linux/net/sched/sch_taprio.c

1230 lines
29 KiB
C

// SPDX-License-Identifier: GPL-2.0
/* net/sched/sch_taprio.c Time Aware Priority Scheduler
*
* Authors: Vinicius Costa Gomes <vinicius.gomes@intel.com>
*
*/
#include <linux/types.h>
#include <linux/slab.h>
#include <linux/kernel.h>
#include <linux/string.h>
#include <linux/list.h>
#include <linux/errno.h>
#include <linux/skbuff.h>
#include <linux/math64.h>
#include <linux/module.h>
#include <linux/spinlock.h>
#include <linux/rcupdate.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
#include <net/sch_generic.h>
static LIST_HEAD(taprio_list);
static DEFINE_SPINLOCK(taprio_list_lock);
#define TAPRIO_ALL_GATES_OPEN -1
struct sched_entry {
struct list_head list;
/* The instant that this entry "closes" and the next one
* should open, the qdisc will make some effort so that no
* packet leaves after this time.
*/
ktime_t close_time;
atomic_t budget;
int index;
u32 gate_mask;
u32 interval;
u8 command;
};
struct sched_gate_list {
struct rcu_head rcu;
struct list_head entries;
size_t num_entries;
ktime_t cycle_close_time;
s64 cycle_time;
s64 cycle_time_extension;
s64 base_time;
};
struct taprio_sched {
struct Qdisc **qdiscs;
struct Qdisc *root;
int clockid;
atomic64_t picos_per_byte; /* Using picoseconds because for 10Gbps+
* speeds it's sub-nanoseconds per byte
*/
/* Protects the update side of the RCU protected current_entry */
spinlock_t current_entry_lock;
struct sched_entry __rcu *current_entry;
struct sched_gate_list __rcu *oper_sched;
struct sched_gate_list __rcu *admin_sched;
ktime_t (*get_time)(void);
struct hrtimer advance_timer;
struct list_head taprio_list;
};
static ktime_t sched_base_time(const struct sched_gate_list *sched)
{
if (!sched)
return KTIME_MAX;
return ns_to_ktime(sched->base_time);
}
static void taprio_free_sched_cb(struct rcu_head *head)
{
struct sched_gate_list *sched = container_of(head, struct sched_gate_list, rcu);
struct sched_entry *entry, *n;
if (!sched)
return;
list_for_each_entry_safe(entry, n, &sched->entries, list) {
list_del(&entry->list);
kfree(entry);
}
kfree(sched);
}
static void switch_schedules(struct taprio_sched *q,
struct sched_gate_list **admin,
struct sched_gate_list **oper)
{
rcu_assign_pointer(q->oper_sched, *admin);
rcu_assign_pointer(q->admin_sched, NULL);
if (*oper)
call_rcu(&(*oper)->rcu, taprio_free_sched_cb);
*oper = *admin;
*admin = NULL;
}
static ktime_t get_cycle_time(struct sched_gate_list *sched)
{
struct sched_entry *entry;
ktime_t cycle = 0;
if (sched->cycle_time != 0)
return sched->cycle_time;
list_for_each_entry(entry, &sched->entries, list)
cycle = ktime_add_ns(cycle, entry->interval);
sched->cycle_time = cycle;
return cycle;
}
static int taprio_enqueue(struct sk_buff *skb, struct Qdisc *sch,
struct sk_buff **to_free)
{
struct taprio_sched *q = qdisc_priv(sch);
struct Qdisc *child;
int queue;
queue = skb_get_queue_mapping(skb);
child = q->qdiscs[queue];
if (unlikely(!child))
return qdisc_drop(skb, sch, to_free);
qdisc_qstats_backlog_inc(sch, skb);
sch->q.qlen++;
return qdisc_enqueue(skb, child, to_free);
}
static struct sk_buff *taprio_peek(struct Qdisc *sch)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
struct sched_entry *entry;
struct sk_buff *skb;
u32 gate_mask;
int i;
rcu_read_lock();
entry = rcu_dereference(q->current_entry);
gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;
rcu_read_unlock();
if (!gate_mask)
return NULL;
for (i = 0; i < dev->num_tx_queues; i++) {
struct Qdisc *child = q->qdiscs[i];
int prio;
u8 tc;
if (unlikely(!child))
continue;
skb = child->ops->peek(child);
if (!skb)
continue;
prio = skb->priority;
tc = netdev_get_prio_tc_map(dev, prio);
if (!(gate_mask & BIT(tc)))
continue;
return skb;
}
return NULL;
}
static inline int length_to_duration(struct taprio_sched *q, int len)
{
return div_u64(len * atomic64_read(&q->picos_per_byte), 1000);
