stmmac: add Rx watchdog support to mitigate the DMA irqs
GMAC devices newer than databook 3.40 has an embedded timer
that can be used for mitigating the number of interrupts.
So this patch adds this optimizations.
At any rate, the Rx watchdog can be disable (on bugged HW) by
passing from the platform the riwt_off field.
In this implementation the rx timer stored in the Reg9 is fixed
to the max value. This will be tuned by using ethtool.
V2: added a platform parameter to force to disable the rx-watchdog
for example on new core where it is bugged.
V3: do not disable NAPI when Rx watchdog is used.
V4: a new extra statistic field has been added to show the early
receive status in the interrupt handler.
This patch also adds an extra check to avoid to call
napi_schedule when the DMA_INTR_ENA_RIE bit is disabled in the
Interrupt Mask register.
Signed-off-by: Giuseppe Cavallaro <peppe.cavallaro@st.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/ethernet/stmicro/stmmac/common.h b/drivers/net/ethernet/stmicro/stmmac/common.h
index 723e903..186d148 100644
--- a/drivers/net/ethernet/stmicro/stmmac/common.h
+++ b/drivers/net/ethernet/stmicro/stmmac/common.h
@@ -48,6 +48,10 @@
#define CHIP_DBG(fmt, args...) do { } while (0)
#endif
+/* Synopsys Core versions */
+#define DWMAC_CORE_3_40 0x34
+#define DWMAC_CORE_3_50 0x35
+
#undef FRAME_FILTER_DEBUG
/* #define FRAME_FILTER_DEBUG */
@@ -81,7 +85,7 @@
unsigned long rx_missed_cntr;
unsigned long rx_overflow_cntr;
unsigned long rx_vlan;
- /* Tx/Rx IRQ errors */
+ /* Tx/Rx IRQ error info */
unsigned long tx_undeflow_irq;
unsigned long tx_process_stopped_irq;
unsigned long tx_jabber_irq;
@@ -91,7 +95,8 @@
unsigned long rx_watchdog_irq;
unsigned long tx_early_irq;
unsigned long fatal_bus_error_irq;
- /* Extra info */
+ /* Tx/Rx IRQ Events */
+ unsigned long rx_early_irq;
unsigned long threshold;
unsigned long tx_pkt_n;
unsigned long rx_pkt_n;
@@ -101,11 +106,12 @@
unsigned long tx_normal_irq_n;
unsigned long tx_clean;
unsigned long tx_reset_ic_bit;
+ unsigned long irq_receive_pmt_irq_n;
+ /* MMC info */
unsigned long mmc_tx_irq_n;
unsigned long mmc_rx_irq_n;
unsigned long mmc_rx_csum_offload_irq_n;
/* EEE */
- unsigned long irq_receive_pmt_irq_n;
unsigned long irq_tx_path_in_lpi_mode_n;
unsigned long irq_tx_path_exit_lpi_mode_n;
unsigned long irq_rx_path_in_lpi_mode_n;
@@ -165,6 +171,9 @@
#define DMA_HW_FEAT_ACTPHYIF 0x70000000 /* Active/selected PHY interface */
#define DEFAULT_DMA_PBL 8
+/* Max/Min RI Watchdog Timer count value */
+#define MAX_DMA_RIWT 0xff
+#define MIN_DMA_RIWT 0x20
/* Tx coalesce parameters */
#define STMMAC_COAL_TX_TIMER 40000
#define STMMAC_MAX_COAL_TX_TICK 100000
@@ -306,6 +315,8 @@
struct stmmac_extra_stats *x);
/* If supported then get the optional core features */
unsigned int (*get_hw_feature) (void __iomem *ioaddr);
+ /* Program the HW RX Watchdog */
+ void (*rx_watchdog) (void __iomem *ioaddr, u32 riwt);
};
struct stmmac_ops {
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
index 0e4cace..7ad56af 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000.h
@@ -230,8 +230,5 @@
#define GMAC_MMC_TX_INTR 0x108
#define GMAC_MMC_RX_CSUM_OFFLOAD 0x208
-/* Synopsys Core versions */
-#define DWMAC_CORE_3_40 0x34
