From 9125cdd1be1199588f71c99e76e32bcda0b7d847 Mon Sep 17 00:00:00 2001 From: Giuseppe CAVALLARO Date: Sun, 25 Nov 2012 23:10:42 +0000 Subject: [PATCH] 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: Giuseppe Cavallaro Signed-off-by: David S. Miller --- drivers/net/ethernet/stmicro/stmmac/common.h | 22 +++- drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c | 7 +- drivers/net/ethernet/stmicro/stmmac/stmmac.h | 4 + .../net/ethernet/stmicro/stmmac/stmmac_ethtool.c | 8 +- drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 132 +++++++++++++-------- 5 files changed, 111 insertions(+), 62 deletions(-) diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h index 719be39..723e903 100644 --- a/drivers/net/ethernet/stmicro/stmmac/common.h +++ b/drivers/net/ethernet/stmicro/stmmac/common.h @@ -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 { diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c b/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c index 4e0e18a..73766e6 100644 --- a/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c +++ b/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c @@ -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 & diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h index 5f89415..01b3451 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h @@ -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; diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c index 76fd61a..15cb6ee 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c @@ -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), diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c index 777234c..d9d6864 100644 --- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c +++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c @@ -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; @@ -980,6 +961,38 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv) } /** + * 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. * Description: @@ -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" - "\tskb addr %p - len: %d - nopaged_len: %d\n" - "\tn_frags: %d - ip_summed: %d - %s gso\n", - skb, skb->len, nopaged_len, nfrags, skb->ip_summed, - !skb_is_gso(skb) ? "isn't" : "is"); + 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" + "\ttx_count_frames %d\n", entry, + skb, skb->len, nopaged_len, nfrags, skb->ip_summed, + !skb_is_gso(skb) ? "isn't" : "is", + priv->tx_count_frames); #endif csum_insertion = (skb->ip_summed == CHECKSUM_PARTIAL); @@ -1212,9 +1231,9 @@ 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" - "\t\tn_frags: %d, ip_summed: %d\n", - skb->len, nopaged_len, nfrags, skb->ip_summed); + 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 priv->tx_skbuff[entry] = skb; @@ -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; } -- 2.7.4