path: root/drivers/infiniband/hw/ipath/ipath_driver.c

/*
 * Copyright (c) 2006 QLogic, Inc. 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/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 "QLogic " 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("QLogic <support@pathscale.com>");
MODULE_DESCRIPTION("QLogic 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) },
	{ 0, }
};

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,
};


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);
	}
	vfree(dd);
}

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

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

	dd = vmalloc(sizeof(*dd));
	if (!dd) {
		dd = ERR_PTR(-ENOMEM);
		goto bail;
	}
	memset(dd, 0, sizeof(*dd));
	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;
}

/*
 * 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;

	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;
	}

	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) {
		/*
		 * if the 64 bit setup fails, try 32 bit.  Some systems
		 * do not setup 64 bit maps on systems with 2GB or less
		 * memory installed.
		 */
		ret = pci_set_dma_mask(pdev, DMA_32BIT_MASK);
		if (ret) {
			dev_info(&pdev->dev,
				"Unable to set DMA mask for unit %u: %d\n",
				dd->ipath_unit, ret);
			goto bail_regions;
		}
		else {
			ipath_dbg("No 64bit DMA mask, used 32 bit mask\n");
			ret = pci_set_consistent_dma_mask(pdev, DMA_32BIT_MASK);
			if (ret)
				dev_info(&pdev->dev,
					"Unable to set DMA consistent mask "
					"for unit %u: %d\n",
					dd->ipath_unit, ret);

		}
	}
	else {
		ret = pci_set_consistent_dma_mask(pdev, DMA_64BIT_MASK);
		if (ret)
			dev_info(&pdev->dev,
				"Unable to set DMA consistent mask "
				"for unit %u: %d\n",
				dd->ipath_unit, ret);
	}

	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 QLogic 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 %llx, end %llx, len %llx\n",
			   j, (unsigned long long)pdev->resource[j].start,
			   (unsigned long long)pdev->resource[j].end,
			   (unsigned long long)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 */
	ipath_cdbg(VERBOSE, "mapped io addr %llx to kregbase %p\n",
		   addr, dd->ipath_kregbase);

	/*
	 * 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_diag_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:
	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_remove(dd);
	ipath_diag_remove(dd);
	ipath_user_remove(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);
}

/* 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, updegr=0, reloop=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;

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

reloop:
	/* read only once at start for performance */
	hdrqtail = (u32)le64_to_cpu(*dd->ipath_hdrqtailptr);

	for (i = 0; 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;
		if (etype != RCVHQ_RCV_TYPE_EXPECTED)
		    updegr = 1;
		/*
		 * update head regs on last packet, and every 16 packets.
		 * Reduce bus traffic, while still trying to prevent
		 * rcvhdrq overflows, for when the queue is nearly full
		 */
		if (l == hdrqtail || (i && !(i&0xf))) {
			u64 lval;
			if (l == hdrqtail) /* PE-800 interrupt only on last */
				lval = dd->ipath_rhdrhead_intr_off | l;
			else
				lval = l;
			(void)ipath_write_ureg(dd, ur_rcvhdrhead, lval, 0);
			if (updegr) {
				(void)ipath_write_ureg(dd, ur_rcvegrindexhead,
						       etail, 0);
				updegr = 0;
			}
		}
	}

	if (!dd->ipath_rhdrhead_intr_off && !reloop) {
		/* HT-400 workaround; we can have a race clearing chip
		 * interrupt with another interrupt about to be delivered,
		 * and can clear it before it is delivered on the GPIO
		 * workaround.  By doing the extra check here for the
		 * in-memory tail register updating while we were doing
		 * earlier packets, we "almost" guarantee we have covered
		 * that case.
		 */
		u32 hqtail = (u32)le64_to_cpu(*dd->ipath_hdrqtailptr);
		if (hqtail != hdrqtail) {
			hdrqtail = hqtail;
			reloop = 1; /* loop 1 extra time at most */
			goto reloop;
		}
	}

	pkttot += i;

	dd->ipath_port0head = l;

	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 contiguous memory (from an i/o perspective), and must be
 * DMA'able (which means for some systems, it will go through an IOMMU,
 * or be forced into a low address range).
 */
int ipath_create_rcvhdrq(struct ipath_devdata *dd,
			 struct ipath_portdata *pd)
{
	int ret = 0;

	if (!pd->port_rcvhdrq) {
		dma_addr_t phys_hdrqtail;
		gfp_t gfp_flags = GFP_USER | __GFP_COMP;
		int amt = ALIGN(dd->ipath_rcvhdrcnt * dd->ipath_rcvhdrentsize *
				sizeof(u32), PAGE_SIZE);

