/*
 * sata_mv.c - Marvell SATA support
 *
 * Copyright 2008-2009: Marvell Corporation, all rights reserved.
 * Copyright 2005: EMC Corporation, all rights reserved.
 * Copyright 2005 Red Hat, Inc.  All rights reserved.
 *
 * Originally written by Brett Russ.
 * Extensive overhaul and enhancement by Mark Lord <mlord@pobox.com>.
 *
 * Please ALWAYS copy linux-ide@vger.kernel.org on emails.
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; version 2 of the License.
 *
 * This program is distributed in the hope that 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 *
 */

/*
 * sata_mv TODO list:
 *
 * --> Develop a low-power-consumption strategy, and implement it.
 *
 * --> Add sysfs attributes for per-chip / per-HC IRQ coalescing thresholds.
 *
 * --> [Experiment, Marvell value added] Is it possible to use target
 *       mode to cross-connect two Linux boxes with Marvell cards?  If so,
 *       creating LibATA target mode support would be very interesting.
 *
 *       Target mode, for those without docs, is the ability to directly
 *       connect two SATA ports.
 */

/*
 * 80x1-B2 errata PCI#11:
 *
 * Users of the 6041/6081 Rev.B2 chips (current is C0)
 * should be careful to insert those cards only onto PCI-X bus #0,
 * and only in device slots 0..7, not higher.  The chips may not
 * work correctly otherwise  (note: this is a pretty rare condition).
 */

#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/pci.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/delay.h>
#include <linux/interrupt.h>
#include <linux/dmapool.h>
#include <linux/dma-mapping.h>
#include <linux/device.h>
#include <linux/platform_device.h>
#include <linux/ata_platform.h>
#include <linux/mbus.h>
#include <linux/bitops.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_device.h>
#include <linux/libata.h>

#define DRV_NAME        "sata_mv"
#define DRV_VERSION     "1.28"

/*
 * module options
 */

static int msi;
#ifdef CONFIG_PCI
module_param(msi, int, S_IRUGO);
MODULE_PARM_DESC(msi, "Enable use of PCI MSI (0=off, 1=on)");
#endif

static int irq_coalescing_io_count;
module_param(irq_coalescing_io_count, int, S_IRUGO);
MODULE_PARM_DESC(irq_coalescing_io_count,
                 "IRQ coalescing I/O count threshold (0..255)");

static int irq_coalescing_usecs;
module_param(irq_coalescing_usecs, int, S_IRUGO);
MODULE_PARM_DESC(irq_coalescing_usecs,
                 "IRQ coalescing time threshold in usecs");

enum {
        /* BAR's are enumerated in terms of pci_resource_start() terms */
        MV_PRIMARY_BAR          = 0,    /* offset 0x10: memory space */
        MV_IO_BAR               = 2,    /* offset 0x18: IO space */
        MV_MISC_BAR             = 3,    /* offset 0x1c: FLASH, NVRAM, SRAM */

        MV_MAJOR_REG_AREA_SZ    = 0x10000,      /* 64KB */
        MV_MINOR_REG_AREA_SZ    = 0x2000,       /* 8KB */

        /* For use with both IRQ coalescing methods ("all ports" or "per-HC" */
        COAL_CLOCKS_PER_USEC    = 150,          /* for calculating COAL_TIMEs */
        MAX_COAL_TIME_THRESHOLD = ((1 << 24) - 1), /* internal clocks count */
        MAX_COAL_IO_COUNT       = 255,          /* completed I/O count */

        MV_PCI_REG_BASE         = 0,

        /*
         * Per-chip ("all ports") interrupt coalescing feature.
         * This is only for GEN_II / GEN_IIE hardware.
         *
         * Coalescing defers the interrupt until either the IO_THRESHOLD
         * (count of completed I/Os) is met, or the TIME_THRESHOLD is met.
         */
        COAL_REG_BASE           = 0x18000,
        IRQ_COAL_CAUSE          = (COAL_REG_BASE + 0x08),
        ALL_PORTS_COAL_IRQ      = (1 << 4),     /* all ports irq event */

        IRQ_COAL_IO_THRESHOLD   = (COAL_REG_BASE + 0xcc),
        IRQ_COAL_TIME_THRESHOLD = (COAL_REG_BASE + 0xd0),

        /*
         * Registers for the (unused here) transaction coalescing feature:
         */
        TRAN_COAL_CAUSE_LO      = (COAL_REG_BASE + 0x88),
        TRAN_COAL_CAUSE_HI      = (COAL_REG_BASE + 0x8c),

        SATAHC0_REG_BASE        = 0x20000,
        FLASH_CTL               = 0x1046c,
        GPIO_PORT_CTL           = 0x104f0,
        RESET_CFG               = 0x180d8,

        MV_PCI_REG_SZ           = MV_MAJOR_REG_AREA_SZ,
        MV_SATAHC_REG_SZ        = MV_MAJOR_REG_AREA_SZ,
        MV_SATAHC_ARBTR_REG_SZ  = MV_MINOR_REG_AREA_SZ,         /* arbiter */
        MV_PORT_REG_SZ          = MV_MINOR_REG_AREA_SZ,

        MV_MAX_Q_DEPTH          = 32,
        MV_MAX_Q_DEPTH_MASK     = MV_MAX_Q_DEPTH - 1,

        /* CRQB needs alignment on a 1KB boundary. Size == 1KB
         * CRPB needs alignment on a 256B boundary. Size == 256B
         * ePRD (SG) entries need alignment on a 16B boundary. Size == 16B
         */
        MV_CRQB_Q_SZ            = (32 * MV_MAX_Q_DEPTH),
        MV_CRPB_Q_SZ            = (8 * MV_MAX_Q_DEPTH),
        MV_MAX_SG_CT            = 256,
        MV_SG_TBL_SZ            = (16 * MV_MAX_SG_CT),

        /* Determine hc from 0-7 port: hc = port >> MV_PORT_HC_SHIFT */
        MV_PORT_HC_SHIFT        = 2,
        MV_PORTS_PER_HC         = (1 << MV_PORT_HC_SHIFT), /* 4 */
        /* Determine hc port from 0-7 port: hardport = port & MV_PORT_MASK */
        MV_PORT_MASK            = (MV_PORTS_PER_HC - 1),   /* 3 */

        /* Host Flags */
        MV_FLAG_DUAL_HC         = (1 << 30),  /* two SATA Host Controllers */

        MV_COMMON_FLAGS         = ATA_FLAG_SATA | ATA_FLAG_NO_LEGACY |
                                  ATA_FLAG_MMIO | ATA_FLAG_PIO_POLLING,

        MV_GEN_I_FLAGS          = MV_COMMON_FLAGS | ATA_FLAG_NO_ATAPI,

        MV_GEN_II_FLAGS         = MV_COMMON_FLAGS | ATA_FLAG_NCQ |
                                  ATA_FLAG_PMP | ATA_FLAG_ACPI_SATA,

        MV_GEN_IIE_FLAGS        = MV_GEN_II_FLAGS | ATA_FLAG_AN,

        CRQB_FLAG_READ          = (1 << 0),
        CRQB_TAG_SHIFT          = 1,
        CRQB_IOID_SHIFT         = 6,    /* CRQB Gen-II/IIE IO Id shift */
        CRQB_PMP_SHIFT          = 12,   /* CRQB Gen-II/IIE PMP shift */
        CRQB_HOSTQ_SHIFT        = 17,   /* CRQB Gen-II/IIE HostQueTag shift */
        CRQB_CMD_ADDR_SHIFT     = 8,
        CRQB_CMD_CS             = (0x2 << 11),
        CRQB_CMD_LAST           = (1 << 15),

        CRPB_FLAG_STATUS_SHIFT  = 8,
        CRPB_IOID_SHIFT_6       = 5,    /* CRPB Gen-II IO Id shift */
        CRPB_IOID_SHIFT_7       = 7,    /* CRPB Gen-IIE IO Id shift */

        EPRD_FLAG_END_OF_TBL    = (1 << 31),

        /* PCI interface registers */

        MV_PCI_COMMAND          = 0xc00,
        MV_PCI_COMMAND_MWRCOM   = (1 << 4),     /* PCI Master Write Combining */
        MV_PCI_COMMAND_MRDTRIG  = (1 << 7),     /* PCI Master Read Trigger */

        PCI_MAIN_CMD_STS        = 0xd30,
        STOP_PCI_MASTER         = (1 << 2),
        PCI_MASTER_EMPTY        = (1 << 3),
        GLOB_SFT_RST            = (1 << 4),

        MV_PCI_MODE             = 0xd00,
        MV_PCI_MODE_MASK        = 0x30,

        MV_PCI_EXP_ROM_BAR_CTL  = 0xd2c,
        MV_PCI_DISC_TIMER       = 0xd04,
        MV_PCI_MSI_TRIGGER      = 0xc38,
        MV_PCI_SERR_MASK        = 0xc28,
        MV_PCI_XBAR_TMOUT       = 0x1d04,
        MV_PCI_ERR_LOW_ADDRESS  = 0x1d40,
        MV_PCI_ERR_HIGH_ADDRESS = 0x1d44,
        MV_PCI_ERR_ATTRIBUTE    = 0x1d48,
        MV_PCI_ERR_COMMAND      = 0x1d50,

        PCI_IRQ_CAUSE           = 0x1d58,
        PCI_IRQ_MASK            = 0x1d5c,
        PCI_UNMASK_ALL_IRQS     = 0x7fffff,     /* bits 22-0 */

        PCIE_IRQ_CAUSE          = 0x1900,
        PCIE_IRQ_MASK           = 0x1910,
        PCIE_UNMASK_ALL_IRQS    = 0x40a,        /* assorted bits */

        /* Host Controller Main Interrupt Cause/Mask registers (1 per-chip) */
        PCI_HC_MAIN_IRQ_CAUSE   = 0x1d60,
        PCI_HC_MAIN_IRQ_MASK    = 0x1d64,
        SOC_HC_MAIN_IRQ_CAUSE   = 0x20020,
        SOC_HC_MAIN_IRQ_MASK    = 0x20024,
        ERR_IRQ                 = (1 << 0),     /* shift by (2 * port #) */
        DONE_IRQ                = (1 << 1),     /* shift by (2 * port #) */
        HC0_IRQ_PEND            = 0x1ff,        /* bits 0-8 = HC0's ports */
        HC_SHIFT                = 9,            /* bits 9-17 = HC1's ports */
        DONE_IRQ_0_3            = 0x000000aa,   /* DONE_IRQ ports 0,1,2,3 */
        DONE_IRQ_4_7            = (DONE_IRQ_0_3 << HC_SHIFT),  /* 4,5,6,7 */
        PCI_ERR                 = (1 << 18),
        TRAN_COAL_LO_DONE       = (1 << 19),    /* transaction coalescing */
        TRAN_COAL_HI_DONE       = (1 << 20),    /* transaction coalescing */
        PORTS_0_3_COAL_DONE     = (1 << 8),     /* HC0 IRQ coalescing */
        PORTS_4_7_COAL_DONE     = (1 << 17),    /* HC1 IRQ coalescing */
        ALL_PORTS_COAL_DONE     = (1 << 21),    /* GEN_II(E) IRQ coalescing */
        GPIO_INT                = (1 << 22),
        SELF_INT                = (1 << 23),
        TWSI_INT                = (1 << 24),
        HC_MAIN_RSVD            = (0x7f << 25), /* bits 31-25 */
        HC_MAIN_RSVD_5          = (0x1fff << 19), /* bits 31-19 */
        HC_MAIN_RSVD_SOC        = (0x3fffffb << 6),     /* bits 31-9, 7-6 */

        /* SATAHC registers */
        HC_CFG                  = 0x00,

        HC_IRQ_CAUSE            = 0x14,
        DMA_IRQ                 = (1 << 0),     /* shift by port # */
        HC_COAL_IRQ             = (1 << 4),     /* IRQ coalescing */
        DEV_IRQ                 = (1 << 8),     /* shift by port # */

        /*
         * Per-HC (Host-Controller) interrupt coalescing feature.
         * This is present on all chip generations.
         *
         * Coalescing defers the interrupt until either the IO_THRESHOLD
         * (count of completed I/Os) is met, or the TIME_THRESHOLD is met.
         */
        HC_IRQ_COAL_IO_THRESHOLD        = 0x000c,
        HC_IRQ_COAL_TIME_THRESHOLD      = 0x0010,

        SOC_LED_CTRL            = 0x2c,
        SOC_LED_CTRL_BLINK      = (1 << 0),     /* Active LED blink */
        SOC_LED_CTRL_ACT_PRESENCE = (1 << 2),   /* Multiplex dev presence */
                                                /*  with dev activity LED */

        /* Shadow block registers */
        SHD_BLK                 = 0x100,
        SHD_CTL_AST             = 0x20,         /* ofs from SHD_BLK */

        /* SATA registers */
        SATA_STATUS             = 0x300,  /* ctrl, err regs follow status */
        SATA_ACTIVE             = 0x350,
        FIS_IRQ_CAUSE           = 0x364,
        FIS_IRQ_CAUSE_AN        = (1 << 9),     /* async notification */

        LTMODE                  = 0x30c,        /* requires read-after-write */
        LTMODE_BIT8             = (1 << 8),     /* unknown, but necessary */

        PHY_MODE2               = 0x330,
        PHY_MODE3               = 0x310,

        PHY_MODE4               = 0x314,        /* requires read-after-write */
        PHY_MODE4_CFG_MASK      = 0x00000003,   /* phy internal config field */
        PHY_MODE4_CFG_VALUE     = 0x00000001,   /* phy internal config field */
        PHY_MODE4_RSVD_ZEROS    = 0x5de3fffa,   /* Gen2e always write zeros */
        PHY_MODE4_RSVD_ONES     = 0x00000005,   /* Gen2e always write ones */

        SATA_IFCTL              = 0x344,
        SATA_TESTCTL            = 0x348,
        SATA_IFSTAT             = 0x34c,
        VENDOR_UNIQUE_FIS       = 0x35c,

        FISCFG                  = 0x360,
        FISCFG_WAIT_DEV_ERR     = (1 << 8),     /* wait for host on DevErr */
        FISCFG_SINGLE_SYNC      = (1 << 16),    /* SYNC on DMA activation */

        PHY_MODE9_GEN2          = 0x398,
        PHY_MODE9_GEN1          = 0x39c,
        PHYCFG_OFS              = 0x3a0,        /* only in 65n devices */

        MV5_PHY_MODE            = 0x74,
        MV5_LTMODE              = 0x30,
        MV5_PHY_CTL             = 0x0C,
        SATA_IFCFG              = 0x050,

        MV_M2_PREAMP_MASK       = 0x7e0,

        /* Port registers */
        EDMA_CFG                = 0,
        EDMA_CFG_Q_DEPTH        = 0x1f,         /* max device queue depth */
        EDMA_CFG_NCQ            = (1 << 5),     /* for R/W FPDMA queued */
        EDMA_CFG_NCQ_GO_ON_ERR  = (1 << 14),    /* continue on error */
        EDMA_CFG_RD_BRST_EXT    = (1 << 11),    /* read burst 512B */
        EDMA_CFG_WR_BUFF_LEN    = (1 << 13),    /* write buffer 512B */
        EDMA_CFG_EDMA_FBS       = (1 << 16),    /* EDMA FIS-Based Switching */
        EDMA_CFG_FBS            = (1 << 26),    /* FIS-Based Switching */

