drivers/infiniband/hw/ipath/ipath_diag.c - linux - Git at Google

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

 /*
  * This file contains support for diagnostic functions.  It is accessed by
  * opening the ipath_diag device, normally minor number 129.  Diagnostic use
  * of the InfiniPath chip may render the chip or board unusable until the
  * driver is unloaded, or in some cases, until the system is rebooted.
  *
  * Accesses to the chip through this interface are not similar to going
  * through the /sys/bus/pci resource mmap interface.
  */

 #include <linux/io.h>
 #include <linux/pci.h>
 #include <linux/vmalloc.h>
 #include <linux/fs.h>
 #include <asm/uaccess.h>

 #include "ipath_kernel.h"
 #include "ipath_common.h"

 int ipath_diag_inuse;
 static int diag_set_link;

 static int ipath_diag_open(struct inode *in, struct file *fp);
 static int ipath_diag_release(struct inode *in, struct file *fp);
 static ssize_t ipath_diag_read(struct file *fp, char __user *data,
 			       size_t count, loff_t *off);
 static ssize_t ipath_diag_write(struct file *fp, const char __user *data,
 				size_t count, loff_t *off);

 static const struct file_operations diag_file_ops = {
 	.owner = THIS_MODULE,
 	.write = ipath_diag_write,
 	.read = ipath_diag_read,
 	.open = ipath_diag_open,
 	.release = ipath_diag_release
 };

 static ssize_t ipath_diagpkt_write(struct file *fp,
 				   const char __user *data,
 				   size_t count, loff_t *off);

 static const struct file_operations diagpkt_file_ops = {
 	.owner = THIS_MODULE,
 	.write = ipath_diagpkt_write,
 };

 static atomic_t diagpkt_count = ATOMIC_INIT(0);
 static struct cdev *diagpkt_cdev;
 static struct class_device *diagpkt_class_dev;

 int ipath_diag_add(struct ipath_devdata *dd)
 {
 	char name[16];
 	int ret = 0;

 	if (atomic_inc_return(&diagpkt_count) == 1) {
 		ret = ipath_cdev_init(IPATH_DIAGPKT_MINOR,
 				      "ipath_diagpkt", &diagpkt_file_ops,
 				      &diagpkt_cdev, &diagpkt_class_dev);

 		if (ret) {
 			ipath_dev_err(dd, "Couldn't create ipath_diagpkt "
 				      "device: %d", ret);
 			goto done;
 		}
 	}

 	snprintf(name, sizeof(name), "ipath_diag%d", dd->ipath_unit);

 	ret = ipath_cdev_init(IPATH_DIAG_MINOR_BASE + dd->ipath_unit, name,
 			      &diag_file_ops, &dd->diag_cdev,
 			      &dd->diag_class_dev);
 	if (ret)
 		ipath_dev_err(dd, "Couldn't create %s device: %d",
 			      name, ret);

 done:
 	return ret;
 }

 void ipath_diag_remove(struct ipath_devdata *dd)
 {
 	if (atomic_dec_and_test(&diagpkt_count))
 		ipath_cdev_cleanup(&diagpkt_cdev, &diagpkt_class_dev);

 	ipath_cdev_cleanup(&dd->diag_cdev, &dd->diag_class_dev);
 }

 /**
  * ipath_read_umem64 - read a 64-bit quantity from the chip into user space
  * @dd: the infinipath device
  * @uaddr: the location to store the data in user memory
  * @caddr: the source chip address (full pointer, not offset)
  * @count: number of bytes to copy (multiple of 32 bits)
  *
  * This function also localizes all chip memory accesses.
  * The copy should be written such that we read full cacheline packets
  * from the chip.  This is usually used for a single qword
  *
  * NOTE:  This assumes the chip address is 64-bit aligned.
  */
 static int ipath_read_umem64(struct ipath_devdata *dd, void __user *uaddr,
 			     const void __iomem *caddr, size_t count)
 {
 	const u64 __iomem *reg_addr = caddr;
 	const u64 __iomem *reg_end = reg_addr + (count / sizeof(u64));
 	int ret;

 	/* not very efficient, but it works for now */
 	if (reg_addr < dd->ipath_kregbase || reg_end > dd->ipath_kregend) {
 		ret = -EINVAL;
 		goto bail;
 	}
 	while (reg_addr < reg_end) {
 		u64 data = readq(reg_addr);
 		if (copy_to_user(uaddr, &data, sizeof(u64))) {
 			ret = -EFAULT;
 			goto bail;
 		}
 		reg_addr++;
 		uaddr += sizeof(u64);
 	}
 	ret = 0;
 bail:
 	return ret;
 }

