IB/ipath: support for userspace apps using core driver

These files introduce a char device that userspace apps use to gain
direct memory-mapped access to the InfiniPath hardware, and routines for
pinning and unpinning user memory in cases where the hardware needs to
DMA into the user address space.

Signed-off-by: Bryan O'Sullivan <bos@pathscale.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

drivers/infiniband/hw/ipath/ipath_file_ops.c

@@ -0,0 +1,1910 @@
+/*
+ * 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/pci.h>
+#include <linux/poll.h>
+#include <linux/cdev.h>
+#include <linux/swap.h>
+#include <linux/vmalloc.h>
+#include <asm/pgtable.h>
+
+#include "ipath_kernel.h"
+#include "ips_common.h"
+#include "ipath_layer.h"
+
+static int ipath_open(struct inode *, struct file *);
+static int ipath_close(struct inode *, struct file *);
+static ssize_t ipath_write(struct file *, const char __user *, size_t,
+			   loff_t *);
+static unsigned int ipath_poll(struct file *, struct poll_table_struct *);
+static int ipath_mmap(struct file *, struct vm_area_struct *);
+
+static struct file_operations ipath_file_ops = {
+	.owner = THIS_MODULE,
+	.write = ipath_write,
+	.open = ipath_open,
+	.release = ipath_close,
+	.poll = ipath_poll,
+	.mmap = ipath_mmap
+};
+
+static int ipath_get_base_info(struct ipath_portdata *pd,
+			       void __user *ubase, size_t ubase_size)
+{
+	int ret = 0;
+	struct ipath_base_info *kinfo = NULL;
+	struct ipath_devdata *dd = pd->port_dd;
+
+	if (ubase_size < sizeof(*kinfo)) {
+		ipath_cdbg(PROC,
+			   "Base size %lu, need %lu (version mismatch?)\n",
+			   (unsigned long) ubase_size,
+			   (unsigned long) sizeof(*kinfo));
+		ret = -EINVAL;
+		goto bail;
+	}
+
+	kinfo = kzalloc(sizeof(*kinfo), GFP_KERNEL);
+	if (kinfo == NULL) {
+		ret = -ENOMEM;
+		goto bail;
+	}
+
+	ret = dd->ipath_f_get_base_info(pd, kinfo);
+	if (ret < 0)
+		goto bail;
+
+	kinfo->spi_rcvhdr_cnt = dd->ipath_rcvhdrcnt;
+	kinfo->spi_rcvhdrent_size = dd->ipath_rcvhdrentsize;
+	kinfo->spi_tidegrcnt = dd->ipath_rcvegrcnt;
+	kinfo->spi_rcv_egrbufsize = dd->ipath_rcvegrbufsize;
+	/*
+	 * have to mmap whole thing
+	 */
+	kinfo->spi_rcv_egrbuftotlen =
+		pd->port_rcvegrbuf_chunks * pd->port_rcvegrbuf_size;
+	kinfo->spi_rcv_egrperchunk = pd->port_rcvegrbufs_perchunk;
+	kinfo->spi_rcv_egrchunksize = kinfo->spi_rcv_egrbuftotlen /
+		pd->port_rcvegrbuf_chunks;
+	kinfo->spi_tidcnt = dd->ipath_rcvtidcnt;
+	/*
+	 * for this use, may be ipath_cfgports summed over all chips that
+	 * are are configured and present
+	 */
+	kinfo->spi_nports = dd->ipath_cfgports;
+	/* unit (chip/board) our port is on */
+	kinfo->spi_unit = dd->ipath_unit;
+	/* for now, only a single page */
+	kinfo->spi_tid_maxsize = PAGE_SIZE;
+
+	/*
+	 * Doing this per port, and based on the skip value, etc.  This has
+	 * to be the actual buffer size, since the protocol code treats it
+	 * as an array.
+	 *
+	 * These have to be set to user addresses in the user code via mmap.
+	 * These values are used on return to user code for the mmap target
+	 * addresses only.  For 32 bit, same 44 bit address problem, so use
+	 * the physical address, not virtual.  Before 2.6.11, using the
+	 * page_address() macro worked, but in 2.6.11, even that returns the
+	 * full 64 bit address (upper bits all 1's).  So far, using the
+	 * physical addresses (or chip offsets, for chip mapping) works, but
+	 * no doubt some future kernel release will chang that, and we'll be
+	 * on to yet another method of dealing with this
+	 */
+	kinfo->spi_rcvhdr_base = (u64) pd->port_rcvhdrq_phys;
+	kinfo->spi_rcv_egrbufs = (u64) pd->port_rcvegr_phys;
+	kinfo->spi_pioavailaddr = (u64) dd->ipath_pioavailregs_phys;
+	kinfo->spi_status = (u64) kinfo->spi_pioavailaddr +
+		(void *) dd->ipath_statusp -
+		(void *) dd->ipath_pioavailregs_dma;
+	kinfo->spi_piobufbase = (u64) pd->port_piobufs;
+	kinfo->__spi_uregbase =
+		dd->ipath_uregbase + dd->ipath_palign * pd->port_port;
+
+	kinfo->spi_pioindex = dd->ipath_pbufsport * (pd->port_port - 1);
+	kinfo->spi_piocnt = dd->ipath_pbufsport;
+	kinfo->spi_pioalign = dd->ipath_palign;
+
+	kinfo->spi_qpair = IPATH_KD_QP;
+	kinfo->spi_piosize = dd->ipath_ibmaxlen;
+	kinfo->spi_mtu = dd->ipath_ibmaxlen;	/* maxlen, not ibmtu */
+	kinfo->spi_port = pd->port_port;
+	kinfo->spi_sw_version = IPATH_USER_SWVERSION;
+	kinfo->spi_hw_version = dd->ipath_revision;
+
+	if (copy_to_user(ubase, kinfo, sizeof(*kinfo)))
+		ret = -EFAULT;
+
+bail:
+	kfree(kinfo);
+	return ret;
+}
+
+/**
+ * ipath_tid_update - update a port TID
+ * @pd: the port
+ * @ti: the TID information
+ *
+ * The new implementation as of Oct 2004 is that the driver assigns
+ * the tid and returns it to the caller.   To make it easier to
+ * catch bugs, and to reduce search time, we keep a cursor for
+ * each port, walking the shadow tid array to find one that's not
+ * in use.
+ *
+ * For now, if we can't allocate the full list, we fail, although
+ * in the long run, we'll allocate as many as we can, and the
+ * caller will deal with that by trying the remaining pages later.
+ * That means that when we fail, we have to mark the tids as not in
+ * use again, in our shadow copy.
+ *
+ * It's up to the caller to free the tids when they are done.
+ * We'll unlock the pages as they free them.
+ *
+ * Also, right now we are locking one page at a time, but since
+ * the intended use of this routine is for a single group of
+ * virtually contiguous pages, that should change to improve
+ * performance.
+ */
+static int ipath_tid_update(struct ipath_portdata *pd,
+			    const struct ipath_tid_info *ti)
+{
+	int ret = 0, ntids;
+	u32 tid, porttid, cnt, i, tidcnt;
+	u16 *tidlist;
+	struct ipath_devdata *dd = pd->port_dd;
+	u64 physaddr;
+	unsigned long vaddr;
+	u64 __iomem *tidbase;
+	unsigned long tidmap[8];
+	struct page **pagep = NULL;
+
+	if (!dd->ipath_pageshadow) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	cnt = ti->tidcnt;
+	if (!cnt) {
+		ipath_dbg("After copyin, tidcnt 0, tidlist %llx\n",
+			  (unsigned long long) ti->tidlist);
+		/*
+		 * Should we treat as success?  likely a bug
+		 */
+		ret = -EFAULT;
+		goto done;
+	}
+	tidcnt = dd->ipath_rcvtidcnt;
+	if (cnt >= tidcnt) {
+		/* make sure it all fits in port_tid_pg_list */
+		dev_info(&dd->pcidev->dev, "Process tried to allocate %u "
+			 "TIDs, only trying max (%u)\n", cnt, tidcnt);
+		cnt = tidcnt;
+	}
+	pagep = (struct page **)pd->port_tid_pg_list;
+	tidlist = (u16 *) (&pagep[cnt]);
+
+	memset(tidmap, 0, sizeof(tidmap));
+	tid = pd->port_tidcursor;
+	/* before decrement; chip actual # */
+	porttid = pd->port_port * tidcnt;
+	ntids = tidcnt;
+	tidbase = (u64 __iomem *) (((char __iomem *) dd->ipath_kregbase) +
+				   dd->ipath_rcvtidbase +
+				   porttid * sizeof(*tidbase));
+
+	ipath_cdbg(VERBOSE, "Port%u %u tids, cursor %u, tidbase %p\n",
+		   pd->port_port, cnt, tid, tidbase);
+
+	/* virtual address of first page in transfer */
+	vaddr = ti->tidvaddr;
+	if (!access_ok(VERIFY_WRITE, (void __user *) vaddr,
+		       cnt * PAGE_SIZE)) {
+		ipath_dbg("Fail vaddr %p, %u pages, !access_ok\n",
+			  (void *)vaddr, cnt);
+		ret = -EFAULT;
+		goto done;
+	}
+	ret = ipath_get_user_pages(vaddr, cnt, pagep);
+	if (ret) {
+		if (ret == -EBUSY) {
+			ipath_dbg("Failed to lock addr %p, %u pages "
+				  "(already locked)\n",
+				  (void *) vaddr, cnt);
+			/*
+			 * for now, continue, and see what happens but with
+			 * the new implementation, this should never happen,
+			 * unless perhaps the user has mpin'ed the pages
+			 * themselves (something we need to test)
+			 */
+			ret = 0;
+		} else {
+			dev_info(&dd->pcidev->dev,
+				 "Failed to lock addr %p, %u pages: "
+				 "errno %d\n", (void *) vaddr, cnt, -ret);
+			goto done;
+		}
+	}
+	for (i = 0; i < cnt; i++, vaddr += PAGE_SIZE) {
+		for (; ntids--; tid++) {
+			if (tid == tidcnt)
+				tid = 0;
+			if (!dd->ipath_pageshadow[porttid + tid])
+				break;
+		}
+		if (ntids < 0) {
+			/*
+			 * oops, wrapped all the way through their TIDs,
+			 * and didn't have enough free; see comments at
+			 * start of routine
+			 */
+			ipath_dbg("Not enough free TIDs for %u pages "
+				  "(index %d), failing\n", cnt, i);
+			i--;	/* last tidlist[i] not filled in */
+			ret = -ENOMEM;
+			break;
+		}
+		tidlist[i] = tid;
+		ipath_cdbg(VERBOSE, "Updating idx %u to TID %u, "
+			   "vaddr %lx\n", i, tid, vaddr);
+		/* we "know" system pages and TID pages are same size */
+		dd->ipath_pageshadow[porttid + tid] = pagep[i];
+		/*
+		 * don't need atomic or it's overhead
+		 */
+		__set_bit(tid, tidmap);
+		physaddr = page_to_phys(pagep[i]);
+		ipath_stats.sps_pagelocks++;
+		ipath_cdbg(VERBOSE,
+			   "TID %u, vaddr %lx, physaddr %llx pgp %p\n",
+			   tid, vaddr, (unsigned long long) physaddr,
+			   pagep[i]);
+		dd->ipath_f_put_tid(dd, &tidbase[tid], 1, physaddr);
+		/*
+		 * don't check this tid in ipath_portshadow, since we
+		 * just filled it in; start with the next one.