}
static void taprio_set_budget(struct taprio_sched *q, struct sched_entry *entry)
{
atomic_set(&entry->budget,
div64_u64((u64)entry->interval * 1000,
atomic64_read(&q->picos_per_byte)));
}
static struct sk_buff *taprio_dequeue(struct Qdisc *sch)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
struct sk_buff *skb = NULL;
struct sched_entry *entry;
u32 gate_mask;
int i;
if (atomic64_read(&q->picos_per_byte) == -1) {
WARN_ONCE(1, "taprio: dequeue() called with unknown picos per byte.");
return NULL;
}
rcu_read_lock();
entry = rcu_dereference(q->current_entry);
/* if there's no entry, it means that the schedule didn't
* start yet, so force all gates to be open, this is in
* accordance to IEEE 802.1Qbv-2015 Section 8.6.9.4.5
* "AdminGateSates"
*/
gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;
if (!gate_mask)
goto done;
for (i = 0; i < dev->num_tx_queues; i++) {
struct Qdisc *child = q->qdiscs[i];
ktime_t guard;
int prio;
int len;
u8 tc;
if (unlikely(!child))
continue;
skb = child->ops->peek(child);
if (!skb)
continue;
prio = skb->priority;
tc = netdev_get_prio_tc_map(dev, prio);
if (!(gate_mask & BIT(tc)))
continue;
len = qdisc_pkt_len(skb);
guard = ktime_add_ns(q->get_time(),
length_to_duration(q, len));
/* In the case that there's no gate entry, there's no
* guard band ...
*/
if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
ktime_after(guard, entry->close_time))
continue;
/* ... and no budget. */
if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
atomic_sub_return(len, &entry->budget) < 0)
continue;
skb = child->ops->dequeue(child);
if (unlikely(!skb))
goto done;
qdisc_bstats_update(sch, skb);
qdisc_qstats_backlog_dec(sch, skb);
sch->q.qlen--;
goto done;
}
done:
rcu_read_unlock();
return skb;
}
static bool should_restart_cycle(const struct sched_gate_list *oper,
const struct sched_entry *entry)
{
if (list_is_last(&entry->list, &oper->entries))
return true;
if (ktime_compare(entry->close_time, oper->cycle_close_time) == 0)
return true;
return false;
}
static bool should_change_schedules(const struct sched_gate_list *admin,
const struct sched_gate_list *oper,
ktime_t close_time)
{
ktime_t next_base_time, extension_time;
if (!admin)
return false;
next_base_time = sched_base_time(admin);
/* This is the simple case, the close_time would fall after
* the next schedule base_time.
*/
if (ktime_compare(next_base_time, close_time) <= 0)
return true;
/* This is the cycle_time_extension case, if the close_time
* plus the amount that can be extended would fall after the
* next schedule base_time, we can extend the current schedule
* for that amount.
*/
extension_time = ktime_add_ns(close_time, oper->cycle_time_extension);
/* FIXME: the IEEE 802.1Q-2018 Specification isn't clear about
* how precisely the extension should be made. So after
* conformance testing, this logic may change.
*/
if (ktime_compare(next_base_time, extension_time) <= 0)
return true;
return false;
}
static enum hrtimer_restart advance_sched(struct hrtimer *timer)
{
struct taprio_sched *q = container_of(timer, struct taprio_sched,
advance_timer);
struct sched_gate_list *oper, *admin;
struct sched_entry *entry, *next;
struct Qdisc *sch = q->root;
ktime_t close_time;
spin_lock(&q->current_entry_lock);
entry = rcu_dereference_protected(q->current_entry,
lockdep_is_held(&q->current_entry_lock));
oper = rcu_dereference_protected(q->oper_sched,
lockdep_is_held(&q->current_entry_lock));
admin = rcu_dereference_protected(q->admin_sched,
lockdep_is_held(&q->current_entry_lock));
if (!oper)
switch_schedules(q, &admin, &oper);
/* This can happen in two cases: 1. this is the very first run
* of this function (i.e. we weren't running any schedule
* previously); 2. The previous schedule just ended. The first
* entry of all schedules are pre-calculated during the
* schedule initialization.
