IB/rdmavt, IB/qib, IB/hfi1: Use new QP put get routines

[linux/fpc-iii.git] / drivers / infiniband / hw / qib / qib_driver.c

/*
 * Copyright (c) 2013 Intel Corporation. All rights reserved.
 * Copyright (c) 2006, 2007, 2008, 2009 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.
 */

#include <linux/spinlock.h>
#include <linux/pci.h>
#include <linux/io.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/vmalloc.h>
#include <linux/module.h>
#include <linux/prefetch.h>

#include "qib.h"

/*
 * The size has to be longer than this string, so we can append
 * board/chip information to it in the init code.
 */
const char ib_qib_version[] = QIB_DRIVER_VERSION "\n";

DEFINE_SPINLOCK(qib_devs_lock);
LIST_HEAD(qib_dev_list);
DEFINE_MUTEX(qib_mutex);        /* general driver use */

unsigned qib_ibmtu;
module_param_named(ibmtu, qib_ibmtu, uint, S_IRUGO);
MODULE_PARM_DESC(ibmtu, "Set max IB MTU (0=2KB, 1=256, 2=512, ... 5=4096");

unsigned qib_compat_ddr_negotiate = 1;
module_param_named(compat_ddr_negotiate, qib_compat_ddr_negotiate, uint,
                   S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(compat_ddr_negotiate,
                 "Attempt pre-IBTA 1.2 DDR speed negotiation");

MODULE_LICENSE("Dual BSD/GPL");
MODULE_AUTHOR("Intel <ibsupport@intel.com>");
MODULE_DESCRIPTION("Intel IB driver");
MODULE_VERSION(QIB_DRIVER_VERSION);

/*
 * QIB_PIO_MAXIBHDR is the max IB header size allowed for in our
 * PIO send buffers.  This is well beyond anything currently
 * defined in the InfiniBand spec.
 */
#define QIB_PIO_MAXIBHDR 128

/*
 * QIB_MAX_PKT_RCV is the max # if packets processed per receive interrupt.
 */
#define QIB_MAX_PKT_RECV 64

struct qlogic_ib_stats qib_stats;

const char *qib_get_unit_name(int unit)
{
        static char iname[16];

        snprintf(iname, sizeof(iname), "infinipath%u", unit);
        return iname;
}

const char *qib_get_card_name(struct rvt_dev_info *rdi)
{
        struct qib_ibdev *ibdev = container_of(rdi, struct qib_ibdev, rdi);
        struct qib_devdata *dd = container_of(ibdev,
                                              struct qib_devdata, verbs_dev);
        return qib_get_unit_name(dd->unit);
}

struct pci_dev *qib_get_pci_dev(struct rvt_dev_info *rdi)
{
        struct qib_ibdev *ibdev = container_of(rdi, struct qib_ibdev, rdi);
        struct qib_devdata *dd = container_of(ibdev,
                                              struct qib_devdata, verbs_dev);
        return dd->pcidev;
}

/*
 * Return count of units with at least one port ACTIVE.
 */
int qib_count_active_units(void)
{
        struct qib_devdata *dd;
        struct qib_pportdata *ppd;
        unsigned long flags;
        int pidx, nunits_active = 0;

        spin_lock_irqsave(&qib_devs_lock, flags);
        list_for_each_entry(dd, &qib_dev_list, list) {
                if (!(dd->flags & QIB_PRESENT) || !dd->kregbase)
                        continue;
                for (pidx = 0; pidx < dd->num_pports; ++pidx) {
                        ppd = dd->pport + pidx;
                        if (ppd->lid && (ppd->lflags & (QIBL_LINKINIT |
                                         QIBL_LINKARMED | QIBL_LINKACTIVE))) {
                                nunits_active++;
                                break;
                        }
                }
        }
        spin_unlock_irqrestore(&qib_devs_lock, flags);
        return nunits_active;
}