        EDMA_ERR_IRQ_CAUSE      = 0x8,
        EDMA_ERR_IRQ_MASK       = 0xc,
        EDMA_ERR_D_PAR          = (1 << 0),     /* UDMA data parity err */
        EDMA_ERR_PRD_PAR        = (1 << 1),     /* UDMA PRD parity err */
        EDMA_ERR_DEV            = (1 << 2),     /* device error */
        EDMA_ERR_DEV_DCON       = (1 << 3),     /* device disconnect */
        EDMA_ERR_DEV_CON        = (1 << 4),     /* device connected */
        EDMA_ERR_SERR           = (1 << 5),     /* SError bits [WBDST] raised */
        EDMA_ERR_SELF_DIS       = (1 << 7),     /* Gen II/IIE self-disable */
        EDMA_ERR_SELF_DIS_5     = (1 << 8),     /* Gen I self-disable */
        EDMA_ERR_BIST_ASYNC     = (1 << 8),     /* BIST FIS or Async Notify */
        EDMA_ERR_TRANS_IRQ_7    = (1 << 8),     /* Gen IIE transprt layer irq */
        EDMA_ERR_CRQB_PAR       = (1 << 9),     /* CRQB parity error */
        EDMA_ERR_CRPB_PAR       = (1 << 10),    /* CRPB parity error */
        EDMA_ERR_INTRL_PAR      = (1 << 11),    /* internal parity error */
        EDMA_ERR_IORDY          = (1 << 12),    /* IORdy timeout */

        EDMA_ERR_LNK_CTRL_RX    = (0xf << 13),  /* link ctrl rx error */
        EDMA_ERR_LNK_CTRL_RX_0  = (1 << 13),    /* transient: CRC err */
        EDMA_ERR_LNK_CTRL_RX_1  = (1 << 14),    /* transient: FIFO err */
        EDMA_ERR_LNK_CTRL_RX_2  = (1 << 15),    /* fatal: caught SYNC */
        EDMA_ERR_LNK_CTRL_RX_3  = (1 << 16),    /* transient: FIS rx err */

        EDMA_ERR_LNK_DATA_RX    = (0xf << 17),  /* link data rx error */

        EDMA_ERR_LNK_CTRL_TX    = (0x1f << 21), /* link ctrl tx error */
        EDMA_ERR_LNK_CTRL_TX_0  = (1 << 21),    /* transient: CRC err */
        EDMA_ERR_LNK_CTRL_TX_1  = (1 << 22),    /* transient: FIFO err */
        EDMA_ERR_LNK_CTRL_TX_2  = (1 << 23),    /* transient: caught SYNC */
        EDMA_ERR_LNK_CTRL_TX_3  = (1 << 24),    /* transient: caught DMAT */
        EDMA_ERR_LNK_CTRL_TX_4  = (1 << 25),    /* transient: FIS collision */

        EDMA_ERR_LNK_DATA_TX    = (0x1f << 26), /* link data tx error */

        EDMA_ERR_TRANS_PROTO    = (1 << 31),    /* transport protocol error */
        EDMA_ERR_OVERRUN_5      = (1 << 5),
        EDMA_ERR_UNDERRUN_5     = (1 << 6),

        EDMA_ERR_IRQ_TRANSIENT  = EDMA_ERR_LNK_CTRL_RX_0 |
                                  EDMA_ERR_LNK_CTRL_RX_1 |
                                  EDMA_ERR_LNK_CTRL_RX_3 |
                                  EDMA_ERR_LNK_CTRL_TX,

        EDMA_EH_FREEZE          = EDMA_ERR_D_PAR |
                                  EDMA_ERR_PRD_PAR |
                                  EDMA_ERR_DEV_DCON |
                                  EDMA_ERR_DEV_CON |
                                  EDMA_ERR_SERR |
                                  EDMA_ERR_SELF_DIS |
                                  EDMA_ERR_CRQB_PAR |
                                  EDMA_ERR_CRPB_PAR |
                                  EDMA_ERR_INTRL_PAR |
                                  EDMA_ERR_IORDY |
                                  EDMA_ERR_LNK_CTRL_RX_2 |
                                  EDMA_ERR_LNK_DATA_RX |
                                  EDMA_ERR_LNK_DATA_TX |
                                  EDMA_ERR_TRANS_PROTO,

        EDMA_EH_FREEZE_5        = EDMA_ERR_D_PAR |
                                  EDMA_ERR_PRD_PAR |
                                  EDMA_ERR_DEV_DCON |
                                  EDMA_ERR_DEV_CON |
                                  EDMA_ERR_OVERRUN_5 |
                                  EDMA_ERR_UNDERRUN_5 |
                                  EDMA_ERR_SELF_DIS_5 |
                                  EDMA_ERR_CRQB_PAR |
                                  EDMA_ERR_CRPB_PAR |
                                  EDMA_ERR_INTRL_PAR |
                                  EDMA_ERR_IORDY,

        EDMA_REQ_Q_BASE_HI      = 0x10,
        EDMA_REQ_Q_IN_PTR       = 0x14,         /* also contains BASE_LO */

        EDMA_REQ_Q_OUT_PTR      = 0x18,
        EDMA_REQ_Q_PTR_SHIFT    = 5,

        EDMA_RSP_Q_BASE_HI      = 0x1c,
        EDMA_RSP_Q_IN_PTR       = 0x20,
        EDMA_RSP_Q_OUT_PTR      = 0x24,         /* also contains BASE_LO */
        EDMA_RSP_Q_PTR_SHIFT    = 3,

        EDMA_CMD                = 0x28,         /* EDMA command register */
        EDMA_EN                 = (1 << 0),     /* enable EDMA */
        EDMA_DS                 = (1 << 1),     /* disable EDMA; self-negated */
        EDMA_RESET              = (1 << 2),     /* reset eng/trans/link/phy */

        EDMA_STATUS             = 0x30,         /* EDMA engine status */
        EDMA_STATUS_CACHE_EMPTY = (1 << 6),     /* GenIIe command cache empty */
        EDMA_STATUS_IDLE        = (1 << 7),     /* GenIIe EDMA enabled/idle */

        EDMA_IORDY_TMOUT        = 0x34,
        EDMA_ARB_CFG            = 0x38,

        EDMA_HALTCOND           = 0x60,         /* GenIIe halt conditions */
        EDMA_UNKNOWN_RSVD       = 0x6C,         /* GenIIe unknown/reserved */

        BMDMA_CMD               = 0x224,        /* bmdma command register */
        BMDMA_STATUS            = 0x228,        /* bmdma status register */
        BMDMA_PRD_LOW           = 0x22c,        /* bmdma PRD addr 31:0 */
        BMDMA_PRD_HIGH          = 0x230,        /* bmdma PRD addr 63:32 */

        /* Host private flags (hp_flags) */
        MV_HP_FLAG_MSI          = (1 << 0),
        MV_HP_ERRATA_50XXB0     = (1 << 1),
        MV_HP_ERRATA_50XXB2     = (1 << 2),
        MV_HP_ERRATA_60X1B2     = (1 << 3),
        MV_HP_ERRATA_60X1C0     = (1 << 4),
        MV_HP_GEN_I             = (1 << 6),     /* Generation I: 50xx */
        MV_HP_GEN_II            = (1 << 7),     /* Generation II: 60xx */
        MV_HP_GEN_IIE           = (1 << 8),     /* Generation IIE: 6042/7042 */
        MV_HP_PCIE              = (1 << 9),     /* PCIe bus/regs: 7042 */
        MV_HP_CUT_THROUGH       = (1 << 10),    /* can use EDMA cut-through */
        MV_HP_FLAG_SOC          = (1 << 11),    /* SystemOnChip, no PCI */
        MV_HP_QUIRK_LED_BLINK_EN = (1 << 12),   /* is led blinking enabled? */

        /* Port private flags (pp_flags) */
        MV_PP_FLAG_EDMA_EN      = (1 << 0),     /* is EDMA engine enabled? */
        MV_PP_FLAG_NCQ_EN       = (1 << 1),     /* is EDMA set up for NCQ? */
        MV_PP_FLAG_FBS_EN       = (1 << 2),     /* is EDMA set up for FBS? */
        MV_PP_FLAG_DELAYED_EH   = (1 << 3),     /* delayed dev err handling */
        MV_PP_FLAG_FAKE_ATA_BUSY = (1 << 4),    /* ignore initial ATA_DRDY */
};

#define IS_GEN_I(hpriv) ((hpriv)->hp_flags & MV_HP_GEN_I)
#define IS_GEN_II(hpriv) ((hpriv)->hp_flags & MV_HP_GEN_II)
#define IS_GEN_IIE(hpriv) ((hpriv)->hp_flags & MV_HP_GEN_IIE)
#define IS_PCIE(hpriv) ((hpriv)->hp_flags & MV_HP_PCIE)
#define IS_SOC(hpriv) ((hpriv)->hp_flags & MV_HP_FLAG_SOC)

#define WINDOW_CTRL(i)          (0x20030 + ((i) << 4))
#define WINDOW_BASE(i)          (0x20034 + ((i) << 4))

enum {
        /* DMA boundary 0xffff is required by the s/g splitting
         * we need on /length/ in mv_fill-sg().
         */
        MV_DMA_BOUNDARY         = 0xffffU,

        /* mask of register bits containing lower 32 bits
         * of EDMA request queue DMA address
         */
        EDMA_REQ_Q_BASE_LO_MASK = 0xfffffc00U,

        /* ditto, for response queue */
        EDMA_RSP_Q_BASE_LO_MASK = 0xffffff00U,
};

enum chip_type {
        chip_504x,
        chip_508x,
        chip_5080,
        chip_604x,
        chip_608x,
        chip_6042,
        chip_7042,
        chip_soc,
};

/* Command ReQuest Block: 32B */
struct mv_crqb {
        __le32                  sg_addr;
        __le32                  sg_addr_hi;
        __le16                  ctrl_flags;
        __le16                  ata_cmd[11];
};

struct mv_crqb_iie {
        __le32                  addr;
        __le32                  addr_hi;
        __le32                  flags;
        __le32                  len;
        __le32                  ata_cmd[4];
};

/* Command ResPonse Block: 8B */
struct mv_crpb {
        __le16                  id;
        __le16                  flags;
        __le32                  tmstmp;
};

/* EDMA Physical Region Descriptor (ePRD); A.K.A. SG */
struct mv_sg {
        __le32                  addr;
        __le32                  flags_size;
        __le32                  addr_hi;
        __le32                  reserved;
};

/*
 * We keep a local cache of a few frequently accessed port
 * registers here, to avoid having to read them (very slow)
 * when switching between EDMA and non-EDMA modes.
 */
struct mv_cached_regs {
        u32                     fiscfg;
        u32                     ltmode;
        u32                     haltcond;
        u32                     unknown_rsvd;
};

struct mv_port_priv {
        struct mv_crqb          *crqb;
        dma_addr_t              crqb_dma;
        struct mv_crpb          *crpb;
        dma_addr_t              crpb_dma;
        struct mv_sg            *sg_tbl[MV_MAX_Q_DEPTH];
        dma_addr_t              sg_tbl_dma[MV_MAX_Q_DEPTH];

        unsigned int            req_idx;
        unsigned int            resp_idx;

        u32                     pp_flags;
        struct mv_cached_regs   cached;
        unsigned int            delayed_eh_pmp_map;
};

struct mv_port_signal {
        u32                     amps;
        u32                     pre;
};

struct mv_host_priv {
        u32                     hp_flags;
        u32                     main_irq_mask;
        struct mv_port_signal   signal[8];
        const struct mv_hw_ops  *ops;
        int                     n_ports;
        void __iomem            *base;
        void __iomem            *main_irq_cause_addr;
        void __iomem            *main_irq_mask_addr;
        u32                     irq_cause_offset;
        u32                     irq_mask_offset;
        u32                     unmask_all_irqs;
        /*
         * These consistent DMA memory pools give us guaranteed
         * alignment for hardware-accessed data structures,
         * and less memory waste in accomplishing the alignment.
         */
        struct dma_pool         *crqb_pool;
        struct dma_pool         *crpb_pool;
        struct dma_pool         *sg_tbl_pool;
};

struct mv_hw_ops {
        void (*phy_errata)(struct mv_host_priv *hpriv, void __iomem *mmio,
                           unsigned int port);
        void (*enable_leds)(struct mv_host_priv *hpriv, void __iomem *mmio);
        void (*read_preamp)(struct mv_host_priv *hpriv, int idx,
                           void __iomem *mmio);
        int (*reset_hc)(struct mv_host_priv *hpriv, void __iomem *mmio,
                        unsigned int n_hc);
        void (*reset_flash)(struct mv_host_priv *hpriv, void __iomem *mmio);
        void (*reset_bus)(struct ata_host *host, void __iomem *mmio);
};

static int mv_scr_read(struct ata_link *link, unsigned int sc_reg_in, u32 *val);
static int mv_scr_write(struct ata_link *link, unsigned int sc_reg_in, u32 val);
static int mv5_scr_read(struct ata_link *link, unsigned int sc_reg_in, u32 *val);
static int mv5_scr_write(struct ata_link *link, unsigned int sc_reg_in, u32 val);
static int mv_port_start(struct ata_port *ap);
static void mv_port_stop(struct ata_port *ap);
static int mv_qc_defer(struct ata_queued_cmd *qc);
static void mv_qc_prep(struct ata_queued_cmd *qc);
static void mv_qc_prep_iie(struct ata_queued_cmd *qc);
static unsigned int mv_qc_issue(struct ata_queued_cmd *qc);
static int mv_hardreset(struct ata_link *link, unsigned int *class,
                        unsigned long deadline);
static void mv_eh_freeze(struct ata_port *ap);
static void mv_eh_thaw(struct ata_port *ap);
static void mv6_dev_config(struct ata_device *dev);

static void mv5_phy_errata(struct mv_host_priv *hpriv, void __iomem *mmio,
                           unsigned int port);
static void mv5_enable_leds(struct mv_host_priv *hpriv, void __iomem *mmio);
static void mv5_read_preamp(struct mv_host_priv *hpriv, int idx,
                           void __iomem *mmio);
static int mv5_reset_hc(struct mv_host_priv *hpriv, void __iomem *mmio,
                        unsigned int n_hc);
static void mv5_reset_flash(struct mv_host_priv *hpriv, void __iomem *mmio);
static void mv5_reset_bus(struct ata_host *host, void __iomem *mmio);

static void mv6_phy_errata(struct mv_host_priv *hpriv, void __iomem *mmio,
                           unsigned int port);
static void mv6_enable_leds(struct mv_host_priv *hpriv, void __iomem *mmio);
static void mv6_read_preamp(struct mv_host_priv *hpriv, int idx,
                           void __iomem *mmio);
static int mv6_reset_hc(struct mv_host_priv *hpriv, void __iomem *mmio,
                        unsigned int n_hc);
static void mv6_reset_flash(struct mv_host_priv *hpriv, void __iomem *mmio);
static void mv_soc_enable_leds(struct mv_host_priv *hpriv,
                                      void __iomem *mmio);
static void mv_soc_read_preamp(struct mv_host_priv *hpriv, int idx,
                                      void __iomem *mmio);
static int mv_soc_reset_hc(struct mv_host_priv *hpriv,
                                  void __iomem *mmio, unsigned int n_hc);
static void mv_soc_reset_flash(struct mv_host_priv *hpriv,
                                      void __iomem *mmio);
static void mv_soc_reset_bus(struct ata_host *host, void __iomem *mmio);
static void mv_soc_65n_phy_errata(struct mv_host_priv *hpriv,
                                  void __iomem *mmio, unsigned int port);
static void mv_reset_pci_bus(struct ata_host *host, void __iomem *mmio);
static void mv_reset_channel(struct mv_host_priv *hpriv, void __iomem *mmio,
                             unsigned int port_no);
static int mv_stop_edma(struct ata_port *ap);
static int mv_stop_edma_engine(void __iomem *port_mmio);
static void mv_edma_cfg(struct ata_port *ap, int want_ncq, int want_edma);

static void mv_pmp_select(struct ata_port *ap, int pmp);
static int mv_pmp_hardreset(struct ata_link *link, unsigned int *class,
                                unsigned long deadline);
static int  mv_softreset(struct ata_link *link, unsigned int *class,
                                unsigned long deadline);
static void mv_pmp_error_handler(struct ata_port *ap);
static void mv_process_crpb_entries(struct ata_port *ap,
                                        struct mv_port_priv *pp);

static void mv_sff_irq_clear(struct ata_port *ap);
static int mv_check_atapi_dma(struct ata_queued_cmd *qc);
static void mv_bmdma_setup(struct ata_queued_cmd *qc);
static void mv_bmdma_start(struct ata_queued_cmd *qc);
static void mv_bmdma_stop(struct ata_queued_cmd *qc);
static u8   mv_bmdma_status(struct ata_port *ap);
static u8 mv_sff_check_status(struct ata_port *ap);