*/
if (unlikely(!entry || entry->close_time == oper->base_time)) {
next = list_first_entry(&oper->entries, struct sched_entry,
list);
close_time = next->close_time;
goto first_run;
}
if (should_restart_cycle(oper, entry)) {
next = list_first_entry(&oper->entries, struct sched_entry,
list);
oper->cycle_close_time = ktime_add_ns(oper->cycle_close_time,
oper->cycle_time);
} else {
next = list_next_entry(entry, list);
}
close_time = ktime_add_ns(entry->close_time, next->interval);
close_time = min_t(ktime_t, close_time, oper->cycle_close_time);
if (should_change_schedules(admin, oper, close_time)) {
/* Set things so the next time this runs, the new
* schedule runs.
*/
close_time = sched_base_time(admin);
switch_schedules(q, &admin, &oper);
}
next->close_time = close_time;
taprio_set_budget(q, next);
first_run:
rcu_assign_pointer(q->current_entry, next);
spin_unlock(&q->current_entry_lock);
hrtimer_set_expires(&q->advance_timer, close_time);
rcu_read_lock();
__netif_schedule(sch);
rcu_read_unlock();
return HRTIMER_RESTART;
}
static const struct nla_policy entry_policy[TCA_TAPRIO_SCHED_ENTRY_MAX + 1] = {
[TCA_TAPRIO_SCHED_ENTRY_INDEX] = { .type = NLA_U32 },
[TCA_TAPRIO_SCHED_ENTRY_CMD] = { .type = NLA_U8 },
[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK] = { .type = NLA_U32 },
[TCA_TAPRIO_SCHED_ENTRY_INTERVAL] = { .type = NLA_U32 },
};
static const struct nla_policy entry_list_policy[TCA_TAPRIO_SCHED_MAX + 1] = {
[TCA_TAPRIO_SCHED_ENTRY] = { .type = NLA_NESTED },
};
static const struct nla_policy taprio_policy[TCA_TAPRIO_ATTR_MAX + 1] = {
[TCA_TAPRIO_ATTR_PRIOMAP] = {
.len = sizeof(struct tc_mqprio_qopt)
},
[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST] = { .type = NLA_NESTED },
[TCA_TAPRIO_ATTR_SCHED_BASE_TIME] = { .type = NLA_S64 },
[TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY] = { .type = NLA_NESTED },
[TCA_TAPRIO_ATTR_SCHED_CLOCKID] = { .type = NLA_S32 },
[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME] = { .type = NLA_S64 },
[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION] = { .type = NLA_S64 },
};
static int fill_sched_entry(struct nlattr **tb, struct sched_entry *entry,
struct netlink_ext_ack *extack)
{
u32 interval = 0;
if (tb[TCA_TAPRIO_SCHED_ENTRY_CMD])
entry->command = nla_get_u8(
tb[TCA_TAPRIO_SCHED_ENTRY_CMD]);
if (tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK])
entry->gate_mask = nla_get_u32(
tb[TCA_TAPRIO_SCHED_ENTRY_GATE_MASK]);
if (tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL])
interval = nla_get_u32(
tb[TCA_TAPRIO_SCHED_ENTRY_INTERVAL]);
if (interval == 0) {
NL_SET_ERR_MSG(extack, "Invalid interval for schedule entry");
return -EINVAL;
}
entry->interval = interval;
return 0;
}
static int parse_sched_entry(struct nlattr *n, struct sched_entry *entry,
int index, struct netlink_ext_ack *extack)
{
struct nlattr *tb[TCA_TAPRIO_SCHED_ENTRY_MAX + 1] = { };
int err;
err = nla_parse_nested_deprecated(tb, TCA_TAPRIO_SCHED_ENTRY_MAX, n,
entry_policy, NULL);
if (err < 0) {
NL_SET_ERR_MSG(extack, "Could not parse nested entry");
return -EINVAL;
}
entry->index = index;
return fill_sched_entry(tb, entry, extack);
}
static int parse_sched_list(struct nlattr *list,
struct sched_gate_list *sched,
struct netlink_ext_ack *extack)
{
struct nlattr *n;
int err, rem;
int i = 0;
if (!list)
return -EINVAL;
nla_for_each_nested(n, list, rem) {
struct sched_entry *entry;
if (nla_type(n) != TCA_TAPRIO_SCHED_ENTRY) {
