x86/amd-iommu: Add function to complete a tlb flush

[linux/fpc-iii.git] / drivers / infiniband / hw / ipath / ipath_sd7220.c

/*
 * Copyright (c) 2006, 2007, 2008 QLogic Corporation. All rights reserved.
 * Copyright (c) 2003, 2004, 2005, 2006 PathScale, Inc. All rights reserved.
 *
 * This software is available to you under a choice of one of two
 * licenses.  You may choose to be licensed under the terms of the GNU
 * General Public License (GPL) Version 2, available from the file
 * COPYING in the main directory of this source tree, or the
 * OpenIB.org BSD license below:
 *
 *     Redistribution and use in source and binary forms, with or
 *     without modification, are permitted provided that the following
 *     conditions are met:
 *
 *      - Redistributions of source code must retain the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer.
 *
 *      - Redistributions in binary form must reproduce the above
 *        copyright notice, this list of conditions and the following
 *        disclaimer in the documentation and/or other materials
 *        provided with the distribution.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 * SOFTWARE.
 */
/*
 * This file contains all of the code that is specific to the SerDes
 * on the InfiniPath 7220 chip.
 */

#include <linux/pci.h>
#include <linux/delay.h>

#include "ipath_kernel.h"
#include "ipath_registers.h"
#include "ipath_7220.h"

/*
 * The IBSerDesMappTable is a memory that holds values to be stored in
 * various SerDes registers by IBC. It is not part of the normal kregs
 * map and is used in exactly one place, hence the #define below.
 */
#define KR_IBSerDesMappTable (0x94000 / (sizeof(uint64_t)))

/*
 * Below used for sdnum parameter, selecting one of the two sections
 * used for PCIe, or the single SerDes used for IB.
 */
#define PCIE_SERDES0 0
#define PCIE_SERDES1 1

/*
 * The EPB requires addressing in a particular form. EPB_LOC() is intended
 * to make #definitions a little more readable.
 */
#define EPB_ADDR_SHF 8
#define EPB_LOC(chn, elt, reg) \
        (((elt & 0xf) | ((chn & 7) << 4) | ((reg & 0x3f) << 9)) << \
         EPB_ADDR_SHF)
#define EPB_IB_QUAD0_CS_SHF (25)
#define EPB_IB_QUAD0_CS (1U <<  EPB_IB_QUAD0_CS_SHF)
#define EPB_IB_UC_CS_SHF (26)
#define EPB_PCIE_UC_CS_SHF (27)
#define EPB_GLOBAL_WR (1U << (EPB_ADDR_SHF + 8))

/* Forward declarations. */
static int ipath_sd7220_reg_mod(struct ipath_devdata *dd, int sdnum, u32 loc,
                                u32 data, u32 mask);
static int ibsd_mod_allchnls(struct ipath_devdata *dd, int loc, int val,
                             int mask);
static int ipath_sd_trimdone_poll(struct ipath_devdata *dd);
static void ipath_sd_trimdone_monitor(struct ipath_devdata *dd,
                                      const char *where);
static int ipath_sd_setvals(struct ipath_devdata *dd);
static int ipath_sd_early(struct ipath_devdata *dd);
static int ipath_sd_dactrim(struct ipath_devdata *dd);
/* Set the registers that IBC may muck with to their default "preset" values */
int ipath_sd7220_presets(struct ipath_devdata *dd);
static int ipath_internal_presets(struct ipath_devdata *dd);
/* Tweak the register (CMUCTRL5) that contains the TRIMSELF controls */
static int ipath_sd_trimself(struct ipath_devdata *dd, int val);
static int epb_access(struct ipath_devdata *dd, int sdnum, int claim);

void ipath_set_relock_poll(struct ipath_devdata *dd, int ibup);

/*
 * Below keeps track of whether the "once per power-on" initialization has
 * been done, because uC code Version 1.32.17 or higher allows the uC to
 * be reset at will, and Automatic Equalization may require it. So the
 * state of the reset "pin", as reflected in was_reset parameter to
 * ipath_sd7220_init() is no longer valid. Instead, we check for the
 * actual uC code having been loaded.
 */
static int ipath_ibsd_ucode_loaded(struct ipath_devdata *dd)
{
        if (!dd->serdes_first_init_done && (ipath_sd7220_ib_vfy(dd) > 0))
                dd->serdes_first_init_done = 1;
        return dd->serdes_first_init_done;
}

/* repeat #define for local use. "Real" #define is in ipath_iba7220.c */
#define INFINIPATH_HWE_IB_UC_MEMORYPARITYERR      0x0000004000000000ULL
#define IB_MPREG5 (EPB_LOC(6, 0, 0xE) | (1L << EPB_IB_UC_CS_SHF))
#define IB_MPREG6 (EPB_LOC(6, 0, 0xF) | (1U << EPB_IB_UC_CS_SHF))
#define UC_PAR_CLR_D 8
#define UC_PAR_CLR_M 0xC
#define IB_CTRL2(chn) (EPB_LOC(chn, 7, 3) | EPB_IB_QUAD0_CS)
#define START_EQ1(chan) EPB_LOC(chan, 7, 0x27)

void ipath_sd7220_clr_ibpar(struct ipath_devdata *dd)
{
        int ret;

        /* clear, then re-enable parity errs */
        ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, IB_MPREG6,
                UC_PAR_CLR_D, UC_PAR_CLR_M);
        if (ret < 0) {
                ipath_dev_err(dd, "Failed clearing IBSerDes Parity err\n");
                goto bail;
        }
        ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, IB_MPREG6, 0,
                UC_PAR_CLR_M);

        ipath_read_kreg32(dd, dd->ipath_kregs->kr_scratch);
        udelay(4);
        ipath_write_kreg(dd, dd->ipath_kregs->kr_hwerrclear,
                INFINIPATH_HWE_IB_UC_MEMORYPARITYERR);
        ipath_read_kreg32(dd, dd->ipath_kregs->kr_scratch);
bail:
        return;
}

/*
 * After a reset or other unusual event, the epb interface may need
 * to be re-synchronized, between the host and the uC.
 * returns <0 for failure to resync within IBSD_RESYNC_TRIES (not expected)
 */
#define IBSD_RESYNC_TRIES 3
#define IB_PGUDP(chn) (EPB_LOC((chn), 2, 1) | EPB_IB_QUAD0_CS)
#define IB_CMUDONE(chn) (EPB_LOC((chn), 7, 0xF) | EPB_IB_QUAD0_CS)

static int ipath_resync_ibepb(struct ipath_devdata *dd)
{
        int ret, pat, tries, chn;
        u32 loc;