/* .sg_tablesize is (MV_MAX_SG_CT / 2) in the structures below
 * because we have to allow room for worst case splitting of
 * PRDs for 64K boundaries in mv_fill_sg().
 */
static struct scsi_host_template mv5_sht = {
        ATA_BASE_SHT(DRV_NAME),
        .sg_tablesize           = MV_MAX_SG_CT / 2,
        .dma_boundary           = MV_DMA_BOUNDARY,
};

static struct scsi_host_template mv6_sht = {
        ATA_NCQ_SHT(DRV_NAME),
        .can_queue              = MV_MAX_Q_DEPTH - 1,
        .sg_tablesize           = MV_MAX_SG_CT / 2,
        .dma_boundary           = MV_DMA_BOUNDARY,
};

static struct ata_port_operations mv5_ops = {
        .inherits               = &ata_sff_port_ops,

        .lost_interrupt         = ATA_OP_NULL,

        .qc_defer               = mv_qc_defer,
        .qc_prep                = mv_qc_prep,
        .qc_issue               = mv_qc_issue,

        .freeze                 = mv_eh_freeze,
        .thaw                   = mv_eh_thaw,
        .hardreset              = mv_hardreset,
        .error_handler          = ata_std_error_handler, /* avoid SFF EH */
        .post_internal_cmd      = ATA_OP_NULL,

        .scr_read               = mv5_scr_read,
        .scr_write              = mv5_scr_write,

        .port_start             = mv_port_start,
        .port_stop              = mv_port_stop,
};

static struct ata_port_operations mv6_ops = {
        .inherits               = &mv5_ops,
        .dev_config             = mv6_dev_config,
        .scr_read               = mv_scr_read,
        .scr_write              = mv_scr_write,

        .pmp_hardreset          = mv_pmp_hardreset,
        .pmp_softreset          = mv_softreset,
        .softreset              = mv_softreset,
        .error_handler          = mv_pmp_error_handler,

        .sff_check_status       = mv_sff_check_status,
        .sff_irq_clear          = mv_sff_irq_clear,
        .check_atapi_dma        = mv_check_atapi_dma,
        .bmdma_setup            = mv_bmdma_setup,
        .bmdma_start            = mv_bmdma_start,
        .bmdma_stop             = mv_bmdma_stop,
        .bmdma_status           = mv_bmdma_status,
};

static struct ata_port_operations mv_iie_ops = {
        .inherits               = &mv6_ops,
        .dev_config             = ATA_OP_NULL,
        .qc_prep                = mv_qc_prep_iie,
};

static const struct ata_port_info mv_port_info[] = {
        {  /* chip_504x */
                .flags          = MV_GEN_I_FLAGS,
                .pio_mask       = ATA_PIO4,
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &mv5_ops,
        },
        {  /* chip_508x */
                .flags          = MV_GEN_I_FLAGS | MV_FLAG_DUAL_HC,
                .pio_mask       = ATA_PIO4,
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &mv5_ops,
        },
        {  /* chip_5080 */
                .flags          = MV_GEN_I_FLAGS | MV_FLAG_DUAL_HC,
                .pio_mask       = ATA_PIO4,
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &mv5_ops,
        },
        {  /* chip_604x */
                .flags          = MV_GEN_II_FLAGS,
                .pio_mask       = ATA_PIO4,
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &mv6_ops,
        },
        {  /* chip_608x */
                .flags          = MV_GEN_II_FLAGS | MV_FLAG_DUAL_HC,
                .pio_mask       = ATA_PIO4,
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &mv6_ops,
        },
        {  /* chip_6042 */
                .flags          = MV_GEN_IIE_FLAGS,
                .pio_mask       = ATA_PIO4,
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &mv_iie_ops,
        },
        {  /* chip_7042 */
                .flags          = MV_GEN_IIE_FLAGS,
                .pio_mask       = ATA_PIO4,
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &mv_iie_ops,
        },
        {  /* chip_soc */
                .flags          = MV_GEN_IIE_FLAGS,
                .pio_mask       = ATA_PIO4,
                .udma_mask      = ATA_UDMA6,
                .port_ops       = &mv_iie_ops,
        },
};

static const struct pci_device_id mv_pci_tbl[] = {
        { PCI_VDEVICE(MARVELL, 0x5040), chip_504x },
        { PCI_VDEVICE(MARVELL, 0x5041), chip_504x },
        { PCI_VDEVICE(MARVELL, 0x5080), chip_5080 },
        { PCI_VDEVICE(MARVELL, 0x5081), chip_508x },
        /* RocketRAID 1720/174x have different identifiers */
        { PCI_VDEVICE(TTI, 0x1720), chip_6042 },
        { PCI_VDEVICE(TTI, 0x1740), chip_6042 },
        { PCI_VDEVICE(TTI, 0x1742), chip_6042 },

        { PCI_VDEVICE(MARVELL, 0x6040), chip_604x },
        { PCI_VDEVICE(MARVELL, 0x6041), chip_604x },
        { PCI_VDEVICE(MARVELL, 0x6042), chip_6042 },
        { PCI_VDEVICE(MARVELL, 0x6080), chip_608x },
        { PCI_VDEVICE(MARVELL, 0x6081), chip_608x },

        { PCI_VDEVICE(ADAPTEC2, 0x0241), chip_604x },

        /* Adaptec 1430SA */
        { PCI_VDEVICE(ADAPTEC2, 0x0243), chip_7042 },

        /* Marvell 7042 support */
        { PCI_VDEVICE(MARVELL, 0x7042), chip_7042 },

        /* Highpoint RocketRAID PCIe series */
        { PCI_VDEVICE(TTI, 0x2300), chip_7042 },
        { PCI_VDEVICE(TTI, 0x2310), chip_7042 },

        { }                     /* terminate list */
};

static const struct mv_hw_ops mv5xxx_ops = {
        .phy_errata             = mv5_phy_errata,
        .enable_leds            = mv5_enable_leds,
        .read_preamp            = mv5_read_preamp,
        .reset_hc               = mv5_reset_hc,
        .reset_flash            = mv5_reset_flash,
        .reset_bus              = mv5_reset_bus,
};

static const struct mv_hw_ops mv6xxx_ops = {
        .phy_errata             = mv6_phy_errata,
        .enable_leds            = mv6_enable_leds,
        .read_preamp            = mv6_read_preamp,
        .reset_hc               = mv6_reset_hc,
        .reset_flash            = mv6_reset_flash,
        .reset_bus              = mv_reset_pci_bus,
};

static const struct mv_hw_ops mv_soc_ops = {
        .phy_errata             = mv6_phy_errata,
        .enable_leds            = mv_soc_enable_leds,
        .read_preamp            = mv_soc_read_preamp,
        .reset_hc               = mv_soc_reset_hc,
        .reset_flash            = mv_soc_reset_flash,
        .reset_bus              = mv_soc_reset_bus,
};

static const struct mv_hw_ops mv_soc_65n_ops = {
        .phy_errata             = mv_soc_65n_phy_errata,
        .enable_leds            = mv_soc_enable_leds,
        .reset_hc               = mv_soc_reset_hc,
        .reset_flash            = mv_soc_reset_flash,
        .reset_bus              = mv_soc_reset_bus,
};

/*
 * Functions
 */

static inline void writelfl(unsigned long data, void __iomem *addr)
{
        writel(data, addr);
        (void) readl(addr);     /* flush to avoid PCI posted write */
}

static inline unsigned int mv_hc_from_port(unsigned int port)
{
        return port >> MV_PORT_HC_SHIFT;
}

static inline unsigned int mv_hardport_from_port(unsigned int port)
{
        return port & MV_PORT_MASK;
}

/*
 * Consolidate some rather tricky bit shift calculations.
 * This is hot-path stuff, so not a function.
 * Simple code, with two return values, so macro rather than inline.
 *
 * port is the sole input, in range 0..7.
 * shift is one output, for use with main_irq_cause / main_irq_mask registers.
 * hardport is the other output, in range 0..3.
 *
 * Note that port and hardport may be the same variable in some cases.
 */
#define MV_PORT_TO_SHIFT_AND_HARDPORT(port, shift, hardport)    \
{                                                               \
        shift    = mv_hc_from_port(port) * HC_SHIFT;            \
        hardport = mv_hardport_from_port(port);                 \
        shift   += hardport * 2;                                \
}

static inline void __iomem *mv_hc_base(void __iomem *base, unsigned int hc)
{
        return (base + SATAHC0_REG_BASE + (hc * MV_SATAHC_REG_SZ));
}

static inline void __iomem *mv_hc_base_from_port(void __iomem *base,
                                                 unsigned int port)
{
        return mv_hc_base(base, mv_hc_from_port(port));
}

static inline void __iomem *mv_port_base(void __iomem *base, unsigned int port)
{
        return  mv_hc_base_from_port(base, port) +
                MV_SATAHC_ARBTR_REG_SZ +
                (mv_hardport_from_port(port) * MV_PORT_REG_SZ);
}

static void __iomem *mv5_phy_base(void __iomem *mmio, unsigned int port)
{
        void __iomem *hc_mmio = mv_hc_base_from_port(mmio, port);
        unsigned long ofs = (mv_hardport_from_port(port) + 1) * 0x100UL;

        return hc_mmio + ofs;
}

static inline void __iomem *mv_host_base(struct ata_host *host)
{
        struct mv_host_priv *hpriv = host->private_data;
        return hpriv->base;
}

static inline void __iomem *mv_ap_base(struct ata_port *ap)
{
        return mv_port_base(mv_host_base(ap->host), ap->port_no);
}

static inline int mv_get_hc_count(unsigned long port_flags)
{
        return ((port_flags & MV_FLAG_DUAL_HC) ? 2 : 1);
}

/**
 *      mv_save_cached_regs - (re-)initialize cached port registers
 *      @ap: the port whose registers we are caching
 *
 *      Initialize the local cache of port registers,
 *      so that reading them over and over again can
 *      be avoided on the hotter paths of this driver.
 *      This saves a few microseconds each time we switch
 *      to/from EDMA mode to perform (eg.) a drive cache flush.
 */
static void mv_save_cached_regs(struct ata_port *ap)
{
        void __iomem *port_mmio = mv_ap_base(ap);
        struct mv_port_priv *pp = ap->private_data;

        pp->cached.fiscfg = readl(port_mmio + FISCFG);
        pp->cached.ltmode = readl(port_mmio + LTMODE);
        pp->cached.haltcond = readl(port_mmio + EDMA_HALTCOND);
        pp->cached.unknown_rsvd = readl(port_mmio + EDMA_UNKNOWN_RSVD);
}

/**
 *      mv_write_cached_reg - write to a cached port register
 *      @addr: hardware address of the register
 *      @old: pointer to cached value of the register
 *      @new: new value for the register
 *
 *      Write a new value to a cached register,
 *      but only if the value is different from before.
 */
static inline void mv_write_cached_reg(void __iomem *addr, u32 *old, u32 new)
{
        if (new != *old) {
                unsigned long laddr;
                *old = new;
                /*
                 * Workaround for 88SX60x1-B2 FEr SATA#13:
                 * Read-after-write is needed to prevent generating 64-bit
                 * write cycles on the PCI bus for SATA interface registers
                 * at offsets ending in 0x4 or 0xc.
                 *
                 * Looks like a lot of fuss, but it avoids an unnecessary
                 * +1 usec read-after-write delay for unaffected registers.
                 */
                laddr = (long)addr & 0xffff;
                if (laddr >= 0x300 && laddr <= 0x33c) {
                        laddr &= 0x000f;
                        if (laddr == 0x4 || laddr == 0xc) {
                                writelfl(new, addr); /* read after write */
                                return;
                        }
                }
                writel(new, addr); /* unaffected by the errata */
        }
}

static void mv_set_edma_ptrs(void __iomem *port_mmio,
                             struct mv_host_priv *hpriv,
                             struct mv_port_priv *pp)
{
        u32 index;

        /*
         * initialize request queue
         */
        pp->req_idx &= MV_MAX_Q_DEPTH_MASK;     /* paranoia */
        index = pp->req_idx << EDMA_REQ_Q_PTR_SHIFT;

        WARN_ON(pp->crqb_dma & 0x3ff);
        writel((pp->crqb_dma >> 16) >> 16, port_mmio + EDMA_REQ_Q_BASE_HI);
        writelfl((pp->crqb_dma & EDMA_REQ_Q_BASE_LO_MASK) | index,
                 port_mmio + EDMA_REQ_Q_IN_PTR);
        writelfl(index, port_mmio + EDMA_REQ_Q_OUT_PTR);

        /*
         * initialize response queue
         */
        pp->resp_idx &= MV_MAX_Q_DEPTH_MASK;    /* paranoia */
        index = pp->resp_idx << EDMA_RSP_Q_PTR_SHIFT;

