Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 9125cdd1 authored by Giuseppe CAVALLARO's avatar Giuseppe CAVALLARO Committed by David S. Miller
Browse files

stmmac: add the initial tx coalesce schema 



This patch adds a new schema used for mitigating the
number of transmit interrupts.
It is based on a SW timer and a threshold value.
The timer is used to periodically call the stmmac_tx_clean
function; the threshold is used for setting the IC (Interrupt
on Completion bit). The ISR will then invoke the poll method.
Also the patch improves some ethtool stat fields.

V2: review the logic to manage the IC bit in the TDESC
that was bugged because it didn't take care about the
fragments. Also fix the tx_count_frames that has not to be
limited to TX DMA ring. Thanks to Ben Hutchings.

V3: removed the spin_lock irqsave/restore as D. Miller suggested.

Signed-off-by: default avatarGiuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 7284a3f1

drivers/net/ethernet/stmicro/stmmac/common.h

+16 −6
Original line number Diff line number Diff line
@@ -95,9 +95,12 @@ struct stmmac_extra_stats { 
	unsigned long threshold;

	unsigned long tx_pkt_n;

	unsigned long rx_pkt_n;

	unsigned long poll_n;

	unsigned long sched_timer_n;

	unsigned long normal_irq_n;

	unsigned long rx_normal_irq_n;

	unsigned long napi_poll;

	unsigned long tx_normal_irq_n;

	unsigned long tx_clean;

	unsigned long tx_reset_ic_bit;

	unsigned long mmc_tx_irq_n;

	unsigned long mmc_rx_irq_n;

	unsigned long mmc_rx_csum_offload_irq_n;
@@ -162,6 +165,12 @@ struct stmmac_extra_stats { 
#define DMA_HW_FEAT_ACTPHYIF	0x70000000 /* Active/selected PHY interface */

#define DEFAULT_DMA_PBL		8



/* Tx coalesce parameters */

#define STMMAC_COAL_TX_TIMER	40000

#define STMMAC_MAX_COAL_TX_TICK	100000

#define STMMAC_TX_MAX_FRAMES	256

#define STMMAC_TX_FRAMES	64



enum rx_frame_status { /* IPC status */

	good_frame = 0,

	discard_frame = 1,
@@ -169,10 +178,11 @@ enum rx_frame_status { /* IPC status */ 
	llc_snap = 4,

};



enum tx_dma_irq_status {

	tx_hard_error = 1,

	tx_hard_error_bump_tc = 2,

	handle_tx_rx = 3,

enum dma_irq_status {

	tx_hard_error = 0x1,

	tx_hard_error_bump_tc = 0x2,

	handle_rx = 0x4,

	handle_tx = 0x8,

};



enum core_specific_irq_mask {

drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c

+4 −3
Original line number Diff line number Diff line
@@ -206,9 +206,10 @@ int dwmac_dma_interrupt(void __iomem *ioaddr, 
	/* TX/RX NORMAL interrupts */

	if (intr_status & DMA_STATUS_NIS) {

		x->normal_irq_n++;

		if (likely((intr_status & DMA_STATUS_RI) ||

			 (intr_status & (DMA_STATUS_TI))))

				ret = handle_tx_rx;

		if (likely(intr_status & DMA_STATUS_RI))

			ret |= handle_rx;

		if (intr_status & (DMA_STATUS_TI))

			ret |= handle_tx;

	}

	/* Optional hardware blocks, interrupts should be disabled */

	if (unlikely(intr_status &

drivers/net/ethernet/stmicro/stmmac/stmmac.h

+4 −0
Original line number Diff line number Diff line
@@ -87,6 +87,10 @@ struct stmmac_priv { 
	int eee_enabled;

	int eee_active;

	int tx_lpi_timer;

	struct timer_list txtimer;

	u32 tx_count_frames;

	u32 tx_coal_frames;

	u32 tx_coal_timer;

};



extern int phyaddr;

drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c

+5 −3
Original line number Diff line number Diff line
@@ -90,10 +90,12 @@ static const struct stmmac_stats stmmac_gstrings_stats[] = { 
	STMMAC_STAT(threshold),

	STMMAC_STAT(tx_pkt_n),

	STMMAC_STAT(rx_pkt_n),

	STMMAC_STAT(poll_n),

	STMMAC_STAT(sched_timer_n),

	STMMAC_STAT(normal_irq_n),

	STMMAC_STAT(normal_irq_n),

	STMMAC_STAT(rx_normal_irq_n),

	STMMAC_STAT(napi_poll),

	STMMAC_STAT(tx_normal_irq_n),

	STMMAC_STAT(tx_clean),

	STMMAC_STAT(tx_reset_ic_bit),

	STMMAC_STAT(mmc_tx_irq_n),

	STMMAC_STAT(mmc_rx_irq_n),

	STMMAC_STAT(mmc_rx_csum_offload_irq_n),

drivers/net/ethernet/stmicro/stmmac/stmmac_main.c

+82 −50
Original line number Diff line number Diff line
@@ -137,6 +137,8 @@ static int stmmac_init_fs(struct net_device *dev); 
static void stmmac_exit_fs(void);

#endif



#define STMMAC_COAL_TIMER(x) (jiffies + usecs_to_jiffies(x))



/**

 * stmmac_verify_args - verify the driver parameters.

