Merge rsync://rsync.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

[deliverable/linux.git] / drivers / infiniband / hw / ipath / ipath_driver.c

/*
 * 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/idr.h>
#include <linux/pci.h>
#include <linux/delay.h>
#include <linux/netdevice.h>
#include <linux/vmalloc.h>

#include "ipath_kernel.h"
#include "ips_common.h"
#include "ipath_layer.h"

static void ipath_update_pio_bufs(struct ipath_devdata *);

const char *ipath_get_unit_name(int unit)
{
        static char iname[16];
        snprintf(iname, sizeof iname, "infinipath%u", unit);
        return iname;
}

EXPORT_SYMBOL_GPL(ipath_get_unit_name);

#define DRIVER_LOAD_MSG "PathScale " IPATH_DRV_NAME " loaded: "
#define PFX IPATH_DRV_NAME ": "

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

static struct idr unit_table;
DEFINE_SPINLOCK(ipath_devs_lock);
LIST_HEAD(ipath_dev_list);

wait_queue_head_t ipath_sma_state_wait;

unsigned ipath_debug = __IPATH_INFO;

module_param_named(debug, ipath_debug, uint, S_IWUSR | S_IRUGO);
MODULE_PARM_DESC(debug, "mask for debug prints");
EXPORT_SYMBOL_GPL(ipath_debug);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("PathScale <support@pathscale.com>");
MODULE_DESCRIPTION("Pathscale InfiniPath driver");

const char *ipath_ibcstatus_str[] = {
        "Disabled",
        "LinkUp",
        "PollActive",
        "PollQuiet",
        "SleepDelay",
        "SleepQuiet",
        "LState6",              /* unused */
        "LState7",              /* unused */
        "CfgDebounce",
        "CfgRcvfCfg",
        "CfgWaitRmt",
        "CfgIdle",
        "RecovRetrain",
        "LState0xD",            /* unused */
        "RecovWaitRmt",
        "RecovIdle",
};

/*
 * These variables are initialized in the chip-specific files
 * but are defined here.
 */
u16 ipath_gpio_sda_num, ipath_gpio_scl_num;
u64 ipath_gpio_sda, ipath_gpio_scl;
u64 infinipath_i_bitsextant;
ipath_err_t infinipath_e_bitsextant, infinipath_hwe_bitsextant;
u32 infinipath_i_rcvavail_mask, infinipath_i_rcvurg_mask;

static void __devexit ipath_remove_one(struct pci_dev *);
static int __devinit ipath_init_one(struct pci_dev *,
                                    const struct pci_device_id *);

/* Only needed for registration, nothing else needs this info */
#define PCI_VENDOR_ID_PATHSCALE 0x1fc1
#define PCI_DEVICE_ID_INFINIPATH_HT 0xd
#define PCI_DEVICE_ID_INFINIPATH_PE800 0x10

static const struct pci_device_id ipath_pci_tbl[] = {
        {PCI_DEVICE(PCI_VENDOR_ID_PATHSCALE,
                    PCI_DEVICE_ID_INFINIPATH_HT)},
        {PCI_DEVICE(PCI_VENDOR_ID_PATHSCALE,
                    PCI_DEVICE_ID_INFINIPATH_PE800)},
};

MODULE_DEVICE_TABLE(pci, ipath_pci_tbl);

static struct pci_driver ipath_driver = {
        .name = IPATH_DRV_NAME,
        .probe = ipath_init_one,
        .remove = __devexit_p(ipath_remove_one),
        .id_table = ipath_pci_tbl,
};

/*
 * This is where port 0's rcvhdrtail register is written back; we also
 * want nothing else sharing the cache line, so make it a cache line
 * in size.  Used for all units.
 */
volatile __le64 *ipath_port0_rcvhdrtail;
dma_addr_t ipath_port0_rcvhdrtail_dma;
static int port0_rcvhdrtail_refs;

static inline void read_bars(struct ipath_devdata *dd, struct pci_dev *dev,
                             u32 *bar0, u32 *bar1)
{
        int ret;

        ret = pci_read_config_dword(dev, PCI_BASE_ADDRESS_0, bar0);
        if (ret)
                ipath_dev_err(dd, "failed to read bar0 before enable: "
                              "error %d\n", -ret);

        ret = pci_read_config_dword(dev, PCI_BASE_ADDRESS_1, bar1);
        if (ret)
                ipath_dev_err(dd, "failed to read bar1 before enable: "
                              "error %d\n", -ret);

        ipath_dbg("Read bar0 %x bar1 %x\n", *bar0, *bar1);
}

static void ipath_free_devdata(struct pci_dev *pdev,
                               struct ipath_devdata *dd)
{
        unsigned long flags;

        pci_set_drvdata(pdev, NULL);

        if (dd->ipath_unit != -1) {
                spin_lock_irqsave(&ipath_devs_lock, flags);
                idr_remove(&unit_table, dd->ipath_unit);
                list_del(&dd->ipath_list);
                spin_unlock_irqrestore(&ipath_devs_lock, flags);
        }
        dma_free_coherent(&pdev->dev, sizeof(*dd), dd, dd->ipath_dma_addr);
}

static struct ipath_devdata *ipath_alloc_devdata(struct pci_dev *pdev)
{
        unsigned long flags;
        struct ipath_devdata *dd;
        dma_addr_t dma_addr;
        int ret;

        if (!idr_pre_get(&unit_table, GFP_KERNEL)) {
                dd = ERR_PTR(-ENOMEM);
                goto bail;
        }

        dd = dma_alloc_coherent(&pdev->dev, sizeof(*dd), &dma_addr,
                                GFP_KERNEL);

        if (!dd) {
                dd = ERR_PTR(-ENOMEM);
                goto bail;
        }

        dd->ipath_dma_addr = dma_addr;
        dd->ipath_unit = -1;

        spin_lock_irqsave(&ipath_devs_lock, flags);

        ret = idr_get_new(&unit_table, dd, &dd->ipath_unit);
        if (ret < 0) {
                printk(KERN_ERR IPATH_DRV_NAME
                       ": Could not allocate unit ID: error %d\n", -ret);
                ipath_free_devdata(pdev, dd);
                dd = ERR_PTR(ret);
                goto bail_unlock;
        }

        dd->pcidev = pdev;
        pci_set_drvdata(pdev, dd);

        list_add(&dd->ipath_list, &ipath_dev_list);

bail_unlock:
        spin_unlock_irqrestore(&ipath_devs_lock, flags);

bail:
        return dd;
}

static inline struct ipath_devdata *__ipath_lookup(int unit)
{
        return idr_find(&unit_table, unit);
}

struct ipath_devdata *ipath_lookup(int unit)
{
        struct ipath_devdata *dd;
        unsigned long flags;

        spin_lock_irqsave(&ipath_devs_lock, flags);
        dd = __ipath_lookup(unit);
        spin_unlock_irqrestore(&ipath_devs_lock, flags);

        return dd;
}

int ipath_count_units(int *npresentp, int *nupp, u32 *maxportsp)
{
        int nunits, npresent, nup;
        struct ipath_devdata *dd;
        unsigned long flags;
        u32 maxports;

        nunits = npresent = nup = maxports = 0;

        spin_lock_irqsave(&ipath_devs_lock, flags);

        list_for_each_entry(dd, &ipath_dev_list, ipath_list) {
                nunits++;
                if ((dd->ipath_flags & IPATH_PRESENT) && dd->ipath_kregbase)
                        npresent++;
                if (dd->ipath_lid &&
                    !(dd->ipath_flags & (IPATH_DISABLED | IPATH_LINKDOWN
                                         | IPATH_LINKUNK)))
                        nup++;
                if (dd->ipath_cfgports > maxports)
                        maxports = dd->ipath_cfgports;
        }

        spin_unlock_irqrestore(&ipath_devs_lock, flags);