 /**
  * ipath_write_umem64 - write a 64-bit quantity to the chip from user space
  * @dd: the infinipath device
  * @caddr: the destination chip address (full pointer, not offset)
  * @uaddr: the source of the data in user memory
  * @count: the number of bytes to copy (multiple of 32 bits)
  *
  * This is usually used for a single qword
  * NOTE:  This assumes the chip address is 64-bit aligned.
  */

 static int ipath_write_umem64(struct ipath_devdata *dd, void __iomem *caddr,
 			      const void __user *uaddr, size_t count)
 {
 	u64 __iomem *reg_addr = caddr;
 	const u64 __iomem *reg_end = reg_addr + (count / sizeof(u64));
 	int ret;

 	/* not very efficient, but it works for now */
 	if (reg_addr < dd->ipath_kregbase || reg_end > dd->ipath_kregend) {
 		ret = -EINVAL;
 		goto bail;
 	}
 	while (reg_addr < reg_end) {
 		u64 data;
 		if (copy_from_user(&data, uaddr, sizeof(data))) {
 			ret = -EFAULT;
 			goto bail;
 		}
 		writeq(data, reg_addr);

 		reg_addr++;
 		uaddr += sizeof(u64);
 	}
 	ret = 0;
 bail:
 	return ret;
 }

 /**
  * ipath_read_umem32 - read a 32-bit quantity from the chip into user space
  * @dd: the infinipath device
  * @uaddr: the location to store the data in user memory
  * @caddr: the source chip address (full pointer, not offset)
  * @count: number of bytes to copy
  *
  * read 32 bit values, not 64 bit; for memories that only
  * support 32 bit reads; usually a single dword.
  */
 static int ipath_read_umem32(struct ipath_devdata *dd, void __user *uaddr,
 			     const void __iomem *caddr, size_t count)
 {
 	const u32 __iomem *reg_addr = caddr;
 	const u32 __iomem *reg_end = reg_addr + (count / sizeof(u32));
 	int ret;

 	if (reg_addr < (u32 __iomem *) dd->ipath_kregbase ||
 	    reg_end > (u32 __iomem *) dd->ipath_kregend) {
 		ret = -EINVAL;
 		goto bail;
 	}
 	/* not very efficient, but it works for now */
 	while (reg_addr < reg_end) {
 		u32 data = readl(reg_addr);
 		if (copy_to_user(uaddr, &data, sizeof(data))) {
 			ret = -EFAULT;
 			goto bail;
 		}

 		reg_addr++;
 		uaddr += sizeof(u32);

 	}
 	ret = 0;
 bail:
 	return ret;
 }

 /**
  * ipath_write_umem32 - write a 32-bit quantity to the chip from user space
  * @dd: the infinipath device
  * @caddr: the destination chip address (full pointer, not offset)
  * @uaddr: the source of the data in user memory
  * @count: number of bytes to copy
  *
  * write 32 bit values, not 64 bit; for memories that only
  * support 32 bit write; usually a single dword.
  */

 static int ipath_write_umem32(struct ipath_devdata *dd, void __iomem *caddr,
 			      const void __user *uaddr, size_t count)
 {
 	u32 __iomem *reg_addr = caddr;
 	const u32 __iomem *reg_end = reg_addr + (count / sizeof(u32));
 	int ret;

 	if (reg_addr < (u32 __iomem *) dd->ipath_kregbase ||
 	    reg_end > (u32 __iomem *) dd->ipath_kregend) {
 		ret = -EINVAL;
 		goto bail;
 	}
 	while (reg_addr < reg_end) {
 		u32 data;
 		if (copy_from_user(&data, uaddr, sizeof(data))) {
 			ret = -EFAULT;
 			goto bail;
 		}
 		writel(data, reg_addr);

 		reg_addr++;
 		uaddr += sizeof(u32);
 	}
 	ret = 0;
 bail:
 	return ret;
 }

 static int ipath_diag_open(struct inode *in, struct file *fp)
 {
 	int unit = iminor(in) - IPATH_DIAG_MINOR_BASE;
 	struct ipath_devdata *dd;
 	int ret;

 	mutex_lock(&ipath_mutex);

 	if (ipath_diag_inuse) {
 		ret = -EBUSY;
 		goto bail;
 	}

 	dd = ipath_lookup(unit);

 	if (dd == NULL || !(dd->ipath_flags & IPATH_PRESENT) ||
 	    !dd->ipath_kregbase) {
 		ret = -ENODEV;
 		goto bail;
 	}

 	fp->private_data = dd;
 	ipath_diag_inuse = -2;
 	diag_set_link = 0;
 	ret = 0;

