drivers/net/ethernet/stmicro/stmmac/enh_desc.c - kernel/msm-4.19 - Gitiles

 /*******************************************************************************
   This contains the functions to handle the enhanced descriptors.

   Copyright (C) 2007-2014  STMicroelectronics Ltd

   This program is free software; you can redistribute it and/or modify it
   under the terms and conditions of the GNU General Public License,
   version 2, as published by the Free Software Foundation.

   This program is distributed in the hope it will be useful, but WITHOUT
   ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
   more details.

   You should have received a copy of the GNU General Public License along with
   this program; if not, write to the Free Software Foundation, Inc.,
   51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.

   The full GNU General Public License is included in this distribution in
   the file called "COPYING".

   Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
 *******************************************************************************/

 #include <linux/stmmac.h>
 #include "common.h"
 #include "descs_com.h"

 static int enh_desc_get_tx_status(void *data, struct stmmac_extra_stats *x,
 				  struct dma_desc *p, void __iomem *ioaddr)
 {
 	struct net_device_stats *stats = (struct net_device_stats *)data;
 	unsigned int tdes0 = p->des0;
 	int ret = 0;

 	if (unlikely(tdes0 & ETDES0_ERROR_SUMMARY)) {
 		if (unlikely(tdes0 & ETDES0_JABBER_TIMEOUT))
 			x->tx_jabber++;

 		if (unlikely(tdes0 & ETDES0_FRAME_FLUSHED)) {
 			x->tx_frame_flushed++;
 			dwmac_dma_flush_tx_fifo(ioaddr);
 		}

 		if (unlikely(tdes0 & ETDES0_LOSS_CARRIER)) {
 			x->tx_losscarrier++;
 			stats->tx_carrier_errors++;
 		}
 		if (unlikely(tdes0 & ETDES0_NO_CARRIER)) {
 			x->tx_carrier++;
 			stats->tx_carrier_errors++;
 		}
 		if (unlikely((tdes0 & ETDES0_LATE_COLLISION) ||
 			     (tdes0 & ETDES0_EXCESSIVE_COLLISIONS)))
 			stats->collisions +=
 				(tdes0 & ETDES0_COLLISION_COUNT_MASK) >> 3;

 		if (unlikely(tdes0 & ETDES0_EXCESSIVE_DEFERRAL))
 			x->tx_deferred++;

 		if (unlikely(tdes0 & ETDES0_UNDERFLOW_ERROR)) {
 			dwmac_dma_flush_tx_fifo(ioaddr);
 			x->tx_underflow++;
 		}

 		if (unlikely(tdes0 & ETDES0_IP_HEADER_ERROR))
 			x->tx_ip_header_error++;

 		if (unlikely(tdes0 & ETDES0_PAYLOAD_ERROR)) {
 			x->tx_payload_error++;
 			dwmac_dma_flush_tx_fifo(ioaddr);
 		}

 		ret = -1;
 	}

 	if (unlikely(tdes0 & ETDES0_DEFERRED))
 		x->tx_deferred++;

 #ifdef STMMAC_VLAN_TAG_USED
 	if (tdes0 & ETDES0_VLAN_FRAME)
 		x->tx_vlan++;
 #endif

 	return ret;
 }

 static int enh_desc_get_tx_len(struct dma_desc *p)
 {
 	return (p->des1 & ETDES1_BUFFER1_SIZE_MASK);
 }

 static int enh_desc_coe_rdes0(int ipc_err, int type, int payload_err)
 {
 	int ret = good_frame;
 	u32 status = (type << 2 | ipc_err << 1 | payload_err) & 0x7;

 	/* bits 5 7 0 | Frame status
 	 * ----------------------------------------------------------
 	 *      0 0 0 | IEEE 802.3 Type frame (length < 1536 octects)
 	 *      1 0 0 | IPv4/6 No CSUM errorS.
 	 *      1 0 1 | IPv4/6 CSUM PAYLOAD error
 	 *      1 1 0 | IPv4/6 CSUM IP HR error
 	 *      1 1 1 | IPv4/6 IP PAYLOAD AND HEADER errorS
 	 *      0 0 1 | IPv4/6 unsupported IP PAYLOAD
 	 *      0 1 1 | COE bypassed.. no IPv4/6 frame
 	 *      0 1 0 | Reserved.
 	 */
 	if (status == 0x0)
 		ret = llc_snap;
 	else if (status == 0x4)
 		ret = good_frame;
 	else if (status == 0x5)
 		ret = csum_none;
 	else if (status == 0x6)
 		ret = csum_none;
 	else if (status == 0x7)
 		ret = csum_none;
 	else if (status == 0x1)
 		ret = discard_frame;
 	else if (status == 0x3)
 		ret = discard_frame;
 	return ret;
 }

