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linux/net/sched/sch_taprio.c
Dmitry Antipov d5c4546062 net: sched: consistently use rcu_replace_pointer() in taprio_change() 
According to Vinicius (and carefully looking through the whole
https://syzkaller.appspot.com/bug?extid=b65e0af58423fc8a73aa
once again), txtime branch of 'taprio_change()' is not going to
race against 'advance_sched()'. But using 'rcu_replace_pointer()'
in the former may be a good idea as well.

Suggested-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: Dmitry Antipov <dmantipov@yandex.ru>
Acked-by: Vinicius Costa Gomes <vinicius.gomes@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2024-09-08 11:18:57 +01:00

2556 lines
66 KiB
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// 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/ethtool.h>
#include <linux/ethtool_netlink.h>
#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 <linux/time.h>
#include <net/gso.h>
#include <net/netlink.h>
#include <net/pkt_sched.h>
#include <net/pkt_cls.h>
#include <net/sch_generic.h>
#include <net/sock.h>
#include <net/tcp.h>
#define TAPRIO_STAT_NOT_SET (~0ULL)
#include "sch_mqprio_lib.h"
static LIST_HEAD(taprio_list);
static struct static_key_false taprio_have_broken_mqprio;
static struct static_key_false taprio_have_working_mqprio;
#define TAPRIO_ALL_GATES_OPEN -1
#define TXTIME_ASSIST_IS_ENABLED(flags) ((flags) & TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST)
#define FULL_OFFLOAD_IS_ENABLED(flags) ((flags) & TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD)
#define TAPRIO_SUPPORTED_FLAGS \
(TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST | TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD)
#define TAPRIO_FLAGS_INVALID U32_MAX
struct sched_entry {
/* Durations between this GCL entry and the GCL entry where the
* respective traffic class gate closes
*/
u64 gate_duration[TC_MAX_QUEUE];
atomic_t budget[TC_MAX_QUEUE];
/* The qdisc makes some effort so that no packet leaves
* after this time
*/
ktime_t gate_close_time[TC_MAX_QUEUE];
struct list_head list;
/* Used to calculate when to advance the schedule */
ktime_t end_time;
ktime_t next_txtime;
int index;
u32 gate_mask;
u32 interval;
u8 command;
};
struct sched_gate_list {
/* Longest non-zero contiguous gate durations per traffic class,
* or 0 if a traffic class gate never opens during the schedule.
*/
u64 max_open_gate_duration[TC_MAX_QUEUE];
u32 max_frm_len[TC_MAX_QUEUE]; /* for the fast path */
u32 max_sdu[TC_MAX_QUEUE]; /* for dump */
struct rcu_head rcu;
struct list_head entries;
size_t num_entries;
ktime_t cycle_end_time;
s64 cycle_time;
s64 cycle_time_extension;
s64 base_time;
};
struct taprio_sched {
struct Qdisc **qdiscs;
struct Qdisc *root;
u32 flags;
enum tk_offsets tk_offset;
int clockid;
bool offloaded;
bool detected_mqprio;
bool broken_mqprio;
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;
struct hrtimer advance_timer;
struct list_head taprio_list;
int cur_txq[TC_MAX_QUEUE];
u32 max_sdu[TC_MAX_QUEUE]; /* save info from the user */
u32 fp[TC_QOPT_MAX_QUEUE]; /* only for dump and offloading */
u32 txtime_delay;
};
struct __tc_taprio_qopt_offload {
refcount_t users;
struct tc_taprio_qopt_offload offload;
};
static void taprio_calculate_gate_durations(struct taprio_sched *q,
struct sched_gate_list *sched)
{
struct net_device *dev = qdisc_dev(q->root);
int num_tc = netdev_get_num_tc(dev);
struct sched_entry *entry, *cur;
int tc;
list_for_each_entry(entry, &sched->entries, list) {
u32 gates_still_open = entry->gate_mask;
/* For each traffic class, calculate each open gate duration,
* starting at this schedule entry and ending at the schedule
* entry containing a gate close event for that TC.
*/
cur = entry;
do {
if (!gates_still_open)
break;
for (tc = 0; tc < num_tc; tc++) {
if (!(gates_still_open & BIT(tc)))
continue;
if (cur->gate_mask & BIT(tc))
entry->gate_duration[tc] += cur->interval;
else
gates_still_open &= ~BIT(tc);
}
cur = list_next_entry_circular(cur, &sched->entries, list);
} while (cur != entry);
/* Keep track of the maximum gate duration for each traffic
* class, taking care to not confuse a traffic class which is
* temporarily closed with one that is always closed.
*/
for (tc = 0; tc < num_tc; tc++)
if (entry->gate_duration[tc] &&
sched->max_open_gate_duration[tc] < entry->gate_duration[tc])
sched->max_open_gate_duration[tc] = entry->gate_duration[tc];
}
}
static bool taprio_entry_allows_tx(ktime_t skb_end_time,
struct sched_entry *entry, int tc)
{
return ktime_before(skb_end_time, entry->gate_close_time[tc]);
}
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 ktime_t taprio_mono_to_any(const struct taprio_sched *q, ktime_t mono)
{
/* This pairs with WRITE_ONCE() in taprio_parse_clockid() */
enum tk_offsets tk_offset = READ_ONCE(q->tk_offset);
switch (tk_offset) {
case TK_OFFS_MAX:
return mono;
default:
return ktime_mono_to_any(mono, tk_offset);
}
}
static ktime_t taprio_get_time(const struct taprio_sched *q)
{
return taprio_mono_to_any(q, ktime_get());
}
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;
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;
}
/* Get how much time has been already elapsed in the current cycle. */
static s32 get_cycle_time_elapsed(struct sched_gate_list *sched, ktime_t time)
{
ktime_t time_since_sched_start;
s32 time_elapsed;
time_since_sched_start = ktime_sub(time, sched->base_time);
div_s64_rem(time_since_sched_start, sched->cycle_time, &time_elapsed);
return time_elapsed;
}
static ktime_t get_interval_end_time(struct sched_gate_list *sched,
struct sched_gate_list *admin,
struct sched_entry *entry,
ktime_t intv_start)
{
s32 cycle_elapsed = get_cycle_time_elapsed(sched, intv_start);
ktime_t intv_end, cycle_ext_end, cycle_end;
cycle_end = ktime_add_ns(intv_start, sched->cycle_time - cycle_elapsed);
intv_end = ktime_add_ns(intv_start, entry->interval);
cycle_ext_end = ktime_add(cycle_end, sched->cycle_time_extension);
if (ktime_before(intv_end, cycle_end))
return intv_end;
else if (admin && admin != sched &&
ktime_after(admin->base_time, cycle_end) &&
ktime_before(admin->base_time, cycle_ext_end))
return admin->base_time;
else
return cycle_end;
}
static int length_to_duration(struct taprio_sched *q, int len)
{
return div_u64(len * atomic64_read(&q->picos_per_byte), PSEC_PER_NSEC);
}
static int duration_to_length(struct taprio_sched *q, u64 duration)
{
return div_u64(duration * PSEC_PER_NSEC, atomic64_read(&q->picos_per_byte));
}
/* Sets sched->max_sdu[] and sched->max_frm_len[] to the minimum between the
* q->max_sdu[] requested by the user and the max_sdu dynamically determined by
* the maximum open gate durations at the given link speed.
