From 127e6e10ad17585c48cba8e1dcf30d98b90ee583 Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Wed, 25 Nov 2009 16:09:55 +0000 Subject: [PATCH] sfc: Fix bugs in RX queue flushing Avoid overrunning the hardware limit of 4 concurrent RX queue flushes. Expand the queue flush state to support this. Make similar changes to TX flushing to keep the code symmetric. Signed-off-by: Ben Hutchings Signed-off-by: David S. Miller --- drivers/net/sfc/falcon.c | 103 +++++++++++++++++++++++++++---------------- drivers/net/sfc/net_driver.h | 11 ++++- 2 files changed, 73 insertions(+), 41 deletions(-) diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c index 2f1f1fc..e1b9ce3 100644 --- a/drivers/net/sfc/falcon.c +++ b/drivers/net/sfc/falcon.c @@ -109,6 +109,9 @@ MODULE_PARM_DESC(rx_xon_thresh_bytes, "RX fifo XON threshold"); /* Size and alignment of special buffers (4KB) */ #define FALCON_BUF_SIZE 4096 +/* Depth of RX flush request fifo */ +#define FALCON_RX_FLUSH_COUNT 4 + #define FALCON_IS_DUAL_FUNC(efx) \ (falcon_rev(efx) < FALCON_REV_B0) @@ -426,7 +429,7 @@ void falcon_init_tx(struct efx_tx_queue *tx_queue) efx_oword_t tx_desc_ptr; struct efx_nic *efx = tx_queue->efx; - tx_queue->flushed = false; + tx_queue->flushed = FLUSH_NONE; /* Pin TX descriptor ring */ falcon_init_special_buffer(efx, &tx_queue->txd); @@ -476,6 +479,8 @@ static void falcon_flush_tx_queue(struct efx_tx_queue *tx_queue) struct efx_nic *efx = tx_queue->efx; efx_oword_t tx_flush_descq; + tx_queue->flushed = FLUSH_PENDING; + /* Post a flush command */ EFX_POPULATE_OWORD_2(tx_flush_descq, FRF_AZ_TX_FLUSH_DESCQ_CMD, 1, @@ -489,7 +494,7 @@ void falcon_fini_tx(struct efx_tx_queue *tx_queue) efx_oword_t tx_desc_ptr; /* The queue should have been flushed */ - WARN_ON(!tx_queue->flushed); + WARN_ON(tx_queue->flushed != FLUSH_DONE); /* Remove TX descriptor ring from card */ EFX_ZERO_OWORD(tx_desc_ptr); @@ -578,7 +583,7 @@ void falcon_init_rx(struct efx_rx_queue *rx_queue) rx_queue->queue, rx_queue->rxd.index, rx_queue->rxd.index + rx_queue->rxd.entries - 1); - rx_queue->flushed = false; + rx_queue->flushed = FLUSH_NONE; /* Pin RX descriptor ring */ falcon_init_special_buffer(efx, &rx_queue->rxd); @@ -607,6 +612,8 @@ static void falcon_flush_rx_queue(struct efx_rx_queue *rx_queue) struct efx_nic *efx = rx_queue->efx; efx_oword_t rx_flush_descq; + rx_queue->flushed = FLUSH_PENDING; + /* Post a flush command */ EFX_POPULATE_OWORD_2(rx_flush_descq, FRF_AZ_RX_FLUSH_DESCQ_CMD, 1, @@ -620,7 +627,7 @@ void falcon_fini_rx(struct efx_rx_queue *rx_queue) struct efx_nic *efx = rx_queue->efx; /* The queue should already have been flushed */ - WARN_ON(!rx_queue->flushed); + WARN_ON(rx_queue->flushed != FLUSH_DONE); /* Remove RX descriptor ring from card */ EFX_ZERO_OWORD(rx_desc_ptr); @@ -1181,7 +1188,7 @@ static void falcon_poll_flush_events(struct efx_nic *efx) FSF_AZ_DRIVER_EV_SUBDATA); if (ev_queue < EFX_TX_QUEUE_COUNT) { tx_queue = efx->tx_queue + ev_queue; - tx_queue->flushed = true; + tx_queue->flushed = FLUSH_DONE; } } else if (ev_code == FSE_AZ_EV_CODE_DRIVER_EV && ev_sub_code == FSE_AZ_RX_DESCQ_FLS_DONE_EV) { @@ -1191,17 +1198,29 @@ static void falcon_poll_flush_events(struct efx_nic *efx) *event, FSF_AZ_DRIVER_EV_RX_FLUSH_FAIL); if (ev_queue < efx->n_rx_queues) { rx_queue = efx->rx_queue + ev_queue; - - /* retry the rx flush */ - if (ev_failed) - falcon_flush_rx_queue(rx_queue); - else - rx_queue->flushed = true; + rx_queue->flushed = + ev_failed ? FLUSH_FAILED : FLUSH_DONE; } } + /* We're about to destroy the queue anyway, so + * it's ok to throw away every non-flush event */ + EFX_SET_QWORD(*event); + read_ptr = (read_ptr + 1) & EFX_EVQ_MASK; } while (read_ptr != end_ptr); + + channel->eventq_read_ptr = read_ptr; +} + +static void falcon_prepare_flush(struct