 * Description: it verifies if some wrong parameter is passed to the driver.
@@ -688,16 +690,18 @@ static void stmmac_dma_operation_mode(struct stmmac_priv *priv) 
}



/**

 * stmmac_tx:

 * @priv: private driver structure

 * stmmac_tx_clean:

 * @priv: private data pointer

 * Description: it reclaims resources after transmission completes.

 */

static void stmmac_tx(struct stmmac_priv *priv)

static void stmmac_tx_clean(struct stmmac_priv *priv)

{

	unsigned int txsize = priv->dma_tx_size;



	spin_lock(&priv->tx_lock);



	priv->xstats.tx_clean++;



	while (priv->dirty_tx != priv->cur_tx) {

		int last;

		unsigned int entry = priv->dirty_tx % txsize;
@@ -757,40 +761,16 @@ static void stmmac_tx(struct stmmac_priv *priv) 
	spin_unlock(&priv->tx_lock);

}



static inline void stmmac_enable_irq(struct stmmac_priv *priv)

static inline void stmmac_enable_dma_irq(struct stmmac_priv *priv)

{

	priv->hw->dma->enable_dma_irq(priv->ioaddr);

}



static inline void stmmac_disable_irq(struct stmmac_priv *priv)

static inline void stmmac_disable_dma_irq(struct stmmac_priv *priv)

{

	priv->hw->dma->disable_dma_irq(priv->ioaddr);

}



static int stmmac_has_work(struct stmmac_priv *priv)

{

	unsigned int has_work = 0;

	int rxret, tx_work = 0;



	rxret = priv->hw->desc->get_rx_owner(priv->dma_rx +

		(priv->cur_rx % priv->dma_rx_size));



	if (priv->dirty_tx != priv->cur_tx)

		tx_work = 1;



	if (likely(!rxret || tx_work))

		has_work = 1;



	return has_work;

}



static inline void _stmmac_schedule(struct stmmac_priv *priv)

{

	if (likely(stmmac_has_work(priv))) {

		stmmac_disable_irq(priv);

		napi_schedule(&priv->napi);

	}

}



/**

 * stmmac_tx_err:
@@ -813,16 +793,18 @@ static void stmmac_tx_err(struct stmmac_priv *priv) 
	netif_wake_queue(priv->dev);

}





static void stmmac_dma_interrupt(struct stmmac_priv *priv)

{

	int status;



	status = priv->hw->dma->dma_interrupt(priv->ioaddr, &priv->xstats);

	if (likely(status == handle_tx_rx))

		_stmmac_schedule(priv);



	else if (unlikely(status == tx_hard_error_bump_tc)) {

	if (likely((status & handle_rx)) || (status & handle_tx)) {

		if (likely(napi_schedule_prep(&priv->napi))) {

			stmmac_disable_dma_irq(priv);

			__napi_schedule(&priv->napi);

		}

	}

	if (unlikely(status & tx_hard_error_bump_tc)) {

		/* Try to bump up the dma threshold on this failure */

		if (unlikely(tc != SF_DMA_MODE) && (tc <= 256)) {

			tc += 64;
@@ -938,7 +920,6 @@ static int stmmac_get_hw_features(struct stmmac_priv *priv) 
		/* Alternate (enhanced) DESC mode*/

		priv->dma_cap.enh_desc =

			(hw_cap & DMA_HW_FEAT_ENHDESSEL) >> 24;



	}



	return hw_cap;
@@ -979,6 +960,38 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv) 
				   priv->dma_rx_phy);

}



/**

 * stmmac_tx_timer:

 * @data: data pointer

 * Description:

 * This is the timer handler to directly invoke the stmmac_tx_clean.

 */

static void stmmac_tx_timer(unsigned long data)

{

	struct stmmac_priv *priv = (struct stmmac_priv *)data;



	stmmac_tx_clean(priv);

}



/**

 * stmmac_tx_timer:

 * @priv: private data structure

 * Description:

 * This inits the transmit coalesce parameters: i.e. timer rate,

 * timer handler and default threshold used for enabling the

 * interrupt on completion bit.