 	/* Only expose a way to reset the device if we
 	   make it into diag mode. */
 	ipath_expose_reset(&dd->pcidev->dev);

 bail:
 	mutex_unlock(&ipath_mutex);

 	return ret;
 }

 /**
  * ipath_diagpkt_write - write an IB packet
  * @fp: the diag data device file pointer
  * @data: ipath_diag_pkt structure saying where to get the packet
  * @count: size of data to write
  * @off: unused by this code
  */
 static ssize_t ipath_diagpkt_write(struct file *fp,
 				   const char __user *data,
 				   size_t count, loff_t *off)
 {
 	u32 __iomem *piobuf;
 	u32 plen, clen, pbufn;
 	struct ipath_diag_pkt odp;
 	struct ipath_diag_xpkt dp;
 	u32 *tmpbuf = NULL;
 	struct ipath_devdata *dd;
 	ssize_t ret = 0;
 	u64 val;
 	u32 l_state, lt_state; /* LinkState, LinkTrainingState */

 	if (count < sizeof(odp)) {
 		ret = -EINVAL;
 		goto bail;
 	}

 	if (count == sizeof(dp)) {
 		if (copy_from_user(&dp, data, sizeof(dp))) {
 			ret = -EFAULT;
 			goto bail;
 		}
 	} else if (copy_from_user(&odp, data, sizeof(odp))) {
 		ret = -EFAULT;
 		goto bail;
 	}

 	/*
 	 * Due to padding/alignment issues (lessened with new struct)
 	 * the old and new structs are the same length. We need to
 	 * disambiguate them, which we can do because odp.len has never
 	 * been less than the total of LRH+BTH+DETH so far, while
 	 * dp.unit (same offset) unit is unlikely to get that high.
 	 * Similarly, dp.data, the pointer to user at the same offset
 	 * as odp.unit, is almost certainly at least one (512byte)page
 	 * "above" NULL. The if-block below can be omitted if compatibility
 	 * between a new driver and older diagnostic code is unimportant.
 	 * compatibility the other direction (new diags, old driver) is
 	 * handled in the diagnostic code, with a warning.
 	 */
 	if (dp.unit >= 20 && dp.data < 512) {
 		/* very probable version mismatch. Fix it up */
 		memcpy(&odp, &dp, sizeof(odp));
 		/* We got a legacy dp, copy elements to dp */
 		dp.unit = odp.unit;
 		dp.data = odp.data;
 		dp.len = odp.len;
 		dp.pbc_wd = 0; /* Indicate we need to compute PBC wd */
 	}

 	/* send count must be an exact number of dwords */
 	if (dp.len & 3) {
 		ret = -EINVAL;
 		goto bail;
 	}

 	clen = dp.len >> 2;

 	dd = ipath_lookup(dp.unit);
 	if (!dd || !(dd->ipath_flags & IPATH_PRESENT) ||
 	    !dd->ipath_kregbase) {
 		ipath_cdbg(VERBOSE, "illegal unit %u for diag data send\n",
 			   dp.unit);
 		ret = -ENODEV;
 		goto bail;
 	}

 	if (ipath_diag_inuse && !diag_set_link &&
 	    !(dd->ipath_flags & IPATH_LINKACTIVE)) {
 		diag_set_link = 1;
 		ipath_cdbg(VERBOSE, "Trying to set to set link active for "
 			   "diag pkt\n");
 		ipath_set_linkstate(dd, IPATH_IB_LINKARM);
 		ipath_set_linkstate(dd, IPATH_IB_LINKACTIVE);
 	}

 	if (!(dd->ipath_flags & IPATH_INITTED)) {
 		/* no hardware, freeze, etc. */
 		ipath_cdbg(VERBOSE, "unit %u not usable\n", dd->ipath_unit);
 		ret = -ENODEV;
 		goto bail;
 	}
 	/*
 	 * Want to skip check for l_state if using custom PBC,
 	 * because we might be trying to force an SM packet out.
 	 * first-cut, skip _all_ state checking in that case.
 	 */
 	val = ipath_ib_state(dd, dd->ipath_lastibcstat);
 	lt_state = ipath_ib_linktrstate(dd, dd->ipath_lastibcstat);
 	l_state = ipath_ib_linkstate(dd, dd->ipath_lastibcstat);
 	if (!dp.pbc_wd && (lt_state != INFINIPATH_IBCS_LT_STATE_LINKUP ||
 	    (val != dd->ib_init && val != dd->ib_arm &&
 	    val != dd->ib_active))) {
 		ipath_cdbg(VERBOSE, "unit %u not ready (state %llx)\n",
 			   dd->ipath_unit, (unsigned long long) val);
 		ret = -EINVAL;
 		goto bail;
 	}