/*
 * Return count of all units, optionally return in arguments
 * the number of usable (present) units, and the number of
 * ports that are up.
 */
int qib_count_units(int *npresentp, int *nupp)
{
        int nunits = 0, npresent = 0, nup = 0;
        struct qib_devdata *dd;
        unsigned long flags;
        int pidx;
        struct qib_pportdata *ppd;

        spin_lock_irqsave(&qib_devs_lock, flags);

        list_for_each_entry(dd, &qib_dev_list, list) {
                nunits++;
                if ((dd->flags & QIB_PRESENT) && dd->kregbase)
                        npresent++;
                for (pidx = 0; pidx < dd->num_pports; ++pidx) {
                        ppd = dd->pport + pidx;
                        if (ppd->lid && (ppd->lflags & (QIBL_LINKINIT |
                                         QIBL_LINKARMED | QIBL_LINKACTIVE)))
                                nup++;
                }
        }

        spin_unlock_irqrestore(&qib_devs_lock, flags);

        if (npresentp)
                *npresentp = npresent;
        if (nupp)
                *nupp = nup;

        return nunits;
}

/**
 * qib_wait_linkstate - wait for an IB link state change to occur
 * @dd: the qlogic_ib device
 * @state: the state to wait for
 * @msecs: the number of milliseconds to wait
 *
 * wait up to msecs milliseconds for IB link state change to occur for
 * now, take the easy polling route.  Currently used only by
 * qib_set_linkstate.  Returns 0 if state reached, otherwise
 * -ETIMEDOUT state can have multiple states set, for any of several
 * transitions.
 */
int qib_wait_linkstate(struct qib_pportdata *ppd, u32 state, int msecs)
{
        int ret;
        unsigned long flags;

        spin_lock_irqsave(&ppd->lflags_lock, flags);
        if (ppd->state_wanted) {
                spin_unlock_irqrestore(&ppd->lflags_lock, flags);
                ret = -EBUSY;
                goto bail;
        }
        ppd->state_wanted = state;
        spin_unlock_irqrestore(&ppd->lflags_lock, flags);
        wait_event_interruptible_timeout(ppd->state_wait,
                                         (ppd->lflags & state),
                                         msecs_to_jiffies(msecs));
        spin_lock_irqsave(&ppd->lflags_lock, flags);
        ppd->state_wanted = 0;
        spin_unlock_irqrestore(&ppd->lflags_lock, flags);

        if (!(ppd->lflags & state))
                ret = -ETIMEDOUT;
        else
                ret = 0;
bail:
        return ret;
}

int qib_set_linkstate(struct qib_pportdata *ppd, u8 newstate)
{
        u32 lstate;
        int ret;
        struct qib_devdata *dd = ppd->dd;
        unsigned long flags;

        switch (newstate) {
        case QIB_IB_LINKDOWN_ONLY:
                dd->f_set_ib_cfg(ppd, QIB_IB_CFG_LSTATE,
                                 IB_LINKCMD_DOWN | IB_LINKINITCMD_NOP);
                /* don't wait */
                ret = 0;
                goto bail;

        case QIB_IB_LINKDOWN:
                dd->f_set_ib_cfg(ppd, QIB_IB_CFG_LSTATE,
                                 IB_LINKCMD_DOWN | IB_LINKINITCMD_POLL);
                /* don't wait */
                ret = 0;
                goto bail;

        case QIB_IB_LINKDOWN_SLEEP:
                dd->f_set_ib_cfg(ppd, QIB_IB_CFG_LSTATE,
                                 IB_LINKCMD_DOWN | IB_LINKINITCMD_SLEEP);
                /* don't wait */
                ret = 0;
                goto bail;

        case QIB_IB_LINKDOWN_DISABLE:
                dd->f_set_ib_cfg(ppd, QIB_IB_CFG_LSTATE,
                                 IB_LINKCMD_DOWN | IB_LINKINITCMD_DISABLE);
                /* don't wait */
                ret = 0;
                goto bail;

        case QIB_IB_LINKARM:
                if (ppd->lflags & QIBL_LINKARMED) {
                        ret = 0;
                        goto bail;
                }
                if (!(ppd->lflags & (QIBL_LINKINIT | QIBL_LINKACTIVE))) {
                        ret = -EINVAL;
                        goto bail;
                }
                /*
                 * Since the port can be ACTIVE when we ask for ARMED,
                 * clear QIBL_LINKV so we can wait for a transition.
                 * If the link isn't ARMED, then something else happened
                 * and there is no point waiting for ARMED.
                 */
                spin_lock_irqsave(&ppd->lflags_lock, flags);
                ppd->lflags &= ~QIBL_LINKV;
                spin_unlock_irqrestore(&ppd->lflags_lock, flags);
                dd->f_set_ib_cfg(ppd, QIB_IB_CFG_LSTATE,
                                 IB_LINKCMD_ARMED | IB_LINKINITCMD_NOP);
                lstate = QIBL_LINKV;
                break;