efx_nic *efx) +{ + falcon_deconfigure_mac_wrapper(efx); + + /* Wait for the tx and rx fifo's to get to the next packet boundary + * (~1ms without back-pressure), then to drain the remainder of the + * fifo's at data path speeds (negligible), with a healthy margin. */ + msleep(10); } /* Handle tx and rx flushes at the same time, since they run in @@ -1211,50 +1230,56 @@ int falcon_flush_queues(struct efx_nic *efx) { struct efx_rx_queue *rx_queue; struct efx_tx_queue *tx_queue; - int i; - bool outstanding; + int i, tx_pending, rx_pending; - /* Issue flush requests */ - efx_for_each_tx_queue(tx_queue, efx) { - tx_queue->flushed = false; + falcon_prepare_flush(efx); + + /* Flush all tx queues in parallel */ + efx_for_each_tx_queue(tx_queue, efx) falcon_flush_tx_queue(tx_queue); - } - efx_for_each_rx_queue(rx_queue, efx) { - rx_queue->flushed = false; - falcon_flush_rx_queue(rx_queue); - } - /* Poll the evq looking for flush completions. Since we're not pushing - * any more rx or tx descriptors at this point, we're in no danger of - * overflowing the evq whilst we wait */ + /* The hardware supports four concurrent rx flushes, each of which may + * need to be retried if there is an outstanding descriptor fetch */ for (i = 0; i < FALCON_FLUSH_POLL_COUNT; ++i) { - msleep(FALCON_FLUSH_INTERVAL); - falcon_poll_flush_events(efx); + rx_pending = tx_pending = 0; + efx_for_each_rx_queue(rx_queue, efx) { + if (rx_queue->flushed == FLUSH_PENDING) + ++rx_pending; + } + efx_for_each_rx_queue(rx_queue, efx) { + if (rx_pending == FALCON_RX_FLUSH_COUNT) + break; + if (rx_queue->flushed == FLUSH_FAILED || + rx_queue->flushed == FLUSH_NONE) { + falcon_flush_rx_queue(rx_queue); + ++rx_pending; + } + } + efx_for_each_tx_queue(tx_queue, efx) { + if (tx_queue->flushed != FLUSH_DONE) + ++tx_pending; + } - /* Check if every queue has been succesfully flushed */ - outstanding = false; - efx_for_each_tx_queue(tx_queue, efx) - outstanding |= !tx_queue->flushed; - efx_for_each_rx_queue(rx_queue, efx) - outstanding |= !rx_queue->flushed; - if (!outstanding) + if (rx_pending == 0 && tx_pending == 0) return 0; + + msleep(FALCON_FLUSH_INTERVAL); + falcon_poll_flush_events(efx); } /* Mark the queues as all flushed. We're going to return failure - * leading to a reset, or fake up success anyway. "flushed" now - * indicates that we tried to flush. */ + * leading to a reset, or fake up success anyway */ efx_for_each_tx_queue(tx_queue, efx) { - if (!tx_queue->flushed) + if (tx_queue->flushed != FLUSH_DONE) EFX_ERR(efx, "tx queue %d flush command timed out\n", tx_queue->queue); - tx_queue->flushed = true; + tx_queue->flushed = FLUSH_DONE; } efx_for_each_rx_queue(rx_queue, efx) { - if (!rx_queue->flushed) + if (rx_queue->flushed != FLUSH_DONE) EFX_ERR(efx, "rx queue %d flush command timed out\n", rx_queue->queue); - rx_queue->flushed = true; + rx_queue->flushed = FLUSH_DONE; } if (EFX_WORKAROUND_7803(efx)) diff --git a/drivers/net/sfc/net_driver.h b/drivers/net/sfc/net_driver.h index ac808d5..d0755ab 100644 --- a/drivers/net/sfc/net_driver.h +++ b/drivers/net/sfc/net_driver.h @@ -113,6 +113,13 @@ struct efx_special_buffer { int entries; }; +enum efx_flush_state { + FLUSH_NONE, + FLUSH_PENDING, + FLUSH_FAILED, + FLUSH_DONE, +}; + /** * struct efx_tx_buffer - An Efx TX buffer * @skb: The associated socket buffer. @@ -189,7 +196,7 @@ struct efx_tx_queue { struct efx_nic *nic; struct efx_tx_buffer *buffer; struct efx_special_buffer txd; - bool flushed; + enum efx_flush_state flushed; /* Members used mainly on the completion path */ unsigned int read_count ____cacheline_aligned_in_smp; @@ -284,7 +291,7 @@ struct efx_rx_queue { struct page *buf_page; dma_addr_t buf_dma_addr; char *buf_data; - bool flushed; + enum efx_flush_state flushed; }; /** -- 2.7.4