*/
static void taprio_update_queue_max_sdu(struct taprio_sched *q,
struct sched_gate_list *sched,
struct qdisc_size_table *stab)
{
struct net_device *dev = qdisc_dev(q->root);
int num_tc = netdev_get_num_tc(dev);
u32 max_sdu_from_user;
u32 max_sdu_dynamic;
u32 max_sdu;
int tc;
for (tc = 0; tc < num_tc; tc++) {
max_sdu_from_user = q->max_sdu[tc] ?: U32_MAX;
/* TC gate never closes => keep the queueMaxSDU
* selected by the user
*/
if (sched->max_open_gate_duration[tc] == sched->cycle_time) {
max_sdu_dynamic = U32_MAX;
} else {
u32 max_frm_len;
max_frm_len = duration_to_length(q, sched->max_open_gate_duration[tc]);
/* Compensate for L1 overhead from size table,
* but don't let the frame size go negative
*/
if (stab) {
max_frm_len -= stab->szopts.overhead;
max_frm_len = max_t(int, max_frm_len,
dev->hard_header_len + 1);
}
max_sdu_dynamic = max_frm_len - dev->hard_header_len;
if (max_sdu_dynamic > dev->max_mtu)
max_sdu_dynamic = U32_MAX;
}
max_sdu = min(max_sdu_dynamic, max_sdu_from_user);
if (max_sdu != U32_MAX) {
sched->max_frm_len[tc] = max_sdu + dev->hard_header_len;
sched->max_sdu[tc] = max_sdu;
} else {
sched->max_frm_len[tc] = U32_MAX; /* never oversized */
sched->max_sdu[tc] = 0;
}
}
}
/* Returns the entry corresponding to next available interval. If
* validate_interval is set, it only validates whether the timestamp occurs
* when the gate corresponding to the skb's traffic class is open.
*/
static struct sched_entry *find_entry_to_transmit(struct sk_buff *skb,
struct Qdisc *sch,
struct sched_gate_list *sched,
struct sched_gate_list *admin,
ktime_t time,
ktime_t *interval_start,
ktime_t *interval_end,
bool validate_interval)
{
ktime_t curr_intv_start, curr_intv_end, cycle_end, packet_transmit_time;
ktime_t earliest_txtime = KTIME_MAX, txtime, cycle, transmit_end_time;
struct sched_entry *entry = NULL, *entry_found = NULL;
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
bool entry_available = false;
s32 cycle_elapsed;
int tc, n;
tc = netdev_get_prio_tc_map(dev, skb->priority);
packet_transmit_time = length_to_duration(q, qdisc_pkt_len(skb));
*interval_start = 0;
*interval_end = 0;
if (!sched)
return NULL;
cycle = sched->cycle_time;
cycle_elapsed = get_cycle_time_elapsed(sched, time);
curr_intv_end = ktime_sub_ns(time, cycle_elapsed);
cycle_end = ktime_add_ns(curr_intv_end, cycle);
list_for_each_entry(entry, &sched->entries, list) {
curr_intv_start = curr_intv_end;
curr_intv_end = get_interval_end_time(sched, admin, entry,
curr_intv_start);
if (ktime_after(curr_intv_start, cycle_end))
break;
if (!(entry->gate_mask & BIT(tc)) ||
packet_transmit_time > entry->interval)
continue;
txtime = entry->next_txtime;
if (ktime_before(txtime, time) || validate_interval) {
transmit_end_time = ktime_add_ns(time, packet_transmit_time);
if ((ktime_before(curr_intv_start, time) &&
ktime_before(transmit_end_time, curr_intv_end)) ||
(ktime_after(curr_intv_start, time) && !validate_interval)) {
entry_found = entry;
*interval_start = curr_intv_start;
*interval_end = curr_intv_end;
break;
} else if (!entry_available && !validate_interval) {
/* Here, we are just trying to find out the
* first available interval in the next cycle.
*/
entry_available = true;
entry_found = entry;
*interval_start = ktime_add_ns(curr_intv_start, cycle);
*interval_end = ktime_add_ns(curr_intv_end, cycle);
}
} else if (ktime_before(txtime, earliest_txtime) &&
!entry_available) {
earliest_txtime = txtime;
entry_found = entry;
n = div_s64(ktime_sub(txtime, curr_intv_start), cycle);
*interval_start = ktime_add(curr_intv_start, n * cycle);
*interval_end = ktime_add(curr_intv_end, n * cycle);
}
}
return entry_found;
}
static bool is_valid_interval(struct sk_buff *skb, struct Qdisc *sch)
{
struct taprio_sched *q = qdisc_priv(sch);
struct sched_gate_list *sched, *admin;
ktime_t interval_start, interval_end;
struct sched_entry *entry;
rcu_read_lock();
sched = rcu_dereference(q->oper_sched);
admin = rcu_dereference(q->admin_sched);
entry = find_entry_to_transmit(skb, sch, sched, admin, skb->tstamp,
&interval_start, &interval_end, true);
rcu_read_unlock();
return entry;
}
/* This returns the tstamp value set by TCP in terms of the set clock. */
static ktime_t get_tcp_tstamp(struct taprio_sched *q, struct sk_buff *skb)
{
unsigned int offset = skb_network_offset(skb);
const struct ipv6hdr *ipv6h;
const struct iphdr *iph;
struct ipv6hdr _ipv6h;
ipv6h = skb_header_pointer(skb, offset, sizeof(_ipv6h), &_ipv6h);
if (!ipv6h)
return 0;
if (ipv6h->version == 4) {
iph = (struct iphdr *)ipv6h;
offset += iph->ihl * 4;
/* special-case 6in4 tunnelling, as that is a common way to get
* v6 connectivity in the home
*/
if (iph->protocol == IPPROTO_IPV6) {
ipv6h = skb_header_pointer(skb, offset,
sizeof(_ipv6h), &_ipv6h);
if (!ipv6h || ipv6h->nexthdr != IPPROTO_TCP)
return 0;
} else if (iph->protocol != IPPROTO_TCP) {
return 0;
}
} else if (ipv6h->version == 6 && ipv6h->nexthdr != IPPROTO_TCP) {
return 0;
}
return taprio_mono_to_any(q, skb->skb_mstamp_ns);
}
/* There are a few scenarios where we will have to modify the txtime from
* what is read from next_txtime in sched_entry. They are:
* 1. If txtime is in the past,
* a. The gate for the traffic class is currently open and packet can be
* transmitted before it closes, schedule the packet right away.
* b. If the gate corresponding to the traffic class is going to open later
* in the cycle, set the txtime of packet to the interval start.
* 2. If txtime is in the future, there are packets corresponding to the
* current traffic class waiting to be transmitted. So, the following
* possibilities exist:
* a. We can transmit the packet before the window containing the txtime
* closes.
* b. The window might close before the transmission can be completed
* successfully. So, schedule the packet in the next open window.
*/
static long get_packet_txtime(struct sk_buff *skb, struct Qdisc *sch)
{
ktime_t transmit_end_time, interval_end, interval_start, tcp_tstamp;
struct taprio_sched *q = qdisc_priv(sch);
struct sched_gate_list *sched, *admin;
ktime_t minimum_time, now, txtime;
int len, packet_transmit_time;
struct sched_entry *entry;
bool sched_changed;
now = taprio_get_time(q);
minimum_time = ktime_add_ns(now, q->txtime_delay);
tcp_tstamp = get_tcp_tstamp(q, skb);
minimum_time = max_t(ktime_t, minimum_time, tcp_tstamp);
rcu_read_lock();
admin = rcu_dereference(q->admin_sched);
sched = rcu_dereference(q->oper_sched);
if (admin && ktime_after(minimum_time, admin->base_time))
switch_schedules(q, &admin, &sched);
/* Until the schedule starts, all the queues are open */
if (!sched || ktime_before(minimum_time, sched->base_time)) {
txtime = minimum_time;
goto done;
}
len = qdisc_pkt_len(skb);
packet_transmit_time = length_to_duration(q, len);
do {
sched_changed = false;
entry = find_entry_to_transmit(skb, sch, sched, admin,
minimum_time,
&interval_start, &interval_end,
false);
if (!entry) {
txtime = 0;
goto done;
}
txtime = entry->next_txtime;
txtime = max_t(ktime_t, txtime, minimum_time);
txtime = max_t(ktime_t, txtime, interval_start);
if (admin && admin != sched &&
ktime_after(txtime, admin->base_time)) {
sched = admin;
sched_changed = true;
continue;
}
transmit_end_time = ktime_add(txtime, packet_transmit_time);
minimum_time = transmit_end_time;
/* Update the txtime of current entry to the next time it's
* interval starts.
