xgmac.c

/*
 * Copyright 2010-2011 Calxeda, Inc.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 */
#include <linux/module.h>
#include <linux/init.h>
#include <linux/kernel.h>
#include <linux/circ_buf.h>
#include <linux/interrupt.h>
#include <linux/etherdevice.h>
#include <linux/platform_device.h>
#include <linux/skbuff.h>
#include <linux/ethtool.h>
#include <linux/if.h>
#include <linux/crc32.h>
#include <linux/dma-mapping.h>
#include <linux/slab.h>

/* XGMAC Register definitions */
#define XGMAC_CONTROL		0x00000000	/* MAC Configuration */
#define XGMAC_FRAME_FILTER	0x00000004	/* MAC Frame Filter */
#define XGMAC_FLOW_CTRL		0x00000018	/* MAC Flow Control */
#define XGMAC_VLAN_TAG		0x0000001C	/* VLAN Tags */
#define XGMAC_VERSION		0x00000020	/* Version */
#define XGMAC_VLAN_INCL		0x00000024	/* VLAN tag for tx frames */
#define XGMAC_LPI_CTRL		0x00000028	/* LPI Control and Status */
#define XGMAC_LPI_TIMER		0x0000002C	/* LPI Timers Control */
#define XGMAC_TX_PACE		0x00000030	/* Transmit Pace and Stretch */
#define XGMAC_VLAN_HASH		0x00000034	/* VLAN Hash Table */
#define XGMAC_DEBUG		0x00000038	/* Debug */
#define XGMAC_INT_STAT		0x0000003C	/* Interrupt and Control */
#define XGMAC_ADDR_HIGH(reg)	(0x00000040 + ((reg) * 8))
#define XGMAC_ADDR_LOW(reg)	(0x00000044 + ((reg) * 8))
#define XGMAC_HASH(n)		(0x00000300 + (n) * 4) /* HASH table regs */
#define XGMAC_NUM_HASH		16
#define XGMAC_OMR		0x00000400
#define XGMAC_REMOTE_WAKE	0x00000700	/* Remote Wake-Up Frm Filter */
#define XGMAC_PMT		0x00000704	/* PMT Control and Status */
#define XGMAC_MMC_CTRL		0x00000800	/* XGMAC MMC Control */
#define XGMAC_MMC_INTR_RX	0x00000804	/* Recieve Interrupt */
#define XGMAC_MMC_INTR_TX	0x00000808	/* Transmit Interrupt */
#define XGMAC_MMC_INTR_MASK_RX	0x0000080c	/* Recieve Interrupt Mask */
#define XGMAC_MMC_INTR_MASK_TX	0x00000810	/* Transmit Interrupt Mask */

/* Hardware TX Statistics Counters */
#define XGMAC_MMC_TXOCTET_GB_LO	0x00000814
#define XGMAC_MMC_TXOCTET_GB_HI	0x00000818
#define XGMAC_MMC_TXFRAME_GB_LO	0x0000081C
#define XGMAC_MMC_TXFRAME_GB_HI	0x00000820
#define XGMAC_MMC_TXBCFRAME_G	0x00000824
#define XGMAC_MMC_TXMCFRAME_G	0x0000082C
#define XGMAC_MMC_TXUCFRAME_GB	0x00000864
#define XGMAC_MMC_TXMCFRAME_GB	0x0000086C
#define XGMAC_MMC_TXBCFRAME_GB	0x00000874
#define XGMAC_MMC_TXUNDERFLOW	0x0000087C
#define XGMAC_MMC_TXOCTET_G_LO	0x00000884
#define XGMAC_MMC_TXOCTET_G_HI	0x00000888
#define XGMAC_MMC_TXFRAME_G_LO	0x0000088C
#define XGMAC_MMC_TXFRAME_G_HI	0x00000890
#define XGMAC_MMC_TXPAUSEFRAME	0x00000894
#define XGMAC_MMC_TXVLANFRAME	0x0000089C

/* Hardware RX Statistics Counters */
#define XGMAC_MMC_RXFRAME_GB_LO	0x00000900
#define XGMAC_MMC_RXFRAME_GB_HI	0x00000904
#define XGMAC_MMC_RXOCTET_GB_LO	0x00000908
#define XGMAC_MMC_RXOCTET_GB_HI	0x0000090C
#define XGMAC_MMC_RXOCTET_G_LO	0x00000910
#define XGMAC_MMC_RXOCTET_G_HI	0x00000914
#define XGMAC_MMC_RXBCFRAME_G	0x00000918
#define XGMAC_MMC_RXMCFRAME_G	0x00000920
#define XGMAC_MMC_RXCRCERR	0x00000928
#define XGMAC_MMC_RXRUNT	0x00000930
#define XGMAC_MMC_RXJABBER	0x00000934
#define XGMAC_MMC_RXUCFRAME_G	0x00000970
#define XGMAC_MMC_RXLENGTHERR	0x00000978
#define XGMAC_MMC_RXPAUSEFRAME	0x00000988
#define XGMAC_MMC_RXOVERFLOW	0x00000990
#define XGMAC_MMC_RXVLANFRAME	0x00000998
#define XGMAC_MMC_RXWATCHDOG	0x000009a0

/* DMA Control and Status Registers */
#define XGMAC_DMA_BUS_MODE	0x00000f00	/* Bus Mode */
#define XGMAC_DMA_TX_POLL	0x00000f04	/* Transmit Poll Demand */
#define XGMAC_DMA_RX_POLL	0x00000f08	/* Received Poll Demand */
#define XGMAC_DMA_RX_BASE_ADDR	0x00000f0c	/* Receive List Base */
#define XGMAC_DMA_TX_BASE_ADDR	0x00000f10	/* Transmit List Base */
#define XGMAC_DMA_STATUS	0x00000f14	/* Status Register */
#define XGMAC_DMA_CONTROL	0x00000f18	/* Ctrl (Operational Mode) */
#define XGMAC_DMA_INTR_ENA	0x00000f1c	/* Interrupt Enable */
#define XGMAC_DMA_MISS_FRAME_CTR 0x00000f20	/* Missed Frame Counter */
#define XGMAC_DMA_RI_WDOG_TIMER	0x00000f24	/* RX Intr Watchdog Timer */
#define XGMAC_DMA_AXI_BUS	0x00000f28	/* AXI Bus Mode */
#define XGMAC_DMA_AXI_STATUS	0x00000f2C	/* AXI Status */
#define XGMAC_DMA_HW_FEATURE	0x00000f58	/* Enabled Hardware Features */