        ret = -1;
        chn = 0;
        for (tries = 0; tries < (4 * IBSD_RESYNC_TRIES); ++tries) {
                loc = IB_PGUDP(chn);
                ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, loc, 0, 0);
                if (ret < 0) {
                        ipath_dev_err(dd, "Failed read in resync\n");
                        continue;
                }
                if (ret != 0xF0 && ret != 0x55 && tries == 0)
                        ipath_dev_err(dd, "unexpected pattern in resync\n");
                pat = ret ^ 0xA5; /* alternate F0 and 55 */
                ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, loc, pat, 0xFF);
                if (ret < 0) {
                        ipath_dev_err(dd, "Failed write in resync\n");
                        continue;
                }
                ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, loc, 0, 0);
                if (ret < 0) {
                        ipath_dev_err(dd, "Failed re-read in resync\n");
                        continue;
                }
                if (ret != pat) {
                        ipath_dev_err(dd, "Failed compare1 in resync\n");
                        continue;
                }
                loc = IB_CMUDONE(chn);
                ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, loc, 0, 0);
                if (ret < 0) {
                        ipath_dev_err(dd, "Failed CMUDONE rd in resync\n");
                        continue;
                }
                if ((ret & 0x70) != ((chn << 4) | 0x40)) {
                        ipath_dev_err(dd, "Bad CMUDONE value %02X, chn %d\n",
                                ret, chn);
                        continue;
                }
                if (++chn == 4)
                        break;  /* Success */
        }
        ipath_cdbg(VERBOSE, "Resync in %d tries\n", tries);
        return (ret > 0) ? 0 : ret;
}

/*
 * Localize the stuff that should be done to change IB uC reset
 * returns <0 for errors.
 */
static int ipath_ibsd_reset(struct ipath_devdata *dd, int assert_rst)
{
        u64 rst_val;
        int ret = 0;
        unsigned long flags;

        rst_val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_ibserdesctrl);
        if (assert_rst) {
                /*
                 * Vendor recommends "interrupting" uC before reset, to
                 * minimize possible glitches.
                 */
                spin_lock_irqsave(&dd->ipath_sdepb_lock, flags);
                epb_access(dd, IB_7220_SERDES, 1);
                rst_val |= 1ULL;
                /* Squelch possible parity error from _asserting_ reset */
                ipath_write_kreg(dd, dd->ipath_kregs->kr_hwerrmask,
                        dd->ipath_hwerrmask &
                        ~INFINIPATH_HWE_IB_UC_MEMORYPARITYERR);
                ipath_write_kreg(dd, dd->ipath_kregs->kr_ibserdesctrl, rst_val);
                /* flush write, delay to ensure it took effect */
                ipath_read_kreg32(dd, dd->ipath_kregs->kr_scratch);
                udelay(2);
                /* once it's reset, can remove interrupt */
                epb_access(dd, IB_7220_SERDES, -1);
                spin_unlock_irqrestore(&dd->ipath_sdepb_lock, flags);
        } else {
                /*
                 * Before we de-assert reset, we need to deal with
                 * possible glitch on the Parity-error line.
                 * Suppress it around the reset, both in chip-level
                 * hwerrmask and in IB uC control reg. uC will allow
                 * it again during startup.
                 */
                u64 val;
                rst_val &= ~(1ULL);
                ipath_write_kreg(dd, dd->ipath_kregs->kr_hwerrmask,
                        dd->ipath_hwerrmask &
                        ~INFINIPATH_HWE_IB_UC_MEMORYPARITYERR);

                ret = ipath_resync_ibepb(dd);
                if (ret < 0)
                        ipath_dev_err(dd, "unable to re-sync IB EPB\n");

                /* set uC control regs to suppress parity errs */
                ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, IB_MPREG5, 1, 1);
                if (ret < 0)
                        goto bail;
                /* IB uC code past Version 1.32.17 allow suppression of wdog */
                ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, IB_MPREG6, 0x80,
                        0x80);
                if (ret < 0) {
                        ipath_dev_err(dd, "Failed to set WDOG disable\n");
                        goto bail;
                }
                ipath_write_kreg(dd, dd->ipath_kregs->kr_ibserdesctrl, rst_val);
                /* flush write, delay for startup */
                ipath_read_kreg32(dd, dd->ipath_kregs->kr_scratch);
                udelay(1);
                /* clear, then re-enable parity errs */
                ipath_sd7220_clr_ibpar(dd);
                val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_hwerrstatus);
                if (val & INFINIPATH_HWE_IB_UC_MEMORYPARITYERR) {
                        ipath_dev_err(dd, "IBUC Parity still set after RST\n");
                        dd->ipath_hwerrmask &=
                                ~INFINIPATH_HWE_IB_UC_MEMORYPARITYERR;
                }
                ipath_write_kreg(dd, dd->ipath_kregs->kr_hwerrmask,
                        dd->ipath_hwerrmask);
        }

bail:
        return ret;
}

static void ipath_sd_trimdone_monitor(struct ipath_devdata *dd,
       const char *where)
{
        int ret, chn, baduns;
        u64 val;

        if (!where)
                where = "?";

        /* give time for reset to settle out in EPB */
        udelay(2);

        ret = ipath_resync_ibepb(dd);
        if (ret < 0)
                ipath_dev_err(dd, "not able to re-sync IB EPB (%s)\n", where);

        /* Do "sacrificial read" to get EPB in sane state after reset */
        ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, IB_CTRL2(0), 0, 0);
        if (ret < 0)
                ipath_dev_err(dd, "Failed TRIMDONE 1st read, (%s)\n", where);

        /* Check/show "summary" Trim-done bit in IBCStatus */
        val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_ibcstatus);
        if (val & (1ULL << 11))
                ipath_cdbg(VERBOSE, "IBCS TRIMDONE set (%s)\n", where);
        else
                ipath_dev_err(dd, "IBCS TRIMDONE clear (%s)\n", where);

        udelay(2);

        ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, IB_MPREG6, 0x80, 0x80);
        if (ret < 0)
                ipath_dev_err(dd, "Failed Dummy RMW, (%s)\n", where);
        udelay(10);

        baduns = 0;

        for (chn = 3; chn >= 0; --chn) {
                /* Read CTRL reg for each channel to check TRIMDONE */
                ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES,
                        IB_CTRL2(chn), 0, 0);
                if (ret < 0)
                        ipath_dev_err(dd, "Failed checking TRIMDONE, chn %d"
                                " (%s)\n", chn, where);

                if (!(ret & 0x10)) {
                        int probe;
                        baduns |= (1 << chn);
                        ipath_dev_err(dd, "TRIMDONE cleared on chn %d (%02X)."
                                " (%s)\n", chn, ret, where);
                        probe = ipath_sd7220_reg_mod(dd, IB_7220_SERDES,
                                IB_PGUDP(0), 0, 0);
                        ipath_dev_err(dd, "probe is %d (%02X)\n",
                                probe, probe);
                        probe = ipath_sd7220_reg_mod(dd, IB_7220_SERDES,
                                IB_CTRL2(chn), 0, 0);
                        ipath_dev_err(dd, "re-read: %d (%02X)\n",
                                probe, probe);
                        ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES,
                                IB_CTRL2(chn), 0x10, 0x10);
                        if (ret < 0)
                                ipath_dev_err(dd,
                                        "Err on TRIMDONE rewrite1\n");
                }
        }
        for (chn = 3; chn >= 0; --chn) {
                /* Read CTRL reg for each channel to check TRIMDONE */
                if (baduns & (1 << chn)) {
                        ipath_dev_err(dd,
                                "Reseting TRIMDONE on chn %d (%s)\n",
                                chn, where);
                        ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES,
                                IB_CTRL2(chn), 0x10, 0x10);
                        if (ret < 0)
                                ipath_dev_err(dd, "Failed re-setting "
                                        "TRIMDONE, chn %d (%s)\n",
                                        chn, where);
                }
        }
}