+		 */
+		tid++;
+	}
+
+	if (ret) {
+		u32 limit;
+	cleanup:
+		/* jump here if copy out of updated info failed... */
+		ipath_dbg("After failure (ret=%d), undo %d of %d entries\n",
+			  -ret, i, cnt);
+		/* same code that's in ipath_free_tid() */
+		limit = sizeof(tidmap) * BITS_PER_BYTE;
+		if (limit > tidcnt)
+			/* just in case size changes in future */
+			limit = tidcnt;
+		tid = find_first_bit((const unsigned long *)tidmap, limit);
+		for (; tid < limit; tid++) {
+			if (!test_bit(tid, tidmap))
+				continue;
+			if (dd->ipath_pageshadow[porttid + tid]) {
+				ipath_cdbg(VERBOSE, "Freeing TID %u\n",
+					   tid);
+				dd->ipath_f_put_tid(dd, &tidbase[tid], 1,
+						    dd->ipath_tidinvalid);
+				dd->ipath_pageshadow[porttid + tid] = NULL;
+				ipath_stats.sps_pageunlocks++;
+			}
+		}
+		ipath_release_user_pages(pagep, cnt);
+	} else {
+		/*
+		 * Copy the updated array, with ipath_tid's filled in, back
+		 * to user.  Since we did the copy in already, this "should
+		 * never fail" If it does, we have to clean up...
+		 */
+		if (copy_to_user((void __user *)
+				 (unsigned long) ti->tidlist,
+				 tidlist, cnt * sizeof(*tidlist))) {
+			ret = -EFAULT;
+			goto cleanup;
+		}
+		if (copy_to_user((void __user *) (unsigned long) ti->tidmap,
+				 tidmap, sizeof tidmap)) {
+			ret = -EFAULT;
+			goto cleanup;
+		}
+		if (tid == tidcnt)
+			tid = 0;
+		pd->port_tidcursor = tid;
+	}
+
+done:
+	if (ret)
+		ipath_dbg("Failed to map %u TID pages, failing with %d\n",
+			  ti->tidcnt, -ret);
+	return ret;
+}
+
+/**
+ * ipath_tid_free - free a port TID
+ * @pd: the port
+ * @ti: the TID info
+ *
+ * right now we are unlocking one page at a time, but since
+ * the intended use of this routine is for a single group of
+ * virtually contiguous pages, that should change to improve
+ * performance.  We check that the TID is in range for this port
+ * but otherwise don't check validity; if user has an error and
+ * frees the wrong tid, it's only their own data that can thereby
+ * be corrupted.  We do check that the TID was in use, for sanity
+ * We always use our idea of the saved address, not the address that
+ * they pass in to us.
+ */
+
+static int ipath_tid_free(struct ipath_portdata *pd,
+			  const struct ipath_tid_info *ti)
+{
+	int ret = 0;
+	u32 tid, porttid, cnt, limit, tidcnt;
+	struct ipath_devdata *dd = pd->port_dd;
+	u64 __iomem *tidbase;
+	unsigned long tidmap[8];
+
+	if (!dd->ipath_pageshadow) {
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	if (copy_from_user(tidmap, (void __user *)(unsigned long)ti->tidmap,
+			   sizeof tidmap)) {
+		ret = -EFAULT;
+		goto done;
+	}
+
+	porttid = pd->port_port * dd->ipath_rcvtidcnt;
+	tidbase = (u64 __iomem *) ((char __iomem *)(dd->ipath_kregbase) +
+				   dd->ipath_rcvtidbase +
+				   porttid * sizeof(*tidbase));
+
+	tidcnt = dd->ipath_rcvtidcnt;
+	limit = sizeof(tidmap) * BITS_PER_BYTE;
+	if (limit > tidcnt)
+		/* just in case size changes in future */
+		limit = tidcnt;
+	tid = find_first_bit(tidmap, limit);
+	ipath_cdbg(VERBOSE, "Port%u free %u tids; first bit (max=%d) "
+		   "set is %d, porttid %u\n", pd->port_port, ti->tidcnt,
+		   limit, tid, porttid);
+	for (cnt = 0; tid < limit; tid++) {
+		/*
+		 * small optimization; if we detect a run of 3 or so without
+		 * any set, use find_first_bit again.  That's mainly to
+		 * accelerate the case where we wrapped, so we have some at
+		 * the beginning, and some at the end, and a big gap
+		 * in the middle.
+		 */
+		if (!test_bit(tid, tidmap))
+			continue;
+		cnt++;
+		if (dd->ipath_pageshadow[porttid + tid]) {
+			ipath_cdbg(VERBOSE, "PID %u freeing TID %u\n",
+				   pd->port_pid, tid);
+			dd->ipath_f_put_tid(dd, &tidbase[tid], 1,
+					    dd->ipath_tidinvalid);
+			ipath_release_user_pages(
+				&dd->ipath_pageshadow[porttid + tid], 1);
+			dd->ipath_pageshadow[porttid + tid] = NULL;
+			ipath_stats.sps_pageunlocks++;
+		} else
+			ipath_dbg("Unused tid %u, ignoring\n", tid);
+	}
+	if (cnt != ti->tidcnt)
+		ipath_dbg("passed in tidcnt %d, only %d bits set in map\n",
+			  ti->tidcnt, cnt);
+done:
+	if (ret)
+		ipath_dbg("Failed to unmap %u TID pages, failing with %d\n",
+			  ti->tidcnt, -ret);
+	return ret;
+}
+
+/**
+ * ipath_set_part_key - set a partition key
+ * @pd: the port
+ * @key: the key
+ *
+ * We can have up to 4 active at a time (other than the default, which is
+ * always allowed).  This is somewhat tricky, since multiple ports may set
+ * the same key, so we reference count them, and clean up at exit.  All 4
+ * partition keys are packed into a single infinipath register.  It's an
+ * error for a process to set the same pkey multiple times.  We provide no
+ * mechanism to de-allocate a pkey at this time, we may eventually need to
+ * do that.  I've used the atomic operations, and no locking, and only make
+ * a single pass through what's available.  This should be more than
+ * adequate for some time. I'll think about spinlocks or the like if and as
+ * it's necessary.
+ */
+static int ipath_set_part_key(struct ipath_portdata *pd, u16 key)
+{
+	struct ipath_devdata *dd = pd->port_dd;
+	int i, any = 0, pidx = -1;
+	u16 lkey = key & 0x7FFF;
+	int ret;
+
+	if (lkey == (IPS_DEFAULT_P_KEY & 0x7FFF)) {
+		/* nothing to do; this key always valid */
+		ret = 0;
+		goto bail;
+	}
+
+	ipath_cdbg(VERBOSE, "p%u try to set pkey %hx, current keys "
+		   "%hx:%x %hx:%x %hx:%x %hx:%x\n",
+		   pd->port_port, key, dd->ipath_pkeys[0],
+		   atomic_read(&dd->ipath_pkeyrefs[0]), dd->ipath_pkeys[1],
+		   atomic_read(&dd->ipath_pkeyrefs[1]), dd->ipath_pkeys[2],
+		   atomic_read(&dd->ipath_pkeyrefs[2]), dd->ipath_pkeys[3],
+		   atomic_read(&dd->ipath_pkeyrefs[3]));
+
+	if (!lkey) {
+		ipath_cdbg(PROC, "p%u tries to set key 0, not allowed\n",
+			   pd->port_port);
+		ret = -EINVAL;
+		goto bail;
+	}
+
+	/*
+	 * Set the full membership bit, because it has to be
+	 * set in the register or the packet, and it seems
+	 * cleaner to set in the register than to force all
+	 * callers to set it. (see bug 4331)
+	 */
+	key |= 0x8000;
+
+	for (i = 0; i < ARRAY_SIZE(pd->port_pkeys); i++) {
+		if (!pd->port_pkeys[i] && pidx == -1)
+			pidx = i;
+		if (pd->port_pkeys[i] == key) {
+			ipath_cdbg(VERBOSE, "p%u tries to set same pkey "
+				   "(%x) more than once\n",
+				   pd->port_port, key);
+			ret = -EEXIST;
+			goto bail;
+		}
+	}
+	if (pidx == -1) {
+		ipath_dbg("All pkeys for port %u already in use, "
+			  "can't set %x\n", pd->port_port, key);
+		ret = -EBUSY;
+		goto bail;
+	}
+	for (any = i = 0; i < ARRAY_SIZE(dd->ipath_pkeys); i++) {
+		if (!dd->ipath_pkeys[i]) {
+			any++;
+			continue;
+		}
+		if (dd->ipath_pkeys[i] == key) {
+			atomic_t *pkrefs = &dd->ipath_pkeyrefs[i];
+
+			if (atomic_inc_return(pkrefs) > 1) {
+				pd->port_pkeys[pidx] = key;
+				ipath_cdbg(VERBOSE, "p%u set key %x "
+					   "matches #%d, count now %d\n",
+					   pd->port_port, key, i,
+					   atomic_read(pkrefs));
+				ret = 0;
+				goto bail;
+			} else {
+				/*
+				 * lost race, decrement count, catch below
+				 */
+				atomic_dec(pkrefs);
+				ipath_cdbg(VERBOSE, "Lost race, count was "
+					   "0, after dec, it's %d\n",
+					   atomic_read(pkrefs));
+				any++;
+			}
+		}
+		if ((dd->ipath_pkeys[i] & 0x7FFF) == lkey) {
+			/*
+			 * It makes no sense to have both the limited and
+			 * full membership PKEY set at the same time since
+			 * the unlimited one will disable the limited one.