#define XGMAC_ADDR_AE		0x80000000
#define XGMAC_MAX_FILTER_ADDR	31

/* PMT Control and Status */
#define XGMAC_PMT_POINTER_RESET	0x80000000
#define XGMAC_PMT_GLBL_UNICAST	0x00000200
#define XGMAC_PMT_WAKEUP_RX_FRM	0x00000040
#define XGMAC_PMT_MAGIC_PKT	0x00000020
#define XGMAC_PMT_WAKEUP_FRM_EN	0x00000004
#define XGMAC_PMT_MAGIC_PKT_EN	0x00000002
#define XGMAC_PMT_POWERDOWN	0x00000001

#define XGMAC_CONTROL_SPD	0x40000000	/* Speed control */
#define XGMAC_CONTROL_SPD_MASK	0x60000000
#define XGMAC_CONTROL_SPD_1G	0x60000000
#define XGMAC_CONTROL_SPD_2_5G	0x40000000
#define XGMAC_CONTROL_SPD_10G	0x00000000
#define XGMAC_CONTROL_SARC	0x10000000	/* Source Addr Insert/Replace */
#define XGMAC_CONTROL_SARK_MASK	0x18000000
#define XGMAC_CONTROL_CAR	0x04000000	/* CRC Addition/Replacement */
#define XGMAC_CONTROL_CAR_MASK	0x06000000
#define XGMAC_CONTROL_DP	0x01000000	/* Disable Padding */
#define XGMAC_CONTROL_WD	0x00800000	/* Disable Watchdog on rx */
#define XGMAC_CONTROL_JD	0x00400000	/* Jabber disable */
#define XGMAC_CONTROL_JE	0x00100000	/* Jumbo frame */
#define XGMAC_CONTROL_LM	0x00001000	/* Loop-back mode */
#define XGMAC_CONTROL_IPC	0x00000400	/* Checksum Offload */
#define XGMAC_CONTROL_ACS	0x00000080	/* Automatic Pad/FCS Strip */
#define XGMAC_CONTROL_DDIC	0x00000010	/* Disable Deficit Idle Count */
#define XGMAC_CONTROL_TE	0x00000008	/* Transmitter Enable */
#define XGMAC_CONTROL_RE	0x00000004	/* Receiver Enable */

/* XGMAC Frame Filter defines */
#define XGMAC_FRAME_FILTER_PR	0x00000001	/* Promiscuous Mode */
#define XGMAC_FRAME_FILTER_HUC	0x00000002	/* Hash Unicast */
#define XGMAC_FRAME_FILTER_HMC	0x00000004	/* Hash Multicast */
#define XGMAC_FRAME_FILTER_DAIF	0x00000008	/* DA Inverse Filtering */
#define XGMAC_FRAME_FILTER_PM	0x00000010	/* Pass all multicast */
#define XGMAC_FRAME_FILTER_DBF	0x00000020	/* Disable Broadcast frames */
#define XGMAC_FRAME_FILTER_SAIF	0x00000100	/* Inverse Filtering */
#define XGMAC_FRAME_FILTER_SAF	0x00000200	/* Source Address Filter */
#define XGMAC_FRAME_FILTER_HPF	0x00000400	/* Hash or perfect Filter */
#define XGMAC_FRAME_FILTER_VHF	0x00000800	/* VLAN Hash Filter */
#define XGMAC_FRAME_FILTER_VPF	0x00001000	/* VLAN Perfect Filter */
#define XGMAC_FRAME_FILTER_RA	0x80000000	/* Receive all mode */

/* XGMAC FLOW CTRL defines */
#define XGMAC_FLOW_CTRL_PT_MASK	0xffff0000	/* Pause Time Mask */
#define XGMAC_FLOW_CTRL_PT_SHIFT	16
#define XGMAC_FLOW_CTRL_DZQP	0x00000080	/* Disable Zero-Quanta Phase */
#define XGMAC_FLOW_CTRL_PLT	0x00000020	/* Pause Low Threshhold */
#define XGMAC_FLOW_CTRL_PLT_MASK 0x00000030	/* PLT MASK */
#define XGMAC_FLOW_CTRL_UP	0x00000008	/* Unicast Pause Frame Detect */
#define XGMAC_FLOW_CTRL_RFE	0x00000004	/* Rx Flow Control Enable */
#define XGMAC_FLOW_CTRL_TFE	0x00000002	/* Tx Flow Control Enable */
#define XGMAC_FLOW_CTRL_FCB_BPA	0x00000001	/* Flow Control Busy ... */

/* XGMAC_INT_STAT reg */
#define XGMAC_INT_STAT_PMT	0x0080		/* PMT Interrupt Status */
#define XGMAC_INT_STAT_LPI	0x0040		/* LPI Interrupt Status */

/* DMA Bus Mode register defines */
#define DMA_BUS_MODE_SFT_RESET	0x00000001	/* Software Reset */
#define DMA_BUS_MODE_DSL_MASK	0x0000007c	/* Descriptor Skip Length */
#define DMA_BUS_MODE_DSL_SHIFT	2		/* (in DWORDS) */
#define DMA_BUS_MODE_ATDS	0x00000080	/* Alternate Descriptor Size */

/* Programmable burst length */
#define DMA_BUS_MODE_PBL_MASK	0x00003f00	/* Programmable Burst Len */
#define DMA_BUS_MODE_PBL_SHIFT	8
#define DMA_BUS_MODE_FB		0x00010000	/* Fixed burst */
#define DMA_BUS_MODE_RPBL_MASK	0x003e0000	/* Rx-Programmable Burst Len */
#define DMA_BUS_MODE_RPBL_SHIFT	17
#define DMA_BUS_MODE_USP	0x00800000
#define DMA_BUS_MODE_8PBL	0x01000000
#define DMA_BUS_MODE_AAL	0x02000000