/*
 * Below is portion of IBA7220-specific bringup_serdes() that actually
 * deals with registers and memory within the SerDes itself.
 * Post IB uC code version 1.32.17, was_reset being 1 is not really
 * informative, so we double-check.
 */
int ipath_sd7220_init(struct ipath_devdata *dd, int was_reset)
{
        int ret = 1; /* default to failure */
        int first_reset;
        int val_stat;

        if (!was_reset) {
                /* entered with reset not asserted, we need to do it */
                ipath_ibsd_reset(dd, 1);
                ipath_sd_trimdone_monitor(dd, "Driver-reload");
        }

        /* Substitute our deduced value for was_reset */
        ret = ipath_ibsd_ucode_loaded(dd);
        if (ret < 0) {
                ret = 1;
                goto done;
        }
        first_reset = !ret; /* First reset if IBSD uCode not yet loaded */

        /*
         * Alter some regs per vendor latest doc, reset-defaults
         * are not right for IB.
         */
        ret = ipath_sd_early(dd);
        if (ret < 0) {
                ipath_dev_err(dd, "Failed to set IB SERDES early defaults\n");
                ret = 1;
                goto done;
        }

        /*
         * Set DAC manual trim IB.
         * We only do this once after chip has been reset (usually
         * same as once per system boot).
         */
        if (first_reset) {
                ret = ipath_sd_dactrim(dd);
                if (ret < 0) {
                        ipath_dev_err(dd, "Failed IB SERDES DAC trim\n");
                        ret = 1;
                        goto done;
                }
        }

        /*
         * Set various registers (DDS and RXEQ) that will be
         * controlled by IBC (in 1.2 mode) to reasonable preset values
         * Calling the "internal" version avoids the "check for needed"
         * and "trimdone monitor" that might be counter-productive.
         */
        ret = ipath_internal_presets(dd);
        if (ret < 0) {
                ipath_dev_err(dd, "Failed to set IB SERDES presets\n");
                ret = 1;
                goto done;
        }
        ret = ipath_sd_trimself(dd, 0x80);
        if (ret < 0) {
                ipath_dev_err(dd, "Failed to set IB SERDES TRIMSELF\n");
                ret = 1;
                goto done;
        }

        /* Load image, then try to verify */
        ret = 0;        /* Assume success */
        if (first_reset) {
                int vfy;
                int trim_done;
                ipath_dbg("SerDes uC was reset, reloading PRAM\n");
                ret = ipath_sd7220_ib_load(dd);
                if (ret < 0) {
                        ipath_dev_err(dd, "Failed to load IB SERDES image\n");
                        ret = 1;
                        goto done;
                }

                /* Loaded image, try to verify */
                vfy = ipath_sd7220_ib_vfy(dd);
                if (vfy != ret) {
                        ipath_dev_err(dd, "SERDES PRAM VFY failed\n");
                        ret = 1;
                        goto done;
                }
                /*
                 * Loaded and verified. Almost good...
                 * hold "success" in ret
                 */
                ret = 0;

                /*
                 * Prev steps all worked, continue bringup
                 * De-assert RESET to uC, only in first reset, to allow
                 * trimming.
                 *
                 * Since our default setup sets START_EQ1 to
                 * PRESET, we need to clear that for this very first run.
                 */
                ret = ibsd_mod_allchnls(dd, START_EQ1(0), 0, 0x38);
                if (ret < 0) {
                        ipath_dev_err(dd, "Failed clearing START_EQ1\n");
                        ret = 1;
                        goto done;
                }

                ipath_ibsd_reset(dd, 0);
                /*
                 * If this is not the first reset, trimdone should be set
                 * already.
                 */
                trim_done = ipath_sd_trimdone_poll(dd);
                /*
                 * Whether or not trimdone succeeded, we need to put the
                 * uC back into reset to avoid a possible fight with the
                 * IBC state-machine.
                 */
                ipath_ibsd_reset(dd, 1);

                if (!trim_done) {
                        ipath_dev_err(dd, "No TRIMDONE seen\n");
                        ret = 1;
                        goto done;
                }

                ipath_sd_trimdone_monitor(dd, "First-reset");
                /* Remember so we do not re-do the load, dactrim, etc. */
                dd->serdes_first_init_done = 1;
        }
        /*
         * Setup for channel training and load values for
         * RxEq and DDS in tables used by IBC in IB1.2 mode
         */

        val_stat = ipath_sd_setvals(dd);
        if (val_stat < 0)
                ret = 1;
done:
        /* start relock timer regardless, but start at 1 second */
        ipath_set_relock_poll(dd, -1);
        return ret;
}

#define EPB_ACC_REQ 1
#define EPB_ACC_GNT 0x100
#define EPB_DATA_MASK 0xFF
#define EPB_RD (1ULL << 24)
#define EPB_TRANS_RDY (1ULL << 31)
#define EPB_TRANS_ERR (1ULL << 30)
#define EPB_TRANS_TRIES 5

/*
 * query, claim, release ownership of the EPB (External Parallel Bus)
 * for a specified SERDES.
 * the "claim" parameter is >0 to claim, <0 to release, 0 to query.
 * Returns <0 for errors, >0 if we had ownership, else 0.
 */
static int epb_access(struct ipath_devdata *dd, int sdnum, int claim)
{
        u16 acc;
        u64 accval;
        int owned = 0;
        u64 oct_sel = 0;

        switch (sdnum) {
        case IB_7220_SERDES :
                /*
                 * The IB SERDES "ownership" is fairly simple. A single each
                 * request/grant.
                 */
                acc = dd->ipath_kregs->kr_ib_epbacc;
                break;
        case PCIE_SERDES0 :
        case PCIE_SERDES1 :
                /* PCIe SERDES has two "octants", need to select which */
                acc = dd->ipath_kregs->kr_pcie_epbacc;
                oct_sel = (2 << (sdnum - PCIE_SERDES0));
                break;
        default :
                return 0;
        }

        /* Make sure any outstanding transaction was seen */
        ipath_read_kreg32(dd, dd->ipath_kregs->kr_scratch);
        udelay(15);

        accval = ipath_read_kreg32(dd, acc);

        owned = !!(accval & EPB_ACC_GNT);
        if (claim < 0) {
                /* Need to release */
                u64 pollval;
                /*
                 * The only writeable bits are the request and CS.
                 * Both should be clear
                 */
                u64 newval = 0;
                ipath_write_kreg(dd, acc, newval);
                /* First read after write is not trustworthy */
                pollval = ipath_read_kreg32(dd, acc);
                udelay(5);
                pollval = ipath_read_kreg32(dd, acc);
                if (pollval & EPB_ACC_GNT)
                        owned = -1;
        } else if (claim > 0) {
                /* Need to claim */
                u64 pollval;
                u64 newval = EPB_ACC_REQ | oct_sel;
                ipath_write_kreg(dd, acc, newval);
                /* First read after write is not trustworthy */
                pollval = ipath_read_kreg32(dd, acc);
                udelay(5);
                pollval = ipath_read_kreg32(dd, acc);
                if (!(pollval & EPB_ACC_GNT))
                        owned = -1;
        }
        return owned;
}

