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sfc: Split MAC stats DMA initiation and completion

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From: Steve Hodgson <shodgson@solarflare.com>

Currently we initiate MAC stats DMA and busy-wait for completion when
stats are requested.  We can improve on this with a periodic timer to
initiate and poll for stats, and opportunistically poll when stats are
requested.

Since efx_nic::stats_disable_count and efx_stats_{disable,enable}()
are Falcon-specific, rename them and move them accordingly.

Signed-off-by: Ben Hutchings <bhutchings@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Ben Hutchings
2009-11-25 16:11:35 +00:00
committed by David S. Miller
parent 1dfc5ceacd
commit 55edc6e6ff
9 changed files with 140 additions and 89 deletions
Download Patch File Download Diff File Expand all files Collapse all files

133
drivers/net/sfc/falcon.c
View File

@@ -36,8 +36,6 @@
**************************************************************************
*/
static int disable_dma_stats;
/* This is set to 16 for a good reason. In summary, if larger than
* 16, the descriptor cache holds more than a default socket
* buffer's worth of packets (for UDP we can only have at most one
@@ -1890,7 +1888,7 @@ static int falcon_reset_macs(struct efx_nic *efx)
/* MAC stats will fail whilst the TX fifo is draining. Serialise
* the drain sequence with the statistics fetch */
efx_stats_disable(efx);
falcon_stop_nic_stats(efx);
efx_reado(efx, &reg, FR_AB_MAC_CTRL);
EFX_SET_OWORD_FIELD(reg, FRF_BB_TXFIFO_DRAIN_EN, 1);
@@ -1920,13 +1918,13 @@ static int falcon_reset_macs(struct efx_nic *efx)
udelay(10);
}
efx_stats_enable(efx);
/* If we've reset the EM block and the link is up, then
* we'll have to kick the XAUI link so the PHY can recover */
if (efx->link_state.up && EFX_IS10G(efx) && EFX_WORKAROUND_5147(efx))
falcon_reset_xaui(efx);
falcon_start_nic_stats(efx);
return 0;
}
@@ -2010,25 +2008,19 @@ void falcon_reconfigure_mac_wrapper(struct efx_nic *efx)
efx_writeo(efx, &reg, FR_AZ_RX_CFG);
}
int falcon_dma_stats(struct efx_nic *efx, unsigned int done_offset)
static void falcon_stats_request(struct efx_nic *efx)
{
struct falcon_nic_data *nic_data = efx->nic_data;
efx_oword_t reg;
u32 *dma_done;
int i;
if (disable_dma_stats)
return 0;
WARN_ON(nic_data->stats_pending);
WARN_ON(nic_data->stats_disable_count);
/* Statistics fetch will fail if the MAC is in TX drain */
if (falcon_rev(efx) >= FALCON_REV_B0) {
efx_oword_t temp;
efx_reado(efx, &temp, FR_AB_MAC_CTRL);
if (EFX_OWORD_FIELD(temp, FRF_BB_TXFIFO_DRAIN_EN))
return 0;
}
if (nic_data->stats_dma_done == NULL)
return; /* no mac selected */
dma_done = (efx->stats_buffer.addr + done_offset);
*dma_done = FALCON_STATS_NOT_DONE;
*nic_data->stats_dma_done = FALCON_STATS_NOT_DONE;
nic_data->stats_pending = true;
wmb(); /* ensure done flag is clear */
/* Initiate DMA transfer of stats */
@@ -2038,17 +2030,37 @@ int falcon_dma_stats(struct efx_nic *efx, unsigned int done_offset)
efx->stats_buffer.dma_addr);
efx_writeo(efx, &reg, FR_AB_MAC_STAT_DMA);
/* Wait for transfer to complete */
for (i = 0; i < 400; i++) {
if (*(volatile u32 *)dma_done == FALCON_STATS_DONE) {
rmb(); /* Ensure the stats are valid. */
return 0;
}
udelay(10);
}
mod_timer(&nic_data->stats_timer, round_jiffies_up(jiffies + HZ / 2));
}
EFX_ERR(efx, "timed out waiting for statistics\n");
return -ETIMEDOUT;