/* DMA Bus Mode register defines */
#define DMA_BUS_PR_RATIO_MASK	0x0000c000	/* Rx/Tx priority ratio */
#define DMA_BUS_PR_RATIO_SHIFT	14
#define DMA_BUS_FB		0x00010000	/* Fixed Burst */

/* DMA Control register defines */
#define DMA_CONTROL_ST		0x00002000	/* Start/Stop Transmission */
#define DMA_CONTROL_SR		0x00000002	/* Start/Stop Receive */
#define DMA_CONTROL_DFF		0x01000000	/* Disable flush of rx frames */
#define DMA_CONTROL_OSF		0x00000004	/* Operate on 2nd tx frame */

/* DMA Normal interrupt */
#define DMA_INTR_ENA_NIE	0x00010000	/* Normal Summary */
#define DMA_INTR_ENA_AIE	0x00008000	/* Abnormal Summary */
#define DMA_INTR_ENA_ERE	0x00004000	/* Early Receive */
#define DMA_INTR_ENA_FBE	0x00002000	/* Fatal Bus Error */
#define DMA_INTR_ENA_ETE	0x00000400	/* Early Transmit */
#define DMA_INTR_ENA_RWE	0x00000200	/* Receive Watchdog */
#define DMA_INTR_ENA_RSE	0x00000100	/* Receive Stopped */
#define DMA_INTR_ENA_RUE	0x00000080	/* Receive Buffer Unavailable */
#define DMA_INTR_ENA_RIE	0x00000040	/* Receive Interrupt */
#define DMA_INTR_ENA_UNE	0x00000020	/* Tx Underflow */
#define DMA_INTR_ENA_OVE	0x00000010	/* Receive Overflow */
#define DMA_INTR_ENA_TJE	0x00000008	/* Transmit Jabber */
#define DMA_INTR_ENA_TUE	0x00000004	/* Transmit Buffer Unavail */
#define DMA_INTR_ENA_TSE	0x00000002	/* Transmit Stopped */
#define DMA_INTR_ENA_TIE	0x00000001	/* Transmit Interrupt */

#define DMA_INTR_NORMAL		(DMA_INTR_ENA_NIE | DMA_INTR_ENA_RIE | \
				 DMA_INTR_ENA_TUE)

#define DMA_INTR_ABNORMAL	(DMA_INTR_ENA_AIE | DMA_INTR_ENA_FBE | \
				 DMA_INTR_ENA_RWE | DMA_INTR_ENA_RSE | \
				 DMA_INTR_ENA_RUE | DMA_INTR_ENA_UNE | \
				 DMA_INTR_ENA_OVE | DMA_INTR_ENA_TJE | \
				 DMA_INTR_ENA_TSE)

/* DMA default interrupt mask */
#define DMA_INTR_DEFAULT_MASK	(DMA_INTR_NORMAL | DMA_INTR_ABNORMAL)

/* DMA Status register defines */
#define DMA_STATUS_GMI		0x08000000	/* MMC interrupt */
#define DMA_STATUS_GLI		0x04000000	/* GMAC Line interface int */
#define DMA_STATUS_EB_MASK	0x00380000	/* Error Bits Mask */
#define DMA_STATUS_EB_TX_ABORT	0x00080000	/* Error Bits - TX Abort */
#define DMA_STATUS_EB_RX_ABORT	0x00100000	/* Error Bits - RX Abort */
#define DMA_STATUS_TS_MASK	0x00700000	/* Transmit Process State */
#define DMA_STATUS_TS_SHIFT	20
#define DMA_STATUS_RS_MASK	0x000e0000	/* Receive Process State */
#define DMA_STATUS_RS_SHIFT	17
#define DMA_STATUS_NIS		0x00010000	/* Normal Interrupt Summary */
#define DMA_STATUS_AIS		0x00008000	/* Abnormal Interrupt Summary */
#define DMA_STATUS_ERI		0x00004000	/* Early Receive Interrupt */
#define DMA_STATUS_FBI		0x00002000	/* Fatal Bus Error Interrupt */
#define DMA_STATUS_ETI		0x00000400	/* Early Transmit Interrupt */
#define DMA_STATUS_RWT		0x00000200	/* Receive Watchdog Timeout */
#define DMA_STATUS_RPS		0x00000100	/* Receive Process Stopped */
#define DMA_STATUS_RU		0x00000080	/* Receive Buffer Unavailable */
#define DMA_STATUS_RI		0x00000040	/* Receive Interrupt */
#define DMA_STATUS_UNF		0x00000020	/* Transmit Underflow */
#define DMA_STATUS_OVF		0x00000010	/* Receive Overflow */
#define DMA_STATUS_TJT		0x00000008	/* Transmit Jabber Timeout */
#define DMA_STATUS_TU		0x00000004	/* Transmit Buffer Unavail */
#define DMA_STATUS_TPS		0x00000002	/* Transmit Process Stopped */
#define DMA_STATUS_TI		0x00000001	/* Transmit Interrupt */

/* Common MAC defines */
#define MAC_ENABLE_TX		0x00000008	/* Transmitter Enable */
#define MAC_ENABLE_RX		0x00000004	/* Receiver Enable */

/* XGMAC Operation Mode Register */
#define XGMAC_OMR_TSF		0x00200000	/* TX FIFO Store and Forward */
#define XGMAC_OMR_FTF		0x00100000	/* Flush Transmit FIFO */
#define XGMAC_OMR_TTC		0x00020000	/* Transmit Threshhold Ctrl */
#define XGMAC_OMR_TTC_MASK	0x00030000
#define XGMAC_OMR_RFD		0x00006000	/* FC Deactivation Threshhold */
#define XGMAC_OMR_RFD_MASK	0x00007000	/* FC Deact Threshhold MASK */
#define XGMAC_OMR_RFA		0x00000600	/* FC Activation Threshhold */
#define XGMAC_OMR_RFA_MASK	0x00000E00	/* FC Act Threshhold MASK */
#define XGMAC_OMR_EFC		0x00000100	/* Enable Hardware FC */
#define XGMAC_OMR_FEF		0x00000080	/* Forward Error Frames */
#define XGMAC_OMR_DT		0x00000040	/* Drop TCP/IP csum Errors */
#define XGMAC_OMR_RSF		0x00000020	/* RX FIFO Store and Forward */
#define XGMAC_OMR_RTC_256	0x00000018	/* RX Threshhold Ctrl */
#define XGMAC_OMR_RTC_MASK	0x00000018	/* RX Threshhold Ctrl MASK */