        case QIB_IB_LINKACTIVE:
                if (ppd->lflags & QIBL_LINKACTIVE) {
                        ret = 0;
                        goto bail;
                }
                if (!(ppd->lflags & QIBL_LINKARMED)) {
                        ret = -EINVAL;
                        goto bail;
                }
                dd->f_set_ib_cfg(ppd, QIB_IB_CFG_LSTATE,
                                 IB_LINKCMD_ACTIVE | IB_LINKINITCMD_NOP);
                lstate = QIBL_LINKACTIVE;
                break;

        default:
                ret = -EINVAL;
                goto bail;
        }
        ret = qib_wait_linkstate(ppd, lstate, 10);

bail:
        return ret;
}

/*
 * Get address of eager buffer from it's index (allocated in chunks, not
 * contiguous).
 */
static inline void *qib_get_egrbuf(const struct qib_ctxtdata *rcd, u32 etail)
{
        const u32 chunk = etail >> rcd->rcvegrbufs_perchunk_shift;
        const u32 idx =  etail & ((u32)rcd->rcvegrbufs_perchunk - 1);

        return rcd->rcvegrbuf[chunk] + (idx << rcd->dd->rcvegrbufsize_shift);
}

/*
 * Returns 1 if error was a CRC, else 0.
 * Needed for some chip's synthesized error counters.
 */
static u32 qib_rcv_hdrerr(struct qib_ctxtdata *rcd, struct qib_pportdata *ppd,
                          u32 ctxt, u32 eflags, u32 l, u32 etail,
                          __le32 *rhf_addr, struct qib_message_header *rhdr)
{
        u32 ret = 0;

        if (eflags & (QLOGIC_IB_RHF_H_ICRCERR | QLOGIC_IB_RHF_H_VCRCERR))
                ret = 1;
        else if (eflags == QLOGIC_IB_RHF_H_TIDERR) {
                /* For TIDERR and RC QPs premptively schedule a NAK */
                struct qib_ib_header *hdr = (struct qib_ib_header *) rhdr;
                struct qib_other_headers *ohdr = NULL;
                struct qib_ibport *ibp = &ppd->ibport_data;
                struct qib_devdata *dd = ppd->dd;
                struct rvt_dev_info *rdi = &dd->verbs_dev.rdi;
                struct rvt_qp *qp = NULL;
                u32 tlen = qib_hdrget_length_in_bytes(rhf_addr);
                u16 lid  = be16_to_cpu(hdr->lrh[1]);
                int lnh = be16_to_cpu(hdr->lrh[0]) & 3;
                u32 qp_num;
                u32 opcode;
                u32 psn;
                int diff;

                /* Sanity check packet */
                if (tlen < 24)
                        goto drop;

                if (lid < be16_to_cpu(IB_MULTICAST_LID_BASE)) {
                        lid &= ~((1 << ppd->lmc) - 1);
                        if (unlikely(lid != ppd->lid))
                                goto drop;
                }

                /* Check for GRH */
                if (lnh == QIB_LRH_BTH)
                        ohdr = &hdr->u.oth;
                else if (lnh == QIB_LRH_GRH) {
                        u32 vtf;

                        ohdr = &hdr->u.l.oth;
                        if (hdr->u.l.grh.next_hdr != IB_GRH_NEXT_HDR)
                                goto drop;
                        vtf = be32_to_cpu(hdr->u.l.grh.version_tclass_flow);
                        if ((vtf >> IB_GRH_VERSION_SHIFT) != IB_GRH_VERSION)
                                goto drop;
                } else
                        goto drop;

                /* Get opcode and PSN from packet */
                opcode = be32_to_cpu(ohdr->bth[0]);
                opcode >>= 24;
                psn = be32_to_cpu(ohdr->bth[2]);

