Add the rt linux 4.1.3-rt3 as base
[kvmfornfv.git] / kernel / drivers / infiniband / hw / ipath / ipath_file_ops.c
diff --git a/kernel/drivers/infiniband/hw/ipath/ipath_file_ops.c b/kernel/drivers/infiniband/hw/ipath/ipath_file_ops.c
new file mode 100644 (file)
index 0000000..450d159
--- /dev/null
@@ -0,0 +1,2620 @@
+/*
+ * 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.
+ */
+
+#include <linux/pci.h>
+#include <linux/poll.h>
+#include <linux/cdev.h>
+#include <linux/swap.h>
+#include <linux/export.h>
+#include <linux/vmalloc.h>
+#include <linux/slab.h>
+#include <linux/highmem.h>
+#include <linux/io.h>
+#include <linux/jiffies.h>
+#include <linux/cpu.h>
+#include <linux/uio.h>
+#include <asm/pgtable.h>
+
+#include "ipath_kernel.h"
+#include "ipath_common.h"
+#include "ipath_user_sdma.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 ssize_t ipath_write_iter(struct kiocb *, struct iov_iter *from);
+static unsigned int ipath_poll(struct file *, struct poll_table_struct *);
+static int ipath_mmap(struct file *, struct vm_area_struct *);
+
+/*
+ * This is really, really weird shit - write() and writev() here
+ * have completely unrelated semantics.  Sucky userland ABI,
+ * film at 11.
+ */
+static const struct file_operations ipath_file_ops = {
+       .owner = THIS_MODULE,
+       .write = ipath_write,
+       .write_iter = ipath_write_iter,
+       .open = ipath_open,
+       .release = ipath_close,
+       .poll = ipath_poll,
+       .mmap = ipath_mmap,
+       .llseek = noop_llseek,
+};
+
+/*
+ * Convert kernel virtual addresses to physical addresses so they don't
+ * potentially conflict with the chip addresses used as mmap offsets.
+ * It doesn't really matter what mmap offset we use as long as we can
+ * interpret it correctly.
+ */
+static u64 cvt_kvaddr(void *p)
+{
+       struct page *page;
+       u64 paddr = 0;
+
+       page = vmalloc_to_page(p);
+       if (page)
+               paddr = page_to_pfn(page) << PAGE_SHIFT;
+
+       return paddr;
+}
+
+static int ipath_get_base_info(struct file *fp,
+                              void __user *ubase, size_t ubase_size)
+{
+       struct ipath_portdata *pd = port_fp(fp);
+       int ret = 0;
+       struct ipath_base_info *kinfo = NULL;
+       struct ipath_devdata *dd = pd->port_dd;
+       unsigned subport_cnt;
+       int shared, master;
+       size_t sz;
+
+       subport_cnt = pd->port_subport_cnt;
+       if (!subport_cnt) {
+               shared = 0;
+               master = 0;
+               subport_cnt = 1;
+       } else {
+               shared = 1;
+               master = !subport_fp(fp);
+       }
+
+       sz = sizeof(*kinfo);
+       /* If port sharing is not requested, allow the old size structure */
+       if (!shared)
+               sz -= 7 * sizeof(u64);
+       if (ubase_size < sz) {
+               ipath_cdbg(PROC,
+                          "Base size %zu, need %zu (version mismatch?)\n",
+                          ubase_size, sz);
+               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 / subport_cnt;
+       if (master)
+               kinfo->spi_tidcnt += dd->ipath_rcvtidcnt % subport_cnt;
+       /*
