. */
1299 if (comps->comp_next - comps->comp_last < TILE_NET_MAX_COMPS - 1 ||
1300 tile_net_free_comps(equeue, comps, 32, false) != 0) {
1302 /* Try to acquire an egress slot. */
1303 s64 slot = gxio_mpipe_equeue_try_reserve(equeue, num_edescs);
1307 /* Freeing some completions gives the equeue time to drain. */
1308 tile_net_free_comps(equeue, comps, TILE_NET_MAX_COMPS, false);
1310 slot = gxio_mpipe_equeue_try_reserve(equeue, num_edescs);
1315 /* Still nothing; give up and stop the queue for a short while. */
1316 netif_stop_subqueue(dev, smp_processor_id());
1317 tile_net_schedule_tx_wake_timer(dev);
1321 /* Determine how many edesc's are needed for TSO.
1323 * Sometimes, if "sendfile()" requires copying, we will be called with
1324 * "data" containing the header and payload, with "frags" being empty.
1325 * Sometimes, for example when using NFS over TCP, a single segment can
1326 * span 3 fragments. This requires special care.
1328 static int tso_count_edescs(struct sk_buff *skb)
1330 struct skb_shared_info *sh = skb_shinfo(skb);
1331 unsigned int data_len = skb->data_len;
1332 unsigned int p_len = sh->gso_size;
1333 long f_id = -1; /* id of the current fragment */
1334 long f_size = -1; /* size of the current fragment */
1335 long f_used = -1; /* bytes used from the current fragment */
1336 long n; /* size of the current piece of payload */
1340 for (segment = 0; segment < sh->gso_segs; segment++) {
1342 unsigned int p_used = 0;
1344 /* One edesc for header and for each piece of the payload. */
1345 for (num_edescs++; p_used < p_len; num_edescs++) {
1347 /* Advance as needed. */
1348 while (f_used >= f_size) {
1350 f_size = sh->frags[f_id].size;
1354 /* Use bytes from the current fragment. */
1356 if (n > f_size - f_used)
1357 n = f_size - f_used;
1362 /* The last segment may be less than gso_size. */
1364 if (data_len < p_len)
1371 /* Prepare modified copies of the skbuff headers.
1372 * FIXME: add support for IPv6.
1374 static void tso_headers_prepare(struct sk_buff *skb, unsigned char *headers,
1377 struct skb_shared_info *sh = skb_shinfo(skb);
1380 unsigned int data_len = skb->data_len;
1381 unsigned char *data = skb->data;
1382 unsigned int ih_off, th_off, sh_len, p_len;
1383 unsigned int isum_seed, tsum_seed, id, seq;
1384 long f_id = -1; /* id of the current fragment */
1385 long f_size = -1; /* size of the current fragment */
1386 long f_used = -1; /* bytes used from the current fragment */
1387 long n; /* size of the current piece of payload */
1390 /* Locate original headers and compute various lengths. */
1393 ih_off = skb_network_offset(skb);
1394 th_off = skb_transport_offset(skb);
1395 sh_len = th_off + tcp_hdrlen(skb);
1396 p_len = sh->gso_size;
1398 /* Set up seed values for IP and TCP csum and initialize id and seq. */
1399 isum_seed = ((0xFFFF - ih->check) +
1400 (0xFFFF - ih->tot_len) +
1402 tsum_seed = th->check + (0xFFFF ^ htons(skb->len));
1404 seq = ntohl(th->seq);
1406 /* Prepare all the headers. */
1407 for (segment = 0; segment < sh->gso_segs; segment++) {
1409 unsigned int p_used = 0;
1411 /* Copy to the header memory for this segment. */
1412 buf = headers + (slot % EQUEUE_ENTRIES) * HEADER_BYTES +
1414 memcpy(buf, data, sh_len);