NL_SET_ERR_MSG(extack, "Attribute is not of type 'entry'");
continue;
}
entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (!entry) {
NL_SET_ERR_MSG(extack, "Not enough memory for entry");
return -ENOMEM;
}
err = parse_sched_entry(n, entry, i, extack);
if (err < 0) {
kfree(entry);
return err;
}
list_add_tail(&entry->list, &sched->entries);
i++;
}
sched->num_entries = i;
return i;
}
static int parse_taprio_schedule(struct nlattr **tb,
struct sched_gate_list *new,
struct netlink_ext_ack *extack)
{
int err = 0;
if (tb[TCA_TAPRIO_ATTR_SCHED_SINGLE_ENTRY]) {
NL_SET_ERR_MSG(extack, "Adding a single entry is not supported");
return -ENOTSUPP;
}
if (tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME])
new->base_time = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_BASE_TIME]);
if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION])
new->cycle_time_extension = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION]);
if (tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME])
new->cycle_time = nla_get_s64(tb[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME]);
if (tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST])
err = parse_sched_list(
tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST], new, extack);
if (err < 0)
return err;
return 0;
}
static int taprio_parse_mqprio_opt(struct net_device *dev,
struct tc_mqprio_qopt *qopt,
struct netlink_ext_ack *extack)
{
int i, j;
if (!qopt && !dev->num_tc) {
NL_SET_ERR_MSG(extack, "'mqprio' configuration is necessary");
return -EINVAL;
}
/* If num_tc is already set, it means that the user already
* configured the mqprio part
*/
if (dev->num_tc)
return 0;
/* Verify num_tc is not out of max range */
if (qopt->num_tc > TC_MAX_QUEUE) {
NL_SET_ERR_MSG(extack, "Number of traffic classes is outside valid range");
return -EINVAL;
}
/* taprio imposes that traffic classes map 1:n to tx queues */
if (qopt->num_tc > dev->num_tx_queues) {
NL_SET_ERR_MSG(extack, "Number of traffic classes is greater than number of HW queues");
return -EINVAL;
}
/* Verify priority mapping uses valid tcs */
for (i = 0; i < TC_BITMASK + 1; i++) {
if (qopt->prio_tc_map[i] >= qopt->num_tc) {
NL_SET_ERR_MSG(extack, "Invalid traffic class in priority to traffic class mapping");
return -EINVAL;
}
}
for (i = 0; i < qopt->num_tc; i++) {
unsigned int last = qopt->offset[i] + qopt->count[i];
/* Verify the queue count is in tx range being equal to the
* real_num_tx_queues indicates the last queue is in use.
*/
if (qopt->offset[i] >= dev->num_tx_queues ||
!qopt->count[i] ||
last > dev->real_num_tx_queues) {
NL_SET_ERR_MSG(extack, "Invalid queue in traffic class to queue mapping");
return -EINVAL;
}
/* Verify that the offset and counts do not overlap */
for (j = i + 1; j < qopt->num_tc; j++) {
if (last > qopt->offset[j]) {
NL_SET_ERR_MSG(extack, "Detected overlap in the traffic class to queue mapping");
return -EINVAL;
}
}
}
return 0;
}
static int taprio_get_start_time(struct Qdisc *sch,
struct sched_gate_list *sched,
ktime_t *start)
{
struct taprio_sched *q = qdisc_priv(sch);
ktime_t now, base, cycle;
s64 n;
base = sched_base_time(sched);
now = q->get_time();
if (ktime_after(base, now)) {
*start = base;
return 0;
}
cycle = get_cycle_time(sched);
/* The qdisc is expected to have at least one sched_entry. Moreover,
* any entry must have 'interval' > 0. Thus if the cycle time is zero,
* something went really wrong. In that case, we should warn about this
* inconsistent state and return error.