+        * 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 change 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_rcvhdr_tailaddr = (u64) pd->port_rcvhdrqtailaddr_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;
+       if (!shared) {
+               kinfo->spi_piocnt = pd->port_piocnt;
+               kinfo->spi_piobufbase = (u64) pd->port_piobufs;
+               kinfo->__spi_uregbase = (u64) dd->ipath_uregbase +
+                       dd->ipath_ureg_align * pd->port_port;
+       } else if (master) {
+               kinfo->spi_piocnt = (pd->port_piocnt / subport_cnt) +
+                                   (pd->port_piocnt % subport_cnt);
+               /* Master's PIO buffers are after all the slave's */
+               kinfo->spi_piobufbase = (u64) pd->port_piobufs +
+                       dd->ipath_palign *
+                       (pd->port_piocnt - kinfo->spi_piocnt);
+       } else {
+               unsigned slave = subport_fp(fp) - 1;
+
+               kinfo->spi_piocnt = pd->port_piocnt / subport_cnt;
+               kinfo->spi_piobufbase = (u64) pd->port_piobufs +
+                       dd->ipath_palign * kinfo->spi_piocnt * slave;
+       }
+
+       if (shared) {
+               kinfo->spi_port_uregbase = (u64) dd->ipath_uregbase +
+                       dd->ipath_ureg_align * pd->port_port;
+               kinfo->spi_port_rcvegrbuf = kinfo->spi_rcv_egrbufs;
+               kinfo->spi_port_rcvhdr_base = kinfo->spi_rcvhdr_base;
+               kinfo->spi_port_rcvhdr_tailaddr = kinfo->spi_rcvhdr_tailaddr;
+
+               kinfo->__spi_uregbase = cvt_kvaddr(pd->subport_uregbase +
+                       PAGE_SIZE * subport_fp(fp));
+
+               kinfo->spi_rcvhdr_base = cvt_kvaddr(pd->subport_rcvhdr_base +
+                       pd->port_rcvhdrq_size * subport_fp(fp));
+               kinfo->spi_rcvhdr_tailaddr = 0;
+               kinfo->spi_rcv_egrbufs = cvt_kvaddr(pd->subport_rcvegrbuf +
+                       pd->port_rcvegrbuf_chunks * pd->port_rcvegrbuf_size *
+                       subport_fp(fp));
+
+               kinfo->spi_subport_uregbase =
+                       cvt_kvaddr(pd->subport_uregbase);
+               kinfo->spi_subport_rcvegrbuf =
+                       cvt_kvaddr(pd->subport_rcvegrbuf);
+               kinfo->spi_subport_rcvhdr_base =
+                       cvt_kvaddr(pd->subport_rcvhdr_base);
+               ipath_cdbg(PROC, "port %u flags %x %llx %llx %llx\n",
+                       kinfo->spi_port, kinfo->spi_runtime_flags,
+                       (unsigned long long) kinfo->spi_subport_uregbase,
+                       (unsigned long long) kinfo->spi_subport_rcvegrbuf,
+                       (unsigned long long) kinfo->spi_subport_rcvhdr_base);
+       }
+
+       /*
+        * All user buffers are 2KB buffers.  If we ever support
+        * giving 4KB buffers to user processes, this will need some
+        * work.
+        */
+       kinfo->spi_pioindex = (kinfo->spi_piobufbase -
+               (dd->ipath_piobufbase & 0xffffffff)) / dd->ipath_palign;
+       kinfo->spi_pioalign = dd->ipath_palign;
+
+       kinfo->spi_qpair = IPATH_KD_QP;
+       /*
+        * user mode PIO buffers are always 2KB, even when 4KB can
+        * be received, and sent via the kernel; this is ibmaxlen
+        * for 2K MTU.