        WARN_ON(pp->crpb_dma & 0xff);
        writel((pp->crpb_dma >> 16) >> 16, port_mmio + EDMA_RSP_Q_BASE_HI);
        writelfl(index, port_mmio + EDMA_RSP_Q_IN_PTR);
        writelfl((pp->crpb_dma & EDMA_RSP_Q_BASE_LO_MASK) | index,
                 port_mmio + EDMA_RSP_Q_OUT_PTR);
}

static void mv_write_main_irq_mask(u32 mask, struct mv_host_priv *hpriv)
{
        /*
         * When writing to the main_irq_mask in hardware,
         * we must ensure exclusivity between the interrupt coalescing bits
         * and the corresponding individual port DONE_IRQ bits.
         *
         * Note that this register is really an "IRQ enable" register,
         * not an "IRQ mask" register as Marvell's naming might suggest.
         */

        if (mask & (ALL_PORTS_COAL_DONE | PORTS_0_3_COAL_DONE))
                mask &= ~DONE_IRQ_0_3;
        if (mask & (ALL_PORTS_COAL_DONE | PORTS_4_7_COAL_DONE))
                mask &= ~DONE_IRQ_4_7;
        writelfl(mask, hpriv->main_irq_mask_addr);
}

static void mv_set_main_irq_mask(struct ata_host *host,
                                 u32 disable_bits, u32 enable_bits)
{
        struct mv_host_priv *hpriv = host->private_data;
        u32 old_mask, new_mask;

        old_mask = hpriv->main_irq_mask;
        new_mask = (old_mask & ~disable_bits) | enable_bits;
        if (new_mask != old_mask) {
                hpriv->main_irq_mask = new_mask;
                mv_write_main_irq_mask(new_mask, hpriv);
        }
}

static void mv_enable_port_irqs(struct ata_port *ap,
                                     unsigned int port_bits)
{
        unsigned int shift, hardport, port = ap->port_no;
        u32 disable_bits, enable_bits;

        MV_PORT_TO_SHIFT_AND_HARDPORT(port, shift, hardport);

        disable_bits = (DONE_IRQ | ERR_IRQ) << shift;
        enable_bits  = port_bits << shift;
        mv_set_main_irq_mask(ap->host, disable_bits, enable_bits);
}

static void mv_clear_and_enable_port_irqs(struct ata_port *ap,
                                          void __iomem *port_mmio,
                                          unsigned int port_irqs)
{
        struct mv_host_priv *hpriv = ap->host->private_data;
        int hardport = mv_hardport_from_port(ap->port_no);
        void __iomem *hc_mmio = mv_hc_base_from_port(
                                mv_host_base(ap->host), ap->port_no);
        u32 hc_irq_cause;

        /* clear EDMA event indicators, if any */
        writelfl(0, port_mmio + EDMA_ERR_IRQ_CAUSE);

        /* clear pending irq events */
        hc_irq_cause = ~((DEV_IRQ | DMA_IRQ) << hardport);
        writelfl(hc_irq_cause, hc_mmio + HC_IRQ_CAUSE);

        /* clear FIS IRQ Cause */
        if (IS_GEN_IIE(hpriv))
                writelfl(0, port_mmio + FIS_IRQ_CAUSE);

        mv_enable_port_irqs(ap, port_irqs);
}

static void mv_set_irq_coalescing(struct ata_host *host,
                                  unsigned int count, unsigned int usecs)
{
        struct mv_host_priv *hpriv = host->private_data;
        void __iomem *mmio = hpriv->base, *hc_mmio;
        u32 coal_enable = 0;
        unsigned long flags;
        unsigned int clks, is_dual_hc = hpriv->n_ports > MV_PORTS_PER_HC;
        const u32 coal_disable = PORTS_0_3_COAL_DONE | PORTS_4_7_COAL_DONE |
                                                        ALL_PORTS_COAL_DONE;

        /* Disable IRQ coalescing if either threshold is zero */
        if (!usecs || !count) {
                clks = count = 0;
        } else {
                /* Respect maximum limits of the hardware */
                clks = usecs * COAL_CLOCKS_PER_USEC;
                if (clks > MAX_COAL_TIME_THRESHOLD)
                        clks = MAX_COAL_TIME_THRESHOLD;
                if (count > MAX_COAL_IO_COUNT)
                        count = MAX_COAL_IO_COUNT;
        }

        spin_lock_irqsave(&host->lock, flags);
        mv_set_main_irq_mask(host, coal_disable, 0);

        if (is_dual_hc && !IS_GEN_I(hpriv)) {
                /*
                 * GEN_II/GEN_IIE with dual host controllers:
                 * one set of global thresholds for the entire chip.
                 */
                writel(clks,  mmio + IRQ_COAL_TIME_THRESHOLD);
                writel(count, mmio + IRQ_COAL_IO_THRESHOLD);
                /* clear leftover coal IRQ bit */
                writel(~ALL_PORTS_COAL_IRQ, mmio + IRQ_COAL_CAUSE);
                if (count)
                        coal_enable = ALL_PORTS_COAL_DONE;
                clks = count = 0; /* force clearing of regular regs below */
        }

        /*
         * All chips: independent thresholds for each HC on the chip.
         */
        hc_mmio = mv_hc_base_from_port(mmio, 0);
        writel(clks,  hc_mmio + HC_IRQ_COAL_TIME_THRESHOLD);
        writel(count, hc_mmio + HC_IRQ_COAL_IO_THRESHOLD);
        writel(~HC_COAL_IRQ, hc_mmio + HC_IRQ_CAUSE);
        if (count)
                coal_enable |= PORTS_0_3_COAL_DONE;
        if (is_dual_hc) {
                hc_mmio = mv_hc_base_from_port(mmio, MV_PORTS_PER_HC);
                writel(clks,  hc_mmio + HC_IRQ_COAL_TIME_THRESHOLD);
                writel(count, hc_mmio + HC_IRQ_COAL_IO_THRESHOLD);
                writel(~HC_COAL_IRQ, hc_mmio + HC_IRQ_CAUSE);
                if (count)
                        coal_enable |= PORTS_4_7_COAL_DONE;
        }

        mv_set_main_irq_mask(host, 0, coal_enable);
        spin_unlock_irqrestore(&host->lock, flags);
}

/**
 *      mv_start_edma - Enable eDMA engine
 *      @base: port base address
 *      @pp: port private data
 *
 *      Verify the local cache of the eDMA state is accurate with a
 *      WARN_ON.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static void mv_start_edma(struct ata_port *ap, void __iomem *port_mmio,
                         struct mv_port_priv *pp, u8 protocol)
{
        int want_ncq = (protocol == ATA_PROT_NCQ);

        if (pp->pp_flags & MV_PP_FLAG_EDMA_EN) {
                int using_ncq = ((pp->pp_flags & MV_PP_FLAG_NCQ_EN) != 0);
                if (want_ncq != using_ncq)
                        mv_stop_edma(ap);
        }
        if (!(pp->pp_flags & MV_PP_FLAG_EDMA_EN)) {
                struct mv_host_priv *hpriv = ap->host->private_data;

                mv_edma_cfg(ap, want_ncq, 1);

                mv_set_edma_ptrs(port_mmio, hpriv, pp);
                mv_clear_and_enable_port_irqs(ap, port_mmio, DONE_IRQ|ERR_IRQ);

                writelfl(EDMA_EN, port_mmio + EDMA_CMD);
                pp->pp_flags |= MV_PP_FLAG_EDMA_EN;
        }
}

static void mv_wait_for_edma_empty_idle(struct ata_port *ap)
{
        void __iomem *port_mmio = mv_ap_base(ap);
        const u32 empty_idle = (EDMA_STATUS_CACHE_EMPTY | EDMA_STATUS_IDLE);
        const int per_loop = 5, timeout = (15 * 1000 / per_loop);
        int i;

        /*
         * Wait for the EDMA engine to finish transactions in progress.
         * No idea what a good "timeout" value might be, but measurements
         * indicate that it often requires hundreds of microseconds
         * with two drives in-use.  So we use the 15msec value above
         * as a rough guess at what even more drives might require.
         */
        for (i = 0; i < timeout; ++i) {
                u32 edma_stat = readl(port_mmio + EDMA_STATUS);
                if ((edma_stat & empty_idle) == empty_idle)
                        break;
                udelay(per_loop);
        }
        /* ata_port_printk(ap, KERN_INFO, "%s: %u+ usecs\n", __func__, i); */
}

/**
 *      mv_stop_edma_engine - Disable eDMA engine
 *      @port_mmio: io base address
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static int mv_stop_edma_engine(void __iomem *port_mmio)
{
        int i;

        /* Disable eDMA.  The disable bit auto clears. */
        writelfl(EDMA_DS, port_mmio + EDMA_CMD);

        /* Wait for the chip to confirm eDMA is off. */
        for (i = 10000; i > 0; i--) {
                u32 reg = readl(port_mmio + EDMA_CMD);
                if (!(reg & EDMA_EN))
                        return 0;
                udelay(10);
        }
        return -EIO;
}

static int mv_stop_edma(struct ata_port *ap)
{
        void __iomem *port_mmio = mv_ap_base(ap);
        struct mv_port_priv *pp = ap->private_data;
        int err = 0;

        if (!(pp->pp_flags & MV_PP_FLAG_EDMA_EN))
                return 0;
        pp->pp_flags &= ~MV_PP_FLAG_EDMA_EN;
        mv_wait_for_edma_empty_idle(ap);
        if (mv_stop_edma_engine(port_mmio)) {
                ata_port_printk(ap, KERN_ERR, "Unable to stop eDMA\n");
                err = -EIO;
        }
        mv_edma_cfg(ap, 0, 0);
        return err;
}

#ifdef ATA_DEBUG
static void mv_dump_mem(void __iomem *start, unsigned bytes)
{
        int b, w;
        for (b = 0; b < bytes; ) {
                DPRINTK("%p: ", start + b);
                for (w = 0; b < bytes && w < 4; w++) {
                        printk("%08x ", readl(start + b));
                        b += sizeof(u32);
                }
                printk("\n");
        }
}
#endif

static void mv_dump_pci_cfg(struct pci_dev *pdev, unsigned bytes)
{
#ifdef ATA_DEBUG
        int b, w;
        u32 dw;
        for (b = 0; b < bytes; ) {
                DPRINTK("%02x: ", b);
                for (w = 0; b < bytes && w < 4; w++) {
                        (void) pci_read_config_dword(pdev, b, &dw);
                        printk("%08x ", dw);
                        b += sizeof(u32);
                }
                printk("\n");
        }
#endif
}
static void mv_dump_all_regs(void __iomem *mmio_base, int port,
                             struct pci_dev *pdev)
{
#ifdef ATA_DEBUG
        void __iomem *hc_base = mv_hc_base(mmio_base,
                                           port >> MV_PORT_HC_SHIFT);
        void __iomem *port_base;
        int start_port, num_ports, p, start_hc, num_hcs, hc;

        if (0 > port) {
                start_hc = start_port = 0;
                num_ports = 8;          /* shld be benign for 4 port devs */
                num_hcs = 2;
        } else {
                start_hc = port >> MV_PORT_HC_SHIFT;
                start_port = port;
                num_ports = num_hcs = 1;
        }
        DPRINTK("All registers for port(s) %u-%u:\n", start_port,
                num_ports > 1 ? num_ports - 1 : start_port);

        if (NULL != pdev) {
                DPRINTK("PCI config space regs:\n");
                mv_dump_pci_cfg(pdev, 0x68);
        }
        DPRINTK("PCI regs:\n");
        mv_dump_mem(mmio_base+0xc00, 0x3c);
        mv_dump_mem(mmio_base+0xd00, 0x34);
        mv_dump_mem(mmio_base+0xf00, 0x4);
        mv_dump_mem(mmio_base+0x1d00, 0x6c);
        for (hc = start_hc; hc < start_hc + num_hcs; hc++) {
                hc_base = mv_hc_base(mmio_base, hc);
                DPRINTK("HC regs (HC %i):\n", hc);
                mv_dump_mem(hc_base, 0x1c);
        }
        for (p = start_port; p < start_port + num_ports; p++) {
                port_base = mv_port_base(mmio_base, p);
                DPRINTK("EDMA regs (port %i):\n", p);
                mv_dump_mem(port_base, 0x54);
                DPRINTK("SATA regs (port %i):\n", p);
                mv_dump_mem(port_base+0x300, 0x60);
        }
#endif
}

static unsigned int mv_scr_offset(unsigned int sc_reg_in)
{
        unsigned int ofs;

        switch (sc_reg_in) {
        case SCR_STATUS:
        case SCR_CONTROL:
        case SCR_ERROR:
                ofs = SATA_STATUS + (sc_reg_in * sizeof(u32));
                break;
        case SCR_ACTIVE:
                ofs = SATA_ACTIVE;   /* active is not with the others */
                break;
        default:
                ofs = 0xffffffffU;
                break;
        }
        return ofs;
}

static int mv_scr_read(struct ata_link *link, unsigned int sc_reg_in, u32 *val)
{
        unsigned int ofs = mv_scr_offset(sc_reg_in);

        if (ofs != 0xffffffffU) {
                *val = readl(mv_ap_base(link->ap) + ofs);
                return 0;
        } else
                return -EINVAL;
}

static int mv_scr_write(struct ata_link *link, unsigned int sc_reg_in, u32 val)
{
        unsigned int ofs = mv_scr_offset(sc_reg_in);

        if (ofs != 0xffffffffU) {
                void __iomem *addr = mv_ap_base(link->ap) + ofs;
                if (sc_reg_in == SCR_CONTROL) {
                        /*
                         * Workaround for 88SX60x1 FEr SATA#26:
                         *
                         * COMRESETs have to take care not to accidently
                         * put the drive to sleep when writing SCR_CONTROL.
                         * Setting bits 12..15 prevents this problem.
                         *
                         * So if we see an outbound COMMRESET, set those bits.
                         * Ditto for the followup write that clears the reset.
                         *
                         * The proprietary driver does this for
                         * all chip versions, and so do we.
                         */
                        if ((val & 0xf) == 1 || (readl(addr) & 0xf) == 1)
                                val |= 0xf000;
                }
                writelfl(val, addr);
                return 0;
        } else
                return -EINVAL;
}

static void mv6_dev_config(struct ata_device *adev)
{
        /*
         * Deal with Gen-II ("mv6") hardware quirks/restrictions:
         *
         * Gen-II does not support NCQ over a port multiplier
         *  (no FIS-based switching).
         */
        if (adev->flags & ATA_DFLAG_NCQ) {
                if (sata_pmp_attached(adev->link->ap)) {
                        adev->flags &= ~ATA_DFLAG_NCQ;
                        ata_dev_printk(adev, KERN_INFO,
                                "NCQ disabled for command-based switching\n");
                }
        }
}

static int mv_qc_defer(struct ata_queued_cmd *qc)
{
        struct ata_link *link = qc->dev->link;
        struct ata_port *ap = link->ap;
        struct mv_port_priv *pp = ap->private_data;

        /*
         * Don't allow new commands if we're in a delayed EH state
         * for NCQ and/or FIS-based switching.
         */
        if (pp->pp_flags & MV_PP_FLAG_DELAYED_EH)
                return ATA_DEFER_PORT;
        /*
         * If the port is completely idle, then allow the new qc.
         */
        if (ap->nr_active_links == 0)
                return 0;