 	/* need total length before first word written */
 	/* +1 word is for the qword padding */
 	plen = sizeof(u32) + dp.len;

 	if ((plen + 4) > dd->ipath_ibmaxlen) {
 		ipath_dbg("Pkt len 0x%x > ibmaxlen %x\n",
 			  plen - 4, dd->ipath_ibmaxlen);
 		ret = -EINVAL;
 		goto bail;	/* before writing pbc */
 	}
 	tmpbuf = vmalloc(plen);
 	if (!tmpbuf) {
 		dev_info(&dd->pcidev->dev, "Unable to allocate tmp buffer, "
 			 "failing\n");
 		ret = -ENOMEM;
 		goto bail;
 	}

 	if (copy_from_user(tmpbuf,
 			   (const void __user *) (unsigned long) dp.data,
 			   dp.len)) {
 		ret = -EFAULT;
 		goto bail;
 	}

 	plen >>= 2;		/* in dwords */

 	piobuf = ipath_getpiobuf(dd, plen, &pbufn);
 	if (!piobuf) {
 		ipath_cdbg(VERBOSE, "No PIO buffers avail unit for %u\n",
 			   dd->ipath_unit);
 		ret = -EBUSY;
 		goto bail;
 	}
 	/* disarm it just to be extra sure */
 	ipath_disarm_piobufs(dd, pbufn, 1);

 	if (ipath_debug & __IPATH_PKTDBG)
 		ipath_cdbg(VERBOSE, "unit %u 0x%x+1w pio%d\n",
 			   dd->ipath_unit, plen - 1, pbufn);

 	if (dp.pbc_wd == 0)
 		dp.pbc_wd = plen;
 	writeq(dp.pbc_wd, piobuf);
 	/*
 	 * Copy all by the trigger word, then flush, so it's written
 	 * to chip before trigger word, then write trigger word, then
 	 * flush again, so packet is sent.
 	 */
 	if (dd->ipath_flags & IPATH_PIO_FLUSH_WC) {
 		ipath_flush_wc();
 		__iowrite32_copy(piobuf + 2, tmpbuf, clen - 1);
 		ipath_flush_wc();
 		__raw_writel(tmpbuf[clen - 1], piobuf + clen + 1);
 	} else
 		__iowrite32_copy(piobuf + 2, tmpbuf, clen);

 	ipath_flush_wc();

 	ret = sizeof(dp);

 bail:
 	vfree(tmpbuf);
 	return ret;
 }

 static int ipath_diag_release(struct inode *in, struct file *fp)
 {
 	mutex_lock(&ipath_mutex);
 	ipath_diag_inuse = 0;
 	fp->private_data = NULL;
 	mutex_unlock(&ipath_mutex);
 	return 0;
 }

 static ssize_t ipath_diag_read(struct file *fp, char __user *data,
 			       size_t count, loff_t *off)
 {
 	struct ipath_devdata *dd = fp->private_data;
 	void __iomem *kreg_base;
 	ssize_t ret;

 	kreg_base = dd->ipath_kregbase;

 	if (count == 0)
 		ret = 0;
 	else if ((count % 4) || (*off % 4))
 		/* address or length is not 32-bit aligned, hence invalid */
 		ret = -EINVAL;
 	else if (ipath_diag_inuse < 1 && (*off || count != 8))
 		ret = -EINVAL;  /* prevent cat /dev/ipath_diag* */
 	else if ((count % 8) || (*off % 8))
 		/* address or length not 64-bit aligned; do 32-bit reads */
 		ret = ipath_read_umem32(dd, data, kreg_base + *off, count);
 	else
 		ret = ipath_read_umem64(dd, data, kreg_base + *off, count);

 	if (ret >= 0) {
 		*off += count;
 		ret = count;
 		if (ipath_diag_inuse == -2)
 			ipath_diag_inuse++;
 	}

 	return ret;
 }

 static ssize_t ipath_diag_write(struct file *fp, const char __user *data,
 				size_t count, loff_t *off)
 {
 	struct ipath_devdata *dd = fp->private_data;
 	void __iomem *kreg_base;
 	ssize_t ret;

 	kreg_base = dd->ipath_kregbase;

 	if (count == 0)
 		ret = 0;
 	else if ((count % 4) || (*off % 4))
 		/* address or length is not 32-bit aligned, hence invalid */
 		ret = -EINVAL;
 	else if ((ipath_diag_inuse == -1 && (*off || count != 8)) ||
 		 ipath_diag_inuse == -2)  /* read qw off 0, write qw off 0 */
 		ret = -EINVAL;  /* before any other write allowed */
 	else if ((count % 8) || (*off % 8))
 		/* address or length not 64-bit aligned; do 32-bit writes */
 		ret = ipath_write_umem32(dd, kreg_base + *off, data, count);
 	else
 		ret = ipath_write_umem64(dd, kreg_base + *off, data, count);

 	if (ret >= 0) {
 		*off += count;
 		ret = count;
 		if (ipath_diag_inuse == -1)
 			ipath_diag_inuse = 1; /* all read/write OK now */
 	}