1416 /* Update copied ip header. */
1417 ih = (struct iphdr *)(buf + ih_off);
1418 ih->tot_len = htons(sh_len + p_len - ih_off);
1420 ih->check = csum_long(isum_seed + ih->tot_len +
1423 /* Update copied tcp header. */
1424 th = (struct tcphdr *)(buf + th_off);
1425 th->seq = htonl(seq);
1426 th->check = csum_long(tsum_seed + htons(sh_len + p_len));
1427 if (segment != sh->gso_segs - 1) {
1432 /* Skip past the header. */
1435 /* Skip past the payload. */
1436 while (p_used < p_len) {
1438 /* Advance as needed. */
1439 while (f_used >= f_size) {
1441 f_size = sh->frags[f_id].size;
1445 /* Use bytes from the current fragment. */
1447 if (n > f_size - f_used)
1448 n = f_size - f_used;
1458 /* The last segment may be less than gso_size. */
1460 if (data_len < p_len)
1464 /* Flush the headers so they are ready for hardware DMA. */
1468 /* Pass all the data to mpipe for egress. */
1469 static void tso_egress(struct net_device *dev, gxio_mpipe_equeue_t *equeue,
1470 struct sk_buff *skb, unsigned char *headers, s64 slot)
1472 struct tile_net_priv *priv = netdev_priv(dev);
1473 struct skb_shared_info *sh = skb_shinfo(skb);
1474 unsigned int data_len = skb->data_len;
1475 unsigned int p_len = sh->gso_size;
1476 gxio_mpipe_edesc_t edesc_head = { { 0 } };
1477 gxio_mpipe_edesc_t edesc_body = { { 0 } };
1478 long f_id = -1; /* id of the current fragment */
1479 long f_size = -1; /* size of the current fragment */
1480 long f_used = -1; /* bytes used from the current fragment */
1481 long n; /* size of the current piece of payload */
1482 unsigned long tx_packets = 0, tx_bytes = 0;
1483 unsigned int csum_start, sh_len;
1486 /* Prepare to egress the headers: set up header edesc. */
1487 csum_start = skb_checksum_start_offset(skb);
1488 sh_len = skb_transport_offset(skb) + tcp_hdrlen(skb);
1489 edesc_head.csum = 1;
1490 edesc_head.csum_start = csum_start;
1491 edesc_head.csum_dest = csum_start + skb->csum_offset;
1492 edesc_head.xfer_size = sh_len;
1494 /* This is only used to specify the TLB. */
1495 edesc_head.stack_idx = large_buffer_stack;
1496 edesc_body.stack_idx = large_buffer_stack;
1498 /* Egress all the edescs. */
1499 for (segment = 0; segment < sh->gso_segs; segment++) {
1502 unsigned int p_used = 0;
1504 /* Egress the header. */
1505 buf = headers + (slot % EQUEUE_ENTRIES) * HEADER_BYTES +
1507 edesc_head.va = va_to_tile_io_addr(buf);
1508 gxio_mpipe_equeue_put_at(equeue, edesc_head, slot);
1511 /* Egress the payload. */
1512 while (p_used < p_len) {
1514 /* Advance as needed. */
1515 while (f_used >= f_size) {
1517 f_size = sh->frags[f_id].size;
1521 va = tile_net_frag_buf(&sh->frags[f_id]) + f_used;
1523 /* Use bytes from the current fragment. */
1525 if (n > f_size - f_used)
1526 n = f_size - f_used;
1530 /* Egress a piece of the payload. */
1531 edesc_body.va = va_to_tile_io_addr(va);
1532 edesc_body.xfer_size = n;
1533 edesc_body.bound = !(p_used < p_len);
1534 gxio_mpipe_equeue_put_at(equeue, edesc_body, slot);
1539 tx_bytes += sh_len + p_len;
1541 /* The last segment may be less than gso_size. */
1543 if (data_len < p_len)
1548 tile_net_stats_add(tx_packets, &priv->stats.tx_packets);
1549 tile_net_stats_add(tx_bytes, &priv->stats.tx_bytes);
1552 /* Do "TSO" handling for egress.