                /* Get the destination QP number. */
                qp_num = be32_to_cpu(ohdr->bth[1]) & RVT_QPN_MASK;
                if (qp_num != QIB_MULTICAST_QPN) {
                        int ruc_res;

                        rcu_read_lock();
                        qp = rvt_lookup_qpn(rdi, &ibp->rvp, qp_num);
                        if (!qp) {
                                rcu_read_unlock();
                                goto drop;
                        }

                        /*
                         * Handle only RC QPs - for other QP types drop error
                         * packet.
                         */
                        spin_lock(&qp->r_lock);

                        /* Check for valid receive state. */
                        if (!(ib_rvt_state_ops[qp->state] &
                              RVT_PROCESS_RECV_OK)) {
                                ibp->rvp.n_pkt_drops++;
                                goto unlock;
                        }

                        switch (qp->ibqp.qp_type) {
                        case IB_QPT_RC:
                                ruc_res =
                                        qib_ruc_check_hdr(
                                                ibp, hdr,
                                                lnh == QIB_LRH_GRH,
                                                qp,
                                                be32_to_cpu(ohdr->bth[0]));
                                if (ruc_res)
                                        goto unlock;

                                /* Only deal with RDMA Writes for now */
                                if (opcode <
                                    IB_OPCODE_RC_RDMA_READ_RESPONSE_FIRST) {
                                        diff = qib_cmp24(psn, qp->r_psn);
                                        if (!qp->r_nak_state && diff >= 0) {
                                                ibp->rvp.n_rc_seqnak++;
                                                qp->r_nak_state =
                                                        IB_NAK_PSN_ERROR;
                                                /* Use the expected PSN. */
                                                qp->r_ack_psn = qp->r_psn;
                                                /*
                                                 * Wait to send the sequence
                                                 * NAK until all packets
                                                 * in the receive queue have
                                                 * been processed.
                                                 * Otherwise, we end up
                                                 * propagating congestion.
                                                 */
                                                if (list_empty(&qp->rspwait)) {
                                                        qp->r_flags |=
                                                                RVT_R_RSP_NAK;
                                                        atomic_inc(
                                                                &qp->refcount);
                                                        list_add_tail(
                                                         &qp->rspwait,
                                                         &rcd->qp_wait_list);
                                                }
                                        } /* Out of sequence NAK */
                                } /* QP Request NAKs */
                                break;
                        case IB_QPT_SMI:
                        case IB_QPT_GSI:
                        case IB_QPT_UD:
                        case IB_QPT_UC:
                        default:
                                /* For now don't handle any other QP types */
                                break;
                        }

unlock:
                        spin_unlock(&qp->r_lock);
                        rcu_read_unlock();
                } /* Unicast QP */
        } /* Valid packet with TIDErr */

drop:
        return ret;
}

/*
 * qib_kreceive - receive a packet
 * @rcd: the qlogic_ib context
 * @llic: gets count of good packets needed to clear lli,
 *          (used with chips that need need to track crcs for lli)
 *
 * called from interrupt handler for errors or receive interrupt
 * Returns number of CRC error packets, needed by some chips for
 * local link integrity tracking.   crcs are adjusted down by following
 * good packets, if any, and count of good packets is also tracked.
 */
u32 qib_kreceive(struct qib_ctxtdata *rcd, u32 *llic, u32 *npkts)
{
        struct qib_devdata *dd = rcd->dd;
        struct qib_pportdata *ppd = rcd->ppd;
        __le32 *rhf_addr;
        void *ebuf;
        const u32 rsize = dd->rcvhdrentsize;        /* words */
        const u32 maxcnt = dd->rcvhdrcnt * rsize;   /* words */
        u32 etail = -1, l, hdrqtail;
        struct qib_message_header *hdr;
        u32 eflags, etype, tlen, i = 0, updegr = 0, crcs = 0;
        int last;
        u64 lval;
        struct rvt_qp *qp, *nqp;

        l = rcd->head;
        rhf_addr = (__le32 *) rcd->rcvhdrq + l + dd->rhf_offset;
        if (dd->flags & QIB_NODMA_RTAIL) {
                u32 seq = qib_hdrget_seq(rhf_addr);

