stmmac: prefetch all dma_erx when use extend_desc
[cascardo/linux.git] / drivers / net / ethernet / stmicro / stmmac / stmmac_main.c
index 39c6c55..71b6485 100644 (file)
@@ -46,7 +46,9 @@
 #ifdef CONFIG_STMMAC_DEBUG_FS
 #include <linux/debugfs.h>
 #include <linux/seq_file.h>
-#endif
+#endif /* CONFIG_STMMAC_DEBUG_FS */
+#include <linux/net_tstamp.h>
+#include "stmmac_ptp.h"
 #include "stmmac.h"
 
 #undef STMMAC_DEBUG
 #define JUMBO_LEN      9000
 
 /* Module parameters */
-#define TX_TIMEO 5000 /* default 5 seconds */
+#define TX_TIMEO       5000
 static int watchdog = TX_TIMEO;
 module_param(watchdog, int, S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(watchdog, "Transmit timeout in milliseconds");
+MODULE_PARM_DESC(watchdog, "Transmit timeout in milliseconds (default 5s)");
 
-static int debug = -1;         /* -1: default, 0: no output, 16:  all */
+static int debug = -1;
 module_param(debug, int, S_IRUGO | S_IWUSR);
-MODULE_PARM_DESC(debug, "Message Level (0: no output, 16: all)");
+MODULE_PARM_DESC(debug, "Message Level (-1: default, 0: no output, 16: all)");
 
 int phyaddr = -1;
 module_param(phyaddr, int, S_IRUGO);
@@ -130,6 +132,13 @@ module_param(eee_timer, int, S_IRUGO | S_IWUSR);
 MODULE_PARM_DESC(eee_timer, "LPI tx expiration time in msec");
 #define STMMAC_LPI_TIMER(x) (jiffies + msecs_to_jiffies(x))
 
+/* By default the driver will use the ring mode to manage tx and rx descriptors
+ * but passing this value so user can force to use the chain instead of the ring
+ */
+static unsigned int chain_mode;
+module_param(chain_mode, int, S_IRUGO);
+MODULE_PARM_DESC(chain_mode, "To use chain instead of ring mode");
+
 static irqreturn_t stmmac_interrupt(int irq, void *dev_id);
 
 #ifdef CONFIG_STMMAC_DEBUG_FS
@@ -164,6 +173,18 @@ static void stmmac_verify_args(void)
                eee_timer = STMMAC_DEFAULT_LPI_TIMER;
 }
 
+/**
+ * stmmac_clk_csr_set - dynamically set the MDC clock
+ * @priv: driver private structure
+ * Description: this is to dynamically set the MDC clock according to the csr
+ * clock input.
+ * Note:
+ *     If a specific clk_csr value is passed from the platform
+ *     this means that the CSR Clock Range selection cannot be
+ *     changed at run-time and it is fixed (as reported in the driver
+ *     documentation). Viceversa the driver will try to set the MDC
+ *     clock dynamically according to the actual clock input.
+ */
 static void stmmac_clk_csr_set(struct stmmac_priv *priv)
 {
        u32 clk_rate;
@@ -171,7 +192,12 @@ static void stmmac_clk_csr_set(struct stmmac_priv *priv)
        clk_rate = clk_get_rate(priv->stmmac_clk);
 
        /* Platform provided default clk_csr would be assumed valid
-        * for all other cases except for the below mentioned ones. */
+        * for all other cases except for the below mentioned ones.
+        * For values higher than the IEEE 802.3 specified frequency
+        * we can not estimate the proper divider as it is not known
+        * the frequency of clk_csr_i. So we do not change the default
+        * divider.
+        */
        if (!(priv->clk_csr & MAC_CSR_H_FRQ_MASK)) {
                if (clk_rate < CSR_F_35M)
                        priv->clk_csr = STMMAC_CSR_20_35M;
@@ -185,10 +211,7 @@ static void stmmac_clk_csr_set(struct stmmac_priv *priv)
                        priv->clk_csr = STMMAC_CSR_150_250M;
                else if ((clk_rate >= CSR_F_250M) && (clk_rate < CSR_F_300M))
                        priv->clk_csr = STMMAC_CSR_250_300M;
-       } /* For values higher than the IEEE 802.3 specified frequency
-          * we can not estimate the proper divider as it is not known
-          * the frequency of clk_csr_i. So we do not change the default
-          * divider. */
+       }
 }
 
 #if defined(STMMAC_XMIT_DEBUG) || defined(STMMAC_RX_DEBUG)
@@ -213,18 +236,25 @@ static inline u32 stmmac_tx_avail(struct stmmac_priv *priv)
        return priv->dirty_tx + priv->dma_tx_size - priv->cur_tx - 1;
 }
 
-/* On some ST platforms, some HW system configuraton registers have to be
- * set according to the link speed negotiated.
+/**
+ * stmmac_hw_fix_mac_speed: callback for speed selection
+ * @priv: driver private structure
+ * Description: on some platforms (e.g. ST), some HW system configuraton
+ * registers have to be set according to the link speed negotiated.
  */
 static inline void stmmac_hw_fix_mac_speed(struct stmmac_priv *priv)
 {
        struct phy_device *phydev = priv->phydev;
 
        if (likely(priv->plat->fix_mac_speed))
-               priv->plat->fix_mac_speed(priv->plat->bsp_priv,
-                                         phydev->speed);
+               priv->plat->fix_mac_speed(priv->plat->bsp_priv, phydev->speed);
 }
 
+/**
+ * stmmac_enable_eee_mode: Check and enter in LPI mode
+ * @priv: driver private structure
+ * Description: this function is to verify and enter in LPI mode for EEE.
+ */
 static void stmmac_enable_eee_mode(struct stmmac_priv *priv)
 {
        /* Check and enter in LPI mode */
@@ -233,19 +263,24 @@ static void stmmac_enable_eee_mode(struct stmmac_priv *priv)
                priv->hw->mac->set_eee_mode(priv->ioaddr);
 }
 
+/**
+ * stmmac_disable_eee_mode: disable/exit from EEE
+ * @priv: driver private structure
+ * Description: this function is to exit and disable EEE in case of
+ * LPI state is true. This is called by the xmit.
+ */
 void stmmac_disable_eee_mode(struct stmmac_priv *priv)
 {
-       /* Exit and disable EEE in case of we are are in LPI state. */
        priv->hw->mac->reset_eee_mode(priv->ioaddr);
        del_timer_sync(&priv->eee_ctrl_timer);
        priv->tx_path_in_lpi_mode = false;
 }
 
 /**
- * stmmac_eee_ctrl_timer
+ * stmmac_eee_ctrl_timer: EEE TX SW timer.
  * @arg : data hook
  * Description:
- *  If there is no data transfer and if we are not in LPI state,
+ *  if there is no data transfer and if we are not in LPI state,
  *  then MAC Transmitter can be moved to LPI state.
  */
 static void stmmac_eee_ctrl_timer(unsigned long arg)
@@ -257,8 +292,8 @@ static void stmmac_eee_ctrl_timer(unsigned long arg)
 }
 
 /**
- * stmmac_eee_init
- * @priv: private device pointer
+ * stmmac_eee_init: init EEE
+ * @priv: driver private structure
  * Description:
  *  If the EEE support has been enabled while configuring the driver,
  *  if the GMAC actually supports the EEE (from the HW cap reg) and the
@@ -294,16 +329,359 @@ out:
        return ret;
 }
 
+/**
+ * stmmac_eee_adjust: adjust HW EEE according to the speed
+ * @priv: driver private structure
+ * Description:
+ *     When the EEE has been already initialised we have to
+ *     modify the PLS bit in the LPI ctrl & status reg according
+ *     to the PHY link status. For this reason.
+ */
 static void stmmac_eee_adjust(struct stmmac_priv *priv)
 {
-       /* When the EEE has been already initialised we have to
-        * modify the PLS bit in the LPI ctrl & status reg according
-        * to the PHY link status. For this reason.
-        */
        if (priv->eee_enabled)
                priv->hw->mac->set_eee_pls(priv->ioaddr, priv->phydev->link);
 }
 