+        */
+       kinfo->spi_piosize = dd->ipath_piosize2k - 2 * sizeof(u32);
+       kinfo->spi_mtu = dd->ipath_ibmaxlen;    /* maxlen, not ibmtu */
+       kinfo->spi_port = pd->port_port;
+       kinfo->spi_subport = subport_fp(fp);
+       kinfo->spi_sw_version = IPATH_KERN_SWVERSION;
+       kinfo->spi_hw_version = dd->ipath_revision;
+
+       if (master) {
+               kinfo->spi_runtime_flags |= IPATH_RUNTIME_MASTER;
+       }
+
+       sz = (ubase_size < sizeof(*kinfo)) ? ubase_size : sizeof(*kinfo);
+       if (copy_to_user(ubase, kinfo, sz))
+               ret = -EFAULT;
+
+bail:
+       kfree(kinfo);
+       return ret;
+}
+
+/**
+ * ipath_tid_update - update a port TID
+ * @pd: the port
+ * @fp: the ipath device file
+ * @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, struct file *fp,
+                           const struct ipath_tid_info *ti)
+{
+       int ret = 0, ntids;
+       u32 tid, porttid, cnt, i, tidcnt, tidoff;
+       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;
+       unsigned subport = subport_fp(fp);
+
+       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;
+       }
+       porttid = pd->port_port * dd->ipath_rcvtidcnt;
+       if (!pd->port_subport_cnt) {
+               tidcnt = dd->ipath_rcvtidcnt;
+               tid = pd->port_tidcursor;
+               tidoff = 0;
+       } else if (!subport) {
+               tidcnt = (dd->ipath_rcvtidcnt / pd->port_subport_cnt) +
+                        (dd->ipath_rcvtidcnt % pd->port_subport_cnt);
+               tidoff = dd->ipath_rcvtidcnt - tidcnt;
+               porttid += tidoff;
+               tid = tidcursor_fp(fp);
+       } else {
+               tidcnt = dd->ipath_rcvtidcnt / pd->port_subport_cnt;
+               tidoff = tidcnt * (subport - 1);
+               porttid += tidoff;
+               tid = tidcursor_fp(fp);
+       }
+       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)[tidoff];
+       tidlist = &((u16 *) &pagep[dd->ipath_rcvtidcnt])[tidoff];
+
+       memset(tidmap, 0, sizeof(tidmap));
+       /* before decrement; chip actual # */
+       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 + tidoff;
+               ipath_cdbg(VERBOSE, "Updating idx %u to TID %u, "
+                          "vaddr %lx\n", i, tid + tidoff, vaddr);
+               /* we "know" system pages and TID pages are same size */
+               dd->ipath_pageshadow[porttid + tid] = pagep[i];
+               dd->ipath_physshadow[porttid + tid] = ipath_map_page(
+                       dd->pcidev, pagep[i], 0, PAGE_SIZE,
+                       PCI_DMA_FROMDEVICE);
+               /*
+                * don't need atomic or it's overhead
+                */
+               __set_bit(tid, tidmap);
+               physaddr = dd->ipath_physshadow[porttid + tid];
+               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], RCVHQ_RCV_TYPE_EXPECTED,
+                                   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],
+                                                   RCVHQ_RCV_TYPE_EXPECTED,
+                                                   dd->ipath_tidinvalid);
+                               pci_unmap_page(dd->pcidev,
+                                       dd->ipath_physshadow[porttid + tid],
+                                       PAGE_SIZE, PCI_DMA_FROMDEVICE);
+                               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;
+               if (!pd->port_subport_cnt)
+                       pd->port_tidcursor = tid;
+               else
+                       tidcursor_fp(fp) = 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
+ * @subport: the subport
+ * @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, unsigned subport,
+                         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;
+       if (!pd->port_subport_cnt)
+               tidcnt = dd->ipath_rcvtidcnt;
+       else if (!subport) {
+               tidcnt = (dd->ipath_rcvtidcnt / pd->port_subport_cnt) +
+                        (dd->ipath_rcvtidcnt % pd->port_subport_cnt);
+               porttid += dd->ipath_rcvtidcnt - tidcnt;
+       } else {
+               tidcnt = dd->ipath_rcvtidcnt / pd->port_subport_cnt;
+               porttid += tidcnt * (subport - 1);
+       }
+       tidbase = (u64 __iomem *) ((char __iomem *)(dd->ipath_kregbase) +
+                                  dd->ipath_rcvtidbase +
+                                  porttid * sizeof(*tidbase));
+
+       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]) {
+                       struct page *p;
+                       p = dd->ipath_pageshadow[porttid + tid];
+                       dd->ipath_pageshadow[porttid + tid] = NULL;
+                       ipath_cdbg(VERBOSE, "PID %u freeing TID %u\n",
+                                  pid_nr(pd->port_pid), tid);
+                       dd->ipath_f_put_tid(dd, &tidbase[tid],
+                                           RCVHQ_RCV_TYPE_EXPECTED,
+                                           dd->ipath_tidinvalid);
+                       pci_unmap_page(dd->pcidev,
+                               dd->ipath_physshadow[porttid + tid],
+                               PAGE_SIZE, PCI_DMA_FROMDEVICE);
+                       ipath_release_user_pages(&p, 1);
+                       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 == (IPATH_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
+ * @subport: the subport
+ * @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, unsigned subport,
+                            int start_stop)
+{
+       struct ipath_devdata *dd = pd->port_dd;
+
+       ipath_cdbg(PROC, "%sabling rcv for unit %u port %u:%u\n",
+                  start_stop ? "en" : "dis", dd->ipath_unit,
+                  pd->port_port, subport);
+       if (subport)
+               goto bail;
+       /* 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.