+			 */
+			ret = -EEXIST;
+			goto bail;
+		}
+	}
+	if (!any) {
+		ipath_dbg("port %u, all pkeys already in use, "
+			  "can't set %x\n", pd->port_port, key);
+		ret = -EBUSY;
+		goto bail;
+	}
+	for (any = i = 0; i < ARRAY_SIZE(dd->ipath_pkeys); i++) {
+		if (!dd->ipath_pkeys[i] &&
+		    atomic_inc_return(&dd->ipath_pkeyrefs[i]) == 1) {
+			u64 pkey;
+
+			/* for ipathstats, etc. */
+			ipath_stats.sps_pkeys[i] = lkey;
+			pd->port_pkeys[pidx] = dd->ipath_pkeys[i] = key;
+			pkey =
+				(u64) dd->ipath_pkeys[0] |
+				((u64) dd->ipath_pkeys[1] << 16) |
+				((u64) dd->ipath_pkeys[2] << 32) |
+				((u64) dd->ipath_pkeys[3] << 48);
+			ipath_cdbg(PROC, "p%u set key %x in #%d, "
+				   "portidx %d, new pkey reg %llx\n",
+				   pd->port_port, key, i, pidx,
+				   (unsigned long long) pkey);
+			ipath_write_kreg(
+				dd, dd->ipath_kregs->kr_partitionkey, pkey);
+
+			ret = 0;
+			goto bail;
+		}
+	}
+	ipath_dbg("port %u, all pkeys already in use 2nd pass, "
+		  "can't set %x\n", pd->port_port, key);
+	ret = -EBUSY;
+
+bail:
+	return ret;
+}
+
+/**
+ * ipath_manage_rcvq - manage a port's receive queue
+ * @pd: the port
+ * @start_stop: action to carry out
+ *
+ * start_stop == 0 disables receive on the port, for use in queue
+ * overflow conditions.  start_stop==1 re-enables, to be used to
+ * re-init the software copy of the head register
+ */
+static int ipath_manage_rcvq(struct ipath_portdata *pd, int start_stop)
+{
+	struct ipath_devdata *dd = pd->port_dd;
+	u64 tval;
+
+	ipath_cdbg(PROC, "%sabling rcv for unit %u port %u\n",
+		   start_stop ? "en" : "dis", dd->ipath_unit,
+		   pd->port_port);
+	/* atomically clear receive enable port. */
+	if (start_stop) {
+		/*
+		 * On enable, force in-memory copy of the tail register to
+		 * 0, so that protocol code doesn't have to worry about
+		 * whether or not the chip has yet updated the in-memory
+		 * copy or not on return from the system call. The chip
+		 * always resets it's tail register back to 0 on a
+		 * transition from disabled to enabled.  This could cause a
+		 * problem if software was broken, and did the enable w/o
+		 * the disable, but eventually the in-memory copy will be
+		 * updated and correct itself, even in the face of software
+		 * bugs.
+		 */
+		*pd->port_rcvhdrtail_kvaddr = 0;
+		set_bit(INFINIPATH_R_PORTENABLE_SHIFT + pd->port_port,
+			&dd->ipath_rcvctrl);
+	} else
+		clear_bit(INFINIPATH_R_PORTENABLE_SHIFT + pd->port_port,
+			  &dd->ipath_rcvctrl);
+	ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
+			 dd->ipath_rcvctrl);
+	/* now be sure chip saw it before we return */
+	tval = ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+	if (start_stop) {
+		/*
+		 * And try to be sure that tail reg update has happened too.
+		 * This should in theory interlock with the RXE changes to
+		 * the tail register.  Don't assign it to the tail register
+		 * in memory copy, since we could overwrite an update by the
+		 * chip if we did.
+		 */
+		tval = ipath_read_ureg32(dd, ur_rcvhdrtail, pd->port_port);
+	}
+	/* always; new head should be equal to new tail; see above */
+	return 0;
+}
+
+static void ipath_clean_part_key(struct ipath_portdata *pd,
+				 struct ipath_devdata *dd)
+{
+	int i, j, pchanged = 0;
+	u64 oldpkey;
+
+	/* for debugging only */
+	oldpkey = (u64) dd->ipath_pkeys[0] |
+		((u64) dd->ipath_pkeys[1] << 16) |
+		((u64) dd->ipath_pkeys[2] << 32) |
+		((u64) dd->ipath_pkeys[3] << 48);
+
+	for (i = 0; i < ARRAY_SIZE(pd->port_pkeys); i++) {
+		if (!pd->port_pkeys[i])
+			continue;
+		ipath_cdbg(VERBOSE, "look for key[%d] %hx in pkeys\n", i,
+			   pd->port_pkeys[i]);
+		for (j = 0; j < ARRAY_SIZE(dd->ipath_pkeys); j++) {
+			/* check for match independent of the global bit */
+			if ((dd->ipath_pkeys[j] & 0x7fff) !=
+			    (pd->port_pkeys[i] & 0x7fff))
+				continue;
+			if (atomic_dec_and_test(&dd->ipath_pkeyrefs[j])) {
+				ipath_cdbg(VERBOSE, "p%u clear key "
+					   "%x matches #%d\n",
+					   pd->port_port,
+					   pd->port_pkeys[i], j);
+				ipath_stats.sps_pkeys[j] =
+					dd->ipath_pkeys[j] = 0;
+				pchanged++;
+			}
+			else ipath_cdbg(
+				VERBOSE, "p%u key %x matches #%d, "
+				"but ref still %d\n", pd->port_port,
+				pd->port_pkeys[i], j,
+				atomic_read(&dd->ipath_pkeyrefs[j]));
+			break;
+		}
+		pd->port_pkeys[i] = 0;
+	}
+	if (pchanged) {
+		u64 pkey = (u64) dd->ipath_pkeys[0] |
+			((u64) dd->ipath_pkeys[1] << 16) |
+			((u64) dd->ipath_pkeys[2] << 32) |
+			((u64) dd->ipath_pkeys[3] << 48);
+		ipath_cdbg(VERBOSE, "p%u old pkey reg %llx, "
+			   "new pkey reg %llx\n", pd->port_port,
+			   (unsigned long long) oldpkey,
+			   (unsigned long long) pkey);
+		ipath_write_kreg(dd, dd->ipath_kregs->kr_partitionkey,
+				 pkey);
+	}
+}
+
+/**
+ * ipath_create_user_egr - allocate eager TID buffers
+ * @pd: the port to allocate TID buffers for
+ *
+ * This routine is now quite different for user and kernel, because
+ * the kernel uses skb's, for the accelerated network performance
+ * This is the user port version
+ *
+ * Allocate the eager TID buffers and program them into infinipath
+ * They are no longer completely contiguous, we do multiple allocation
+ * calls.
+ */
+static int ipath_create_user_egr(struct ipath_portdata *pd)
+{
+	struct ipath_devdata *dd = pd->port_dd;
+	unsigned e, egrcnt, alloced, egrperchunk, chunk, egrsize, egroff;
+	size_t size;
+	int ret;
+
+	egrcnt = dd->ipath_rcvegrcnt;
+	/* TID number offset for this port */
+	egroff = pd->port_port * egrcnt;
+	egrsize = dd->ipath_rcvegrbufsize;
+	ipath_cdbg(VERBOSE, "Allocating %d egr buffers, at egrtid "
+		   "offset %x, egrsize %u\n", egrcnt, egroff, egrsize);
+
+	/*
+	 * to avoid wasting a lot of memory, we allocate 32KB chunks of
+	 * physically contiguous memory, advance through it until used up
+	 * and then allocate more.  Of course, we need memory to store those
+	 * extra pointers, now.  Started out with 256KB, but under heavy
+	 * memory pressure (creating large files and then copying them over
+	 * NFS while doing lots of MPI jobs), we hit some allocation
+	 * failures, even though we can sleep...  (2.6.10) Still get
+	 * failures at 64K.  32K is the lowest we can go without waiting
+	 * more memory again.  It seems likely that the coalescing in
+	 * free_pages, etc. still has issues (as it has had previously
+	 * during 2.6.x development).