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

	/*
	* This file contains support for diagnostic functions. It is accessed by
	* opening the ipath_diag device, normally minor number 129. Diagnostic use
	* of the InfiniPath chip may render the chip or board unusable until the
	* driver is unloaded, or in some cases, until the system is rebooted.
	*
	* Accesses to the chip through this interface are not similar to going
	* through the /sys/bus/pci resource mmap interface.
	*/

	#include <linux/io.h>
	#include <linux/pci.h>
	#include <linux/vmalloc.h>
	#include <linux/fs.h>
	#include <asm/uaccess.h>

	#include "ipath_kernel.h"
	#include "ipath_common.h"

	int ipath_diag_inuse;
	static int diag_set_link;

	static int ipath_diag_open(struct inode in, struct file fp);
	static int ipath_diag_release(struct inode in, struct file fp);
	static ssize_t ipath_diag_read(struct file fp, char __user data,
	size_t count, loff_t *off);
	static ssize_t ipath_diag_write(struct file fp, const char __user data,
	size_t count, loff_t *off);

	static const struct file_operations diag_file_ops = {
	.owner = THIS_MODULE,
	.write = ipath_diag_write,
	.read = ipath_diag_read,
	.open = ipath_diag_open,
	.release = ipath_diag_release
	};

	static ssize_t ipath_diagpkt_write(struct file *fp,
	const char __user *data,
	size_t count, loff_t *off);

	static const struct file_operations diagpkt_file_ops = {
	.owner = THIS_MODULE,
	.write = ipath_diagpkt_write,
	};

	static atomic_t diagpkt_count = ATOMIC_INIT(0);
	static struct cdev *diagpkt_cdev;
	static struct class_device *diagpkt_class_dev;

	int ipath_diag_add(struct ipath_devdata *dd)
	{
	char name[16];
	int ret = 0;

	if (atomic_inc_return(&diagpkt_count) == 1) {
	ret = ipath_cdev_init(IPATH_DIAGPKT_MINOR,
	"ipath_diagpkt", &diagpkt_file_ops,
	&diagpkt_cdev, &diagpkt_class_dev);

	if (ret) {
	ipath_dev_err(dd, "Couldn't create ipath_diagpkt "
	"device: %d", ret);
	goto done;
	}
	}

	snprintf(name, sizeof(name), "ipath_diag%d", dd->ipath_unit);

	ret = ipath_cdev_init(IPATH_DIAG_MINOR_BASE + dd->ipath_unit, name,
	&diag_file_ops, &dd->diag_cdev,
	&dd->diag_class_dev);
	if (ret)
	ipath_dev_err(dd, "Couldn't create %s device: %d",
	name, ret);

	done:
	return ret;
	}

	void ipath_diag_remove(struct ipath_devdata *dd)
	{
	if (atomic_dec_and_test(&diagpkt_count))
	ipath_cdev_cleanup(&diagpkt_cdev, &diagpkt_class_dev);

	ipath_cdev_cleanup(&dd->diag_cdev, &dd->diag_class_dev);
	}

	/**
	* ipath_read_umem64 - read a 64-bit quantity from the chip into user space
	* @dd: the infinipath device
	* @uaddr: the location to store the data in user memory
	* @caddr: the source chip address (full pointer, not offset)
	* @count: number of bytes to copy (multiple of 32 bits)
	*
	* This function also localizes all chip memory accesses.
	* The copy should be written such that we read full cacheline packets
	* from the chip. This is usually used for a single qword
	*
	* NOTE: This assumes the chip address is 64-bit aligned.
	*/
	static int ipath_read_umem64(struct ipath_devdata dd, void __user uaddr,
	const void __iomem *caddr, size_t count)
	{
	const u64 __iomem *reg_addr = caddr;
	const u64 __iomem *reg_end = reg_addr + (count / sizeof(u64));
	int ret;

	/* not very efficient, but it works for now */
	if (reg_addr < dd->ipath_kregbase \|\| reg_end > dd->ipath_kregend) {
	ret = -EINVAL;
	goto bail;
	}
	while (reg_addr < reg_end) {
	u64 data = readq(reg_addr);
	if (copy_to_user(uaddr, &data, sizeof(u64))) {
	ret = -EFAULT;
	goto bail;
	}
	reg_addr++;
	uaddr += sizeof(u64);
	}
	ret = 0;
	bail:
	return ret;
	}