static void falcon_stats_complete(struct efx_nic *efx)
{
struct falcon_nic_data *nic_data = efx->nic_data;
if (!nic_data->stats_pending)
return;
nic_data->stats_pending = 0;
if (*nic_data->stats_dma_done == FALCON_STATS_DONE) {
rmb(); /* read the done flag before the stats */
efx->mac_op->update_stats(efx);
} else {
EFX_ERR(efx, "timed out waiting for statistics\n");
}
}
static void falcon_stats_timer_func(unsigned long context)
{
struct efx_nic *efx = (struct efx_nic *)context;
struct falcon_nic_data *nic_data = efx->nic_data;
spin_lock(&efx->stats_lock);
falcon_stats_complete(efx);
if (nic_data->stats_disable_count == 0)
falcon_stats_request(efx);
spin_unlock(&efx->stats_lock);
}
/**************************************************************************
@@ -2206,10 +2218,12 @@ static void falcon_clock_mac(struct efx_nic *efx)
int falcon_switch_mac(struct efx_nic *efx)
{
struct efx_mac_operations *old_mac_op = efx->mac_op;
struct falcon_nic_data *nic_data = efx->nic_data;
unsigned int stats_done_offset;
int rc = 0;
/* Don't try to fetch MAC stats while we're switching MACs */
efx_stats_disable(efx);
falcon_stop_nic_stats(efx);
/* Internal loopbacks override the phy speed setting */
if (efx->loopback_mode == LOOPBACK_GMAC) {
@@ -2224,6 +2238,12 @@ int falcon_switch_mac(struct efx_nic *efx)
efx->mac_op = (EFX_IS10G(efx) ?
&falcon_xmac_operations : &falcon_gmac_operations);
if (EFX_IS10G(efx))
stats_done_offset = XgDmaDone_offset;
else
stats_done_offset = GDmaDone_offset;
nic_data->stats_dma_done = efx->stats_buffer.addr + stats_done_offset;
if (old_mac_op == efx->mac_op)
goto out;
@@ -2235,7 +2255,7 @@ int falcon_switch_mac(struct efx_nic *efx)
rc = falcon_reset_macs(efx);
out:
efx_stats_enable(efx);
falcon_start_nic_stats(efx);
return rc;
}
@@ -2900,6 +2920,10 @@ int falcon_probe_nic(struct efx_nic *efx)
goto fail6;
}
nic_data->stats_disable_count = 1;
setup_timer(&nic_data->stats_timer, &falcon_stats_timer_func,
(unsigned long)efx);
return 0;
fail6:
@@ -3125,11 +3149,58 @@ void falcon_remove_nic(struct efx_nic *efx)
void falcon_update_nic_stats(struct efx_nic *efx)
{
struct falcon_nic_data *nic_data = efx->nic_data;
efx_oword_t cnt;
if (nic_data->stats_disable_count)
return;
efx_reado(efx, &cnt, FR_AZ_RX_NODESC_DROP);
efx->n_rx_nodesc_drop_cnt +=
EFX_OWORD_FIELD(cnt, FRF_AB_RX_NODESC_DROP_CNT);
if (nic_data->stats_pending &&
*nic_data->stats_dma_done == FALCON_STATS_DONE) {
nic_data->stats_pending = false;
rmb(); /* read the done flag before the stats */
efx->mac_op->update_stats(efx);
}
}
void falcon_start_nic_stats(struct efx_nic *efx)
{
struct falcon_nic_data *nic_data = efx->nic_data;
spin_lock_bh(&efx->stats_lock);
if (--nic_data->stats_disable_count == 0)
falcon_stats_request(efx);
spin_unlock_bh(&efx->stats_lock);
}
void falcon_stop_nic_stats(struct efx_nic *efx)
{
struct falcon_nic_data *nic_data = efx->nic_data;
int i;
might_sleep();
spin_lock_bh(&efx->stats_lock);
++nic_data->stats_disable_count;
spin_unlock_bh(&efx->stats_lock);
del_timer_sync(&nic_data->stats_timer);
/* Wait enough time for the most recent transfer to
* complete. */
for (i = 0; i < 4 && nic_data->stats_pending; i++) {
if (*nic_data->stats_dma_done == FALCON_STATS_DONE)
break;
msleep(1);
}
spin_lock_bh(&efx->stats_lock);
falcon_stats_complete(efx);
spin_unlock_bh(&efx->stats_lock);
}
/**************************************************************************