+	 */
+	size = 0x8000;
+	alloced = ALIGN(egrsize * egrcnt, size);
+	egrperchunk = size / egrsize;
+	chunk = (egrcnt + egrperchunk - 1) / egrperchunk;
+	pd->port_rcvegrbuf_chunks = chunk;
+	pd->port_rcvegrbufs_perchunk = egrperchunk;
+	pd->port_rcvegrbuf_size = size;
+	pd->port_rcvegrbuf = vmalloc(chunk * sizeof(pd->port_rcvegrbuf[0]));
+	if (!pd->port_rcvegrbuf) {
+		ret = -ENOMEM;
+		goto bail;
+	}
+	pd->port_rcvegrbuf_phys =
+		vmalloc(chunk * sizeof(pd->port_rcvegrbuf_phys[0]));
+	if (!pd->port_rcvegrbuf_phys) {
+		ret = -ENOMEM;
+		goto bail_rcvegrbuf;
+	}
+	for (e = 0; e < pd->port_rcvegrbuf_chunks; e++) {
+		/*
+		 * GFP_USER, but without GFP_FS, so buffer cache can be
+		 * coalesced (we hope); otherwise, even at order 4,
+		 * heavy filesystem activity makes these fail
+		 */
+		gfp_t gfp_flags = __GFP_WAIT | __GFP_IO | __GFP_COMP;
+
+		pd->port_rcvegrbuf[e] = dma_alloc_coherent(
+			&dd->pcidev->dev, size, &pd->port_rcvegrbuf_phys[e],
+			gfp_flags);
+
+		if (!pd->port_rcvegrbuf[e]) {
+			ret = -ENOMEM;
+			goto bail_rcvegrbuf_phys;
+		}
+	}
+
+	pd->port_rcvegr_phys = pd->port_rcvegrbuf_phys[0];
+
+	for (e = chunk = 0; chunk < pd->port_rcvegrbuf_chunks; chunk++) {
+		dma_addr_t pa = pd->port_rcvegrbuf_phys[chunk];
+		unsigned i;
+
+		for (i = 0; e < egrcnt && i < egrperchunk; e++, i++) {
+			dd->ipath_f_put_tid(dd, e + egroff +
+					    (u64 __iomem *)
+					    ((char __iomem *)
+					     dd->ipath_kregbase +
+					     dd->ipath_rcvegrbase), 0, pa);
+			pa += egrsize;
+		}
+		cond_resched();	/* don't hog the cpu */
+	}
+
+	ret = 0;
+	goto bail;
+
+bail_rcvegrbuf_phys:
+	for (e = 0; e < pd->port_rcvegrbuf_chunks &&
+		     pd->port_rcvegrbuf[e]; e++)
+		dma_free_coherent(&dd->pcidev->dev, size,
+				  pd->port_rcvegrbuf[e],
+				  pd->port_rcvegrbuf_phys[e]);
+
+	vfree(pd->port_rcvegrbuf_phys);
+	pd->port_rcvegrbuf_phys = NULL;
+bail_rcvegrbuf:
+	vfree(pd->port_rcvegrbuf);
+	pd->port_rcvegrbuf = NULL;
+bail:
+	return ret;
+}
+
+static int ipath_do_user_init(struct ipath_portdata *pd,
+			      const struct ipath_user_info *uinfo)
+{
+	int ret = 0;
+	struct ipath_devdata *dd = pd->port_dd;
+	u64 physaddr, uaddr, off, atmp;
+	struct page *pagep;
+	u32 head32;
+	u64 head;
+
+	/* for now, if major version is different, bail */
+	if ((uinfo->spu_userversion >> 16) != IPATH_USER_SWMAJOR) {
+		dev_info(&dd->pcidev->dev,
+			 "User major version %d not same as driver "
+			 "major %d\n", uinfo->spu_userversion >> 16,
+			 IPATH_USER_SWMAJOR);
+		ret = -ENODEV;
+		goto done;
+	}
+
+	if ((uinfo->spu_userversion & 0xffff) != IPATH_USER_SWMINOR)
+		ipath_dbg("User minor version %d not same as driver "
+			  "minor %d\n", uinfo->spu_userversion & 0xffff,
+			  IPATH_USER_SWMINOR);
+
+	if (uinfo->spu_rcvhdrsize) {
+		ret = ipath_setrcvhdrsize(dd, uinfo->spu_rcvhdrsize);
+		if (ret)
+			goto done;
+	}
+
+	/* for now we do nothing with rcvhdrcnt: uinfo->spu_rcvhdrcnt */
+
+	/* set up for the rcvhdr Q tail register writeback to user memory */
+	if (!uinfo->spu_rcvhdraddr ||
+	    !access_ok(VERIFY_WRITE, (u64 __user *) (unsigned long)
+		       uinfo->spu_rcvhdraddr, sizeof(u64))) {
+		ipath_dbg("Port %d rcvhdrtail addr %llx not valid\n",
+			  pd->port_port,
+			  (unsigned long long) uinfo->spu_rcvhdraddr);
+		ret = -EINVAL;
+		goto done;
+	}
+
+	off = offset_in_page(uinfo->spu_rcvhdraddr);
+	uaddr = PAGE_MASK & (unsigned long) uinfo->spu_rcvhdraddr;
+	ret = ipath_get_user_pages_nocopy(uaddr, &pagep);
+	if (ret) {
+		dev_info(&dd->pcidev->dev, "Failed to lookup and lock "
+			 "address %llx for rcvhdrtail: errno %d\n",
+			 (unsigned long long) uinfo->spu_rcvhdraddr, -ret);
+		goto done;
+	}
+	ipath_stats.sps_pagelocks++;
+	pd->port_rcvhdrtail_uaddr = uaddr;
+	pd->port_rcvhdrtail_pagep = pagep;
+	pd->port_rcvhdrtail_kvaddr =
+		page_address(pagep);
+	pd->port_rcvhdrtail_kvaddr += off;
+	physaddr = page_to_phys(pagep) + off;
+	ipath_cdbg(VERBOSE, "port %d user addr %llx hdrtailaddr, %llx "
+		   "physical (off=%llx)\n",
+		   pd->port_port,
+		   (unsigned long long) uinfo->spu_rcvhdraddr,
+		   (unsigned long long) physaddr, (unsigned long long) off);
+	ipath_write_kreg_port(dd, dd->ipath_kregs->kr_rcvhdrtailaddr,
+			      pd->port_port, physaddr);
+	atmp = ipath_read_kreg64_port(dd,
+				      dd->ipath_kregs->kr_rcvhdrtailaddr,
+				      pd->port_port);
+	if (physaddr != atmp) {
+		ipath_dev_err(dd,
+			      "Catastrophic software error, "
+			      "RcvHdrTailAddr%u written as %llx, "
+			      "read back as %llx\n", pd->port_port,
+			      (unsigned long long) physaddr,
+			      (unsigned long long) atmp);
+		ret = -EINVAL;
+		goto done;
+	}
+
+	/* for right now, kernel piobufs are at end, so port 1 is at 0 */
+	pd->port_piobufs = dd->ipath_piobufbase +
+		dd->ipath_pbufsport * (pd->port_port -
+				       1) * dd->ipath_palign;
+	ipath_cdbg(VERBOSE, "Set base of piobufs for port %u to 0x%x\n",
+		   pd->port_port, pd->port_piobufs);
+
+	/*
+	 * Now allocate the rcvhdr Q and eager TIDs; skip the TID
+	 * array for time being.  If pd->port_port > chip-supported,
+	 * we need to do extra stuff here to handle by handling overflow
+	 * through port 0, someday
+	 */
+	ret = ipath_create_rcvhdrq(dd, pd);
+	if (!ret)
+		ret = ipath_create_user_egr(pd);
+	if (ret)
+		goto done;
+	/* enable receives now */
+	/* atomically set enable bit for this port */
+	set_bit(INFINIPATH_R_PORTENABLE_SHIFT + pd->port_port,
+		&dd->ipath_rcvctrl);
+
+	/*
+	 * set the head registers for this port to the current values
+	 * of the tail pointers, since we don't know if they were
+	 * updated on last use of the port.
+	 */
+	head32 = ipath_read_ureg32(dd, ur_rcvhdrtail, pd->port_port);
+	head = (u64) head32;
+	ipath_write_ureg(dd, ur_rcvhdrhead, head, pd->port_port);
+	head32 = ipath_read_ureg32(dd, ur_rcvegrindextail, pd->port_port);
+	ipath_write_ureg(dd, ur_rcvegrindexhead, head32, pd->port_port);
+	dd->ipath_lastegrheads[pd->port_port] = -1;
+	dd->ipath_lastrcvhdrqtails[pd->port_port] = -1;
+	ipath_cdbg(VERBOSE, "Wrote port%d head %llx, egrhead %x from "
+		   "tail regs\n", pd->port_port,
+		   (unsigned long long) head, head32);
+	pd->port_tidcursor = 0;	/* start at beginning after open */
+	/*
+	 * now enable the port; the tail registers will be written to memory
+	 * by the chip as soon as it sees the write to
+	 * dd->ipath_kregs->kr_rcvctrl.  The update only happens on
+	 * transition from 0 to 1, so clear it first, then set it as part of
+	 * enabling the port.  This will (very briefly) affect any other
+	 * open ports, but it shouldn't be long enough to be an issue.