 static void enh_desc_get_ext_status(void *data, struct stmmac_extra_stats *x,
 				    struct dma_extended_desc *p)
 {
 	unsigned int rdes0 = p->basic.des0;
 	unsigned int rdes4 = p->des4;

 	if (unlikely(rdes0 & ERDES0_RX_MAC_ADDR)) {
 		int message_type = (rdes4 & ERDES4_MSG_TYPE_MASK) >> 8;

 		if (rdes4 & ERDES4_IP_HDR_ERR)
 			x->ip_hdr_err++;
 		if (rdes4 & ERDES4_IP_PAYLOAD_ERR)
 			x->ip_payload_err++;
 		if (rdes4 & ERDES4_IP_CSUM_BYPASSED)
 			x->ip_csum_bypassed++;
 		if (rdes4 & ERDES4_IPV4_PKT_RCVD)
 			x->ipv4_pkt_rcvd++;
 		if (rdes4 & ERDES4_IPV6_PKT_RCVD)
 			x->ipv6_pkt_rcvd++;
 		if (message_type == RDES_EXT_SYNC)
 			x->rx_msg_type_sync++;
 		else if (message_type == RDES_EXT_FOLLOW_UP)
 			x->rx_msg_type_follow_up++;
 		else if (message_type == RDES_EXT_DELAY_REQ)
 			x->rx_msg_type_delay_req++;
 		else if (message_type == RDES_EXT_DELAY_RESP)
 			x->rx_msg_type_delay_resp++;
 		else if (message_type == RDES_EXT_PDELAY_REQ)
 			x->rx_msg_type_pdelay_req++;
 		else if (message_type == RDES_EXT_PDELAY_RESP)
 			x->rx_msg_type_pdelay_resp++;
 		else if (message_type == RDES_EXT_PDELAY_FOLLOW_UP)
 			x->rx_msg_type_pdelay_follow_up++;
 		else
 			x->rx_msg_type_ext_no_ptp++;
 		if (rdes4 & ERDES4_PTP_FRAME_TYPE)
 			x->ptp_frame_type++;
 		if (rdes4 & ERDES4_PTP_VER)
 			x->ptp_ver++;
 		if (rdes4 & ERDES4_TIMESTAMP_DROPPED)
 			x->timestamp_dropped++;
 		if (rdes4 & ERDES4_AV_PKT_RCVD)
 			x->av_pkt_rcvd++;
 		if (rdes4 & ERDES4_AV_TAGGED_PKT_RCVD)
 			x->av_tagged_pkt_rcvd++;
 		if ((rdes4 & ERDES4_VLAN_TAG_PRI_VAL_MASK) >> 18)
 			x->vlan_tag_priority_val++;
 		if (rdes4 & ERDES4_L3_FILTER_MATCH)
 			x->l3_filter_match++;
 		if (rdes4 & ERDES4_L4_FILTER_MATCH)
 			x->l4_filter_match++;
 		if ((rdes4 & ERDES4_L3_L4_FILT_NO_MATCH_MASK) >> 26)
 			x->l3_l4_filter_no_match++;
 	}
 }

 static int enh_desc_get_rx_status(void *data, struct stmmac_extra_stats *x,
 				  struct dma_desc *p)
 {
 	struct net_device_stats *stats = (struct net_device_stats *)data;
 	unsigned int rdes0 = p->des0;
 	int ret = good_frame;

 	if (unlikely(rdes0 & RDES0_OWN))
 		return dma_own;

 	if (unlikely(rdes0 & RDES0_ERROR_SUMMARY)) {
 		if (unlikely(rdes0 & RDES0_DESCRIPTOR_ERROR)) {
 			x->rx_desc++;
 			stats->rx_length_errors++;
 		}
 		if (unlikely(rdes0 & RDES0_OVERFLOW_ERROR))
 			x->rx_gmac_overflow++;