/*
 * Lemma to deal with race condition of write..read to epb regs
 */
static int epb_trans(struct ipath_devdata *dd, u16 reg, u64 i_val, u64 *o_vp)
{
        int tries;
        u64 transval;


        ipath_write_kreg(dd, reg, i_val);
        /* Throw away first read, as RDY bit may be stale */
        transval = ipath_read_kreg64(dd, reg);

        for (tries = EPB_TRANS_TRIES; tries; --tries) {
                transval = ipath_read_kreg32(dd, reg);
                if (transval & EPB_TRANS_RDY)
                        break;
                udelay(5);
        }
        if (transval & EPB_TRANS_ERR)
                return -1;
        if (tries > 0 && o_vp)
                *o_vp = transval;
        return tries;
}

/**
 *
 * ipath_sd7220_reg_mod - modify SERDES register
 * @dd: the infinipath device
 * @sdnum: which SERDES to access
 * @loc: location - channel, element, register, as packed by EPB_LOC() macro.
 * @wd: Write Data - value to set in register
 * @mask: ones where data should be spliced into reg.
 *
 * Basic register read/modify/write, with un-needed acesses elided. That is,
 * a mask of zero will prevent write, while a mask of 0xFF will prevent read.
 * returns current (presumed, if a write was done) contents of selected
 * register, or <0 if errors.
 */
static int ipath_sd7220_reg_mod(struct ipath_devdata *dd, int sdnum, u32 loc,
                                u32 wd, u32 mask)
{
        u16 trans;
        u64 transval;
        int owned;
        int tries, ret;
        unsigned long flags;

        switch (sdnum) {
        case IB_7220_SERDES :
                trans = dd->ipath_kregs->kr_ib_epbtrans;
                break;
        case PCIE_SERDES0 :
        case PCIE_SERDES1 :
                trans = dd->ipath_kregs->kr_pcie_epbtrans;
                break;
        default :
                return -1;
        }

        /*
         * All access is locked in software (vs other host threads) and
         * hardware (vs uC access).
         */
        spin_lock_irqsave(&dd->ipath_sdepb_lock, flags);

        owned = epb_access(dd, sdnum, 1);
        if (owned < 0) {
                spin_unlock_irqrestore(&dd->ipath_sdepb_lock, flags);
                return -1;
        }
        ret = 0;
        for (tries = EPB_TRANS_TRIES; tries; --tries) {
                transval = ipath_read_kreg32(dd, trans);
                if (transval & EPB_TRANS_RDY)
                        break;
                udelay(5);
        }

        if (tries > 0) {
                tries = 1;      /* to make read-skip work */
                if (mask != 0xFF) {
                        /*
                         * Not a pure write, so need to read.
                         * loc encodes chip-select as well as address
                         */
                        transval = loc | EPB_RD;
                        tries = epb_trans(dd, trans, transval, &transval);
                }
                if (tries > 0 && mask != 0) {
                        /*
                         * Not a pure read, so need to write.
                         */
                        wd = (wd & mask) | (transval & ~mask);
                        transval = loc | (wd & EPB_DATA_MASK);
                        tries = epb_trans(dd, trans, transval, &transval);
                }
        }
        /* else, failed to see ready, what error-handling? */

        /*
         * Release bus. Failure is an error.
         */
        if (epb_access(dd, sdnum, -1) < 0)
                ret = -1;
        else
                ret = transval & EPB_DATA_MASK;

        spin_unlock_irqrestore(&dd->ipath_sdepb_lock, flags);
        if (tries <= 0)
                ret = -1;
        return ret;
}

#define EPB_ROM_R (2)
#define EPB_ROM_W (1)
/*
 * Below, all uC-related, use appropriate UC_CS, depending
 * on which SerDes is used.
 */
#define EPB_UC_CTL EPB_LOC(6, 0, 0)
#define EPB_MADDRL EPB_LOC(6, 0, 2)
#define EPB_MADDRH EPB_LOC(6, 0, 3)
#define EPB_ROMDATA EPB_LOC(6, 0, 4)
#define EPB_RAMDATA EPB_LOC(6, 0, 5)

/* Transfer date to/from uC Program RAM of IB or PCIe SerDes */
static int ipath_sd7220_ram_xfer(struct ipath_devdata *dd, int sdnum, u32 loc,
                               u8 *buf, int cnt, int rd_notwr)
{
        u16 trans;
        u64 transval;
        u64 csbit;
        int owned;
        int tries;
        int sofar;
        int addr;
        int ret;
        unsigned long flags;
        const char *op;

        /* Pick appropriate transaction reg and "Chip select" for this serdes */
        switch (sdnum) {
        case IB_7220_SERDES :
                csbit = 1ULL << EPB_IB_UC_CS_SHF;
                trans = dd->ipath_kregs->kr_ib_epbtrans;
                break;
        case PCIE_SERDES0 :
        case PCIE_SERDES1 :
                /* PCIe SERDES has uC "chip select" in different bit, too */
                csbit = 1ULL << EPB_PCIE_UC_CS_SHF;
                trans = dd->ipath_kregs->kr_pcie_epbtrans;
                break;
        default :
                return -1;
        }

        op = rd_notwr ? "Rd" : "Wr";
        spin_lock_irqsave(&dd->ipath_sdepb_lock, flags);

        owned = epb_access(dd, sdnum, 1);
        if (owned < 0) {
                spin_unlock_irqrestore(&dd->ipath_sdepb_lock, flags);
                ipath_dbg("Could not get %s access to %s EPB: %X, loc %X\n",
                        op, (sdnum == IB_7220_SERDES) ? "IB" : "PCIe",
                        owned, loc);
                return -1;
        }

        /*
         * In future code, we may need to distinguish several address ranges,
         * and select various memories based on this. For now, just trim
         * "loc" (location including address and memory select) to
         * "addr" (address within memory). we will only support PRAM
         * The memory is 8KB.
         */
        addr = loc & 0x1FFF;
        for (tries = EPB_TRANS_TRIES; tries; --tries) {
                transval = ipath_read_kreg32(dd, trans);
                if (transval & EPB_TRANS_RDY)
                        break;
                udelay(5);
        }

        sofar = 0;
        if (tries <= 0)
                ipath_dbg("No initial RDY on EPB access request\n");
        else {
                /*
                 * Every "memory" access is doubly-indirect.
                 * We set two bytes of address, then read/write
                 * one or mores bytes of data.
                 */

