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be2net: get rid of custom busy poll code
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Compared to custom busy_poll, the generic NAPI one is better, since
it allows to use GRO, and it removes a lot of code and extra locked
operations in fast path.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Sathya Perla <sathya.perla@broadcom.com>
Cc: Ajit Khaparde <ajit.khaparde@broadcom.com>
Cc: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
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Eric Dumazet authored and David S. Miller committed Feb 3, 2017
1 parent 94b5e0f commit fb6113e
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Showing 2 changed files with 9 additions and 147 deletions.
5 changes: 0 additions & 5 deletions drivers/net/ethernet/emulex/benet/be.h
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Original file line number Diff line number Diff line change
Expand Up @@ -226,11 +226,6 @@ struct be_aic_obj { /* Adaptive interrupt coalescing (AIC) info */
u64 tx_reqs_prev; /* Used to calculate TX pps */
};

enum {
NAPI_POLLING,
BUSY_POLLING
};

struct be_mcc_obj {
struct be_queue_info q;
struct be_queue_info cq;
Expand Down
151 changes: 9 additions & 142 deletions drivers/net/ethernet/emulex/benet/be_main.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -3063,7 +3063,7 @@ static inline bool do_gro(struct be_rx_compl_info *rxcp)
}

static int be_process_rx(struct be_rx_obj *rxo, struct napi_struct *napi,
int budget, int polling)
int budget)
{
struct be_adapter *adapter = rxo->adapter;
struct be_queue_info *rx_cq = &rxo->cq;
Expand Down Expand Up @@ -3095,8 +3095,7 @@ static int be_process_rx(struct be_rx_obj *rxo, struct napi_struct *napi,
goto loop_continue;
}

/* Don't do gro when we're busy_polling */
if (do_gro(rxcp) && polling != BUSY_POLLING)
if (do_gro(rxcp))
be_rx_compl_process_gro(rxo, napi, rxcp);
else
be_rx_compl_process(rxo, napi, rxcp);
Expand Down Expand Up @@ -3194,106 +3193,6 @@ static void be_process_tx(struct be_adapter *adapter, struct be_tx_obj *txo,
}
}

#ifdef CONFIG_NET_RX_BUSY_POLL
static inline bool be_lock_napi(struct be_eq_obj *eqo)
{
bool status = true;

spin_lock(&eqo->lock); /* BH is already disabled */
if (eqo->state & BE_EQ_LOCKED) {
WARN_ON(eqo->state & BE_EQ_NAPI);
eqo->state |= BE_EQ_NAPI_YIELD;
status = false;
} else {
eqo->state = BE_EQ_NAPI;
}
spin_unlock(&eqo->lock);
return status;
}

static inline void be_unlock_napi(struct be_eq_obj *eqo)
{
spin_lock(&eqo->lock); /* BH is already disabled */

WARN_ON(eqo->state & (BE_EQ_POLL | BE_EQ_NAPI_YIELD));
eqo->state = BE_EQ_IDLE;

spin_unlock(&eqo->lock);
}

static inline bool be_lock_busy_poll(struct be_eq_obj *eqo)
{
bool status = true;

spin_lock_bh(&eqo->lock);
if (eqo->state & BE_EQ_LOCKED) {
eqo->state |= BE_EQ_POLL_YIELD;
status = false;
} else {
eqo->state |= BE_EQ_POLL;
}
spin_unlock_bh(&eqo->lock);
return status;
}

static inline void be_unlock_busy_poll(struct be_eq_obj *eqo)
{
spin_lock_bh(&eqo->lock);

WARN_ON(eqo->state & (BE_EQ_NAPI));
eqo->state = BE_EQ_IDLE;

spin_unlock_bh(&eqo->lock);
}

static inline void be_enable_busy_poll(struct be_eq_obj *eqo)
{
spin_lock_init(&eqo->lock);
eqo->state = BE_EQ_IDLE;
}

static inline void be_disable_busy_poll(struct be_eq_obj *eqo)
{
local_bh_disable();