                if (seq != rcd->seq_cnt)
                        goto bail;
                hdrqtail = 0;
        } else {
                hdrqtail = qib_get_rcvhdrtail(rcd);
                if (l == hdrqtail)
                        goto bail;
                smp_rmb();  /* prevent speculative reads of dma'ed hdrq */
        }

        for (last = 0, i = 1; !last; i += !last) {
                hdr = dd->f_get_msgheader(dd, rhf_addr);
                eflags = qib_hdrget_err_flags(rhf_addr);
                etype = qib_hdrget_rcv_type(rhf_addr);
                /* total length */
                tlen = qib_hdrget_length_in_bytes(rhf_addr);
                ebuf = NULL;
                if ((dd->flags & QIB_NODMA_RTAIL) ?
                    qib_hdrget_use_egr_buf(rhf_addr) :
                    (etype != RCVHQ_RCV_TYPE_EXPECTED)) {
                        etail = qib_hdrget_index(rhf_addr);
                        updegr = 1;
                        if (tlen > sizeof(*hdr) ||
                            etype >= RCVHQ_RCV_TYPE_NON_KD) {
                                ebuf = qib_get_egrbuf(rcd, etail);
                                prefetch_range(ebuf, tlen - sizeof(*hdr));
                        }
                }
                if (!eflags) {
                        u16 lrh_len = be16_to_cpu(hdr->lrh[2]) << 2;

                        if (lrh_len != tlen) {
                                qib_stats.sps_lenerrs++;
                                goto move_along;
                        }
                }
                if (etype == RCVHQ_RCV_TYPE_NON_KD && !eflags &&
                    ebuf == NULL &&
                    tlen > (dd->rcvhdrentsize - 2 + 1 -
                                qib_hdrget_offset(rhf_addr)) << 2) {
                        goto move_along;
                }

                /*
                 * Both tiderr and qibhdrerr are set for all plain IB
                 * packets; only qibhdrerr should be set.
                 */
                if (unlikely(eflags))
                        crcs += qib_rcv_hdrerr(rcd, ppd, rcd->ctxt, eflags, l,
                                               etail, rhf_addr, hdr);
                else if (etype == RCVHQ_RCV_TYPE_NON_KD) {
                        qib_ib_rcv(rcd, hdr, ebuf, tlen);
                        if (crcs)
                                crcs--;
                        else if (llic && *llic)
                                --*llic;
                }
move_along:
                l += rsize;
                if (l >= maxcnt)
                        l = 0;
                if (i == QIB_MAX_PKT_RECV)
                        last = 1;

                rhf_addr = (__le32 *) rcd->rcvhdrq + l + dd->rhf_offset;
                if (dd->flags & QIB_NODMA_RTAIL) {
                        u32 seq = qib_hdrget_seq(rhf_addr);

                        if (++rcd->seq_cnt > 13)
                                rcd->seq_cnt = 1;
                        if (seq != rcd->seq_cnt)
                                last = 1;
                } else if (l == hdrqtail)
                        last = 1;
                /*
                 * Update head regs etc., every 16 packets, if not last pkt,
                 * to help prevent rcvhdrq overflows, when many packets
                 * are processed and queue is nearly full.
                 * Don't request an interrupt for intermediate updates.
                 */
                lval = l;
                if (!last && !(i & 0xf)) {
                        dd->f_update_usrhead(rcd, lval, updegr, etail, i);
                        updegr = 0;
                }
        }

        rcd->head = l;

        /*
         * Iterate over all QPs waiting to respond.
         * The list won't change since the IRQ is only run on one CPU.
         */
        list_for_each_entry_safe(qp, nqp, &rcd->qp_wait_list, rspwait) {
                list_del_init(&qp->rspwait);
                if (qp->r_flags & RVT_R_RSP_NAK) {
                        qp->r_flags &= ~RVT_R_RSP_NAK;
                        qib_send_rc_ack(qp);
                }
                if (qp->r_flags & RVT_R_RSP_SEND) {
                        unsigned long flags;

                        qp->r_flags &= ~RVT_R_RSP_SEND;
                        spin_lock_irqsave(&qp->s_lock, flags);
                        if (ib_rvt_state_ops[qp->state] &
                                        RVT_PROCESS_OR_FLUSH_SEND)
                                qib_schedule_send(qp);
                        spin_unlock_irqrestore(&qp->s_lock, flags);
                }
                rvt_put_qp(qp);
        }

bail:
        /* Report number of packets consumed */
        if (npkts)
                *npkts = i;