/* XGMAC HW Features Register */
#define DMA_HW_FEAT_TXCOESEL	0x00010000	/* TX Checksum offload */

#define XGMAC_MMC_CTRL_CNT_FRZ	0x00000008

/* XGMAC Descriptor Defines */
#define MAX_DESC_BUF_SZ		(0x2000 - 8)

#define RXDESC_EXT_STATUS	0x00000001
#define RXDESC_CRC_ERR		0x00000002
#define RXDESC_RX_ERR		0x00000008
#define RXDESC_RX_WDOG		0x00000010
#define RXDESC_FRAME_TYPE	0x00000020
#define RXDESC_GIANT_FRAME	0x00000080
#define RXDESC_LAST_SEG		0x00000100
#define RXDESC_FIRST_SEG	0x00000200
#define RXDESC_VLAN_FRAME	0x00000400
#define RXDESC_OVERFLOW_ERR	0x00000800
#define RXDESC_LENGTH_ERR	0x00001000
#define RXDESC_SA_FILTER_FAIL	0x00002000
#define RXDESC_DESCRIPTOR_ERR	0x00004000
#define RXDESC_ERROR_SUMMARY	0x00008000
#define RXDESC_FRAME_LEN_OFFSET	16
#define RXDESC_FRAME_LEN_MASK	0x3fff0000
#define RXDESC_DA_FILTER_FAIL	0x40000000

#define RXDESC1_END_RING	0x00008000

#define RXDESC_IP_PAYLOAD_MASK	0x00000003
#define RXDESC_IP_PAYLOAD_UDP	0x00000001
#define RXDESC_IP_PAYLOAD_TCP	0x00000002
#define RXDESC_IP_PAYLOAD_ICMP	0x00000003
#define RXDESC_IP_HEADER_ERR	0x00000008
#define RXDESC_IP_PAYLOAD_ERR	0x00000010
#define RXDESC_IPV4_PACKET	0x00000040
#define RXDESC_IPV6_PACKET	0x00000080
#define TXDESC_UNDERFLOW_ERR	0x00000001
#define TXDESC_JABBER_TIMEOUT	0x00000002
#define TXDESC_LOCAL_FAULT	0x00000004
#define TXDESC_REMOTE_FAULT	0x00000008
#define TXDESC_VLAN_FRAME	0x00000010
#define TXDESC_FRAME_FLUSHED	0x00000020
#define TXDESC_IP_HEADER_ERR	0x00000040
#define TXDESC_PAYLOAD_CSUM_ERR	0x00000080
#define TXDESC_ERROR_SUMMARY	0x00008000
#define TXDESC_SA_CTRL_INSERT	0x00040000
#define TXDESC_SA_CTRL_REPLACE	0x00080000
#define TXDESC_2ND_ADDR_CHAINED	0x00100000
#define TXDESC_END_RING		0x00200000
#define TXDESC_CSUM_IP		0x00400000
#define TXDESC_CSUM_IP_PAYLD	0x00800000
#define TXDESC_CSUM_ALL		0x00C00000
#define TXDESC_CRC_EN_REPLACE	0x01000000
#define TXDESC_CRC_EN_APPEND	0x02000000
#define TXDESC_DISABLE_PAD	0x04000000
#define TXDESC_FIRST_SEG	0x10000000
#define TXDESC_LAST_SEG		0x20000000
#define TXDESC_INTERRUPT	0x40000000

#define DESC_OWN		0x80000000
#define DESC_BUFFER1_SZ_MASK	0x00001fff
#define DESC_BUFFER2_SZ_MASK	0x1fff0000
#define DESC_BUFFER2_SZ_OFFSET	16

struct xgmac_dma_desc {
	__le32 flags;
	__le32 buf_size;
	__le32 buf1_addr;		/* Buffer 1 Address Pointer */
	__le32 buf2_addr;		/* Buffer 2 Address Pointer */
	__le32 ext_status;
	__le32 res[3];
};

struct xgmac_extra_stats {
	/* Transmit errors */
	unsigned long tx_jabber;
	unsigned long tx_frame_flushed;
	unsigned long tx_payload_error;
	unsigned long tx_ip_header_error;
	unsigned long tx_local_fault;
	unsigned long tx_remote_fault;
	/* Receive errors */
	unsigned long rx_watchdog;
	unsigned long rx_da_filter_fail;
	unsigned long rx_sa_filter_fail;
	unsigned long rx_payload_error;
	unsigned long rx_ip_header_error;
	/* Tx/Rx IRQ errors */
	unsigned long tx_undeflow;
	unsigned long tx_process_stopped;
	unsigned long rx_buf_unav;
	unsigned long rx_process_stopped;
	unsigned long tx_early;
	unsigned long fatal_bus_error;
};

struct xgmac_priv {
	struct xgmac_dma_desc *dma_rx;
	struct sk_buff **rx_skbuff;
	unsigned int rx_tail;
	unsigned int rx_head;

	struct xgmac_dma_desc *dma_tx;
	struct sk_buff **tx_skbuff;
	unsigned int tx_head;
	unsigned int tx_tail;

	void __iomem *base;
	unsigned int dma_buf_sz;
	dma_addr_t dma_rx_phy;
	dma_addr_t dma_tx_phy;

	struct net_device *dev;
	struct device *device;
	struct napi_struct napi;

	struct xgmac_extra_stats xstats;

	spinlock_t stats_lock;
	int pmt_irq;
	char rx_pause;
	char tx_pause;
	int wolopts;
};