 		if (unlikely(rdes0 & RDES0_IPC_CSUM_ERROR))
 			pr_err("\tIPC Csum Error/Giant frame\n");

 		if (unlikely(rdes0 & RDES0_COLLISION))
 			stats->collisions++;
 		if (unlikely(rdes0 & RDES0_RECEIVE_WATCHDOG))
 			x->rx_watchdog++;

 		if (unlikely(rdes0 & RDES0_MII_ERROR))	/* GMII */
 			x->rx_mii++;

 		if (unlikely(rdes0 & RDES0_CRC_ERROR)) {
 			x->rx_crc++;
 			stats->rx_crc_errors++;
 		}
 		ret = discard_frame;
 	}

 	/* After a payload csum error, the ES bit is set.
 	 * It doesn't match with the information reported into the databook.
 	 * At any rate, we need to understand if the CSUM hw computation is ok
 	 * and report this info to the upper layers. */
 	ret = enh_desc_coe_rdes0(!!(rdes0 & RDES0_IPC_CSUM_ERROR),
 				 !!(rdes0 & RDES0_FRAME_TYPE),
 				 !!(rdes0 & ERDES0_RX_MAC_ADDR));

 	if (unlikely(rdes0 & RDES0_DRIBBLING))
 		x->dribbling_bit++;

 	if (unlikely(rdes0 & RDES0_SA_FILTER_FAIL)) {
 		x->sa_rx_filter_fail++;
 		ret = discard_frame;
 	}
 	if (unlikely(rdes0 & RDES0_DA_FILTER_FAIL)) {
 		x->da_rx_filter_fail++;
 		ret = discard_frame;
 	}
 	if (unlikely(rdes0 & RDES0_LENGTH_ERROR)) {
 		x->rx_length++;
 		ret = discard_frame;
 	}
 #ifdef STMMAC_VLAN_TAG_USED
 	if (rdes0 & RDES0_VLAN_TAG)
 		x->rx_vlan++;
 #endif

 	return ret;
 }

 static void enh_desc_init_rx_desc(struct dma_desc *p, int disable_rx_ic,
 				  int mode, int end)
 {
 	p->des0 |= RDES0_OWN;
 	p->des1 |= ((BUF_SIZE_8KiB - 1) & ERDES1_BUFFER1_SIZE_MASK);

 	if (mode == STMMAC_CHAIN_MODE)
 		ehn_desc_rx_set_on_chain(p);
 	else
 		ehn_desc_rx_set_on_ring(p, end);

 	if (disable_rx_ic)
 		p->des1 |= ERDES1_DISABLE_IC;
 }

 static void enh_desc_init_tx_desc(struct dma_desc *p, int mode, int end)
 {
 	p->des0 &= ~ETDES0_OWN;
 	if (mode == STMMAC_CHAIN_MODE)
 		enh_desc_end_tx_desc_on_chain(p);
 	else
 		enh_desc_end_tx_desc_on_ring(p, end);
 }

 static int enh_desc_get_tx_owner(struct dma_desc *p)
 {
 	return (p->des0 & ETDES0_OWN) >> 31;
 }

 static void enh_desc_set_tx_owner(struct dma_desc *p)
 {
 	p->des0 |= ETDES0_OWN;
 }

 static void enh_desc_set_rx_owner(struct dma_desc *p)
 {
 	p->des0 |= RDES0_OWN;
 }

 static int enh_desc_get_tx_ls(struct dma_desc *p)
 {
 	return (p->des0 & ETDES0_LAST_SEGMENT) >> 29;
 }

 static void enh_desc_release_tx_desc(struct dma_desc *p, int mode)
 {
 	int ter = (p->des0 & ETDES0_END_RING) >> 21;

 	memset(p, 0, offsetof(struct dma_desc, des2));
 	if (mode == STMMAC_CHAIN_MODE)
 		enh_desc_end_tx_desc_on_chain(p);
 	else
 		enh_desc_end_tx_desc_on_ring(p, ter);
 }

 static void enh_desc_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
 				     bool csum_flag, int mode, bool tx_own,
 				     bool ls_ic)
 {
 	unsigned int tdes0 = p->des0;