		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_rcvhdrtail_kvaddr = dma_alloc_coherent(
			&dd->pcidev->dev, PAGE_SIZE, &phys_hdrqtail, GFP_KERNEL);
		if (!pd->port_rcvhdrtail_kvaddr) {
			ipath_dev_err(dd, "attempt to allocate 1 page "
				      "for port %u rcvhdrqtailaddr failed\n",
				      pd->port_port);
			ret = -ENOMEM;
			goto bail;
		}
		pd->port_rcvhdrqtailaddr_phys = phys_hdrqtail;

		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);

		ipath_cdbg(VERBOSE, "port %d hdrtailaddr, %llx physical\n",
			   pd->port_port,
			   (unsigned long long) phys_hdrqtail);
	}
	else
		ipath_cdbg(VERBOSE, "reuse port %d rcvhdrq @%p %llx phys; "
			   "hdrtailaddr@%p %llx physical\n",
			   pd->port_port, pd->port_rcvhdrq,
			   pd->port_rcvhdrq_phys, pd->port_rcvhdrtail_kvaddr,
			   (unsigned long long)pd->port_rcvhdrqtailaddr_phys);

	/* clear for security and sanity on each use */
	memset(pd->port_rcvhdrq, 0, pd->port_rcvhdrq_size);
	memset((void *)pd->port_rcvhdrtail_kvaddr, 0, PAGE_SIZE);

	/*
	 * tell chip each time we init it, even if we are re-using previous
	 * memory (we zero the register at process close)
	 */
	ipath_write_kreg_port(dd, dd->ipath_kregs->kr_rcvhdrtailaddr,
			      pd->port_port, pd->port_rcvhdrqtailaddr_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"
	};
	int linkcmd = (which >> INFINIPATH_IBCC_LINKCMD_SHIFT) &
			INFINIPATH_IBCC_LINKCMD_MASK;

	ipath_cdbg(SMA, "Trying to move unit %u to %s, current ltstate "
		   "is %s\n", dd->ipath_unit,
		   what[linkcmd],
		   ipath_ibcstatus_str[
			   (ipath_read_kreg64
			    (dd, dd->ipath_kregs->kr_ibcstatus) >>
			    INFINIPATH_IBCS_LINKTRAININGSTATE_SHIFT) &
			   INFINIPATH_IBCS_LINKTRAININGSTATE_MASK]);
	/* flush all queued sends when going to DOWN or INIT, to be sure that
	 * they don't block SMA and other MAD packets */
	if (!linkcmd || linkcmd == INFINIPATH_IBCC_LINKCMD_INIT) {
		ipath_write_kreg(dd, dd->ipath_kregs->kr_sendctrl,
				 INFINIPATH_S_ABORT);
		ipath_disarm_piobufs(dd, dd->ipath_lastport_piobuf,
		                    (unsigned)(dd->ipath_piobcnt2k +
				    dd->ipath_piobcnt4k) -
				    dd->ipath_lastport_piobuf);
	}

	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 | INFINIPATH_C_FREEZEMODE);

	/*
	 * 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
 * @pd: the portdata structure
 *
 * free up any allocated data for a port
 * This should not touch anything that would affect a simultaneous
 * re-allocation of port data, because it is called after ipath_mutex
 * is released (and can be called from reinit as well).
 * It should never change any chip state, or global driver state.
 * (The only exception to global state is freeing the port0 port0_skbs.)
 */
void ipath_free_pddata(struct ipath_devdata *dd, struct ipath_portdata *pd)
{
	if (!pd)
		return;

	if (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 (pd->port_rcvhdrtail_kvaddr) {
			dma_free_coherent(&dd->pcidev->dev, PAGE_SIZE,
					 (void *)pd->port_rcvhdrtail_kvaddr,
					 pd->port_rcvhdrqtailaddr_phys);
			pd->port_rcvhdrtail_kvaddr = NULL;
		}
	}
	if (pd->port_port && 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 (pd->port_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);
	}
	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_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; we do for portcnt, not cfgports, because cfgports
	 * could have changed while we were loaded.
	 */
	for (port = 0; port < dd->ipath_portcnt; port++) {
		struct ipath_portdata *pd = dd->ipath_pd[port];
		dd->ipath_pd[port] = NULL;
		ipath_free_pddata(dd, pd);
	}
	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);

			/*
			 * 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);

			dd->pcidev = NULL;
		}
		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_cfgports; 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);