+                */
+               if (pd->port_rcvhdrtail_kvaddr)
+                       ipath_clear_rcvhdrtail(pd);
+               set_bit(dd->ipath_r_portenable_shift + pd->port_port,
+                       &dd->ipath_rcvctrl);
+       } else
+               clear_bit(dd->ipath_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 */
+       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.
+                */
+               ipath_read_ureg32(dd, ur_rcvhdrtail, pd->port_port);
+       }
+       /* always; new head should be equal to new tail; see above */
+bail:
+       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);
+       }
+}
+
+/*
+ * Initialize the port data with the receive buffer sizes
+ * so this can be done while the master port is locked.
+ * Otherwise, there is a race with a slave opening the port
+ * and seeing these fields uninitialized.
+ */
+static void init_user_egr_sizes(struct ipath_portdata *pd)
+{
+       struct ipath_devdata *dd = pd->port_dd;
+       unsigned egrperchunk, egrcnt, size;
+
+       /*
+        * 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 wasting
+        * additional memory.
+        */
+       size = 0x8000;
+       egrperchunk = size / dd->ipath_rcvegrbufsize;
+       egrcnt = dd->ipath_rcvegrcnt;
+       pd->port_rcvegrbuf_chunks = (egrcnt + egrperchunk - 1) / egrperchunk;
+       pd->port_rcvegrbufs_perchunk = egrperchunk;
+       pd->port_rcvegrbuf_size = size;
+}
+
+/**
+ * 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, egrperchunk, chunk, egrsize, egroff;
+       size_t size;
+       int ret;
+       gfp_t gfp_flags;
+
+       /*
+        * 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, and we can
+        * use compound pages.
+        */
+       gfp_flags = __GFP_WAIT | __GFP_IO | __GFP_COMP;
+
+       egrcnt = dd->ipath_rcvegrcnt;
+       /* TID number offset for this port */
+       egroff = (pd->port_port - 1) * egrcnt + dd->ipath_p0_rcvegrcnt;
+       egrsize = dd->ipath_rcvegrbufsize;
+       ipath_cdbg(VERBOSE, "Allocating %d egr buffers, at egrtid "
+                  "offset %x, egrsize %u\n", egrcnt, egroff, egrsize);
+
+       chunk = pd->port_rcvegrbuf_chunks;
+       egrperchunk = pd->port_rcvegrbufs_perchunk;
+       size = pd->port_rcvegrbuf_size;
+       pd->port_rcvegrbuf = kmalloc(chunk * sizeof(pd->port_rcvegrbuf[0]),
+                                    GFP_KERNEL);
+       if (!pd->port_rcvegrbuf) {
+               ret = -ENOMEM;
+               goto bail;
+       }
+       pd->port_rcvegrbuf_phys =
+               kmalloc(chunk * sizeof(pd->port_rcvegrbuf_phys[0]),
+                       GFP_KERNEL);
+       if (!pd->port_rcvegrbuf_phys) {
+               ret = -ENOMEM;
+               goto bail_rcvegrbuf;
+       }
+       for (e = 0; e < pd->port_rcvegrbuf_chunks; e++) {
+
+               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),
+                                           RCVHQ_RCV_TYPE_EAGER, 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]);
+
+       }
+       kfree(pd->port_rcvegrbuf_phys);
+       pd->port_rcvegrbuf_phys = NULL;
+bail_rcvegrbuf:
+       kfree(pd->port_rcvegrbuf);
+       pd->port_rcvegrbuf = NULL;
+bail:
+       return ret;
+}
+
+
+/* common code for the mappings on dma_alloc_coherent mem */
+static int ipath_mmap_mem(struct vm_area_struct *vma,
+       struct ipath_portdata *pd, unsigned len, int write_ok,
+       void *kvaddr, char *what)
+{
+       struct ipath_devdata *dd = pd->port_dd;
+       unsigned long pfn;
+       int ret;
+
+       if ((vma->vm_end - vma->vm_start) > len) {
+               dev_info(&dd->pcidev->dev,