 	if (is_fs)
 		tdes0 |= ETDES0_FIRST_SEGMENT;
 	else
 		tdes0 &= ~ETDES0_FIRST_SEGMENT;

 	if (likely(csum_flag))
 		tdes0 |= (TX_CIC_FULL << ETDES0_CHECKSUM_INSERTION_SHIFT);
 	else
 		tdes0 &= ~(TX_CIC_FULL << ETDES0_CHECKSUM_INSERTION_SHIFT);

 	if (tx_own)
 		tdes0 |= ETDES0_OWN;

 	if (is_fs & tx_own)
 		/* When the own bit, for the first frame, has to be set, all
 		 * descriptors for the same frame has to be set before, to
 		 * avoid race condition.
 		 */
 		wmb();

 	if (ls_ic)
 		tdes0 |= ETDES0_LAST_SEGMENT | ETDES0_INTERRUPT;

 	p->des0 = tdes0;

 	if (mode == STMMAC_CHAIN_MODE)
 		enh_set_tx_desc_len_on_chain(p, len);
 	else
 		enh_set_tx_desc_len_on_ring(p, len);
 }

 static void enh_desc_clear_tx_ic(struct dma_desc *p)
 {
 	p->des0 &= ~ETDES0_INTERRUPT;
 }

 static int enh_desc_get_rx_frame_len(struct dma_desc *p, int rx_coe_type)
 {
 	unsigned int csum = 0;
 	/* The type-1 checksum offload engines append the checksum at
 	 * the end of frame and the two bytes of checksum are added in
 	 * the length.
 	 * Adjust for that in the framelen for type-1 checksum offload
 	 * engines.
 	 */
 	if (rx_coe_type == STMMAC_RX_COE_TYPE1)
 		csum = 2;

 	return (((p->des0 & RDES0_FRAME_LEN_MASK) >> RDES0_FRAME_LEN_SHIFT) -
 		csum);
 }

 static void enh_desc_enable_tx_timestamp(struct dma_desc *p)
 {
 	p->des0 |= ETDES0_TIME_STAMP_ENABLE;
 }

 static int enh_desc_get_tx_timestamp_status(struct dma_desc *p)
 {
 	return (p->des0 & ETDES0_TIME_STAMP_STATUS) >> 17;
 }

 static u64 enh_desc_get_timestamp(void *desc, u32 ats)
 {
 	u64 ns;

 	if (ats) {
 		struct dma_extended_desc *p = (struct dma_extended_desc *)desc;
 		ns = p->des6;
 		/* convert high/sec time stamp value to nanosecond */
 		ns += p->des7 * 1000000000ULL;
 	} else {
 		struct dma_desc *p = (struct dma_desc *)desc;
 		ns = p->des2;
 		ns += p->des3 * 1000000000ULL;
 	}

 	return ns;
 }

 static int enh_desc_get_rx_timestamp_status(void *desc, u32 ats)
 {
 	if (ats) {
 		struct dma_extended_desc *p = (struct dma_extended_desc *)desc;
 		return (p->basic.des0 & RDES0_IPC_CSUM_ERROR) >> 7;
 	} else {
 		struct dma_desc *p = (struct dma_desc *)desc;
 		if ((p->des2 == 0xffffffff) && (p->des3 == 0xffffffff))
 			/* timestamp is corrupted, hence don't store it */
 			return 0;
 		else
 			return 1;
 	}
 }

 const struct stmmac_desc_ops enh_desc_ops = {
 	.tx_status = enh_desc_get_tx_status,
 	.rx_status = enh_desc_get_rx_status,
 	.get_tx_len = enh_desc_get_tx_len,
 	.init_rx_desc = enh_desc_init_rx_desc,
 	.init_tx_desc = enh_desc_init_tx_desc,
 	.get_tx_owner = enh_desc_get_tx_owner,
 	.release_tx_desc = enh_desc_release_tx_desc,
 	.prepare_tx_desc = enh_desc_prepare_tx_desc,
 	.clear_tx_ic = enh_desc_clear_tx_ic,
 	.get_tx_ls = enh_desc_get_tx_ls,
 	.set_tx_owner = enh_desc_set_tx_owner,
 	.set_rx_owner = enh_desc_set_rx_owner,
 	.get_rx_frame_len = enh_desc_get_rx_frame_len,
 	.rx_extended_status = enh_desc_get_ext_status,
 	.enable_tx_timestamp = enh_desc_enable_tx_timestamp,
 	.get_tx_timestamp_status = enh_desc_get_tx_timestamp_status,
 	.get_timestamp = enh_desc_get_timestamp,
 	.get_rx_timestamp_status = enh_desc_get_rx_timestamp_status,
 };
	/*******************************************************************************
	This contains the functions to handle the enhanced descriptors.