/* XGMAC Configuration Settings */
#define MAX_MTU			9000
#define PAUSE_TIME		0x400

#define DMA_RX_RING_SZ		256
#define DMA_TX_RING_SZ		128
/* minimum number of free TX descriptors required to wake up TX process */
#define TX_THRESH		(DMA_TX_RING_SZ/4)

/* DMA descriptor ring helpers */
#define dma_ring_incr(n, s)	(((n) + 1) & ((s) - 1))
#define dma_ring_space(h, t, s)	CIRC_SPACE(h, t, s)
#define dma_ring_cnt(h, t, s)	CIRC_CNT(h, t, s)

/* XGMAC Descriptor Access Helpers */
static inline void desc_set_buf_len(struct xgmac_dma_desc *p, u32 buf_sz)
{
	if (buf_sz > MAX_DESC_BUF_SZ)
		p->buf_size = cpu_to_le32(MAX_DESC_BUF_SZ |
			(buf_sz - MAX_DESC_BUF_SZ) << DESC_BUFFER2_SZ_OFFSET);
	else
		p->buf_size = cpu_to_le32(buf_sz);
}

static inline int desc_get_buf_len(struct xgmac_dma_desc *p)
{
	u32 len = cpu_to_le32(p->flags);
	return (len & DESC_BUFFER1_SZ_MASK) +
		((len & DESC_BUFFER2_SZ_MASK) >> DESC_BUFFER2_SZ_OFFSET);
}

static inline void desc_init_rx_desc(struct xgmac_dma_desc *p, int ring_size,
				     int buf_sz)
{
	struct xgmac_dma_desc *end = p + ring_size - 1;

	memset(p, 0, sizeof(*p) * ring_size);

	for (; p <= end; p++)
		desc_set_buf_len(p, buf_sz);

	end->buf_size |= cpu_to_le32(RXDESC1_END_RING);
}

static inline void desc_init_tx_desc(struct xgmac_dma_desc *p, u32 ring_size)
{
	memset(p, 0, sizeof(*p) * ring_size);
	p[ring_size - 1].flags = cpu_to_le32(TXDESC_END_RING);
}

static inline int desc_get_owner(struct xgmac_dma_desc *p)
{
	return le32_to_cpu(p->flags) & DESC_OWN;
}

static inline void desc_set_rx_owner(struct xgmac_dma_desc *p)
{
	/* Clear all fields and set the owner */
	p->flags = cpu_to_le32(DESC_OWN);
}

static inline void desc_set_tx_owner(struct xgmac_dma_desc *p, u32 flags)
{
	u32 tmpflags = le32_to_cpu(p->flags);
	tmpflags &= TXDESC_END_RING;
	tmpflags |= flags | DESC_OWN;
	p->flags = cpu_to_le32(tmpflags);
}

static inline int desc_get_tx_ls(struct xgmac_dma_desc *p)
{
	return le32_to_cpu(p->flags) & TXDESC_LAST_SEG;
}

static inline u32 desc_get_buf_addr(struct xgmac_dma_desc *p)
{
	return le32_to_cpu(p->buf1_addr);
}

static inline void desc_set_buf_addr(struct xgmac_dma_desc *p,
				     u32 paddr, int len)
{
	p->buf1_addr = cpu_to_le32(paddr);
	if (len > MAX_DESC_BUF_SZ)
		p->buf2_addr = cpu_to_le32(paddr + MAX_DESC_BUF_SZ);
}

static inline void desc_set_buf_addr_and_size(struct xgmac_dma_desc *p,
					      u32 paddr, int len)
{
	desc_set_buf_len(p, len);
	desc_set_buf_addr(p, paddr, len);
}

static inline int desc_get_rx_frame_len(struct xgmac_dma_desc *p)
{
	u32 data = le32_to_cpu(p->flags);
	u32 len = (data & RXDESC_FRAME_LEN_MASK) >> RXDESC_FRAME_LEN_OFFSET;
	if (data & RXDESC_FRAME_TYPE)
		len -= ETH_FCS_LEN;

	return len;
}

static void xgmac_dma_flush_tx_fifo(void __iomem *ioaddr)
{
	int timeout = 1000;
	u32 reg = readl(ioaddr + XGMAC_OMR);
	writel(reg | XGMAC_OMR_FTF, ioaddr + XGMAC_OMR);

	while ((timeout-- > 0) && readl(ioaddr + XGMAC_OMR) & XGMAC_OMR_FTF)
		udelay(1);
}

static int desc_get_tx_status(struct xgmac_priv *priv, struct xgmac_dma_desc *p)
{
	struct xgmac_extra_stats *x = &priv->xstats;
	u32 status = le32_to_cpu(p->flags);

	if (!(status & TXDESC_ERROR_SUMMARY))
		return 0;

	netdev_dbg(priv->dev, "tx desc error = 0x%08x\n", status);
	if (status & TXDESC_JABBER_TIMEOUT)
		x->tx_jabber++;
	if (status & TXDESC_FRAME_FLUSHED)
		x->tx_frame_flushed++;
	if (status & TXDESC_UNDERFLOW_ERR)
		xgmac_dma_flush_tx_fifo(priv->base);
	if (status & TXDESC_IP_HEADER_ERR)
		x->tx_ip_header_error++;
	if (status & TXDESC_LOCAL_FAULT)
		x->tx_local_fault++;
	if (status & TXDESC_REMOTE_FAULT)
		x->tx_remote_fault++;
	if (status & TXDESC_PAYLOAD_CSUM_ERR)
		x->tx_payload_error++;

	return -1;
}

static int desc_get_rx_status(struct xgmac_priv *priv, struct xgmac_dma_desc *p)
{
	struct xgmac_extra_stats *x = &priv->xstats;
	int ret = CHECKSUM_UNNECESSARY;
	u32 status = le32_to_cpu(p->flags);
	u32 ext_status = le32_to_cpu(p->ext_status);

	if (status & RXDESC_DA_FILTER_FAIL) {
		netdev_dbg(priv->dev, "XGMAC RX : Dest Address filter fail\n");
		x->rx_da_filter_fail++;
		return -1;
	}

