sfc: set interrupt moderation via MCDI
SFN8000-series NICs require a new method of setting interrupt moderation,
via MCDI. This is indicated by a workaround flag. This new MCDI command
takes an explicit time value rather than a number of ticks. It therefore
makes sense to also store the moderation values in terms of time, since
that is what the ethtool interface is interested in.
Signed-off-by: Bert Kenward <bkenward@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/sfc/efx.c b/drivers/net/ethernet/sfc/efx.c
index 14b821b..b26e1f9 100644
--- a/drivers/net/ethernet/sfc/efx.c
+++ b/drivers/net/ethernet/sfc/efx.c
@@ -281,6 +281,27 @@
* NAPI guarantees serialisation of polls of the same device, which
* provides the guarantee required by efx_process_channel().
*/
+static void efx_update_irq_mod(struct efx_nic *efx, struct efx_channel *channel)
+{
+ int step = efx->irq_mod_step_us;
+
+ if (channel->irq_mod_score < irq_adapt_low_thresh) {
+ if (channel->irq_moderation_us > step) {
+ channel->irq_moderation_us -= step;
+ efx->type->push_irq_moderation(channel);
+ }
+ } else if (channel->irq_mod_score > irq_adapt_high_thresh) {
+ if (channel->irq_moderation_us <
+ efx->irq_rx_moderation_us) {
+ channel->irq_moderation_us += step;
+ efx->type->push_irq_moderation(channel);
+ }
+ }
+
+ channel->irq_count = 0;
+ channel->irq_mod_score = 0;
+}
+
static int efx_poll(struct napi_struct *napi, int budget)
{
struct efx_channel *channel =
@@ -301,22 +322,7 @@
if (efx_channel_has_rx_queue(channel) &&
efx->irq_rx_adaptive &&
unlikely(++channel->irq_count == 1000)) {
- if (unlikely(channel->irq_mod_score <
- irq_adapt_low_thresh)) {
- if (channel->irq_moderation > 1) {
- channel->irq_moderation -= 1;
- efx->type->push_irq_moderation(channel);
- }
- } else if (unlikely(channel->irq_mod_score >
- irq_adapt_high_thresh)) {
- if (channel->irq_moderation <
- efx->irq_rx_moderation) {
- channel->irq_moderation += 1;
- efx->type->push_irq_moderation(channel);
- }
- }
- channel->irq_count = 0;
- channel->irq_mod_score = 0;
+ efx_update_irq_mod(efx, channel);
}
efx_filter_rfs_expire(channel);
@@ -1703,6 +1709,7 @@
netif_set_real_num_rx_queues(efx->net_dev, efx->n_rx_channels);
/* Initialise the interrupt moderation settings */
+ efx->irq_mod_step_us = DIV_ROUND_UP(efx->timer_quantum_ns, 1000);
efx_init_irq_moderation(efx, tx_irq_mod_usec, rx_irq_mod_usec, true,
true);
@@ -1949,14 +1956,21 @@
* Interrupt moderation
*
**************************************************************************/
-
-static unsigned int irq_mod_ticks(unsigned int usecs, unsigned int quantum_ns)
+unsigned int efx_usecs_to_ticks(struct efx_nic *efx, unsigned int usecs)
{
if (usecs == 0)
return 0;
- if (usecs * 1000 < quantum_ns)
+ if (usecs * 1000 < efx->timer_quantum_ns)
return 1; /* never round down to 0 */
- return usecs * 1000 / quantum_ns;
+ return usecs * 1000 / efx->timer_quantum_ns;
+}
+
+unsigned int efx_ticks_to_usecs(struct efx_nic *efx, unsigned int ticks)
+{
+ /* We must round up when converting ticks to microseconds
+ * because we round down when converting the other way.
+ */
+ return DIV_ROUND_UP(ticks * efx->timer_quantum_ns, 1000);
}
/* Set interrupt moderation parameters */
@@ -1968,18 +1982,12 @@
unsigned int irq_mod_max = DIV_ROUND_UP(efx->type->timer_period_max *
efx->timer_quantum_ns,
1000);
- unsigned int tx_ticks;
- unsigned int rx_ticks;
-
EFX_ASSERT_RESET_SERIALISED(efx);
if (tx_usecs > irq_mod_max || rx_usecs > irq_mod_max)
return -EINVAL;
- tx_ticks = irq_mod_ticks(tx_usecs, efx->timer_quantum_ns);
- rx_ticks = irq_mod_ticks(rx_usecs, efx->timer_quantum_ns);
-
- if (tx_ticks != rx_ticks && efx->tx_channel_offset == 0 &&
+ if (tx_usecs != rx_usecs && efx->tx_channel_offset == 0 &&
!rx_may_override_tx) {
netif_err(efx, drv, efx->net_dev, "Channels are shared. "
"RX and TX IRQ moderation must be equal\n");
@@ -1987,12 +1995,12 @@
}
efx->irq_rx_adaptive = rx_adaptive;
- efx->irq_rx_moderation = rx_ticks;
+ efx->irq_rx_moderation_us = rx_usecs;
efx_for_each_channel(channel, efx) {
if (efx_channel_has_rx_queue(channel))
- channel->irq_moderation = rx_ticks;
+ channel->irq_moderation_us = rx_usecs;
else if (efx_channel_has_tx_queues(channel))
- channel->irq_moderation = tx_ticks;
+ channel->irq_moderation_us = tx_usecs;
}
return 0;
@@ -2001,26 +2009,21 @@
void efx_get_irq_moderation(struct efx_nic *efx, unsigned int *tx_usecs,
unsigned int *rx_usecs, bool *rx_adaptive)
{
- /* We must round up when converting ticks to microseconds
- * because we round down when converting the other way.
- */
-
*rx_adaptive = efx->irq_rx_adaptive;
- *rx_usecs = DIV_ROUND_UP(efx->irq_rx_moderation *
- efx->timer_quantum_ns,
- 1000);
+ *rx_usecs = efx->irq_rx_moderation_us;
/* If channels are shared between RX and TX, so is IRQ
* moderation. Otherwise, IRQ moderation is the same for all
* TX channels and is not adaptive.
*/
- if (efx->tx_channel_offset == 0)
+ if (efx->tx_channel_offset == 0) {
*tx_usecs = *rx_usecs;
- else
- *tx_usecs = DIV_ROUND_UP(
- efx->channel[efx->tx_channel_offset]->irq_moderation *
- efx->timer_quantum_ns,
- 1000);
+ } else {
+ struct efx_channel *tx_channel;
+
+ tx_channel = efx->channel[efx->tx_channel_offset];
+ *tx_usecs = tx_channel->irq_moderation_us;
+ }
}
/**************************************************************************