*/
if (ktime_after(transmit_end_time, interval_end))
entry->next_txtime = ktime_add(interval_start, sched->cycle_time);
} while (sched_changed || ktime_after(transmit_end_time, interval_end));
entry->next_txtime = transmit_end_time;
done:
rcu_read_unlock();
return txtime;
}
/* Devices with full offload are expected to honor this in hardware */
static bool taprio_skb_exceeds_queue_max_sdu(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 *sched;
int prio = skb->priority;
bool exceeds = false;
u8 tc;
tc = netdev_get_prio_tc_map(dev, prio);
rcu_read_lock();
sched = rcu_dereference(q->oper_sched);
if (sched && skb->len > sched->max_frm_len[tc])
exceeds = true;
rcu_read_unlock();
return exceeds;
}
static int taprio_enqueue_one(struct sk_buff *skb, struct Qdisc *sch,
struct Qdisc *child, struct sk_buff **to_free)
{
struct taprio_sched *q = qdisc_priv(sch);
/* sk_flags are only safe to use on full sockets. */
if (skb->sk && sk_fullsock(skb->sk) && sock_flag(skb->sk, SOCK_TXTIME)) {
if (!is_valid_interval(skb, sch))
return qdisc_drop(skb, sch, to_free);
} else if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
skb->tstamp = get_packet_txtime(skb, sch);
if (!skb->tstamp)
return qdisc_drop(skb, sch, to_free);
}
qdisc_qstats_backlog_inc(sch, skb);
sch->q.qlen++;
return qdisc_enqueue(skb, child, to_free);
}
static int taprio_enqueue_segmented(struct sk_buff *skb, struct Qdisc *sch,
struct Qdisc *child,
struct sk_buff **to_free)
{
unsigned int slen = 0, numsegs = 0, len = qdisc_pkt_len(skb);
netdev_features_t features = netif_skb_features(skb);
struct sk_buff *segs, *nskb;
int ret;
segs = skb_gso_segment(skb, features & ~NETIF_F_GSO_MASK);
if (IS_ERR_OR_NULL(segs))
return qdisc_drop(skb, sch, to_free);
skb_list_walk_safe(segs, segs, nskb) {
skb_mark_not_on_list(segs);
qdisc_skb_cb(segs)->pkt_len = segs->len;
slen += segs->len;
/* FIXME: we should be segmenting to a smaller size
* rather than dropping these
*/
if (taprio_skb_exceeds_queue_max_sdu(sch, segs))
ret = qdisc_drop(segs, sch, to_free);
else
ret = taprio_enqueue_one(segs, sch, child, to_free);
if (ret != NET_XMIT_SUCCESS) {
if (net_xmit_drop_count(ret))
qdisc_qstats_drop(sch);
} else {
numsegs++;
}
}
if (numsegs > 1)
qdisc_tree_reduce_backlog(sch, 1 - numsegs, len - slen);
consume_skb(skb);
return numsegs > 0 ? NET_XMIT_SUCCESS : NET_XMIT_DROP;
}
/* Will not be called in the full offload case, since the TX queues are
* attached to the Qdisc created using qdisc_create_dflt()
*/
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);
if (taprio_skb_exceeds_queue_max_sdu(sch, skb)) {
/* Large packets might not be transmitted when the transmission
* duration exceeds any configured interval. Therefore, segment
* the skb into smaller chunks. Drivers with full offload are
* expected to handle this in hardware.
*/
if (skb_is_gso(skb))
return taprio_enqueue_segmented(skb, sch, child,
to_free);
return qdisc_drop(skb, sch, to_free);
}
return taprio_enqueue_one(skb, sch, child, to_free);
}
static struct sk_buff *taprio_peek(struct Qdisc *sch)
{
WARN_ONCE(1, "taprio only supports operating as root qdisc, peek() not implemented");
return NULL;
}
static void taprio_set_budgets(struct taprio_sched *q,
struct sched_gate_list *sched,
struct sched_entry *entry)
{
struct net_device *dev = qdisc_dev(q->root);
int num_tc = netdev_get_num_tc(dev);
int tc, budget;
for (tc = 0; tc < num_tc; tc++) {
/* Traffic classes which never close have infinite budget */
if (entry->gate_duration[tc] == sched->cycle_time)
budget = INT_MAX;
else
budget = div64_u64((u64)entry->gate_duration[tc] * PSEC_PER_NSEC,
atomic64_read(&q->picos_per_byte));
atomic_set(&entry->budget[tc], budget);
}
}
/* When an skb is sent, it consumes from the budget of all traffic classes */
static int taprio_update_budgets(struct sched_entry *entry, size_t len,
int tc_consumed, int num_tc)
{
int tc, budget, new_budget = 0;
for (tc = 0; tc < num_tc; tc++) {
budget = atomic_read(&entry->budget[tc]);
/* Don't consume from infinite budget */
if (budget == INT_MAX) {
if (tc == tc_consumed)
new_budget = budget;
continue;
}
if (tc == tc_consumed)
new_budget = atomic_sub_return(len, &entry->budget[tc]);
else
atomic_sub(len, &entry->budget[tc]);
}
return new_budget;
}
static struct sk_buff *taprio_dequeue_from_txq(struct Qdisc *sch, int txq,
struct sched_entry *entry,
u32 gate_mask)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
struct Qdisc *child = q->qdiscs[txq];
int num_tc = netdev_get_num_tc(dev);
struct sk_buff *skb;
ktime_t guard;
int prio;
int len;
u8 tc;
if (unlikely(!child))
return NULL;
if (TXTIME_ASSIST_IS_ENABLED(q->flags))
goto skip_peek_checks;
skb = child->ops->peek(child);
if (!skb)
return NULL;
prio = skb->priority;
tc = netdev_get_prio_tc_map(dev, prio);
if (!(gate_mask & BIT(tc)))
return NULL;
len = qdisc_pkt_len(skb);
guard = ktime_add_ns(taprio_get_time(q), 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 &&
!taprio_entry_allows_tx(guard, entry, tc))
return NULL;
/* ... and no budget. */
if (gate_mask != TAPRIO_ALL_GATES_OPEN &&
taprio_update_budgets(entry, len, tc, num_tc) < 0)
return NULL;
skip_peek_checks:
skb = child->ops->dequeue(child);
if (unlikely(!skb))
return NULL;
qdisc_bstats_update(sch, skb);
qdisc_qstats_backlog_dec(sch, skb);
sch->q.qlen--;
return skb;
}
static void taprio_next_tc_txq(struct net_device *dev, int tc, int *txq)
{
int offset = dev->tc_to_txq[tc].offset;
int count = dev->tc_to_txq[tc].count;
(*txq)++;
if (*txq == offset + count)
*txq = offset;
}
/* Prioritize higher traffic classes, and select among TXQs belonging to the
* same TC using round robin
*/
static struct sk_buff *taprio_dequeue_tc_priority(struct Qdisc *sch,
struct sched_entry *entry,
u32 gate_mask)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
int num_tc = netdev_get_num_tc(dev);
struct sk_buff *skb;
int tc;
for (tc = num_tc - 1; tc >= 0; tc--) {
int first_txq = q->cur_txq[tc];
if (!(gate_mask & BIT(tc)))
continue;
do {
skb = taprio_dequeue_from_txq(sch, q->cur_txq[tc],
entry, gate_mask);
taprio_next_tc_txq(dev, tc, &q->cur_txq[tc]);
if (q->cur_txq[tc] >= dev->num_tx_queues)
q->cur_txq[tc] = first_txq;
if (skb)
return skb;
} while (q->cur_txq[tc] != first_txq);
