linux/drivers/net/ethernet/tile/tilegx.c

1906 lines
53 KiB
C

/*
* 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, NULL, 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),
1, 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->data_len + skb->hdr_len - sh_len;
unsigned int p_len = sh->gso_size;
long f_id = -1; /* id of the current fragment */
long f_size = skb->hdr_len; /* size of the current fragment */
long f_used = sh_len; /* 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 = sh->frags[f_id].size;
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->data_len + skb->hdr_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->hdr_len; /* size of the current fragment */
long f_used = sh_len; /* 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(sh_len + data_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 = sh->frags[f_id].size;
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->data_len + skb->hdr_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->hdr_len; /* size of the current fragment */
long f_used = sh_len; /* bytes used from the current fragment */
void *f_data = skb->data;
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) {
/* Advance as needed. */
while (f_used >= f_size) {
f_id++;
f_size = sh->frags[f_id].size;
f_used = 0;
f_data = tile_net_frag_buf(&sh->frags[f_id]);
}
/* 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(f_data) + f_used;
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);