1554 * Normally drivers set NETIF_F_TSO only to support hardware TSO;
1555 * otherwise the stack uses scatter-gather to implement GSO in software.
1556 * On our testing, enabling GSO support (via NETIF_F_SG) drops network
1557 * performance down to around 7.5 Gbps on the 10G interfaces, although
1558 * also dropping cpu utilization way down, to under 8%. But
1559 * implementing "TSO" in the driver brings performance back up to line
1560 * rate, while dropping cpu usage even further, to less than 4%. In
1561 * practice, profiling of GSO shows that skb_segment() is what causes
1562 * the performance overheads; we benefit in the driver from using
1563 * preallocated memory to duplicate the TCP/IP headers.
1565 static int tile_net_tx_tso(struct sk_buff *skb, struct net_device *dev)
1567 struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
1568 struct tile_net_priv *priv = netdev_priv(dev);
1569 int channel = priv->echannel;
1570 struct tile_net_egress *egress = &egress_for_echannel[channel];
1571 struct tile_net_comps *comps = info->comps_for_echannel[channel];
1572 gxio_mpipe_equeue_t *equeue = egress->equeue;
1573 unsigned long irqflags;
1577 /* Determine how many mpipe edesc's are needed. */
1578 num_edescs = tso_count_edescs(skb);
1580 local_irq_save(irqflags);
1582 /* Try to acquire a completion entry and an egress slot. */
1583 slot = tile_net_equeue_try_reserve(dev, comps, equeue, num_edescs);
1585 local_irq_restore(irqflags);
1586 return NETDEV_TX_BUSY;
1589 /* Set up copies of header data properly. */
1590 tso_headers_prepare(skb, egress->headers, slot);
1592 /* Actually pass the data to the network hardware. */
1593 tso_egress(dev, equeue, skb, egress->headers, slot);
1595 /* Add a completion record. */
1596 add_comp(equeue, comps, slot + num_edescs - 1, skb);
1598 local_irq_restore(irqflags);
1600 /* Make sure the egress timer is scheduled. */
1601 tile_net_schedule_egress_timer();
1603 return NETDEV_TX_OK;
1606 /* Analyze the body and frags for a transmit request. */
1607 static unsigned int tile_net_tx_frags(struct frag *frags,
1608 struct sk_buff *skb,
1609 void *b_data, unsigned int b_len)
1611 unsigned int i, n = 0;
1613 struct skb_shared_info *sh = skb_shinfo(skb);
1616 frags[n].buf = b_data;
1617 frags[n++].length = b_len;
1620 for (i = 0; i < sh->nr_frags; i++) {
1621 skb_frag_t *f = &sh->frags[i];
1622 frags[n].buf = tile_net_frag_buf(f);
1623 frags[n++].length = skb_frag_size(f);
1629 /* Help the kernel transmit a packet. */
1630 static int tile_net_tx(struct sk_buff *skb, struct net_device *dev)
1632 struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
1633 struct tile_net_priv *priv = netdev_priv(dev);
1634 struct tile_net_egress *egress = &egress_for_echannel[priv->echannel];
1635 gxio_mpipe_equeue_t *equeue = egress->equeue;
1636 struct tile_net_comps *comps =
1637 info->comps_for_echannel[priv->echannel];
1638 unsigned int len = skb->len;
1639 unsigned char *data = skb->data;
1640 unsigned int num_edescs;
1641 struct frag frags[MAX_FRAGS];
1642 gxio_mpipe_edesc_t edescs[MAX_FRAGS];
1643 unsigned long irqflags;
1644 gxio_mpipe_edesc_t edesc = { { 0 } };