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

        return nunits;
}

static int init_port0_rcvhdrtail(struct pci_dev *pdev)
{
        int ret;

        mutex_lock(&ipath_mutex);

        if (!ipath_port0_rcvhdrtail) {
                ipath_port0_rcvhdrtail =
                        dma_alloc_coherent(&pdev->dev,
                                           IPATH_PORT0_RCVHDRTAIL_SIZE,
                                           &ipath_port0_rcvhdrtail_dma,
                                           GFP_KERNEL);

                if (!ipath_port0_rcvhdrtail) {
                        ret = -ENOMEM;
                        goto bail;
                }
        }
        port0_rcvhdrtail_refs++;
        ret = 0;

bail:
        mutex_unlock(&ipath_mutex);

        return ret;
}

static void cleanup_port0_rcvhdrtail(struct pci_dev *pdev)
{
        mutex_lock(&ipath_mutex);

        if (!--port0_rcvhdrtail_refs) {
                dma_free_coherent(&pdev->dev, IPATH_PORT0_RCVHDRTAIL_SIZE,
                                  (void *) ipath_port0_rcvhdrtail,
                                  ipath_port0_rcvhdrtail_dma);
                ipath_port0_rcvhdrtail = NULL;
        }

        mutex_unlock(&ipath_mutex);
}

/*
 * These next two routines are placeholders in case we don't have per-arch
 * code for controlling write combining.  If explicit control of write
 * combining is not available, performance will probably be awful.
 */

int __attribute__((weak)) ipath_enable_wc(struct ipath_devdata *dd)
{
        return -EOPNOTSUPP;
}

void __attribute__((weak)) ipath_disable_wc(struct ipath_devdata *dd)
{
}

static int __devinit ipath_init_one(struct pci_dev *pdev,
                                    const struct pci_device_id *ent)
{
        int ret, len, j;
        struct ipath_devdata *dd;
        unsigned long long addr;
        u32 bar0 = 0, bar1 = 0;
        u8 rev;

        ret = init_port0_rcvhdrtail(pdev);
        if (ret < 0) {
                printk(KERN_ERR IPATH_DRV_NAME
                       ": Could not allocate port0_rcvhdrtail: error %d\n",
                       -ret);
                goto bail;
        }

        dd = ipath_alloc_devdata(pdev);
        if (IS_ERR(dd)) {
                ret = PTR_ERR(dd);
                printk(KERN_ERR IPATH_DRV_NAME
                       ": Could not allocate devdata: error %d\n", -ret);
                goto bail_rcvhdrtail;
        }

        ipath_cdbg(VERBOSE, "initializing unit #%u\n", dd->ipath_unit);

        read_bars(dd, pdev, &bar0, &bar1);

        ret = pci_enable_device(pdev);
        if (ret) {
                /* This can happen iff:
                 *
                 * We did a chip reset, and then failed to reprogram the
                 * BAR, or the chip reset due to an internal error.  We then
                 * unloaded the driver and reloaded it.
                 *
                 * Both reset cases set the BAR back to initial state.  For
                 * the latter case, the AER sticky error bit at offset 0x718
                 * should be set, but the Linux kernel doesn't yet know
                 * about that, it appears.  If the original BAR was retained
                 * in the kernel data structures, this may be OK.
                 */
                ipath_dev_err(dd, "enable unit %d failed: error %d\n",
                              dd->ipath_unit, -ret);
                goto bail_devdata;
        }
        addr = pci_resource_start(pdev, 0);
        len = pci_resource_len(pdev, 0);
        ipath_cdbg(VERBOSE, "regbase (0) %llx len %d irq %x, vend %x/%x "
                   "driver_data %lx\n", addr, len, pdev->irq, ent->vendor,
                   ent->device, ent->driver_data);

        read_bars(dd, pdev, &bar0, &bar1);

        if (!bar1 && !(bar0 & ~0xf)) {
                if (addr) {
                        dev_info(&pdev->dev, "BAR is 0 (probable RESET), "
                                 "rewriting as %llx\n", addr);
                        ret = pci_write_config_dword(
                                pdev, PCI_BASE_ADDRESS_0, addr);
                        if (ret) {
                                ipath_dev_err(dd, "rewrite of BAR0 "
                                              "failed: err %d\n", -ret);
                                goto bail_disable;
                        }
                        ret = pci_write_config_dword(
                                pdev, PCI_BASE_ADDRESS_1, addr >> 32);
                        if (ret) {
                                ipath_dev_err(dd, "rewrite of BAR1 "
                                              "failed: err %d\n", -ret);
                                goto bail_disable;
                        }
                } else {
                        ipath_dev_err(dd, "BAR is 0 (probable RESET), "
                                      "not usable until reboot\n");
                        ret = -ENODEV;
                        goto bail_disable;
                }
        }

        ret = pci_request_regions(pdev, IPATH_DRV_NAME);
        if (ret) {
                dev_info(&pdev->dev, "pci_request_regions unit %u fails: "
                         "err %d\n", dd->ipath_unit, -ret);
                goto bail_disable;
        }

        ret = pci_set_dma_mask(pdev, DMA_64BIT_MASK);
        if (ret) {
                dev_info(&pdev->dev, "pci_set_dma_mask unit %u "
                         "fails: %d\n", dd->ipath_unit, ret);
                goto bail_regions;
        }

        pci_set_master(pdev);

        /*
         * Save BARs to rewrite after device reset.  Save all 64 bits of
         * BAR, just in case.
         */
        dd->ipath_pcibar0 = addr;
        dd->ipath_pcibar1 = addr >> 32;
        dd->ipath_deviceid = ent->device;       /* save for later use */
        dd->ipath_vendorid = ent->vendor;

        /* setup the chip-specific functions, as early as possible. */
        switch (ent->device) {
        case PCI_DEVICE_ID_INFINIPATH_HT:
                ipath_init_ht400_funcs(dd);
                break;
        case PCI_DEVICE_ID_INFINIPATH_PE800:
                ipath_init_pe800_funcs(dd);
                break;
        default:
                ipath_dev_err(dd, "Found unknown PathScale deviceid 0x%x, "
                              "failing\n", ent->device);
                return -ENODEV;
        }

        for (j = 0; j < 6; j++) {
                if (!pdev->resource[j].start)
                        continue;
                ipath_cdbg(VERBOSE, "BAR %d start %lx, end %lx, len %lx\n",
                           j, pdev->resource[j].start,
                           pdev->resource[j].end,
                           pci_resource_len(pdev, j));
        }

        if (!addr) {
                ipath_dev_err(dd, "No valid address in BAR 0!\n");
                ret = -ENODEV;
                goto bail_regions;
        }

        dd->ipath_deviceid = ent->device;       /* save for later use */
        dd->ipath_vendorid = ent->vendor;

        ret = pci_read_config_byte(pdev, PCI_REVISION_ID, &rev);
        if (ret) {
                ipath_dev_err(dd, "Failed to read PCI revision ID unit "
                              "%u: err %d\n", dd->ipath_unit, -ret);
                goto bail_regions;      /* shouldn't ever happen */
        }
        dd->ipath_pcirev = rev;

        dd->ipath_kregbase = ioremap_nocache(addr, len);

        if (!dd->ipath_kregbase) {
                ipath_dbg("Unable to map io addr %llx to kvirt, failing\n",
                          addr);
                ret = -ENOMEM;
                goto bail_iounmap;
        }
        dd->ipath_kregend = (u64 __iomem *)
                ((void __iomem *)dd->ipath_kregbase + len);
        dd->ipath_physaddr = addr;      /* used for io_remap, etc. */
        /* for user mmap */
        dd->ipath_kregvirt = (u64 __iomem *) phys_to_virt(addr);
        ipath_cdbg(VERBOSE, "mapped io addr %llx to kregbase %p "
                   "kregvirt %p\n", addr, dd->ipath_kregbase,
                   dd->ipath_kregvirt);

        /*
         * clear ipath_flags here instead of in ipath_init_chip as it is set
         * by ipath_setup_htconfig.
         */
        dd->ipath_flags = 0;

        if (dd->ipath_f_bus(dd, pdev))
                ipath_dev_err(dd, "Failed to setup config space; "
                              "continuing anyway\n");

        /*
         * set up our interrupt handler; SA_SHIRQ probably not needed,
         * since MSI interrupts shouldn't be shared but won't  hurt for now.
         * check 0 irq after we return from chip-specific bus setup, since
         * that can affect this due to setup
         */
        if (!pdev->irq)
                ipath_dev_err(dd, "irq is 0, BIOS error?  Interrupts won't "
                              "work\n");
        else {
                ret = request_irq(pdev->irq, ipath_intr, SA_SHIRQ,
                                  IPATH_DRV_NAME, dd);
                if (ret) {
                        ipath_dev_err(dd, "Couldn't setup irq handler, "
                                      "irq=%u: %d\n", pdev->irq, ret);
                        goto bail_iounmap;
                }
        }

        ret = ipath_init_chip(dd, 0);   /* do the chip-specific init */
        if (ret)
                goto bail_iounmap;

        ret = ipath_enable_wc(dd);

        if (ret) {
                ipath_dev_err(dd, "Write combining not enabled "
                              "(err %d): performance may be poor\n",
                              -ret);
                ret = 0;
        }

        ipath_device_create_group(&pdev->dev, dd);
        ipathfs_add_device(dd);
        ipath_user_add(dd);
        ipath_layer_add(dd);

        goto bail;

bail_iounmap:
        iounmap((volatile void __iomem *) dd->ipath_kregbase);

bail_regions:
        pci_release_regions(pdev);

bail_disable:
        pci_disable_device(pdev);

bail_devdata:
        ipath_free_devdata(pdev, dd);

bail_rcvhdrtail:
        cleanup_port0_rcvhdrtail(pdev);

bail:
        return ret;
}

static void __devexit ipath_remove_one(struct pci_dev *pdev)
{
        struct ipath_devdata *dd;

        ipath_cdbg(VERBOSE, "removing, pdev=%p\n", pdev);
        if (!pdev)
                return;

        dd = pci_get_drvdata(pdev);
        ipath_layer_del(dd);
        ipath_user_del(dd);
        ipathfs_remove_device(dd);
        ipath_device_remove_group(&pdev->dev, dd);
        ipath_cdbg(VERBOSE, "Releasing pci memory regions, dd %p, "
                   "unit %u\n", dd, (u32) dd->ipath_unit);
        if (dd->ipath_kregbase) {
                ipath_cdbg(VERBOSE, "Unmapping kregbase %p\n",
                           dd->ipath_kregbase);
                iounmap((volatile void __iomem *) dd->ipath_kregbase);
                dd->ipath_kregbase = NULL;
        }
        pci_release_regions(pdev);
        ipath_cdbg(VERBOSE, "calling pci_disable_device\n");
        pci_disable_device(pdev);

        ipath_free_devdata(pdev, dd);
        cleanup_port0_rcvhdrtail(pdev);
}

/* general driver use */
DEFINE_MUTEX(ipath_mutex);

static DEFINE_SPINLOCK(ipath_pioavail_lock);