+/* stmmac_get_tx_hwtstamp: get HW TX timestamps
+ * @priv: driver private structure
+ * @entry : descriptor index to be used.
+ * @skb : the socket buffer
+ * Description :
+ * This function will read timestamp from the descriptor & pass it to stack.
+ * and also perform some sanity checks.
+ */
+static void stmmac_get_tx_hwtstamp(struct stmmac_priv *priv,
+                                  unsigned int entry, struct sk_buff *skb)
+{
+       struct skb_shared_hwtstamps shhwtstamp;
+       u64 ns;
+       void *desc = NULL;
+
+       if (!priv->hwts_tx_en)
+               return;
+
+       /* exit if skb doesn't support hw tstamp */
+       if (likely(!(skb_shinfo(skb)->tx_flags & SKBTX_IN_PROGRESS)))
+               return;
+
+       if (priv->adv_ts)
+               desc = (priv->dma_etx + entry);
+       else
+               desc = (priv->dma_tx + entry);
+
+       /* check tx tstamp status */
+       if (!priv->hw->desc->get_tx_timestamp_status((struct dma_desc *)desc))
+               return;
+
+       /* get the valid tstamp */
+       ns = priv->hw->desc->get_timestamp(desc, priv->adv_ts);
+
+       memset(&shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));
+       shhwtstamp.hwtstamp = ns_to_ktime(ns);
+       /* pass tstamp to stack */
+       skb_tstamp_tx(skb, &shhwtstamp);
+
+       return;
+}
+
+/* stmmac_get_rx_hwtstamp: get HW RX timestamps
+ * @priv: driver private structure
+ * @entry : descriptor index to be used.
+ * @skb : the socket buffer
+ * Description :
+ * This function will read received packet's timestamp from the descriptor
+ * and pass it to stack. It also perform some sanity checks.
+ */
+static void stmmac_get_rx_hwtstamp(struct stmmac_priv *priv,
+                                  unsigned int entry, struct sk_buff *skb)
+{
+       struct skb_shared_hwtstamps *shhwtstamp = NULL;
+       u64 ns;
+       void *desc = NULL;
+
+       if (!priv->hwts_rx_en)
+               return;
+
+       if (priv->adv_ts)
+               desc = (priv->dma_erx + entry);
+       else
+               desc = (priv->dma_rx + entry);
+
+       /* exit if rx tstamp is not valid */
+       if (!priv->hw->desc->get_rx_timestamp_status(desc, priv->adv_ts))
+               return;
+
+       /* get valid tstamp */
+       ns = priv->hw->desc->get_timestamp(desc, priv->adv_ts);
+       shhwtstamp = skb_hwtstamps(skb);
+       memset(shhwtstamp, 0, sizeof(struct skb_shared_hwtstamps));
+       shhwtstamp->hwtstamp = ns_to_ktime(ns);
+}
+
+/**
+ *  stmmac_hwtstamp_ioctl - control hardware timestamping.
+ *  @dev: device pointer.
+ *  @ifr: An IOCTL specefic structure, that can contain a pointer to
+ *  a proprietary structure used to pass information to the driver.
+ *  Description:
+ *  This function configures the MAC to enable/disable both outgoing(TX)
+ *  and incoming(RX) packets time stamping based on user input.
+ *  Return Value:
+ *  0 on success and an appropriate -ve integer on failure.
+ */
+static int stmmac_hwtstamp_ioctl(struct net_device *dev, struct ifreq *ifr)
+{
+       struct stmmac_priv *priv = netdev_priv(dev);
+       struct hwtstamp_config config;
+       struct timespec now;
+       u64 temp = 0;
+       u32 ptp_v2 = 0;
+       u32 tstamp_all = 0;
+       u32 ptp_over_ipv4_udp = 0;
+       u32 ptp_over_ipv6_udp = 0;
+       u32 ptp_over_ethernet = 0;
+       u32 snap_type_sel = 0;
+       u32 ts_master_en = 0;
+       u32 ts_event_en = 0;
+       u32 value = 0;
+
+       if (!(priv->dma_cap.time_stamp || priv->adv_ts)) {
+               netdev_alert(priv->dev, "No support for HW time stamping\n");
+               priv->hwts_tx_en = 0;
+               priv->hwts_rx_en = 0;
+
+               return -EOPNOTSUPP;
+       }
+
+       if (copy_from_user(&config, ifr->ifr_data,
+                          sizeof(struct hwtstamp_config)))
+               return -EFAULT;
+
+       pr_debug("%s config flags:0x%x, tx_type:0x%x, rx_filter:0x%x\n",
+                __func__, config.flags, config.tx_type, config.rx_filter);
+
+       /* reserved for future extensions */
+       if (config.flags)
+               return -EINVAL;
+
+       switch (config.tx_type) {
+       case HWTSTAMP_TX_OFF:
+               priv->hwts_tx_en = 0;
+               break;
+       case HWTSTAMP_TX_ON:
+               priv->hwts_tx_en = 1;
+               break;
+       default:
+               return -ERANGE;
+       }
+
+       if (priv->adv_ts) {
+               switch (config.rx_filter) {
+               case HWTSTAMP_FILTER_NONE:
+                       /* time stamp no incoming packet at all */
+                       config.rx_filter = HWTSTAMP_FILTER_NONE;
+                       break;
+
+               case HWTSTAMP_FILTER_PTP_V1_L4_EVENT:
+                       /* PTP v1, UDP, any kind of event packet */
+                       config.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_EVENT;
+                       /* take time stamp for all event messages */
+                       snap_type_sel = PTP_TCR_SNAPTYPSEL_1;
+
+                       ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
+                       ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
+                       break;
+
+               case HWTSTAMP_FILTER_PTP_V1_L4_SYNC:
+                       /* PTP v1, UDP, Sync packet */
+                       config.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_SYNC;
+                       /* take time stamp for SYNC messages only */
+                       ts_event_en = PTP_TCR_TSEVNTENA;
+
+                       ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
+                       ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
+                       break;
+
+               case HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ:
+                       /* PTP v1, UDP, Delay_req packet */
+                       config.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_DELAY_REQ;
+                       /* take time stamp for Delay_Req messages only */
+                       ts_master_en = PTP_TCR_TSMSTRENA;
+                       ts_event_en = PTP_TCR_TSEVNTENA;
+
+                       ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
+                       ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
+                       break;
+
+               case HWTSTAMP_FILTER_PTP_V2_L4_EVENT:
+                       /* PTP v2, UDP, any kind of event packet */
+                       config.rx_filter = HWTSTAMP_FILTER_PTP_V2_L4_EVENT;
+                       ptp_v2 = PTP_TCR_TSVER2ENA;
+                       /* take time stamp for all event messages */
+                       snap_type_sel = PTP_TCR_SNAPTYPSEL_1;
+
+                       ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
+                       ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
+                       break;
+
+               case HWTSTAMP_FILTER_PTP_V2_L4_SYNC:
+                       /* PTP v2, UDP, Sync packet */
+                       config.rx_filter = HWTSTAMP_FILTER_PTP_V2_L4_SYNC;
+                       ptp_v2 = PTP_TCR_TSVER2ENA;
+                       /* take time stamp for SYNC messages only */
+                       ts_event_en = PTP_TCR_TSEVNTENA;
+
+                       ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
+                       ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
+                       break;
+
+               case HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ:
+                       /* PTP v2, UDP, Delay_req packet */
+                       config.rx_filter = HWTSTAMP_FILTER_PTP_V2_L4_DELAY_REQ;
+                       ptp_v2 = PTP_TCR_TSVER2ENA;
+                       /* take time stamp for Delay_Req messages only */
+                       ts_master_en = PTP_TCR_TSMSTRENA;
+                       ts_event_en = PTP_TCR_TSEVNTENA;
+
+                       ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
+                       ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
+                       break;
+
+               case HWTSTAMP_FILTER_PTP_V2_EVENT:
+                       /* PTP v2/802.AS1 any layer, any kind of event packet */
+                       config.rx_filter = HWTSTAMP_FILTER_PTP_V2_EVENT;
+                       ptp_v2 = PTP_TCR_TSVER2ENA;
+                       /* take time stamp for all event messages */
+                       snap_type_sel = PTP_TCR_SNAPTYPSEL_1;
+
+                       ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
+                       ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
+                       ptp_over_ethernet = PTP_TCR_TSIPENA;
+                       break;
+
+               case HWTSTAMP_FILTER_PTP_V2_SYNC:
+                       /* PTP v2/802.AS1, any layer, Sync packet */
+                       config.rx_filter = HWTSTAMP_FILTER_PTP_V2_SYNC;
+                       ptp_v2 = PTP_TCR_TSVER2ENA;
+                       /* take time stamp for SYNC messages only */
+                       ts_event_en = PTP_TCR_TSEVNTENA;
+
+                       ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
+                       ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
+                       ptp_over_ethernet = PTP_TCR_TSIPENA;
+                       break;
+
+               case HWTSTAMP_FILTER_PTP_V2_DELAY_REQ:
+                       /* PTP v2/802.AS1, any layer, Delay_req packet */
+                       config.rx_filter = HWTSTAMP_FILTER_PTP_V2_DELAY_REQ;
+                       ptp_v2 = PTP_TCR_TSVER2ENA;
+                       /* take time stamp for Delay_Req messages only */
+                       ts_master_en = PTP_TCR_TSMSTRENA;
+                       ts_event_en = PTP_TCR_TSEVNTENA;
+
+                       ptp_over_ipv4_udp = PTP_TCR_TSIPV4ENA;
+                       ptp_over_ipv6_udp = PTP_TCR_TSIPV6ENA;
+                       ptp_over_ethernet = PTP_TCR_TSIPENA;
+                       break;
+
+               case HWTSTAMP_FILTER_ALL:
+                       /* time stamp any incoming packet */
+                       config.rx_filter = HWTSTAMP_FILTER_ALL;
+                       tstamp_all = PTP_TCR_TSENALL;
+                       break;
+
+               default:
+                       return -ERANGE;
+               }
+       } else {
+               switch (config.rx_filter) {
+               case HWTSTAMP_FILTER_NONE:
+                       config.rx_filter = HWTSTAMP_FILTER_NONE;
+                       break;
+               default:
+                       /* PTP v1, UDP, any kind of event packet */
+                       config.rx_filter = HWTSTAMP_FILTER_PTP_V1_L4_EVENT;
+                       break;
+               }
+       }
+       priv->hwts_rx_en = ((config.rx_filter == HWTSTAMP_FILTER_NONE) ? 0 : 1);
+
+       if (!priv->hwts_tx_en && !priv->hwts_rx_en)
+               priv->hw->ptp->config_hw_tstamping(priv->ioaddr, 0);
+       else {
+               value = (PTP_TCR_TSENA | PTP_TCR_TSCFUPDT | PTP_TCR_TSCTRLSSR |
+                        tstamp_all | ptp_v2 | ptp_over_ethernet |
+                        ptp_over_ipv6_udp | ptp_over_ipv4_udp | ts_event_en |
+                        ts_master_en | snap_type_sel);
+
+               priv->hw->ptp->config_hw_tstamping(priv->ioaddr, value);
+
+               /* program Sub Second Increment reg */
+               priv->hw->ptp->config_sub_second_increment(priv->ioaddr);
+
+               /* calculate default added value:
+                * formula is :
+                * addend = (2^32)/freq_div_ratio;
+                * where, freq_div_ratio = STMMAC_SYSCLOCK/50MHz
+                * hence, addend = ((2^32) * 50MHz)/STMMAC_SYSCLOCK;
+                * NOTE: STMMAC_SYSCLOCK should be >= 50MHz to
+                *       achive 20ns accuracy.
+                *
+                * 2^x * y == (y << x), hence
+                * 2^32 * 50000000 ==> (50000000 << 32)
+                */
+               temp = (u64) (50000000ULL << 32);
+               priv->default_addend = div_u64(temp, STMMAC_SYSCLOCK);
+               priv->hw->ptp->config_addend(priv->ioaddr,
+                                            priv->default_addend);
+
+               /* initialize system time */
+               getnstimeofday(&now);
+               priv->hw->ptp->init_systime(priv->ioaddr, now.tv_sec,
+                                           now.tv_nsec);
+       }
+
+       return copy_to_user(ifr->ifr_data, &config,
+                           sizeof(struct hwtstamp_config)) ? -EFAULT : 0;
+}
+
+/**
+ * stmmac_init_ptp: init PTP
+ * @priv: driver private structure
+ * Description: this is to verify if the HW supports the PTPv1 or v2.
+ * This is done by looking at the HW cap. register.
+ * Also it registers the ptp driver.
+ */
+static int stmmac_init_ptp(struct stmmac_priv *priv)
+{
+       if (!(priv->dma_cap.time_stamp || priv->dma_cap.atime_stamp))
+               return -EOPNOTSUPP;
+
+       if (netif_msg_hw(priv)) {
+               if (priv->dma_cap.time_stamp) {
+                       pr_debug("IEEE 1588-2002 Time Stamp supported\n");
+                       priv->adv_ts = 0;
+               }
+               if (priv->dma_cap.atime_stamp && priv->extend_desc) {
+                       pr_debug
+                           ("IEEE 1588-2008 Advanced Time Stamp supported\n");
+                       priv->adv_ts = 1;
+               }
+       }
+
+       priv->hw->ptp = &stmmac_ptp;
+       priv->hwts_tx_en = 0;
+       priv->hwts_rx_en = 0;
+
+       return stmmac_ptp_register(priv);
+}
+
+static void stmmac_release_ptp(struct stmmac_priv *priv)
+{
+       stmmac_ptp_unregister(priv);
+}
+
 /**
  * stmmac_adjust_link
  * @dev: net device structure
@@ -349,7 +727,7 @@ static void stmmac_adjust_link(struct net_device *dev)
                        case 1000:
                                if (likely(priv->plat->has_gmac))
                                        ctrl &= ~priv->hw->link.port;
-                                       stmmac_hw_fix_mac_speed(priv);
+                               stmmac_hw_fix_mac_speed(priv);
                                break;
                        case 100:
                        case 10:
@@ -367,8 +745,8 @@ static void stmmac_adjust_link(struct net_device *dev)
                                break;
                        default:
                                if (netif_msg_link(priv))
-                                       pr_warning("%s: Speed (%d) is not 10"
-                                      " or 100!\n", dev->name, phydev->speed);
+                                       pr_warn("%s: Speed (%d) not 10/100\n",
+                                               dev->name, phydev->speed);
                                break;
                        }
 
@@ -398,6 +776,31 @@ static void stmmac_adjust_link(struct net_device *dev)
        DBG(probe, DEBUG, "stmmac_adjust_link: exiting\n");
 }
 