	Copyright (C) 2007-2014 STMicroelectronics Ltd

	This program is free software; you can redistribute it and/or modify it
	under the terms and conditions of the GNU General Public License,
	version 2, as published by the Free Software Foundation.

	This program is distributed in the hope it will be useful, but WITHOUT
	ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	more details.

	You should have received a copy of the GNU General Public License along with
	this program; if not, write to the Free Software Foundation, Inc.,
	51 Franklin St - Fifth Floor, Boston, MA 02110-1301 USA.

	The full GNU General Public License is included in this distribution in
	the file called "COPYING".

	Author: Giuseppe Cavallaro <peppe.cavallaro@st.com>
	*******************************************************************************/

	#include <linux/stmmac.h>
	#include "common.h"
	#include "descs_com.h"

	static int enh_desc_get_tx_status(void data, struct stmmac_extra_stats x,
	struct dma_desc p, void __iomem ioaddr)
	{
	struct net_device_stats stats = (struct net_device_stats )data;
	unsigned int tdes0 = p->des0;
	int ret = 0;

	if (unlikely(tdes0 & ETDES0_ERROR_SUMMARY)) {
	if (unlikely(tdes0 & ETDES0_JABBER_TIMEOUT))
	x->tx_jabber++;

	if (unlikely(tdes0 & ETDES0_FRAME_FLUSHED)) {
	x->tx_frame_flushed++;
	dwmac_dma_flush_tx_fifo(ioaddr);
	}

	if (unlikely(tdes0 & ETDES0_LOSS_CARRIER)) {
	x->tx_losscarrier++;
	stats->tx_carrier_errors++;
	}
	if (unlikely(tdes0 & ETDES0_NO_CARRIER)) {
	x->tx_carrier++;
	stats->tx_carrier_errors++;
	}
	if (unlikely((tdes0 & ETDES0_LATE_COLLISION) \|\|
	(tdes0 & ETDES0_EXCESSIVE_COLLISIONS)))
	stats->collisions +=
	(tdes0 & ETDES0_COLLISION_COUNT_MASK) >> 3;

	if (unlikely(tdes0 & ETDES0_EXCESSIVE_DEFERRAL))
	x->tx_deferred++;

	if (unlikely(tdes0 & ETDES0_UNDERFLOW_ERROR)) {
	dwmac_dma_flush_tx_fifo(ioaddr);
	x->tx_underflow++;
	}

	if (unlikely(tdes0 & ETDES0_IP_HEADER_ERROR))
	x->tx_ip_header_error++;

	if (unlikely(tdes0 & ETDES0_PAYLOAD_ERROR)) {
	x->tx_payload_error++;
	dwmac_dma_flush_tx_fifo(ioaddr);
	}

	ret = -1;
	}

	if (unlikely(tdes0 & ETDES0_DEFERRED))
	x->tx_deferred++;

	#ifdef STMMAC_VLAN_TAG_USED
	if (tdes0 & ETDES0_VLAN_FRAME)
	x->tx_vlan++;
	#endif

	return ret;
	}

	static int enh_desc_get_tx_len(struct dma_desc *p)
	{
	return (p->des1 & ETDES1_BUFFER1_SIZE_MASK);
	}

	static int enh_desc_coe_rdes0(int ipc_err, int type, int payload_err)
	{
	int ret = good_frame;
	u32 status = (type << 2 \| ipc_err << 1 \| payload_err) & 0x7;