/**
 * ipath_disarm_piobufs - cancel a range of PIO buffers
 * @dd: the infinipath device
 * @first: the first PIO buffer to cancel
 * @cnt: the number of PIO buffers to cancel
 *
 * cancel a range of PIO buffers, used when they might be armed, but
 * not triggered.  Used at init to ensure buffer state, and also user
 * process close, in case it died while writing to a PIO buffer
 * Also after errors.
 */
void ipath_disarm_piobufs(struct ipath_devdata *dd, unsigned first,
                          unsigned cnt)
{
        unsigned i, last = first + cnt;
        u64 sendctrl, sendorig;

        ipath_cdbg(PKT, "disarm %u PIObufs first=%u\n", cnt, first);
        sendorig = dd->ipath_sendctrl | INFINIPATH_S_DISARM;
        for (i = first; i < last; i++) {
                sendctrl = sendorig |
                        (i << INFINIPATH_S_DISARMPIOBUF_SHIFT);
                ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
                                 sendctrl);
        }

        /*
         * Write it again with current value, in case ipath_sendctrl changed
         * while we were looping; no critical bits that would require
         * locking.
         *
         * Write a 0, and then the original value, reading scratch in
         * between.  This seems to avoid a chip timing race that causes
         * pioavail updates to memory to stop.
         */
        ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
                         0);
        sendorig = ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
        ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
                         dd->ipath_sendctrl);
}

/**
 * ipath_wait_linkstate - wait for an IB link state change to occur
 * @dd: the infinipath 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
 * ipath_layer_set_linkstate.  Returns 0 if state reached, otherwise
 * -ETIMEDOUT state can have multiple states set, for any of several
 * transitions.
 */
int ipath_wait_linkstate(struct ipath_devdata *dd, u32 state, int msecs)
{
        dd->ipath_sma_state_wanted = state;
        wait_event_interruptible_timeout(ipath_sma_state_wait,
                                         (dd->ipath_flags & state),
                                         msecs_to_jiffies(msecs));
        dd->ipath_sma_state_wanted = 0;

        if (!(dd->ipath_flags & state)) {
                u64 val;
                ipath_cdbg(SMA, "Didn't reach linkstate %s within %u ms\n",
                           /* test INIT ahead of DOWN, both can be set */
                           (state & IPATH_LINKINIT) ? "INIT" :
                           ((state & IPATH_LINKDOWN) ? "DOWN" :
                            ((state & IPATH_LINKARMED) ? "ARM" : "ACTIVE")),
                           msecs);
                val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_ibcstatus);
                ipath_cdbg(VERBOSE, "ibcc=%llx ibcstatus=%llx (%s)\n",
                           (unsigned long long) ipath_read_kreg64(
                                   dd, dd->ipath_kregs->kr_ibcctrl),
                           (unsigned long long) val,
                           ipath_ibcstatus_str[val & 0xf]);
        }
        return (dd->ipath_flags & state) ? 0 : -ETIMEDOUT;
}

void ipath_decode_err(char *buf, size_t blen, ipath_err_t err)
{
        *buf = '\0';
        if (err & INFINIPATH_E_RHDRLEN)
                strlcat(buf, "rhdrlen ", blen);
        if (err & INFINIPATH_E_RBADTID)
                strlcat(buf, "rbadtid ", blen);
        if (err & INFINIPATH_E_RBADVERSION)
                strlcat(buf, "rbadversion ", blen);
        if (err & INFINIPATH_E_RHDR)
                strlcat(buf, "rhdr ", blen);
        if (err & INFINIPATH_E_RLONGPKTLEN)
                strlcat(buf, "rlongpktlen ", blen);
        if (err & INFINIPATH_E_RSHORTPKTLEN)
                strlcat(buf, "rshortpktlen ", blen);
        if (err & INFINIPATH_E_RMAXPKTLEN)
                strlcat(buf, "rmaxpktlen ", blen);
        if (err & INFINIPATH_E_RMINPKTLEN)
                strlcat(buf, "rminpktlen ", blen);
        if (err & INFINIPATH_E_RFORMATERR)
                strlcat(buf, "rformaterr ", blen);
        if (err & INFINIPATH_E_RUNSUPVL)
                strlcat(buf, "runsupvl ", blen);
        if (err & INFINIPATH_E_RUNEXPCHAR)
                strlcat(buf, "runexpchar ", blen);
        if (err & INFINIPATH_E_RIBFLOW)
                strlcat(buf, "ribflow ", blen);
        if (err & INFINIPATH_E_REBP)
                strlcat(buf, "EBP ", blen);
        if (err & INFINIPATH_E_SUNDERRUN)
                strlcat(buf, "sunderrun ", blen);
        if (err & INFINIPATH_E_SPIOARMLAUNCH)
                strlcat(buf, "spioarmlaunch ", blen);
        if (err & INFINIPATH_E_SUNEXPERRPKTNUM)
                strlcat(buf, "sunexperrpktnum ", blen);
        if (err & INFINIPATH_E_SDROPPEDDATAPKT)
                strlcat(buf, "sdroppeddatapkt ", blen);
        if (err & INFINIPATH_E_SDROPPEDSMPPKT)
                strlcat(buf, "sdroppedsmppkt ", blen);
        if (err & INFINIPATH_E_SMAXPKTLEN)
                strlcat(buf, "smaxpktlen ", blen);
        if (err & INFINIPATH_E_SMINPKTLEN)
                strlcat(buf, "sminpktlen ", blen);
        if (err & INFINIPATH_E_SUNSUPVL)
                strlcat(buf, "sunsupVL ", blen);
        if (err & INFINIPATH_E_SPKTLEN)
                strlcat(buf, "spktlen ", blen);
        if (err & INFINIPATH_E_INVALIDADDR)
                strlcat(buf, "invalidaddr ", blen);
        if (err & INFINIPATH_E_RICRC)
                strlcat(buf, "CRC ", blen);
        if (err & INFINIPATH_E_RVCRC)
                strlcat(buf, "VCRC ", blen);
        if (err & INFINIPATH_E_RRCVEGRFULL)
                strlcat(buf, "rcvegrfull ", blen);
        if (err & INFINIPATH_E_RRCVHDRFULL)
                strlcat(buf, "rcvhdrfull ", blen);
        if (err & INFINIPATH_E_IBSTATUSCHANGED)
                strlcat(buf, "ibcstatuschg ", blen);
        if (err & INFINIPATH_E_RIBLOSTLINK)
                strlcat(buf, "riblostlink ", blen);
        if (err & INFINIPATH_E_HARDWARE)
                strlcat(buf, "hardware ", blen);
        if (err & INFINIPATH_E_RESET)
                strlcat(buf, "reset ", blen);
}

/**
 * get_rhf_errstring - decode RHF errors
 * @err: the err number
 * @msg: the output buffer
 * @len: the length of the output buffer
 *
 * only used one place now, may want more later
 */
static void get_rhf_errstring(u32 err, char *msg, size_t len)
{
        /* if no errors, and so don't need to check what's first */
        *msg = '\0';

        if (err & INFINIPATH_RHF_H_ICRCERR)
                strlcat(msg, "icrcerr ", len);
        if (err & INFINIPATH_RHF_H_VCRCERR)
                strlcat(msg, "vcrcerr ", len);
        if (err & INFINIPATH_RHF_H_PARITYERR)
                strlcat(msg, "parityerr ", len);
        if (err & INFINIPATH_RHF_H_LENERR)
                strlcat(msg, "lenerr ", len);
        if (err & INFINIPATH_RHF_H_MTUERR)
                strlcat(msg, "mtuerr ", len);
        if (err & INFINIPATH_RHF_H_IHDRERR)
                /* infinipath hdr checksum error */
                strlcat(msg, "ipathhdrerr ", len);
        if (err & INFINIPATH_RHF_H_TIDERR)
                strlcat(msg, "tiderr ", len);
        if (err & INFINIPATH_RHF_H_MKERR)
                /* bad port, offset, etc. */
                strlcat(msg, "invalid ipathhdr ", len);
        if (err & INFINIPATH_RHF_H_IBERR)
                strlcat(msg, "iberr ", len);
        if (err & INFINIPATH_RHF_L_SWA)
                strlcat(msg, "swA ", len);
        if (err & INFINIPATH_RHF_L_SWB)
                strlcat(msg, "swB ", len);
}

