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Date: Wed, 16 Oct 2013 17:24:12 +0200
From: Jimmy Perchet <jimmy.perchet@...rot.com>
To: <peppe.cavallaro@...com>
CC: <netdev@...r.kernel.org>, Jimmy Perchet <jimmy.perchet@...rot.com>
Subject: [PATCH RFC 5/5] net:stmmac: asynchronous tx_clean
Tx descriptor's cleanup and preparation are serialized, which is not necessary
and decrease performance.
In addition TX descriptor's cleanup is performed on NET_RX softirq, this is
confusing.
This patch unserialize tx descriptor's cleanup and preparation
and defer cleanup in workqueue.
Signed-off-by: Jimmy Perchet <jimmy.perchet@...rot.com>
---
drivers/net/ethernet/stmicro/stmmac/chain_mode.c | 6 +--
drivers/net/ethernet/stmicro/stmmac/stmmac.h | 6 ++-
drivers/net/ethernet/stmicro/stmmac/stmmac_main.c | 52 +++++++++++++----------
3 files changed, 37 insertions(+), 27 deletions(-)
diff --git a/drivers/net/ethernet/stmicro/stmmac/chain_mode.c b/drivers/net/ethernet/stmicro/stmmac/chain_mode.c
index d6ed0ce..8ab83cb 100644
--- a/drivers/net/ethernet/stmicro/stmmac/chain_mode.c
+++ b/drivers/net/ethernet/stmicro/stmmac/chain_mode.c
@@ -120,7 +120,7 @@ static void stmmac_refill_desc3(void *priv_ptr, struct dma_desc *p)
* to keep explicit chaining in the descriptor.
*/
p->des3 = (unsigned int)(priv->dma_rx_phy +
- (((priv->dirty_rx) + 1) %
+ ((priv->dirty_rx + 1) %
priv->dma_rx_size) *
sizeof(struct dma_desc));
}
@@ -135,9 +135,9 @@ static void stmmac_clean_desc3(void *priv_ptr, struct dma_desc *p)
* to keep explicit chaining in the descriptor.
*/
p->des3 = (unsigned int)(priv->dma_tx_phy +
- (((priv->dirty_tx + 1) %
+ ((atomic_read(&priv->dirty_tx) + 1) %
priv->dma_tx_size) *
- sizeof(struct dma_desc)));
+ sizeof(struct dma_desc));
}
const struct stmmac_chain_mode_ops chain_mode_ops = {
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index f16a9bd..d5b8906 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -38,8 +38,8 @@ struct stmmac_priv {
struct dma_extended_desc *dma_etx ____cacheline_aligned_in_smp;
struct dma_desc *dma_tx;
struct sk_buff **tx_skbuff;
- unsigned int cur_tx;
- unsigned int dirty_tx;
+ atomic_t cur_tx;
+ atomic_t dirty_tx;
unsigned int dma_tx_size;
u32 tx_count_frames;
u32 tx_coal_frames;
@@ -106,6 +106,8 @@ struct stmmac_priv {
u32 adv_ts;
int use_riwt;
spinlock_t ptp_lock;
+ struct work_struct txclean_work;
+ struct workqueue_struct *wq;
};
extern int phyaddr;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index 5873246..de614ad 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -48,6 +48,7 @@
#include <linux/seq_file.h>
#endif /* CONFIG_STMMAC_DEBUG_FS */
#include <linux/net_tstamp.h>
+#include <linux/workqueue.h>
#include "stmmac_ptp.h"
#include "stmmac.h"
@@ -205,7 +206,8 @@ static void print_pkt(unsigned char *buf, int len)
static inline u32 stmmac_tx_avail(struct stmmac_priv *priv)
{
- return priv->dirty_tx + priv->dma_tx_size - priv->cur_tx - 1;
+ return atomic_read(&priv->dirty_tx) + priv->dma_tx_size
+ - atomic_read(&priv->cur_tx) - 1;
}
/**
@@ -230,7 +232,7 @@ static inline void stmmac_hw_fix_mac_speed(struct stmmac_priv *priv)
static void stmmac_enable_eee_mode(struct stmmac_priv *priv)
{
/* Check and enter in LPI mode */
- if ((priv->dirty_tx == priv->cur_tx) &&
+ if ((atomic_read(&priv->dirty_tx) == atomic_read(&priv->cur_tx)) &&
(priv->tx_path_in_lpi_mode == false))
priv->hw->mac->set_eee_mode(priv->ioaddr);
}
@@ -1118,8 +1120,8 @@ static int init_dma_desc_rings(struct net_device *dev)
priv->tx_skbuff[i] = NULL;
}
- priv->dirty_tx = 0;
- priv->cur_tx = 0;
+ atomic_set(&priv->dirty_tx, 0);
+ atomic_set(&priv->cur_tx, 0);
stmmac_clear_descriptors(priv);
@@ -1264,17 +1266,17 @@ static void stmmac_dma_operation_mode(int mtu, struct stmmac_priv *priv)
* @priv: driver private structure
* Description: it reclaims resources after transmission completes.