	/* bits 5 7 0 \| Frame status
	* ----------------------------------------------------------
	* 0 0 0 \| IEEE 802.3 Type frame (length < 1536 octects)
	* 1 0 0 \| IPv4/6 No CSUM errorS.
	* 1 0 1 \| IPv4/6 CSUM PAYLOAD error
	* 1 1 0 \| IPv4/6 CSUM IP HR error
	* 1 1 1 \| IPv4/6 IP PAYLOAD AND HEADER errorS
	* 0 0 1 \| IPv4/6 unsupported IP PAYLOAD
	* 0 1 1 \| COE bypassed.. no IPv4/6 frame
	* 0 1 0 \| Reserved.
	*/
	if (status == 0x0)
	ret = llc_snap;
	else if (status == 0x4)
	ret = good_frame;
	else if (status == 0x5)
	ret = csum_none;
	else if (status == 0x6)
	ret = csum_none;
	else if (status == 0x7)
	ret = csum_none;
	else if (status == 0x1)
	ret = discard_frame;
	else if (status == 0x3)
	ret = discard_frame;
	return ret;
	}

	static void enh_desc_get_ext_status(void data, struct stmmac_extra_stats x,
	struct dma_extended_desc *p)
	{
	unsigned int rdes0 = p->basic.des0;
	unsigned int rdes4 = p->des4;

	if (unlikely(rdes0 & ERDES0_RX_MAC_ADDR)) {
	int message_type = (rdes4 & ERDES4_MSG_TYPE_MASK) >> 8;

	if (rdes4 & ERDES4_IP_HDR_ERR)
	x->ip_hdr_err++;
	if (rdes4 & ERDES4_IP_PAYLOAD_ERR)
	x->ip_payload_err++;
	if (rdes4 & ERDES4_IP_CSUM_BYPASSED)
	x->ip_csum_bypassed++;
	if (rdes4 & ERDES4_IPV4_PKT_RCVD)
	x->ipv4_pkt_rcvd++;
	if (rdes4 & ERDES4_IPV6_PKT_RCVD)
	x->ipv6_pkt_rcvd++;
	if (message_type == RDES_EXT_SYNC)
	x->rx_msg_type_sync++;
	else if (message_type == RDES_EXT_FOLLOW_UP)
	x->rx_msg_type_follow_up++;
	else if (message_type == RDES_EXT_DELAY_REQ)
	x->rx_msg_type_delay_req++;
	else if (message_type == RDES_EXT_DELAY_RESP)
	x->rx_msg_type_delay_resp++;
	else if (message_type == RDES_EXT_PDELAY_REQ)
	x->rx_msg_type_pdelay_req++;
	else if (message_type == RDES_EXT_PDELAY_RESP)
	x->rx_msg_type_pdelay_resp++;
	else if (message_type == RDES_EXT_PDELAY_FOLLOW_UP)
	x->rx_msg_type_pdelay_follow_up++;
	else
	x->rx_msg_type_ext_no_ptp++;
	if (rdes4 & ERDES4_PTP_FRAME_TYPE)
	x->ptp_frame_type++;
	if (rdes4 & ERDES4_PTP_VER)
	x->ptp_ver++;
	if (rdes4 & ERDES4_TIMESTAMP_DROPPED)
	x->timestamp_dropped++;
	if (rdes4 & ERDES4_AV_PKT_RCVD)
	x->av_pkt_rcvd++;
	if (rdes4 & ERDES4_AV_TAGGED_PKT_RCVD)
	x->av_tagged_pkt_rcvd++;
	if ((rdes4 & ERDES4_VLAN_TAG_PRI_VAL_MASK) >> 18)
	x->vlan_tag_priority_val++;
	if (rdes4 & ERDES4_L3_FILTER_MATCH)
	x->l3_filter_match++;
	if (rdes4 & ERDES4_L4_FILTER_MATCH)
	x->l4_filter_match++;
	if ((rdes4 & ERDES4_L3_L4_FILT_NO_MATCH_MASK) >> 26)
	x->l3_l4_filter_no_match++;
	}
	}

	static int enh_desc_get_rx_status(void data, struct stmmac_extra_stats x,
	struct dma_desc *p)
	{
	struct net_device_stats stats = (struct net_device_stats )data;
	unsigned int rdes0 = p->des0;
	int ret = good_frame;

	if (unlikely(rdes0 & RDES0_OWN))
	return dma_own;

	if (unlikely(rdes0 & RDES0_ERROR_SUMMARY)) {
	if (unlikely(rdes0 & RDES0_DESCRIPTOR_ERROR)) {
	x->rx_desc++;
	stats->rx_length_errors++;
	}
	if (unlikely(rdes0 & RDES0_OVERFLOW_ERROR))
	x->rx_gmac_overflow++;