/**
 * ipath_get_egrbuf - get an eager buffer
 * @dd: the infinipath device
 * @bufnum: the eager buffer to get
 * @err: unused
 *
 * must only be called if ipath_pd[port] is known to be allocated
 */
static inline void *ipath_get_egrbuf(struct ipath_devdata *dd, u32 bufnum,
                                     int err)
{
        return dd->ipath_port0_skbs ?
                (void *)dd->ipath_port0_skbs[bufnum]->data : NULL;
}

/**
 * ipath_alloc_skb - allocate an skb and buffer with possible constraints
 * @dd: the infinipath device
 * @gfp_mask: the sk_buff SFP mask
 */
struct sk_buff *ipath_alloc_skb(struct ipath_devdata *dd,
                                gfp_t gfp_mask)
{
        struct sk_buff *skb;
        u32 len;

        /*
         * Only fully supported way to handle this is to allocate lots
         * extra, align as needed, and then do skb_reserve().  That wastes
         * a lot of memory...  I'll have to hack this into infinipath_copy
         * also.
         */

        /*
         * We need 4 extra bytes for unaligned transfer copying
         */
        if (dd->ipath_flags & IPATH_4BYTE_TID) {
                /* we need a 4KB multiple alignment, and there is no way
                 * to do it except to allocate extra and then skb_reserve
                 * enough to bring it up to the right alignment.
                 */
                len = dd->ipath_ibmaxlen + 4 + (1 << 11) - 1;
        }
        else
                len = dd->ipath_ibmaxlen + 4;
        skb = __dev_alloc_skb(len, gfp_mask);
        if (!skb) {
                ipath_dev_err(dd, "Failed to allocate skbuff, length %u\n",
                              len);
                goto bail;
        }
        if (dd->ipath_flags & IPATH_4BYTE_TID) {
                u32 una = ((1 << 11) - 1) & (unsigned long)(skb->data + 4);
                if (una)
                        skb_reserve(skb, 4 + (1 << 11) - una);
                else
                        skb_reserve(skb, 4);
        } else
                skb_reserve(skb, 4);

bail:
        return skb;
}

/**
 * ipath_rcv_layer - receive a packet for the layered (ethernet) driver
 * @dd: the infinipath device
 * @etail: the sk_buff number
 * @tlen: the total packet length
 * @hdr: the ethernet header
 *
 * Separate routine for better overall optimization
 */
static void ipath_rcv_layer(struct ipath_devdata *dd, u32 etail,
                            u32 tlen, struct ether_header *hdr)
{
        u32 elen;
        u8 pad, *bthbytes;
        struct sk_buff *skb, *nskb;

        if (dd->ipath_port0_skbs && hdr->sub_opcode == OPCODE_ENCAP) {
                /*
                 * Allocate a new sk_buff to replace the one we give
                 * to the network stack.
                 */
                nskb = ipath_alloc_skb(dd, GFP_ATOMIC);
                if (!nskb) {
                        /* count OK packets that we drop */
                        ipath_stats.sps_krdrops++;
                        return;
                }

                bthbytes = (u8 *) hdr->bth;
                pad = (bthbytes[1] >> 4) & 3;
                /* +CRC32 */
                elen = tlen - (sizeof(*hdr) + pad + sizeof(u32));

                skb = dd->ipath_port0_skbs[etail];
                dd->ipath_port0_skbs[etail] = nskb;
                skb_put(skb, elen);

                dd->ipath_f_put_tid(dd, etail + (u64 __iomem *)
                                    ((char __iomem *) dd->ipath_kregbase
                                     + dd->ipath_rcvegrbase), 0,
                                    virt_to_phys(nskb->data));

                __ipath_layer_rcv(dd, hdr, skb);

                /* another ether packet received */
                ipath_stats.sps_ether_rpkts++;
        }
        else if (hdr->sub_opcode == OPCODE_LID_ARP)
                __ipath_layer_rcv_lid(dd, hdr);
}

/*
 * ipath_kreceive - receive a packet
 * @dd: the infinipath device
 *
 * called from interrupt handler for errors or receive interrupt
 */
void ipath_kreceive(struct ipath_devdata *dd)
{
        u64 *rc;
        void *ebuf;
        const u32 rsize = dd->ipath_rcvhdrentsize;      /* words */
        const u32 maxcnt = dd->ipath_rcvhdrcnt * rsize; /* words */
        u32 etail = -1, l, hdrqtail;
        struct ips_message_header *hdr;
        u32 eflags, i, etype, tlen, pkttot = 0;
        static u64 totcalls;    /* stats, may eventually remove */
        char emsg[128];

        if (!dd->ipath_hdrqtailptr) {
                ipath_dev_err(dd,
                              "hdrqtailptr not set, can't do receives\n");
                goto bail;
        }

        /* There is already a thread processing this queue. */
        if (test_and_set_bit(0, &dd->ipath_rcv_pending))
                goto bail;

        if (dd->ipath_port0head ==
            (u32)le64_to_cpu(*dd->ipath_hdrqtailptr))
                goto done;

gotmore:
        /*
         * read only once at start.  If in flood situation, this helps
         * performance slightly.  If more arrive while we are processing,
         * we'll come back here and do them
         */
        hdrqtail = (u32)le64_to_cpu(*dd->ipath_hdrqtailptr);

        for (i = 0, l = dd->ipath_port0head; l != hdrqtail; i++) {
                u32 qp;
                u8 *bthbytes;

                rc = (u64 *) (dd->ipath_pd[0]->port_rcvhdrq + (l << 2));
                hdr = (struct ips_message_header *)&rc[1];
                /*
                 * could make a network order version of IPATH_KD_QP, and
                 * do the obvious shift before masking to speed this up.
                 */
                qp = ntohl(hdr->bth[1]) & 0xffffff;
                bthbytes = (u8 *) hdr->bth;

                eflags = ips_get_hdr_err_flags((__le32 *) rc);
                etype = ips_get_rcv_type((__le32 *) rc);
                /* total length */
                tlen = ips_get_length_in_bytes((__le32 *) rc);
                ebuf = NULL;
                if (etype != RCVHQ_RCV_TYPE_EXPECTED) {
                        /*
                         * it turns out that the chips uses an eager buffer
                         * for all non-expected packets, whether it "needs"
                         * one or not.  So always get the index, but don't
                         * set ebuf (so we try to copy data) unless the
                         * length requires it.
                         */
                        etail = ips_get_index((__le32 *) rc);
                        if (tlen > sizeof(*hdr) ||
                            etype == RCVHQ_RCV_TYPE_NON_KD)
                                ebuf = ipath_get_egrbuf(dd, etail, 0);
                }

                /*
                 * both tiderr and ipathhdrerr are set for all plain IB
                 * packets; only ipathhdrerr should be set.
                 */

                if (etype != RCVHQ_RCV_TYPE_NON_KD && etype !=
                    RCVHQ_RCV_TYPE_ERROR && ips_get_ipath_ver(
                            hdr->iph.ver_port_tid_offset) !=
                    IPS_PROTO_VERSION) {
                        ipath_cdbg(PKT, "Bad InfiniPath protocol version "
                                   "%x\n", etype);
                }