                /* First, we set control to "Read" or "Write" */
                transval = csbit | EPB_UC_CTL |
                        (rd_notwr ? EPB_ROM_R : EPB_ROM_W);
                tries = epb_trans(dd, trans, transval, &transval);
                if (tries <= 0)
                        ipath_dbg("No EPB response to uC %s cmd\n", op);
                while (tries > 0 && sofar < cnt) {
                        if (!sofar) {
                                /* Only set address at start of chunk */
                                int addrbyte = (addr + sofar) >> 8;
                                transval = csbit | EPB_MADDRH | addrbyte;
                                tries = epb_trans(dd, trans, transval,
                                                  &transval);
                                if (tries <= 0) {
                                        ipath_dbg("No EPB response ADDRH\n");
                                        break;
                                }
                                addrbyte = (addr + sofar) & 0xFF;
                                transval = csbit | EPB_MADDRL | addrbyte;
                                tries = epb_trans(dd, trans, transval,
                                                 &transval);
                                if (tries <= 0) {
                                        ipath_dbg("No EPB response ADDRL\n");
                                        break;
                                }
                        }

                        if (rd_notwr)
                                transval = csbit | EPB_ROMDATA | EPB_RD;
                        else
                                transval = csbit | EPB_ROMDATA | buf[sofar];
                        tries = epb_trans(dd, trans, transval, &transval);
                        if (tries <= 0) {
                                ipath_dbg("No EPB response DATA\n");
                                break;
                        }
                        if (rd_notwr)
                                buf[sofar] = transval & EPB_DATA_MASK;
                        ++sofar;
                }
                /* Finally, clear control-bit for Read or Write */
                transval = csbit | EPB_UC_CTL;
                tries = epb_trans(dd, trans, transval, &transval);
                if (tries <= 0)
                        ipath_dbg("No EPB response to drop of uC %s cmd\n", op);
        }

        ret = sofar;
        /* Release bus. Failure is an error */
        if (epb_access(dd, sdnum, -1) < 0)
                ret = -1;

        spin_unlock_irqrestore(&dd->ipath_sdepb_lock, flags);
        if (tries <= 0) {
                ipath_dbg("SERDES PRAM %s failed after %d bytes\n", op, sofar);
                ret = -1;
        }
        return ret;
}

#define PROG_CHUNK 64

int ipath_sd7220_prog_ld(struct ipath_devdata *dd, int sdnum,
        u8 *img, int len, int offset)
{
        int cnt, sofar, req;

        sofar = 0;
        while (sofar < len) {
                req = len - sofar;
                if (req > PROG_CHUNK)
                        req = PROG_CHUNK;
                cnt = ipath_sd7220_ram_xfer(dd, sdnum, offset + sofar,
                                          img + sofar, req, 0);
                if (cnt < req) {
                        sofar = -1;
                        break;
                }
                sofar += req;
        }
        return sofar;
}

#define VFY_CHUNK 64
#define SD_PRAM_ERROR_LIMIT 42

int ipath_sd7220_prog_vfy(struct ipath_devdata *dd, int sdnum,
        const u8 *img, int len, int offset)
{
        int cnt, sofar, req, idx, errors;
        unsigned char readback[VFY_CHUNK];

        errors = 0;
        sofar = 0;
        while (sofar < len) {
                req = len - sofar;
                if (req > VFY_CHUNK)
                        req = VFY_CHUNK;
                cnt = ipath_sd7220_ram_xfer(dd, sdnum, sofar + offset,
                                          readback, req, 1);
                if (cnt < req) {
                        /* failed in read itself */
                        sofar = -1;
                        break;
                }
                for (idx = 0; idx < cnt; ++idx) {
                        if (readback[idx] != img[idx+sofar])
                                ++errors;
                }
                sofar += cnt;
        }
        return errors ? -errors : sofar;
}

/* IRQ not set up at this point in init, so we poll. */
#define IB_SERDES_TRIM_DONE (1ULL << 11)
#define TRIM_TMO (30)

static int ipath_sd_trimdone_poll(struct ipath_devdata *dd)
{
        int trim_tmo, ret;
        uint64_t val;

        /*
         * Default to failure, so IBC will not start
         * without IB_SERDES_TRIM_DONE.
         */
        ret = 0;
        for (trim_tmo = 0; trim_tmo < TRIM_TMO; ++trim_tmo) {
                val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_ibcstatus);
                if (val & IB_SERDES_TRIM_DONE) {
                        ipath_cdbg(VERBOSE, "TRIMDONE after %d\n", trim_tmo);
                        ret = 1;
                        break;
                }
                msleep(10);
        }
        if (trim_tmo >= TRIM_TMO) {
                ipath_dev_err(dd, "No TRIMDONE in %d tries\n", trim_tmo);
                ret = 0;
        }
        return ret;
}

#define TX_FAST_ELT (9)

/*
 * Set the "negotiation" values for SERDES. These are used by the IB1.2
 * link negotiation. Macros below are attempt to keep the values a
 * little more human-editable.
 * First, values related to Drive De-emphasis Settings.
 */

#define NUM_DDS_REGS 6
#define DDS_REG_MAP 0x76A910 /* LSB-first list of regs (in elt 9) to mod */

#define DDS_VAL(amp_d, main_d, ipst_d, ipre_d, amp_s, main_s, ipst_s, ipre_s) \
        { { ((amp_d & 0x1F) << 1) | 1, ((amp_s & 0x1F) << 1) | 1, \
          (main_d << 3) | 4 | (ipre_d >> 2), \
          (main_s << 3) | 4 | (ipre_s >> 2), \
          ((ipst_d & 0xF) << 1) | ((ipre_d & 3) << 6) | 0x21, \
          ((ipst_s & 0xF) << 1) | ((ipre_s & 3) << 6) | 0x21 } }

static struct dds_init {
        uint8_t reg_vals[NUM_DDS_REGS];
} dds_init_vals[] = {
        /*       DDR(FDR)       SDR(HDR)   */
        /* Vendor recommends below for 3m cable */
#define DDS_3M 0
        DDS_VAL(31, 19, 12, 0, 29, 22,  9, 0),
        DDS_VAL(31, 12, 15, 4, 31, 15, 15, 1),
        DDS_VAL(31, 13, 15, 3, 31, 16, 15, 0),
        DDS_VAL(31, 14, 15, 2, 31, 17, 14, 0),
        DDS_VAL(31, 15, 15, 1, 31, 18, 13, 0),
        DDS_VAL(31, 16, 15, 0, 31, 19, 12, 0),
        DDS_VAL(31, 17, 14, 0, 31, 20, 11, 0),
        DDS_VAL(31, 18, 13, 0, 30, 21, 10, 0),
        DDS_VAL(31, 20, 11, 0, 28, 23,  8, 0),
        DDS_VAL(31, 21, 10, 0, 27, 24,  7, 0),
        DDS_VAL(31, 22,  9, 0, 26, 25,  6, 0),
        DDS_VAL(30, 23,  8, 0, 25, 26,  5, 0),
        DDS_VAL(29, 24,  7, 0, 23, 27,  4, 0),
        /* Vendor recommends below for 1m cable */
#define DDS_1M 13
        DDS_VAL(28, 25,  6, 0, 21, 28,  3, 0),
        DDS_VAL(27, 26,  5, 0, 19, 29,  2, 0),
        DDS_VAL(25, 27,  4, 0, 17, 30,  1, 0)
};