+                        "FAIL on %s: len %lx > %x\n", what,
+                        vma->vm_end - vma->vm_start, len);
+               ret = -EFAULT;
+               goto bail;
+       }
+
+       if (!write_ok) {
+               if (vma->vm_flags & VM_WRITE) {
+                       dev_info(&dd->pcidev->dev,
+                                "%s must be mapped readonly\n", what);
+                       ret = -EPERM;
+                       goto bail;
+               }
+
+               /* don't allow them to later change with mprotect */
+               vma->vm_flags &= ~VM_MAYWRITE;
+       }
+
+       pfn = virt_to_phys(kvaddr) >> PAGE_SHIFT;
+       ret = remap_pfn_range(vma, vma->vm_start, pfn,
+                             len, vma->vm_page_prot);
+       if (ret)
+               dev_info(&dd->pcidev->dev, "%s port%u mmap of %lx, %x "
+                        "bytes r%c failed: %d\n", what, pd->port_port,
+                        pfn, len, write_ok?'w':'o', ret);
+       else
+               ipath_cdbg(VERBOSE, "%s port%u mmaped %lx, %x bytes "
+                          "r%c\n", what, pd->port_port, pfn, len,
+                          write_ok?'w':'o');
+bail:
+       return ret;
+}
+
+static int mmap_ureg(struct vm_area_struct *vma, struct ipath_devdata *dd,
+                    u64 ureg)
+{
+       unsigned long phys;
+       int ret;
+
+       /*
+        * This is real hardware, so use io_remap.  This is the mechanism
+        * for the user process to update the head registers for their port
+        * in the chip.
+        */
+       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 piobufs, unsigned piocnt)
+{
+       unsigned long phys;
+       int ret;
+
+       /*
+        * When we map the PIO buffers in the chip, we want to map them as
+        * writeonly, no read possible.   This prevents access to previous
+        * process data, and catches users who might try to read the i/o
+        * space due to a bug.
+        */
+       if ((vma->vm_end - vma->vm_start) > (piocnt * dd->ipath_palign)) {
+               dev_info(&dd->pcidev->dev, "FAIL mmap piobufs: "
+                        "reqlen %lx > PAGE\n",
+                        vma->vm_end - vma->vm_start);
+               ret = -EINVAL;
+               goto bail;
+       }
+
+       phys = dd->ipath_physaddr + piobufs;
+
+#if defined(__powerpc__)
+       /* There isn't a generic way to specify writethrough mappings */
+       pgprot_val(vma->vm_page_prot) |= _PAGE_NO_CACHE;
+       pgprot_val(vma->vm_page_prot) |= _PAGE_WRITETHRU;
+       pgprot_val(vma->vm_page_prot) &= ~_PAGE_GUARDED;
+#endif
+
+       /*
+        * don't allow them to later change to readable with mprotect (for when
+        * not initially mapped readable, as is normally the case)
+        */
+       vma->vm_flags &= ~VM_MAYREAD;
+       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;
+       unsigned long pfn;
+       int ret;
+
+       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 = -EINVAL;
+               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;
+       }
+       /* don't allow them to later change to writeable with mprotect */
+       vma->vm_flags &= ~VM_MAYWRITE;
+
+       start = vma->vm_start;
+
+       for (i = 0; i < pd->port_rcvegrbuf_chunks; i++, start += size) {
+               pfn = virt_to_phys(pd->port_rcvegrbuf[i]) >> PAGE_SHIFT;
+               ret = remap_pfn_range(vma, start, pfn, size,
+                                     vma->vm_page_prot);
+               if (ret < 0)
+                       goto bail;
+       }
+       ret = 0;
+
+bail:
+       return ret;
+}
+
+/*
+ * ipath_file_vma_fault - handle a VMA page fault.