                if (eflags & ~(INFINIPATH_RHF_H_TIDERR |
                               INFINIPATH_RHF_H_IHDRERR)) {
                        get_rhf_errstring(eflags, emsg, sizeof emsg);
                        ipath_cdbg(PKT, "RHFerrs %x hdrqtail=%x typ=%u "
                                   "tlen=%x opcode=%x egridx=%x: %s\n",
                                   eflags, l, etype, tlen, bthbytes[0],
                                   ips_get_index((__le32 *) rc), emsg);
                } else if (etype == RCVHQ_RCV_TYPE_NON_KD) {
                                int ret = __ipath_verbs_rcv(dd, rc + 1,
                                                            ebuf, tlen);
                                if (ret == -ENODEV)
                                        ipath_cdbg(VERBOSE,
                                                   "received IB packet, "
                                                   "not SMA (QP=%x)\n", qp);
                } else if (etype == RCVHQ_RCV_TYPE_EAGER) {
                        if (qp == IPATH_KD_QP &&
                            bthbytes[0] == ipath_layer_rcv_opcode &&
                            ebuf)
                                ipath_rcv_layer(dd, etail, tlen,
                                                (struct ether_header *)hdr);
                        else
                                ipath_cdbg(PKT, "typ %x, opcode %x (eager, "
                                           "qp=%x), len %x; ignored\n",
                                           etype, bthbytes[0], qp, tlen);
                }
                else if (etype == RCVHQ_RCV_TYPE_EXPECTED)
                        ipath_dbg("Bug: Expected TID, opcode %x; ignored\n",
                                  be32_to_cpu(hdr->bth[0]) & 0xff);
                else if (eflags & (INFINIPATH_RHF_H_TIDERR |
                                   INFINIPATH_RHF_H_IHDRERR)) {
                        /*
                         * This is a type 3 packet, only the LRH is in the
                         * rcvhdrq, the rest of the header is in the eager
                         * buffer.
                         */
                        u8 opcode;
                        if (ebuf) {
                                bthbytes = (u8 *) ebuf;
                                opcode = *bthbytes;
                        }
                        else
                                opcode = 0;
                        get_rhf_errstring(eflags, emsg, sizeof emsg);
                        ipath_dbg("Err %x (%s), opcode %x, egrbuf %x, "
                                  "len %x\n", eflags, emsg, opcode, etail,
                                  tlen);
                } else {
                        /*
                         * error packet, type of error  unknown.
                         * Probably type 3, but we don't know, so don't
                         * even try to print the opcode, etc.
                         */
                        ipath_dbg("Error Pkt, but no eflags! egrbuf %x, "
                                  "len %x\nhdrq@%lx;hdrq+%x rhf: %llx; "
                                  "hdr %llx %llx %llx %llx %llx\n",
                                  etail, tlen, (unsigned long) rc, l,
                                  (unsigned long long) rc[0],
                                  (unsigned long long) rc[1],
                                  (unsigned long long) rc[2],
                                  (unsigned long long) rc[3],
                                  (unsigned long long) rc[4],
                                  (unsigned long long) rc[5]);
                }
                l += rsize;
                if (l >= maxcnt)
                        l = 0;
                /*
                 * update for each packet, to help prevent overflows if we
                 * have lots of packets.
                 */
                (void)ipath_write_ureg(dd, ur_rcvhdrhead,
                                       dd->ipath_rhdrhead_intr_off | l, 0);
                if (etype != RCVHQ_RCV_TYPE_EXPECTED)
                        (void)ipath_write_ureg(dd, ur_rcvegrindexhead,
                                               etail, 0);
        }

        pkttot += i;

        dd->ipath_port0head = l;

        if (hdrqtail != (u32)le64_to_cpu(*dd->ipath_hdrqtailptr))
                /* more arrived while we handled first batch */
                goto gotmore;

        if (pkttot > ipath_stats.sps_maxpkts_call)
                ipath_stats.sps_maxpkts_call = pkttot;
        ipath_stats.sps_port0pkts += pkttot;
        ipath_stats.sps_avgpkts_call =
                ipath_stats.sps_port0pkts / ++totcalls;

done:
        clear_bit(0, &dd->ipath_rcv_pending);
        smp_mb__after_clear_bit();

bail:;
}

/**
 * ipath_update_pio_bufs - update shadow copy of the PIO availability map
 * @dd: the infinipath device
 *
 * called whenever our local copy indicates we have run out of send buffers
 * NOTE: This can be called from interrupt context by some code
 * and from non-interrupt context by ipath_getpiobuf().
 */

static void ipath_update_pio_bufs(struct ipath_devdata *dd)
{
        unsigned long flags;
        int i;
        const unsigned piobregs = (unsigned)dd->ipath_pioavregs;

        /* If the generation (check) bits have changed, then we update the
         * busy bit for the corresponding PIO buffer.  This algorithm will
         * modify positions to the value they already have in some cases
         * (i.e., no change), but it's faster than changing only the bits
         * that have changed.
         *
         * We would like to do this atomicly, to avoid spinlocks in the
         * critical send path, but that's not really possible, given the
         * type of changes, and that this routine could be called on
         * multiple cpu's simultaneously, so we lock in this routine only,
         * to avoid conflicting updates; all we change is the shadow, and
         * it's a single 64 bit memory location, so by definition the update
         * is atomic in terms of what other cpu's can see in testing the
         * bits.  The spin_lock overhead isn't too bad, since it only
         * happens when all buffers are in use, so only cpu overhead, not
         * latency or bandwidth is affected.
         */
#define _IPATH_ALL_CHECKBITS 0x5555555555555555ULL
        if (!dd->ipath_pioavailregs_dma) {
                ipath_dbg("Update shadow pioavail, but regs_dma NULL!\n");
                return;
        }
        if (ipath_debug & __IPATH_VERBDBG) {
                /* only if packet debug and verbose */
                volatile __le64 *dma = dd->ipath_pioavailregs_dma;
                unsigned long *shadow = dd->ipath_pioavailshadow;

                ipath_cdbg(PKT, "Refill avail, dma0=%llx shad0=%lx, "
                           "d1=%llx s1=%lx, d2=%llx s2=%lx, d3=%llx "
                           "s3=%lx\n",
                           (unsigned long long) le64_to_cpu(dma[0]),
                           shadow[0],
                           (unsigned long long) le64_to_cpu(dma[1]),
                           shadow[1],
                           (unsigned long long) le64_to_cpu(dma[2]),
                           shadow[2],
                           (unsigned long long) le64_to_cpu(dma[3]),
                           shadow[3]);
                if (piobregs > 4)
                        ipath_cdbg(
                                PKT, "2nd group, dma4=%llx shad4=%lx, "
                                "d5=%llx s5=%lx, d6=%llx s6=%lx, "
                                "d7=%llx s7=%lx\n",
                                (unsigned long long) le64_to_cpu(dma[4]),
                                shadow[4],
                                (unsigned long long) le64_to_cpu(dma[5]),
                                shadow[5],
                                (unsigned long long) le64_to_cpu(dma[6]),
                                shadow[6],
                                (unsigned long long) le64_to_cpu(dma[7]),
                                shadow[7]);
        }
        spin_lock_irqsave(&ipath_pioavail_lock, flags);
        for (i = 0; i < piobregs; i++) {
                u64 pchbusy, pchg, piov, pnew;
                /*
                 * Chip Errata: bug 6641; even and odd qwords>3 are swapped
                 */
                if (i > 3) {
                        if (i & 1)
                                piov = le64_to_cpu(
                                        dd->ipath_pioavailregs_dma[i - 1]);
                        else
                                piov = le64_to_cpu(
                                        dd->ipath_pioavailregs_dma[i + 1]);
                } else
                        piov = le64_to_cpu(dd->ipath_pioavailregs_dma[i]);
                pchg = _IPATH_ALL_CHECKBITS &
                        ~(dd->ipath_pioavailshadow[i] ^ piov);
                pchbusy = pchg << INFINIPATH_SENDPIOAVAIL_BUSY_SHIFT;
                if (pchg && (pchbusy & dd->ipath_pioavailshadow[i])) {
                        pnew = dd->ipath_pioavailshadow[i] & ~pchbusy;
                        pnew |= piov & pchbusy;
                        dd->ipath_pioavailshadow[i] = pnew;
                }
        }
        spin_unlock_irqrestore(&ipath_pioavail_lock, flags);
}

/**
 * ipath_setrcvhdrsize - set the receive header size
 * @dd: the infinipath device
 * @rhdrsize: the receive header size
 *
 * called from user init code, and also layered driver init
 */
int ipath_setrcvhdrsize(struct ipath_devdata *dd, unsigned rhdrsize)
{
        int ret = 0;

        if (dd->ipath_flags & IPATH_RCVHDRSZ_SET) {
                if (dd->ipath_rcvhdrsize != rhdrsize) {
                        dev_info(&dd->pcidev->dev,
                                 "Error: can't set protocol header "
                                 "size %u, already %u\n",
                                 rhdrsize, dd->ipath_rcvhdrsize);
                        ret = -EAGAIN;
                } else
                        ipath_cdbg(VERBOSE, "Reuse same protocol header "
                                   "size %u\n", dd->ipath_rcvhdrsize);
        } else if (rhdrsize > (dd->ipath_rcvhdrentsize -
                               (sizeof(u64) / sizeof(u32)))) {
                ipath_dbg("Error: can't set protocol header size %u "
                          "(> max %u)\n", rhdrsize,
                          dd->ipath_rcvhdrentsize -
                          (u32) (sizeof(u64) / sizeof(u32)));
                ret = -EOVERFLOW;
        } else {
                dd->ipath_flags |= IPATH_RCVHDRSZ_SET;
                dd->ipath_rcvhdrsize = rhdrsize;
                ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvhdrsize,
                                 dd->ipath_rcvhdrsize);
                ipath_cdbg(VERBOSE, "Set protocol header size to %u\n",
                           dd->ipath_rcvhdrsize);
        }
        return ret;
}