        /*
         * Always write head at end, and setup rcv interrupt, even
         * if no packets were processed.
         */
        lval = (u64)rcd->head | dd->rhdrhead_intr_off;
        dd->f_update_usrhead(rcd, lval, updegr, etail, i);
        return crcs;
}

/**
 * qib_set_mtu - set the MTU
 * @ppd: the perport data
 * @arg: the new MTU
 *
 * We can handle "any" incoming size, the issue here is whether we
 * need to restrict our outgoing size.   For now, we don't do any
 * sanity checking on this, and we don't deal with what happens to
 * programs that are already running when the size changes.
 * NOTE: changing the MTU will usually cause the IBC to go back to
 * link INIT state...
 */
int qib_set_mtu(struct qib_pportdata *ppd, u16 arg)
{
        u32 piosize;
        int ret, chk;

        if (arg != 256 && arg != 512 && arg != 1024 && arg != 2048 &&
            arg != 4096) {
                ret = -EINVAL;
                goto bail;
        }
        chk = ib_mtu_enum_to_int(qib_ibmtu);
        if (chk > 0 && arg > chk) {
                ret = -EINVAL;
                goto bail;
        }

        piosize = ppd->ibmaxlen;
        ppd->ibmtu = arg;

        if (arg >= (piosize - QIB_PIO_MAXIBHDR)) {
                /* Only if it's not the initial value (or reset to it) */
                if (piosize != ppd->init_ibmaxlen) {
                        if (arg > piosize && arg <= ppd->init_ibmaxlen)
                                piosize = ppd->init_ibmaxlen - 2 * sizeof(u32);
                        ppd->ibmaxlen = piosize;
                }
        } else if ((arg + QIB_PIO_MAXIBHDR) != ppd->ibmaxlen) {
                piosize = arg + QIB_PIO_MAXIBHDR - 2 * sizeof(u32);
                ppd->ibmaxlen = piosize;
        }

        ppd->dd->f_set_ib_cfg(ppd, QIB_IB_CFG_MTU, 0);

        ret = 0;

bail:
        return ret;
}

int qib_set_lid(struct qib_pportdata *ppd, u32 lid, u8 lmc)
{
        struct qib_devdata *dd = ppd->dd;

        ppd->lid = lid;
        ppd->lmc = lmc;

        dd->f_set_ib_cfg(ppd, QIB_IB_CFG_LIDLMC,
                         lid | (~((1U << lmc) - 1)) << 16);

        qib_devinfo(dd->pcidev, "IB%u:%u got a lid: 0x%x\n",
                    dd->unit, ppd->port, lid);

        return 0;
}

/*
 * Following deal with the "obviously simple" task of overriding the state
 * of the LEDS, which normally indicate link physical and logical status.
 * The complications arise in dealing with different hardware mappings
 * and the board-dependent routine being called from interrupts.
 * and then there's the requirement to _flash_ them.
 */
#define LED_OVER_FREQ_SHIFT 8
#define LED_OVER_FREQ_MASK (0xFF<<LED_OVER_FREQ_SHIFT)
/* Below is "non-zero" to force override, but both actual LEDs are off */
#define LED_OVER_BOTH_OFF (8)

static void qib_run_led_override(unsigned long opaque)
{
        struct qib_pportdata *ppd = (struct qib_pportdata *)opaque;
        struct qib_devdata *dd = ppd->dd;
        int timeoff;
        int ph_idx;

        if (!(dd->flags & QIB_INITTED))
                return;

        ph_idx = ppd->led_override_phase++ & 1;
        ppd->led_override = ppd->led_override_vals[ph_idx];
        timeoff = ppd->led_override_timeoff;

        dd->f_setextled(ppd, 1);
        /*
         * don't re-fire the timer if user asked for it to be off; we let
         * it fire one more time after they turn it off to simplify
         */
        if (ppd->led_override_vals[0] || ppd->led_override_vals[1])
                mod_timer(&ppd->led_override_timer, jiffies + timeoff);
}

void qib_set_led_override(struct qib_pportdata *ppd, unsigned int val)
{
        struct qib_devdata *dd = ppd->dd;
        int timeoff, freq;

        if (!(dd->flags & QIB_INITTED))
                return;

