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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 <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Giuseppe CAVALLARO 2012-11-25 23:10:42 +00:00 committed by David S. Miller
parent 7284a3f1ad
commit 9125cdd1be
5 changed files with 111 additions and 62 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
drivers/net/ethernet/stmicro/stmmac/common.h
View File

@ -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 {

7
drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c
View File

@ -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 &

4
drivers/net/ethernet/stmicro/stmmac/stmmac.h
View File

@ -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;

8
drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
View File

@ -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),

132
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
View File

@ -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"
"\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;
}