+	 */
+	ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
+			 dd->ipath_rcvctrl & ~INFINIPATH_R_TAILUPD);
+	ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
+			 dd->ipath_rcvctrl);
+
+done:
+	return ret;
+}
+
+static int mmap_ureg(struct vm_area_struct *vma, struct ipath_devdata *dd,
+		     u64 ureg)
+{
+	unsigned long phys;
+	int ret;
+
+	/* it's the real hardware, so io_remap works */
+
+	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
+		dev_info(&dd->pcidev->dev, "FAIL mmap userreg: reqlen "
+			 "%lx > PAGE\n", vma->vm_end - vma->vm_start);
+		ret = -EFAULT;
+	} else {
+		phys = dd->ipath_physaddr + ureg;
+		vma->vm_page_prot = pgprot_noncached(vma->vm_page_prot);
+
+		vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND;
+		ret = io_remap_pfn_range(vma, vma->vm_start,
+					 phys >> PAGE_SHIFT,
+					 vma->vm_end - vma->vm_start,
+					 vma->vm_page_prot);
+	}
+	return ret;
+}
+
+static int mmap_piobufs(struct vm_area_struct *vma,
+			struct ipath_devdata *dd,
+			struct ipath_portdata *pd)
+{
+	unsigned long phys;
+	int ret;
+
+	/*
+	 * When we map the PIO buffers, we want to map them as writeonly, no
+	 * read possible.
+	 */
+
+	if ((vma->vm_end - vma->vm_start) >
+	    (dd->ipath_pbufsport * dd->ipath_palign)) {
+		dev_info(&dd->pcidev->dev, "FAIL mmap piobufs: "
+			 "reqlen %lx > PAGE\n",
+			 vma->vm_end - vma->vm_start);
+		ret = -EFAULT;
+		goto bail;
+	}
+
+	phys = dd->ipath_physaddr + pd->port_piobufs;
+	/*
+	 * Do *NOT* mark this as non-cached (PWT bit), or we don't get the
+	 * write combining behavior we want on the PIO buffers!
+	 * vma->vm_page_prot =
+	 *        pgprot_noncached(vma->vm_page_prot);
+	 */
+
+	if (vma->vm_flags & VM_READ) {
+		dev_info(&dd->pcidev->dev,
+			 "Can't map piobufs as readable (flags=%lx)\n",
+			 vma->vm_flags);
+		ret = -EPERM;
+		goto bail;
+	}
+
+	/* don't allow them to later change to readable with mprotect */
+
+	vma->vm_flags &= ~VM_MAYWRITE;
+	vma->vm_flags |= VM_DONTCOPY | VM_DONTEXPAND;
+
+	ret = io_remap_pfn_range(vma, vma->vm_start, phys >> PAGE_SHIFT,
+				 vma->vm_end - vma->vm_start,
+				 vma->vm_page_prot);
+bail:
+	return ret;
+}
+
+static int mmap_rcvegrbufs(struct vm_area_struct *vma,
+			   struct ipath_portdata *pd)
+{
+	struct ipath_devdata *dd = pd->port_dd;
+	unsigned long start, size;
+	size_t total_size, i;
+	dma_addr_t *phys;
+	int ret;
+
+	if (!pd->port_rcvegrbuf) {
+		ret = -EFAULT;
+		goto bail;
+	}
+
+	size = pd->port_rcvegrbuf_size;
+	total_size = pd->port_rcvegrbuf_chunks * size;
+	if ((vma->vm_end - vma->vm_start) > total_size) {
+		dev_info(&dd->pcidev->dev, "FAIL on egr bufs: "
+			 "reqlen %lx > actual %lx\n",
+			 vma->vm_end - vma->vm_start,
+			 (unsigned long) total_size);
+		ret = -EFAULT;
+		goto bail;
+	}
+
+	if (vma->vm_flags & VM_WRITE) {
+		dev_info(&dd->pcidev->dev, "Can't map eager buffers as "
+			 "writable (flags=%lx)\n", vma->vm_flags);
+		ret = -EPERM;
+		goto bail;
+	}
+
+	start = vma->vm_start;
+	phys = pd->port_rcvegrbuf_phys;
+
+	/* don't allow them to later change to writeable with mprotect */
+	vma->vm_flags &= ~VM_MAYWRITE;
+
+	for (i = 0; i < pd->port_rcvegrbuf_chunks; i++, start += size) {
+		ret = remap_pfn_range(vma, start, phys[i] >> PAGE_SHIFT,
+				      size, vma->vm_page_prot);
+		if (ret < 0)
+			goto bail;
+	}
+	ret = 0;
+
+bail:
+	return ret;
+}
+
+static int mmap_rcvhdrq(struct vm_area_struct *vma,
+			struct ipath_portdata *pd)
+{
+	struct ipath_devdata *dd = pd->port_dd;
+	size_t total_size;
+	int ret;
+
+	/*
+	 * kmalloc'ed memory, physically contiguous; this is from
+	 * spi_rcvhdr_base; we allow user to map read-write so they can
+	 * write hdrq entries to allow protocol code to directly poll
+	 * whether a hdrq entry has been written.
+	 */
+	total_size = ALIGN(dd->ipath_rcvhdrcnt * dd->ipath_rcvhdrentsize *
+			   sizeof(u32), PAGE_SIZE);
+	if ((vma->vm_end - vma->vm_start) > total_size) {
+		dev_info(&dd->pcidev->dev,
+			 "FAIL on rcvhdrq: reqlen %lx > actual %lx\n",
+			 vma->vm_end - vma->vm_start,
+			 (unsigned long) total_size);
+		ret = -EFAULT;
+		goto bail;
+	}
+
+	ret = remap_pfn_range(vma, vma->vm_start,
+			      pd->port_rcvhdrq_phys >> PAGE_SHIFT,
+			      vma->vm_end - vma->vm_start,
+			      vma->vm_page_prot);
+bail:
+	return ret;
+}
+
+static int mmap_pioavailregs(struct vm_area_struct *vma,
+			     struct ipath_portdata *pd)
+{
+	struct ipath_devdata *dd = pd->port_dd;
+	int ret;
+
+	/*
+	 * when we map the PIO bufferavail registers, we want to map them as
+	 * readonly, no write possible.
+	 *
+	 * kmalloc'ed memory, physically contiguous, one page only, readonly
+	 */
+
+	if ((vma->vm_end - vma->vm_start) > PAGE_SIZE) {
+		dev_info(&dd->pcidev->dev, "FAIL on pioavailregs_dma: "
+			 "reqlen %lx > actual %lx\n",
+			 vma->vm_end - vma->vm_start,
+			 (unsigned long) PAGE_SIZE);
+		ret = -EFAULT;
+		goto bail;
+	}
+
+	if (vma->vm_flags & VM_WRITE) {
+		dev_info(&dd->pcidev->dev,
+			 "Can't map pioavailregs as writable (flags=%lx)\n",
+			 vma->vm_flags);
+		ret = -EPERM;
+		goto bail;
+	}
+
+	/* don't allow them to later change with mprotect */
+	vma->vm_flags &= ~VM_MAYWRITE;
+
+	ret = remap_pfn_range(vma, vma->vm_start,
+			      dd->ipath_pioavailregs_phys >> PAGE_SHIFT,
+			      PAGE_SIZE, vma->vm_page_prot);
+bail:
+	return ret;
+}
+
+/**
+ * ipath_mmap - mmap various structures into user space
+ * @fp: the file pointer
+ * @vma: the VM area
+ *
+ * We use this to have a shared buffer between the kernel and the user code
+ * for the rcvhdr queue, egr buffers, and the per-port user regs and pio
+ * buffers in the chip.  We have the open and close entries so we can bump
+ * the ref count and keep the driver from being unloaded while still mapped.
+ */
+static int ipath_mmap(struct file *fp, struct vm_area_struct *vma)
+{
+	struct ipath_portdata *pd;
+	struct ipath_devdata *dd;
+	u64 pgaddr, ureg;
+	int ret;
+
+	pd = port_fp(fp);
+	dd = pd->port_dd;
+	/*
+	 * This is the ipath_do_user_init() code, mapping the shared buffers
+	 * into the user process. The address referred to by vm_pgoff is the
+	 * virtual, not physical, address; we only do one mmap for each
+	 * space mapped.
+	 */
+	pgaddr = vma->vm_pgoff << PAGE_SHIFT;
+
+	/*
+	 * note that ureg does *NOT* have the kregvirt as part of it, to be
+	 * sure that for 32 bit programs, we don't end up trying to map a >
+	 * 44 address.  Has to match ipath_get_base_info() code that sets
+	 * __spi_uregbase
+	 */
+
+	ureg = dd->ipath_uregbase + dd->ipath_palign * pd->port_port;
+
+	ipath_cdbg(MM, "ushare: pgaddr %llx vm_start=%lx, vmlen %lx\n",
+		   (unsigned long long) pgaddr, vma->vm_start,
+		   vma->vm_end - vma->vm_start);
+
+	if (pgaddr == ureg)
+		ret = mmap_ureg(vma, dd, ureg);
+	else if (pgaddr == pd->port_piobufs)
+		ret = mmap_piobufs(vma, dd, pd);
+	else if (pgaddr == (u64) pd->port_rcvegr_phys)
+		ret = mmap_rcvegrbufs(vma, pd);
+	else if (pgaddr == (u64) pd->port_rcvhdrq_phys)
+		ret = mmap_rcvhdrq(vma, pd);
+	else if (pgaddr == dd->ipath_pioavailregs_phys)
+		ret = mmap_pioavailregs(vma, pd);
+	else
+		ret = -EINVAL;
+
+	vma->vm_private_data = NULL;
+
+	if (ret < 0)
+		dev_info(&dd->pcidev->dev,
+			 "Failure %d on addr %lx, off %lx\n",
+			 -ret, vma->vm_start, vma->vm_pgoff);
+
+	return ret;
+}
+
+static unsigned int ipath_poll(struct file *fp,
+			       struct poll_table_struct *pt)
+{
+	struct ipath_portdata *pd;
+	u32 head, tail;
+	int bit;
+	struct ipath_devdata *dd;
+
+	pd = port_fp(fp);
+	dd = pd->port_dd;
+
+	bit = pd->port_port + INFINIPATH_R_INTRAVAIL_SHIFT;
+	set_bit(bit, &dd->ipath_rcvctrl);
+
+	/*
+	 * Before blocking, make sure that head is still == tail,
+	 * reading from the chip, so we can be sure the interrupt
+	 * enable has made it to the chip.  If not equal, disable
+	 * interrupt again and return immediately.  This avoids races,
+	 * and the overhead of the chip read doesn't matter much at
+	 * this point, since we are waiting for something anyway.