*/
-static void stmmac_tx_clean(struct stmmac_priv *priv)
+static void stmmac_tx_clean(struct work_struct *work)
{
+ struct stmmac_priv *priv =
+ container_of(work, struct stmmac_priv, txclean_work);
unsigned int txsize = priv->dma_tx_size;
- spin_lock(&priv->tx_lock);
-
priv->xstats.tx_clean++;
- while (priv->dirty_tx != priv->cur_tx) {
+ while (atomic_read(&priv->dirty_tx) != atomic_read(&priv->cur_tx)) {
int last;
- unsigned int entry = priv->dirty_tx % txsize;
+ unsigned int entry = atomic_read(&priv->dirty_tx) % txsize;
struct sk_buff *skb = priv->tx_skbuff[entry];
struct dma_desc *p;
@@ -1308,7 +1310,8 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
}
if (netif_msg_tx_done(priv))
pr_debug("%s: curr %d, dirty %d\n", __func__,
- priv->cur_tx, priv->dirty_tx);
+ atomic_read(&priv->cur_tx),
+ atomic_read(&priv->dirty_tx));
if (likely(priv->tx_skbuff_dma[entry])) {
dma_unmap_single(priv->device,
@@ -1326,7 +1329,8 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
priv->hw->desc->release_tx_desc(p, priv->mode);
- priv->dirty_tx++;
+ wmb();
+ atomic_inc(&priv->dirty_tx);
}
if (unlikely(netif_queue_stopped(priv->dev) &&
stmmac_tx_avail(priv) > STMMAC_TX_THRESH(priv))) {
@@ -1344,7 +1348,6 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
stmmac_enable_eee_mode(priv);
mod_timer(&priv->eee_ctrl_timer, STMMAC_LPI_T(eee_timer));
}
- spin_unlock(&priv->tx_lock);
}
static inline void stmmac_enable_dma_irq(struct stmmac_priv *priv)
@@ -1380,8 +1383,8 @@ static void stmmac_tx_err(struct stmmac_priv *priv)
priv->hw->desc->init_tx_desc(&priv->dma_tx[i],
priv->mode,
(i == txsize - 1));
- priv->dirty_tx = 0;
- priv->cur_tx = 0;
+ atomic_set(&priv->dirty_tx, 0);
+ atomic_set(&priv->cur_tx, 0);
priv->hw->dma->start_tx(priv->ioaddr);
priv->dev->stats.tx_errors++;
@@ -1401,12 +1404,16 @@ 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_rx)) || (status & handle_tx)) {
+ if (likely(status & handle_rx)) {
if (likely(napi_schedule_prep(&priv->napi))) {
stmmac_disable_dma_irq(priv);
__napi_schedule(&priv->napi);
}
}
+ if (likely(status & handle_tx))
+ queue_work(priv->wq, &priv->txclean_work);
+
+
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)) {
@@ -1596,8 +1603,7 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
static void stmmac_tx_timer(unsigned long data)
{
struct stmmac_priv *priv = (struct stmmac_priv *)data;
-
- stmmac_tx_clean(priv);
+ queue_work(priv->wq, &priv->txclean_work);
}
/**
@@ -1876,7 +1882,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
if (priv->tx_path_in_lpi_mode)
stmmac_disable_eee_mode(priv);
- first_entry = entry = priv->cur_tx % txsize;
+ first_entry = entry = atomic_read(&priv->cur_tx) % txsize;
csum_insertion = (skb->ip_summed == CHECKSUM_PARTIAL);
/* To program the descriptors according to the size of the frame */
@@ -1944,12 +1950,13 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
priv->hw->desc->set_tx_owner(first);
wmb();
- priv->cur_tx += nb_desc;
+ atomic_add(nb_desc, &priv->cur_tx);
if (netif_msg_pktdata(priv)) {
pr_debug("%s: curr %d dirty=%d entry=%d, first=%p, nfrags=%d",
- __func__, (priv->cur_tx % txsize),
- (priv->dirty_tx % txsize), entry, first, nfrags);
+ __func__, (atomic_read(&priv->cur_tx) % txsize),
+ (atomic_read(&priv->dirty_tx) % txsize), entry,
+ first, nfrags);
if (priv->extend_desc)
stmmac_display_ring((void *)priv->dma_etx, txsize, 1);
@@ -2171,7 +2178,6 @@ static int stmmac_poll(struct napi_struct *napi, int budget)
int work_done = 0;
priv->xstats.napi_poll++;
- stmmac_tx_clean(priv);
work_done = stmmac_rx(priv, budget);
if (work_done < budget) {
@@ -2747,6 +2753,8 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device,
spin_lock_init(&priv->lock);
spin_lock_init(&priv->tx_lock);
+ priv->wq = create_singlethread_workqueue("stmmac_wq");
+ INIT_WORK(&priv->txclean_work, stmmac_tx_clean);
ret = register_netdev(ndev);
if (ret) {
--
1.8.1.2
--
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