}
return NULL;
}
/* Broken way of prioritizing smaller TXQ indices and ignoring the traffic
* class other than to determine whether the gate is open or not
*/
static struct sk_buff *taprio_dequeue_txq_priority(struct Qdisc *sch,
struct sched_entry *entry,
u32 gate_mask)
{
struct net_device *dev = qdisc_dev(sch);
struct sk_buff *skb;
int i;
for (i = 0; i < dev->num_tx_queues; i++) {
skb = taprio_dequeue_from_txq(sch, i, entry, gate_mask);
if (skb)
return skb;
}
return NULL;
}
/* Will not be called in the full offload case, since the TX queues are
* attached to the Qdisc created using qdisc_create_dflt()
*/
static struct sk_buff *taprio_dequeue(struct Qdisc *sch)
{
struct taprio_sched *q = qdisc_priv(sch);
struct sk_buff *skb = NULL;
struct sched_entry *entry;
u32 gate_mask;
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
* "AdminGateStates"
*/
gate_mask = entry ? entry->gate_mask : TAPRIO_ALL_GATES_OPEN;
if (!gate_mask)
goto done;
if (static_branch_unlikely(&taprio_have_broken_mqprio) &&
!static_branch_likely(&taprio_have_working_mqprio)) {
/* Single NIC kind which is broken */
skb = taprio_dequeue_txq_priority(sch, entry, gate_mask);
} else if (static_branch_likely(&taprio_have_working_mqprio) &&
!static_branch_unlikely(&taprio_have_broken_mqprio)) {
/* Single NIC kind which prioritizes properly */
skb = taprio_dequeue_tc_priority(sch, entry, gate_mask);
} else {
/* Mixed NIC kinds present in system, need dynamic testing */
if (q->broken_mqprio)
skb = taprio_dequeue_txq_priority(sch, entry, gate_mask);
else
skb = taprio_dequeue_tc_priority(sch, entry, gate_mask);
}
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->end_time, oper->cycle_end_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 end_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 end_time would fall after
* the next schedule base_time.
*/
if (ktime_compare(next_base_time, end_time) <= 0)
return true;
/* This is the cycle_time_extension case, if the end_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(end_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 net_device *dev = qdisc_dev(q->root);
struct sched_gate_list *oper, *admin;
int num_tc = netdev_get_num_tc(dev);
struct sched_entry *entry, *next;
struct Qdisc *sch = q->root;
ktime_t end_time;
int tc;
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->end_time == oper->base_time)) {
next = list_first_entry(&oper->entries, struct sched_entry,
list);
end_time = next->end_time;
goto first_run;
}
if (should_restart_cycle(oper, entry)) {
next = list_first_entry(&oper->entries, struct sched_entry,
list);
oper->cycle_end_time = ktime_add_ns(oper->cycle_end_time,
oper->cycle_time);
} else {
next = list_next_entry(entry, list);
}
end_time = ktime_add_ns(entry->end_time, next->interval);
end_time = min_t(ktime_t, end_time, oper->cycle_end_time);
for (tc = 0; tc < num_tc; tc++) {
if (next->gate_duration[tc] == oper->cycle_time)
next->gate_close_time[tc] = KTIME_MAX;
else
next->gate_close_time[tc] = ktime_add_ns(entry->end_time,
next->gate_duration[tc]);
}
if (should_change_schedules(admin, oper, end_time)) {
/* Set things so the next time this runs, the new
* schedule runs.
*/
end_time = sched_base_time(admin);
switch_schedules(q, &admin, &oper);
}
next->end_time = end_time;
taprio_set_budgets(q, oper, next);
first_run:
rcu_assign_pointer(q->current_entry, next);
spin_unlock(&q->current_entry_lock);
hrtimer_set_expires(&q->advance_timer, end_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 taprio_tc_policy[TCA_TAPRIO_TC_ENTRY_MAX + 1] = {
[TCA_TAPRIO_TC_ENTRY_INDEX] = NLA_POLICY_MAX(NLA_U32,
TC_QOPT_MAX_QUEUE),
[TCA_TAPRIO_TC_ENTRY_MAX_SDU] = { .type = NLA_U32 },
[TCA_TAPRIO_TC_ENTRY_FP] = NLA_POLICY_RANGE(NLA_U32,
TC_FP_EXPRESS,
TC_FP_PREEMPTIBLE),
};
static const struct netlink_range_validation_signed taprio_cycle_time_range = {
.min = 0,
.max = INT_MAX,
};
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] =
NLA_POLICY_FULL_RANGE_SIGNED(NLA_S64, &taprio_cycle_time_range),
[TCA_TAPRIO_ATTR_SCHED_CYCLE_TIME_EXTENSION] = { .type = NLA_S64 },
[TCA_TAPRIO_ATTR_FLAGS] =
NLA_POLICY_MASK(NLA_U32, TAPRIO_SUPPORTED_FLAGS),
[TCA_TAPRIO_ATTR_TXTIME_DELAY] = { .type = NLA_U32 },
[TCA_TAPRIO_ATTR_TC_ENTRY] = { .type = NLA_NESTED },
};
static int fill_sched_entry(struct taprio_sched *q, struct nlattr **tb,
struct sched_entry *entry,
struct netlink_ext_ack *extack)
{
int min_duration = length_to_duration(q, ETH_ZLEN);
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]);
/* The interval should allow at least the minimum ethernet
* frame to go out.
*/
if (interval < min_duration) {
NL_SET_ERR_MSG(extack, "Invalid interval for schedule entry");
return -EINVAL;
}
entry->interval = interval;
return 0;
}
static int parse_sched_entry(struct taprio_sched *q, 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(q, tb, entry, extack);
}
static int parse_sched_list(struct taprio_sched *q, 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(q, 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 taprio_sched *q, 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(q, tb[TCA_TAPRIO_ATTR_SCHED_ENTRY_LIST],
new, extack);
if (err < 0)
return err;
if (!new->cycle_time) {
struct sched_entry *entry;
ktime_t cycle = 0;
list_for_each_entry(entry, &new->entries, list)
cycle = ktime_add_ns(cycle, entry->interval);
if (cycle < 0 || cycle > INT_MAX) {
NL_SET_ERR_MSG(extack, "'cycle_time' is too big");
return -EINVAL;
}
new->cycle_time = cycle;
}
if (new->cycle_time < new->num_entries * length_to_duration(q, ETH_ZLEN)) {
NL_SET_ERR_MSG(extack, "'cycle_time' is too small");
return -EINVAL;
}
taprio_calculate_gate_durations(q, new);
return 0;
}
static int taprio_parse_mqprio_opt(struct net_device *dev,
struct tc_mqprio_qopt *qopt,
struct netlink_ext_ack *extack,
u32 taprio_flags)
{
bool allow_overlapping_txqs = TXTIME_ASSIST_IS_ENABLED(taprio_flags);
if (!qopt) {
if (!dev->num_tc) {
NL_SET_ERR_MSG(extack, "'mqprio' configuration is necessary");
return -EINVAL;
}
return 0;
}
/* 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;
}
/* For some reason, in txtime-assist mode, we allow TXQ ranges for
* different TCs to overlap, and just validate the TXQ ranges.