+	 */
+
+	ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
+			 dd->ipath_rcvctrl);
+
+	head = ipath_read_ureg32(dd, ur_rcvhdrhead, pd->port_port);
+	tail = ipath_read_ureg32(dd, ur_rcvhdrtail, pd->port_port);
+
+	if (tail == head) {
+		set_bit(IPATH_PORT_WAITING_RCV, &pd->port_flag);
+		poll_wait(fp, &pd->port_wait, pt);
+
+		if (test_bit(IPATH_PORT_WAITING_RCV, &pd->port_flag)) {
+			/* timed out, no packets received */
+			clear_bit(IPATH_PORT_WAITING_RCV, &pd->port_flag);
+			pd->port_rcvwait_to++;
+		}
+	}
+	else {
+		/* it's already happened; don't do wait_event overhead */
+		pd->port_rcvnowait++;
+	}
+
+	clear_bit(bit, &dd->ipath_rcvctrl);
+	ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
+			 dd->ipath_rcvctrl);
+
+	return 0;
+}
+
+static int try_alloc_port(struct ipath_devdata *dd, int port,
+			  struct file *fp)
+{
+	int ret;
+
+	if (!dd->ipath_pd[port]) {
+		void *p, *ptmp;
+
+		p = kzalloc(sizeof(struct ipath_portdata), GFP_KERNEL);
+
+		/*
+		 * Allocate memory for use in ipath_tid_update() just once
+		 * at open, not per call.  Reduces cost of expected send
+		 * setup.
+		 */
+		ptmp = kmalloc(dd->ipath_rcvtidcnt * sizeof(u16) +
+			       dd->ipath_rcvtidcnt * sizeof(struct page **),
+			       GFP_KERNEL);
+		if (!p || !ptmp) {
+			ipath_dev_err(dd, "Unable to allocate portdata "
+				      "memory, failing open\n");
+			ret = -ENOMEM;
+			kfree(p);
+			kfree(ptmp);
+			goto bail;
+		}
+		dd->ipath_pd[port] = p;
+		dd->ipath_pd[port]->port_port = port;
+		dd->ipath_pd[port]->port_dd = dd;
+		dd->ipath_pd[port]->port_tid_pg_list = ptmp;
+		init_waitqueue_head(&dd->ipath_pd[port]->port_wait);
+	}
+	if (!dd->ipath_pd[port]->port_cnt) {
+		dd->ipath_pd[port]->port_cnt = 1;
+		fp->private_data = (void *) dd->ipath_pd[port];
+		ipath_cdbg(PROC, "%s[%u] opened unit:port %u:%u\n",
+			   current->comm, current->pid, dd->ipath_unit,
+			   port);
+		dd->ipath_pd[port]->port_pid = current->pid;
+		strncpy(dd->ipath_pd[port]->port_comm, current->comm,
+			sizeof(dd->ipath_pd[port]->port_comm));
+		ipath_stats.sps_ports++;
+		ret = 0;
+		goto bail;
+	}
+	ret = -EBUSY;
+
+bail:
+	return ret;
+}
+
+static inline int usable(struct ipath_devdata *dd)
+{
+	return dd &&
+		(dd->ipath_flags & IPATH_PRESENT) &&
+		dd->ipath_kregbase &&
+		dd->ipath_lid &&
+		!(dd->ipath_flags & (IPATH_LINKDOWN | IPATH_DISABLED
+				     | IPATH_LINKUNK));
+}
+
+static int find_free_port(int unit, struct file *fp)
+{
+	struct ipath_devdata *dd = ipath_lookup(unit);
+	int ret, i;
+
+	if (!dd) {
+		ret = -ENODEV;
+		goto bail;
+	}
+
+	if (!usable(dd)) {
+		ret = -ENETDOWN;
+		goto bail;
+	}
+
+	for (i = 0; i < dd->ipath_cfgports; i++) {
+		ret = try_alloc_port(dd, i, fp);
+		if (ret != -EBUSY)
+			goto bail;
+	}
+	ret = -EBUSY;
+
+bail:
+	return ret;
+}
+
+static int find_best_unit(struct file *fp)
+{
+	int ret = 0, i, prefunit = -1, devmax;
+	int maxofallports, npresent, nup;
+	int ndev;
+
+	(void) ipath_count_units(&npresent, &nup, &maxofallports);
+
+	/*
+	 * This code is present to allow a knowledgeable person to
+	 * specify the layout of processes to processors before opening
+	 * this driver, and then we'll assign the process to the "closest"
+	 * HT-400 to that processor (we assume reasonable connectivity,
+	 * for now).  This code assumes that if affinity has been set
+	 * before this point, that at most one cpu is set; for now this
+	 * is reasonable.  I check for both cpus_empty() and cpus_full(),
+	 * in case some kernel variant sets none of the bits when no
+	 * affinity is set.  2.6.11 and 12 kernels have all present
+	 * cpus set.  Some day we'll have to fix it up further to handle
+	 * a cpu subset.  This algorithm fails for two HT-400's connected
+	 * in tunnel fashion.  Eventually this needs real topology
+	 * information.  There may be some issues with dual core numbering
+	 * as well.  This needs more work prior to release.
+	 */
+	if (!cpus_empty(current->cpus_allowed) &&
+	    !cpus_full(current->cpus_allowed)) {
+		int ncpus = num_online_cpus(), curcpu = -1;
+		for (i = 0; i < ncpus; i++)
+			if (cpu_isset(i, current->cpus_allowed)) {
+				ipath_cdbg(PROC, "%s[%u] affinity set for "
+					   "cpu %d\n", current->comm,
+					   current->pid, i);
+				curcpu = i;
+			}
+		if (curcpu != -1) {
+			if (npresent) {
+				prefunit = curcpu / (ncpus / npresent);
+				ipath_dbg("%s[%u] %d chips, %d cpus, "
+					  "%d cpus/chip, select unit %d\n",
+					  current->comm, current->pid,
+					  npresent, ncpus, ncpus / npresent,
+					  prefunit);
+			}
+		}
+	}
+
+	/*
+	 * user ports start at 1, kernel port is 0
+	 * For now, we do round-robin access across all chips
+	 */
+
+	if (prefunit != -1)
+		devmax = prefunit + 1;
+	else
+		devmax = ipath_count_units(NULL, NULL, NULL);
+recheck:
+	for (i = 1; i < maxofallports; i++) {
+		for (ndev = prefunit != -1 ? prefunit : 0; ndev < devmax;
+		     ndev++) {
+			struct ipath_devdata *dd = ipath_lookup(ndev);
+
+			if (!usable(dd))
+				continue; /* can't use this unit */
+			if (i >= dd->ipath_cfgports)
+				/*
+				 * Maxed out on users of this unit. Try
+				 * next.
+				 */
+				continue;
+			ret = try_alloc_port(dd, i, fp);
+			if (!ret)
+				goto done;
+		}
+	}
+
+	if (npresent) {
+		if (nup == 0) {
+			ret = -ENETDOWN;
+			ipath_dbg("No ports available (none initialized "
+				  "and ready)\n");
+		} else {
+			if (prefunit > 0) {
+				/* if started above 0, retry from 0 */
+				ipath_cdbg(PROC,
+					   "%s[%u] no ports on prefunit "
+					   "%d, clear and re-check\n",
+					   current->comm, current->pid,
+					   prefunit);
+				devmax = ipath_count_units(NULL, NULL,
+							   NULL);
+				prefunit = -1;
+				goto recheck;
+			}
+			ret = -EBUSY;
+			ipath_dbg("No ports available\n");
+		}
+	} else {
+		ret = -ENXIO;
+		ipath_dbg("No boards found\n");
+	}
+
+done:
+	return ret;
+}
+
+static int ipath_open(struct inode *in, struct file *fp)
+{
+	int ret, minor;
+
+	mutex_lock(&ipath_mutex);
+
+	minor = iminor(in);
+	ipath_cdbg(VERBOSE, "open on dev %lx (minor %d)\n",
+		   (long)in->i_rdev, minor);
+
+	if (minor)
+		ret = find_free_port(minor - 1, fp);
+	else
+		ret = find_best_unit(fp);
+
+	mutex_unlock(&ipath_mutex);
+	return ret;
+}
+
+/**
+ * unlock_exptid - unlock any expected TID entries port still had in use
+ * @pd: port
+ *
+ * We don't actually update the chip here, because we do a bulk update
+ * below, using ipath_f_clear_tids.