        /*
         * The port is operating in host queuing mode (EDMA) with NCQ
         * enabled, allow multiple NCQ commands.  EDMA also allows
         * queueing multiple DMA commands but libata core currently
         * doesn't allow it.
         */
        if ((pp->pp_flags & MV_PP_FLAG_EDMA_EN) &&
            (pp->pp_flags & MV_PP_FLAG_NCQ_EN) && ata_is_ncq(qc->tf.protocol))
                return 0;

        return ATA_DEFER_PORT;
}

static void mv_config_fbs(struct ata_port *ap, int want_ncq, int want_fbs)
{
        struct mv_port_priv *pp = ap->private_data;
        void __iomem *port_mmio;

        u32 fiscfg,   *old_fiscfg   = &pp->cached.fiscfg;
        u32 ltmode,   *old_ltmode   = &pp->cached.ltmode;
        u32 haltcond, *old_haltcond = &pp->cached.haltcond;

        ltmode   = *old_ltmode & ~LTMODE_BIT8;
        haltcond = *old_haltcond | EDMA_ERR_DEV;

        if (want_fbs) {
                fiscfg = *old_fiscfg | FISCFG_SINGLE_SYNC;
                ltmode = *old_ltmode | LTMODE_BIT8;
                if (want_ncq)
                        haltcond &= ~EDMA_ERR_DEV;
                else
                        fiscfg |=  FISCFG_WAIT_DEV_ERR;
        } else {
                fiscfg = *old_fiscfg & ~(FISCFG_SINGLE_SYNC | FISCFG_WAIT_DEV_ERR);
        }

        port_mmio = mv_ap_base(ap);
        mv_write_cached_reg(port_mmio + FISCFG, old_fiscfg, fiscfg);
        mv_write_cached_reg(port_mmio + LTMODE, old_ltmode, ltmode);
        mv_write_cached_reg(port_mmio + EDMA_HALTCOND, old_haltcond, haltcond);
}

static void mv_60x1_errata_sata25(struct ata_port *ap, int want_ncq)
{
        struct mv_host_priv *hpriv = ap->host->private_data;
        u32 old, new;

        /* workaround for 88SX60x1 FEr SATA#25 (part 1) */
        old = readl(hpriv->base + GPIO_PORT_CTL);
        if (want_ncq)
                new = old | (1 << 22);
        else
                new = old & ~(1 << 22);
        if (new != old)
                writel(new, hpriv->base + GPIO_PORT_CTL);
}

/**
 *      mv_bmdma_enable - set a magic bit on GEN_IIE to allow bmdma
 *      @ap: Port being initialized
 *
 *      There are two DMA modes on these chips:  basic DMA, and EDMA.
 *
 *      Bit-0 of the "EDMA RESERVED" register enables/disables use
 *      of basic DMA on the GEN_IIE versions of the chips.
 *
 *      This bit survives EDMA resets, and must be set for basic DMA
 *      to function, and should be cleared when EDMA is active.
 */
static void mv_bmdma_enable_iie(struct ata_port *ap, int enable_bmdma)
{
        struct mv_port_priv *pp = ap->private_data;
        u32 new, *old = &pp->cached.unknown_rsvd;

        if (enable_bmdma)
                new = *old | 1;
        else
                new = *old & ~1;
        mv_write_cached_reg(mv_ap_base(ap) + EDMA_UNKNOWN_RSVD, old, new);
}

/*
 * SOC chips have an issue whereby the HDD LEDs don't always blink
 * during I/O when NCQ is enabled. Enabling a special "LED blink" mode
 * of the SOC takes care of it, generating a steady blink rate when
 * any drive on the chip is active.
 *
 * Unfortunately, the blink mode is a global hardware setting for the SOC,
 * so we must use it whenever at least one port on the SOC has NCQ enabled.
 *
 * We turn "LED blink" off when NCQ is not in use anywhere, because the normal
 * LED operation works then, and provides better (more accurate) feedback.
 *
 * Note that this code assumes that an SOC never has more than one HC onboard.
 */
static void mv_soc_led_blink_enable(struct ata_port *ap)
{
        struct ata_host *host = ap->host;
        struct mv_host_priv *hpriv = host->private_data;
        void __iomem *hc_mmio;
        u32 led_ctrl;

        if (hpriv->hp_flags & MV_HP_QUIRK_LED_BLINK_EN)
                return;
        hpriv->hp_flags |= MV_HP_QUIRK_LED_BLINK_EN;
        hc_mmio = mv_hc_base_from_port(mv_host_base(host), ap->port_no);
        led_ctrl = readl(hc_mmio + SOC_LED_CTRL);
        writel(led_ctrl | SOC_LED_CTRL_BLINK, hc_mmio + SOC_LED_CTRL);
}

static void mv_soc_led_blink_disable(struct ata_port *ap)
{
        struct ata_host *host = ap->host;
        struct mv_host_priv *hpriv = host->private_data;
        void __iomem *hc_mmio;
        u32 led_ctrl;
        unsigned int port;

        if (!(hpriv->hp_flags & MV_HP_QUIRK_LED_BLINK_EN))
                return;

        /* disable led-blink only if no ports are using NCQ */
        for (port = 0; port < hpriv->n_ports; port++) {
                struct ata_port *this_ap = host->ports[port];
                struct mv_port_priv *pp = this_ap->private_data;

                if (pp->pp_flags & MV_PP_FLAG_NCQ_EN)
                        return;
        }

        hpriv->hp_flags &= ~MV_HP_QUIRK_LED_BLINK_EN;
        hc_mmio = mv_hc_base_from_port(mv_host_base(host), ap->port_no);
        led_ctrl = readl(hc_mmio + SOC_LED_CTRL);
        writel(led_ctrl & ~SOC_LED_CTRL_BLINK, hc_mmio + SOC_LED_CTRL);
}

static void mv_edma_cfg(struct ata_port *ap, int want_ncq, int want_edma)
{
        u32 cfg;
        struct mv_port_priv *pp    = ap->private_data;
        struct mv_host_priv *hpriv = ap->host->private_data;
        void __iomem *port_mmio    = mv_ap_base(ap);

        /* set up non-NCQ EDMA configuration */
        cfg = EDMA_CFG_Q_DEPTH;         /* always 0x1f for *all* chips */
        pp->pp_flags &=
          ~(MV_PP_FLAG_FBS_EN | MV_PP_FLAG_NCQ_EN | MV_PP_FLAG_FAKE_ATA_BUSY);

        if (IS_GEN_I(hpriv))
                cfg |= (1 << 8);        /* enab config burst size mask */

        else if (IS_GEN_II(hpriv)) {
                cfg |= EDMA_CFG_RD_BRST_EXT | EDMA_CFG_WR_BUFF_LEN;
                mv_60x1_errata_sata25(ap, want_ncq);

        } else if (IS_GEN_IIE(hpriv)) {
                int want_fbs = sata_pmp_attached(ap);
                /*
                 * Possible future enhancement:
                 *
                 * The chip can use FBS with non-NCQ, if we allow it,
                 * But first we need to have the error handling in place
                 * for this mode (datasheet section 7.3.15.4.2.3).
                 * So disallow non-NCQ FBS for now.
                 */
                want_fbs &= want_ncq;

                mv_config_fbs(ap, want_ncq, want_fbs);

                if (want_fbs) {
                        pp->pp_flags |= MV_PP_FLAG_FBS_EN;
                        cfg |= EDMA_CFG_EDMA_FBS; /* FIS-based switching */
                }

                cfg |= (1 << 23);       /* do not mask PM field in rx'd FIS */
                if (want_edma) {
                        cfg |= (1 << 22); /* enab 4-entry host queue cache */
                        if (!IS_SOC(hpriv))
                                cfg |= (1 << 18); /* enab early completion */
                }
                if (hpriv->hp_flags & MV_HP_CUT_THROUGH)
                        cfg |= (1 << 17); /* enab cut-thru (dis stor&forwrd) */
                mv_bmdma_enable_iie(ap, !want_edma);

                if (IS_SOC(hpriv)) {
                        if (want_ncq)
                                mv_soc_led_blink_enable(ap);
                        else
                                mv_soc_led_blink_disable(ap);
                }
        }

        if (want_ncq) {
                cfg |= EDMA_CFG_NCQ;
                pp->pp_flags |=  MV_PP_FLAG_NCQ_EN;
        }

        writelfl(cfg, port_mmio + EDMA_CFG);
}

static void mv_port_free_dma_mem(struct ata_port *ap)
{
        struct mv_host_priv *hpriv = ap->host->private_data;
        struct mv_port_priv *pp = ap->private_data;
        int tag;

        if (pp->crqb) {
                dma_pool_free(hpriv->crqb_pool, pp->crqb, pp->crqb_dma);
                pp->crqb = NULL;
        }
        if (pp->crpb) {
                dma_pool_free(hpriv->crpb_pool, pp->crpb, pp->crpb_dma);
                pp->crpb = NULL;
        }
        /*
         * For GEN_I, there's no NCQ, so we have only a single sg_tbl.
         * For later hardware, we have one unique sg_tbl per NCQ tag.
         */
        for (tag = 0; tag < MV_MAX_Q_DEPTH; ++tag) {
                if (pp->sg_tbl[tag]) {
                        if (tag == 0 || !IS_GEN_I(hpriv))
                                dma_pool_free(hpriv->sg_tbl_pool,
                                              pp->sg_tbl[tag],
                                              pp->sg_tbl_dma[tag]);
                        pp->sg_tbl[tag] = NULL;
                }
        }
}

/**
 *      mv_port_start - Port specific init/start routine.
 *      @ap: ATA channel to manipulate
 *
 *      Allocate and point to DMA memory, init port private memory,
 *      zero indices.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static int mv_port_start(struct ata_port *ap)
{
        struct device *dev = ap->host->dev;
        struct mv_host_priv *hpriv = ap->host->private_data;
        struct mv_port_priv *pp;
        unsigned long flags;
        int tag;

        pp = devm_kzalloc(dev, sizeof(*pp), GFP_KERNEL);
        if (!pp)
                return -ENOMEM;
        ap->private_data = pp;

        pp->crqb = dma_pool_alloc(hpriv->crqb_pool, GFP_KERNEL, &pp->crqb_dma);
        if (!pp->crqb)
                return -ENOMEM;
        memset(pp->crqb, 0, MV_CRQB_Q_SZ);

        pp->crpb = dma_pool_alloc(hpriv->crpb_pool, GFP_KERNEL, &pp->crpb_dma);
        if (!pp->crpb)
                goto out_port_free_dma_mem;
        memset(pp->crpb, 0, MV_CRPB_Q_SZ);

        /* 6041/6081 Rev. "C0" (and newer) are okay with async notify */
        if (hpriv->hp_flags & MV_HP_ERRATA_60X1C0)
                ap->flags |= ATA_FLAG_AN;
        /*
         * For GEN_I, there's no NCQ, so we only allocate a single sg_tbl.
         * For later hardware, we need one unique sg_tbl per NCQ tag.
         */
        for (tag = 0; tag < MV_MAX_Q_DEPTH; ++tag) {
                if (tag == 0 || !IS_GEN_I(hpriv)) {
                        pp->sg_tbl[tag] = dma_pool_alloc(hpriv->sg_tbl_pool,
                                              GFP_KERNEL, &pp->sg_tbl_dma[tag]);
                        if (!pp->sg_tbl[tag])
                                goto out_port_free_dma_mem;
                } else {
                        pp->sg_tbl[tag]     = pp->sg_tbl[0];
                        pp->sg_tbl_dma[tag] = pp->sg_tbl_dma[0];
                }
        }

        spin_lock_irqsave(ap->lock, flags);
        mv_save_cached_regs(ap);
        mv_edma_cfg(ap, 0, 0);
        spin_unlock_irqrestore(ap->lock, flags);

        return 0;

out_port_free_dma_mem:
        mv_port_free_dma_mem(ap);
        return -ENOMEM;
}

/**
 *      mv_port_stop - Port specific cleanup/stop routine.
 *      @ap: ATA channel to manipulate
 *
 *      Stop DMA, cleanup port memory.
 *
 *      LOCKING:
 *      This routine uses the host lock to protect the DMA stop.
 */
static void mv_port_stop(struct ata_port *ap)
{
        unsigned long flags;

        spin_lock_irqsave(ap->lock, flags);
        mv_stop_edma(ap);
        mv_enable_port_irqs(ap, 0);
        spin_unlock_irqrestore(ap->lock, flags);
        mv_port_free_dma_mem(ap);
}

/**
 *      mv_fill_sg - Fill out the Marvell ePRD (scatter gather) entries
 *      @qc: queued command whose SG list to source from
 *
 *      Populate the SG list and mark the last entry.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static void mv_fill_sg(struct ata_queued_cmd *qc)
{
        struct mv_port_priv *pp = qc->ap->private_data;
        struct scatterlist *sg;
        struct mv_sg *mv_sg, *last_sg = NULL;
        unsigned int si;

        mv_sg = pp->sg_tbl[qc->tag];
        for_each_sg(qc->sg, sg, qc->n_elem, si) {
                dma_addr_t addr = sg_dma_address(sg);
                u32 sg_len = sg_dma_len(sg);

                while (sg_len) {
                        u32 offset = addr & 0xffff;
                        u32 len = sg_len;

                        if (offset + len > 0x10000)
                                len = 0x10000 - offset;

                        mv_sg->addr = cpu_to_le32(addr & 0xffffffff);
                        mv_sg->addr_hi = cpu_to_le32((addr >> 16) >> 16);
                        mv_sg->flags_size = cpu_to_le32(len & 0xffff);
                        mv_sg->reserved = 0;

                        sg_len -= len;
                        addr += len;

                        last_sg = mv_sg;
                        mv_sg++;
                }
        }

        if (likely(last_sg))
                last_sg->flags_size |= cpu_to_le32(EPRD_FLAG_END_OF_TBL);
        mb(); /* ensure data structure is visible to the chipset */
}

static void mv_crqb_pack_cmd(__le16 *cmdw, u8 data, u8 addr, unsigned last)
{
        u16 tmp = data | (addr << CRQB_CMD_ADDR_SHIFT) | CRQB_CMD_CS |
                (last ? CRQB_CMD_LAST : 0);
        *cmdw = cpu_to_le16(tmp);
}

/**
 *      mv_sff_irq_clear - Clear hardware interrupt after DMA.
 *      @ap: Port associated with this ATA transaction.
 *
 *      We need this only for ATAPI bmdma transactions,
 *      as otherwise we experience spurious interrupts
 *      after libata-sff handles the bmdma interrupts.
 */
static void mv_sff_irq_clear(struct ata_port *ap)
{
        mv_clear_and_enable_port_irqs(ap, mv_ap_base(ap), ERR_IRQ);
}

/**
 *      mv_check_atapi_dma - Filter ATAPI cmds which are unsuitable for DMA.
 *      @qc: queued command to check for chipset/DMA compatibility.
 *
 *      The bmdma engines cannot handle speculative data sizes
 *      (bytecount under/over flow).  So only allow DMA for
 *      data transfer commands with known data sizes.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static int mv_check_atapi_dma(struct ata_queued_cmd *qc)
{
        struct scsi_cmnd *scmd = qc->scsicmd;

        if (scmd) {
                switch (scmd->cmnd[0]) {
                case READ_6:
                case READ_10:
                case READ_12:
                case WRITE_6:
                case WRITE_10:
                case WRITE_12:
                case GPCMD_READ_CD:
                case GPCMD_SEND_DVD_STRUCTURE:
                case GPCMD_SEND_CUE_SHEET:
                        return 0; /* DMA is safe */
                }
        }
        return -EOPNOTSUPP; /* use PIO instead */
}

