From 6bc5d3a9334401d788e1adf8b71add211265bc8b Mon Sep 17 00:00:00 2001 From: Ben Hutchings Date: Mon, 1 Sep 2008 12:49:37 +0100 Subject: [PATCH] sfc: Make queue flushes more reliable Increase the potential retry count for RX flushes from 5 to 100. Stop polling the RX_DESC_PTR_TBL to infer that a flush might have happened. Instead absolutely rely on the flush events, unless bug 7803 applies (Falcon rev A only). To keep things quick, request flushes for every TX and RX queue up front, and match up the events to requests. Signed-off-by: Ben Hutchings Signed-off-by: Jeff Garzik --- drivers/net/sfc/efx.c | 15 +-- drivers/net/sfc/falcon.c | 247 ++++++++++++++++++----------------- drivers/net/sfc/falcon.h | 1 + drivers/net/sfc/net_driver.h | 4 + 4 files changed, 141 insertions(+), 126 deletions(-) diff --git a/drivers/net/sfc/efx.c b/drivers/net/sfc/efx.c index f65e313c2be2..06ea71c7e34e 100644 --- a/drivers/net/sfc/efx.c +++ b/drivers/net/sfc/efx.c @@ -445,10 +445,17 @@ static void efx_fini_channels(struct efx_nic *efx) struct efx_channel *channel; struct efx_tx_queue *tx_queue; struct efx_rx_queue *rx_queue; + int rc; EFX_ASSERT_RESET_SERIALISED(efx); BUG_ON(efx->port_enabled); + rc = falcon_flush_queues(efx); + if (rc) + EFX_ERR(efx, "failed to flush queues\n"); + else + EFX_LOG(efx, "successfully flushed all queues\n"); + efx_for_each_channel(channel, efx) { EFX_LOG(channel->efx, "shut down chan %d\n", channel->channel); @@ -456,13 +463,6 @@ static void efx_fini_channels(struct efx_nic *efx) efx_fini_rx_queue(rx_queue); efx_for_each_channel_tx_queue(tx_queue, channel) efx_fini_tx_queue(tx_queue); - } - - /* Do the event queues last so that we can handle flush events - * for all DMA queues. */ - efx_for_each_channel(channel, efx) { - EFX_LOG(channel->efx, "shut down evq %d\n", channel->channel); - efx_fini_eventq(channel); } } @@ -1092,7 +1092,6 @@ static void efx_stop_all(struct efx_nic *efx) /* Isolate the MAC from the TX and RX engines, so that queue * flushes will complete in a timely fashion. */ - falcon_deconfigure_mac_wrapper(efx); falcon_drain_tx_fifo(efx); /* Stop the kernel transmit interface late, so the watchdog diff --git a/drivers/net/sfc/falcon.c b/drivers/net/sfc/falcon.c index ad192f82c5e6..70c681ecdabe 100644 --- a/drivers/net/sfc/falcon.c +++ b/drivers/net/sfc/falcon.c @@ -108,10 +108,10 @@ MODULE_PARM_DESC(rx_xon_thresh_bytes, "RX fifo XON threshold"); /* Max number of internal errors. After this resets will not be performed */ #define FALCON_MAX_INT_ERRORS 4 -/* Maximum period that we wait for flush events. If the flush event - * doesn't arrive in this period of time then we check if the queue - * was disabled anyway. */ -#define FALCON_FLUSH_TIMEOUT 10 /* 10ms */ +/* We poll for events every FLUSH_INTERVAL ms, and check FLUSH_POLL_COUNT times + */ +#define FALCON_FLUSH_INTERVAL 10 +#define FALCON_FLUSH_POLL_COUNT 100 /************************************************************************** * @@ -452,6 +452,8 @@ 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; + /* Pin TX descriptor ring */ falcon_init_special_buffer(efx, &tx_queue->txd); @@ -492,60 +494,16 @@ void falcon_init_tx(struct efx_tx_queue *tx_queue) } } -static int falcon_flush_tx_queue(struct efx_tx_queue *tx_queue) +static void falcon_flush_tx_queue(struct efx_tx_queue *tx_queue) { struct efx_nic *efx = tx_queue->efx; - struct efx_channel *channel = &efx->channel[0]; efx_oword_t tx_flush_descq; - unsigned int read_ptr, i; /* Post a flush command */ EFX_POPULATE_OWORD_2(tx_flush_descq, TX_FLUSH_DESCQ_CMD, 1, TX_FLUSH_DESCQ, tx_queue->queue); falcon_write(efx, &tx_flush_descq, TX_FLUSH_DESCQ_REG_KER); - msleep(FALCON_FLUSH_TIMEOUT); - - if (EFX_WORKAROUND_7803(efx)) - return 0; - - /* Look for a flush completed event */ - read_ptr = channel->eventq_read_ptr; - for (i = 0; i < FALCON_EVQ_SIZE; ++i) { - efx_qword_t *event = falcon_event(channel, read_ptr); - int ev_code, ev_sub_code, ev_queue; - if (!falcon_event_present(event)) - break; - - ev_code = EFX_QWORD_FIELD(*event, EV_CODE); - ev_sub_code = EFX_QWORD_FIELD(*event, DRIVER_EV_SUB_CODE); - ev_queue = EFX_QWORD_FIELD(*event, DRIVER_EV_TX_DESCQ_ID); - if ((ev_sub_code == TX_DESCQ_FLS_DONE_EV_DECODE) && - (ev_queue == tx_queue->queue)) { - EFX_LOG(efx, "tx queue %d flush command succesful\n", - tx_queue->queue); - return 0; - } - - read_ptr = (read_ptr + 1) & FALCON_EVQ_MASK; - } - - if (EFX_WORKAROUND_11557(efx)) { - efx_oword_t reg; - bool enabled; - - falcon_read_table(efx, ®, efx->type->txd_ptr_tbl_base, - tx_queue->queue); - enabled = EFX_OWORD_FIELD(reg, TX_DESCQ_EN); - if (!enabled) { - EFX_LOG(efx, "tx queue %d disabled without a " - "flush event seen\n", tx_queue->queue); - return 0; - } - } - - EFX_ERR(efx, "tx queue %d flush command timed out\n", tx_queue->queue); - return -ETIMEDOUT; } void falcon_fini_tx(struct efx_tx_queue *tx_queue) @@ -553,9 +511,8 @@ void falcon_fini_tx(struct efx_tx_queue *tx_queue) struct efx_nic *efx = tx_queue->efx; efx_oword_t tx_desc_ptr; - /* Stop the hardware using the queue */ - if (falcon_flush_tx_queue(tx_queue)) - EFX_ERR(efx, "failed to flush tx queue %d\n", tx_queue->queue); + /* The queue should have been flushed */ + WARN_ON(!tx_queue->flushed); /* Remove TX descriptor ring from card */ EFX_ZERO_OWORD(tx_desc_ptr); @@ -643,6 +600,8 @@ 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; + /* Pin RX descriptor ring */ falcon_init_special_buffer(efx, &rx_queue->rxd); @@ -663,11 +622,9 @@ void falcon_init_rx(struct efx_rx_queue *rx_queue) rx_queue->queue); } -static int falcon_flush_rx_queue(struct efx_rx_queue *rx_queue) +static void falcon_flush_rx_queue(struct efx_rx_queue *rx_queue) { struct efx_nic *efx = rx_queue->efx; - struct efx_channel *channel = &efx->channel[0]; - unsigned int read_ptr, i; efx_oword_t rx_flush_descq; /* Post a flush command */ @@ -675,76 +632,15 @@ static int falcon_flush_rx_queue(struct efx_rx_queue *rx_queue) RX_FLUSH_DESCQ_CMD, 1, RX_FLUSH_DESCQ, rx_queue->queue); falcon_write(efx, &rx_flush_descq, RX_FLUSH_DESCQ_REG_KER); - msleep(FALCON_FLUSH_TIMEOUT); - - if (EFX_WORKAROUND_7803(efx)) - return 0; - - /* Look for a flush completed event */ - read_ptr = channel->eventq_read_ptr; - for (i = 0; i < FALCON_EVQ_SIZE; ++i) { - efx_qword_t *event = falcon_event(channel, read_ptr); - int ev_code, ev_sub_code, ev_queue; - bool ev_failed; - if (!falcon_event_present(event)) - break; - - ev_code = EFX_QWORD_FIELD(*event, EV_CODE); - ev_sub_code = EFX_QWORD_FIELD(*event, DRIVER_EV_SUB_CODE); - ev_queue = EFX_QWORD_FIELD(*event, DRIVER_EV_RX_DESCQ_ID); - ev_failed = EFX_QWORD_FIELD(*event, DRIVER_EV_RX_FLUSH_FAIL); - - if ((ev_sub_code == RX_DESCQ_FLS_DONE_EV_DECODE) && - (ev_queue == rx_queue->queue)) { - if (ev_failed) { - EFX_INFO(efx, "rx queue %d flush command " - "failed\n", rx_queue->queue); - return -EAGAIN; - } else { - EFX_LOG(efx, "rx queue %d flush command " - "succesful\n", rx_queue->queue); - return 0; - } - } - - read_ptr = (read_ptr + 1) & FALCON_EVQ_MASK; - } - - if (EFX_WORKAROUND_11557(efx)) { - efx_oword_t reg; - bool enabled; - - falcon_read_table(efx, ®, efx->type->rxd_ptr_tbl_base, - rx_queue->queue); - enabled = EFX_OWORD_FIELD(reg, RX_DESCQ_EN); - if (!enabled) { - EFX_LOG(efx, "rx queue %d disabled without a " - "flush event seen\n", rx_queue->queue); - return 0; - } - } - - EFX_ERR(efx, "rx queue %d flush command timed out\n", rx_queue->queue); - return -ETIMEDOUT; } void falcon_fini_rx(struct efx_rx_queue *rx_queue) { efx_oword_t rx_desc_ptr; struct efx_nic *efx = rx_queue->efx; - int i, rc; - /* Try and flush the rx queue. This may need to be repeated */ - for (i = 0; i < 5; i++) { - rc = falcon_flush_rx_queue(rx_queue); - if (rc == -EAGAIN) - continue; - break; - } - if (rc) { - EFX_ERR(efx, "failed to flush rx queue %d\n", rx_queue->queue); - efx_schedule_reset(efx, RESET_TYPE_INVISIBLE); - } + /* The queue should already have been flushed */ + WARN_ON(!rx_queue->flushed); /* Remove RX descriptor ring from card */ EFX_ZERO_OWORD(rx_desc_ptr); @@ -1255,6 +1151,121 @@ void falcon_generate_test_event(struct efx_channel *channel, unsigned int magic) falcon_generate_event(channel, &test_event); } +/************************************************************************** + * + * Flush handling + * + **************************************************************************/ + + +static void falcon_poll_flush_events(struct efx_nic *efx) +{ + struct efx_channel *channel = &efx->channel[0]; + struct efx_tx_queue *tx_queue; + struct efx_rx_queue *rx_queue; + unsigned int read_ptr, i; + + read_ptr = channel->eventq_read_ptr; + for (i = 0; i < FALCON_EVQ_SIZE; ++i) { + efx_qword_t *event = falcon_event(channel, read_ptr); + int ev_code, ev_sub_code, ev_queue; + bool ev_failed; + if (!falcon_event_present(event)) + break; + + ev_code = EFX_QWORD_FIELD(*event, EV_CODE); + if (ev_code != DRIVER_EV_DECODE) + continue; + + ev_sub_code = EFX_QWORD_FIELD(*event, DRIVER_EV_SUB_CODE); + switch (ev_sub_code) { + case TX_DESCQ_FLS_DONE_EV_DECODE: + ev_queue = EFX_QWORD_FIELD(*event, + DRIVER_EV_TX_DESCQ_ID); + if (ev_queue < EFX_TX_QUEUE_COUNT) { + tx_queue = efx->tx_queue + ev_queue; + tx_queue->flushed = true; + } + break; + case RX_DESCQ_FLS_DONE_EV_DECODE: + ev_queue = EFX_QWORD_FIELD(*event, + DRIVER_EV_RX_DESCQ_ID); + ev_failed = EFX_QWORD_FIELD(*event, + 