	/**
	* ipath_write_umem64 - write a 64-bit quantity to the chip from user space
	* @dd: the infinipath device
	* @caddr: the destination chip address (full pointer, not offset)
	* @uaddr: the source of the data in user memory
	* @count: the number of bytes to copy (multiple of 32 bits)
	*
	* This is usually used for a single qword
	* NOTE: This assumes the chip address is 64-bit aligned.
	*/

	static int ipath_write_umem64(struct ipath_devdata dd, void __iomem caddr,
	const void __user *uaddr, size_t count)
	{
	u64 __iomem *reg_addr = caddr;
	const u64 __iomem *reg_end = reg_addr + (count / sizeof(u64));
	int ret;

	/* not very efficient, but it works for now */
	if (reg_addr < dd->ipath_kregbase \|\| reg_end > dd->ipath_kregend) {
	ret = -EINVAL;
	goto bail;
	}
	while (reg_addr < reg_end) {
	u64 data;
	if (copy_from_user(&data, uaddr, sizeof(data))) {
	ret = -EFAULT;
	goto bail;
	}
	writeq(data, reg_addr);

	reg_addr++;
	uaddr += sizeof(u64);
	}
	ret = 0;
	bail:
	return ret;
	}

	/**
	* ipath_read_umem32 - read a 32-bit quantity from the chip into user space
	* @dd: the infinipath device
	* @uaddr: the location to store the data in user memory
	* @caddr: the source chip address (full pointer, not offset)
	* @count: number of bytes to copy
	*
	* read 32 bit values, not 64 bit; for memories that only
	* support 32 bit reads; usually a single dword.
	*/
	static int ipath_read_umem32(struct ipath_devdata dd, void __user uaddr,
	const void __iomem *caddr, size_t count)
	{
	const u32 __iomem *reg_addr = caddr;
	const u32 __iomem *reg_end = reg_addr + (count / sizeof(u32));
	int ret;

	if (reg_addr < (u32 __iomem *) dd->ipath_kregbase \|\|
	reg_end > (u32 __iomem *) dd->ipath_kregend) {
	ret = -EINVAL;
	goto bail;
	}
	/* not very efficient, but it works for now */
	while (reg_addr < reg_end) {
	u32 data = readl(reg_addr);
	if (copy_to_user(uaddr, &data, sizeof(data))) {
	ret = -EFAULT;
	goto bail;
	}

	reg_addr++;
	uaddr += sizeof(u32);

	}
	ret = 0;
	bail:
	return ret;
	}

	/**
	* ipath_write_umem32 - write a 32-bit quantity to the chip from user space
	* @dd: the infinipath device
	* @caddr: the destination chip address (full pointer, not offset)
	* @uaddr: the source of the data in user memory
	* @count: number of bytes to copy
	*
	* write 32 bit values, not 64 bit; for memories that only
	* support 32 bit write; usually a single dword.
	*/

	static int ipath_write_umem32(struct ipath_devdata dd, void __iomem caddr,
	const void __user *uaddr, size_t count)
	{
	u32 __iomem *reg_addr = caddr;
	const u32 __iomem *reg_end = reg_addr + (count / sizeof(u32));
	int ret;

	if (reg_addr < (u32 __iomem *) dd->ipath_kregbase \|\|
	reg_end > (u32 __iomem *) dd->ipath_kregend) {
	ret = -EINVAL;
	goto bail;
	}
	while (reg_addr < reg_end) {
	u32 data;
	if (copy_from_user(&data, uaddr, sizeof(data))) {
	ret = -EFAULT;
	goto bail;
	}
	writel(data, reg_addr);

	reg_addr++;
	uaddr += sizeof(u32);
	}
	ret = 0;
	bail:
	return ret;
	}

	static int ipath_diag_open(struct inode in, struct file fp)
	{
	int unit = iminor(in) - IPATH_DIAG_MINOR_BASE;
	struct ipath_devdata *dd;
	int ret;

	mutex_lock(&ipath_mutex);

	if (ipath_diag_inuse) {
	ret = -EBUSY;
	goto bail;
	}

	dd = ipath_lookup(unit);

	if (dd == NULL \|\| !(dd->ipath_flags & IPATH_PRESENT) \|\|
	!dd->ipath_kregbase) {
	ret = -ENODEV;
	goto bail;
	}

	fp->private_data = dd;
	ipath_diag_inuse = -2;
	diag_set_link = 0;
	ret = 0;

