diff options
Diffstat (limited to 'drivers/net/sfc/rx.c')
| -rw-r--r-- | drivers/net/sfc/rx.c | 95 |
1 files changed, 21 insertions, 74 deletions
diff --git a/drivers/net/sfc/rx.c b/drivers/net/sfc/rx.c index e308818b9f5..bf1e55e7869 100644 --- a/drivers/net/sfc/rx.c +++ b/drivers/net/sfc/rx.c @@ -276,28 +276,25 @@ static void efx_fini_rx_buffer(struct efx_rx_queue *rx_queue, /** * efx_fast_push_rx_descriptors - push new RX descriptors quickly * @rx_queue: RX descriptor queue - * @retry: Recheck the fill level * This will aim to fill the RX descriptor queue up to * @rx_queue->@fast_fill_limit. If there is insufficient atomic - * memory to do so, the caller should retry. + * memory to do so, a slow fill will be scheduled. + * + * The caller must provide serialisation (none is used here). In practise, + * this means this function must run from the NAPI handler, or be called + * when NAPI is disabled. */ -static int __efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, - int retry) +void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue) { struct efx_rx_buffer *rx_buf; unsigned fill_level, index; int i, space, rc = 0; - /* Calculate current fill level. Do this outside the lock, - * because most of the time we'll end up not wanting to do the - * fill anyway. - */ + /* Calculate current fill level, and exit if we don't need to fill */ fill_level = (rx_queue->added_count - rx_queue->removed_count); EFX_BUG_ON_PARANOID(fill_level > EFX_RXQ_SIZE); - - /* Don't fill if we don't need to */ if (fill_level >= rx_queue->fast_fill_trigger) - return 0; + return; /* Record minimum fill level */ if (unlikely(fill_level < rx_queue->min_fill)) { @@ -305,20 +302,9 @@ static int __efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, rx_queue->min_fill = fill_level; } - /* Acquire RX add lock. If this lock is contended, then a fast - * fill must already be in progress (e.g. in the refill - * tasklet), so we don't need to do anything - */ - if (!spin_trylock_bh(&rx_queue->add_lock)) - return -1; - - retry: - /* Recalculate current fill level now that we have the lock */ - fill_level = (rx_queue->added_count - rx_queue->removed_count); - EFX_BUG_ON_PARANOID(fill_level > EFX_RXQ_SIZE); space = rx_queue->fast_fill_limit - fill_level; if (space < EFX_RX_BATCH) - goto out_unlock; + return; EFX_TRACE(rx_queue->efx, "RX queue %d fast-filling descriptor ring from" " level %d to level %d using %s allocation\n", @@ -330,8 +316,13 @@ static int __efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, index = rx_queue->added_count & EFX_RXQ_MASK; rx_buf = efx_rx_buffer(rx_queue, index); rc = efx_init_rx_buffer(rx_queue, rx_buf); - if (unlikely(rc)) + if (unlikely(rc)) { + /* Ensure that we don't leave the rx queue + * empty */ + if (rx_queue->added_count == rx_queue->removed_count) + efx_schedule_slow_fill(rx_queue); goto out; + } ++rx_queue->added_count; } } while ((space -= EFX_RX_BATCH) >= EFX_RX_BATCH); @@ -343,61 +334,16 @@ static int __efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue, out: /* Send write pointer to card. */ efx_nic_notify_rx_desc(rx_queue); - - /* If the fast fill is running inside from the refill tasklet, then - * for SMP systems it may be running on a different CPU to - * RX event processing, which means that the fill level may now be - * out of date. */ - if (unlikely(retry && (rc == 0))) - goto retry; - - out_unlock: - spin_unlock_bh(&rx_queue->add_lock); - - return rc; } -/** - * efx_fast_push_rx_descriptors - push new RX descriptors quickly - * @rx_queue: RX descriptor queue - * - * This will aim to fill the RX descriptor queue up to - * @rx_queue->@fast_fill_limit. If there is insufficient memory to do so, - * it will schedule a work item to immediately continue the fast fill - */ -void efx_fast_push_rx_descriptors(struct efx_rx_queue *rx_queue) -{ - int rc; - - rc = __efx_fast_push_rx_descriptors(rx_queue, 0); - if (unlikely(rc)) { - /* Schedule the work item to run immediately. The hope is - * that work is immediately pending to free some memory - * (e.g. an RX event or TX completion) - */ - efx_schedule_slow_fill(rx_queue, 0); - } -} - -void efx_rx_work(struct work_struct *data) +void efx_rx_slow_fill(unsigned long context) { - struct efx_rx_queue *rx_queue; - int rc; - - rx_queue = container_of(data, struct efx_rx_queue, work.work); - - if (unlikely(!rx_queue->channel->enabled)) - return; - - EFX_TRACE(rx_queue->efx, "RX queue %d worker thread executing on CPU " - "%d\n", rx_queue->queue, raw_smp_processor_id()); + struct efx_rx_queue *rx_queue = (struct efx_rx_queue *)context; + struct efx_channel *channel = rx_queue->channel; + /* Post an event to cause NAPI to run and refill the queue */ + efx_nic_generate_fill_event(channel); ++rx_queue->slow_fill_count; - /* Push new RX descriptors, allowing at least 1 jiffy for - * the kernel to free some more memory. */ - rc = __efx_fast_push_rx_descriptors(rx_queue, 1); - if (rc) - efx_schedule_slow_fill(rx_queue, 1); } static void efx_rx_packet__check_len(struct efx_rx_queue *rx_queue, @@ -682,6 +628,7 @@ void efx_fini_rx_queue(struct efx_rx_queue *rx_queue) EFX_LOG(rx_queue->efx, "shutting down RX queue %d\n", rx_queue->queue); + del_timer_sync(&rx_queue->slow_fill); efx_nic_fini_rx(rx_queue); /* Release RX buffers NB start at index 0 not current HW ptr */ |