*/
if (WARN_ON(!cycle))
return -EFAULT;
/* Schedule the start time for the beginning of the next
* cycle.
*/
n = div64_s64(ktime_sub_ns(now, base), cycle);
*start = ktime_add_ns(base, (n + 1) * cycle);
return 0;
}
static void setup_first_close_time(struct taprio_sched *q,
struct sched_gate_list *sched, ktime_t base)
{
struct sched_entry *first;
ktime_t cycle;
first = list_first_entry(&sched->entries,
struct sched_entry, list);
cycle = get_cycle_time(sched);
/* FIXME: find a better place to do this */
sched->cycle_close_time = ktime_add_ns(base, cycle);
first->close_time = ktime_add_ns(base, first->interval);
taprio_set_budget(q, first);
rcu_assign_pointer(q->current_entry, NULL);
}
static void taprio_start_sched(struct Qdisc *sch,
ktime_t start, struct sched_gate_list *new)
{
struct taprio_sched *q = qdisc_priv(sch);
ktime_t expires;
expires = hrtimer_get_expires(&q->advance_timer);
if (expires == 0)
expires = KTIME_MAX;
/* If the new schedule starts before the next expiration, we
* reprogram it to the earliest one, so we change the admin
* schedule to the operational one at the right time.
*/
start = min_t(ktime_t, start, expires);
hrtimer_start(&q->advance_timer, start, HRTIMER_MODE_ABS);
}
static void taprio_set_picos_per_byte(struct net_device *dev,
struct taprio_sched *q)
{
struct ethtool_link_ksettings ecmd;
int picos_per_byte = -1;
if (!__ethtool_get_link_ksettings(dev, &ecmd) &&
ecmd.base.speed != SPEED_UNKNOWN)
picos_per_byte = div64_s64(NSEC_PER_SEC * 1000LL * 8,
ecmd.base.speed * 1000 * 1000);
atomic64_set(&q->picos_per_byte, picos_per_byte);
netdev_dbg(dev, "taprio: set %s's picos_per_byte to: %lld, linkspeed: %d\n",
dev->name, (long long)atomic64_read(&q->picos_per_byte),
ecmd.base.speed);
}
static int taprio_dev_notifier(struct notifier_block *nb, unsigned long event,
void *ptr)
{
struct net_device *dev = netdev_notifier_info_to_dev(ptr);
struct net_device *qdev;
struct taprio_sched *q;
bool found = false;
ASSERT_RTNL();
if (event != NETDEV_UP && event != NETDEV_CHANGE)
return NOTIFY_DONE;
spin_lock(&taprio_list_lock);
list_for_each_entry(q, &taprio_list, taprio_list) {
qdev = qdisc_dev(q->root);
if (qdev == dev) {
found = true;
break;
}
}
spin_unlock(&taprio_list_lock);
if (found)
taprio_set_picos_per_byte(dev, q);
return NOTIFY_DONE;
}
static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[TCA_TAPRIO_ATTR_MAX + 1] = { };
struct sched_gate_list *oper, *admin, *new_admin;
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
struct tc_mqprio_qopt *mqprio = NULL;
int i, err, clockid;
unsigned long flags;
ktime_t start;
err = nla_parse_nested_deprecated(tb, TCA_TAPRIO_ATTR_MAX, opt,
taprio_policy, extack);
if (err < 0)
return err;
if (tb[TCA_TAPRIO_ATTR_PRIOMAP])
mqprio = nla_data(tb[TCA_TAPRIO_ATTR_PRIOMAP]);
err = taprio_parse_mqprio_opt(dev, mqprio, extack);
if (err < 0)
return err;
new_admin = kzalloc(sizeof(*new_admin), GFP_KERNEL);
if (!new_admin) {
NL_SET_ERR_MSG(extack, "Not enough memory for a new schedule");
return -ENOMEM;
}
INIT_LIST_HEAD(&new_admin->entries);
rcu_read_lock();
oper = rcu_dereference(q->oper_sched);
admin = rcu_dereference(q->admin_sched);
rcu_read_unlock();
if (mqprio && (oper || admin)) {
NL_SET_ERR_MSG(extack, "Changing the traffic mapping of a running schedule is not supported");
err = -ENOTSUPP;
goto free_sched;
}
err = parse_taprio_schedule(tb, new_admin, extack);
if (err < 0)
goto free_sched;
if (new_admin->num_entries == 0) {
NL_SET_ERR_MSG(extack, "There should be at least one entry in the schedule");
err = -EINVAL;
goto free_sched;
}
if (tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]) {
clockid = nla_get_s32(tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]);
/* We only support static clockids and we don't allow
* for it to be modified after the first init.