	/* Only expose a way to reset the device if we
	make it into diag mode. */
	ipath_expose_reset(&dd->pcidev->dev);

	bail:
	mutex_unlock(&ipath_mutex);

	return ret;
	}

	/**
	* ipath_diagpkt_write - write an IB packet
	* @fp: the diag data device file pointer
	* @data: ipath_diag_pkt structure saying where to get the packet
	* @count: size of data to write
	* @off: unused by this code
	*/
	static ssize_t ipath_diagpkt_write(struct file *fp,
	const char __user *data,
	size_t count, loff_t *off)
	{
	u32 __iomem *piobuf;
	u32 plen, clen, pbufn;
	struct ipath_diag_pkt odp;
	struct ipath_diag_xpkt dp;
	u32 *tmpbuf = NULL;
	struct ipath_devdata *dd;
	ssize_t ret = 0;
	u64 val;
	u32 l_state, lt_state; /* LinkState, LinkTrainingState */

	if (count < sizeof(odp)) {
	ret = -EINVAL;
	goto bail;
	}

	if (count == sizeof(dp)) {
	if (copy_from_user(&dp, data, sizeof(dp))) {
	ret = -EFAULT;
	goto bail;
	}
	} else if (copy_from_user(&odp, data, sizeof(odp))) {
	ret = -EFAULT;
	goto bail;
	}

	/*
	* Due to padding/alignment issues (lessened with new struct)
	* the old and new structs are the same length. We need to
	* disambiguate them, which we can do because odp.len has never
	* been less than the total of LRH+BTH+DETH so far, while
	* dp.unit (same offset) unit is unlikely to get that high.
	* Similarly, dp.data, the pointer to user at the same offset
	* as odp.unit, is almost certainly at least one (512byte)page
	* "above" NULL. The if-block below can be omitted if compatibility
	* between a new driver and older diagnostic code is unimportant.
	* compatibility the other direction (new diags, old driver) is
	* handled in the diagnostic code, with a warning.
	*/
	if (dp.unit >= 20 && dp.data < 512) {
	/* very probable version mismatch. Fix it up */
	memcpy(&odp, &dp, sizeof(odp));
	/* We got a legacy dp, copy elements to dp */
	dp.unit = odp.unit;
	dp.data = odp.data;
	dp.len = odp.len;
	dp.pbc_wd = 0; /* Indicate we need to compute PBC wd */
	}

	/* send count must be an exact number of dwords */
	if (dp.len & 3) {
	ret = -EINVAL;
	goto bail;
	}

	clen = dp.len >> 2;

	dd = ipath_lookup(dp.unit);
	if (!dd \|\| !(dd->ipath_flags & IPATH_PRESENT) \|\|
	!dd->ipath_kregbase) {
	ipath_cdbg(VERBOSE, "illegal unit %u for diag data send\n",
	dp.unit);
	ret = -ENODEV;
	goto bail;
	}

	if (ipath_diag_inuse && !diag_set_link &&
	!(dd->ipath_flags & IPATH_LINKACTIVE)) {
	diag_set_link = 1;
	ipath_cdbg(VERBOSE, "Trying to set to set link active for "
	"diag pkt\n");
	ipath_set_linkstate(dd, IPATH_IB_LINKARM);
	ipath_set_linkstate(dd, IPATH_IB_LINKACTIVE);
	}

	if (!(dd->ipath_flags & IPATH_INITTED)) {
	/* no hardware, freeze, etc. */
	ipath_cdbg(VERBOSE, "unit %u not usable\n", dd->ipath_unit);
	ret = -ENODEV;
	goto bail;
	}
	/*
	* Want to skip check for l_state if using custom PBC,
	* because we might be trying to force an SM packet out.
	* first-cut, skip _all_ state checking in that case.
	*/
	val = ipath_ib_state(dd, dd->ipath_lastibcstat);
	lt_state = ipath_ib_linktrstate(dd, dd->ipath_lastibcstat);
	l_state = ipath_ib_linkstate(dd, dd->ipath_lastibcstat);
	if (!dp.pbc_wd && (lt_state != INFINIPATH_IBCS_LT_STATE_LINKUP \|\|
	(val != dd->ib_init && val != dd->ib_arm &&
	val != dd->ib_active))) {
	ipath_cdbg(VERBOSE, "unit %u not ready (state %llx)\n",
	dd->ipath_unit, (unsigned long long) val);
	ret = -EINVAL;
	goto bail;
	}

