Commit 55edc6e6 authored by Ben Hutchings's avatar Ben Hutchings Committed by David S. Miller
Browse files

sfc: Split MAC stats DMA initiation and completion 



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: default avatarBen Hutchings <bhutchings@solarflare.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 1dfc5cea

drivers/net/sfc/efx.c

+13 −35
Original line number Diff line number Diff line
@@ -637,6 +637,7 @@ void __efx_reconfigure_port(struct efx_nic *efx) 
		netif_addr_unlock_bh(efx->net_dev);

	}



	falcon_stop_nic_stats(efx);

	falcon_deconfigure_mac_wrapper(efx);



	/* Reconfigure the PHY, disabling transmit in mac level loopback. */
@@ -651,6 +652,8 @@ void __efx_reconfigure_port(struct efx_nic *efx) 


	efx->mac_op->reconfigure(efx);



	falcon_start_nic_stats(efx);



	/* Inform kernel of loss/gain of carrier */

	efx_link_status_changed(efx);

	return;
@@ -749,7 +752,6 @@ static int efx_init_port(struct efx_nic *efx) 
	efx->mac_op->reconfigure(efx);



	efx->port_initialized = true;

	efx_stats_enable(efx);



	mutex_unlock(&efx->mac_lock);

	return 0;
@@ -802,7 +804,6 @@ static void efx_fini_port(struct efx_nic *efx) 
	if (!efx->port_initialized)

		return;



	efx_stats_disable(efx);

	efx->phy_op->fini(efx);

	efx->port_initialized = false;
@@ -1158,6 +1159,8 @@ static void efx_start_all(struct efx_nic *efx) 
	if (efx->state == STATE_RUNNING)

		queue_delayed_work(efx->workqueue, &efx->monitor_work,

				   efx_monitor_interval);



	falcon_start_nic_stats(efx);

}



/* Flush all delayed work. Should only be called when no more delayed work
@@ -1195,6 +1198,8 @@ static void efx_stop_all(struct efx_nic *efx) 
	if (!efx->port_enabled)

		return;



	falcon_stop_nic_stats(efx);



	/* Disable interrupts and wait for ISR to complete */

	falcon_disable_interrupts(efx);

	if (efx->legacy_irq)
@@ -1438,20 +1443,6 @@ static int efx_net_stop(struct net_device *net_dev) 
	return 0;

}



void efx_stats_disable(struct efx_nic *efx)

{

	spin_lock(&efx->stats_lock);

	++efx->stats_disable_count;

	spin_unlock(&efx->stats_lock);

}



void efx_stats_enable(struct efx_nic *efx)

{

	spin_lock(&efx->stats_lock);

	--efx->stats_disable_count;

	spin_unlock(&efx->stats_lock);

}



/* Context: process, dev_base_lock or RTNL held, non-blocking. */

static struct net_device_stats *efx_net_stats(struct net_device *net_dev)

{
@@ -1459,17 +1450,9 @@ static struct net_device_stats *efx_net_stats(struct net_device *net_dev) 
	struct efx_mac_stats *mac_stats = &efx->mac_stats;

	struct net_device_stats *stats = &net_dev->stats;



	/* Update stats if possible, but do not wait if another thread

	 * is updating them or if MAC stats fetches are temporarily

	 * disabled; slightly stale stats are acceptable.

	 */

	if (!spin_trylock(&efx->stats_lock))

		return stats;

	if (!efx->stats_disable_count) {

		efx->mac_op->update_stats(efx);

	spin_lock_bh(&efx->stats_lock);

	falcon_update_nic_stats(efx);

	}

	spin_unlock(&efx->stats_lock);

	spin_unlock_bh(&efx->stats_lock);



	stats->rx_packets = mac_stats->rx_packets;

	stats->tx_packets = mac_stats->tx_packets;
@@ -1726,7 +1709,6 @@ void efx_reset_down(struct efx_nic *efx, enum reset_type method, 
{

	EFX_ASSERT_RESET_SERIALISED(efx);



	efx_stats_disable(efx);

	efx_stop_all(efx);

	mutex_lock(&efx->mac_lock);

	mutex_lock(&efx->spi_lock);
@@ -1776,10 +1758,8 @@ int efx_reset_up(struct efx_nic *efx, enum reset_type method, 
	mutex_unlock(&efx->spi_lock);

	mutex_unlock(&efx->mac_lock);



	if (ok) {

	if (ok)

		efx_start_all(efx);

		efx_stats_enable(efx);

	}

	return rc;

}
@@ -1977,7 +1957,6 @@ static int efx_init_struct(struct efx_nic *efx, struct efx_nic_type *type, 
	efx->rx_checksum_enabled = true;

	spin_lock_init(&efx->netif_stop_lock);

	spin_lock_init(&efx->stats_lock);

	efx->stats_disable_count = 1;

	mutex_init(&efx->mac_lock);

	efx->mac_op = &efx_dummy_mac_operations;

	efx->phy_op = &efx_dummy_phy_operations;
@@ -2219,9 +2198,8 @@ static int __devinit efx_pci_probe(struct pci_dev *pci_dev, 
		goto fail4;