/**
 *      mv_bmdma_setup - Set up BMDMA transaction
 *      @qc: queued command to prepare DMA for.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static void mv_bmdma_setup(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        void __iomem *port_mmio = mv_ap_base(ap);
        struct mv_port_priv *pp = ap->private_data;

        mv_fill_sg(qc);

        /* clear all DMA cmd bits */
        writel(0, port_mmio + BMDMA_CMD);

        /* load PRD table addr. */
        writel((pp->sg_tbl_dma[qc->tag] >> 16) >> 16,
                port_mmio + BMDMA_PRD_HIGH);
        writelfl(pp->sg_tbl_dma[qc->tag],
                port_mmio + BMDMA_PRD_LOW);

        /* issue r/w command */
        ap->ops->sff_exec_command(ap, &qc->tf);
}

/**
 *      mv_bmdma_start - Start a BMDMA transaction
 *      @qc: queued command to start DMA on.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static void mv_bmdma_start(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        void __iomem *port_mmio = mv_ap_base(ap);
        unsigned int rw = (qc->tf.flags & ATA_TFLAG_WRITE);
        u32 cmd = (rw ? 0 : ATA_DMA_WR) | ATA_DMA_START;

        /* start host DMA transaction */
        writelfl(cmd, port_mmio + BMDMA_CMD);
}

/**
 *      mv_bmdma_stop - Stop BMDMA transfer
 *      @qc: queued command to stop DMA on.
 *
 *      Clears the ATA_DMA_START flag in the bmdma control register
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static void mv_bmdma_stop(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        void __iomem *port_mmio = mv_ap_base(ap);
        u32 cmd;

        /* clear start/stop bit */
        cmd = readl(port_mmio + BMDMA_CMD);
        cmd &= ~ATA_DMA_START;
        writelfl(cmd, port_mmio + BMDMA_CMD);

        /* one-PIO-cycle guaranteed wait, per spec, for HDMA1:0 transition */
        ata_sff_dma_pause(ap);
}

/**
 *      mv_bmdma_status - Read BMDMA status
 *      @ap: port for which to retrieve DMA status.
 *
 *      Read and return equivalent of the sff BMDMA status register.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static u8 mv_bmdma_status(struct ata_port *ap)
{
        void __iomem *port_mmio = mv_ap_base(ap);
        u32 reg, status;

        /*
         * Other bits are valid only if ATA_DMA_ACTIVE==0,
         * and the ATA_DMA_INTR bit doesn't exist.
         */
        reg = readl(port_mmio + BMDMA_STATUS);
        if (reg & ATA_DMA_ACTIVE)
                status = ATA_DMA_ACTIVE;
        else
                status = (reg & ATA_DMA_ERR) | ATA_DMA_INTR;
        return status;
}

static void mv_rw_multi_errata_sata24(struct ata_queued_cmd *qc)
{
        struct ata_taskfile *tf = &qc->tf;
        /*
         * Workaround for 88SX60x1 FEr SATA#24.
         *
         * Chip may corrupt WRITEs if multi_count >= 4kB.
         * Note that READs are unaffected.
         *
         * It's not clear if this errata really means "4K bytes",
         * or if it always happens for multi_count > 7
         * regardless of device sector_size.
         *
         * So, for safety, any write with multi_count > 7
         * gets converted here into a regular PIO write instead:
         */
        if ((tf->flags & ATA_TFLAG_WRITE) && is_multi_taskfile(tf)) {
                if (qc->dev->multi_count > 7) {
                        switch (tf->command) {
                        case ATA_CMD_WRITE_MULTI:
                                tf->command = ATA_CMD_PIO_WRITE;
                                break;
                        case ATA_CMD_WRITE_MULTI_FUA_EXT:
                                tf->flags &= ~ATA_TFLAG_FUA; /* ugh */
                                /* fall through */
                        case ATA_CMD_WRITE_MULTI_EXT:
                                tf->command = ATA_CMD_PIO_WRITE_EXT;
                                break;
                        }
                }
        }
}

/**
 *      mv_qc_prep - Host specific command preparation.
 *      @qc: queued command to prepare
 *
 *      This routine simply redirects to the general purpose routine
 *      if command is not DMA.  Else, it handles prep of the CRQB
 *      (command request block), does some sanity checking, and calls
 *      the SG load routine.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static void mv_qc_prep(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct mv_port_priv *pp = ap->private_data;
        __le16 *cw;
        struct ata_taskfile *tf = &qc->tf;
        u16 flags = 0;
        unsigned in_index;

        switch (tf->protocol) {
        case ATA_PROT_DMA:
        case ATA_PROT_NCQ:
                break;  /* continue below */
        case ATA_PROT_PIO:
                mv_rw_multi_errata_sata24(qc);
                return;
        default:
                return;
        }

        /* Fill in command request block
         */
        if (!(tf->flags & ATA_TFLAG_WRITE))
                flags |= CRQB_FLAG_READ;
        WARN_ON(MV_MAX_Q_DEPTH <= qc->tag);
        flags |= qc->tag << CRQB_TAG_SHIFT;
        flags |= (qc->dev->link->pmp & 0xf) << CRQB_PMP_SHIFT;

        /* get current queue index from software */
        in_index = pp->req_idx;

        pp->crqb[in_index].sg_addr =
                cpu_to_le32(pp->sg_tbl_dma[qc->tag] & 0xffffffff);
        pp->crqb[in_index].sg_addr_hi =
                cpu_to_le32((pp->sg_tbl_dma[qc->tag] >> 16) >> 16);
        pp->crqb[in_index].ctrl_flags = cpu_to_le16(flags);

        cw = &pp->crqb[in_index].ata_cmd[0];

        /* Sadly, the CRQB cannot accomodate all registers--there are
         * only 11 bytes...so we must pick and choose required
         * registers based on the command.  So, we drop feature and
         * hob_feature for [RW] DMA commands, but they are needed for
         * NCQ.  NCQ will drop hob_nsect, which is not needed there
         * (nsect is used only for the tag; feat/hob_feat hold true nsect).
         */
        switch (tf->command) {
        case ATA_CMD_READ:
        case ATA_CMD_READ_EXT:
        case ATA_CMD_WRITE:
        case ATA_CMD_WRITE_EXT:
        case ATA_CMD_WRITE_FUA_EXT:
                mv_crqb_pack_cmd(cw++, tf->hob_nsect, ATA_REG_NSECT, 0);
                break;
        case ATA_CMD_FPDMA_READ:
        case ATA_CMD_FPDMA_WRITE:
                mv_crqb_pack_cmd(cw++, tf->hob_feature, ATA_REG_FEATURE, 0);
                mv_crqb_pack_cmd(cw++, tf->feature, ATA_REG_FEATURE, 0);

                break;
        default:
                /* The only other commands EDMA supports in non-queued and
                 * non-NCQ mode are: [RW] STREAM DMA and W DMA FUA EXT, none
                 * of which are defined/used by Linux.  If we get here, this
                 * driver needs work.
                 *
                 * FIXME: modify libata to give qc_prep a return value and
                 * return error here.
                 */
                BUG_ON(tf->command);
                break;
        }
        mv_crqb_pack_cmd(cw++, tf->nsect, ATA_REG_NSECT, 0);
        mv_crqb_pack_cmd(cw++, tf->hob_lbal, ATA_REG_LBAL, 0);
        mv_crqb_pack_cmd(cw++, tf->lbal, ATA_REG_LBAL, 0);
        mv_crqb_pack_cmd(cw++, tf->hob_lbam, ATA_REG_LBAM, 0);
        mv_crqb_pack_cmd(cw++, tf->lbam, ATA_REG_LBAM, 0);
        mv_crqb_pack_cmd(cw++, tf->hob_lbah, ATA_REG_LBAH, 0);
        mv_crqb_pack_cmd(cw++, tf->lbah, ATA_REG_LBAH, 0);
        mv_crqb_pack_cmd(cw++, tf->device, ATA_REG_DEVICE, 0);
        mv_crqb_pack_cmd(cw++, tf->command, ATA_REG_CMD, 1);    /* last */

        if (!(qc->flags & ATA_QCFLAG_DMAMAP))
                return;
        mv_fill_sg(qc);
}

/**
 *      mv_qc_prep_iie - Host specific command preparation.
 *      @qc: queued command to prepare
 *
 *      This routine simply redirects to the general purpose routine
 *      if command is not DMA.  Else, it handles prep of the CRQB
 *      (command request block), does some sanity checking, and calls
 *      the SG load routine.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static void mv_qc_prep_iie(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct mv_port_priv *pp = ap->private_data;
        struct mv_crqb_iie *crqb;
        struct ata_taskfile *tf = &qc->tf;
        unsigned in_index;
        u32 flags = 0;

        if ((tf->protocol != ATA_PROT_DMA) &&
            (tf->protocol != ATA_PROT_NCQ))
                return;

        /* Fill in Gen IIE command request block */
        if (!(tf->flags & ATA_TFLAG_WRITE))
                flags |= CRQB_FLAG_READ;

        WARN_ON(MV_MAX_Q_DEPTH <= qc->tag);
        flags |= qc->tag << CRQB_TAG_SHIFT;
        flags |= qc->tag << CRQB_HOSTQ_SHIFT;
        flags |= (qc->dev->link->pmp & 0xf) << CRQB_PMP_SHIFT;

        /* get current queue index from software */
        in_index = pp->req_idx;

        crqb = (struct mv_crqb_iie *) &pp->crqb[in_index];
        crqb->addr = cpu_to_le32(pp->sg_tbl_dma[qc->tag] & 0xffffffff);
        crqb->addr_hi = cpu_to_le32((pp->sg_tbl_dma[qc->tag] >> 16) >> 16);
        crqb->flags = cpu_to_le32(flags);

        crqb->ata_cmd[0] = cpu_to_le32(
                        (tf->command << 16) |
                        (tf->feature << 24)
                );
        crqb->ata_cmd[1] = cpu_to_le32(
                        (tf->lbal << 0) |
                        (tf->lbam << 8) |
                        (tf->lbah << 16) |
                        (tf->device << 24)
                );
        crqb->ata_cmd[2] = cpu_to_le32(
                        (tf->hob_lbal << 0) |
                        (tf->hob_lbam << 8) |
                        (tf->hob_lbah << 16) |
                        (tf->hob_feature << 24)
                );
        crqb->ata_cmd[3] = cpu_to_le32(
                        (tf->nsect << 0) |
                        (tf->hob_nsect << 8)
                );

        if (!(qc->flags & ATA_QCFLAG_DMAMAP))
                return;
        mv_fill_sg(qc);
}

/**
 *      mv_sff_check_status - fetch device status, if valid
 *      @ap: ATA port to fetch status from
 *
 *      When using command issue via mv_qc_issue_fis(),
 *      the initial ATA_BUSY state does not show up in the
 *      ATA status (shadow) register.  This can confuse libata!
 *
 *      So we have a hook here to fake ATA_BUSY for that situation,
 *      until the first time a BUSY, DRQ, or ERR bit is seen.
 *
 *      The rest of the time, it simply returns the ATA status register.
 */
static u8 mv_sff_check_status(struct ata_port *ap)
{
        u8 stat = ioread8(ap->ioaddr.status_addr);
        struct mv_port_priv *pp = ap->private_data;

        if (pp->pp_flags & MV_PP_FLAG_FAKE_ATA_BUSY) {
                if (stat & (ATA_BUSY | ATA_DRQ | ATA_ERR))
                        pp->pp_flags &= ~MV_PP_FLAG_FAKE_ATA_BUSY;
                else
                        stat = ATA_BUSY;
        }
        return stat;
}

/**
 *      mv_send_fis - Send a FIS, using the "Vendor-Unique FIS" register
 *      @fis: fis to be sent
 *      @nwords: number of 32-bit words in the fis
 */
static unsigned int mv_send_fis(struct ata_port *ap, u32 *fis, int nwords)
{
        void __iomem *port_mmio = mv_ap_base(ap);
        u32 ifctl, old_ifctl, ifstat;
        int i, timeout = 200, final_word = nwords - 1;

        /* Initiate FIS transmission mode */
        old_ifctl = readl(port_mmio + SATA_IFCTL);
        ifctl = 0x100 | (old_ifctl & 0xf);
        writelfl(ifctl, port_mmio + SATA_IFCTL);

        /* Send all words of the FIS except for the final word */
        for (i = 0; i < final_word; ++i)
                writel(fis[i], port_mmio + VENDOR_UNIQUE_FIS);

        /* Flag end-of-transmission, and then send the final word */
        writelfl(ifctl | 0x200, port_mmio + SATA_IFCTL);
        writelfl(fis[final_word], port_mmio + VENDOR_UNIQUE_FIS);

        /*
         * Wait for FIS transmission to complete.
         * This typically takes just a single iteration.
         */
        do {
                ifstat = readl(port_mmio + SATA_IFSTAT);
        } while (!(ifstat & 0x1000) && --timeout);

        /* Restore original port configuration */
        writelfl(old_ifctl, port_mmio + SATA_IFCTL);

        /* See if it worked */
        if ((ifstat & 0x3000) != 0x1000) {
                ata_port_printk(ap, KERN_WARNING,
                                "%s transmission error, ifstat=%08x\n",
                                __func__, ifstat);
                return AC_ERR_OTHER;
        }
        return 0;
}

/**
 *      mv_qc_issue_fis - Issue a command directly as a FIS
 *      @qc: queued command to start
 *
 *      Note that the ATA shadow registers are not updated
 *      after command issue, so the device will appear "READY"
 *      if polled, even while it is BUSY processing the command.
 *
 *      So we use a status hook to fake ATA_BUSY until the drive changes state.
 *
 *      Note: we don't get updated shadow regs on *completion*
 *      of non-data commands. So avoid sending them via this function,
 *      as they will appear to have completed immediately.
 *
 *      GEN_IIE has special registers that we could get the result tf from,
 *      but earlier chipsets do not.  For now, we ignore those registers.
 */
static unsigned int mv_qc_issue_fis(struct ata_queued_cmd *qc)
{
        struct ata_port *ap = qc->ap;
        struct mv_port_priv *pp = ap->private_data;
        struct ata_link *link = qc->dev->link;
        u32 fis[5];
        int err = 0;

        ata_tf_to_fis(&qc->tf, link->pmp, 1, (void *)fis);
        err = mv_send_fis(ap, fis, sizeof(fis) / sizeof(fis[0]));
        if (err)
                return err;

        switch (qc->tf.protocol) {
        case ATAPI_PROT_PIO:
                pp->pp_flags |= MV_PP_FLAG_FAKE_ATA_BUSY;
                /* fall through */
        case ATAPI_PROT_NODATA:
                ap->hsm_task_state = HSM_ST_FIRST;
                break;
        case ATA_PROT_PIO:
                pp->pp_flags |= MV_PP_FLAG_FAKE_ATA_BUSY;
                if (qc->tf.flags & ATA_TFLAG_WRITE)
                        ap->hsm_task_state = HSM_ST_FIRST;
                else
                        ap->hsm_task_state = HSM_ST;
                break;
        default:
                ap->hsm_task_state = HSM_ST_LAST;
                break;
        }

        if (qc->tf.flags & ATA_TFLAG_POLLING)
                ata_pio_queue_task(ap, qc, 0);
        return 0;
}