+ */
+static int ipath_file_vma_fault(struct vm_area_struct *vma,
+                                       struct vm_fault *vmf)
+{
+       struct page *page;
+
+       page = vmalloc_to_page((void *)(vmf->pgoff << PAGE_SHIFT));
+       if (!page)
+               return VM_FAULT_SIGBUS;
+       get_page(page);
+       vmf->page = page;
+
+       return 0;
+}
+
+static const struct vm_operations_struct ipath_file_vm_ops = {
+       .fault = ipath_file_vma_fault,
+};
+
+static int mmap_kvaddr(struct vm_area_struct *vma, u64 pgaddr,
+                      struct ipath_portdata *pd, unsigned subport)
+{
+       unsigned long len;
+       struct ipath_devdata *dd;
+       void *addr;
+       size_t size;
+       int ret = 0;
+
+       /* If the port is not shared, all addresses should be physical */
+       if (!pd->port_subport_cnt)
+               goto bail;
+
+       dd = pd->port_dd;
+       size = pd->port_rcvegrbuf_chunks * pd->port_rcvegrbuf_size;
+
+       /*
+        * Each process has all the subport uregbase, rcvhdrq, and
+        * rcvegrbufs mmapped - as an array for all the processes,
+        * and also separately for this process.
+        */
+       if (pgaddr == cvt_kvaddr(pd->subport_uregbase)) {
+               addr = pd->subport_uregbase;
+               size = PAGE_SIZE * pd->port_subport_cnt;
+       } else if (pgaddr == cvt_kvaddr(pd->subport_rcvhdr_base)) {
+               addr = pd->subport_rcvhdr_base;
+               size = pd->port_rcvhdrq_size * pd->port_subport_cnt;
+       } else if (pgaddr == cvt_kvaddr(pd->subport_rcvegrbuf)) {
+               addr = pd->subport_rcvegrbuf;
+               size *= pd->port_subport_cnt;
+        } else if (pgaddr == cvt_kvaddr(pd->subport_uregbase +
+                                        PAGE_SIZE * subport)) {
+                addr = pd->subport_uregbase + PAGE_SIZE * subport;
+                size = PAGE_SIZE;
+        } else if (pgaddr == cvt_kvaddr(pd->subport_rcvhdr_base +
+                                pd->port_rcvhdrq_size * subport)) {
+                addr = pd->subport_rcvhdr_base +
+                        pd->port_rcvhdrq_size * subport;
+                size = pd->port_rcvhdrq_size;
+        } else if (pgaddr == cvt_kvaddr(pd->subport_rcvegrbuf +
+                               size * subport)) {
+                addr = pd->subport_rcvegrbuf + size * subport;
+                /* rcvegrbufs are read-only on the slave */
+                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;
+                }
+                /*
+                 * Don't allow permission to later change to writeable
+                 * with mprotect.
+                 */
+                vma->vm_flags &= ~VM_MAYWRITE;
+       } else {
+               goto bail;
+       }
+       len = vma->vm_end - vma->vm_start;
+       if (len > size) {
+               ipath_cdbg(MM, "FAIL: reqlen %lx > %zx\n", len, size);
+               ret = -EINVAL;
+               goto bail;
+       }
+
+       vma->vm_pgoff = (unsigned long) addr >> PAGE_SHIFT;
+       vma->vm_ops = &ipath_file_vm_ops;
+       vma->vm_flags |= VM_DONTEXPAND | VM_DONTDUMP;
+       ret = 1;
+
+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;
+       unsigned piobufs, piocnt;
+       int ret;
+
+       pd = port_fp(fp);
+       if (!pd) {
+               ret = -EINVAL;
+               goto bail;
+       }
+       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
+        * file offset passed via mmap().  For shared ports, this is the
+        * kernel vmalloc() address of the pages to share with the master.
+        * For non-shared or master ports, this is a physical address.
+        * We only do one mmap for each space mapped.
+        */
+       pgaddr = vma->vm_pgoff << PAGE_SHIFT;
+
+       /*
+        * Check for 0 in case one of the allocations failed, but user
+        * called mmap anyway.
+        */
+       if (!pgaddr)  {
+               ret = -EINVAL;
+               goto bail;
+       }
+
+       ipath_cdbg(MM, "pgaddr %llx vm_start=%lx len %lx port %u:%u:%u\n",
+                  (unsigned long long) pgaddr, vma->vm_start,
+                  vma->vm_end - vma->vm_start, dd->ipath_unit,
+                  pd->port_port, subport_fp(fp));
+
+       /*
+        * Physical addresses must fit in 40 bits for our hardware.