/*
 * Next, values related to Receive Equalization.
 * In comments, FDR (Full) is IB DDR, HDR (Half) is IB SDR
 */
/* Hardware packs an element number and register address thus: */
#define RXEQ_INIT_RDESC(elt, addr) (((elt) & 0xF) | ((addr) << 4))
#define RXEQ_VAL(elt, adr, val0, val1, val2, val3) \
        {RXEQ_INIT_RDESC((elt), (adr)), {(val0), (val1), (val2), (val3)} }

#define RXEQ_VAL_ALL(elt, adr, val)  \
        {RXEQ_INIT_RDESC((elt), (adr)), {(val), (val), (val), (val)} }

#define RXEQ_SDR_DFELTH 0
#define RXEQ_SDR_TLTH 0
#define RXEQ_SDR_G1CNT_Z1CNT 0x11
#define RXEQ_SDR_ZCNT 23

static struct rxeq_init {
        u16 rdesc;      /* in form used in SerDesDDSRXEQ */
        u8  rdata[4];
} rxeq_init_vals[] = {
        /* Set Rcv Eq. to Preset node */
        RXEQ_VAL_ALL(7, 0x27, 0x10),
        /* Set DFELTHFDR/HDR thresholds */
        RXEQ_VAL(7, 8,    0, 0, 0, 0), /* FDR */
        RXEQ_VAL(7, 0x21, 0, 0, 0, 0), /* HDR */
        /* Set TLTHFDR/HDR theshold */
        RXEQ_VAL(7, 9,    2, 2, 2, 2), /* FDR */
        RXEQ_VAL(7, 0x23, 2, 2, 2, 2), /* HDR */
        /* Set Preamp setting 2 (ZFR/ZCNT) */
        RXEQ_VAL(7, 0x1B, 12, 12, 12, 12), /* FDR */
        RXEQ_VAL(7, 0x1C, 12, 12, 12, 12), /* HDR */
        /* Set Preamp DC gain and Setting 1 (GFR/GHR) */
        RXEQ_VAL(7, 0x1E, 0x10, 0x10, 0x10, 0x10), /* FDR */
        RXEQ_VAL(7, 0x1F, 0x10, 0x10, 0x10, 0x10), /* HDR */
        /* Toggle RELOCK (in VCDL_CTRL0) to lock to data */
        RXEQ_VAL_ALL(6, 6, 0x20), /* Set D5 High */
        RXEQ_VAL_ALL(6, 6, 0), /* Set D5 Low */
};

/* There are 17 values from vendor, but IBC only accesses the first 16 */
#define DDS_ROWS (16)
#define RXEQ_ROWS ARRAY_SIZE(rxeq_init_vals)

static int ipath_sd_setvals(struct ipath_devdata *dd)
{
        int idx, midx;
        int min_idx;     /* Minimum index for this portion of table */
        uint32_t dds_reg_map;
        u64 __iomem *taddr, *iaddr;
        uint64_t data;
        uint64_t sdctl;

        taddr = dd->ipath_kregbase + KR_IBSerDesMappTable;
        iaddr = dd->ipath_kregbase + dd->ipath_kregs->kr_ib_ddsrxeq;

        /*
         * Init the DDS section of the table.
         * Each "row" of the table provokes NUM_DDS_REG writes, to the
         * registers indicated in DDS_REG_MAP.
         */
        sdctl = ipath_read_kreg64(dd, dd->ipath_kregs->kr_ibserdesctrl);
        sdctl = (sdctl & ~(0x1f << 8)) | (NUM_DDS_REGS << 8);
        sdctl = (sdctl & ~(0x1f << 13)) | (RXEQ_ROWS << 13);
        ipath_write_kreg(dd, dd->ipath_kregs->kr_ibserdesctrl, sdctl);

        /*
         * Iterate down table within loop for each register to store.
         */
        dds_reg_map = DDS_REG_MAP;
        for (idx = 0; idx < NUM_DDS_REGS; ++idx) {
                data = ((dds_reg_map & 0xF) << 4) | TX_FAST_ELT;
                writeq(data, iaddr + idx);
                mmiowb();
                ipath_read_kreg32(dd, dd->ipath_kregs->kr_scratch);
                dds_reg_map >>= 4;
                for (midx = 0; midx < DDS_ROWS; ++midx) {
                        u64 __iomem *daddr = taddr + ((midx << 4) + idx);
                        data = dds_init_vals[midx].reg_vals[idx];
                        writeq(data, daddr);
                        mmiowb();
                        ipath_read_kreg32(dd, dd->ipath_kregs->kr_scratch);
                } /* End inner for (vals for this reg, each row) */
        } /* end outer for (regs to be stored) */

        /*
         * Init the RXEQ section of the table. As explained above the table
         * rxeq_init_vals[], this runs in a different order, as the pattern
         * of register references is more complex, but there are only
         * four "data" values per register.
         */
        min_idx = idx; /* RXEQ indices pick up where DDS left off */
        taddr += 0x100; /* RXEQ data is in second half of table */
        /* Iterate through RXEQ register addresses */
        for (idx = 0; idx < RXEQ_ROWS; ++idx) {
                int didx; /* "destination" */
                int vidx;

                /* didx is offset by min_idx to address RXEQ range of regs */
                didx = idx + min_idx;
                /* Store the next RXEQ register address */
                writeq(rxeq_init_vals[idx].rdesc, iaddr + didx);
                mmiowb();
                ipath_read_kreg32(dd, dd->ipath_kregs->kr_scratch);
                /* Iterate through RXEQ values */
                for (vidx = 0; vidx < 4; vidx++) {
                        data = rxeq_init_vals[idx].rdata[vidx];
                        writeq(data, taddr + (vidx << 6) + idx);
                        mmiowb();
                        ipath_read_kreg32(dd, dd->ipath_kregs->kr_scratch);
                }
        } /* end outer for (Reg-writes for RXEQ) */
        return 0;
}

#define CMUCTRL5 EPB_LOC(7, 0, 0x15)
#define RXHSCTRL0(chan) EPB_LOC(chan, 6, 0)
#define VCDL_DAC2(chan) EPB_LOC(chan, 6, 5)
#define VCDL_CTRL0(chan) EPB_LOC(chan, 6, 6)
#define VCDL_CTRL2(chan) EPB_LOC(chan, 6, 8)
#define START_EQ2(chan) EPB_LOC(chan, 7, 0x28)

static int ibsd_sto_noisy(struct ipath_devdata *dd, int loc, int val, int mask)
{
        int ret = -1;
        int sloc; /* shifted loc, for messages */

        loc |= (1U << EPB_IB_QUAD0_CS_SHF);
        sloc = loc >> EPB_ADDR_SHF;

        ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, loc, val, mask);
        if (ret < 0)
                ipath_dev_err(dd, "Write failed: elt %d,"
                        " addr 0x%X, chnl %d, val 0x%02X, mask 0x%02X\n",
                        (sloc & 0xF), (sloc >> 9) & 0x3f, (sloc >> 4) & 7,
                        val & 0xFF, mask & 0xFF);
        return ret;
}

/*
 * Repeat a "store" across all channels of the IB SerDes.
 * Although nominally it inherits the "read value" of the last
 * channel it modified, the only really useful return is <0 for
 * failure, >= 0 for success. The parameter 'loc' is assumed to
 * be the location for the channel-0 copy of the register to
 * be modified.
 */
static int ibsd_mod_allchnls(struct ipath_devdata *dd, int loc, int val,
        int mask)
{
        int ret = -1;
        int chnl;

        if (loc & EPB_GLOBAL_WR) {
                /*
                 * Our caller has assured us that we can set all four
                 * channels at once. Trust that. If mask is not 0xFF,
                 * we will read the _specified_ channel for our starting
                 * value.
                 */
                loc |= (1U << EPB_IB_QUAD0_CS_SHF);
                chnl = (loc >> (4 + EPB_ADDR_SHF)) & 7;
                if (mask != 0xFF) {
                        ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES,
                                loc & ~EPB_GLOBAL_WR, 0, 0);
                        if (ret < 0) {
                                int sloc = loc >> EPB_ADDR_SHF;
                                ipath_dev_err(dd, "pre-read failed: elt %d,"
                                        " addr 0x%X, chnl %d\n", (sloc & 0xF),
                                        (sloc >> 9) & 0x3f, chnl);
                                return ret;
                        }
                        val = (ret & ~mask) | (val & mask);
                }
                loc &=  ~(7 << (4+EPB_ADDR_SHF));
                ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, loc, val, 0xFF);
                if (ret < 0) {
                        int sloc = loc >> EPB_ADDR_SHF;
                        ipath_dev_err(dd, "Global WR failed: elt %d,"
                                " addr 0x%X, val %02X\n",
                                (sloc & 0xF), (sloc >> 9) & 0x3f, val);
                }
                return ret;
        }
        /* Clear "channel" and set CS so we can simply iterate */
        loc &=  ~(7 << (4+EPB_ADDR_SHF));
        loc |= (1U << EPB_IB_QUAD0_CS_SHF);
        for (chnl = 0; chnl < 4; ++chnl) {
                int cloc;
                cloc = loc | (chnl << (4+EPB_ADDR_SHF));
                ret = ipath_sd7220_reg_mod(dd, IB_7220_SERDES, cloc, val, mask);
                if (ret < 0) {
                        int sloc = loc >> EPB_ADDR_SHF;
                        ipath_dev_err(dd, "Write failed: elt %d,"
                                " addr 0x%X, chnl %d, val 0x%02X,"
                                " mask 0x%02X\n",
                                (sloc & 0xF), (sloc >> 9) & 0x3f, chnl,
                                val & 0xFF, mask & 0xFF);
                        break;
                }
        }
        return ret;
}

/*
 * Set the Tx values normally modified by IBC in IB1.2 mode to default
 * values, as gotten from first row of init table.
 */
static int set_dds_vals(struct ipath_devdata *dd, struct dds_init *ddi)
{
        int ret;
        int idx, reg, data;
        uint32_t regmap;

        regmap = DDS_REG_MAP;
        for (idx = 0; idx < NUM_DDS_REGS; ++idx) {
                reg = (regmap & 0xF);
                regmap >>= 4;
                data = ddi->reg_vals[idx];
                /* Vendor says RMW not needed for these regs, use 0xFF mask */
                ret = ibsd_mod_allchnls(dd, EPB_LOC(0, 9, reg), data, 0xFF);
                if (ret < 0)
                        break;
        }
        return ret;
}

/*
 * Set the Rx values normally modified by IBC in IB1.2 mode to default
 * values, as gotten from selected column of init table.
 */
static int set_rxeq_vals(struct ipath_devdata *dd, int vsel)
{
        int ret;
        int ridx;
        int cnt = ARRAY_SIZE(rxeq_init_vals);

        for (ridx = 0; ridx < cnt; ++ridx) {
                int elt, reg, val, loc;
                elt = rxeq_init_vals[ridx].rdesc & 0xF;
                reg = rxeq_init_vals[ridx].rdesc >> 4;
                loc = EPB_LOC(0, elt, reg);
                val = rxeq_init_vals[ridx].rdata[vsel];
                /* mask of 0xFF, because hardware does full-byte store. */
                ret = ibsd_mod_allchnls(dd, loc, val, 0xFF);
                if (ret < 0)
                        break;
        }
        return ret;
}

/*
 * Set the default values (row 0) for DDR Driver Demphasis.
 * we do this initially and whenever we turn off IB-1.2
 * The "default" values for Rx equalization are also stored to
 * SerDes registers. Formerly (and still default), we used set 2.
 * For experimenting with cables and link-partners, we allow changing
 * that via a module parameter.
 */
static unsigned ipath_rxeq_set = 2;
module_param_named(rxeq_default_set, ipath_rxeq_set, uint,
        S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(rxeq_default_set,
        "Which set [0..3] of Rx Equalization values is default");

static int ipath_internal_presets(struct ipath_devdata *dd)
{
        int ret = 0;

        ret = set_dds_vals(dd, dds_init_vals + DDS_3M);

        if (ret < 0)
                ipath_dev_err(dd, "Failed to set default DDS values\n");
        ret = set_rxeq_vals(dd, ipath_rxeq_set & 3);
        if (ret < 0)
                ipath_dev_err(dd, "Failed to set default RXEQ values\n");
        return ret;
}

int ipath_sd7220_presets(struct ipath_devdata *dd)
{
        int ret = 0;

        if (!dd->ipath_presets_needed)
                return ret;
        dd->ipath_presets_needed = 0;
        /* Assert uC reset, so we don't clash with it. */
        ipath_ibsd_reset(dd, 1);
        udelay(2);
        ipath_sd_trimdone_monitor(dd, "link-down");

        ret = ipath_internal_presets(dd);
return ret;
}

static int ipath_sd_trimself(struct ipath_devdata *dd, int val)
{
        return ibsd_sto_noisy(dd, CMUCTRL5, val, 0xFF);
}

static int ipath_sd_early(struct ipath_devdata *dd)
{
        int ret = -1; /* Default failed */
        int chnl;

        for (chnl = 0; chnl < 4; ++chnl) {
                ret = ibsd_sto_noisy(dd, RXHSCTRL0(chnl), 0xD4, 0xFF);
                if (ret < 0)
                        goto bail;
        }
        for (chnl = 0; chnl < 4; ++chnl) {
                ret = ibsd_sto_noisy(dd, VCDL_DAC2(chnl), 0x2D, 0xFF);
                if (ret < 0)
                        goto bail;
        }
        /* more fine-tuning of what will be default */
        for (chnl = 0; chnl < 4; ++chnl) {
                ret = ibsd_sto_noisy(dd, VCDL_CTRL2(chnl), 3, 0xF);
                if (ret < 0)
                        goto bail;
        }
        for (chnl = 0; chnl < 4; ++chnl) {
                ret = ibsd_sto_noisy(dd, START_EQ1(chnl), 0x10, 0xFF);
                if (ret < 0)
                        goto bail;
        }
        for (chnl = 0; chnl < 4; ++chnl) {
                ret = ibsd_sto_noisy(dd, START_EQ2(chnl), 0x30, 0xFF);
                if (ret < 0)
                        goto bail;
        }
bail:
        return ret;
}