/**
 *      mv_qc_issue - Initiate a command to the host
 *      @qc: queued command to start
 *
 *      This routine simply redirects to the general purpose routine
 *      if command is not DMA.  Else, it sanity checks our local
 *      caches of the request producer/consumer indices then enables
 *      DMA and bumps the request producer index.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static unsigned int mv_qc_issue(struct ata_queued_cmd *qc)
{
        static int limit_warnings = 10;
        struct ata_port *ap = qc->ap;
        void __iomem *port_mmio = mv_ap_base(ap);
        struct mv_port_priv *pp = ap->private_data;
        u32 in_index;
        unsigned int port_irqs;

        pp->pp_flags &= ~MV_PP_FLAG_FAKE_ATA_BUSY; /* paranoia */

        switch (qc->tf.protocol) {
        case ATA_PROT_DMA:
        case ATA_PROT_NCQ:
                mv_start_edma(ap, port_mmio, pp, qc->tf.protocol);
                pp->req_idx = (pp->req_idx + 1) & MV_MAX_Q_DEPTH_MASK;
                in_index = pp->req_idx << EDMA_REQ_Q_PTR_SHIFT;

                /* Write the request in pointer to kick the EDMA to life */
                writelfl((pp->crqb_dma & EDMA_REQ_Q_BASE_LO_MASK) | in_index,
                                        port_mmio + EDMA_REQ_Q_IN_PTR);
                return 0;

        case ATA_PROT_PIO:
                /*
                 * Errata SATA#16, SATA#24: warn if multiple DRQs expected.
                 *
                 * Someday, we might implement special polling workarounds
                 * for these, but it all seems rather unnecessary since we
                 * normally use only DMA for commands which transfer more
                 * than a single block of data.
                 *
                 * Much of the time, this could just work regardless.
                 * So for now, just log the incident, and allow the attempt.
                 */
                if (limit_warnings > 0 && (qc->nbytes / qc->sect_size) > 1) {
                        --limit_warnings;
                        ata_link_printk(qc->dev->link, KERN_WARNING, DRV_NAME
                                        ": attempting PIO w/multiple DRQ: "
                                        "this may fail due to h/w errata\n");
                }
                /* drop through */
        case ATA_PROT_NODATA:
        case ATAPI_PROT_PIO:
        case ATAPI_PROT_NODATA:
                if (ap->flags & ATA_FLAG_PIO_POLLING)
                        qc->tf.flags |= ATA_TFLAG_POLLING;
                break;
        }

        if (qc->tf.flags & ATA_TFLAG_POLLING)
                port_irqs = ERR_IRQ;    /* mask device interrupt when polling */
        else
                port_irqs = ERR_IRQ | DONE_IRQ; /* unmask all interrupts */

        /*
         * We're about to send a non-EDMA capable command to the
         * port.  Turn off EDMA so there won't be problems accessing
         * shadow block, etc registers.
         */
        mv_stop_edma(ap);
        mv_clear_and_enable_port_irqs(ap, mv_ap_base(ap), port_irqs);
        mv_pmp_select(ap, qc->dev->link->pmp);

        if (qc->tf.command == ATA_CMD_READ_LOG_EXT) {
                struct mv_host_priv *hpriv = ap->host->private_data;
                /*
                 * Workaround for 88SX60x1 FEr SATA#25 (part 2).
                 *
                 * After any NCQ error, the READ_LOG_EXT command
                 * from libata-eh *must* use mv_qc_issue_fis().
                 * Otherwise it might fail, due to chip errata.
                 *
                 * Rather than special-case it, we'll just *always*
                 * use this method here for READ_LOG_EXT, making for
                 * easier testing.
                 */
                if (IS_GEN_II(hpriv))
                        return mv_qc_issue_fis(qc);
        }
        return ata_sff_qc_issue(qc);
}

static struct ata_queued_cmd *mv_get_active_qc(struct ata_port *ap)
{
        struct mv_port_priv *pp = ap->private_data;
        struct ata_queued_cmd *qc;

        if (pp->pp_flags & MV_PP_FLAG_NCQ_EN)
                return NULL;
        qc = ata_qc_from_tag(ap, ap->link.active_tag);
        if (qc) {
                if (qc->tf.flags & ATA_TFLAG_POLLING)
                        qc = NULL;
                else if (!(qc->flags & ATA_QCFLAG_ACTIVE))
                        qc = NULL;
        }
        return qc;
}

static void mv_pmp_error_handler(struct ata_port *ap)
{
        unsigned int pmp, pmp_map;
        struct mv_port_priv *pp = ap->private_data;

        if (pp->pp_flags & MV_PP_FLAG_DELAYED_EH) {
                /*
                 * Perform NCQ error analysis on failed PMPs
                 * before we freeze the port entirely.
                 *
                 * The failed PMPs are marked earlier by mv_pmp_eh_prep().
                 */
                pmp_map = pp->delayed_eh_pmp_map;
                pp->pp_flags &= ~MV_PP_FLAG_DELAYED_EH;
                for (pmp = 0; pmp_map != 0; pmp++) {
                        unsigned int this_pmp = (1 << pmp);
                        if (pmp_map & this_pmp) {
                                struct ata_link *link = &ap->pmp_link[pmp];
                                pmp_map &= ~this_pmp;
                                ata_eh_analyze_ncq_error(link);
                        }
                }
                ata_port_freeze(ap);
        }
        sata_pmp_error_handler(ap);
}

static unsigned int mv_get_err_pmp_map(struct ata_port *ap)
{
        void __iomem *port_mmio = mv_ap_base(ap);

        return readl(port_mmio + SATA_TESTCTL) >> 16;
}

static void mv_pmp_eh_prep(struct ata_port *ap, unsigned int pmp_map)
{
        struct ata_eh_info *ehi;
        unsigned int pmp;

        /*
         * Initialize EH info for PMPs which saw device errors
         */
        ehi = &ap->link.eh_info;
        for (pmp = 0; pmp_map != 0; pmp++) {
                unsigned int this_pmp = (1 << pmp);
                if (pmp_map & this_pmp) {
                        struct ata_link *link = &ap->pmp_link[pmp];

                        pmp_map &= ~this_pmp;
                        ehi = &link->eh_info;
                        ata_ehi_clear_desc(ehi);
                        ata_ehi_push_desc(ehi, "dev err");
                        ehi->err_mask |= AC_ERR_DEV;
                        ehi->action |= ATA_EH_RESET;
                        ata_link_abort(link);
                }
        }
}

static int mv_req_q_empty(struct ata_port *ap)
{
        void __iomem *port_mmio = mv_ap_base(ap);
        u32 in_ptr, out_ptr;

        in_ptr  = (readl(port_mmio + EDMA_REQ_Q_IN_PTR)
                        >> EDMA_REQ_Q_PTR_SHIFT) & MV_MAX_Q_DEPTH_MASK;
        out_ptr = (readl(port_mmio + EDMA_REQ_Q_OUT_PTR)
                        >> EDMA_REQ_Q_PTR_SHIFT) & MV_MAX_Q_DEPTH_MASK;
        return (in_ptr == out_ptr);     /* 1 == queue_is_empty */
}

static int mv_handle_fbs_ncq_dev_err(struct ata_port *ap)
{
        struct mv_port_priv *pp = ap->private_data;
        int failed_links;
        unsigned int old_map, new_map;

        /*
         * Device error during FBS+NCQ operation:
         *
         * Set a port flag to prevent further I/O being enqueued.
         * Leave the EDMA running to drain outstanding commands from this port.
         * Perform the post-mortem/EH only when all responses are complete.
         * Follow recovery sequence from 6042/7042 datasheet (7.3.15.4.2.2).
         */
        if (!(pp->pp_flags & MV_PP_FLAG_DELAYED_EH)) {
                pp->pp_flags |= MV_PP_FLAG_DELAYED_EH;
                pp->delayed_eh_pmp_map = 0;
        }
        old_map = pp->delayed_eh_pmp_map;
        new_map = old_map | mv_get_err_pmp_map(ap);

        if (old_map != new_map) {
                pp->delayed_eh_pmp_map = new_map;
                mv_pmp_eh_prep(ap, new_map & ~old_map);
        }
        failed_links = hweight16(new_map);

        ata_port_printk(ap, KERN_INFO, "%s: pmp_map=%04x qc_map=%04x "
                        "failed_links=%d nr_active_links=%d\n",
                        __func__, pp->delayed_eh_pmp_map,
                        ap->qc_active, failed_links,
                        ap->nr_active_links);

        if (ap->nr_active_links <= failed_links && mv_req_q_empty(ap)) {
                mv_process_crpb_entries(ap, pp);
                mv_stop_edma(ap);
                mv_eh_freeze(ap);
                ata_port_printk(ap, KERN_INFO, "%s: done\n", __func__);
                return 1;       /* handled */
        }
        ata_port_printk(ap, KERN_INFO, "%s: waiting\n", __func__);
        return 1;       /* handled */
}

static int mv_handle_fbs_non_ncq_dev_err(struct ata_port *ap)
{
        /*
         * Possible future enhancement:
         *
         * FBS+non-NCQ operation is not yet implemented.
         * See related notes in mv_edma_cfg().
         *
         * Device error during FBS+non-NCQ operation:
         *
         * We need to snapshot the shadow registers for each failed command.
         * Follow recovery sequence from 6042/7042 datasheet (7.3.15.4.2.3).
         */
        return 0;       /* not handled */
}

static int mv_handle_dev_err(struct ata_port *ap, u32 edma_err_cause)
{
        struct mv_port_priv *pp = ap->private_data;

        if (!(pp->pp_flags & MV_PP_FLAG_EDMA_EN))
                return 0;       /* EDMA was not active: not handled */
        if (!(pp->pp_flags & MV_PP_FLAG_FBS_EN))
                return 0;       /* FBS was not active: not handled */

        if (!(edma_err_cause & EDMA_ERR_DEV))
                return 0;       /* non DEV error: not handled */
        edma_err_cause &= ~EDMA_ERR_IRQ_TRANSIENT;
        if (edma_err_cause & ~(EDMA_ERR_DEV | EDMA_ERR_SELF_DIS))
                return 0;       /* other problems: not handled */

        if (pp->pp_flags & MV_PP_FLAG_NCQ_EN) {
                /*
                 * EDMA should NOT have self-disabled for this case.
                 * If it did, then something is wrong elsewhere,
                 * and we cannot handle it here.
                 */
                if (edma_err_cause & EDMA_ERR_SELF_DIS) {
                        ata_port_printk(ap, KERN_WARNING,
                                "%s: err_cause=0x%x pp_flags=0x%x\n",
                                __func__, edma_err_cause, pp->pp_flags);
                        return 0; /* not handled */
                }
                return mv_handle_fbs_ncq_dev_err(ap);
        } else {
                /*
                 * EDMA should have self-disabled for this case.
                 * If it did not, then something is wrong elsewhere,
                 * and we cannot handle it here.
                 */
                if (!(edma_err_cause & EDMA_ERR_SELF_DIS)) {
                        ata_port_printk(ap, KERN_WARNING,
                                "%s: err_cause=0x%x pp_flags=0x%x\n",
                                __func__, edma_err_cause, pp->pp_flags);
                        return 0; /* not handled */
                }
                return mv_handle_fbs_non_ncq_dev_err(ap);
        }
        return 0;       /* not handled */
}

static void mv_unexpected_intr(struct ata_port *ap, int edma_was_enabled)
{
        struct ata_eh_info *ehi = &ap->link.eh_info;
        char *when = "idle";

        ata_ehi_clear_desc(ehi);
        if (ap->flags & ATA_FLAG_DISABLED) {
                when = "disabled";
        } else if (edma_was_enabled) {
                when = "EDMA enabled";
        } else {
                struct ata_queued_cmd *qc = ata_qc_from_tag(ap, ap->link.active_tag);
                if (qc && (qc->tf.flags & ATA_TFLAG_POLLING))
                        when = "polling";
        }
        ata_ehi_push_desc(ehi, "unexpected device interrupt while %s", when);
        ehi->err_mask |= AC_ERR_OTHER;
        ehi->action   |= ATA_EH_RESET;
        ata_port_freeze(ap);
}

/**
 *      mv_err_intr - Handle error interrupts on the port
 *      @ap: ATA channel to manipulate
 *
 *      Most cases require a full reset of the chip's state machine,
 *      which also performs a COMRESET.
 *      Also, if the port disabled DMA, update our cached copy to match.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static void mv_err_intr(struct ata_port *ap)
{
        void __iomem *port_mmio = mv_ap_base(ap);
        u32 edma_err_cause, eh_freeze_mask, serr = 0;
        u32 fis_cause = 0;
        struct mv_port_priv *pp = ap->private_data;
        struct mv_host_priv *hpriv = ap->host->private_data;
        unsigned int action = 0, err_mask = 0;
        struct ata_eh_info *ehi = &ap->link.eh_info;
        struct ata_queued_cmd *qc;
        int abort = 0;

        /*
         * Read and clear the SError and err_cause bits.
         * For GenIIe, if EDMA_ERR_TRANS_IRQ_7 is set, we also must read/clear
         * the FIS_IRQ_CAUSE register before clearing edma_err_cause.
         */
        sata_scr_read(&ap->link, SCR_ERROR, &serr);
        sata_scr_write_flush(&ap->link, SCR_ERROR, serr);

        edma_err_cause = readl(port_mmio + EDMA_ERR_IRQ_CAUSE);
        if (IS_GEN_IIE(hpriv) && (edma_err_cause & EDMA_ERR_TRANS_IRQ_7)) {
                fis_cause = readl(port_mmio + FIS_IRQ_CAUSE);
                writelfl(~fis_cause, port_mmio + FIS_IRQ_CAUSE);
        }
        writelfl(~edma_err_cause, port_mmio + EDMA_ERR_IRQ_CAUSE);

        if (edma_err_cause & EDMA_ERR_DEV) {
                /*
                 * Device errors during FIS-based switching operation
                 * require special handling.
                 */
                if (mv_handle_dev_err(ap, edma_err_cause))
                        return;
        }

        qc = mv_get_active_qc(ap);
        ata_ehi_clear_desc(ehi);
        ata_ehi_push_desc(ehi, "edma_err_cause=%08x pp_flags=%08x",
                          edma_err_cause, pp->pp_flags);

        if (IS_GEN_IIE(hpriv) && (edma_err_cause & EDMA_ERR_TRANS_IRQ_7)) {
                ata_ehi_push_desc(ehi, "fis_cause=%08x", fis_cause);
                if (fis_cause & FIS_IRQ_CAUSE_AN) {
                        u32 ec = edma_err_cause &
                               ~(EDMA_ERR_TRANS_IRQ_7 | EDMA_ERR_IRQ_TRANSIENT);
                        sata_async_notification(ap);
                        if (!ec)
                                return; /* Just an AN; no need for the nukes */
                        ata_ehi_push_desc(ehi, "SDB notify");
                }
        }
        /*
         * All generations share these EDMA error cause bits:
         */
        if (edma_err_cause & EDMA_ERR_DEV) {
                err_mask |= AC_ERR_DEV;
                action |= ATA_EH_RESET;
                ata_ehi_push_desc(ehi, "dev error");
        }
        if (edma_err_cause & (EDMA_ERR_D_PAR | EDMA_ERR_PRD_PAR |
                        EDMA_ERR_CRQB_PAR | EDMA_ERR_CRPB_PAR |
                        EDMA_ERR_INTRL_PAR)) {
                err_mask |= AC_ERR_ATA_BUS;
                action |= ATA_EH_RESET;
                ata_ehi_push_desc(ehi, "parity error");
        }
        if (edma_err_cause & (EDMA_ERR_DEV_DCON | EDMA_ERR_DEV_CON)) {
                ata_ehi_hotplugged(ehi);
                ata_ehi_push_desc(ehi, edma_err_cause & EDMA_ERR_DEV_DCON ?
                        "dev disconnect" : "dev connect");
                action |= ATA_EH_RESET;
        }