+        * Check for kernel virtual addresses first, anything else must
+        * match a HW or memory address.
+        */
+       ret = mmap_kvaddr(vma, pgaddr, pd, subport_fp(fp));
+       if (ret) {
+               if (ret > 0)
+                       ret = 0;
+               goto bail;
+       }
+
+       ureg = dd->ipath_uregbase + dd->ipath_ureg_align * pd->port_port;
+       if (!pd->port_subport_cnt) {
+               /* port is not shared */
+               piocnt = pd->port_piocnt;
+               piobufs = pd->port_piobufs;
+       } else if (!subport_fp(fp)) {
+               /* caller is the master */
+               piocnt = (pd->port_piocnt / pd->port_subport_cnt) +
+                        (pd->port_piocnt % pd->port_subport_cnt);
+               piobufs = pd->port_piobufs +
+                       dd->ipath_palign * (pd->port_piocnt - piocnt);
+       } else {
+               unsigned slave = subport_fp(fp) - 1;
+
+               /* caller is a slave */
+               piocnt = pd->port_piocnt / pd->port_subport_cnt;
+               piobufs = pd->port_piobufs + dd->ipath_palign * piocnt * slave;
+       }
+
+       if (pgaddr == ureg)
+               ret = mmap_ureg(vma, dd, ureg);
+       else if (pgaddr == piobufs)
+               ret = mmap_piobufs(vma, dd, pd, piobufs, piocnt);
+       else if (pgaddr == dd->ipath_pioavailregs_phys)
+               /* in-memory copy of pioavail registers */
+               ret = ipath_mmap_mem(vma, pd, PAGE_SIZE, 0,
+                                    (void *) dd->ipath_pioavailregs_dma,
+                                    "pioavail registers");
+       else if (pgaddr == pd->port_rcvegr_phys)
+               ret = mmap_rcvegrbufs(vma, pd);
+       else if (pgaddr == (u64) pd->port_rcvhdrq_phys)
+               /*
+                * The rcvhdrq itself; readonly except on HT (so have
+                * to allow writable mapping), multiple pages, contiguous
+                * from an i/o perspective.
+                */
+               ret = ipath_mmap_mem(vma, pd, pd->port_rcvhdrq_size, 1,
+                                    pd->port_rcvhdrq,
+                                    "rcvhdrq");
+       else if (pgaddr == (u64) pd->port_rcvhdrqtailaddr_phys)
+               /* in-memory copy of rcvhdrq tail register */
+               ret = ipath_mmap_mem(vma, pd, PAGE_SIZE, 0,
+                                    pd->port_rcvhdrtail_kvaddr,
+                                    "rcvhdrq tail");
+       else
+               ret = -EINVAL;
+
+       vma->vm_private_data = NULL;
+
+       if (ret < 0)
+               dev_info(&dd->pcidev->dev,
+                        "Failure %d on off %llx len %lx\n",
+                        -ret, (unsigned long long)pgaddr,
+                        vma->vm_end - vma->vm_start);
+bail:
+       return ret;
+}
+
+static unsigned ipath_poll_hdrqfull(struct ipath_portdata *pd)
+{
+       unsigned pollflag = 0;
+
+       if ((pd->poll_type & IPATH_POLL_TYPE_OVERFLOW) &&
+           pd->port_hdrqfull != pd->port_hdrqfull_poll) {
+               pollflag |= POLLIN | POLLRDNORM;
+               pd->port_hdrqfull_poll = pd->port_hdrqfull;
+       }
+
+       return pollflag;
+}
+
+static unsigned int ipath_poll_urgent(struct ipath_portdata *pd,
+                                     struct file *fp,
+                                     struct poll_table_struct *pt)
+{
+       unsigned pollflag = 0;
+       struct ipath_devdata *dd;
+
+       dd = pd->port_dd;
+
+       /* variable access in ipath_poll_hdrqfull() needs this */
+       rmb();
+       pollflag = ipath_poll_hdrqfull(pd);
+
+       if (pd->port_urgent != pd->port_urgent_poll) {
+               pollflag |= POLLIN | POLLRDNORM;
+               pd->port_urgent_poll = pd->port_urgent;
+       }
+
+       if (!pollflag) {
+               /* this saves a spin_lock/unlock in interrupt handler... */