#define BACTRL(chnl) EPB_LOC(chnl, 6, 0x0E)
#define LDOUTCTRL1(chnl) EPB_LOC(chnl, 7, 6)
#define RXHSSTATUS(chnl) EPB_LOC(chnl, 6, 0xF)

static int ipath_sd_dactrim(struct ipath_devdata *dd)
{
        int ret = -1; /* Default failed */
        int chnl;

        for (chnl = 0; chnl < 4; ++chnl) {
                ret = ibsd_sto_noisy(dd, BACTRL(chnl), 0x40, 0xFF);
                if (ret < 0)
                        goto bail;
        }
        for (chnl = 0; chnl < 4; ++chnl) {
                ret = ibsd_sto_noisy(dd, LDOUTCTRL1(chnl), 0x04, 0xFF);
                if (ret < 0)
                        goto bail;
        }
        for (chnl = 0; chnl < 4; ++chnl) {
                ret = ibsd_sto_noisy(dd, RXHSSTATUS(chnl), 0x04, 0xFF);
                if (ret < 0)
                        goto bail;
        }
        /*
         * delay for max possible number of steps, with slop.
         * Each step is about 4usec.
         */
        udelay(415);
        for (chnl = 0; chnl < 4; ++chnl) {
                ret = ibsd_sto_noisy(dd, LDOUTCTRL1(chnl), 0x00, 0xFF);
                if (ret < 0)
                        goto bail;
        }
bail:
        return ret;
}

#define RELOCK_FIRST_MS 3
#define RXLSPPM(chan) EPB_LOC(chan, 0, 2)
void ipath_toggle_rclkrls(struct ipath_devdata *dd)
{
        int loc = RXLSPPM(0) | EPB_GLOBAL_WR;
        int ret;

        ret = ibsd_mod_allchnls(dd, loc, 0, 0x80);
        if (ret < 0)
                ipath_dev_err(dd, "RCLKRLS failed to clear D7\n");
        else {
                udelay(1);
                ibsd_mod_allchnls(dd, loc, 0x80, 0x80);
        }
        /* And again for good measure */
        udelay(1);
        ret = ibsd_mod_allchnls(dd, loc, 0, 0x80);
        if (ret < 0)
                ipath_dev_err(dd, "RCLKRLS failed to clear D7\n");
        else {
                udelay(1);
                ibsd_mod_allchnls(dd, loc, 0x80, 0x80);
        }
        /* Now reset xgxs and IBC to complete the recovery */
        dd->ipath_f_xgxs_reset(dd);
}

/*
 * Shut down the timer that polls for relock occasions, if needed
 * this is "hooked" from ipath_7220_quiet_serdes(), which is called
 * just before ipath_shutdown_device() in ipath_driver.c shuts down all
 * the other timers
 */
void ipath_shutdown_relock_poll(struct ipath_devdata *dd)
{
        struct ipath_relock *irp = &dd->ipath_relock_singleton;
        if (atomic_read(&irp->ipath_relock_timer_active)) {
                del_timer_sync(&irp->ipath_relock_timer);
                atomic_set(&irp->ipath_relock_timer_active, 0);
        }
}

static unsigned ipath_relock_by_timer = 1;
module_param_named(relock_by_timer, ipath_relock_by_timer, uint,
        S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(relock_by_timer, "Allow relock attempt if link not up");

static void ipath_run_relock(unsigned long opaque)
{
        struct ipath_devdata *dd = (struct ipath_devdata *)opaque;
        struct ipath_relock *irp = &dd->ipath_relock_singleton;
        u64 val, ltstate;

        if (!(dd->ipath_flags & IPATH_INITTED)) {
                /* Not yet up, just reenable the timer for later */
                irp->ipath_relock_interval = HZ;
                mod_timer(&irp->ipath_relock_timer, jiffies + HZ);
                return;
        }

        /*
         * Check link-training state for "stuck" state.
         * if found, try relock and schedule another try at
         * exponentially growing delay, maxed at one second.
         * if not stuck, our work is done.
         */
        val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_ibcstatus);
        ltstate = ipath_ib_linktrstate(dd, val);

        if (ltstate <= INFINIPATH_IBCS_LT_STATE_CFGWAITRMT
                && ltstate != INFINIPATH_IBCS_LT_STATE_LINKUP) {
                int timeoff;
                /* Not up yet. Try again, if allowed by module-param */
                if (ipath_relock_by_timer) {
                        if (dd->ipath_flags & IPATH_IB_AUTONEG_INPROG)
                                ipath_cdbg(VERBOSE, "Skip RELOCK in AUTONEG\n");
                        else if (!(dd->ipath_flags & IPATH_IB_LINK_DISABLED)) {
                                ipath_cdbg(VERBOSE, "RELOCK\n");
                                ipath_toggle_rclkrls(dd);
                        }
                }
                /* re-set timer for next check */
                timeoff = irp->ipath_relock_interval << 1;
                if (timeoff > HZ)
                        timeoff = HZ;
                irp->ipath_relock_interval = timeoff;

                mod_timer(&irp->ipath_relock_timer, jiffies + timeoff);
        } else {
                /* Up, so no more need to check so often */
                mod_timer(&irp->ipath_relock_timer, jiffies + HZ);
        }
}

void ipath_set_relock_poll(struct ipath_devdata *dd, int ibup)
{
        struct ipath_relock *irp = &dd->ipath_relock_singleton;

        if (ibup > 0) {
                /* we are now up, so relax timer to 1 second interval */
                if (atomic_read(&irp->ipath_relock_timer_active))
                        mod_timer(&irp->ipath_relock_timer, jiffies + HZ);
        } else {
                /* Transition to down, (re-)set timer to short interval. */
                int timeout;
                timeout = (HZ * ((ibup == -1) ? 1000 : RELOCK_FIRST_MS))/1000;
                if (timeout == 0)
                        timeout = 1;
                /* If timer has not yet been started, do so. */
                if (atomic_inc_return(&irp->ipath_relock_timer_active) == 1) {
                        init_timer(&irp->ipath_relock_timer);
                        irp->ipath_relock_timer.function = ipath_run_relock;
                        irp->ipath_relock_timer.data = (unsigned long) dd;
                        irp->ipath_relock_interval = timeout;
                        irp->ipath_relock_timer.expires = jiffies + timeout;
                        add_timer(&irp->ipath_relock_timer);
                } else {
                        irp->ipath_relock_interval = timeout;
                        mod_timer(&irp->ipath_relock_timer, jiffies + timeout);
                        atomic_dec(&irp->ipath_relock_timer_active);
                }
        }
}