+/**
+ * stmmac_check_pcs_mode: verify if RGMII/SGMII is supported
+ * @priv: driver private structure
+ * Description: this is to verify if the HW supports the PCS.
+ * Physical Coding Sublayer (PCS) interface that can be used when the MAC is
+ * configured for the TBI, RTBI, or SGMII PHY interface.
+ */
+static void stmmac_check_pcs_mode(struct stmmac_priv *priv)
+{
+       int interface = priv->plat->interface;
+
+       if (priv->dma_cap.pcs) {
+               if ((interface & PHY_INTERFACE_MODE_RGMII) ||
+                   (interface & PHY_INTERFACE_MODE_RGMII_ID) ||
+                   (interface & PHY_INTERFACE_MODE_RGMII_RXID) ||
+                   (interface & PHY_INTERFACE_MODE_RGMII_TXID)) {
+                       pr_debug("STMMAC: PCS RGMII support enable\n");
+                       priv->pcs = STMMAC_PCS_RGMII;
+               } else if (interface & PHY_INTERFACE_MODE_SGMII) {
+                       pr_debug("STMMAC: PCS SGMII support enable\n");
+                       priv->pcs = STMMAC_PCS_SGMII;
+               }
+       }
+}
+
 /**
  * stmmac_init_phy - PHY initialization
  * @dev: net device structure
@@ -419,10 +822,10 @@ static int stmmac_init_phy(struct net_device *dev)
 
        if (priv->plat->phy_bus_name)
                snprintf(bus_id, MII_BUS_ID_SIZE, "%s-%x",
-                               priv->plat->phy_bus_name, priv->plat->bus_id);
+                        priv->plat->phy_bus_name, priv->plat->bus_id);
        else
                snprintf(bus_id, MII_BUS_ID_SIZE, "stmmac-%x",
-                               priv->plat->bus_id);
+                        priv->plat->bus_id);
 
        snprintf(phy_id_fmt, MII_BUS_ID_SIZE + 3, PHY_ID_FMT, bus_id,
                 priv->plat->phy_addr);
@@ -461,29 +864,57 @@ static int stmmac_init_phy(struct net_device *dev)
 }
 
 /**
- * display_ring
- * @p: pointer to the ring.
+ * stmmac_display_ring: display ring
+ * @head: pointer to the head of the ring passed.
  * @size: size of the ring.
- * Description: display all the descriptors within the ring.
+ * @extend_desc: to verify if extended descriptors are used.
+ * Description: display the control/status and buffer descriptors.
  */
-static void display_ring(struct dma_desc *p, int size)
+static void stmmac_display_ring(void *head, int size, int extend_desc)
 {
-       struct tmp_s {
-               u64 a;
-               unsigned int b;
-               unsigned int c;
-       };
        int i;
+       struct dma_extended_desc *ep = (struct dma_extended_desc *)head;
+       struct dma_desc *p = (struct dma_desc *)head;
+
        for (i = 0; i < size; i++) {
-               struct tmp_s *x = (struct tmp_s *)(p + i);
-               pr_info("\t%d [0x%x]: DES0=0x%x DES1=0x%x BUF1=0x%x BUF2=0x%x",
-                      i, (unsigned int)virt_to_phys(&p[i]),
-                      (unsigned int)(x->a), (unsigned int)((x->a) >> 32),
-                      x->b, x->c);
+               u64 x;
+               if (extend_desc) {
+                       x = *(u64 *) ep;
+                       pr_info("%d [0x%x]: 0x%x 0x%x 0x%x 0x%x\n",
+                               i, (unsigned int)virt_to_phys(ep),
+                               (unsigned int)x, (unsigned int)(x >> 32),
+                               ep->basic.des2, ep->basic.des3);
+                       ep++;
+               } else {
+                       x = *(u64 *) p;
+                       pr_info("%d [0x%x]: 0x%x 0x%x 0x%x 0x%x",
+                               i, (unsigned int)virt_to_phys(p),
+                               (unsigned int)x, (unsigned int)(x >> 32),
+                               p->des2, p->des3);
+                       p++;
+               }
                pr_info("\n");
        }
 }
 
+static void stmmac_display_rings(struct stmmac_priv *priv)
+{
+       unsigned int txsize = priv->dma_tx_size;
+       unsigned int rxsize = priv->dma_rx_size;
+
+       if (priv->extend_desc) {
+               pr_info("Extended RX descriptor ring:\n");
+               stmmac_display_ring((void *)priv->dma_erx, rxsize, 1);
+               pr_info("Extended TX descriptor ring:\n");
+               stmmac_display_ring((void *)priv->dma_etx, txsize, 1);
+       } else {
+               pr_info("RX descriptor ring:\n");
+               stmmac_display_ring((void *)priv->dma_rx, rxsize, 0);
+               pr_info("TX descriptor ring:\n");
+               stmmac_display_ring((void *)priv->dma_tx, txsize, 0);
+       }
+}
+
 static int stmmac_set_bfsize(int mtu, int bufsize)
 {
        int ret = bufsize;
@@ -500,6 +931,65 @@ static int stmmac_set_bfsize(int mtu, int bufsize)
        return ret;
 }
 
+/**
+ * stmmac_clear_descriptors: clear descriptors
+ * @priv: driver private structure
+ * Description: this function is called to clear the tx and rx descriptors
+ * in case of both basic and extended descriptors are used.
+ */
+static void stmmac_clear_descriptors(struct stmmac_priv *priv)
+{
+       int i;
+       unsigned int txsize = priv->dma_tx_size;
+       unsigned int rxsize = priv->dma_rx_size;
+
+       /* Clear the Rx/Tx descriptors */
+       for (i = 0; i < rxsize; i++)
+               if (priv->extend_desc)
+                       priv->hw->desc->init_rx_desc(&priv->dma_erx[i].basic,
+                                                    priv->use_riwt, priv->mode,
+                                                    (i == rxsize - 1));
+               else
+                       priv->hw->desc->init_rx_desc(&priv->dma_rx[i],
+                                                    priv->use_riwt, priv->mode,
+                                                    (i == rxsize - 1));
+       for (i = 0; i < txsize; i++)
+               if (priv->extend_desc)
+                       priv->hw->desc->init_tx_desc(&priv->dma_etx[i].basic,
+                                                    priv->mode,
+                                                    (i == txsize - 1));
+               else
+                       priv->hw->desc->init_tx_desc(&priv->dma_tx[i],
+                                                    priv->mode,
+                                                    (i == txsize - 1));
+}
+
+static int stmmac_init_rx_buffers(struct stmmac_priv *priv, struct dma_desc *p,
+                                 int i)
+{
+       struct sk_buff *skb;
+
+       skb = __netdev_alloc_skb(priv->dev, priv->dma_buf_sz + NET_IP_ALIGN,
+                                GFP_KERNEL);
+       if (unlikely(skb == NULL)) {
+               pr_err("%s: Rx init fails; skb is NULL\n", __func__);
+               return 1;
+       }
+       skb_reserve(skb, NET_IP_ALIGN);
+       priv->rx_skbuff[i] = skb;
+       priv->rx_skbuff_dma[i] = dma_map_single(priv->device, skb->data,
+                                               priv->dma_buf_sz,
+                                               DMA_FROM_DEVICE);
+
+       p->des2 = priv->rx_skbuff_dma[i];
+
+       if ((priv->mode == STMMAC_RING_MODE) &&
+           (priv->dma_buf_sz == BUF_SIZE_16KiB))
+               priv->hw->ring->init_desc3(p);
+
+       return 0;
+}
+
 /**
  * init_dma_desc_rings - init the RX/TX descriptor rings
  * @dev: net device structure
@@ -511,110 +1001,114 @@ static void init_dma_desc_rings(struct net_device *dev)
 {
        int i;
        struct stmmac_priv *priv = netdev_priv(dev);
-       struct sk_buff *skb;
        unsigned int txsize = priv->dma_tx_size;
        unsigned int rxsize = priv->dma_rx_size;
-       unsigned int bfsize;
-       int dis_ic = 0;
-       int des3_as_data_buf = 0;
+       unsigned int bfsize = 0;
 
        /* Set the max buffer size according to the DESC mode
-        * and the MTU. Note that RING mode allows 16KiB bsize. */
-       bfsize = priv->hw->ring->set_16kib_bfsize(dev->mtu);
+        * and the MTU. Note that RING mode allows 16KiB bsize.
+        */
+       if (priv->mode == STMMAC_RING_MODE)
+               bfsize = priv->hw->ring->set_16kib_bfsize(dev->mtu);
 
-       if (bfsize == BUF_SIZE_16KiB)
-               des3_as_data_buf = 1;
-       else
+       if (bfsize < BUF_SIZE_16KiB)
                bfsize = stmmac_set_bfsize(dev->mtu, priv->dma_buf_sz);
 
        DBG(probe, INFO, "stmmac: txsize %d, rxsize %d, bfsize %d\n",
            txsize, rxsize, bfsize);
 
-       priv->rx_skbuff_dma = kmalloc_array(rxsize, sizeof(dma_addr_t),
-                                           GFP_KERNEL);
-       priv->rx_skbuff = kmalloc_array(rxsize, sizeof(struct sk_buff *),
-                                       GFP_KERNEL);
-       priv->dma_rx =
-           (struct dma_desc *)dma_alloc_coherent(priv->device,
-                                                 rxsize *
+       if (priv->extend_desc) {
+               priv->dma_erx = dma_alloc_coherent(priv->device, rxsize *
+                                                  sizeof(struct
+                                                         dma_extended_desc),
+                                                  &priv->dma_rx_phy,
+                                                  GFP_KERNEL);
+               priv->dma_etx = dma_alloc_coherent(priv->device, txsize *
+                                                  sizeof(struct
+                                                         dma_extended_desc),
+                                                  &priv->dma_tx_phy,
+                                                  GFP_KERNEL);
+               if ((!priv->dma_erx) || (!priv->dma_etx))
+                       return;
+       } else {
+               priv->dma_rx = dma_alloc_coherent(priv->device, rxsize *
                                                  sizeof(struct dma_desc),
                                                  &priv->dma_rx_phy,
                                                  GFP_KERNEL);
-       priv->tx_skbuff = kmalloc_array(txsize, sizeof(struct sk_buff *),
-                                       GFP_KERNEL);
-       priv->dma_tx =
-           (struct dma_desc *)dma_alloc_coherent(priv->device,
-                                                 txsize *
+               priv->dma_tx = dma_alloc_coherent(priv->device, txsize *
                                                  sizeof(struct dma_desc),
                                                  &priv->dma_tx_phy,
                                                  GFP_KERNEL);
-
-       if ((priv->dma_rx == NULL) || (priv->dma_tx == NULL)) {
-               pr_err("%s:ERROR allocating the DMA Tx/Rx desc\n", __func__);
-               return;
+               if ((!priv->dma_rx) || (!priv->dma_tx))
+                       return;
        }
 
-       DBG(probe, INFO, "stmmac (%s) DMA desc: virt addr (Rx %p, "
-           "Tx %p)\n\tDMA phy addr (Rx 0x%08x, Tx 0x%08x)\n",
-           dev->name, priv->dma_rx, priv->dma_tx,
-           (unsigned int)priv->dma_rx_phy, (unsigned int)priv->dma_tx_phy);
+       priv->rx_skbuff_dma = kmalloc_array(rxsize, sizeof(dma_addr_t),
+                                           GFP_KERNEL);
+       priv->rx_skbuff = kmalloc_array(rxsize, sizeof(struct sk_buff *),
+                                       GFP_KERNEL);
+       priv->tx_skbuff_dma = kmalloc_array(txsize, sizeof(dma_addr_t),
+                                           GFP_KERNEL);
+       priv->tx_skbuff = kmalloc_array(txsize, sizeof(struct sk_buff *),
+                                       GFP_KERNEL);
+       if (netif_msg_drv(priv))
+               pr_debug("(%s) dma_rx_phy=0x%08x dma_tx_phy=0x%08x\n", __func__,
+                        (u32) priv->dma_rx_phy, (u32) priv->dma_tx_phy);
 
        /* RX INITIALIZATION */
-       DBG(probe, INFO, "stmmac: SKB addresses:\n"
-                        "skb\t\tskb data\tdma data\n");
-
+       DBG(probe, INFO, "stmmac: SKB addresses:\nskb\t\tskb data\tdma data\n");
        for (i = 0; i < rxsize; i++) {
-               struct dma_desc *p = priv->dma_rx + i;
+               struct dma_desc *p;
+               if (priv->extend_desc)
+                       p = &((priv->dma_erx + i)->basic);
+               else
+                       p = priv->dma_rx + i;
 