1648 if (skb_is_gso(skb))
1649 return tile_net_tx_tso(skb, dev);
1651 num_edescs = tile_net_tx_frags(frags, skb, data, skb_headlen(skb));
1653 /* This is only used to specify the TLB. */
1654 edesc.stack_idx = large_buffer_stack;
1656 /* Prepare the edescs. */
1657 for (i = 0; i < num_edescs; i++) {
1658 edesc.xfer_size = frags[i].length;
1659 edesc.va = va_to_tile_io_addr(frags[i].buf);
1663 /* Mark the final edesc. */
1664 edescs[num_edescs - 1].bound = 1;
1666 /* Add checksum info to the initial edesc, if needed. */
1667 if (skb->ip_summed == CHECKSUM_PARTIAL) {
1668 unsigned int csum_start = skb_checksum_start_offset(skb);
1670 edescs[0].csum_start = csum_start;
1671 edescs[0].csum_dest = csum_start + skb->csum_offset;
1674 local_irq_save(irqflags);
1676 /* Try to acquire a completion entry and an egress slot. */
1677 slot = tile_net_equeue_try_reserve(dev, comps, equeue, num_edescs);
1679 local_irq_restore(irqflags);
1680 return NETDEV_TX_BUSY;
1683 for (i = 0; i < num_edescs; i++)
1684 gxio_mpipe_equeue_put_at(equeue, edescs[i], slot++);
1686 /* Add a completion record. */
1687 add_comp(equeue, comps, slot - 1, skb);
1689 /* NOTE: Use ETH_ZLEN for short packets (e.g. 42 < 60). */
1690 tile_net_stats_add(1, &priv->stats.tx_packets);
1691 tile_net_stats_add(max_t(unsigned int, len, ETH_ZLEN),
1692 &priv->stats.tx_bytes);
1694 local_irq_restore(irqflags);
1696 /* Make sure the egress timer is scheduled. */
1697 tile_net_schedule_egress_timer();
1699 return NETDEV_TX_OK;
1702 /* Return subqueue id on this core (one per core). */
1703 static u16 tile_net_select_queue(struct net_device *dev, struct sk_buff *skb)
1705 return smp_processor_id();
1708 /* Deal with a transmit timeout. */
1709 static void tile_net_tx_timeout(struct net_device *dev)
1713 for_each_online_cpu(cpu)
1714 netif_wake_subqueue(dev, cpu);
1717 /* Ioctl commands. */
1718 static int tile_net_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
1723 /* Get system network statistics for device. */
1724 static struct net_device_stats *tile_net_get_stats(struct net_device *dev)
1726 struct tile_net_priv *priv = netdev_priv(dev);
1727 return &priv->stats;
1730 /* Change the MTU. */
1731 static int tile_net_change_mtu(struct net_device *dev, int new_mtu)
1733 if ((new_mtu < 68) || (new_mtu > 1500))
1739 /* Change the Ethernet address of the NIC.
1741 * The hypervisor driver does not support changing MAC address. However,
1742 * the hardware does not do anything with the MAC address, so the address
1743 * which gets used on outgoing packets, and which is accepted on incoming
1744 * packets, is completely up to us.
1746 * Returns 0 on success, negative on failure.
1748 static int tile_net_set_mac_address(struct net_device *dev, void *p)
1750 struct sockaddr *addr = p;
1752 if (!is_valid_ether_addr(addr->sa_data))
1754 memcpy(dev->dev_addr, addr->sa_data, dev->addr_len);
1758 #ifdef CONFIG_NET_POLL_CONTROLLER
1759 /* Polling 'interrupt' - used by things like netconsole to send skbs
1760 * without having to re-enable interrupts. It's not called while
1761 * the interrupt routine is executing.