	if (unlikely(rdes0 & RDES0_IPC_CSUM_ERROR))
	pr_err("\tIPC Csum Error/Giant frame\n");

	if (unlikely(rdes0 & RDES0_COLLISION))
	stats->collisions++;
	if (unlikely(rdes0 & RDES0_RECEIVE_WATCHDOG))
	x->rx_watchdog++;

	if (unlikely(rdes0 & RDES0_MII_ERROR)) /* GMII */
	x->rx_mii++;

	if (unlikely(rdes0 & RDES0_CRC_ERROR)) {
	x->rx_crc++;
	stats->rx_crc_errors++;
	}
	ret = discard_frame;
	}

	/* After a payload csum error, the ES bit is set.
	* It doesn't match with the information reported into the databook.
	* At any rate, we need to understand if the CSUM hw computation is ok
	* and report this info to the upper layers. */
	ret = enh_desc_coe_rdes0(!!(rdes0 & RDES0_IPC_CSUM_ERROR),
	!!(rdes0 & RDES0_FRAME_TYPE),
	!!(rdes0 & ERDES0_RX_MAC_ADDR));

	if (unlikely(rdes0 & RDES0_DRIBBLING))
	x->dribbling_bit++;

	if (unlikely(rdes0 & RDES0_SA_FILTER_FAIL)) {
	x->sa_rx_filter_fail++;
	ret = discard_frame;
	}
	if (unlikely(rdes0 & RDES0_DA_FILTER_FAIL)) {
	x->da_rx_filter_fail++;
	ret = discard_frame;
	}
	if (unlikely(rdes0 & RDES0_LENGTH_ERROR)) {
	x->rx_length++;
	ret = discard_frame;
	}
	#ifdef STMMAC_VLAN_TAG_USED
	if (rdes0 & RDES0_VLAN_TAG)
	x->rx_vlan++;
	#endif

	return ret;
	}

	static void enh_desc_init_rx_desc(struct dma_desc *p, int disable_rx_ic,
	int mode, int end)
	{
	p->des0 \|= RDES0_OWN;
	p->des1 \|= ((BUF_SIZE_8KiB - 1) & ERDES1_BUFFER1_SIZE_MASK);

	if (mode == STMMAC_CHAIN_MODE)
	ehn_desc_rx_set_on_chain(p);
	else
	ehn_desc_rx_set_on_ring(p, end);

	if (disable_rx_ic)
	p->des1 \|= ERDES1_DISABLE_IC;
	}

	static void enh_desc_init_tx_desc(struct dma_desc *p, int mode, int end)
	{
	p->des0 &= ~ETDES0_OWN;
	if (mode == STMMAC_CHAIN_MODE)
	enh_desc_end_tx_desc_on_chain(p);
	else
	enh_desc_end_tx_desc_on_ring(p, end);
	}

	static int enh_desc_get_tx_owner(struct dma_desc *p)
	{
	return (p->des0 & ETDES0_OWN) >> 31;
	}

	static void enh_desc_set_tx_owner(struct dma_desc *p)
	{
	p->des0 \|= ETDES0_OWN;
	}

	static void enh_desc_set_rx_owner(struct dma_desc *p)
	{
	p->des0 \|= RDES0_OWN;
	}

	static int enh_desc_get_tx_ls(struct dma_desc *p)
	{
	return (p->des0 & ETDES0_LAST_SEGMENT) >> 29;
	}

	static void enh_desc_release_tx_desc(struct dma_desc *p, int mode)
	{
	int ter = (p->des0 & ETDES0_END_RING) >> 21;

	memset(p, 0, offsetof(struct dma_desc, des2));
	if (mode == STMMAC_CHAIN_MODE)
	enh_desc_end_tx_desc_on_chain(p);
	else
	enh_desc_end_tx_desc_on_ring(p, ter);
	}

	static void enh_desc_prepare_tx_desc(struct dma_desc *p, int is_fs, int len,
	bool csum_flag, int mode, bool tx_own,
	bool ls_ic)
	{
	unsigned int tdes0 = p->des0;

	if (is_fs)
	tdes0 \|= ETDES0_FIRST_SEGMENT;
	else
	tdes0 &= ~ETDES0_FIRST_SEGMENT;