-               skb = __netdev_alloc_skb(dev, bfsize + NET_IP_ALIGN,
-                                        GFP_KERNEL);
-               if (unlikely(skb == NULL)) {
-                       pr_err("%s: Rx init fails; skb is NULL\n", __func__);
+               if (stmmac_init_rx_buffers(priv, p, i))
                        break;
-               }
-               skb_reserve(skb, NET_IP_ALIGN);
-               priv->rx_skbuff[i] = skb;
-               priv->rx_skbuff_dma[i] = dma_map_single(priv->device, skb->data,
-                                               bfsize, DMA_FROM_DEVICE);
-
-               p->des2 = priv->rx_skbuff_dma[i];
-
-               priv->hw->ring->init_desc3(des3_as_data_buf, p);
 
                DBG(probe, INFO, "[%p]\t[%p]\t[%x]\n", priv->rx_skbuff[i],
-                       priv->rx_skbuff[i]->data, priv->rx_skbuff_dma[i]);
+                   priv->rx_skbuff[i]->data, priv->rx_skbuff_dma[i]);
        }
        priv->cur_rx = 0;
        priv->dirty_rx = (unsigned int)(i - rxsize);
        priv->dma_buf_sz = bfsize;
        buf_sz = bfsize;
 
+       /* Setup the chained descriptor addresses */
+       if (priv->mode == STMMAC_CHAIN_MODE) {
+               if (priv->extend_desc) {
+                       priv->hw->chain->init(priv->dma_erx, priv->dma_rx_phy,
+                                             rxsize, 1);
+                       priv->hw->chain->init(priv->dma_etx, priv->dma_tx_phy,
+                                             txsize, 1);
+               } else {
+                       priv->hw->chain->init(priv->dma_rx, priv->dma_rx_phy,
+                                             rxsize, 0);
+                       priv->hw->chain->init(priv->dma_tx, priv->dma_tx_phy,
+                                             txsize, 0);
+               }
+       }
+
        /* TX INITIALIZATION */
        for (i = 0; i < txsize; i++) {
+               struct dma_desc *p;
+               if (priv->extend_desc)
+                       p = &((priv->dma_etx + i)->basic);
+               else
+                       p = priv->dma_tx + i;
+               p->des2 = 0;
+               priv->tx_skbuff_dma[i] = 0;
                priv->tx_skbuff[i] = NULL;
-               priv->dma_tx[i].des2 = 0;
        }
 
-       /* In case of Chained mode this sets the des3 to the next
-        * element in the chain */
-       priv->hw->ring->init_dma_chain(priv->dma_rx, priv->dma_rx_phy, rxsize);
-       priv->hw->ring->init_dma_chain(priv->dma_tx, priv->dma_tx_phy, txsize);
-
        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);
+       stmmac_clear_descriptors(priv);
 
-       if (netif_msg_hw(priv)) {
-               pr_info("RX descriptor ring:\n");
-               display_ring(priv->dma_rx, rxsize);
-               pr_info("TX descriptor ring:\n");
-               display_ring(priv->dma_tx, txsize);
-       }
+       if (netif_msg_hw(priv))
+               stmmac_display_rings(priv);
 }
 
 static void dma_free_rx_skbufs(struct stmmac_priv *priv)
@@ -637,13 +1131,20 @@ static void dma_free_tx_skbufs(struct stmmac_priv *priv)
 
        for (i = 0; i < priv->dma_tx_size; i++) {
                if (priv->tx_skbuff[i] != NULL) {
-                       struct dma_desc *p = priv->dma_tx + i;
-                       if (p->des2)
-                               dma_unmap_single(priv->device, p->des2,
+                       struct dma_desc *p;
+                       if (priv->extend_desc)
+                               p = &((priv->dma_etx + i)->basic);
+                       else
+                               p = priv->dma_tx + i;
+
+                       if (priv->tx_skbuff_dma[i])
+                               dma_unmap_single(priv->device,
+                                                priv->tx_skbuff_dma[i],
                                                 priv->hw->desc->get_tx_len(p),
                                                 DMA_TO_DEVICE);
                        dev_kfree_skb_any(priv->tx_skbuff[i]);
                        priv->tx_skbuff[i] = NULL;
+                       priv->tx_skbuff_dma[i] = 0;
                }
        }
 }
@@ -654,29 +1155,38 @@ static void free_dma_desc_resources(struct stmmac_priv *priv)
        dma_free_rx_skbufs(priv);
        dma_free_tx_skbufs(priv);
 
-       /* Free the region of consistent memory previously allocated for
-        * the DMA */
-       dma_free_coherent(priv->device,
-                         priv->dma_tx_size * sizeof(struct dma_desc),
-                         priv->dma_tx, priv->dma_tx_phy);
-       dma_free_coherent(priv->device,
-                         priv->dma_rx_size * sizeof(struct dma_desc),
-                         priv->dma_rx, priv->dma_rx_phy);
+       /* Free DMA regions of consistent memory previously allocated */
+       if (!priv->extend_desc) {
+               dma_free_coherent(priv->device,
+                                 priv->dma_tx_size * sizeof(struct dma_desc),
+                                 priv->dma_tx, priv->dma_tx_phy);
+               dma_free_coherent(priv->device,
+                                 priv->dma_rx_size * sizeof(struct dma_desc),
+                                 priv->dma_rx, priv->dma_rx_phy);
+       } else {
+               dma_free_coherent(priv->device, priv->dma_tx_size *
+                                 sizeof(struct dma_extended_desc),
+                                 priv->dma_etx, priv->dma_tx_phy);
+               dma_free_coherent(priv->device, priv->dma_rx_size *
+                                 sizeof(struct dma_extended_desc),
+                                 priv->dma_erx, priv->dma_rx_phy);
+       }
        kfree(priv->rx_skbuff_dma);
        kfree(priv->rx_skbuff);
+       kfree(priv->tx_skbuff_dma);
        kfree(priv->tx_skbuff);
 }
 
 /**
  *  stmmac_dma_operation_mode - HW DMA operation mode
- *  @priv : pointer to the private device structure.
+ *  @priv: driver private structure
  *  Description: it sets the DMA operation mode: tx/rx DMA thresholds
  *  or Store-And-Forward capability.
  */
 static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
 {
        if (likely(priv->plat->force_sf_dma_mode ||
-               ((priv->plat->tx_coe) && (!priv->no_csum_insertion)))) {
+                  ((priv->plat->tx_coe) && (!priv->no_csum_insertion)))) {
                /*
                 * In case of GMAC, SF mode can be enabled
                 * to perform the TX COE in HW. This depends on:
@@ -684,8 +1194,7 @@ static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
                 * 2) There is no bugged Jumbo frame support
                 *    that needs to not insert csum in the TDES.
                 */
-               priv->hw->dma->dma_mode(priv->ioaddr,
-                                       SF_DMA_MODE, SF_DMA_MODE);
+               priv->hw->dma->dma_mode(priv->ioaddr, SF_DMA_MODE, SF_DMA_MODE);
                tc = SF_DMA_MODE;
        } else
                priv->hw->dma->dma_mode(priv->ioaddr, tc, SF_DMA_MODE);
@@ -693,7 +1202,7 @@ static void stmmac_dma_operation_mode(struct stmmac_priv *priv)
 
 /**
  * stmmac_tx_clean:
- * @priv: private data pointer
+ * @priv: driver private structure
  * Description: it reclaims resources after transmission completes.
  */
 static void stmmac_tx_clean(struct stmmac_priv *priv)
@@ -708,40 +1217,50 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
                int last;
                unsigned int entry = priv->dirty_tx % txsize;
                struct sk_buff *skb = priv->tx_skbuff[entry];
-               struct dma_desc *p = priv->dma_tx + entry;
+               struct dma_desc *p;
+
+               if (priv->extend_desc)
+                       p = (struct dma_desc *)(priv->dma_etx + entry);
+               else
+                       p = priv->dma_tx + entry;
 
                /* Check if the descriptor is owned by the DMA. */
                if (priv->hw->desc->get_tx_owner(p))
                        break;
 
-               /* Verify tx error by looking at the last segment */
+               /* Verify tx error by looking at the last segment. */
                last = priv->hw->desc->get_tx_ls(p);
                if (likely(last)) {
                        int tx_error =
-                               priv->hw->desc->tx_status(&priv->dev->stats,
-                                                         &priv->xstats, p,
-                                                         priv->ioaddr);
+                           priv->hw->desc->tx_status(&priv->dev->stats,
+                                                     &priv->xstats, p,
+                                                     priv->ioaddr);
                        if (likely(tx_error == 0)) {
                                priv->dev->stats.tx_packets++;
                                priv->xstats.tx_pkt_n++;
                        } else
                                priv->dev->stats.tx_errors++;
+
+                       stmmac_get_tx_hwtstamp(priv, entry, skb);
                }
                TX_DBG("%s: curr %d, dirty %d\n", __func__,
-                       priv->cur_tx, priv->dirty_tx);
+                      priv->cur_tx, priv->dirty_tx);
 
-               if (likely(p->des2))
-                       dma_unmap_single(priv->device, p->des2,
+               if (likely(priv->tx_skbuff_dma[entry])) {
+                       dma_unmap_single(priv->device,
+                                        priv->tx_skbuff_dma[entry],
                                         priv->hw->desc->get_tx_len(p),
                                         DMA_TO_DEVICE);
-               priv->hw->ring->clean_desc3(p);
+                       priv->tx_skbuff_dma[entry] = 0;
+               }
+               priv->hw->ring->clean_desc3(priv, p);
 
                if (likely(skb != NULL)) {
                        dev_kfree_skb(skb);
                        priv->tx_skbuff[entry] = NULL;
                }
 
-               priv->hw->desc->release_tx_desc(p);
+               priv->hw->desc->release_tx_desc(p, priv->mode);
 
                priv->dirty_tx++;
        }
@@ -749,7 +1268,7 @@ static void stmmac_tx_clean(struct stmmac_priv *priv)
                     stmmac_tx_avail(priv) > STMMAC_TX_THRESH(priv))) {
                netif_tx_lock(priv->dev);
                if (netif_queue_stopped(priv->dev) &&
-                    stmmac_tx_avail(priv) > STMMAC_TX_THRESH(priv)) {
+                   stmmac_tx_avail(priv) > STMMAC_TX_THRESH(priv)) {
                        TX_DBG("%s: restart transmit\n", __func__);
                        netif_wake_queue(priv->dev);
                }
@@ -773,20 +1292,29 @@ static inline void stmmac_disable_dma_irq(struct stmmac_priv *priv)
        priv->hw->dma->disable_dma_irq(priv->ioaddr);
 }
 
-
 /**
- * stmmac_tx_err:
- * @priv: pointer to the private device structure
+ * stmmac_tx_err: irq tx error mng function
+ * @priv: driver private structure
  * Description: it cleans the descriptors and restarts the transmission
  * in case of errors.
  */
 static void stmmac_tx_err(struct stmmac_priv *priv)
 {
+       int i;
+       int txsize = priv->dma_tx_size;
        netif_stop_queue(priv->dev);
 
        priv->hw->dma->stop_tx(priv->ioaddr);
        dma_free_tx_skbufs(priv);
-       priv->hw->desc->init_tx_desc(priv->dma_tx, priv->dma_tx_size);
+       for (i = 0; i < txsize; i++)
+               if (priv->extend_desc)
+                       priv->hw->desc->init_tx_desc(&priv->dma_etx[i].basic,
+                                                    priv->mode,
+                                                    (i == txsize - 1));
+               else
+                       priv->hw->desc->init_tx_desc(&priv->dma_tx[i],
+                                                    priv->mode,
+                                                    (i == txsize - 1));
        priv->dirty_tx = 0;
        priv->cur_tx = 0;
        priv->hw->dma->start_tx(priv->ioaddr);
@@ -795,6 +1323,14 @@ static void stmmac_tx_err(struct stmmac_priv *priv)
        netif_wake_queue(priv->dev);
 }
 