*/
return mqprio_validate_qopt(dev, qopt, true, allow_overlapping_txqs,
extack);
}
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 = taprio_get_time(q);
if (ktime_after(base, now)) {
*start = base;
return 0;
}
cycle = sched->cycle_time;
/* 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_end_time(struct taprio_sched *q,
struct sched_gate_list *sched, ktime_t base)
{
struct net_device *dev = qdisc_dev(q->root);
int num_tc = netdev_get_num_tc(dev);
struct sched_entry *first;
ktime_t cycle;
int tc;
first = list_first_entry(&sched->entries,
struct sched_entry, list);
cycle = sched->cycle_time;
/* FIXME: find a better place to do this */
sched->cycle_end_time = ktime_add_ns(base, cycle);
first->end_time = ktime_add_ns(base, first->interval);
taprio_set_budgets(q, sched, first);
for (tc = 0; tc < num_tc; tc++) {
if (first->gate_duration[tc] == sched->cycle_time)
first->gate_close_time[tc] = KTIME_MAX;
else
first->gate_close_time[tc] = ktime_add_ns(base, first->gate_duration[tc]);
}
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;
if (FULL_OFFLOAD_IS_ENABLED(q->flags))
return;
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 speed = SPEED_10;
int picos_per_byte;
int err;
err = __ethtool_get_link_ksettings(dev, &ecmd);
if (err < 0)
goto skip;
if (ecmd.base.speed && ecmd.base.speed != SPEED_UNKNOWN)
speed = ecmd.base.speed;
skip:
picos_per_byte = (USEC_PER_SEC * 8) / speed;
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 sched_gate_list *oper, *admin;
struct qdisc_size_table *stab;
struct taprio_sched *q;
ASSERT_RTNL();
if (event != NETDEV_UP && event != NETDEV_CHANGE)
return NOTIFY_DONE;
list_for_each_entry(q, &taprio_list, taprio_list) {
if (dev != qdisc_dev(q->root))
continue;
taprio_set_picos_per_byte(dev, q);
stab = rtnl_dereference(q->root->stab);
oper = rtnl_dereference(q->oper_sched);
if (oper)
taprio_update_queue_max_sdu(q, oper, stab);
admin = rtnl_dereference(q->admin_sched);
if (admin)
taprio_update_queue_max_sdu(q, admin, stab);
break;
}
return NOTIFY_DONE;
}
static void setup_txtime(struct taprio_sched *q,
struct sched_gate_list *sched, ktime_t base)
{
struct sched_entry *entry;
u64 interval = 0;
list_for_each_entry(entry, &sched->entries, list) {
entry->next_txtime = ktime_add_ns(base, interval);
interval += entry->interval;
}
}
static struct tc_taprio_qopt_offload *taprio_offload_alloc(int num_entries)
{
struct __tc_taprio_qopt_offload *__offload;
__offload = kzalloc(struct_size(__offload, offload.entries, num_entries),
GFP_KERNEL);
if (!__offload)
return NULL;
refcount_set(&__offload->users, 1);
return &__offload->offload;
}
struct tc_taprio_qopt_offload *taprio_offload_get(struct tc_taprio_qopt_offload
*offload)
{
struct __tc_taprio_qopt_offload *__offload;
__offload = container_of(offload, struct __tc_taprio_qopt_offload,
offload);
refcount_inc(&__offload->users);
return offload;
}
EXPORT_SYMBOL_GPL(taprio_offload_get);
void taprio_offload_free(struct tc_taprio_qopt_offload *offload)
{
struct __tc_taprio_qopt_offload *__offload;
__offload = container_of(offload, struct __tc_taprio_qopt_offload,
offload);
if (!refcount_dec_and_test(&__offload->users))
return;
kfree(__offload);
}
EXPORT_SYMBOL_GPL(taprio_offload_free);
/* The function will only serve to keep the pointers to the "oper" and "admin"
* schedules valid in relation to their base times, so when calling dump() the
* users looks at the right schedules.
* When using full offload, the admin configuration is promoted to oper at the
* base_time in the PHC time domain. But because the system time is not
* necessarily in sync with that, we can't just trigger a hrtimer to call
* switch_schedules at the right hardware time.
* At the moment we call this by hand right away from taprio, but in the future
* it will be useful to create a mechanism for drivers to notify taprio of the
* offload state (PENDING, ACTIVE, INACTIVE) so it can be visible in dump().
* This is left as TODO.
*/
static void taprio_offload_config_changed(struct taprio_sched *q)
{
struct sched_gate_list *oper, *admin;
oper = rtnl_dereference(q->oper_sched);
admin = rtnl_dereference(q->admin_sched);
switch_schedules(q, &admin, &oper);
}
static u32 tc_map_to_queue_mask(struct net_device *dev, u32 tc_mask)
{
u32 i, queue_mask = 0;
for (i = 0; i < dev->num_tc; i++) {
u32 offset, count;
if (!(tc_mask & BIT(i)))
continue;
offset = dev->tc_to_txq[i].offset;
count = dev->tc_to_txq[i].count;
queue_mask |= GENMASK(offset + count - 1, offset);
}
return queue_mask;
}
static void taprio_sched_to_offload(struct net_device *dev,
struct sched_gate_list *sched,
struct tc_taprio_qopt_offload *offload,
const struct tc_taprio_caps *caps)
{
struct sched_entry *entry;
int i = 0;
offload->base_time = sched->base_time;
offload->cycle_time = sched->cycle_time;
offload->cycle_time_extension = sched->cycle_time_extension;
list_for_each_entry(entry, &sched->entries, list) {
struct tc_taprio_sched_entry *e = &offload->entries[i];
e->command = entry->command;
e->interval = entry->interval;
if (caps->gate_mask_per_txq)
e->gate_mask = tc_map_to_queue_mask(dev,
entry->gate_mask);
else
e->gate_mask = entry->gate_mask;
i++;
}
offload->num_entries = i;
}
static void taprio_detect_broken_mqprio(struct taprio_sched *q)
{
struct net_device *dev = qdisc_dev(q->root);
struct tc_taprio_caps caps;
qdisc_offload_query_caps(dev, TC_SETUP_QDISC_TAPRIO,
&caps, sizeof(caps));
q->broken_mqprio = caps.broken_mqprio;
if (q->broken_mqprio)
static_branch_inc(&taprio_have_broken_mqprio);
else
static_branch_inc(&taprio_have_working_mqprio);
q->detected_mqprio = true;
}
static void taprio_cleanup_broken_mqprio(struct taprio_sched *q)
{
if (!q->detected_mqprio)
return;
if (q->broken_mqprio)
static_branch_dec(&taprio_have_broken_mqprio);
else
static_branch_dec(&taprio_have_working_mqprio);
}
static int taprio_enable_offload(struct net_device *dev,
struct taprio_sched *q,
struct sched_gate_list *sched,
struct netlink_ext_ack *extack)
{
const struct net_device_ops *ops = dev->netdev_ops;
struct tc_taprio_qopt_offload *offload;
struct tc_taprio_caps caps;
int tc, err = 0;
if (!ops->ndo_setup_tc) {
NL_SET_ERR_MSG(extack,
"Device does not support taprio offload");
return -EOPNOTSUPP;
}
qdisc_offload_query_caps(dev, TC_SETUP_QDISC_TAPRIO,
&caps, sizeof(caps));
if (!caps.supports_queue_max_sdu) {
for (tc = 0; tc < TC_MAX_QUEUE; tc++) {
if (q->max_sdu[tc]) {
NL_SET_ERR_MSG_MOD(extack,
"Device does not handle queueMaxSDU");
return -EOPNOTSUPP;
}
}
}
offload = taprio_offload_alloc(sched->num_entries);
if (!offload) {
NL_SET_ERR_MSG(extack,
"Not enough memory for enabling offload mode");