*/
if (clockid < 0 ||
(q->clockid != -1 && q->clockid != clockid)) {
NL_SET_ERR_MSG(extack, "Changing the 'clockid' of a running schedule is not supported");
err = -ENOTSUPP;
goto free_sched;
}
q->clockid = clockid;
}
if (q->clockid == -1 && !tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]) {
NL_SET_ERR_MSG(extack, "Specifying a 'clockid' is mandatory");
err = -EINVAL;
goto free_sched;
}
taprio_set_picos_per_byte(dev, q);
/* Protects against enqueue()/dequeue() */
spin_lock_bh(qdisc_lock(sch));
if (!hrtimer_active(&q->advance_timer)) {
hrtimer_init(&q->advance_timer, q->clockid, HRTIMER_MODE_ABS);
q->advance_timer.function = advance_sched;
}
if (mqprio) {
netdev_set_num_tc(dev, mqprio->num_tc);
for (i = 0; i < mqprio->num_tc; i++)
netdev_set_tc_queue(dev, i,
mqprio->count[i],
mqprio->offset[i]);
/* Always use supplied priority mappings */
for (i = 0; i < TC_BITMASK + 1; i++)
netdev_set_prio_tc_map(dev, i,
mqprio->prio_tc_map[i]);
}
switch (q->clockid) {
case CLOCK_REALTIME:
q->get_time = ktime_get_real;
break;
case CLOCK_MONOTONIC:
q->get_time = ktime_get;
break;
case CLOCK_BOOTTIME:
q->get_time = ktime_get_boottime;
break;
case CLOCK_TAI:
q->get_time = ktime_get_clocktai;
break;
default:
NL_SET_ERR_MSG(extack, "Invalid 'clockid'");
err = -EINVAL;
goto unlock;
}
err = taprio_get_start_time(sch, new_admin, &start);
if (err < 0) {
NL_SET_ERR_MSG(extack, "Internal error: failed get start time");
goto unlock;
}
setup_first_close_time(q, new_admin, start);
/* Protects against advance_sched() */
spin_lock_irqsave(&q->current_entry_lock, flags);
taprio_start_sched(sch, start, new_admin);
rcu_assign_pointer(q->admin_sched, new_admin);
if (admin)
call_rcu(&admin->rcu, taprio_free_sched_cb);
new_admin = NULL;
spin_unlock_irqrestore(&q->current_entry_lock, flags);
err = 0;
unlock:
spin_unlock_bh(qdisc_lock(sch));
free_sched:
kfree(new_admin);
return err;
}
static void taprio_destroy(struct Qdisc *sch)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
unsigned int i;
spin_lock(&taprio_list_lock);
list_del(&q->taprio_list);
spin_unlock(&taprio_list_lock);
hrtimer_cancel(&q->advance_timer);
if (q->qdiscs) {
for (i = 0; i < dev->num_tx_queues && q->qdiscs[i]; i++)
qdisc_put(q->qdiscs[i]);
kfree(q->qdiscs);
}
q->qdiscs = NULL;
netdev_set_num_tc(dev, 0);
if (q->oper_sched)
call_rcu(&q->oper_sched->rcu, taprio_free_sched_cb);
if (q->admin_sched)
call_rcu(&q->admin_sched->rcu, taprio_free_sched_cb);
}
static int taprio_init(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
int i;
spin_lock_init(&q->current_entry_lock);
hrtimer_init(&q->advance_timer, CLOCK_TAI, HRTIMER_MODE_ABS);
q->advance_timer.function = advance_sched;
q->root = sch;
/* We only support static clockids. Use an invalid value as default
* and get the valid one on taprio_change().