        /*
         * Gen-I has a different SELF_DIS bit,
         * different FREEZE bits, and no SERR bit:
         */
        if (IS_GEN_I(hpriv)) {
                eh_freeze_mask = EDMA_EH_FREEZE_5;
                if (edma_err_cause & EDMA_ERR_SELF_DIS_5) {
                        pp->pp_flags &= ~MV_PP_FLAG_EDMA_EN;
                        ata_ehi_push_desc(ehi, "EDMA self-disable");
                }
        } else {
                eh_freeze_mask = EDMA_EH_FREEZE;
                if (edma_err_cause & EDMA_ERR_SELF_DIS) {
                        pp->pp_flags &= ~MV_PP_FLAG_EDMA_EN;
                        ata_ehi_push_desc(ehi, "EDMA self-disable");
                }
                if (edma_err_cause & EDMA_ERR_SERR) {
                        ata_ehi_push_desc(ehi, "SError=%08x", serr);
                        err_mask |= AC_ERR_ATA_BUS;
                        action |= ATA_EH_RESET;
                }
        }

        if (!err_mask) {
                err_mask = AC_ERR_OTHER;
                action |= ATA_EH_RESET;
        }

        ehi->serror |= serr;
        ehi->action |= action;

        if (qc)
                qc->err_mask |= err_mask;
        else
                ehi->err_mask |= err_mask;

        if (err_mask == AC_ERR_DEV) {
                /*
                 * Cannot do ata_port_freeze() here,
                 * because it would kill PIO access,
                 * which is needed for further diagnosis.
                 */
                mv_eh_freeze(ap);
                abort = 1;
        } else if (edma_err_cause & eh_freeze_mask) {
                /*
                 * Note to self: ata_port_freeze() calls ata_port_abort()
                 */
                ata_port_freeze(ap);
        } else {
                abort = 1;
        }

        if (abort) {
                if (qc)
                        ata_link_abort(qc->dev->link);
                else
                        ata_port_abort(ap);
        }
}

static void mv_process_crpb_response(struct ata_port *ap,
                struct mv_crpb *response, unsigned int tag, int ncq_enabled)
{
        struct ata_queued_cmd *qc = ata_qc_from_tag(ap, tag);

        if (qc) {
                u8 ata_status;
                u16 edma_status = le16_to_cpu(response->flags);
                /*
                 * edma_status from a response queue entry:
                 *   LSB is from EDMA_ERR_IRQ_CAUSE (non-NCQ only).
                 *   MSB is saved ATA status from command completion.
                 */
                if (!ncq_enabled) {
                        u8 err_cause = edma_status & 0xff & ~EDMA_ERR_DEV;
                        if (err_cause) {
                                /*
                                 * Error will be seen/handled by mv_err_intr().
                                 * So do nothing at all here.
                                 */
                                return;
                        }
                }
                ata_status = edma_status >> CRPB_FLAG_STATUS_SHIFT;
                if (!ac_err_mask(ata_status))
                        ata_qc_complete(qc);
                /* else: leave it for mv_err_intr() */
        } else {
                ata_port_printk(ap, KERN_ERR, "%s: no qc for tag=%d\n",
                                __func__, tag);
        }
}

static void mv_process_crpb_entries(struct ata_port *ap, struct mv_port_priv *pp)
{
        void __iomem *port_mmio = mv_ap_base(ap);
        struct mv_host_priv *hpriv = ap->host->private_data;
        u32 in_index;
        bool work_done = false;
        int ncq_enabled = (pp->pp_flags & MV_PP_FLAG_NCQ_EN);

        /* Get the hardware queue position index */
        in_index = (readl(port_mmio + EDMA_RSP_Q_IN_PTR)
                        >> EDMA_RSP_Q_PTR_SHIFT) & MV_MAX_Q_DEPTH_MASK;

        /* Process new responses from since the last time we looked */
        while (in_index != pp->resp_idx) {
                unsigned int tag;
                struct mv_crpb *response = &pp->crpb[pp->resp_idx];

                pp->resp_idx = (pp->resp_idx + 1) & MV_MAX_Q_DEPTH_MASK;

                if (IS_GEN_I(hpriv)) {
                        /* 50xx: no NCQ, only one command active at a time */
                        tag = ap->link.active_tag;
                } else {
                        /* Gen II/IIE: get command tag from CRPB entry */
                        tag = le16_to_cpu(response->id) & 0x1f;
                }
                mv_process_crpb_response(ap, response, tag, ncq_enabled);
                work_done = true;
        }

        /* Update the software queue position index in hardware */
        if (work_done)
                writelfl((pp->crpb_dma & EDMA_RSP_Q_BASE_LO_MASK) |
                         (pp->resp_idx << EDMA_RSP_Q_PTR_SHIFT),
                         port_mmio + EDMA_RSP_Q_OUT_PTR);
}

static void mv_port_intr(struct ata_port *ap, u32 port_cause)
{
        struct mv_port_priv *pp;
        int edma_was_enabled;

        if (!ap || (ap->flags & ATA_FLAG_DISABLED)) {
                mv_unexpected_intr(ap, 0);
                return;
        }
        /*
         * Grab a snapshot of the EDMA_EN flag setting,
         * so that we have a consistent view for this port,
         * even if something we call of our routines changes it.
         */
        pp = ap->private_data;
        edma_was_enabled = (pp->pp_flags & MV_PP_FLAG_EDMA_EN);
        /*
         * Process completed CRPB response(s) before other events.
         */
        if (edma_was_enabled && (port_cause & DONE_IRQ)) {
                mv_process_crpb_entries(ap, pp);
                if (pp->pp_flags & MV_PP_FLAG_DELAYED_EH)
                        mv_handle_fbs_ncq_dev_err(ap);
        }
        /*
         * Handle chip-reported errors, or continue on to handle PIO.
         */
        if (unlikely(port_cause & ERR_IRQ)) {
                mv_err_intr(ap);
        } else if (!edma_was_enabled) {
                struct ata_queued_cmd *qc = mv_get_active_qc(ap);
                if (qc)
                        ata_sff_host_intr(ap, qc);
                else
                        mv_unexpected_intr(ap, edma_was_enabled);
        }
}

/**
 *      mv_host_intr - Handle all interrupts on the given host controller
 *      @host: host specific structure
 *      @main_irq_cause: Main interrupt cause register for the chip.
 *
 *      LOCKING:
 *      Inherited from caller.
 */
static int mv_host_intr(struct ata_host *host, u32 main_irq_cause)
{
        struct mv_host_priv *hpriv = host->private_data;
        void __iomem *mmio = hpriv->base, *hc_mmio;
        unsigned int handled = 0, port;

        /* If asserted, clear the "all ports" IRQ coalescing bit */
        if (main_irq_cause & ALL_PORTS_COAL_DONE)
                writel(~ALL_PORTS_COAL_IRQ, mmio + IRQ_COAL_CAUSE);

        for (port = 0; port < hpriv->n_ports; port++) {
                struct ata_port *ap = host->ports[port];
                unsigned int p, shift, hardport, port_cause;

                MV_PORT_TO_SHIFT_AND_HARDPORT(port, shift, hardport);
                /*
                 * Each hc within the host has its own hc_irq_cause register,
                 * where the interrupting ports bits get ack'd.
                 */
                if (hardport == 0) {    /* first port on this hc ? */
                        u32 hc_cause = (main_irq_cause >> shift) & HC0_IRQ_PEND;
                        u32 port_mask, ack_irqs;
                        /*
                         * Skip this entire hc if nothing pending for any ports
                         */
                        if (!hc_cause) {
                                port += MV_PORTS_PER_HC - 1;
                                continue;
                        }
                        /*
                         * We don't need/want to read the hc_irq_cause register,
                         * because doing so hurts performance, and
                         * main_irq_cause already gives us everything we need.
                         *
                         * But we do have to *write* to the hc_irq_cause to ack
                         * the ports that we are handling this time through.
                         *
                         * This requires that we create a bitmap for those
                         * ports which interrupted us, and use that bitmap
                         * to ack (only) those ports via hc_irq_cause.
                         */
                        ack_irqs = 0;
                        if (hc_cause & PORTS_0_3_COAL_DONE)
                                ack_irqs = HC_COAL_IRQ;
                        for (p = 0; p < MV_PORTS_PER_HC; ++p) {
                                if ((port + p) >= hpriv->n_ports)
                                        break;
                                port_mask = (DONE_IRQ | ERR_IRQ) << (p * 2);
                                if (hc_cause & port_mask)
                                        ack_irqs |= (DMA_IRQ | DEV_IRQ) << p;
                        }
                        hc_mmio = mv_hc_base_from_port(mmio, port);
                        writelfl(~ack_irqs, hc_mmio + HC_IRQ_CAUSE);
                        handled = 1;
                }
                /*
                 * Handle interrupts signalled for this port:
                 */
                port_cause = (main_irq_cause >> shift) & (DONE_IRQ | ERR_IRQ);
                if (port_cause)
                        mv_port_intr(ap, port_cause);
        }
        return handled;
}

static int mv_pci_error(struct ata_host *host, void __iomem *mmio)
{
        struct mv_host_priv *hpriv = host->private_data;
        struct ata_port *ap;
        struct ata_queued_cmd *qc;
        struct ata_eh_info *ehi;
        unsigned int i, err_mask, printed = 0;
        u32 err_cause;

        err_cause = readl(mmio + hpriv->irq_cause_offset);

        dev_printk(KERN_ERR, host->dev, "PCI ERROR; PCI IRQ cause=0x%08x\n",
                   err_cause);

        DPRINTK("All regs @ PCI error\n");
        mv_dump_all_regs(mmio, -1, to_pci_dev(host->dev));

        writelfl(0, mmio + hpriv->irq_cause_offset);

        for (i = 0; i < host->n_ports; i++) {
                ap = host->ports[i];
                if (!ata_link_offline(&ap->link)) {
                        ehi = &ap->link.eh_info;
                        ata_ehi_clear_desc(ehi);
                        if (!printed++)
                                ata_ehi_push_desc(ehi,
                                        "PCI err cause 0x%08x", err_cause);
                        err_mask = AC_ERR_HOST_BUS;
                        ehi->action = ATA_EH_RESET;
                        qc = ata_qc_from_tag(ap, ap->link.active_tag);
                        if (qc)
                                qc->err_mask |= err_mask;
                        else
                                ehi->err_mask |= err_mask;

                        ata_port_freeze(ap);
                }
        }
        return 1;       /* handled */
}

/**
 *      mv_interrupt - Main interrupt event handler
 *      @irq: unused
 *      @dev_instance: private data; in this case the host structure
 *
 *      Read the read only register to determine if any host
 *      controllers have pending interrupts.  If so, call lower level
 *      routine to handle.  Also check for PCI errors which are only
 *      reported here.
 *
 *      LOCKING:
 *      This routine holds the host lock while processing pending
 *      interrupts.
 */
static irqreturn_t mv_interrupt(int irq, void *dev_instance)
{
        struct ata_host *host = dev_instance;
        struct mv_host_priv *hpriv = host->private_data;
        unsigned int handled = 0;
        int using_msi = hpriv->hp_flags & MV_HP_FLAG_MSI;
        u32 main_irq_cause, pending_irqs;

        spin_lock(&host->lock);

        /* for MSI:  block new interrupts while in here */
        if (using_msi)
                mv_write_main_irq_mask(0, hpriv);

        main_irq_cause = readl(hpriv->main_irq_cause_addr);
        pending_irqs   = main_irq_cause & hpriv->main_irq_mask;
        /*
         * Deal with cases where we either have nothing pending, or have read
         * a bogus register value which can indicate HW removal or PCI fault.
         */
        if (pending_irqs && main_irq_cause != 0xffffffffU) {
                if (unlikely((pending_irqs & PCI_ERR) && !IS_SOC(hpriv)))
                        handled = mv_pci_error(host, hpriv->base);
                else
                        handled = mv_host_intr(host, pending_irqs);
        }

        /* for MSI: unmask; interrupt cause bits will retrigger now */
        if (using_msi)
                mv_write_main_irq_mask(hpriv->main_irq_mask, hpriv);

        spin_unlock(&host->lock);

        return IRQ_RETVAL(handled);
}

static unsigned int mv5_scr_offset(unsigned int sc_reg_in)
{
        unsigned int ofs;

        switch (sc_reg_in) {
        case SCR_STATUS:
        case SCR_ERROR:
        case SCR_CONTROL:
                ofs = sc_reg_in * sizeof(u32);
                break;
        default:
                ofs = 0xffffffffU;
                break;
        }
        return ofs;
}

static int mv5_scr_read(struct ata_link *link, unsigned int sc_reg_in, u32 *val)
{
        struct mv_host_priv *hpriv = link->ap->host->private_data;
        void __iomem *mmio = hpriv->base;
        void __iomem *addr = mv5_phy_base(mmio, link->ap->port_no);
        unsigned int ofs = mv5_scr_offset(sc_reg_in);

        if (ofs != 0xffffffffU) {
                *val = readl(addr + ofs);
                return 0;
        } else
                return -EINVAL;
}

static int mv5_scr_write(struct ata_link *link, unsigned int sc_reg_in, u32 val)
{
        struct mv_host_priv *hpriv = link->ap->host->private_data;
        void __iomem *mmio = hpriv->base;
        void __iomem *addr = mv5_phy_base(mmio, link->ap->port_no);
        unsigned int ofs = mv5_scr_offset(sc_reg_in);

        if (ofs != 0xffffffffU) {
                writelfl(val, addr + ofs);
                return 0;
        } else
                return -EINVAL;
}

static void mv5_reset_bus(struct ata_host *host, void __iomem *mmio)
{
        struct pci_dev *pdev = to_pci_dev(host->dev);
        int early_5080;

        early_5080 = (pdev->device == 0x5080) && (pdev->revision == 0);