+ */
+static void unlock_expected_tids(struct ipath_portdata *pd)
+{
+	struct ipath_devdata *dd = pd->port_dd;
+	int port_tidbase = pd->port_port * dd->ipath_rcvtidcnt;
+	int i, cnt = 0, maxtid = port_tidbase + dd->ipath_rcvtidcnt;
+
+	ipath_cdbg(VERBOSE, "Port %u unlocking any locked expTID pages\n",
+		   pd->port_port);
+	for (i = port_tidbase; i < maxtid; i++) {
+		if (!dd->ipath_pageshadow[i])
+			continue;
+
+		ipath_release_user_pages_on_close(&dd->ipath_pageshadow[i],
+						  1);
+		dd->ipath_pageshadow[i] = NULL;
+		cnt++;
+		ipath_stats.sps_pageunlocks++;
+	}
+	if (cnt)
+		ipath_cdbg(VERBOSE, "Port %u locked %u expTID entries\n",
+			   pd->port_port, cnt);
+
+	if (ipath_stats.sps_pagelocks || ipath_stats.sps_pageunlocks)
+		ipath_cdbg(VERBOSE, "%llu pages locked, %llu unlocked\n",
+			   (unsigned long long) ipath_stats.sps_pagelocks,
+			   (unsigned long long)
+			   ipath_stats.sps_pageunlocks);
+}
+
+static int ipath_close(struct inode *in, struct file *fp)
+{
+	int ret = 0;
+	struct ipath_portdata *pd;
+	struct ipath_devdata *dd;
+	unsigned port;
+
+	ipath_cdbg(VERBOSE, "close on dev %lx, private data %p\n",
+		   (long)in->i_rdev, fp->private_data);
+
+	mutex_lock(&ipath_mutex);
+
+	pd = port_fp(fp);
+	port = pd->port_port;
+	fp->private_data = NULL;
+	dd = pd->port_dd;
+
+	if (pd->port_hdrqfull) {
+		ipath_cdbg(PROC, "%s[%u] had %u rcvhdrqfull errors "
+			   "during run\n", pd->port_comm, pd->port_pid,
+			   pd->port_hdrqfull);
+		pd->port_hdrqfull = 0;
+	}
+
+	if (pd->port_rcvwait_to || pd->port_piowait_to
+	    || pd->port_rcvnowait || pd->port_pionowait) {
+		ipath_cdbg(VERBOSE, "port%u, %u rcv, %u pio wait timeo; "
+			   "%u rcv %u, pio already\n",
+			   pd->port_port, pd->port_rcvwait_to,
+			   pd->port_piowait_to, pd->port_rcvnowait,
+			   pd->port_pionowait);
+		pd->port_rcvwait_to = pd->port_piowait_to =
+			pd->port_rcvnowait = pd->port_pionowait = 0;
+	}
+	if (pd->port_flag) {
+		ipath_dbg("port %u port_flag still set to 0x%lx\n",
+			  pd->port_port, pd->port_flag);
+		pd->port_flag = 0;
+	}
+
+	if (dd->ipath_kregbase) {
+		if (pd->port_rcvhdrtail_uaddr) {
+			pd->port_rcvhdrtail_uaddr = 0;
+			pd->port_rcvhdrtail_kvaddr = NULL;
+			ipath_release_user_pages_on_close(
+				&pd->port_rcvhdrtail_pagep, 1);
+			pd->port_rcvhdrtail_pagep = NULL;
+			ipath_stats.sps_pageunlocks++;
+		}
+		ipath_write_kreg_port(
+			dd, dd->ipath_kregs->kr_rcvhdrtailaddr,
+			port, 0ULL);
+		ipath_write_kreg_port(
+			dd, dd->ipath_kregs->kr_rcvhdraddr,
+			pd->port_port, 0);
+
+		/* clean up the pkeys for this port user */
+		ipath_clean_part_key(pd, dd);
+
+		if (port < dd->ipath_cfgports) {
+			int i = dd->ipath_pbufsport * (port - 1);
+			ipath_disarm_piobufs(dd, i, dd->ipath_pbufsport);
+
+			/* atomically clear receive enable port. */
+			clear_bit(INFINIPATH_R_PORTENABLE_SHIFT + port,
+				  &dd->ipath_rcvctrl);
+			ipath_write_kreg(
+				dd,
+				dd->ipath_kregs->kr_rcvctrl,
+				dd->ipath_rcvctrl);
+
+			if (dd->ipath_pageshadow)
+				unlock_expected_tids(pd);
+			ipath_stats.sps_ports--;
+			ipath_cdbg(PROC, "%s[%u] closed port %u:%u\n",
+				   pd->port_comm, pd->port_pid,
+				   dd->ipath_unit, port);
+		}
+	}
+
+	pd->port_cnt = 0;
+	pd->port_pid = 0;
+
+	dd->ipath_f_clear_tids(dd, pd->port_port);
+
+	ipath_free_pddata(dd, pd->port_port, 0);
+
+	mutex_unlock(&ipath_mutex);
+
+	return ret;
+}
+
+static int ipath_port_info(struct ipath_portdata *pd,
+			   struct ipath_port_info __user *uinfo)
+{
+	struct ipath_port_info info;
+	int nup;
+	int ret;
+
+	(void) ipath_count_units(NULL, &nup, NULL);
+	info.num_active = nup;
+	info.unit = pd->port_dd->ipath_unit;
+	info.port = pd->port_port;
+
+	if (copy_to_user(uinfo, &info, sizeof(info))) {
+		ret = -EFAULT;
+		goto bail;
+	}
+	ret = 0;
+
+bail:
+	return ret;
+}
+
+static ssize_t ipath_write(struct file *fp, const char __user *data,
+			   size_t count, loff_t *off)
+{
+	const struct ipath_cmd __user *ucmd;
+	struct ipath_portdata *pd;
+	const void __user *src;
+	size_t consumed, copy;
+	struct ipath_cmd cmd;
+	ssize_t ret = 0;
+	void *dest;
+
+	if (count < sizeof(cmd.type)) {
+		ret = -EINVAL;
+		goto bail;
+	}
+
+	ucmd = (const struct ipath_cmd __user *) data;
+
+	if (copy_from_user(&cmd.type, &ucmd->type, sizeof(cmd.type))) {
+		ret = -EFAULT;
+		goto bail;
+	}
+
+	consumed = sizeof(cmd.type);
+
+	switch (cmd.type) {
+	case IPATH_CMD_USER_INIT:
+		copy = sizeof(cmd.cmd.user_info);
+		dest = &cmd.cmd.user_info;
+		src = &ucmd->cmd.user_info;
+		break;
+	case IPATH_CMD_RECV_CTRL:
+		copy = sizeof(cmd.cmd.recv_ctrl);
+		dest = &cmd.cmd.recv_ctrl;
+		src = &ucmd->cmd.recv_ctrl;
+		break;
+	case IPATH_CMD_PORT_INFO:
+		copy = sizeof(cmd.cmd.port_info);
+		dest = &cmd.cmd.port_info;
+		src = &ucmd->cmd.port_info;
+		break;
+	case IPATH_CMD_TID_UPDATE:
+	case IPATH_CMD_TID_FREE:
+		copy = sizeof(cmd.cmd.tid_info);
+		dest = &cmd.cmd.tid_info;
+		src = &ucmd->cmd.tid_info;
+		break;
+	case IPATH_CMD_SET_PART_KEY:
+		copy = sizeof(cmd.cmd.part_key);
+		dest = &cmd.cmd.part_key;
+		src = &ucmd->cmd.part_key;
+		break;
+	default:
+		ret = -EINVAL;
+		goto bail;
+	}
+
+	if ((count - consumed) < copy) {
+		ret = -EINVAL;
+		goto bail;
+	}
+
+	if (copy_from_user(dest, src, copy)) {
+		ret = -EFAULT;
+		goto bail;
+	}
+
+	consumed += copy;
+	pd = port_fp(fp);
+
+	switch (cmd.type) {
+	case IPATH_CMD_USER_INIT:
+		ret = ipath_do_user_init(pd, &cmd.cmd.user_info);
+		if (ret < 0)
+			goto bail;
+		ret = ipath_get_base_info(
+			pd, (void __user *) (unsigned long)
+			cmd.cmd.user_info.spu_base_info,
+			cmd.cmd.user_info.spu_base_info_size);
+		break;
+	case IPATH_CMD_RECV_CTRL:
+		ret = ipath_manage_rcvq(pd, cmd.cmd.recv_ctrl);
+		break;
+	case IPATH_CMD_PORT_INFO:
+		ret = ipath_port_info(pd,
+				      (struct ipath_port_info __user *)
+				      (unsigned long) cmd.cmd.port_info);
+		break;
+	case IPATH_CMD_TID_UPDATE:
+		ret = ipath_tid_update(pd, &cmd.cmd.tid_info);
+		break;
+	case IPATH_CMD_TID_FREE:
+		ret = ipath_tid_free(pd, &cmd.cmd.tid_info);
+		break;
+	case IPATH_CMD_SET_PART_KEY:
+		ret = ipath_set_part_key(pd, cmd.cmd.part_key);
+		break;
+	}
+
+	if (ret >= 0)
+		ret = consumed;
+
+bail:
+	return ret;
+}
+
+static struct class *ipath_class;
+
+static int init_cdev(int minor, char *name, struct file_operations *fops,
+		     struct cdev **cdevp, struct class_device **class_devp)
+{
+	const dev_t dev = MKDEV(IPATH_MAJOR, minor);
+	struct cdev *cdev = NULL;
+	struct class_device *class_dev = NULL;
+	int ret;
+
+	cdev = cdev_alloc();
+	if (!cdev) {
+		printk(KERN_ERR IPATH_DRV_NAME
+		       ": Could not allocate cdev for minor %d, %s\n",
+		       minor, name);
+		ret = -ENOMEM;
+		goto done;
+	}
+
+	cdev->owner = THIS_MODULE;
+	cdev->ops = fops;
+	kobject_set_name(&cdev->kobj, name);
+
+	ret = cdev_add(cdev, dev, 1);
+	if (ret < 0) {
+		printk(KERN_ERR IPATH_DRV_NAME
+		       ": Could not add cdev for minor %d, %s (err %d)\n",
+		       minor, name, -ret);
+		goto err_cdev;
+	}
+
+	class_dev = class_device_create(ipath_class, NULL, dev, NULL, name);
+
+	if (IS_ERR(class_dev)) {
+		ret = PTR_ERR(class_dev);
+		printk(KERN_ERR IPATH_DRV_NAME ": Could not create "
+		       "class_dev for minor %d, %s (err %d)\n",
+		       minor, name, -ret);
+		goto err_cdev;
+	}
+
+	goto done;
+
+err_cdev:
+	cdev_del(cdev);
+	cdev = NULL;
+
+done:
+	if (ret >= 0) {
+		*cdevp = cdev;