/**
 * ipath_getpiobuf - find an available pio buffer
 * @dd: the infinipath device
 * @pbufnum: the buffer number is placed here
 *
 * do appropriate marking as busy, etc.
 * returns buffer number if one found (>=0), negative number is error.
 * Used by ipath_sma_send_pkt and ipath_layer_send
 */
u32 __iomem *ipath_getpiobuf(struct ipath_devdata *dd, u32 * pbufnum)
{
        int i, j, starti, updated = 0;
        unsigned piobcnt, iter;
        unsigned long flags;
        unsigned long *shadow = dd->ipath_pioavailshadow;
        u32 __iomem *buf;

        piobcnt = (unsigned)(dd->ipath_piobcnt2k
                             + dd->ipath_piobcnt4k);
        starti = dd->ipath_lastport_piobuf;
        iter = piobcnt - starti;
        if (dd->ipath_upd_pio_shadow) {
                /*
                 * Minor optimization.  If we had no buffers on last call,
                 * start out by doing the update; continue and do scan even
                 * if no buffers were updated, to be paranoid
                 */
                ipath_update_pio_bufs(dd);
                /* we scanned here, don't do it at end of scan */
                updated = 1;
                i = starti;
        } else
                i = dd->ipath_lastpioindex;

rescan:
        /*
         * while test_and_set_bit() is atomic, we do that and then the
         * change_bit(), and the pair is not.  See if this is the cause
         * of the remaining armlaunch errors.
         */
        spin_lock_irqsave(&ipath_pioavail_lock, flags);
        for (j = 0; j < iter; j++, i++) {
                if (i >= piobcnt)
                        i = starti;
                /*
                 * To avoid bus lock overhead, we first find a candidate
                 * buffer, then do the test and set, and continue if that
                 * fails.
                 */
                if (test_bit((2 * i) + 1, shadow) ||
                    test_and_set_bit((2 * i) + 1, shadow))
                        continue;
                /* flip generation bit */
                change_bit(2 * i, shadow);
                break;
        }
        spin_unlock_irqrestore(&ipath_pioavail_lock, flags);

        if (j == iter) {
                volatile __le64 *dma = dd->ipath_pioavailregs_dma;

                /*
                 * first time through; shadow exhausted, but may be real
                 * buffers available, so go see; if any updated, rescan
                 * (once)
                 */
                if (!updated) {
                        ipath_update_pio_bufs(dd);
                        updated = 1;
                        i = starti;
                        goto rescan;
                }
                dd->ipath_upd_pio_shadow = 1;
                /*
                 * not atomic, but if we lose one once in a while, that's OK
                 */
                ipath_stats.sps_nopiobufs++;
                if (!(++dd->ipath_consec_nopiobuf % 100000)) {
                        ipath_dbg(
                                "%u pio sends with no bufavail; dmacopy: "
                                "%llx %llx %llx %llx; shadow:  "
                                "%lx %lx %lx %lx\n",
                                dd->ipath_consec_nopiobuf,
                                (unsigned long long) le64_to_cpu(dma[0]),
                                (unsigned long long) le64_to_cpu(dma[1]),
                                (unsigned long long) le64_to_cpu(dma[2]),
                                (unsigned long long) le64_to_cpu(dma[3]),
                                shadow[0], shadow[1], shadow[2],
                                shadow[3]);
                        /*
                         * 4 buffers per byte, 4 registers above, cover rest
                         * below
                         */
                        if ((dd->ipath_piobcnt2k + dd->ipath_piobcnt4k) >
                            (sizeof(shadow[0]) * 4 * 4))
                                ipath_dbg("2nd group: dmacopy: %llx %llx "
                                          "%llx %llx; shadow: %lx %lx "
                                          "%lx %lx\n",
                                          (unsigned long long)
                                          le64_to_cpu(dma[4]),
                                          (unsigned long long)
                                          le64_to_cpu(dma[5]),
                                          (unsigned long long)
                                          le64_to_cpu(dma[6]),
                                          (unsigned long long)
                                          le64_to_cpu(dma[7]),
                                          shadow[4], shadow[5],
                                          shadow[6], shadow[7]);
                }
                buf = NULL;
                goto bail;
        }

        if (updated)
                /*
                 * ran out of bufs, now some (at least this one we just
                 * got) are now available, so tell the layered driver.
                 */
                __ipath_layer_intr(dd, IPATH_LAYER_INT_SEND_CONTINUE);

        /*
         * set next starting place.  Since it's just an optimization,
         * it doesn't matter who wins on this, so no locking
         */
        dd->ipath_lastpioindex = i + 1;
        if (dd->ipath_upd_pio_shadow)
                dd->ipath_upd_pio_shadow = 0;
        if (dd->ipath_consec_nopiobuf)
                dd->ipath_consec_nopiobuf = 0;
        if (i < dd->ipath_piobcnt2k)
                buf = (u32 __iomem *) (dd->ipath_pio2kbase +
                                       i * dd->ipath_palign);
        else
                buf = (u32 __iomem *)
                        (dd->ipath_pio4kbase +
                         (i - dd->ipath_piobcnt2k) * dd->ipath_4kalign);
        ipath_cdbg(VERBOSE, "Return piobuf%u %uk @ %p\n",
                   i, (i < dd->ipath_piobcnt2k) ? 2 : 4, buf);
        if (pbufnum)
                *pbufnum = i;

bail:
        return buf;
}

/**
 * ipath_create_rcvhdrq - create a receive header queue
 * @dd: the infinipath device
 * @pd: the port data
 *
 * this *must* be physically contiguous memory, and for now,
 * that limits it to what kmalloc can do.
 */
int ipath_create_rcvhdrq(struct ipath_devdata *dd,
                         struct ipath_portdata *pd)
{
        int ret = 0, amt;

        amt = ALIGN(dd->ipath_rcvhdrcnt * dd->ipath_rcvhdrentsize *
                    sizeof(u32), PAGE_SIZE);
        if (!pd->port_rcvhdrq) {
                /*
                 * not using REPEAT isn't viable; at 128KB, we can easily
                 * fail this.  The problem with REPEAT is we can block here
                 * "forever".  There isn't an inbetween, unfortunately.  We
                 * could reduce the risk by never freeing the rcvhdrq except
                 * at unload, but even then, the first time a port is used,
                 * we could delay for some time...
                 */
                gfp_t gfp_flags = GFP_USER | __GFP_COMP;

                pd->port_rcvhdrq = dma_alloc_coherent(
                        &dd->pcidev->dev, amt, &pd->port_rcvhdrq_phys,
                        gfp_flags);

                if (!pd->port_rcvhdrq) {
                        ipath_dev_err(dd, "attempt to allocate %d bytes "
                                      "for port %u rcvhdrq failed\n",
                                      amt, pd->port_port);
                        ret = -ENOMEM;
                        goto bail;
                }

                pd->port_rcvhdrq_size = amt;

                ipath_cdbg(VERBOSE, "%d pages at %p (phys %lx) size=%lu "
                           "for port %u rcvhdr Q\n",
                           amt >> PAGE_SHIFT, pd->port_rcvhdrq,
                           (unsigned long) pd->port_rcvhdrq_phys,
                           (unsigned long) pd->port_rcvhdrq_size,
                           pd->port_port);
        } else {
                /*
                 * clear for security, sanity, and/or debugging, each
                 * time we reuse
                 */
                memset(pd->port_rcvhdrq, 0, amt);
        }

        /*
         * tell chip each time we init it, even if we are re-using previous
         * memory (we zero it at process close)
         */
        ipath_cdbg(VERBOSE, "writing port %d rcvhdraddr as %lx\n",
                   pd->port_port, (unsigned long) pd->port_rcvhdrq_phys);
        ipath_write_kreg_port(dd, dd->ipath_kregs->kr_rcvhdraddr,
                              pd->port_port, pd->port_rcvhdrq_phys);

        ret = 0;
bail:
        return ret;
}

int ipath_waitfor_complete(struct ipath_devdata *dd, ipath_kreg reg_id,
                           u64 bits_to_wait_for, u64 * valp)
{
        unsigned long timeout;
        u64 lastval, val;
        int ret;

        lastval = ipath_read_kreg64(dd, reg_id);
        /* wait a ridiculously long time */
        timeout = jiffies + msecs_to_jiffies(5);
        do {
                val = ipath_read_kreg64(dd, reg_id);
                /* set so they have something, even on failures. */
                *valp = val;
                if ((val & bits_to_wait_for) == bits_to_wait_for) {
                        ret = 0;
                        break;
                }
                if (val != lastval)
                        ipath_cdbg(VERBOSE, "Changed from %llx to %llx, "
                                   "waiting for %llx bits\n",
                                   (unsigned long long) lastval,
                                   (unsigned long long) val,
                                   (unsigned long long) bits_to_wait_for);
                cond_resched();
                if (time_after(jiffies, timeout)) {
                        ipath_dbg("Didn't get bits %llx in register 0x%x, "
                                  "got %llx\n",
                                  (unsigned long long) bits_to_wait_for,
                                  reg_id, (unsigned long long) *valp);
                        ret = -ENODEV;
                        break;
                }
        } while (1);

        return ret;
}

/**
 * ipath_waitfor_mdio_cmdready - wait for last command to complete
 * @dd: the infinipath device
 *
 * Like ipath_waitfor_complete(), but we wait for the CMDVALID bit to go
 * away indicating the last command has completed.  It doesn't return data
 */
int ipath_waitfor_mdio_cmdready(struct ipath_devdata *dd)
{
        unsigned long timeout;
        u64 val;
        int ret;