	}



	/* Switch to the running state before we expose the device to

	 * the OS.  This is to ensure that the initial gathering of

	 * MAC stats succeeds. */

	/* Switch to the running state before we expose the device to the OS,

	 * so that dev_open()|efx_start_all() will actually start the device */

	efx->state = STATE_RUNNING;



	rc = efx_register_netdev(efx);

drivers/net/sfc/efx.h

+0 −2
Original line number Diff line number Diff line
@@ -60,8 +60,6 @@ extern void efx_process_channel_now(struct efx_channel *channel); 
#define EFX_EVQ_MASK (EFX_EVQ_SIZE - 1)



/* Ports */

extern void efx_stats_disable(struct efx_nic *efx);

extern void efx_stats_enable(struct efx_nic *efx);

extern void efx_reconfigure_port(struct efx_nic *efx);

extern void __efx_reconfigure_port(struct efx_nic *efx);

drivers/net/sfc/falcon.c

+101 −30
Original line number Diff line number Diff line
@@ -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));

}



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");

	return -ETIMEDOUT;

	}

}



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);

}



/**************************************************************************

drivers/net/sfc/falcon.h

+10 −2
Original line number Diff line number Diff line
@@ -75,10 +75,18 @@ struct falcon_board { 
 * struct falcon_nic_data - Falcon NIC state

 * @pci_dev2: Secondary function of Falcon A

 * @board: Board state and functions

 * @stats_disable_count: Nest count for disabling statistics fetches

 * @stats_pending: Is there a pending DMA of MAC statistics.

 * @stats_timer: A timer for regularly fetching MAC statistics.

 * @stats_dma_done: Pointer to the flag which indicates DMA completion.

 */

struct falcon_nic_data {

	struct pci_dev *pci_dev2;

	struct falcon_board board;

	unsigned int stats_disable_count;

	bool stats_pending;

	struct timer_list stats_timer;

	u32 *stats_dma_done;

};



static inline struct falcon_board *falcon_board(struct efx_nic *efx)
@@ -128,8 +136,6 @@ extern void falcon_remove_port(struct efx_nic *efx); 
/* MAC/PHY */

extern int falcon_switch_mac(struct efx_nic *efx);

extern bool falcon_xaui_link_ok(struct efx_nic *efx);

extern int falcon_dma_stats(struct efx_nic *efx,

			    unsigned int done_offset);

extern void falcon_drain_tx_fifo(struct efx_nic *efx);

extern void falcon_deconfigure_mac_wrapper(struct efx_nic *efx);

extern void falcon_reconfigure_mac_wrapper(struct efx_nic *efx);
@@ -154,6 +160,8 @@ 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_nic(struct efx_nic *efx);

extern void falcon_update_nic_stats(struct efx_nic *efx);

extern void falcon_start_nic_stats(struct efx_nic *efx);

extern void falcon_stop_nic_stats(struct efx_nic *efx);

extern void falcon_set_multicast_hash(struct efx_nic *efx);

extern int falcon_reset_xaui(struct efx_nic *efx);

drivers/net/sfc/falcon_boards.c

+5 −5
Original line number Diff line number Diff line
@@ -347,14 +347,14 @@ static ssize_t set_phy_flash_cfg(struct device *dev, 
		 * MAC stats accordingly. */

		efx->phy_mode = new_mode;

		if (new_mode & PHY_MODE_SPECIAL)

			efx_stats_disable(efx);

			falcon_stop_nic_stats(efx);

		if (falcon_board(efx)->type->id == FALCON_BOARD_SFE4001)

			err = sfe4001_poweron(efx);

		else

			err = sfn4111t_reset(efx);

		efx_reconfigure_port(efx);

		if (!(new_mode & PHY_MODE_SPECIAL))

			efx_stats_enable(efx);

			falcon_start_nic_stats(efx);

	}

	rtnl_unlock();
@@ -441,7 +441,7 @@ static int sfe4001_init(struct efx_nic *efx) 
	if (efx->phy_mode & PHY_MODE_SPECIAL) {

		/* PHY won't generate a 156.25 MHz clock and MAC stats fetch

		 * will fail. */

		efx_stats_disable(efx);

		falcon_stop_nic_stats(efx);

	}

	rc = sfe4001_poweron(efx);

	if (rc)
@@ -504,7 +504,7 @@ static void sfn4111t_init_phy(struct efx_nic *efx) 
			return;



		efx->phy_mode = PHY_MODE_SPECIAL;

		efx_stats_disable(efx);

		falcon_stop_nic_stats(efx);

	}



	sfn4111t_reset(efx);
@@ -531,7 +531,7 @@ static int sfn4111t_init(struct efx_nic *efx) 
	if (efx->phy_mode & PHY_MODE_SPECIAL)

		/* PHY may not generate a 156.25 MHz clock and MAC

		 * stats fetch will fail. */

		efx_stats_disable(efx);

		falcon_stop_nic_stats(efx);



	return 0;

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