+		*class_devp = class_dev;
+	} else {
+		*cdevp = NULL;
+		*class_devp = NULL;
+	}
+
+	return ret;
+}
+
+int ipath_cdev_init(int minor, char *name, struct file_operations *fops,
+		    struct cdev **cdevp, struct class_device **class_devp)
+{
+	return init_cdev(minor, name, fops, cdevp, class_devp);
+}
+
+static void cleanup_cdev(struct cdev **cdevp,
+			 struct class_device **class_devp)
+{
+	struct class_device *class_dev = *class_devp;
+
+	if (class_dev) {
+		class_device_unregister(class_dev);
+		*class_devp = NULL;
+	}
+
+	if (*cdevp) {
+		cdev_del(*cdevp);
+		*cdevp = NULL;
+	}
+}
+
+void ipath_cdev_cleanup(struct cdev **cdevp,
+			struct class_device **class_devp)
+{
+	cleanup_cdev(cdevp, class_devp);
+}
+
+static struct cdev *wildcard_cdev;
+static struct class_device *wildcard_class_dev;
+
+static const dev_t dev = MKDEV(IPATH_MAJOR, 0);
+
+static int user_init(void)
+{
+	int ret;
+
+	ret = register_chrdev_region(dev, IPATH_NMINORS, IPATH_DRV_NAME);
+	if (ret < 0) {
+		printk(KERN_ERR IPATH_DRV_NAME ": Could not register "
+		       "chrdev region (err %d)\n", -ret);
+		goto done;
+	}
+
+	ipath_class = class_create(THIS_MODULE, IPATH_DRV_NAME);
+
+	if (IS_ERR(ipath_class)) {
+		ret = PTR_ERR(ipath_class);
+		printk(KERN_ERR IPATH_DRV_NAME ": Could not create "
+		       "device class (err %d)\n", -ret);
+		goto bail;
+	}
+
+	goto done;
+bail:
+	unregister_chrdev_region(dev, IPATH_NMINORS);
+done:
+	return ret;
+}
+
+static void user_cleanup(void)
+{
+	if (ipath_class) {
+		class_destroy(ipath_class);
+		ipath_class = NULL;
+	}
+
+	unregister_chrdev_region(dev, IPATH_NMINORS);
+}
+
+static atomic_t user_count = ATOMIC_INIT(0);
+static atomic_t user_setup = ATOMIC_INIT(0);
+
+int ipath_user_add(struct ipath_devdata *dd)
+{
+	char name[10];
+	int ret;
+
+	if (atomic_inc_return(&user_count) == 1) {
+		ret = user_init();
+		if (ret < 0) {
+			ipath_dev_err(dd, "Unable to set up user support: "
+				      "error %d\n", -ret);
+			goto bail;
+		}
+		ret = ipath_diag_init();
+		if (ret < 0) {
+			ipath_dev_err(dd, "Unable to set up diag support: "
+				      "error %d\n", -ret);
+			goto bail_sma;
+		}
+
+		ret = init_cdev(0, "ipath", &ipath_file_ops, &wildcard_cdev,
+				&wildcard_class_dev);
+		if (ret < 0) {
+			ipath_dev_err(dd, "Could not create wildcard "
+				      "minor: error %d\n", -ret);
+			goto bail_diag;
+		}
+
+		atomic_set(&user_setup, 1);
+	}
+
+	snprintf(name, sizeof(name), "ipath%d", dd->ipath_unit);
+
+	ret = init_cdev(dd->ipath_unit + 1, name, &ipath_file_ops,
+			&dd->cdev, &dd->class_dev);
+	if (ret < 0)
+		ipath_dev_err(dd, "Could not create user minor %d, %s\n",
+			      dd->ipath_unit + 1, name);
+
+	goto bail;
+
+bail_diag:
+	ipath_diag_cleanup();
+bail_sma:
+	user_cleanup();
+bail:
+	return ret;
+}
+
+void ipath_user_del(struct ipath_devdata *dd)
+{
+	cleanup_cdev(&dd->cdev, &dd->class_dev);
+
+	if (atomic_dec_return(&user_count) == 0) {
+		if (atomic_read(&user_setup) == 0)
+			goto bail;
+
+		cleanup_cdev(&wildcard_cdev, &wildcard_class_dev);
+		ipath_diag_cleanup();
+		user_cleanup();
+
+		atomic_set(&user_setup, 0);
+	}
+bail:
+	return;
+}

drivers/infiniband/hw/ipath/ipath_user_pages.c

@@ -0,0 +1,207 @@
+/*
+ * 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/mm.h>
+#include <linux/device.h>
+
+#include "ipath_kernel.h"
+
+static void __ipath_release_user_pages(struct page **p, size_t num_pages,
+				   int dirty)
+{
+	size_t i;
+
+	for (i = 0; i < num_pages; i++) {
+		ipath_cdbg(MM, "%lu/%lu put_page %p\n", (unsigned long) i,
+			   (unsigned long) num_pages, p[i]);
+		if (dirty)
+			set_page_dirty_lock(p[i]);
+		put_page(p[i]);
+	}
+}
+
+/* call with current->mm->mmap_sem held */
+static int __get_user_pages(unsigned long start_page, size_t num_pages,
+			struct page **p, struct vm_area_struct **vma)
+{
+	unsigned long lock_limit;
+	size_t got;
+	int ret;
+
+#if 0
+	/*
+	 * XXX - causes MPI programs to fail, haven't had time to check
+	 * yet
+	 */
+	if (!capable(CAP_IPC_LOCK)) {
+		ret = -EPERM;
+		goto bail;
+	}
+#endif
+
+	lock_limit = current->signal->rlim[RLIMIT_MEMLOCK].rlim_cur >>
+		PAGE_SHIFT;
+
+	if (num_pages > lock_limit) {
+		ret = -ENOMEM;
+		goto bail;
+	}
+
+	ipath_cdbg(VERBOSE, "pin %lx pages from vaddr %lx\n",
+		   (unsigned long) num_pages, start_page);
+
+	for (got = 0; got < num_pages; got += ret) {
+		ret = get_user_pages(current, current->mm,
+				     start_page + got * PAGE_SIZE,
+				     num_pages - got, 1, 1,
+				     p + got, vma);
+		if (ret < 0)
+			goto bail_release;
+	}
+
+	current->mm->locked_vm += num_pages;
+
+	ret = 0;
+	goto bail;
+
+bail_release:
+	__ipath_release_user_pages(p, got, 0);
+bail:
+	return ret;
+}
+
+/**
+ * ipath_get_user_pages - lock user pages into memory
+ * @start_page: the start page
+ * @num_pages: the number of pages
+ * @p: the output page structures
+ *
+ * This function takes a given start page (page aligned user virtual
+ * address) and pins it and the following specified number of pages.  For
+ * now, num_pages is always 1, but that will probably change at some point
+ * (because caller is doing expected sends on a single virtually contiguous
+ * buffer, so we can do all pages at once).
+ */
+int ipath_get_user_pages(unsigned long start_page, size_t num_pages,
+			 struct page **p)
+{
+	int ret;
+
+	down_write(&current->mm->mmap_sem);
+
+	ret = __get_user_pages(start_page, num_pages, p, NULL);
+
+	up_write(&current->mm->mmap_sem);
+
+	return ret;
+}
+
+/**
+ * ipath_get_user_pages_nocopy - lock a single page for I/O and mark shared
+ * @start_page: the page to lock
+ * @p: the output page structure
+ *
+ * This is similar to ipath_get_user_pages, but it's always one page, and we
+ * mark the page as locked for I/O, and shared.  This is used for the user
+ * process page that contains the destination address for the rcvhdrq tail
+ * update, so we need to have the vma. If we don't do this, the page can be
+ * taken away from us on fork, even if the child never touches it, and then
+ * the user process never sees the tail register updates.
+ */
+int ipath_get_user_pages_nocopy(unsigned long page, struct page **p)
+{
+	struct vm_area_struct *vma;
+	int ret;
+
+	down_write(&current->mm->mmap_sem);
+
+	ret = __get_user_pages(page, 1, p, &vma);
+
+	up_write(&current->mm->mmap_sem);
+
+	return ret;
+}
+
+void ipath_release_user_pages(struct page **p, size_t num_pages)
+{
+	down_write(&current->mm->mmap_sem);
+
+	__ipath_release_user_pages(p, num_pages, 1);
+
+	current->mm->locked_vm -= num_pages;
+
+	up_write(&current->mm->mmap_sem);
+}
+
+struct ipath_user_pages_work {
+	struct work_struct work;
+	struct mm_struct *mm;
+	unsigned long num_pages;
+};
+
+static void user_pages_account(void *ptr)
+{
+	struct ipath_user_pages_work *work = ptr;
+
+	down_write(&work->mm->mmap_sem);
+	work->mm->locked_vm -= work->num_pages;
+	up_write(&work->mm->mmap_sem);
+	mmput(work->mm);
+	kfree(work);
+}
+
+void ipath_release_user_pages_on_close(struct page **p, size_t num_pages)
+{
+	struct ipath_user_pages_work *work;
+	struct mm_struct *mm;
+
+	__ipath_release_user_pages(p, num_pages, 1);
+
+	mm = get_task_mm(current);
+	if (!mm)
+		goto bail;
+
+	work = kmalloc(sizeof(*work), GFP_KERNEL);
+	if (!work)
+		goto bail_mm;
+
+	goto bail;
+
+	INIT_WORK(&work->work, user_pages_account, work);
+	work->mm = mm;
+	work->num_pages = num_pages;
+
+bail_mm:
+	mmput(mm);
+bail:
+	return;
+}