1763 static void tile_net_netpoll(struct net_device *dev)
1765 disable_percpu_irq(ingress_irq);
1766 tile_net_handle_ingress_irq(ingress_irq, NULL);
1767 enable_percpu_irq(ingress_irq, 0);
1771 static const struct net_device_ops tile_net_ops = {
1772 .ndo_open = tile_net_open,
1773 .ndo_stop = tile_net_stop,
1774 .ndo_start_xmit = tile_net_tx,
1775 .ndo_select_queue = tile_net_select_queue,
1776 .ndo_do_ioctl = tile_net_ioctl,
1777 .ndo_get_stats = tile_net_get_stats,
1778 .ndo_change_mtu = tile_net_change_mtu,
1779 .ndo_tx_timeout = tile_net_tx_timeout,
1780 .ndo_set_mac_address = tile_net_set_mac_address,
1781 #ifdef CONFIG_NET_POLL_CONTROLLER
1782 .ndo_poll_controller = tile_net_netpoll,
1786 /* The setup function.
1788 * This uses ether_setup() to assign various fields in dev, including
1789 * setting IFF_BROADCAST and IFF_MULTICAST, then sets some extra fields.
1791 static void tile_net_setup(struct net_device *dev)
1794 dev->netdev_ops = &tile_net_ops;
1795 dev->watchdog_timeo = TILE_NET_TIMEOUT;
1796 dev->features |= NETIF_F_LLTX;
1797 dev->features |= NETIF_F_HW_CSUM;
1798 dev->features |= NETIF_F_SG;
1799 dev->features |= NETIF_F_TSO;
1803 /* Allocate the device structure, register the device, and obtain the
1804 * MAC address from the hypervisor.
1806 static void tile_net_dev_init(const char *name, const uint8_t *mac)
1811 struct net_device *dev;
1812 struct tile_net_priv *priv;
1814 /* HACK: Ignore "loop" links. */
1815 if (strncmp(name, "loop", 4) == 0)
1818 /* Allocate the device structure. Normally, "name" is a
1819 * template, instantiated by register_netdev(), but not for us.
1821 dev = alloc_netdev_mqs(sizeof(*priv), name, tile_net_setup,
1824 pr_err("alloc_netdev_mqs(%s) failed\n", name);
1828 /* Initialize "priv". */
1829 priv = netdev_priv(dev);
1830 memset(priv, 0, sizeof(*priv));
1833 priv->loopify_channel = -1;
1834 priv->echannel = -1;
1836 /* Get the MAC address and set it in the device struct; this must
1837 * be done before the device is opened. If the MAC is all zeroes,
1838 * we use a random address, since we're probably on the simulator.
1840 for (i = 0; i < 6; i++)
1844 memcpy(dev->dev_addr, mac, 6);
1847 random_ether_addr(dev->dev_addr);
1850 /* Register the network device. */
1851 ret = register_netdev(dev);
1853 netdev_err(dev, "register_netdev failed %d\n", ret);
1859 /* Per-cpu module initialization. */
1860 static void tile_net_init_module_percpu(void *unused)
1862 struct tile_net_info *info = &__get_cpu_var(per_cpu_info);
1863 int my_cpu = smp_processor_id();
1865 info->has_iqueue = false;
1867 info->my_cpu = my_cpu;
1869 /* Initialize the egress timer. */
1870 hrtimer_init(&info->egress_timer, CLOCK_MONOTONIC, HRTIMER_MODE_REL);
1871 info->egress_timer.function = tile_net_handle_egress_timer;
1874 /* Module initialization. */
1875 static int __init tile_net_init_module(void)
1878 char name[GXIO_MPIPE_LINK_NAME_LEN];
1881 pr_info("Tilera Network Driver\n");
1883 mutex_init(&tile_net_devs_for_channel_mutex);
1885 /* Initialize each CPU. */
1886 on_each_cpu(tile_net_init_module_percpu, NULL, 1);
1888 /* Find out what devices we have, and initialize them. */
1889 for (i = 0; gxio_mpipe_link_enumerate_mac(i, name, mac) >= 0; i++)
1890 tile_net_dev_init(name, mac);
1892 if (!network_cpus_init())
1893 network_cpus_map = *cpu_online_mask;
1898 module_init(tile_net_init_module);