-
extern const struct stmmac_dma_ops dwmac1000_dma_ops;
#endif /* __DWMAC1000_H__ */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
index 0335000..bf83c03 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac1000_dma.c
@@ -174,6 +174,11 @@
return readl(ioaddr + DMA_HW_FEATURE);
}
+static void dwmac1000_rx_watchdog(void __iomem *ioaddr, u32 riwt)
+{
+ writel(riwt, ioaddr + DMA_RX_WATCHDOG);
+}
+
const struct stmmac_dma_ops dwmac1000_dma_ops = {
.init = dwmac1000_dma_init,
.dump_regs = dwmac1000_dump_dma_regs,
@@ -187,4 +192,5 @@
.stop_rx = dwmac_dma_stop_rx,
.dma_interrupt = dwmac_dma_interrupt,
.get_hw_feature = dwmac1000_get_hw_feature,
+ .rx_watchdog = dwmac1000_rx_watchdog,
};
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h b/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h
index e49c9a0..807f303 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac_dma.h
@@ -35,7 +35,10 @@
#define DMA_CONTROL 0x00001018 /* Ctrl (Operational Mode) */
#define DMA_INTR_ENA 0x0000101c /* Interrupt Enable */
#define DMA_MISSED_FRAME_CTR 0x00001020 /* Missed Frame Counter */
-#define DMA_AXI_BUS_MODE 0x00001028 /* AXI Bus Mode */
+/* Rx watchdog register */
+#define DMA_RX_WATCHDOG 0x00001024
+/* AXI Bus Mode */
+#define DMA_AXI_BUS_MODE 0x00001028
#define DMA_CUR_TX_BUF_ADDR 0x00001050 /* Current Host Tx Buffer */
#define DMA_CUR_RX_BUF_ADDR 0x00001054 /* Current Host Rx Buffer */
#define DMA_HW_FEATURE 0x00001058 /* HW Feature Register */
diff --git a/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c b/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c
index 73766e6..491d7e9 100644
--- a/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c
+++ b/drivers/net/ethernet/stmicro/stmmac/dwmac_lib.c
@@ -204,17 +204,28 @@
}
}
/* TX/RX NORMAL interrupts */
- if (intr_status & DMA_STATUS_NIS) {
+ if (likely(intr_status & DMA_STATUS_NIS)) {
x->normal_irq_n++;
- if (likely(intr_status & DMA_STATUS_RI))
- ret |= handle_rx;
- if (intr_status & (DMA_STATUS_TI))
+ if (likely(intr_status & DMA_STATUS_RI)) {
+ u32 value = readl(ioaddr + DMA_INTR_ENA);
+ /* to schedule NAPI on real RIE event. */
+ if (likely(value & DMA_INTR_ENA_RIE)) {
+ x->rx_normal_irq_n++;
+ ret |= handle_rx;
+ }
+ }
+ if (likely(intr_status & DMA_STATUS_TI)) {
+ x->tx_normal_irq_n++;
ret |= handle_tx;
+ }
+ if (unlikely(intr_status & DMA_STATUS_ERI))
+ x->rx_early_irq++;
}
/* Optional hardware blocks, interrupts should be disabled */
if (unlikely(intr_status &
(DMA_STATUS_GPI | DMA_STATUS_GMI | DMA_STATUS_GLI)))
pr_info("%s: unexpected status %08x\n", __func__, intr_status);
+
/* Clear the interrupt by writing a logic 1 to the CSR5[15-0] */
writel((intr_status & 0x1ffff), ioaddr + DMA_STATUS);
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac.h b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
index 01b3451..fe0535c 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac.h
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac.h
@@ -91,6 +91,8 @@
u32 tx_count_frames;
u32 tx_coal_frames;
u32 tx_coal_timer;
+ int use_riwt;
+ u32 rx_riwt;
};
extern int phyaddr;
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
index 15cb6ee..7f7ccd2 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_ethtool.c