 */

static void stmmac_init_tx_coalesce(struct stmmac_priv *priv)

{

	priv->tx_coal_frames = STMMAC_TX_FRAMES;

	priv->tx_coal_timer = STMMAC_COAL_TX_TIMER;

	init_timer(&priv->txtimer);

	priv->txtimer.expires = STMMAC_COAL_TIMER(priv->tx_coal_timer);

	priv->txtimer.data = (unsigned long)priv;

	priv->txtimer.function = stmmac_tx_timer;

	add_timer(&priv->txtimer);

}



/**

 *  stmmac_open - open entry point of the driver

 *  @dev : pointer to the device structure.
@@ -1091,6 +1104,8 @@ static int stmmac_open(struct net_device *dev) 
	priv->tx_lpi_timer = STMMAC_DEFAULT_TWT_LS_TIMER;

	priv->eee_enabled = stmmac_eee_init(priv);



	stmmac_init_tx_coalesce(priv);



	napi_enable(&priv->napi);

	netif_start_queue(dev);
@@ -1136,6 +1151,8 @@ static int stmmac_release(struct net_device *dev) 


	napi_disable(&priv->napi);



	del_timer_sync(&priv->txtimer);



	/* Free the IRQ lines */

	free_irq(dev->irq, dev);

	if (priv->wol_irq != dev->irq)
@@ -1198,11 +1215,13 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) 


#ifdef STMMAC_XMIT_DEBUG

	if ((skb->len > ETH_FRAME_LEN) || nfrags)

		pr_info("stmmac xmit:\n"

		pr_debug("stmmac xmit: [entry %d]\n"

			 "\tskb addr %p - len: %d - nopaged_len: %d\n"

		       "\tn_frags: %d - ip_summed: %d - %s gso\n",

			 "\tn_frags: %d - ip_summed: %d - %s gso\n"

			 "\ttx_count_frames %d\n", entry,

			 skb, skb->len, nopaged_len, nfrags, skb->ip_summed,

		       !skb_is_gso(skb) ? "isn't" : "is");

			 !skb_is_gso(skb) ? "isn't" : "is",

			 priv->tx_count_frames);

#endif



	csum_insertion = (skb->ip_summed == CHECKSUM_PARTIAL);
@@ -1212,7 +1231,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) 


#ifdef STMMAC_XMIT_DEBUG

	if ((nfrags > 0) || (skb->len > ETH_FRAME_LEN))

		pr_debug("stmmac xmit: skb len: %d, nopaged_len: %d,\n"

		pr_debug("\tskb len: %d, nopaged_len: %d,\n"

			 "\t\tn_frags: %d, ip_summed: %d\n",

			 skb->len, nopaged_len, nfrags, skb->ip_summed);

#endif
@@ -1245,10 +1264,24 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev) 
		wmb();

	}



	/* Interrupt on completition only for the latest segment */

	/* Finalize the latest segment. */

	priv->hw->desc->close_tx_desc(desc);



	wmb();

	/* According to the coalesce parameter the IC bit for the latest

	 * segment could be reset and the timer re-started to invoke the

	 * stmmac_tx function. This approach takes care about the fragments.

	 */

	priv->tx_count_frames += nfrags + 1;

	if (priv->tx_coal_frames > priv->tx_count_frames) {

		priv->hw->desc->clear_tx_ic(desc);

		priv->xstats.tx_reset_ic_bit++;

		TX_DBG("\t[entry %d]: tx_count_frames %d\n", entry,

		       priv->tx_count_frames);

		mod_timer(&priv->txtimer,

			  STMMAC_COAL_TIMER(priv->tx_coal_timer));

	} else

		priv->tx_count_frames = 0;



	/* To avoid raise condition */

	priv->hw->desc->set_tx_owner(first);
@@ -1419,21 +1452,20 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit) 
 *  @budget : maximum number of packets that the current CPU can receive from

 *	      all interfaces.

 *  Description :

 *   This function implements the the reception process.

 *   Also it runs the TX completion thread

 *  To look at the incoming frames and clear the tx resources.

 */

static int stmmac_poll(struct napi_struct *napi, int budget)

{

	struct stmmac_priv *priv = container_of(napi, struct stmmac_priv, napi);

	int work_done = 0;



	priv->xstats.poll_n++;

	stmmac_tx(priv);

	work_done = stmmac_rx(priv, budget);

	priv->xstats.napi_poll++;

	stmmac_tx_clean(priv);



	work_done = stmmac_rx(priv, budget);

	if (work_done < budget) {

		napi_complete(napi);

		stmmac_enable_irq(priv);

		stmmac_enable_dma_irq(priv);

	}

	return work_done;

}