return -ENOMEM;
}
offload->cmd = TAPRIO_CMD_REPLACE;
offload->extack = extack;
mqprio_qopt_reconstruct(dev, &offload->mqprio.qopt);
offload->mqprio.extack = extack;
taprio_sched_to_offload(dev, sched, offload, &caps);
mqprio_fp_to_offload(q->fp, &offload->mqprio);
for (tc = 0; tc < TC_MAX_QUEUE; tc++)
offload->max_sdu[tc] = q->max_sdu[tc];
err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TAPRIO, offload);
if (err < 0) {
NL_SET_ERR_MSG_WEAK(extack,
"Device failed to setup taprio offload");
goto done;
}
q->offloaded = true;
done:
/* The offload structure may linger around via a reference taken by the
* device driver, so clear up the netlink extack pointer so that the
* driver isn't tempted to dereference data which stopped being valid
*/
offload->extack = NULL;
offload->mqprio.extack = NULL;
taprio_offload_free(offload);
return err;
}
static int taprio_disable_offload(struct net_device *dev,
struct taprio_sched *q,
struct netlink_ext_ack *extack)
{
const struct net_device_ops *ops = dev->netdev_ops;
struct tc_taprio_qopt_offload *offload;
int err;
if (!q->offloaded)
return 0;
offload = taprio_offload_alloc(0);
if (!offload) {
NL_SET_ERR_MSG(extack,
"Not enough memory to disable offload mode");
return -ENOMEM;
}
offload->cmd = TAPRIO_CMD_DESTROY;
err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TAPRIO, offload);
if (err < 0) {
NL_SET_ERR_MSG(extack,
"Device failed to disable offload");
goto out;
}
q->offloaded = false;
out:
taprio_offload_free(offload);
return err;
}
/* If full offload is enabled, the only possible clockid is the net device's
* PHC. For that reason, specifying a clockid through netlink is incorrect.
* For txtime-assist, it is implicitly assumed that the device's PHC is kept
* in sync with the specified clockid via a user space daemon such as phc2sys.
* For both software taprio and txtime-assist, the clockid is used for the
* hrtimer that advances the schedule and hence mandatory.
*/
static int taprio_parse_clockid(struct Qdisc *sch, struct nlattr **tb,
struct netlink_ext_ack *extack)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
int err = -EINVAL;
if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
const struct ethtool_ops *ops = dev->ethtool_ops;
struct kernel_ethtool_ts_info info = {
.cmd = ETHTOOL_GET_TS_INFO,
.phc_index = -1,
};
if (tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]) {
NL_SET_ERR_MSG(extack,
"The 'clockid' cannot be specified for full offload");
goto out;
}
if (ops && ops->get_ts_info)
err = ops->get_ts_info(dev, &info);
if (err || info.phc_index < 0) {
NL_SET_ERR_MSG(extack,
"Device does not have a PTP clock");
err = -ENOTSUPP;
goto out;
}
} else if (tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]) {
int clockid = nla_get_s32(tb[TCA_TAPRIO_ATTR_SCHED_CLOCKID]);
enum tk_offsets tk_offset;
/* 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 out;
}
switch (clockid) {
case CLOCK_REALTIME:
tk_offset = TK_OFFS_REAL;
break;
case CLOCK_MONOTONIC:
tk_offset = TK_OFFS_MAX;
break;
case CLOCK_BOOTTIME:
tk_offset = TK_OFFS_BOOT;
break;
case CLOCK_TAI:
tk_offset = TK_OFFS_TAI;
break;
default:
NL_SET_ERR_MSG(extack, "Invalid 'clockid'");
err = -EINVAL;
goto out;
}
/* This pairs with READ_ONCE() in taprio_mono_to_any */
WRITE_ONCE(q->tk_offset, tk_offset);
q->clockid = clockid;
} else {
NL_SET_ERR_MSG(extack, "Specifying a 'clockid' is mandatory");
goto out;
}
/* Everything went ok, return success. */
err = 0;
out:
return err;
}
static int taprio_parse_tc_entry(struct Qdisc *sch,
struct nlattr *opt,
u32 max_sdu[TC_QOPT_MAX_QUEUE],
u32 fp[TC_QOPT_MAX_QUEUE],
unsigned long *seen_tcs,
struct netlink_ext_ack *extack)
{
struct nlattr *tb[TCA_TAPRIO_TC_ENTRY_MAX + 1] = { };
struct net_device *dev = qdisc_dev(sch);
int err, tc;
u32 val;
err = nla_parse_nested(tb, TCA_TAPRIO_TC_ENTRY_MAX, opt,
taprio_tc_policy, extack);
if (err < 0)
return err;
if (!tb[TCA_TAPRIO_TC_ENTRY_INDEX]) {
NL_SET_ERR_MSG_MOD(extack, "TC entry index missing");
return -EINVAL;
}
tc = nla_get_u32(tb[TCA_TAPRIO_TC_ENTRY_INDEX]);
if (tc >= TC_QOPT_MAX_QUEUE) {
NL_SET_ERR_MSG_MOD(extack, "TC entry index out of range");
return -ERANGE;
}
if (*seen_tcs & BIT(tc)) {
NL_SET_ERR_MSG_MOD(extack, "Duplicate TC entry");
return -EINVAL;
}
*seen_tcs |= BIT(tc);
if (tb[TCA_TAPRIO_TC_ENTRY_MAX_SDU]) {
val = nla_get_u32(tb[TCA_TAPRIO_TC_ENTRY_MAX_SDU]);
if (val > dev->max_mtu) {
NL_SET_ERR_MSG_MOD(extack, "TC max SDU exceeds device max MTU");
return -ERANGE;
}
max_sdu[tc] = val;
}
if (tb[TCA_TAPRIO_TC_ENTRY_FP])
fp[tc] = nla_get_u32(tb[TCA_TAPRIO_TC_ENTRY_FP]);
return 0;
}
static int taprio_parse_tc_entries(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);
u32 max_sdu[TC_QOPT_MAX_QUEUE];
bool have_preemption = false;
unsigned long seen_tcs = 0;
u32 fp[TC_QOPT_MAX_QUEUE];
struct nlattr *n;
int tc, rem;
int err = 0;
for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++) {
max_sdu[tc] = q->max_sdu[tc];
fp[tc] = q->fp[tc];
}
nla_for_each_nested_type(n, TCA_TAPRIO_ATTR_TC_ENTRY, opt, rem) {
err = taprio_parse_tc_entry(sch, n, max_sdu, fp, &seen_tcs,
extack);
if (err)
return err;
}
for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++) {
q->max_sdu[tc] = max_sdu[tc];
q->fp[tc] = fp[tc];
if (fp[tc] != TC_FP_EXPRESS)
have_preemption = true;
}
if (have_preemption) {
if (!FULL_OFFLOAD_IS_ENABLED(q->flags)) {
NL_SET_ERR_MSG(extack,
"Preemption only supported with full offload");
return -EOPNOTSUPP;
}
if (!ethtool_dev_mm_supported(dev)) {
NL_SET_ERR_MSG(extack,
"Device does not support preemption");
return -EOPNOTSUPP;
}
}
return err;
}
static int taprio_mqprio_cmp(const struct net_device *dev,
const struct tc_mqprio_qopt *mqprio)
{
int i;
if (!mqprio || mqprio->num_tc != dev->num_tc)
return -1;
for (i = 0; i < mqprio->num_tc; i++)
if (dev->tc_to_txq[i].count != mqprio->count[i] ||
dev->tc_to_txq[i].offset != mqprio->offset[i])
return -1;
for (i = 0; i <= TC_BITMASK; i++)
if (dev->prio_tc_map[i] != mqprio->prio_tc_map[i])
return -1;
return 0;
}
static int taprio_change(struct Qdisc *sch, struct nlattr *opt,
struct netlink_ext_ack *extack)
{
struct qdisc_size_table *stab = rtnl_dereference(sch->stab);
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;
unsigned long flags;
u32 taprio_flags;
ktime_t start;
int i, err;
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]);
/* The semantics of the 'flags' argument in relation to 'change()'
* requests, are interpreted following two rules (which are applied in
* this order): (1) an omitted 'flags' argument is interpreted as
* zero; (2) the 'flags' of a "running" taprio instance cannot be
* changed.