+/**
+ * stmmac_dma_interrupt: DMA ISR
+ * @priv: driver private structure
+ * Description: this is the DMA ISR. It is called by the main ISR.
+ * It calls the dwmac dma routine to understand which type of interrupt
+ * happened. In case of there is a Normal interrupt and either TX or RX
+ * interrupt happened so the NAPI is scheduled.
+ */
 static void stmmac_dma_interrupt(struct stmmac_priv *priv)
 {
        int status;
@@ -817,13 +1353,16 @@ static void stmmac_dma_interrupt(struct stmmac_priv *priv)
                stmmac_tx_err(priv);
 }
 
+/**
+ * stmmac_mmc_setup: setup the Mac Management Counters (MMC)
+ * @priv: driver private structure
+ * Description: this masks the MMC irq, in fact, the counters are managed in SW.
+ */
 static void stmmac_mmc_setup(struct stmmac_priv *priv)
 {
        unsigned int mode = MMC_CNTRL_RESET_ON_READ | MMC_CNTRL_COUNTER_RESET |
-                           MMC_CNTRL_PRESET | MMC_CNTRL_FULL_HALF_PRESET;
+           MMC_CNTRL_PRESET | MMC_CNTRL_FULL_HALF_PRESET;
 
-       /* Mask MMC irq, counters are managed in SW and registers
-        * are cleared on each READ eventually. */
        dwmac_mmc_intr_all_mask(priv->ioaddr);
 
        if (priv->dma_cap.rmon) {
@@ -837,8 +1376,7 @@ static u32 stmmac_get_synopsys_id(struct stmmac_priv *priv)
 {
        u32 hwid = priv->hw->synopsys_uid;
 
-       /* Only check valid Synopsys Id because old MAC chips
-        * have no HW registers where get the ID */
+       /* Check Synopsys Id (not available on old chips) */
        if (likely(hwid)) {
                u32 uid = ((hwid & 0x0000ff00) >> 8);
                u32 synid = (hwid & 0x000000ff);
@@ -852,14 +1390,24 @@ static u32 stmmac_get_synopsys_id(struct stmmac_priv *priv)
 }
 
 /**
- * stmmac_selec_desc_mode
- * @priv : private structure
- * Description: select the Enhanced/Alternate or Normal descriptors
+ * stmmac_selec_desc_mode: to select among: normal/alternate/extend descriptors
+ * @priv: driver private structure
+ * Description: select the Enhanced/Alternate or Normal descriptors.
+ * In case of Enhanced/Alternate, it looks at the extended descriptors are
+ * supported by the HW cap. register.
  */
 static void stmmac_selec_desc_mode(struct stmmac_priv *priv)
 {
        if (priv->plat->enh_desc) {
                pr_info(" Enhanced/Alternate descriptors\n");
+
+               /* GMAC older than 3.50 has no extended descriptors */
+               if (priv->synopsys_id >= DWMAC_CORE_3_50) {
+                       pr_info("\tEnabled extended descriptors\n");
+                       priv->extend_desc = 1;
+               } else
+                       pr_warn("Extended descriptors not supported\n");
+
                priv->hw->desc = &enh_desc_ops;
        } else {
                pr_info(" Normal descriptors\n");
@@ -868,8 +1416,8 @@ static void stmmac_selec_desc_mode(struct stmmac_priv *priv)
 }
 
 /**
- * stmmac_get_hw_features
- * @priv : private device pointer
+ * stmmac_get_hw_features: get MAC capabilities from the HW cap. register.
+ * @priv: driver private structure
  * Description:
  *  new GMAC chip generations have a new register to indicate the
  *  presence of the optional feature/functions.
@@ -887,69 +1435,78 @@ static int stmmac_get_hw_features(struct stmmac_priv *priv)
                priv->dma_cap.mbps_1000 = (hw_cap & DMA_HW_FEAT_GMIISEL) >> 1;
                priv->dma_cap.half_duplex = (hw_cap & DMA_HW_FEAT_HDSEL) >> 2;
                priv->dma_cap.hash_filter = (hw_cap & DMA_HW_FEAT_HASHSEL) >> 4;
-               priv->dma_cap.multi_addr =
-                       (hw_cap & DMA_HW_FEAT_ADDMACADRSEL) >> 5;
+               priv->dma_cap.multi_addr = (hw_cap & DMA_HW_FEAT_ADDMAC) >> 5;
                priv->dma_cap.pcs = (hw_cap & DMA_HW_FEAT_PCSSEL) >> 6;
                priv->dma_cap.sma_mdio = (hw_cap & DMA_HW_FEAT_SMASEL) >> 8;
                priv->dma_cap.pmt_remote_wake_up =
-                       (hw_cap & DMA_HW_FEAT_RWKSEL) >> 9;
+                   (hw_cap & DMA_HW_FEAT_RWKSEL) >> 9;
                priv->dma_cap.pmt_magic_frame =
-                       (hw_cap & DMA_HW_FEAT_MGKSEL) >> 10;
+                   (hw_cap & DMA_HW_FEAT_MGKSEL) >> 10;
                /* MMC */
                priv->dma_cap.rmon = (hw_cap & DMA_HW_FEAT_MMCSEL) >> 11;
-               /* IEEE 1588-2002*/
+               /* IEEE 1588-2002 */
                priv->dma_cap.time_stamp =
-                       (hw_cap & DMA_HW_FEAT_TSVER1SEL) >> 12;
-               /* IEEE 1588-2008*/
+                   (hw_cap & DMA_HW_FEAT_TSVER1SEL) >> 12;
+               /* IEEE 1588-2008 */
                priv->dma_cap.atime_stamp =
-                       (hw_cap & DMA_HW_FEAT_TSVER2SEL) >> 13;
+                   (hw_cap & DMA_HW_FEAT_TSVER2SEL) >> 13;
                /* 802.3az - Energy-Efficient Ethernet (EEE) */
                priv->dma_cap.eee = (hw_cap & DMA_HW_FEAT_EEESEL) >> 14;
                priv->dma_cap.av = (hw_cap & DMA_HW_FEAT_AVSEL) >> 15;
                /* TX and RX csum */
                priv->dma_cap.tx_coe = (hw_cap & DMA_HW_FEAT_TXCOESEL) >> 16;
                priv->dma_cap.rx_coe_type1 =
-                       (hw_cap & DMA_HW_FEAT_RXTYP1COE) >> 17;
+                   (hw_cap & DMA_HW_FEAT_RXTYP1COE) >> 17;
                priv->dma_cap.rx_coe_type2 =
-                       (hw_cap & DMA_HW_FEAT_RXTYP2COE) >> 18;
+                   (hw_cap & DMA_HW_FEAT_RXTYP2COE) >> 18;
                priv->dma_cap.rxfifo_over_2048 =
-                       (hw_cap & DMA_HW_FEAT_RXFIFOSIZE) >> 19;
+                   (hw_cap & DMA_HW_FEAT_RXFIFOSIZE) >> 19;
                /* TX and RX number of channels */
                priv->dma_cap.number_rx_channel =
-                       (hw_cap & DMA_HW_FEAT_RXCHCNT) >> 20;
+                   (hw_cap & DMA_HW_FEAT_RXCHCNT) >> 20;
                priv->dma_cap.number_tx_channel =
-                       (hw_cap & DMA_HW_FEAT_TXCHCNT) >> 22;
-               /* Alternate (enhanced) DESC mode*/
-               priv->dma_cap.enh_desc =
-                       (hw_cap & DMA_HW_FEAT_ENHDESSEL) >> 24;
+                   (hw_cap & DMA_HW_FEAT_TXCHCNT) >> 22;
+               /* Alternate (enhanced) DESC mode */
+               priv->dma_cap.enh_desc = (hw_cap & DMA_HW_FEAT_ENHDESSEL) >> 24;
        }
 
        return hw_cap;
 }
 
+/**
+ * stmmac_check_ether_addr: check if the MAC addr is valid
+ * @priv: driver private structure
+ * Description:
+ * it is to verify if the MAC address is valid, in case of failures it
+ * generates a random MAC address
+ */
 static void stmmac_check_ether_addr(struct stmmac_priv *priv)
 {
-       /* verify if the MAC address is valid, in case of failures it
-        * generates a random MAC address */
        if (!is_valid_ether_addr(priv->dev->dev_addr)) {
                priv->hw->mac->get_umac_addr((void __iomem *)
                                             priv->dev->base_addr,
                                             priv->dev->dev_addr, 0);
-               if  (!is_valid_ether_addr(priv->dev->dev_addr))
+               if (!is_valid_ether_addr(priv->dev->dev_addr))
                        eth_hw_addr_random(priv->dev);
        }
-       pr_warning("%s: device MAC address %pM\n", priv->dev->name,
-                                                  priv->dev->dev_addr);
+       pr_warn("%s: device MAC address %pM\n", priv->dev->name,
+               priv->dev->dev_addr);
 }
 
+/**
+ * stmmac_init_dma_engine: DMA init.
+ * @priv: driver private structure
+ * Description:
+ * It inits the DMA invoking the specific MAC/GMAC callback.
+ * Some DMA parameters can be passed from the platform;
+ * in case of these are not passed a default is kept for the MAC or GMAC.
+ */
 static int stmmac_init_dma_engine(struct stmmac_priv *priv)
 {
        int pbl = DEFAULT_DMA_PBL, fixed_burst = 0, burst_len = 0;
        int mixed_burst = 0;
+       int atds = 0;
 
-       /* Some DMA parameters can be passed from the platform;
-        * in case of these are not passed we keep a default
-        * (good for all the chips) and init the DMA! */
        if (priv->plat->dma_cfg) {
                pbl = priv->plat->dma_cfg->pbl;
                fixed_burst = priv->plat->dma_cfg->fixed_burst;
@@ -957,13 +1514,16 @@ static int stmmac_init_dma_engine(struct stmmac_priv *priv)
                burst_len = priv->plat->dma_cfg->burst_len;
        }
 
+       if (priv->extend_desc && (priv->mode == STMMAC_RING_MODE))
+               atds = 1;
+
        return priv->hw->dma->init(priv->ioaddr, pbl, fixed_burst, mixed_burst,
                                   burst_len, priv->dma_tx_phy,
-                                  priv->dma_rx_phy);
+                                  priv->dma_rx_phy, atds);
 }
 
 /**
- * stmmac_tx_timer:
+ * stmmac_tx_timer: mitigation sw timer for tx.
  * @data: data pointer
  * Description:
  * This is the timer handler to directly invoke the stmmac_tx_clean.
@@ -976,8 +1536,8 @@ static void stmmac_tx_timer(unsigned long data)
 }
 
 /**
- * stmmac_tx_timer:
- * @priv: private data structure
+ * stmmac_init_tx_coalesce: init tx mitigation options.
+ * @priv: driver private structure
  * Description:
  * This inits the transmit coalesce parameters: i.e. timer rate,
  * timer handler and default threshold used for enabling the
@@ -1012,10 +1572,14 @@ static int stmmac_open(struct net_device *dev)
 
        stmmac_check_ether_addr(priv);
 
-       ret = stmmac_init_phy(dev);
-       if (unlikely(ret)) {
-               pr_err("%s: Cannot attach to PHY (error: %d)\n", __func__, ret);
-               goto open_error;
+       if (priv->pcs != STMMAC_PCS_RGMII && priv->pcs != STMMAC_PCS_TBI &&
+           priv->pcs != STMMAC_PCS_RTBI) {
+               ret = stmmac_init_phy(dev);
+               if (ret) {
+                       pr_err("%s: Cannot attach to PHY (error: %d)\n",
+                              __func__, ret);
+                       goto open_error;
+               }
        }
 