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; + } + break; + } + + read_ptr = (read_ptr + 1) & FALCON_EVQ_MASK; + } +} + +/* Handle tx and rx flushes at the same time, since they run in + * parallel in the hardware and there's no reason for us to + * serialise them */ +int falcon_flush_queues(struct efx_nic *efx) +{ + struct efx_rx_queue *rx_queue; + struct efx_tx_queue *tx_queue; + int i; + bool outstanding; + + /* Issue flush requests */ + efx_for_each_tx_queue(tx_queue, efx) { + tx_queue->flushed = false; + 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 */ + for (i = 0; i < FALCON_FLUSH_POLL_COUNT; ++i) { + msleep(FALCON_FLUSH_INTERVAL); + falcon_poll_flush_events(efx); + + /* 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) + return 0; + } + + /* 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. */ + efx_for_each_tx_queue(tx_queue, efx) { + if (!tx_queue->flushed) + EFX_ERR(efx, "tx queue %d flush command timed out\n", + tx_queue->queue); + tx_queue->flushed = true; + } + efx_for_each_rx_queue(rx_queue, efx) { + if (!rx_queue->flushed) + EFX_ERR(efx, "rx queue %d flush command timed out\n", + rx_queue->queue); + rx_queue->flushed = true; + } + + if (EFX_WORKAROUND_7803(efx)) + return 0; + + return -ETIMEDOUT; +} /************************************************************************** * diff --git a/drivers/net/sfc/falcon.h b/drivers/net/sfc/falcon.h index 30d61e48ac60..be025ba7a6c6 100644 --- a/drivers/net/sfc/falcon.h +++ b/drivers/net/sfc/falcon.h @@ -86,6 +86,7 @@ extern void falcon_fini_interrupt(struct efx_nic *efx); extern int falcon_probe_nic(struct efx_nic *efx); extern int falcon_probe_resources(struct efx_nic *efx); extern int falcon_init_nic(struct efx_nic *efx); +extern int falcon_flush_queues(struct efx_nic *efx); extern int falcon_reset_hw(struct efx_nic *efx, enum reset_type method); extern void falcon_remove_resources(struct efx_nic *efx); extern void falcon_remove_nic(struct efx_nic *efx); diff --git a/drivers/net/sfc/net_driver.h b/drivers/net/sfc/net_driver.h index be3d2ba3b74e..868ad1e703f1 100644 --- a/drivers/net/sfc/net_driver.h +++ b/drivers/net/sfc/net_driver.h @@ -160,6 +160,7 @@ struct efx_tx_buffer { * @channel: The associated channel * @buffer: The software buffer ring * @txd: The hardware descriptor ring + * @flushed: Used when handling queue flushing * @read_count: Current read pointer. * This is the number of buffers that have been removed from both rings. * @stopped: Stopped count. @@ -192,6 +193,7 @@ struct efx_tx_queue { struct efx_nic *nic; struct efx_tx_buffer *buffer; struct efx_special_buffer txd; + bool flushed; /* Members used mainly on the completion path */ unsigned int read_count ____cacheline_aligned_in_smp; @@ -260,6 +262,7 @@ struct efx_rx_buffer { * the remaining space in the allocation. * @buf_dma_addr: Page's DMA address. * @buf_data: Page's host address. + * @flushed: Use when handling queue flushing */ struct efx_rx_queue { struct efx_nic *efx; @@ -285,6 +288,7 @@ struct efx_rx_queue { struct page *buf_page; dma_addr_t buf_dma_addr; char *buf_data; + bool flushed; }; /** -- 2.30.2