        /* wait a ridiculously long time */
        timeout = jiffies + msecs_to_jiffies(5);
        do {
                val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_mdio);
                if (!(val & IPATH_MDIO_CMDVALID)) {
                        ret = 0;
                        break;
                }
                cond_resched();
                if (time_after(jiffies, timeout)) {
                        ipath_dbg("CMDVALID stuck in mdio reg? (%llx)\n",
                                  (unsigned long long) val);
                        ret = -ENODEV;
                        break;
                }
        } while (1);

        return ret;
}

void ipath_set_ib_lstate(struct ipath_devdata *dd, int which)
{
        static const char *what[4] = {
                [0] = "DOWN",
                [INFINIPATH_IBCC_LINKCMD_INIT] = "INIT",
                [INFINIPATH_IBCC_LINKCMD_ARMED] = "ARMED",
                [INFINIPATH_IBCC_LINKCMD_ACTIVE] = "ACTIVE"
        };
        ipath_cdbg(SMA, "Trying to move unit %u to %s, current ltstate "
                   "is %s\n", dd->ipath_unit,
                   what[(which >> INFINIPATH_IBCC_LINKCMD_SHIFT) &
                        INFINIPATH_IBCC_LINKCMD_MASK],
                   ipath_ibcstatus_str[
                           (ipath_read_kreg64
                            (dd, dd->ipath_kregs->kr_ibcstatus) >>
                            INFINIPATH_IBCS_LINKTRAININGSTATE_SHIFT) &
                           INFINIPATH_IBCS_LINKTRAININGSTATE_MASK]);

        ipath_write_kreg(dd, dd->ipath_kregs->kr_ibcctrl,
                         dd->ipath_ibcctrl | which);
}

/**
 * ipath_read_kreg64_port - read a device's per-port 64-bit kernel register
 * @dd: the infinipath device
 * @regno: the register number to read
 * @port: the port containing the register
 *
 * Registers that vary with the chip implementation constants (port)
 * use this routine.
 */
u64 ipath_read_kreg64_port(const struct ipath_devdata *dd, ipath_kreg regno,
                           unsigned port)
{
        u16 where;

        if (port < dd->ipath_portcnt &&
            (regno == dd->ipath_kregs->kr_rcvhdraddr ||
             regno == dd->ipath_kregs->kr_rcvhdrtailaddr))
                where = regno + port;
        else
                where = -1;

        return ipath_read_kreg64(dd, where);
}

/**
 * ipath_write_kreg_port - write a device's per-port 64-bit kernel register
 * @dd: the infinipath device
 * @regno: the register number to write
 * @port: the port containing the register
 * @value: the value to write
 *
 * Registers that vary with the chip implementation constants (port)
 * use this routine.
 */
void ipath_write_kreg_port(const struct ipath_devdata *dd, ipath_kreg regno,
                          unsigned port, u64 value)
{
        u16 where;

        if (port < dd->ipath_portcnt &&
            (regno == dd->ipath_kregs->kr_rcvhdraddr ||
             regno == dd->ipath_kregs->kr_rcvhdrtailaddr))
                where = regno + port;
        else
                where = -1;

        ipath_write_kreg(dd, where, value);
}

/**
 * ipath_shutdown_device - shut down a device
 * @dd: the infinipath device
 *
 * This is called to make the device quiet when we are about to
 * unload the driver, and also when the device is administratively
 * disabled.   It does not free any data structures.
 * Everything it does has to be setup again by ipath_init_chip(dd,1)
 */
void ipath_shutdown_device(struct ipath_devdata *dd)
{
        u64 val;

        ipath_dbg("Shutting down the device\n");

        dd->ipath_flags |= IPATH_LINKUNK;
        dd->ipath_flags &= ~(IPATH_INITTED | IPATH_LINKDOWN |
                             IPATH_LINKINIT | IPATH_LINKARMED |
                             IPATH_LINKACTIVE);
        *dd->ipath_statusp &= ~(IPATH_STATUS_IB_CONF |
                                IPATH_STATUS_IB_READY);

        /* mask interrupts, but not errors */
        ipath_write_kreg(dd, dd->ipath_kregs->kr_intmask, 0ULL);

        dd->ipath_rcvctrl = 0;
        ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
                         dd->ipath_rcvctrl);

        /*
         * gracefully stop all sends allowing any in progress to trickle out
         * first.
         */
        ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl, 0ULL);
        /* flush it */
        val = ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
        /*
         * enough for anything that's going to trickle out to have actually
         * done so.
         */
        udelay(5);

        /*
         * abort any armed or launched PIO buffers that didn't go. (self
         * clearing).  Will cause any packet currently being transmitted to
         * go out with an EBP, and may also cause a short packet error on
         * the receiver.
         */
        ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
                         INFINIPATH_S_ABORT);

        ipath_set_ib_lstate(dd, INFINIPATH_IBCC_LINKINITCMD_DISABLE <<
                            INFINIPATH_IBCC_LINKINITCMD_SHIFT);

        /*
         * we are shutting down, so tell the layered driver.  We don't do
         * this on just a link state change, much like ethernet, a cable
         * unplug, etc. doesn't change driver state
         */
        ipath_layer_intr(dd, IPATH_LAYER_INT_IF_DOWN);

        /* disable IBC */
        dd->ipath_control &= ~INFINIPATH_C_LINKENABLE;
        ipath_write_kreg(dd, dd->ipath_kregs->kr_control,
                         dd->ipath_control);

        /*
         * clear SerdesEnable and turn the leds off; do this here because
         * we are unloading, so don't count on interrupts to move along
         * Turn the LEDs off explictly for the same reason.
         */
        dd->ipath_f_quiet_serdes(dd);
        dd->ipath_f_setextled(dd, 0, 0);

        if (dd->ipath_stats_timer_active) {
                del_timer_sync(&dd->ipath_stats_timer);
                dd->ipath_stats_timer_active = 0;
        }

        /*
         * clear all interrupts and errors, so that the next time the driver
         * is loaded or device is enabled, we know that whatever is set
         * happened while we were unloaded
         */
        ipath_write_kreg(dd, dd->ipath_kregs->kr_hwerrclear,
                         ~0ULL & ~INFINIPATH_HWE_MEMBISTFAILED);
        ipath_write_kreg(dd, dd->ipath_kregs->kr_errorclear, -1LL);
        ipath_write_kreg(dd, dd->ipath_kregs->kr_intclear, -1LL);
}

/**
 * ipath_free_pddata - free a port's allocated data
 * @dd: the infinipath device
 * @port: the port
 * @freehdrq: free the port data structure if true
 *
 * when closing, free up any allocated data for a port, if the
 * reference count goes to zero
 * Note: this also optionally frees the portdata itself!
 * Any changes here have to be matched up with the reinit case
 * of ipath_init_chip(), which calls this routine on reinit after reset.
 */
void ipath_free_pddata(struct ipath_devdata *dd, u32 port, int freehdrq)
{
        struct ipath_portdata *pd = dd->ipath_pd[port];

        if (!pd)
                return;
        if (freehdrq)
                /*
                 * only clear and free portdata if we are going to also
                 * release the hdrq, otherwise we leak the hdrq on each
                 * open/close cycle
                 */
                dd->ipath_pd[port] = NULL;
        if (freehdrq && pd->port_rcvhdrq) {
                ipath_cdbg(VERBOSE, "free closed port %d rcvhdrq @ %p "
                           "(size=%lu)\n", pd->port_port, pd->port_rcvhdrq,
                           (unsigned long) pd->port_rcvhdrq_size);
                dma_free_coherent(&dd->pcidev->dev, pd->port_rcvhdrq_size,
                                  pd->port_rcvhdrq, pd->port_rcvhdrq_phys);
                pd->port_rcvhdrq = NULL;
        }
        if (port && pd->port_rcvegrbuf) {
                /* always free this */
                if (pd->port_rcvegrbuf) {
                        unsigned e;

                        for (e = 0; e < pd->port_rcvegrbuf_chunks; e++) {
                                void *base = pd->port_rcvegrbuf[e];
                                size_t size = pd->port_rcvegrbuf_size;