*/
taprio_flags = tb[TCA_TAPRIO_ATTR_FLAGS] ? nla_get_u32(tb[TCA_TAPRIO_ATTR_FLAGS]) : 0;
/* txtime-assist and full offload are mutually exclusive */
if ((taprio_flags & TCA_TAPRIO_ATTR_FLAG_TXTIME_ASSIST) &&
(taprio_flags & TCA_TAPRIO_ATTR_FLAG_FULL_OFFLOAD)) {
NL_SET_ERR_MSG_ATTR(extack, tb[TCA_TAPRIO_ATTR_FLAGS],
"TXTIME_ASSIST and FULL_OFFLOAD are mutually exclusive");
return -EINVAL;
}
if (q->flags != TAPRIO_FLAGS_INVALID && q->flags != taprio_flags) {
NL_SET_ERR_MSG_MOD(extack,
"Changing 'flags' of a running schedule is not supported");
return -EOPNOTSUPP;
}
q->flags = taprio_flags;
/* Needed for length_to_duration() during netlink attribute parsing */
taprio_set_picos_per_byte(dev, q);
err = taprio_parse_mqprio_opt(dev, mqprio, extack, q->flags);
if (err < 0)
return err;
err = taprio_parse_tc_entries(sch, opt, extack);
if (err)
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);
oper = rtnl_dereference(q->oper_sched);
admin = rtnl_dereference(q->admin_sched);
/* no changes - no new mqprio settings */
if (!taprio_mqprio_cmp(dev, mqprio))
mqprio = NULL;
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;
}
if (mqprio) {
err = netdev_set_num_tc(dev, mqprio->num_tc);
if (err)
goto free_sched;
for (i = 0; i < mqprio->num_tc; i++) {
netdev_set_tc_queue(dev, i,
mqprio->count[i],
mqprio->offset[i]);
q->cur_txq[i] = mqprio->offset[i];
}
/* Always use supplied priority mappings */
for (i = 0; i <= TC_BITMASK; i++)
netdev_set_prio_tc_map(dev, i,
mqprio->prio_tc_map[i]);
}
err = parse_taprio_schedule(q, 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;
}
err = taprio_parse_clockid(sch, tb, extack);
if (err < 0)
goto free_sched;
taprio_update_queue_max_sdu(q, new_admin, stab);
if (FULL_OFFLOAD_IS_ENABLED(q->flags))
err = taprio_enable_offload(dev, q, new_admin, extack);
else
err = taprio_disable_offload(dev, q, extack);
if (err)
goto free_sched;
/* Protects against enqueue()/dequeue() */
spin_lock_bh(qdisc_lock(sch));
if (tb[TCA_TAPRIO_ATTR_TXTIME_DELAY]) {
if (!TXTIME_ASSIST_IS_ENABLED(q->flags)) {
NL_SET_ERR_MSG_MOD(extack, "txtime-delay can only be set when txtime-assist mode is enabled");
err = -EINVAL;
goto unlock;
}
q->txtime_delay = nla_get_u32(tb[TCA_TAPRIO_ATTR_TXTIME_DELAY]);
}
if (!TXTIME_ASSIST_IS_ENABLED(q->flags) &&
!FULL_OFFLOAD_IS_ENABLED(q->flags) &&
!hrtimer_active(&q->advance_timer)) {
hrtimer_init(&q->advance_timer, q->clockid, HRTIMER_MODE_ABS);
q->advance_timer.function = advance_sched;
}
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_txtime(q, new_admin, start);
if (TXTIME_ASSIST_IS_ENABLED(q->flags)) {
if (!oper) {
rcu_assign_pointer(q->oper_sched, new_admin);
err = 0;
new_admin = NULL;
goto unlock;
}
/* Not going to race against advance_sched(), but still */
admin = rcu_replace_pointer(q->admin_sched, new_admin,
lockdep_rtnl_is_held());
if (admin)
call_rcu(&admin->rcu, taprio_free_sched_cb);
} else {
setup_first_end_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);
spin_unlock_irqrestore(&q->current_entry_lock, flags);
if (FULL_OFFLOAD_IS_ENABLED(q->flags))
taprio_offload_config_changed(q);
}
new_admin = NULL;
err = 0;
if (!stab)
NL_SET_ERR_MSG_MOD(extack,
"Size table not specified, frame length estimations may be inaccurate");
unlock:
spin_unlock_bh(qdisc_lock(sch));
free_sched:
if (new_admin)
call_rcu(&new_admin->rcu, taprio_free_sched_cb);
return err;
}
static void taprio_reset(struct Qdisc *sch)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
int i;
hrtimer_cancel(&q->advance_timer);
if (q->qdiscs) {
for (i = 0; i < dev->num_tx_queues; i++)
if (q->qdiscs[i])
qdisc_reset(q->qdiscs[i]);
}
}
static void taprio_destroy(struct Qdisc *sch)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
struct sched_gate_list *oper, *admin;
unsigned int i;
list_del(&q->taprio_list);
/* Note that taprio_reset() might not be called if an error
* happens in qdisc_create(), after taprio_init() has been called.
*/
hrtimer_cancel(&q->advance_timer);
qdisc_synchronize(sch);
taprio_disable_offload(dev, q, NULL);
if (q->qdiscs) {
for (i = 0; i < dev->num_tx_queues; i++)
qdisc_put(q->qdiscs[i]);
kfree(q->qdiscs);
}
q->qdiscs = NULL;
netdev_reset_tc(dev);
oper = rtnl_dereference(q->oper_sched);
admin = rtnl_dereference(q->admin_sched);
if (oper)
call_rcu(&oper->rcu, taprio_free_sched_cb);
if (admin)
call_rcu(&admin->rcu, taprio_free_sched_cb);
taprio_cleanup_broken_mqprio(q);
}
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, tc;
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;
q->flags = TAPRIO_FLAGS_INVALID;
list_add(&q->taprio_list, &taprio_list);
if (sch->parent != TC_H_ROOT) {
NL_SET_ERR_MSG_MOD(extack, "Can only be attached as root qdisc");
return -EOPNOTSUPP;
}
if (!netif_is_multiqueue(dev)) {
NL_SET_ERR_MSG_MOD(extack, "Multi-queue device is required");
return -EOPNOTSUPP;
}
q->qdiscs = kcalloc(dev->num_tx_queues, sizeof(q->qdiscs[0]),
GFP_KERNEL);
if (!q->qdiscs)
return -ENOMEM;
if (!opt)
return -EINVAL;
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;
}
for (tc = 0; tc < TC_QOPT_MAX_QUEUE; tc++)
q->fp[tc] = TC_FP_EXPRESS;
taprio_detect_broken_mqprio(q);
return taprio_change(sch, opt, extack);
}
static void taprio_attach(struct Qdisc *sch)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
unsigned int ntx;
/* Attach underlying qdisc */
for (ntx = 0; ntx < dev->num_tx_queues; ntx++) {
struct netdev_queue *dev_queue = netdev_get_tx_queue(dev, ntx);
struct Qdisc *old, *dev_queue_qdisc;
if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
struct Qdisc *qdisc = q->qdiscs[ntx];
/* In offload mode, the root taprio qdisc is bypassed
* and the netdev TX queues see the children directly
*/
qdisc->flags |= TCQ_F_ONETXQUEUE | TCQ_F_NOPARENT;
dev_queue_qdisc = qdisc;
} else {
/* In software mode, attach the root taprio qdisc
* to all netdev TX queues, so that dev_qdisc_enqueue()
* goes through taprio_enqueue().