	/* need total length before first word written */
	/* +1 word is for the qword padding */
	plen = sizeof(u32) + dp.len;

	if ((plen + 4) > dd->ipath_ibmaxlen) {
	ipath_dbg("Pkt len 0x%x > ibmaxlen %x\n",
	plen - 4, dd->ipath_ibmaxlen);
	ret = -EINVAL;
	goto bail; /* before writing pbc */
	}
	tmpbuf = vmalloc(plen);
	if (!tmpbuf) {
	dev_info(&dd->pcidev->dev, "Unable to allocate tmp buffer, "
	"failing\n");
	ret = -ENOMEM;
	goto bail;
	}

	if (copy_from_user(tmpbuf,
	(const void __user *) (unsigned long) dp.data,
	dp.len)) {
	ret = -EFAULT;
	goto bail;
	}

	plen >>= 2; /* in dwords */

	piobuf = ipath_getpiobuf(dd, plen, &pbufn);
	if (!piobuf) {
	ipath_cdbg(VERBOSE, "No PIO buffers avail unit for %u\n",
	dd->ipath_unit);
	ret = -EBUSY;
	goto bail;
	}
	/* disarm it just to be extra sure */
	ipath_disarm_piobufs(dd, pbufn, 1);

	if (ipath_debug & __IPATH_PKTDBG)
	ipath_cdbg(VERBOSE, "unit %u 0x%x+1w pio%d\n",
	dd->ipath_unit, plen - 1, pbufn);

	if (dp.pbc_wd == 0)
	dp.pbc_wd = plen;
	writeq(dp.pbc_wd, piobuf);
	/*
	* Copy all by the trigger word, then flush, so it's written
	* to chip before trigger word, then write trigger word, then
	* flush again, so packet is sent.
	*/
	if (dd->ipath_flags & IPATH_PIO_FLUSH_WC) {
	ipath_flush_wc();
	__iowrite32_copy(piobuf + 2, tmpbuf, clen - 1);
	ipath_flush_wc();
	__raw_writel(tmpbuf[clen - 1], piobuf + clen + 1);
	} else
	__iowrite32_copy(piobuf + 2, tmpbuf, clen);

	ipath_flush_wc();

	ret = sizeof(dp);

	bail:
	vfree(tmpbuf);
	return ret;
	}

	static int ipath_diag_release(struct inode in, struct file fp)
	{
	mutex_lock(&ipath_mutex);
	ipath_diag_inuse = 0;
	fp->private_data = NULL;
	mutex_unlock(&ipath_mutex);
	return 0;
	}

	static ssize_t ipath_diag_read(struct file fp, char __user data,
	size_t count, loff_t *off)
	{
	struct ipath_devdata *dd = fp->private_data;
	void __iomem *kreg_base;
	ssize_t ret;

	kreg_base = dd->ipath_kregbase;

	if (count == 0)
	ret = 0;
	else if ((count % 4) \|\| (*off % 4))
	/* address or length is not 32-bit aligned, hence invalid */
	ret = -EINVAL;
	else if (ipath_diag_inuse < 1 && (*off \|\| count != 8))
	ret = -EINVAL; /* prevent cat /dev/ipath_diag* */
	else if ((count % 8) \|\| (*off % 8))
	/* address or length not 64-bit aligned; do 32-bit reads */
	ret = ipath_read_umem32(dd, data, kreg_base + *off, count);
	else
	ret = ipath_read_umem64(dd, data, kreg_base + *off, count);

	if (ret >= 0) {
	*off += count;
	ret = count;
	if (ipath_diag_inuse == -2)
	ipath_diag_inuse++;
	}

	return ret;
	}

	static ssize_t ipath_diag_write(struct file fp, const char __user data,
	size_t count, loff_t *off)
	{
	struct ipath_devdata *dd = fp->private_data;
	void __iomem *kreg_base;
	ssize_t ret;

	kreg_base = dd->ipath_kregbase;

	if (count == 0)
	ret = 0;
	else if ((count % 4) \|\| (*off % 4))
	/* address or length is not 32-bit aligned, hence invalid */
	ret = -EINVAL;
	else if ((ipath_diag_inuse == -1 && (*off \|\| count != 8)) \|\|
	ipath_diag_inuse == -2) /* read qw off 0, write qw off 0 */
	ret = -EINVAL; /* before any other write allowed */
	else if ((count % 8) \|\| (*off % 8))
	/* address or length not 64-bit aligned; do 32-bit writes */
	ret = ipath_write_umem32(dd, kreg_base + *off, data, count);
	else
	ret = ipath_write_umem64(dd, kreg_base + *off, data, count);

	if (ret >= 0) {
	*off += count;
	ret = count;
	if (ipath_diag_inuse == -1)
	ipath_diag_inuse = 1; /* all read/write OK now */
	}

	return ret;
	}