                                ipath_cdbg(VERBOSE, "egrbuf free(%p, %lu), "
                                           "chunk %u/%u\n", base,
                                           (unsigned long) size,
                                           e, pd->port_rcvegrbuf_chunks);
                                dma_free_coherent(
                                        &dd->pcidev->dev, size, base,
                                        pd->port_rcvegrbuf_phys[e]);
                        }
                        vfree(pd->port_rcvegrbuf);
                        pd->port_rcvegrbuf = NULL;
                        vfree(pd->port_rcvegrbuf_phys);
                        pd->port_rcvegrbuf_phys = NULL;
                }
                pd->port_rcvegrbuf_chunks = 0;
        } else if (port == 0 && dd->ipath_port0_skbs) {
                unsigned e;
                struct sk_buff **skbs = dd->ipath_port0_skbs;

                dd->ipath_port0_skbs = NULL;
                ipath_cdbg(VERBOSE, "free closed port %d ipath_port0_skbs "
                           "@ %p\n", pd->port_port, skbs);
                for (e = 0; e < dd->ipath_rcvegrcnt; e++)
                        if (skbs[e])
                                dev_kfree_skb(skbs[e]);
                vfree(skbs);
        }
        if (freehdrq) {
                kfree(pd->port_tid_pg_list);
                kfree(pd);
        }
}

static int __init infinipath_init(void)
{
        int ret;

        ipath_dbg(KERN_INFO DRIVER_LOAD_MSG "%s", ipath_core_version);

        /*
         * These must be called before the driver is registered with
         * the PCI subsystem.
         */
        idr_init(&unit_table);
        if (!idr_pre_get(&unit_table, GFP_KERNEL)) {
                ret = -ENOMEM;
                goto bail;
        }

        ret = pci_register_driver(&ipath_driver);
        if (ret < 0) {
                printk(KERN_ERR IPATH_DRV_NAME
                       ": Unable to register driver: error %d\n", -ret);
                goto bail_unit;
        }

        ret = ipath_driver_create_group(&ipath_driver.driver);
        if (ret < 0) {
                printk(KERN_ERR IPATH_DRV_NAME ": Unable to create driver "
                       "sysfs entries: error %d\n", -ret);
                goto bail_pci;
        }

        ret = ipath_init_ipathfs();
        if (ret < 0) {
                printk(KERN_ERR IPATH_DRV_NAME ": Unable to create "
                       "ipathfs: error %d\n", -ret);
                goto bail_group;
        }

        goto bail;

bail_group:
        ipath_driver_remove_group(&ipath_driver.driver);

bail_pci:
        pci_unregister_driver(&ipath_driver);

bail_unit:
        idr_destroy(&unit_table);

bail:
        return ret;
}

static void cleanup_device(struct ipath_devdata *dd)
{
        int port;

        ipath_shutdown_device(dd);

        if (*dd->ipath_statusp & IPATH_STATUS_CHIP_PRESENT) {
                /* can't do anything more with chip; needs re-init */
                *dd->ipath_statusp &= ~IPATH_STATUS_CHIP_PRESENT;
                if (dd->ipath_kregbase) {
                        /*
                         * if we haven't already cleaned up before these are
                         * to ensure any register reads/writes "fail" until
                         * re-init
                         */
                        dd->ipath_kregbase = NULL;
                        dd->ipath_kregvirt = NULL;
                        dd->ipath_uregbase = 0;
                        dd->ipath_sregbase = 0;
                        dd->ipath_cregbase = 0;
                        dd->ipath_kregsize = 0;
                }
                ipath_disable_wc(dd);
        }

        if (dd->ipath_pioavailregs_dma) {
                dma_free_coherent(&dd->pcidev->dev, PAGE_SIZE,
                                  (void *) dd->ipath_pioavailregs_dma,
                                  dd->ipath_pioavailregs_phys);
                dd->ipath_pioavailregs_dma = NULL;
        }

        if (dd->ipath_pageshadow) {
                struct page **tmpp = dd->ipath_pageshadow;
                int i, cnt = 0;

                ipath_cdbg(VERBOSE, "Unlocking any expTID pages still "
                           "locked\n");
                for (port = 0; port < dd->ipath_cfgports; port++) {
                        int port_tidbase = port * dd->ipath_rcvtidcnt;
                        int maxtid = port_tidbase + dd->ipath_rcvtidcnt;
                        for (i = port_tidbase; i < maxtid; i++) {
                                if (!tmpp[i])
                                        continue;
                                ipath_release_user_pages(&tmpp[i], 1);
                                tmpp[i] = NULL;
                                cnt++;
                        }
                }
                if (cnt) {
                        ipath_stats.sps_pageunlocks += cnt;
                        ipath_cdbg(VERBOSE, "There were still %u expTID "
                                   "entries locked\n", cnt);
                }
                if (ipath_stats.sps_pagelocks ||
                    ipath_stats.sps_pageunlocks)
                        ipath_cdbg(VERBOSE, "%llu pages locked, %llu "
                                   "unlocked via ipath_m{un}lock\n",
                                   (unsigned long long)
                                   ipath_stats.sps_pagelocks,
                                   (unsigned long long)
                                   ipath_stats.sps_pageunlocks);

                ipath_cdbg(VERBOSE, "Free shadow page tid array at %p\n",
                           dd->ipath_pageshadow);
                vfree(dd->ipath_pageshadow);
                dd->ipath_pageshadow = NULL;
        }

        /*
         * free any resources still in use (usually just kernel ports)
         * at unload
         */
        for (port = 0; port < dd->ipath_cfgports; port++)
                ipath_free_pddata(dd, port, 1);
        kfree(dd->ipath_pd);
        /*
         * debuggability, in case some cleanup path tries to use it
         * after this
         */
        dd->ipath_pd = NULL;
}

static void __exit infinipath_cleanup(void)
{
        struct ipath_devdata *dd, *tmp;
        unsigned long flags;

        ipath_exit_ipathfs();

        ipath_driver_remove_group(&ipath_driver.driver);

        spin_lock_irqsave(&ipath_devs_lock, flags);

        /*
         * turn off rcv, send, and interrupts for all ports, all drivers
         * should also hard reset the chip here?
         * free up port 0 (kernel) rcvhdr, egr bufs, and eventually tid bufs
         * for all versions of the driver, if they were allocated
         */
        list_for_each_entry_safe(dd, tmp, &ipath_dev_list, ipath_list) {
                spin_unlock_irqrestore(&ipath_devs_lock, flags);

                if (dd->ipath_kregbase)
                        cleanup_device(dd);

                if (dd->pcidev) {
                        if (dd->pcidev->irq) {
                                ipath_cdbg(VERBOSE,
                                           "unit %u free_irq of irq %x\n",
                                           dd->ipath_unit, dd->pcidev->irq);
                                free_irq(dd->pcidev->irq, dd);
                        } else
                                ipath_dbg("irq is 0, not doing free_irq "
                                          "for unit %u\n", dd->ipath_unit);
                        dd->pcidev = NULL;
                }

                /*
                 * we check for NULL here, because it's outside the kregbase
                 * check, and we need to call it after the free_irq.  Thus
                 * it's possible that the function pointers were never
                 * initialized.
                 */
                if (dd->ipath_f_cleanup)
                        /* clean up chip-specific stuff */
                        dd->ipath_f_cleanup(dd);

                spin_lock_irqsave(&ipath_devs_lock, flags);
        }

        spin_unlock_irqrestore(&ipath_devs_lock, flags);

        ipath_cdbg(VERBOSE, "Unregistering pci driver\n");
        pci_unregister_driver(&ipath_driver);

        idr_destroy(&unit_table);
}

/**
 * ipath_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 ports are open that use chip resources
 */
int ipath_reset_device(int unit)
{
        int ret, i;
        struct ipath_devdata *dd = ipath_lookup(unit);

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

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

        if (!dd->ipath_kregbase || !(dd->ipath_flags & IPATH_PRESENT)) {
                dev_info(&dd->pcidev->dev, "Invalid unit number %u or "
                         "not initialized or not present\n", unit);
                ret = -ENXIO;
                goto bail;
        }

        if (dd->ipath_pd)
                for (i = 1; i < dd->ipath_portcnt; i++) {
                        if (dd->ipath_pd[i] && dd->ipath_pd[i]->port_cnt) {
                                ipath_dbg("unit %u port %d is in use "
                                          "(PID %u cmd %s), can't reset\n",
                                          unit, i,
                                          dd->ipath_pd[i]->port_pid,
                                          dd->ipath_pd[i]->port_comm);
                                ret = -EBUSY;
                                goto bail;
                        }
                }

        dd->ipath_flags &= ~IPATH_INITTED;
        ret = dd->ipath_f_reset(dd);
        if (ret != 1)
                ipath_dbg("reset was not successful\n");
        ipath_dbg("Trying to reinitialize unit %u after reset attempt\n",
                  unit);
        ret = ipath_init_chip(dd, 1);
        if (ret)
                ipath_dev_err(dd, "Reinitialize unit %u after "
                              "reset failed with %d\n", unit, ret);
        else
                dev_info(&dd->pcidev->dev, "Reinitialized unit %u after "
                         "resetting\n", unit);

bail:
        return ret;
}

module_init(infinipath_init);
module_exit(infinipath_cleanup);