Commit 127e6e10 authored by Ben Hutchings's avatar Ben Hutchings Committed by David S. Miller
Browse files

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: default avatarBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 44838a44
......@@ -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))
......
......@@ -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;
};
/**
......
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