        /* Create and initialize the TX/RX descriptors chains. */
@@ -1043,7 +1607,7 @@ static int stmmac_open(struct net_device *dev)
 
        /* Request the IRQ lines */
        ret = request_irq(dev->irq, stmmac_interrupt,
-                        IRQF_SHARED, dev->name, dev);
+                         IRQF_SHARED, dev->name, dev);
        if (unlikely(ret < 0)) {
                pr_err("%s: ERROR: allocating the IRQ %d (error: %d)\n",
                       __func__, dev->irq, ret);
@@ -1055,8 +1619,8 @@ static int stmmac_open(struct net_device *dev)
                ret = request_irq(priv->wol_irq, stmmac_interrupt,
                                  IRQF_SHARED, dev->name, dev);
                if (unlikely(ret < 0)) {
-                       pr_err("%s: ERROR: allocating the ext WoL IRQ %d "
-                              "(error: %d)\n", __func__, priv->wol_irq, ret);
+                       pr_err("%s: ERROR: allocating the WoL IRQ %d (%d)\n",
+                              __func__, priv->wol_irq, ret);
                        goto open_error_wolirq;
                }
        }
@@ -1084,10 +1648,14 @@ static int stmmac_open(struct net_device *dev)
 
        stmmac_mmc_setup(priv);
 
+       ret = stmmac_init_ptp(priv);
+       if (ret)
+               pr_warn("%s: failed PTP initialisation\n", __func__);
+
 #ifdef CONFIG_STMMAC_DEBUG_FS
        ret = stmmac_init_fs(dev);
        if (ret < 0)
-               pr_warning("%s: failed debugFS registration\n", __func__);
+               pr_warn("%s: failed debugFS registration\n", __func__);
 #endif
        /* Start the ball rolling... */
        DBG(probe, DEBUG, "%s: DMA RX/TX processes started...\n", dev->name);
@@ -1104,7 +1672,13 @@ static int stmmac_open(struct net_device *dev)
                phy_start(priv->phydev);
 
        priv->tx_lpi_timer = STMMAC_DEFAULT_TWT_LS_TIMER;
-       priv->eee_enabled = stmmac_eee_init(priv);
+
+       /* Using PCS we cannot dial with the phy registers at this stage
+        * so we do not support extra feature like EEE.
+        */
+       if (priv->pcs != STMMAC_PCS_RGMII && priv->pcs != STMMAC_PCS_TBI &&
+           priv->pcs != STMMAC_PCS_RTBI)
+               priv->eee_enabled = stmmac_eee_init(priv);
 
        stmmac_init_tx_coalesce(priv);
 
@@ -1113,6 +1687,9 @@ static int stmmac_open(struct net_device *dev)
                priv->hw->dma->rx_watchdog(priv->ioaddr, MAX_DMA_RIWT);
        }
 
+       if (priv->pcs && priv->hw->mac->ctrl_ane)
+               priv->hw->mac->ctrl_ane(priv->ioaddr, 0);
+
        napi_enable(&priv->napi);
        netif_start_queue(dev);
 
@@ -1184,21 +1761,25 @@ static int stmmac_release(struct net_device *dev)
 #endif
        clk_disable_unprepare(priv->stmmac_clk);
 
+       stmmac_release_ptp(priv);
+
        return 0;
 }
 
 /**
- *  stmmac_xmit:
+ *  stmmac_xmit: Tx entry point of the driver
  *  @skb : the socket buffer
  *  @dev : device pointer
- *  Description : Tx entry point of the driver.
+ *  Description : this is the tx entry point of the driver.
+ *  It programs the chain or the ring and supports oversized frames
+ *  and SG feature.
  */
 static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 {
        struct stmmac_priv *priv = netdev_priv(dev);
        unsigned int txsize = priv->dma_tx_size;
        unsigned int entry;
-       int i, csum_insertion = 0;
+       int i, csum_insertion = 0, is_jumbo = 0;
        int nfrags = skb_shinfo(skb)->nr_frags;
        struct dma_desc *desc, *first;
        unsigned int nopaged_len = skb_headlen(skb);
@@ -1207,8 +1788,7 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
                if (!netif_queue_stopped(dev)) {
                        netif_stop_queue(dev);
                        /* This is a hard error, log it. */
-                       pr_err("%s: BUG! Tx Ring full when queue awake\n",
-                               __func__);
+                       pr_err("%s: Tx Ring full when queue awake\n", __func__);
                }
                return NETDEV_TX_BUSY;
        }
@@ -1222,10 +1802,9 @@ 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_debug("stmmac xmit: [entry %d]\n"
-                        "\tskb addr %p - len: %d - nopaged_len: %d\n"
+               pr_debug("%s: [entry %d]: skb addr %p len: %d nopagedlen: %d\n"
                         "\tn_frags: %d - ip_summed: %d - %s gso\n"
-                        "\ttx_count_frames %d\n", entry,
+                        "\ttx_count_frames %d\n", __func__, entry,
                         skb, skb->len, nopaged_len, nfrags, skb->ip_summed,
                         !skb_is_gso(skb) ? "isn't" : "is",
                         priv->tx_count_frames);
@@ -1233,7 +1812,11 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
        csum_insertion = (skb->ip_summed == CHECKSUM_PARTIAL);
 
-       desc = priv->dma_tx + entry;
+       if (priv->extend_desc)
+               desc = (struct dma_desc *)(priv->dma_etx + entry);
+       else
+               desc = priv->dma_tx + entry;
+
        first = desc;
 
 #ifdef STMMAC_XMIT_DEBUG
@@ -1244,28 +1827,46 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 #endif
        priv->tx_skbuff[entry] = skb;
 
-       if (priv->hw->ring->is_jumbo_frm(skb->len, priv->plat->enh_desc)) {
-               entry = priv->hw->ring->jumbo_frm(priv, skb, csum_insertion);
-               desc = priv->dma_tx + entry;
+       /* To program the descriptors according to the size of the frame */
+       if (priv->mode == STMMAC_RING_MODE) {
+               is_jumbo = priv->hw->ring->is_jumbo_frm(skb->len,
+                                                       priv->plat->enh_desc);
+               if (unlikely(is_jumbo))
+                       entry = priv->hw->ring->jumbo_frm(priv, skb,
+                                                         csum_insertion);
        } else {
+               is_jumbo = priv->hw->chain->is_jumbo_frm(skb->len,
+                                                        priv->plat->enh_desc);
+               if (unlikely(is_jumbo))
+                       entry = priv->hw->chain->jumbo_frm(priv, skb,
+                                                          csum_insertion);
+       }
+       if (likely(!is_jumbo)) {
                desc->des2 = dma_map_single(priv->device, skb->data,
-                                       nopaged_len, DMA_TO_DEVICE);
+                                           nopaged_len, DMA_TO_DEVICE);
+               priv->tx_skbuff_dma[entry] = desc->des2;
                priv->hw->desc->prepare_tx_desc(desc, 1, nopaged_len,
-                                               csum_insertion);
-       }
+                                               csum_insertion, priv->mode);
+       } else
+               desc = first;
 
        for (i = 0; i < nfrags; i++) {
                const skb_frag_t *frag = &skb_shinfo(skb)->frags[i];
                int len = skb_frag_size(frag);
 
                entry = (++priv->cur_tx) % txsize;
-               desc = priv->dma_tx + entry;
+               if (priv->extend_desc)
+                       desc = (struct dma_desc *)(priv->dma_etx + entry);
+               else
+                       desc = priv->dma_tx + entry;
 
                TX_DBG("\t[entry %d] segment len: %d\n", entry, len);
                desc->des2 = skb_frag_dma_map(priv->device, frag, 0, len,
                                              DMA_TO_DEVICE);
+               priv->tx_skbuff_dma[entry] = desc->des2;
                priv->tx_skbuff[entry] = NULL;
-               priv->hw->desc->prepare_tx_desc(desc, 0, len, csum_insertion);
+               priv->hw->desc->prepare_tx_desc(desc, 0, len, csum_insertion,
+                                               priv->mode);
                wmb();
                priv->hw->desc->set_tx_owner(desc);
                wmb();
@@ -1298,11 +1899,14 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
 #ifdef STMMAC_XMIT_DEBUG
        if (netif_msg_pktdata(priv)) {
-               pr_info("stmmac xmit: current=%d, dirty=%d, entry=%d, "
-                      "first=%p, nfrags=%d\n",
-                      (priv->cur_tx % txsize), (priv->dirty_tx % txsize),
-                      entry, first, nfrags);
-               display_ring(priv->dma_tx, txsize);
+               pr_info("%s: curr %d dirty=%d entry=%d, first=%p, nfrags=%d"
+                       __func__, (priv->cur_tx % txsize),
+                       (priv->dirty_tx % txsize), entry, first, nfrags);
+               if (priv->extend_desc)
+                       stmmac_display_ring((void *)priv->dma_etx, txsize, 1);
+               else
+                       stmmac_display_ring((void *)priv->dma_tx, txsize, 0);
+
                pr_info(">>> frame to be transmitted: ");
                print_pkt(skb->data, skb->len);
        }
@@ -1314,7 +1918,15 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
 
        dev->stats.tx_bytes += skb->len;
 
-       skb_tx_timestamp(skb);
+       if (unlikely((skb_shinfo(skb)->tx_flags & SKBTX_HW_TSTAMP) &&
+                    priv->hwts_tx_en)) {
+               /* declare that device is doing timestamping */
+               skb_shinfo(skb)->tx_flags |= SKBTX_IN_PROGRESS;
+               priv->hw->desc->enable_tx_timestamp(first);
+       }
+
+       if (!priv->hwts_tx_en)
+               skb_tx_timestamp(skb);
 
        priv->hw->dma->enable_dma_transmission(priv->ioaddr);
 
@@ -1323,14 +1935,26 @@ static netdev_tx_t stmmac_xmit(struct sk_buff *skb, struct net_device *dev)
        return NETDEV_TX_OK;
 }
 
+/**
+ * stmmac_rx_refill: refill used skb preallocated buffers
+ * @priv: driver private structure
+ * Description : this is to reallocate the skb for the reception process
+ * that is based on zero-copy.
+ */
 static inline void stmmac_rx_refill(struct stmmac_priv *priv)
 {
        unsigned int rxsize = priv->dma_rx_size;
        int bfsize = priv->dma_buf_sz;
-       struct dma_desc *p = priv->dma_rx;
 
        for (; priv->cur_rx - priv->dirty_rx > 0; priv->dirty_rx++) {
                unsigned int entry = priv->dirty_rx % rxsize;
+               struct dma_desc *p;
+
+               if (priv->extend_desc)
+                       p = (struct dma_desc *)(priv->dma_erx + entry);
+               else
+                       p = priv->dma_rx + entry;
+
                if (likely(priv->rx_skbuff[entry] == NULL)) {
                        struct sk_buff *skb;
 
@@ -1344,80 +1968,116 @@ static inline void stmmac_rx_refill(struct stmmac_priv *priv)
                            dma_map_single(priv->device, skb->data, bfsize,
                                           DMA_FROM_DEVICE);
 
-                       (p + entry)->des2 = priv->rx_skbuff_dma[entry];
+                       p->des2 = priv->rx_skbuff_dma[entry];
 
-                       if (unlikely(priv->plat->has_gmac))
-                               priv->hw->ring->refill_desc3(bfsize, p + entry);
+                       priv->hw->ring->refill_desc3(priv, p);
 
                        RX_DBG(KERN_INFO "\trefill entry #%d\n", entry);
                }
                wmb();
-               priv->hw->desc->set_rx_owner(p + entry);
+               priv->hw->desc->set_rx_owner(p);
                wmb();
        }
 }
 