	/* Check if packet has checksum already */
	if ((status & RXDESC_FRAME_TYPE) && (status & RXDESC_EXT_STATUS) &&
		!(ext_status & RXDESC_IP_PAYLOAD_MASK))
		ret = CHECKSUM_NONE;

	netdev_dbg(priv->dev, "rx status - frame type=%d, csum = %d, ext stat %08x\n",
		   (status & RXDESC_FRAME_TYPE) ? 1 : 0, ret, ext_status);

	if (!(status & RXDESC_ERROR_SUMMARY))
		return ret;

	/* Handle any errors */
	if (status & (RXDESC_DESCRIPTOR_ERR | RXDESC_OVERFLOW_ERR |
		RXDESC_GIANT_FRAME | RXDESC_LENGTH_ERR | RXDESC_CRC_ERR))
		return -1;

	if (status & RXDESC_EXT_STATUS) {
		if (ext_status & RXDESC_IP_HEADER_ERR)
			x->rx_ip_header_error++;
		if (ext_status & RXDESC_IP_PAYLOAD_ERR)
			x->rx_payload_error++;
		netdev_dbg(priv->dev, "IP checksum error - stat %08x\n",
			   ext_status);
		return CHECKSUM_NONE;
	}

	return ret;
}

static inline void xgmac_mac_enable(void __iomem *ioaddr)
{
	u32 value = readl(ioaddr + XGMAC_CONTROL);
	value |= MAC_ENABLE_RX | MAC_ENABLE_TX;
	writel(value, ioaddr + XGMAC_CONTROL);

	value = readl(ioaddr + XGMAC_DMA_CONTROL);
	value |= DMA_CONTROL_ST | DMA_CONTROL_SR;
	writel(value, ioaddr + XGMAC_DMA_CONTROL);
}

static inline void xgmac_mac_disable(void __iomem *ioaddr)
{
	u32 value = readl(ioaddr + XGMAC_DMA_CONTROL);
	value &= ~(DMA_CONTROL_ST | DMA_CONTROL_SR);
	writel(value, ioaddr + XGMAC_DMA_CONTROL);

	value = readl(ioaddr + XGMAC_CONTROL);
	value &= ~(MAC_ENABLE_TX | MAC_ENABLE_RX);
	writel(value, ioaddr + XGMAC_CONTROL);
}

static void xgmac_set_mac_addr(void __iomem *ioaddr, unsigned char *addr,
			       int num)
{
	u32 data;

	data = (addr[5] << 8) | addr[4] | (num ? XGMAC_ADDR_AE : 0);
	writel(data, ioaddr + XGMAC_ADDR_HIGH(num));
	data = (addr[3] << 24) | (addr[2] << 16) | (addr[1] << 8) | addr[0];
	writel(data, ioaddr + XGMAC_ADDR_LOW(num));
}

static void xgmac_get_mac_addr(void __iomem *ioaddr, unsigned char *addr,
			       int num)
{
	u32 hi_addr, lo_addr;

	/* Read the MAC address from the hardware */
	hi_addr = readl(ioaddr + XGMAC_ADDR_HIGH(num));
	lo_addr = readl(ioaddr + XGMAC_ADDR_LOW(num));

	/* Extract the MAC address from the high and low words */
	addr[0] = lo_addr & 0xff;
	addr[1] = (lo_addr >> 8) & 0xff;
	addr[2] = (lo_addr >> 16) & 0xff;
	addr[3] = (lo_addr >> 24) & 0xff;
	addr[4] = hi_addr & 0xff;
	addr[5] = (hi_addr >> 8) & 0xff;
}

static int xgmac_set_flow_ctrl(struct xgmac_priv *priv, int rx, int tx)
{
	u32 reg;
	unsigned int flow = 0;

	priv->rx_pause = rx;
	priv->tx_pause = tx;

	if (rx || tx) {
		if (rx)
			flow |= XGMAC_FLOW_CTRL_RFE;
		if (tx)
			flow |= XGMAC_FLOW_CTRL_TFE;

		flow |= XGMAC_FLOW_CTRL_PLT | XGMAC_FLOW_CTRL_UP;
		flow |= (PAUSE_TIME << XGMAC_FLOW_CTRL_PT_SHIFT);

		writel(flow, priv->base + XGMAC_FLOW_CTRL);

		reg = readl(priv->base + XGMAC_OMR);
		reg |= XGMAC_OMR_EFC;
		writel(reg, priv->base + XGMAC_OMR);
	} else {
		writel(0, priv->base + XGMAC_FLOW_CTRL);

		reg = readl(priv->base + XGMAC_OMR);
		reg &= ~XGMAC_OMR_EFC;
		writel(reg, priv->base + XGMAC_OMR);
	}

	return 0;
}

static void xgmac_rx_refill(struct xgmac_priv *priv)
{
	struct xgmac_dma_desc *p;
	dma_addr_t paddr;

	while (dma_ring_space(priv->rx_head, priv->rx_tail, DMA_RX_RING_SZ) > 1) {
		int entry = priv->rx_head;
		struct sk_buff *skb;

		p = priv->dma_rx + entry;

		if (priv->rx_skbuff[entry] == NULL) {
			skb = netdev_alloc_skb(priv->dev, priv->dma_buf_sz);
			if (unlikely(skb == NULL))
				break;

			priv->rx_skbuff[entry] = skb;
			paddr = dma_map_single(priv->device, skb->data,
					       priv->dma_buf_sz, DMA_FROM_DEVICE);
			desc_set_buf_addr(p, paddr, priv->dma_buf_sz);
		}

		netdev_dbg(priv->dev, "rx ring: head %d, tail %d\n",
			priv->rx_head, priv->rx_tail);

		priv->rx_head = dma_ring_incr(priv->rx_head, DMA_RX_RING_SZ);
		desc_set_rx_owner(p);
	}
}

/**
 * init_xgmac_dma_desc_rings - init the RX/TX descriptor rings
 * @dev: net device structure
 * Description:  this function initializes the DMA RX/TX descriptors
 * and allocates the socket buffers.
 */
static int xgmac_dma_desc_rings_init(struct net_device *dev)
{
	struct xgmac_priv *priv = netdev_priv(dev);
	unsigned int bfsize;