        /* First check if we are blinking. If not, use 1HZ polling */
        timeoff = HZ;
        freq = (val & LED_OVER_FREQ_MASK) >> LED_OVER_FREQ_SHIFT;

        if (freq) {
                /* For blink, set each phase from one nybble of val */
                ppd->led_override_vals[0] = val & 0xF;
                ppd->led_override_vals[1] = (val >> 4) & 0xF;
                timeoff = (HZ << 4)/freq;
        } else {
                /* Non-blink set both phases the same. */
                ppd->led_override_vals[0] = val & 0xF;
                ppd->led_override_vals[1] = val & 0xF;
        }
        ppd->led_override_timeoff = timeoff;

        /*
         * If the timer has not already been started, do so. Use a "quick"
         * timeout so the function will be called soon, to look at our request.
         */
        if (atomic_inc_return(&ppd->led_override_timer_active) == 1) {
                /* Need to start timer */
                init_timer(&ppd->led_override_timer);
                ppd->led_override_timer.function = qib_run_led_override;
                ppd->led_override_timer.data = (unsigned long) ppd;
                ppd->led_override_timer.expires = jiffies + 1;
                add_timer(&ppd->led_override_timer);
        } else {
                if (ppd->led_override_vals[0] || ppd->led_override_vals[1])
                        mod_timer(&ppd->led_override_timer, jiffies + 1);
                atomic_dec(&ppd->led_override_timer_active);
        }
}

/**
 * qib_reset_device - reset the chip if possible
 * @unit: the device to reset
 *
 * Whether or not reset is successful, we attempt to re-initialize the chip
 * (that is, much like a driver unload/reload).  We clear the INITTED flag
 * so that the various entry points will fail until we reinitialize.  For
 * now, we only allow this if no user contexts are open that use chip resources
 */
int qib_reset_device(int unit)
{
        int ret, i;
        struct qib_devdata *dd = qib_lookup(unit);
        struct qib_pportdata *ppd;
        unsigned long flags;
        int pidx;

        if (!dd) {
                ret = -ENODEV;
                goto bail;
        }

        qib_devinfo(dd->pcidev, "Reset on unit %u requested\n", unit);

        if (!dd->kregbase || !(dd->flags & QIB_PRESENT)) {
                qib_devinfo(dd->pcidev,
                        "Invalid unit number %u or not initialized or not present\n",
                        unit);
                ret = -ENXIO;
                goto bail;
        }

        spin_lock_irqsave(&dd->uctxt_lock, flags);
        if (dd->rcd)
                for (i = dd->first_user_ctxt; i < dd->cfgctxts; i++) {
                        if (!dd->rcd[i] || !dd->rcd[i]->cnt)
                                continue;
                        spin_unlock_irqrestore(&dd->uctxt_lock, flags);
                        ret = -EBUSY;
                        goto bail;
                }
        spin_unlock_irqrestore(&dd->uctxt_lock, flags);

        for (pidx = 0; pidx < dd->num_pports; ++pidx) {
                ppd = dd->pport + pidx;
                if (atomic_read(&ppd->led_override_timer_active)) {
                        /* Need to stop LED timer, _then_ shut off LEDs */
                        del_timer_sync(&ppd->led_override_timer);
                        atomic_set(&ppd->led_override_timer_active, 0);
                }

                /* Shut off LEDs after we are sure timer is not running */
                ppd->led_override = LED_OVER_BOTH_OFF;
                dd->f_setextled(ppd, 0);
                if (dd->flags & QIB_HAS_SEND_DMA)
                        qib_teardown_sdma(ppd);
        }

        ret = dd->f_reset(dd);
        if (ret == 1)
                ret = qib_init(dd, 1);
        else
                ret = -EAGAIN;
        if (ret)
                qib_dev_err(dd,
                        "Reinitialize unit %u after reset failed with %d\n",
                        unit, ret);
        else
                qib_devinfo(dd->pcidev,
                        "Reinitialized unit %u after resetting\n",
                        unit);

bail:
        return ret;
}