+/**
+ * stmmac_rx_refill: refill used skb preallocated buffers
+ * @priv: driver private structure
+ * @limit: napi bugget.
+ * Description :  this the function called by the napi poll method.
+ * It gets all the frames inside the ring.
+ */
 static int stmmac_rx(struct stmmac_priv *priv, int limit)
 {
        unsigned int rxsize = priv->dma_rx_size;
        unsigned int entry = priv->cur_rx % rxsize;
        unsigned int next_entry;
        unsigned int count = 0;
-       struct dma_desc *p = priv->dma_rx + entry;
-       struct dma_desc *p_next;
+       int coe = priv->plat->rx_coe;
 
 #ifdef STMMAC_RX_DEBUG
        if (netif_msg_hw(priv)) {
                pr_debug(">>> stmmac_rx: descriptor ring:\n");
-               display_ring(priv->dma_rx, rxsize);
+               if (priv->extend_desc)
+                       stmmac_display_ring((void *)priv->dma_erx, rxsize, 1);
+               else
+                       stmmac_display_ring((void *)priv->dma_rx, rxsize, 0);
        }
 #endif
-       while (!priv->hw->desc->get_rx_owner(p)) {
+       while (count < limit) {
                int status;
+               struct dma_desc *p;
 
-               if (count >= limit)
+               if (priv->extend_desc)
+                       p = (struct dma_desc *)(priv->dma_erx + entry);
+               else
+                       p = priv->dma_rx + entry;
+
+               if (priv->hw->desc->get_rx_owner(p))
                        break;
 
                count++;
 
                next_entry = (++priv->cur_rx) % rxsize;
-               p_next = priv->dma_rx + next_entry;
-               prefetch(p_next);
+               if (priv->extend_desc)
+                       prefetch(priv->dma_erx + next_entry);
+               else
+                       prefetch(priv->dma_rx + next_entry);
 
                /* read the status of the incoming frame */
-               status = (priv->hw->desc->rx_status(&priv->dev->stats,
-                                                   &priv->xstats, p));
-               if (unlikely(status == discard_frame))
+               status = priv->hw->desc->rx_status(&priv->dev->stats,
+                                                  &priv->xstats, p);
+               if ((priv->extend_desc) && (priv->hw->desc->rx_extended_status))
+                       priv->hw->desc->rx_extended_status(&priv->dev->stats,
+                                                          &priv->xstats,
+                                                          priv->dma_erx +
+                                                          entry);
+               if (unlikely(status == discard_frame)) {
                        priv->dev->stats.rx_errors++;
-               else {
+                       if (priv->hwts_rx_en && !priv->extend_desc) {
+                               /* DESC2 & DESC3 will be overwitten by device
+                                * with timestamp value, hence reinitialize
+                                * them in stmmac_rx_refill() function so that
+                                * device can reuse it.
+                                */
+                               priv->rx_skbuff[entry] = NULL;
+                               dma_unmap_single(priv->device,
+                                                priv->rx_skbuff_dma[entry],
+                                                priv->dma_buf_sz,
+                                                DMA_FROM_DEVICE);
+                       }
+               } else {
                        struct sk_buff *skb;
                        int frame_len;
 
-                       frame_len = priv->hw->desc->get_rx_frame_len(p,
-                                       priv->plat->rx_coe);
+                       frame_len = priv->hw->desc->get_rx_frame_len(p, coe);
+
                        /* ACS is set; GMAC core strips PAD/FCS for IEEE 802.3
-                        * Type frames (LLC/LLC-SNAP) */
+                        * Type frames (LLC/LLC-SNAP)
+                        */
                        if (unlikely(status != llc_snap))
                                frame_len -= ETH_FCS_LEN;
 #ifdef STMMAC_RX_DEBUG
                        if (frame_len > ETH_FRAME_LEN)
                                pr_debug("\tRX frame size %d, COE status: %d\n",
-                                       frame_len, status);
+                                        frame_len, status);
 
                        if (netif_msg_hw(priv))
                                pr_debug("\tdesc: %p [entry %d] buff=0x%x\n",
-                                       p, entry, p->des2);
+                                        p, entry, p->des2);
 #endif
                        skb = priv->rx_skbuff[entry];
                        if (unlikely(!skb)) {
                                pr_err("%s: Inconsistent Rx descriptor chain\n",
-                                       priv->dev->name);
+                                      priv->dev->name);
                                priv->dev->stats.rx_dropped++;
                                break;
                        }
                        prefetch(skb->data - NET_IP_ALIGN);
                        priv->rx_skbuff[entry] = NULL;
 
+                       stmmac_get_rx_hwtstamp(priv, entry, skb);
+
                        skb_put(skb, frame_len);
                        dma_unmap_single(priv->device,
                                         priv->rx_skbuff_dma[entry],
@@ -1430,7 +2090,7 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit)
 #endif
                        skb->protocol = eth_type_trans(skb, priv->dev);
 
-                       if (unlikely(!priv->plat->rx_coe))
+                       if (unlikely(!coe))
                                skb_checksum_none_assert(skb);
                        else
                                skb->ip_summed = CHECKSUM_UNNECESSARY;
@@ -1441,7 +2101,6 @@ static int stmmac_rx(struct stmmac_priv *priv, int limit)
                        priv->dev->stats.rx_bytes += frame_len;
                }
                entry = next_entry;
-               p = p_next;     /* use prefetched values */
        }
 
        stmmac_rx_refill(priv);
@@ -1499,18 +2158,16 @@ static int stmmac_config(struct net_device *dev, struct ifmap *map)
 
        /* Don't allow changing the I/O address */
        if (map->base_addr != dev->base_addr) {
-               pr_warning("%s: can't change I/O address\n", dev->name);
+               pr_warn("%s: can't change I/O address\n", dev->name);
                return -EOPNOTSUPP;
        }
 
        /* Don't allow changing the IRQ */
        if (map->irq != dev->irq) {
-               pr_warning("%s: can't change IRQ number %d\n",
-                      dev->name, dev->irq);
+               pr_warn("%s: not change IRQ number %d\n", dev->name, dev->irq);
                return -EOPNOTSUPP;
        }
 
-       /* ignore other fields */
        return 0;
 }
 
@@ -1570,7 +2227,7 @@ static int stmmac_change_mtu(struct net_device *dev, int new_mtu)
 }
 
 static netdev_features_t stmmac_fix_features(struct net_device *dev,
-       netdev_features_t features)
+                                            netdev_features_t features)
 {
        struct stmmac_priv *priv = netdev_priv(dev);
 
@@ -1584,13 +2241,22 @@ static netdev_features_t stmmac_fix_features(struct net_device *dev,
        /* Some GMAC devices have a bugged Jumbo frame support that
         * needs to have the Tx COE disabled for oversized frames
         * (due to limited buffer sizes). In this case we disable
-        * the TX csum insertionin the TDES and not use SF. */
+        * the TX csum insertionin the TDES and not use SF.
+        */
        if (priv->plat->bugged_jumbo && (dev->mtu > ETH_DATA_LEN))
                features &= ~NETIF_F_ALL_CSUM;
 
        return features;
 }
 
+/**
+ *  stmmac_interrupt - main ISR
+ *  @irq: interrupt number.
+ *  @dev_id: to pass the net device pointer.
+ *  Description: this is the main driver interrupt service routine.
+ *  It calls the DMA ISR and also the core ISR to manage PMT, MMC, LPI
+ *  interrupts.
+ */
 static irqreturn_t stmmac_interrupt(int irq, void *dev_id)
 {
        struct net_device *dev = (struct net_device *)dev_id;
@@ -1604,30 +2270,14 @@ static irqreturn_t stmmac_interrupt(int irq, void *dev_id)
        /* To handle GMAC own interrupts */
        if (priv->plat->has_gmac) {
                int status = priv->hw->mac->host_irq_status((void __iomem *)
-                                                           dev->base_addr);
+                                                           dev->base_addr,
+                                                           &priv->xstats);
                if (unlikely(status)) {
-                       if (status & core_mmc_tx_irq)
-                               priv->xstats.mmc_tx_irq_n++;
-                       if (status & core_mmc_rx_irq)
-                               priv->xstats.mmc_rx_irq_n++;
-                       if (status & core_mmc_rx_csum_offload_irq)
-                               priv->xstats.mmc_rx_csum_offload_irq_n++;
-                       if (status & core_irq_receive_pmt_irq)
-                               priv->xstats.irq_receive_pmt_irq_n++;
-
                        /* For LPI we need to save the tx status */
-                       if (status & core_irq_tx_path_in_lpi_mode) {
-                               priv->xstats.irq_tx_path_in_lpi_mode_n++;
+                       if (status & CORE_IRQ_TX_PATH_IN_LPI_MODE)
                                priv->tx_path_in_lpi_mode = true;
-                       }
-                       if (status & core_irq_tx_path_exit_lpi_mode) {
-                               priv->xstats.irq_tx_path_exit_lpi_mode_n++;
+                       if (status & CORE_IRQ_TX_PATH_EXIT_LPI_MODE)
                                priv->tx_path_in_lpi_mode = false;
-                       }
-                       if (status & core_irq_rx_path_in_lpi_mode)
-                               priv->xstats.irq_rx_path_in_lpi_mode_n++;
-                       if (status & core_irq_rx_path_exit_lpi_mode)
-                               priv->xstats.irq_rx_path_exit_lpi_mode_n++;
                }
        }
 
@@ -1639,7 +2289,8 @@ static irqreturn_t stmmac_interrupt(int irq, void *dev_id)
 
 #ifdef CONFIG_NET_POLL_CONTROLLER
 /* Polling receive - used by NETCONSOLE and other diagnostic tools
- * to allow network I/O with interrupts disabled. */
+ * to allow network I/O with interrupts disabled.
+ */
 static void stmmac_poll_controller(struct net_device *dev)
 {
        disable_irq(dev->irq);
@@ -1655,21 +2306,30 @@ static void stmmac_poll_controller(struct net_device *dev)
  *  a proprietary structure used to pass information to the driver.
  *  @cmd: IOCTL command
  *  Description:
- *  Currently there are no special functionality supported in IOCTL, just the
- *  phy_mii_ioctl(...) can be invoked.
+ *  Currently it supports the phy_mii_ioctl(...) and HW time stamping.
  */
 static int stmmac_ioctl(struct net_device *dev, struct ifreq *rq, int cmd)
 {
        struct stmmac_priv *priv = netdev_priv(dev);
-       int ret;
+       int ret = -EOPNOTSUPP;
 
        if (!netif_running(dev))
                return -EINVAL;
 
-       if (!priv->phydev)
-               return -EINVAL;
-
-       ret = phy_mii_ioctl(priv->phydev, rq, cmd);
+       switch (cmd) {
+       case SIOCGMIIPHY:
+       case SIOCGMIIREG:
+       case SIOCSMIIREG:
+               if (!priv->phydev)
+                       return -EINVAL;
+               ret = phy_mii_ioctl(priv->phydev, rq, cmd);
+               break;
+       case SIOCSHWTSTAMP:
+               ret = stmmac_hwtstamp_ioctl(dev, rq);
+               break;
+       default:
+               break;
+       }
 
        return ret;
 }
@@ -1679,40 +2339,51 @@ static struct dentry *stmmac_fs_dir;
 static struct dentry *stmmac_rings_status;
 static struct dentry *stmmac_dma_cap;
 
-static int stmmac_sysfs_ring_read(struct seq_file *seq, void *v)
+static void sysfs_display_ring(void *head, int size, int extend_desc,
+                              struct seq_file *seq)
 {
-       struct tmp_s {
-               u64 a;
-               unsigned int b;
-               unsigned int c;
-       };
        int i;
-       struct net_device *dev = seq->private;
-       struct stmmac_priv *priv = netdev_priv(dev);
+       struct dma_extended_desc *ep = (struct dma_extended_desc *)head;
+       struct dma_desc *p = (struct dma_desc *)head;
 