@@ -76,7 +76,7 @@
STMMAC_STAT(rx_missed_cntr),
STMMAC_STAT(rx_overflow_cntr),
STMMAC_STAT(rx_vlan),
- /* Tx/Rx IRQ errors */
+ /* Tx/Rx IRQ error info */
STMMAC_STAT(tx_undeflow_irq),
STMMAC_STAT(tx_process_stopped_irq),
STMMAC_STAT(tx_jabber_irq),
@@ -86,7 +86,8 @@
STMMAC_STAT(rx_watchdog_irq),
STMMAC_STAT(tx_early_irq),
STMMAC_STAT(fatal_bus_error_irq),
- /* Extra info */
+ /* Tx/Rx IRQ Events */
+ STMMAC_STAT(rx_early_irq),
STMMAC_STAT(threshold),
STMMAC_STAT(tx_pkt_n),
STMMAC_STAT(rx_pkt_n),
@@ -96,10 +97,12 @@
STMMAC_STAT(tx_normal_irq_n),
STMMAC_STAT(tx_clean),
STMMAC_STAT(tx_reset_ic_bit),
+ STMMAC_STAT(irq_receive_pmt_irq_n),
+ /* MMC info */
STMMAC_STAT(mmc_tx_irq_n),
STMMAC_STAT(mmc_rx_irq_n),
STMMAC_STAT(mmc_rx_csum_offload_irq_n),
- STMMAC_STAT(irq_receive_pmt_irq_n),
+ /* EEE */
STMMAC_STAT(irq_tx_path_in_lpi_mode_n),
STMMAC_STAT(irq_tx_path_exit_lpi_mode_n),
STMMAC_STAT(irq_rx_path_in_lpi_mode_n),
diff --git a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
index d9d6864..542edbc 100644
--- a/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
+++ b/drivers/net/ethernet/stmicro/stmmac/stmmac_main.c
@@ -603,6 +603,8 @@
priv->dirty_tx = 0;
priv->cur_tx = 0;
+ if (priv->use_riwt)
+ dis_ic = 1;
/* Clear the Rx/Tx descriptors */
priv->hw->desc->init_rx_desc(priv->dma_rx, rxsize, dis_ic);
priv->hw->desc->init_tx_desc(priv->dma_tx, txsize);
@@ -1106,6 +1108,11 @@
stmmac_init_tx_coalesce(priv);
+ if ((priv->use_riwt) && (priv->hw->dma->rx_watchdog)) {
+ priv->rx_riwt = MAX_DMA_RIWT;
+ priv->hw->dma->rx_watchdog(priv->ioaddr, MAX_DMA_RIWT);
+ }
+
napi_enable(&priv->napi);
netif_start_queue(dev);
@@ -1423,14 +1430,12 @@
#endif
skb->protocol = eth_type_trans(skb, priv->dev);
- if (unlikely(!priv->plat->rx_coe)) {
- /* No RX COE for old mac10/100 devices */
+ if (unlikely(!priv->plat->rx_coe))
skb_checksum_none_assert(skb);
- netif_receive_skb(skb);
- } else {
+ else
skb->ip_summed = CHECKSUM_UNNECESSARY;
- napi_gro_receive(&priv->napi, skb);
- }
+
+ napi_gro_receive(&priv->napi, skb);
priv->dev->stats.rx_packets++;
priv->dev->stats.rx_bytes += frame_len;
@@ -2001,6 +2006,16 @@
if (flow_ctrl)
priv->flow_ctrl = FLOW_AUTO; /* RX/TX pause on */
+ /* Rx Watchdog is available in the COREs newer than the 3.40.
+ * In some case, for example on bugged HW this feature
+ * has to be disable and this can be done by passing the
+ * riwt_off field from the platform.
+ */
+ if ((priv->synopsys_id >= DWMAC_CORE_3_50) && (!priv->plat->riwt_off)) {
+ priv->use_riwt = 1;
+ pr_info(" Enable RX Mitigation via HW Watchdog Timer\n");
+ }
+
netif_napi_add(ndev, &priv->napi, stmmac_poll, 64);
spin_lock_init(&priv->lock);
@@ -2092,6 +2107,9 @@
netif_device_detach(ndev);
netif_stop_queue(ndev);
+ if (priv->use_riwt)
+ dis_ic = 1;
+
napi_disable(&priv->napi);
/* Stop TX/RX DMA */
diff --git a/include/linux/stmmac.h b/include/linux/stmmac.h
index a1547ea..de5b2f8 100644
--- a/include/linux/stmmac.h
+++ b/include/linux/stmmac.h
@@ -104,6 +104,7 @@
int bugged_jumbo;
int pmt;
int force_sf_dma_mode;
+ int riwt_off;
void (*fix_mac_speed)(void *priv, unsigned int speed);
void (*bus_setup)(void __iomem *ioaddr);
int (*init)(struct platform_device *pdev);