*/
q->clockid = -1;
if (sch->parent != TC_H_ROOT)
return -EOPNOTSUPP;
if (!netif_is_multiqueue(dev))
return -EOPNOTSUPP;
/* pre-allocate qdisc, attachment can't fail */
q->qdiscs = kcalloc(dev->num_tx_queues,
sizeof(q->qdiscs[0]),
GFP_KERNEL);
if (!q->qdiscs)
return -ENOMEM;
if (!opt)
return -EINVAL;
spin_lock(&taprio_list_lock);
list_add(&q->taprio_list, &taprio_list);
spin_unlock(&taprio_list_lock);
for (i = 0; i < dev->num_tx_queues; i++) {
struct netdev_queue *dev_queue;
struct Qdisc *qdisc;
dev_queue = netdev_get_tx_queue(dev, i);
qdisc = qdisc_create_dflt(dev_queue,
&pfifo_qdisc_ops,
TC_H_MAKE(TC_H_MAJ(sch->handle),
TC_H_MIN(i + 1)),
extack);
if (!qdisc)
return -ENOMEM;
if (i < dev->real_num_tx_queues)
qdisc_hash_add(qdisc, false);
q->qdiscs[i] = qdisc;
}
return taprio_change(sch, opt, extack);
}
static struct netdev_queue *taprio_queue_get(struct Qdisc *sch,
unsigned long cl)
{
struct net_device *dev = qdisc_dev(sch);
unsigned long ntx = cl - 1;
if (ntx >= dev->num_tx_queues)
return NULL;
return netdev_get_tx_queue(dev, ntx);
}
static int taprio_graft(struct Qdisc *sch, unsigned long cl,
struct Qdisc *new, struct Qdisc **old,
struct netlink_ext_ack *extack)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
if (!dev_queue)
return -EINVAL;
if (dev->flags & IFF_UP)
dev_deactivate(dev);
*old = q->qdiscs[cl - 1];
q->qdiscs[cl - 1] = new;
if (new)
new->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
if (dev->flags & IFF_UP)
dev_activate(dev);
return 0;
}
static int dump_entry(struct sk_buff *msg,
const struct sched_entry *entry)
{
struct nlattr *item;
item = nla_nest_start_noflag(msg, TCA_TAPRIO_SCHED_ENTRY);
if (!item)
return -ENOSPC;
if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_INDEX, entry->index))
goto nla_put_failure;
if (nla_put_u8(msg, TCA_TAPRIO_SCHED_ENTRY_CMD, entry->command))
goto nla_put_failure;
if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_GATE_MASK,
entry->gate_mask))
goto nla_put_failure;
if (nla_put_u32(msg, TCA_TAPRIO_SCHED_ENTRY_INTERVAL,
entry->interval))
goto nla_put_failure;
return nla_nest_end(msg, item);
nla_put_failure:
nla_nest_cancel(msg, item);
return -1;
}
static int dump_schedule(struct sk_buff *msg,
const struct sched_gate_list *root)
{
struct nlattr *entry_list;
struct sched_entry *entry;
if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_BASE_TIME,
root->base_time, TCA_TAPRIO_PAD))
return -1;
if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME,
root->cycle_time, TCA_TAPRIO_PAD))
return -1;
if (nla_put_s64(msg, TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION,
root->cycle_time_extension, TCA_TAPRIO_PAD))
return -1;
entry_list = nla_nest_start_noflag(msg,
TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST);
if (!entry_list)
goto error_nest;
list_for_each_entry(entry, &root->entries, list) {
if (dump_entry(msg, entry) < 0)
goto error_nest;
}
nla_nest_end(msg, entry_list);
return 0;
error_nest:
nla_nest_cancel(msg, entry_list);
return -1;
}
static int taprio_dump(struct Qdisc *sch, struct sk_buff *skb)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
struct sched_gate_list *oper, *admin;
struct tc_mqprio_qopt opt = { 0 };
struct nlattr *nest, *sched_nest;
unsigned int i;
rcu_read_lock();
oper = rcu_dereference(q->oper_sched);
admin = rcu_dereference(q->admin_sched);
opt.num_tc = netdev_get_num_tc(dev);
memcpy(opt.prio_tc_map, dev->prio_tc_map, sizeof(opt.prio_tc_map));