-       seq_printf(seq, "=======================\n");
-       seq_printf(seq, " RX descriptor ring\n");
-       seq_printf(seq, "=======================\n");
-
-       for (i = 0; i < priv->dma_rx_size; i++) {
-               struct tmp_s *x = (struct tmp_s *)(priv->dma_rx + i);
-               seq_printf(seq, "[%d] DES0=0x%x DES1=0x%x BUF1=0x%x BUF2=0x%x",
-                          i, (unsigned int)(x->a),
-                          (unsigned int)((x->a) >> 32), x->b, x->c);
+       for (i = 0; i < size; i++) {
+               u64 x;
+               if (extend_desc) {
+                       x = *(u64 *) ep;
+                       seq_printf(seq, "%d [0x%x]: 0x%x 0x%x 0x%x 0x%x\n",
+                                  i, (unsigned int)virt_to_phys(ep),
+                                  (unsigned int)x, (unsigned int)(x >> 32),
+                                  ep->basic.des2, ep->basic.des3);
+                       ep++;
+               } else {
+                       x = *(u64 *) p;
+                       seq_printf(seq, "%d [0x%x]: 0x%x 0x%x 0x%x 0x%x\n",
+                                  i, (unsigned int)virt_to_phys(ep),
+                                  (unsigned int)x, (unsigned int)(x >> 32),
+                                  p->des2, p->des3);
+                       p++;
+               }
                seq_printf(seq, "\n");
        }
+}
 
-       seq_printf(seq, "\n");
-       seq_printf(seq, "=======================\n");
-       seq_printf(seq, "  TX descriptor ring\n");
-       seq_printf(seq, "=======================\n");
+static int stmmac_sysfs_ring_read(struct seq_file *seq, void *v)
+{
+       struct net_device *dev = seq->private;
+       struct stmmac_priv *priv = netdev_priv(dev);
+       unsigned int txsize = priv->dma_tx_size;
+       unsigned int rxsize = priv->dma_rx_size;
 
-       for (i = 0; i < priv->dma_tx_size; i++) {
-               struct tmp_s *x = (struct tmp_s *)(priv->dma_tx + i);
-               seq_printf(seq, "[%d] DES0=0x%x DES1=0x%x BUF1=0x%x BUF2=0x%x",
-                          i, (unsigned int)(x->a),
-                          (unsigned int)((x->a) >> 32), x->b, x->c);
-               seq_printf(seq, "\n");
+       if (priv->extend_desc) {
+               seq_printf(seq, "Extended RX descriptor ring:\n");
+               sysfs_display_ring((void *)priv->dma_erx, rxsize, 1, seq);
+               seq_printf(seq, "Extended TX descriptor ring:\n");
+               sysfs_display_ring((void *)priv->dma_etx, txsize, 1, seq);
+       } else {
+               seq_printf(seq, "RX descriptor ring:\n");
+               sysfs_display_ring((void *)priv->dma_rx, rxsize, 0, seq);
+               seq_printf(seq, "TX descriptor ring:\n");
+               sysfs_display_ring((void *)priv->dma_tx, txsize, 0, seq);
        }
 
        return 0;
@@ -1817,8 +2488,8 @@ static int stmmac_init_fs(struct net_device *dev)
 
        /* Entry to report DMA RX/TX rings */
        stmmac_rings_status = debugfs_create_file("descriptors_status",
-                                          S_IRUGO, stmmac_fs_dir, dev,
-                                          &stmmac_rings_status_fops);
+                                                 S_IRUGO, stmmac_fs_dir, dev,
+                                                 &stmmac_rings_status_fops);
 
        if (!stmmac_rings_status || IS_ERR(stmmac_rings_status)) {
                pr_info("ERROR creating stmmac ring debugfs file\n");
@@ -1868,7 +2539,7 @@ static const struct net_device_ops stmmac_netdev_ops = {
 
 /**
  *  stmmac_hw_init - Init the MAC device
- *  @priv : pointer to the private device structure.
+ *  @priv: driver private structure
  *  Description: this function detects which MAC device
  *  (GMAC/MAC10-100) has to attached, checks the HW capability
  *  (if supported) and sets the driver's features (for example
@@ -1877,7 +2548,7 @@ static const struct net_device_ops stmmac_netdev_ops = {
  */
 static int stmmac_hw_init(struct stmmac_priv *priv)
 {
-       int ret = 0;
+       int ret;
        struct mac_device_info *mac;
 
        /* Identify the MAC HW device */
@@ -1892,12 +2563,23 @@ static int stmmac_hw_init(struct stmmac_priv *priv)
 
        priv->hw = mac;
 
-       /* To use the chained or ring mode */
-       priv->hw->ring = &ring_mode_ops;
-
        /* Get and dump the chip ID */
        priv->synopsys_id = stmmac_get_synopsys_id(priv);
 
+       /* To use alternate (extended) or normal descriptor structures */
+       stmmac_selec_desc_mode(priv);
+
+       /* To use the chained or ring mode */
+       if (chain_mode) {
+               priv->hw->chain = &chain_mode_ops;
+               pr_info(" Chain mode enabled\n");
+               priv->mode = STMMAC_CHAIN_MODE;
+       } else {
+               priv->hw->ring = &ring_mode_ops;
+               pr_info(" Ring mode enabled\n");
+               priv->mode = STMMAC_RING_MODE;
+       }
+
        /* Get the HW capability (new GMAC newer than 3.50a) */
        priv->hw_cap_support = stmmac_get_hw_features(priv);
        if (priv->hw_cap_support) {
@@ -1921,14 +2603,9 @@ static int stmmac_hw_init(struct stmmac_priv *priv)
        } else
                pr_info(" No HW DMA feature register supported");
 
-       /* Select the enhnaced/normal descriptor structures */
-       stmmac_selec_desc_mode(priv);
-
-       /* Enable the IPC (Checksum Offload) and check if the feature has been
-        * enabled during the core configuration. */
        ret = priv->hw->mac->rx_ipc(priv->ioaddr);
        if (!ret) {
-               pr_warning(" RX IPC Checksum Offload not configured.\n");
+               pr_warn(" RX IPC Checksum Offload not configured.\n");
                priv->plat->rx_coe = STMMAC_RX_COE_NONE;
        }
 
@@ -1943,7 +2620,7 @@ static int stmmac_hw_init(struct stmmac_priv *priv)
                device_set_wakeup_capable(priv->device, 1);
        }
 
-       return ret;
+       return 0;
 }
 
 /**
@@ -1984,12 +2661,15 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device,
        stmmac_verify_args();
 
        /* Override with kernel parameters if supplied XXX CRS XXX
-        * this needs to have multiple instances */
+        * this needs to have multiple instances
+        */
        if ((phyaddr >= 0) && (phyaddr <= 31))
                priv->plat->phy_addr = phyaddr;
 
        /* Init MAC and get the capabilities */
-       stmmac_hw_init(priv);
+       ret = stmmac_hw_init(priv);
+       if (ret)
+               goto error_free_netdev;
 
        ndev->netdev_ops = &stmmac_netdev_ops;
 
@@ -2029,7 +2709,7 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device,
 
        priv->stmmac_clk = clk_get(priv->device, STMMAC_RESOURCE_NAME);
        if (IS_ERR(priv->stmmac_clk)) {
-               pr_warning("%s: warning: cannot get CSR clock\n", __func__);
+               pr_warn("%s: warning: cannot get CSR clock\n", __func__);
                goto error_clk_get;
        }
 
@@ -2044,12 +2724,17 @@ struct stmmac_priv *stmmac_dvr_probe(struct device *device,
        else
                priv->clk_csr = priv->plat->clk_csr;
 
-       /* MDIO bus Registration */
-       ret = stmmac_mdio_register(ndev);
-       if (ret < 0) {
-               pr_debug("%s: MDIO bus (id: %d) registration failed",
-                        __func__, priv->plat->bus_id);
-               goto error_mdio_register;
+       stmmac_check_pcs_mode(priv);
+
+       if (priv->pcs != STMMAC_PCS_RGMII && priv->pcs != STMMAC_PCS_TBI &&
+           priv->pcs != STMMAC_PCS_RTBI) {
+               /* MDIO bus Registration */
+               ret = stmmac_mdio_register(ndev);
+               if (ret < 0) {
+                       pr_debug("%s: MDIO bus (id: %d) registration failed",
+                                __func__, priv->plat->bus_id);
+                       goto error_mdio_register;
+               }
        }
 
        return priv;
@@ -2060,6 +2745,7 @@ error_clk_get:
        unregister_netdev(ndev);
 error_netdev_register:
        netif_napi_del(&priv->napi);
+error_free_netdev:
        free_netdev(ndev);
 
        return NULL;
@@ -2081,7 +2767,9 @@ int stmmac_dvr_remove(struct net_device *ndev)
        priv->hw->dma->stop_tx(priv->ioaddr);
 
        stmmac_set_mac(priv->ioaddr, false);
-       stmmac_mdio_unregister(ndev);
+       if (priv->pcs != STMMAC_PCS_RGMII && priv->pcs != STMMAC_PCS_TBI &&
+           priv->pcs != STMMAC_PCS_RTBI)
+               stmmac_mdio_unregister(ndev);
        netif_carrier_off(ndev);
        unregister_netdev(ndev);
        free_netdev(ndev);
@@ -2093,7 +2781,6 @@ int stmmac_dvr_remove(struct net_device *ndev)
 int stmmac_suspend(struct net_device *ndev)
 {
        struct stmmac_priv *priv = netdev_priv(ndev);
-       int dis_ic = 0;
        unsigned long flags;
 
        if (!ndev || !netif_running(ndev))
@@ -2107,18 +2794,13 @@ int stmmac_suspend(struct net_device *ndev)
        netif_device_detach(ndev);
        netif_stop_queue(ndev);
 
-       if (priv->use_riwt)
-               dis_ic = 1;
-
        napi_disable(&priv->napi);
 
        /* Stop TX/RX DMA */
        priv->hw->dma->stop_tx(priv->ioaddr);
        priv->hw->dma->stop_rx(priv->ioaddr);
-       /* Clear the Rx/Tx descriptors */
-       priv->hw->desc->init_rx_desc(priv->dma_rx, priv->dma_rx_size,
-                                    dis_ic);
-       priv->hw->desc->init_tx_desc(priv->dma_tx, priv->dma_tx_size);
+
+       stmmac_clear_descriptors(priv);
 
        /* Enable Power down mode by programming the PMT regs */
        if (device_may_wakeup(priv->device))
@@ -2146,7 +2828,8 @@ int stmmac_resume(struct net_device *ndev)
         * automatically as soon as a magic packet or a Wake-up frame
         * is received. Anyway, it's better to manually clear
         * this bit because it can generate problems while resuming
-        * from another devices (e.g. serial console). */
+        * from another devices (e.g. serial console).
+        */
        if (device_may_wakeup(priv->device))
                priv->hw->mac->pmt(priv->ioaddr, 0);
        else
@@ -2257,6 +2940,9 @@ static int __init stmmac_cmdline_opt(char *str)
                } else if (!strncmp(opt, "eee_timer:", 10)) {
                        if (kstrtoint(opt + 10, 0, &eee_timer))
                                goto err;
+               } else if (!strncmp(opt, "chain_mode:", 11)) {
+                       if (kstrtoint(opt + 11, 0, &chain_mode))
+                               goto err;
                }
        }
        return 0;
@@ -2267,7 +2953,7 @@ err:
 }
 
 __setup("stmmaceth=", stmmac_cmdline_opt);
-#endif
+#endif /* MODULE */
 
 MODULE_DESCRIPTION("STMMAC 10/100/1000 Ethernet device driver");
 MODULE_AUTHOR("Giuseppe Cavallaro <peppe.cavallaro@st.com>");