	/* Set the Buffer size according to the MTU;
	 * indeed, in case of jumbo we need to bump-up the buffer sizes.
	 */
	bfsize = ALIGN(dev->mtu + ETH_HLEN + ETH_FCS_LEN + NET_IP_ALIGN + 64,
		       64);

	netdev_dbg(priv->dev, "mtu [%d] bfsize [%d]\n", dev->mtu, bfsize);

	priv->rx_skbuff = kzalloc(sizeof(struct sk_buff *) * DMA_RX_RING_SZ,
				  GFP_KERNEL);
	if (!priv->rx_skbuff)
		return -ENOMEM;

	priv->dma_rx = dma_alloc_coherent(priv->device,
					  DMA_RX_RING_SZ *
					  sizeof(struct xgmac_dma_desc),
					  &priv->dma_rx_phy,
					  GFP_KERNEL);
	if (!priv->dma_rx)
		goto err_dma_rx;

	priv->tx_skbuff = kzalloc(sizeof(struct sk_buff *) * DMA_TX_RING_SZ,
				  GFP_KERNEL);
	if (!priv->tx_skbuff)
		goto err_tx_skb;

	priv->dma_tx = dma_alloc_coherent(priv->device,
					  DMA_TX_RING_SZ *
					  sizeof(struct xgmac_dma_desc),
					  &priv->dma_tx_phy,
					  GFP_KERNEL);
	if (!priv->dma_tx)
		goto err_dma_tx;

	netdev_dbg(priv->dev, "DMA desc rings: virt addr (Rx %p, "
	    "Tx %p)\n\tDMA phy addr (Rx 0x%08x, Tx 0x%08x)\n",
	    priv->dma_rx, priv->dma_tx,
	    (unsigned int)priv->dma_rx_phy, (unsigned int)priv->dma_tx_phy);

	priv->rx_tail = 0;
	priv->rx_head = 0;
	priv->dma_buf_sz = bfsize;
	desc_init_rx_desc(priv->dma_rx, DMA_RX_RING_SZ, priv->dma_buf_sz);
	xgmac_rx_refill(priv);

	priv->tx_tail = 0;
	priv->tx_head = 0;
	desc_init_tx_desc(priv->dma_tx, DMA_TX_RING_SZ);

	writel(priv->dma_tx_phy, priv->base + XGMAC_DMA_TX_BASE_ADDR);
	writel(priv->dma_rx_phy, priv->base + XGMAC_DMA_RX_BASE_ADDR);

	return 0;

err_dma_tx:
	kfree(priv->tx_skbuff);
err_tx_skb:
	dma_free_coherent(priv->device,
			  DMA_RX_RING_SZ * sizeof(struct xgmac_dma_desc),
			  priv->dma_rx, priv->dma_rx_phy);
err_dma_rx:
	kfree(priv->rx_skbuff);
	return -ENOMEM;
}

static void xgmac_free_rx_skbufs(struct xgmac_priv *priv)
{
	int i;
	struct xgmac_dma_desc *p;

	if (!priv->rx_skbuff)
		return;

	for (i = 0; i < DMA_RX_RING_SZ; i++) {
		if (priv->rx_skbuff[i] == NULL)
			continue;

		p = priv->dma_rx + i;
		dma_unmap_single(priv->device, desc_get_buf_addr(p),
				 priv->dma_buf_sz, DMA_FROM_DEVICE);
		dev_kfree_skb_any(priv->rx_skbuff[i]);
		priv->rx_skbuff[i] = NULL;
	}
}

static void xgmac_free_tx_skbufs(struct xgmac_priv *priv)
{
	int i, f;
	struct xgmac_dma_desc *p;

	if (!priv->tx_skbuff)
		return;

	for (i = 0; i < DMA_TX_RING_SZ; i++) {
		if (priv->tx_skbuff[i] == NULL)
			continue;

		p = priv->dma_tx + i;
		dma_unmap_single(priv->device, desc_get_buf_addr(p),
				 desc_get_buf_len(p), DMA_TO_DEVICE);

		for (f = 0; f < skb_shinfo(priv->tx_skbuff[i])->nr_frags; f++) {
			p = priv->dma_tx + i++;
			dma_unmap_page(priv->device, desc_get_buf_addr(p),
				       desc_get_buf_len(p), DMA_TO_DEVICE);
		}

		dev_kfree_skb_any(priv->tx_skbuff[i]);
		priv->tx_skbuff[i] = NULL;
	}
}

static void xgmac_free_dma_desc_rings(struct xgmac_priv *priv)
{
	/* Release the DMA TX/RX socket buffers */
	xgmac_free_rx_skbufs(priv);
	xgmac_free_tx_skbufs(priv);

	/* Free the consistent memory allocated for descriptor rings */
	if (priv->dma_tx) {
		dma_free_coherent(priv->device,
				  DMA_TX_RING_SZ * sizeof(struct xgmac_dma_desc),
				  priv->dma_tx, priv->dma_tx_phy);
		priv->dma_tx = NULL;
	}
	if (priv->dma_rx) {
		dma_free_coherent(priv->device,
				  DMA_RX_RING_SZ * sizeof(struct xgmac_dma_desc),
				  priv->dma_rx, priv->dma_rx_phy);
		priv->dma_rx = NULL;
	}
	kfree(priv->rx_skbuff);
	priv->rx_skbuff = NULL;
	kfree(priv->tx_skbuff);
	priv->tx_skbuff = NULL;
}

/**
 * xgmac_tx:
 * @priv: private driver structure
 * Description: it reclaims resources after transmission completes.
 */
static void xgmac_tx_complete(struct xgmac_priv *priv)
{
	int i;
	void __iomem *ioaddr = priv->base;

	writel(DMA_STATUS_TU | DMA_STATUS_NIS, ioaddr + XGMAC_DMA_STATUS);

	while (dma_ring_cnt(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ)) {
		unsigned int entry = priv->tx_tail;
		struct sk_buff *skb = priv->tx_skbuff[entry];
		struct xgmac_dma_desc *p = priv->dma_tx + entry;