*/
dev_queue_qdisc = sch;
}
old = dev_graft_qdisc(dev_queue, dev_queue_qdisc);
/* The qdisc's refcount requires to be elevated once
* for each netdev TX queue it is grafted onto
*/
qdisc_refcount_inc(dev_queue_qdisc);
if (old)
qdisc_put(old);
}
}
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);
/* In offload mode, the child Qdisc is directly attached to the netdev
* TX queue, and thus, we need to keep its refcount elevated in order
* to counteract qdisc_graft()'s call to qdisc_put() once per TX queue.
* However, save the reference to the new qdisc in the private array in
* both software and offload cases, to have an up-to-date reference to
* our children.
*/
*old = q->qdiscs[cl - 1];
if (FULL_OFFLOAD_IS_ENABLED(q->flags)) {
WARN_ON_ONCE(dev_graft_qdisc(dev_queue, new) != *old);
if (new)
qdisc_refcount_inc(new);
if (*old)
qdisc_put(*old);
}
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_tc_entries(struct sk_buff *skb,
struct taprio_sched *q,
struct sched_gate_list *sched)
{
struct nlattr *n;
int tc;
for (tc = 0; tc < TC_MAX_QUEUE; tc++) {
n = nla_nest_start(skb, TCA_TAPRIO_ATTR_TC_ENTRY);
if (!n)
return -EMSGSIZE;
if (nla_put_u32(skb, TCA_TAPRIO_TC_ENTRY_INDEX, tc))
goto nla_put_failure;
if (nla_put_u32(skb, TCA_TAPRIO_TC_ENTRY_MAX_SDU,
sched->max_sdu[tc]))
goto nla_put_failure;
if (nla_put_u32(skb, TCA_TAPRIO_TC_ENTRY_FP, q->fp[tc]))
goto nla_put_failure;
nla_nest_end(skb, n);
}
return 0;
nla_put_failure:
nla_nest_cancel(skb, n);
return -EMSGSIZE;
}
static int taprio_put_stat(struct sk_buff *skb, u64 val, u16 attrtype)
{
if (val == TAPRIO_STAT_NOT_SET)
return 0;
if (nla_put_u64_64bit(skb, attrtype, val, TCA_TAPRIO_OFFLOAD_STATS_PAD))
return -EMSGSIZE;
return 0;
}
static int taprio_dump_xstats(struct Qdisc *sch, struct gnet_dump *d,
struct tc_taprio_qopt_offload *offload,
struct tc_taprio_qopt_stats *stats)
{
struct net_device *dev = qdisc_dev(sch);
const struct net_device_ops *ops;
struct sk_buff *skb = d->skb;
struct nlattr *xstats;
int err;
ops = qdisc_dev(sch)->netdev_ops;
/* FIXME I could use qdisc_offload_dump_helper(), but that messes
* with sch->flags depending on whether the device reports taprio
* stats, and I'm not sure whether that's a good idea, considering
* that stats are optional to the offload itself
*/
if (!ops->ndo_setup_tc)
return 0;
memset(stats, 0xff, sizeof(*stats));
err = ops->ndo_setup_tc(dev, TC_SETUP_QDISC_TAPRIO, offload);
if (err == -EOPNOTSUPP)
return 0;
if (err)
return err;
xstats = nla_nest_start(skb, TCA_STATS_APP);
if (!xstats)
goto err;
if (taprio_put_stat(skb, stats->window_drops,
TCA_TAPRIO_OFFLOAD_STATS_WINDOW_DROPS) ||
taprio_put_stat(skb, stats->tx_overruns,
TCA_TAPRIO_OFFLOAD_STATS_TX_OVERRUNS))
goto err_cancel;
nla_nest_end(skb, xstats);
return 0;
err_cancel:
nla_nest_cancel(skb, xstats);
err:
return -EMSGSIZE;
}
static int taprio_dump_stats(struct Qdisc *sch, struct gnet_dump *d)
{
struct tc_taprio_qopt_offload offload = {
.cmd = TAPRIO_CMD_STATS,
};
return taprio_dump_xstats(sch, d, &offload, &offload.stats);
}
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;
oper = rtnl_dereference(q->oper_sched);
admin = rtnl_dereference(q->admin_sched);
mqprio_qopt_reconstruct(dev, &opt);
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 (!FULL_OFFLOAD_IS_ENABLED(q->flags) &&
nla_put_s32(skb, TCA_TAPRIO_ATTR_SCHED_CLOCKID, q->clockid))
goto options_error;
if (q->flags && nla_put_u32(skb, TCA_TAPRIO_ATTR_FLAGS, q->flags))
goto options_error;
if (q->txtime_delay &&
nla_put_u32(skb, TCA_TAPRIO_ATTR_TXTIME_DELAY, q->txtime_delay))
goto options_error;
if (oper && taprio_dump_tc_entries(skb, q, oper))
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:
return nla_nest_end(skb, nest);
admin_error:
nla_nest_cancel(skb, sched_nest);
options_error:
nla_nest_cancel(skb, nest);
start_error:
return -ENOSPC;
}
static struct Qdisc *taprio_leaf(struct Qdisc *sch, unsigned long cl)
{
struct taprio_sched *q = qdisc_priv(sch);
struct net_device *dev = qdisc_dev(sch);
unsigned int ntx = cl - 1;
if (ntx >= dev->num_tx_queues)
return NULL;
return q->qdiscs[ntx];
}
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 Qdisc *child = taprio_leaf(sch, cl);
tcm->tcm_parent = TC_H_ROOT;
tcm->tcm_handle |= TC_H_MIN(cl);
tcm->tcm_info = child->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 Qdisc *child = taprio_leaf(sch, cl);
struct tc_taprio_qopt_offload offload = {
.cmd = TAPRIO_CMD_QUEUE_STATS,
.queue_stats = {
.queue = cl - 1,
},
};
if (gnet_stats_copy_basic(d, NULL, &child->bstats, true) < 0 ||
qdisc_qstats_copy(d, child) < 0)
return -1;
return taprio_dump_xstats(sch, d, &offload, &offload.queue_stats.stats);
}
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 (!tc_qdisc_stats_dump(sch, ntx + 1, arg))
break;
}
}
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,
.reset = taprio_reset,
.attach = taprio_attach,
.peek = taprio_peek,
.dequeue = taprio_dequeue,
.enqueue = taprio_enqueue,
.dump = taprio_dump,
.dump_stats = taprio_dump_stats,
.owner = THIS_MODULE,
};
MODULE_ALIAS_NET_SCH("taprio");
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");
MODULE_DESCRIPTION("Time Aware Priority qdisc");
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