for (i = 0; i < netdev_get_num_tc(dev); i++) {
opt.count[i] = dev->tc_to_txq[i].count;
opt.offset[i] = dev->tc_to_txq[i].offset;
}
nest = nla_nest_start_noflag(skb, TCA_OPTIONS);
if (!nest)
goto start_error;
if (nla_put(skb, TCA_TAPRIO_ATTR_PRIOMAP, sizeof(opt), &opt))
goto options_error;
if (nla_put_s32(skb, TCA_TAPRIO_ATTR_SCHED_CLOCKID, q->clockid))
goto options_error;
if (oper && dump_schedule(skb, oper))
goto options_error;
if (!admin)
goto done;
sched_nest = nla_nest_start_noflag(skb, TCA_TAPRIO_ATTR_ADMIN_SCHED);
if (!sched_nest)
goto options_error;
if (dump_schedule(skb, admin))
goto admin_error;
nla_nest_end(skb, sched_nest);
done:
rcu_read_unlock();
return nla_nest_end(skb, nest);
admin_error:
nla_nest_cancel(skb, sched_nest);
options_error:
nla_nest_cancel(skb, nest);
start_error:
rcu_read_unlock();
return -ENOSPC;
}
static struct Qdisc *taprio_leaf(struct Qdisc *sch, unsigned long cl)
{
struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
if (!dev_queue)
return NULL;
return dev_queue->qdisc_sleeping;
}
static unsigned long taprio_find(struct Qdisc *sch, u32 classid)
{
unsigned int ntx = TC_H_MIN(classid);
if (!taprio_queue_get(sch, ntx))
return 0;
return ntx;
}
static int taprio_dump_class(struct Qdisc *sch, unsigned long cl,
struct sk_buff *skb, struct tcmsg *tcm)
{
struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
tcm->tcm_parent = TC_H_ROOT;
tcm->tcm_handle |= TC_H_MIN(cl);
tcm->tcm_info = dev_queue->qdisc_sleeping->handle;
return 0;
}
static int taprio_dump_class_stats(struct Qdisc *sch, unsigned long cl,
struct gnet_dump *d)
__releases(d->lock)
__acquires(d->lock)
{
struct netdev_queue *dev_queue = taprio_queue_get(sch, cl);
sch = dev_queue->qdisc_sleeping;
if (gnet_stats_copy_basic(&sch->running, d, NULL, &sch->bstats) < 0 ||
qdisc_qstats_copy(d, sch) < 0)
return -1;
return 0;
}
static void taprio_walk(struct Qdisc *sch, struct qdisc_walker *arg)
{
struct net_device *dev = qdisc_dev(sch);
unsigned long ntx;
if (arg->stop)
return;
arg->count = arg->skip;
for (ntx = arg->skip; ntx < dev->num_tx_queues; ntx++) {
if (arg->fn(sch, ntx + 1, arg) < 0) {
arg->stop = 1;
break;
}
arg->count++;
}
}
static struct netdev_queue *taprio_select_queue(struct Qdisc *sch,
struct tcmsg *tcm)
{
return taprio_queue_get(sch, TC_H_MIN(tcm->tcm_parent));
}
static const struct Qdisc_class_ops taprio_class_ops = {
.graft = taprio_graft,
.leaf = taprio_leaf,
.find = taprio_find,
.walk = taprio_walk,
.dump = taprio_dump_class,
.dump_stats = taprio_dump_class_stats,
.select_queue = taprio_select_queue,
};
static struct Qdisc_ops taprio_qdisc_ops __read_mostly = {
.cl_ops = &taprio_class_ops,
.id = "taprio",
.priv_size = sizeof(struct taprio_sched),
.init = taprio_init,
.change = taprio_change,
.destroy = taprio_destroy,
.peek = taprio_peek,
.dequeue = taprio_dequeue,
.enqueue = taprio_enqueue,
.dump = taprio_dump,
.owner = THIS_MODULE,
};
static struct notifier_block taprio_device_notifier = {
.notifier_call = taprio_dev_notifier,
};
static int __init taprio_module_init(void)
{
int err = register_netdevice_notifier(&taprio_device_notifier);
if (err)
return err;
return register_qdisc(&taprio_qdisc_ops);
}
static void __exit taprio_module_exit(void)
{
unregister_qdisc(&taprio_qdisc_ops);
unregister_netdevice_notifier(&taprio_device_notifier);
}
module_init(taprio_module_init);
module_exit(taprio_module_exit);
MODULE_LICENSE("GPL");