		/* Check if the descriptor is owned by the DMA. */
		if (desc_get_owner(p))
			break;

		/* Verify tx error by looking at the last segment */
		if (desc_get_tx_ls(p))
			desc_get_tx_status(priv, p);

		netdev_dbg(priv->dev, "tx ring: curr %d, dirty %d\n",
			priv->tx_head, priv->tx_tail);

		dma_unmap_single(priv->device, desc_get_buf_addr(p),
				 desc_get_buf_len(p), DMA_TO_DEVICE);

		priv->tx_skbuff[entry] = NULL;
		priv->tx_tail = dma_ring_incr(entry, DMA_TX_RING_SZ);

		if (!skb) {
			continue;
		}

		for (i = 0; i < skb_shinfo(skb)->nr_frags; i++) {
			entry = priv->tx_tail = dma_ring_incr(priv->tx_tail,
							      DMA_TX_RING_SZ);
			p = priv->dma_tx + priv->tx_tail;

			dma_unmap_page(priv->device, desc_get_buf_addr(p),
				       desc_get_buf_len(p), DMA_TO_DEVICE);
		}

		dev_kfree_skb(skb);
	}

	if (dma_ring_space(priv->tx_head, priv->tx_tail, DMA_TX_RING_SZ) >
	    TX_THRESH)
		netif_wake_queue(priv->dev);
}

/**
 * xgmac_tx_err:
 * @priv: pointer to the private device structure
 * Description: it cleans the descriptors and restarts the transmission
 * in case of errors.
 */
static void xgmac_tx_err(struct xgmac_priv *priv)
{
	u32 reg, value, inten;

	netif_stop_queue(priv->dev);

	inten = readl(priv->base + XGMAC_DMA_INTR_ENA);
	writel(0, priv->base + XGMAC_DMA_INTR_ENA);

	reg = readl(priv->base + XGMAC_DMA_CONTROL);
	writel(reg & ~DMA_CONTROL_ST, priv->base + XGMAC_DMA_CONTROL);
	do {
		value = readl(priv->base + XGMAC_DMA_STATUS) & 0x700000;
	} while (value && (value != 0x600000));

	xgmac_free_tx_skbufs(priv);
	desc_init_tx_desc(priv->dma_tx, DMA_TX_RING_SZ);
	priv->tx_tail = 0;
	priv->tx_head = 0;
	writel(priv->dma_tx_phy, priv->base + XGMAC_DMA_TX_BASE_ADDR);
	writel(reg | DMA_CONTROL_ST, priv->base + XGMAC_DMA_CONTROL);

	writel(DMA_STATUS_TU | DMA_STATUS_TPS | DMA_STATUS_NIS | DMA_STATUS_AIS,
		priv->base + XGMAC_DMA_STATUS);
	writel(inten, priv->base + XGMAC_DMA_INTR_ENA);

	netif_wake_queue(priv->dev);
}

static int xgmac_hw_init(struct net_device *dev)
{
	u32 value, ctrl;
	int limit;
	struct xgmac_priv *priv = netdev_priv(dev);
	void __iomem *ioaddr = priv->base;

	/* Save the ctrl register value */
	ctrl = readl(ioaddr + XGMAC_CONTROL) & XGMAC_CONTROL_SPD_MASK;

	/* SW reset */
	value = DMA_BUS_MODE_SFT_RESET;
	writel(value, ioaddr + XGMAC_DMA_BUS_MODE);
	limit = 15000;
	while (limit-- &&
		(readl(ioaddr + XGMAC_DMA_BUS_MODE) & DMA_BUS_MODE_SFT_RESET))
		cpu_relax();
	if (limit < 0)
		return -EBUSY;

	value = (0x10 << DMA_BUS_MODE_PBL_SHIFT) |
		(0x10 << DMA_BUS_MODE_RPBL_SHIFT) |
		DMA_BUS_MODE_FB | DMA_BUS_MODE_ATDS | DMA_BUS_MODE_AAL;
	writel(value, ioaddr + XGMAC_DMA_BUS_MODE);

	/* Enable interrupts */
	writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_STATUS);
	writel(DMA_INTR_DEFAULT_MASK, ioaddr + XGMAC_DMA_INTR_ENA);

	/* XGMAC requires AXI bus init. This is a 'magic number' for now */
	writel(0x0077000E, ioaddr + XGMAC_DMA_AXI_BUS);

	ctrl |= XGMAC_CONTROL_DDIC | XGMAC_CONTROL_JE | XGMAC_CONTROL_ACS |
		XGMAC_CONTROL_CAR;
	if (dev->features & NETIF_F_RXCSUM)
		ctrl |= XGMAC_CONTROL_IPC;
	writel(ctrl, ioaddr + XGMAC_CONTROL);

	writel(DMA_CONTROL_DFF | DMA_CONTROL_OSF, ioaddr + XGMAC_DMA_CONTROL);

	/* Set the HW DMA mode and the COE */
	writel(XGMAC_OMR_TSF | XGMAC_OMR_RFD | XGMAC_OMR_RFA |
		XGMAC_OMR_RTC_256,
		ioaddr + XGMAC_OMR);

	/* Reset the MMC counters */
	writel(1, ioaddr + XGMAC_MMC_CTRL);
	return 0;
}

/**
 *  xgmac_open - open entry point of the driver
 *  @dev : pointer to the device structure.
 *  Description:
 *  This function is the open entry point of the driver.
 *  Return value:
 *  0 on success and an appropriate (-)ve integer as defined in errno.h
 *  file on failure.
 */
static int xgmac_open(struct net_device *dev)
{
	int ret;
	struct xgmac_priv *priv = netdev_priv(dev);
	void __iomem *ioaddr = priv->base;

	/* Check that the MAC address is valid.  If its not, refuse
	 * to bring the device up. The user must specify an
	 * address using the following linux command:
	 *      ifconfig eth0 hw ether xx:xx:xx:xx:xx:xx  */
	if (!is_valid_ether_addr(dev->dev_addr)) {