	if (likely(csum_flag))
	tdes0 \|= (TX_CIC_FULL << ETDES0_CHECKSUM_INSERTION_SHIFT);
	else
	tdes0 &= ~(TX_CIC_FULL << ETDES0_CHECKSUM_INSERTION_SHIFT);

	if (tx_own)
	tdes0 \|= ETDES0_OWN;

	if (is_fs & tx_own)
	/* When the own bit, for the first frame, has to be set, all
	* descriptors for the same frame has to be set before, to
	* avoid race condition.
	*/
	wmb();

	if (ls_ic)
	tdes0 \|= ETDES0_LAST_SEGMENT \| ETDES0_INTERRUPT;

	p->des0 = tdes0;

	if (mode == STMMAC_CHAIN_MODE)
	enh_set_tx_desc_len_on_chain(p, len);
	else
	enh_set_tx_desc_len_on_ring(p, len);
	}

	static void enh_desc_clear_tx_ic(struct dma_desc *p)
	{
	p->des0 &= ~ETDES0_INTERRUPT;
	}

	static int enh_desc_get_rx_frame_len(struct dma_desc *p, int rx_coe_type)
	{
	unsigned int csum = 0;
	/* The type-1 checksum offload engines append the checksum at
	* the end of frame and the two bytes of checksum are added in
	* the length.
	* Adjust for that in the framelen for type-1 checksum offload
	* engines.
	*/
	if (rx_coe_type == STMMAC_RX_COE_TYPE1)
	csum = 2;

	return (((p->des0 & RDES0_FRAME_LEN_MASK) >> RDES0_FRAME_LEN_SHIFT) -
	csum);
	}

	static void enh_desc_enable_tx_timestamp(struct dma_desc *p)
	{
	p->des0 \|= ETDES0_TIME_STAMP_ENABLE;
	}

	static int enh_desc_get_tx_timestamp_status(struct dma_desc *p)
	{
	return (p->des0 & ETDES0_TIME_STAMP_STATUS) >> 17;
	}

	static u64 enh_desc_get_timestamp(void *desc, u32 ats)
	{
	u64 ns;

	if (ats) {
	struct dma_extended_desc p = (struct dma_extended_desc )desc;
	ns = p->des6;
	/* convert high/sec time stamp value to nanosecond */
	ns += p->des7 * 1000000000ULL;
	} else {
	struct dma_desc p = (struct dma_desc )desc;
	ns = p->des2;
	ns += p->des3 * 1000000000ULL;
	}

	return ns;
	}

	static int enh_desc_get_rx_timestamp_status(void *desc, u32 ats)
	{
	if (ats) {
	struct dma_extended_desc p = (struct dma_extended_desc )desc;
	return (p->basic.des0 & RDES0_IPC_CSUM_ERROR) >> 7;
	} else {
	struct dma_desc p = (struct dma_desc )desc;
	if ((p->des2 == 0xffffffff) && (p->des3 == 0xffffffff))
	/* timestamp is corrupted, hence don't store it */
	return 0;
	else
	return 1;
	}
	}

	const struct stmmac_desc_ops enh_desc_ops = {
	.tx_status = enh_desc_get_tx_status,
	.rx_status = enh_desc_get_rx_status,
	.get_tx_len = enh_desc_get_tx_len,
	.init_rx_desc = enh_desc_init_rx_desc,
	.init_tx_desc = enh_desc_init_tx_desc,
	.get_tx_owner = enh_desc_get_tx_owner,
	.release_tx_desc = enh_desc_release_tx_desc,
	.prepare_tx_desc = enh_desc_prepare_tx_desc,
	.clear_tx_ic = enh_desc_clear_tx_ic,
	.get_tx_ls = enh_desc_get_tx_ls,
	.set_tx_owner = enh_desc_set_tx_owner,
	.set_rx_owner = enh_desc_set_rx_owner,
	.get_rx_frame_len = enh_desc_get_rx_frame_len,
	.rx_extended_status = enh_desc_get_ext_status,
	.enable_tx_timestamp = enh_desc_enable_tx_timestamp,
	.get_tx_timestamp_status = enh_desc_get_tx_timestamp_status,
	.get_timestamp = enh_desc_get_timestamp,
	.get_rx_timestamp_status = enh_desc_get_rx_timestamp_status,
	};