/* It's enough to just acquire napi lock on the eqo to stop
* be_busy_poll() from processing any queueus.
*/
while (!be_lock_napi(eqo))
mdelay(1);

local_bh_enable();
}

#else /* CONFIG_NET_RX_BUSY_POLL */

static inline bool be_lock_napi(struct be_eq_obj *eqo)
{
return true;
}

static inline void be_unlock_napi(struct be_eq_obj *eqo)
{
}

static inline bool be_lock_busy_poll(struct be_eq_obj *eqo)
{
return false;
}

static inline void be_unlock_busy_poll(struct be_eq_obj *eqo)
{
}

static inline void be_enable_busy_poll(struct be_eq_obj *eqo)
{
}

static inline void be_disable_busy_poll(struct be_eq_obj *eqo)
{
}
#endif /* CONFIG_NET_RX_BUSY_POLL */

int be_poll(struct napi_struct *napi, int budget)
{
struct be_eq_obj *eqo = container_of(napi, struct be_eq_obj, napi);
Expand All @@ -3308,18 +3207,13 @@ int be_poll(struct napi_struct *napi, int budget)
for_all_tx_queues_on_eq(adapter, eqo, txo, i)
be_process_tx(adapter, txo, i);

if (be_lock_napi(eqo)) {
/* This loop will iterate twice for EQ0 in which
* completions of the last RXQ (default one) are also processed
* For other EQs the loop iterates only once
*/
for_all_rx_queues_on_eq(adapter, eqo, rxo, i) {
work = be_process_rx(rxo, napi, budget, NAPI_POLLING);
max_work = max(work, max_work);
}
be_unlock_napi(eqo);
} else {
max_work = budget;
/* This loop will iterate twice for EQ0 in which
* completions of the last RXQ (default one) are also processed
* For other EQs the loop iterates only once
*/
for_all_rx_queues_on_eq(adapter, eqo, rxo, i) {
work = be_process_rx(rxo, napi, budget);
max_work = max(work, max_work);
}

if (is_mcc_eqo(eqo))
Expand All @@ -3343,28 +3237,6 @@ int be_poll(struct napi_struct *napi, int budget)
return max_work;
}

#ifdef CONFIG_NET_RX_BUSY_POLL
static int be_busy_poll(struct napi_struct *napi)
{
struct be_eq_obj *eqo = container_of(napi, struct be_eq_obj, napi);
struct be_adapter *adapter = eqo->adapter;
struct be_rx_obj *rxo;
int i, work = 0;

if (!be_lock_busy_poll(eqo))
return LL_FLUSH_BUSY;

for_all_rx_queues_on_eq(adapter, eqo, rxo, i) {
work = be_process_rx(rxo, napi, 4, BUSY_POLLING);
if (work)
break;
}

be_unlock_busy_poll(eqo);
return work;
}
#endif

void be_detect_error(struct be_adapter *adapter)
{
u32 ue_lo = 0, ue_hi = 0, ue_lo_mask = 0, ue_hi_mask = 0;
Expand Down Expand Up @@ -3669,7 +3541,6 @@ static int be_close(struct net_device *netdev)
if (adapter->flags & BE_FLAGS_NAPI_ENABLED) {
for_all_evt_queues(adapter, eqo, i) {
napi_disable(&eqo->napi);
be_disable_busy_poll(eqo);
}
adapter->flags &= ~BE_FLAGS_NAPI_ENABLED;
}
Expand Down Expand Up @@ -3839,7 +3710,6 @@ static int be_open(struct net_device *netdev)

for_all_evt_queues(adapter, eqo, i) {
napi_enable(&eqo->napi);
be_enable_busy_poll(eqo);
be_eq_notify(adapter, eqo->q.id, true, true, 0, 0);
}
adapter->flags |= BE_FLAGS_NAPI_ENABLED;
Expand Down Expand Up @@ -5245,9 +5115,6 @@ static const struct net_device_ops be_netdev_ops = {
#endif
.ndo_bridge_setlink = be_ndo_bridge_setlink,
.ndo_bridge_getlink = be_ndo_bridge_getlink,
#ifdef CONFIG_NET_RX_BUSY_POLL
.ndo_busy_poll = be_busy_poll,
#endif
.ndo_udp_tunnel_add = be_add_vxlan_port,
.ndo_udp_tunnel_del = be_del_vxlan_port,
.ndo_features_check = be_features_check,
Expand Down

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