+               set_bit(IPATH_PORT_WAITING_URG, &pd->port_flag);
+               /* flush waiting flag so don't miss an event... */
+               wmb();
+               poll_wait(fp, &pd->port_wait, pt);
+       }
+
+       return pollflag;
+}
+
+static unsigned int ipath_poll_next(struct ipath_portdata *pd,
+                                   struct file *fp,
+                                   struct poll_table_struct *pt)
+{
+       u32 head;
+       u32 tail;
+       unsigned pollflag = 0;
+       struct ipath_devdata *dd;
+
+       dd = pd->port_dd;
+
+       /* variable access in ipath_poll_hdrqfull() needs this */
+       rmb();
+       pollflag = ipath_poll_hdrqfull(pd);
+
+       head = ipath_read_ureg32(dd, ur_rcvhdrhead, pd->port_port);
+       if (pd->port_rcvhdrtail_kvaddr)
+               tail = ipath_get_rcvhdrtail(pd);
+       else
+               tail = ipath_read_ureg32(dd, ur_rcvhdrtail, pd->port_port);
+
+       if (head != tail)
+               pollflag |= POLLIN | POLLRDNORM;
+       else {
+               /* this saves a spin_lock/unlock in interrupt handler */
+               set_bit(IPATH_PORT_WAITING_RCV, &pd->port_flag);
+               /* flush waiting flag so we don't miss an event */
+               wmb();
+
+               set_bit(pd->port_port + dd->ipath_r_intravail_shift,
+                       &dd->ipath_rcvctrl);
+
+               ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
+                                dd->ipath_rcvctrl);
+
+               if (dd->ipath_rhdrhead_intr_off) /* arm rcv interrupt */
+                       ipath_write_ureg(dd, ur_rcvhdrhead,
+                                        dd->ipath_rhdrhead_intr_off | head,
+                                        pd->port_port);
+
+               poll_wait(fp, &pd->port_wait, pt);
+       }
+
+       return pollflag;
+}
+
+static unsigned int ipath_poll(struct file *fp,
+                              struct poll_table_struct *pt)
+{
+       struct ipath_portdata *pd;
+       unsigned pollflag;
+
+       pd = port_fp(fp);
+       if (!pd)
+               pollflag = 0;
+       else if (pd->poll_type & IPATH_POLL_TYPE_URGENT)
+               pollflag = ipath_poll_urgent(pd, fp, pt);
+       else
+               pollflag = ipath_poll_next(pd, fp, pt);
+
+       return pollflag;
+}
+
+static int ipath_supports_subports(int user_swmajor, int user_swminor)
+{
+       /* no subport implementation prior to software version 1.3 */
+       return (user_swmajor > 1) || (user_swminor >= 3);
+}
+
+static int ipath_compatible_subports(int user_swmajor, int user_swminor)
+{
+       /* this code is written long-hand for clarity */
+       if (IPATH_USER_SWMAJOR != user_swmajor) {
+               /* no promise of compatibility if major mismatch */
+               return 0;
+       }
+       if (IPATH_USER_SWMAJOR == 1) {
+               switch (IPATH_USER_SWMINOR) {
+               case 0:
+               case 1:
+               case 2:
+                       /* no subport implementation so cannot be compatible */
+                       return 0;
+               case 3:
+                       /* 3 is only compatible with itself */
+                       return user_swminor == 3;
+               default:
+                       /* >= 4 are compatible (or are expected to be) */
+                       return user_swminor >= 4;
+               }
+       }
+       /* make no promises yet for future major versions */
+       return 0;
+}
+
+static int init_subports(struct ipath_devdata *dd,
+                        struct ipath_portdata *pd,
+                        const struct ipath_user_info *uinfo)
+{
+       int ret = 0;
+       unsigned num_subports;
+       size_t size;
+
+       /*
+        * If the user is requesting zero subports,
+        * skip the subport allocation.
+        */
+       if (uinfo->spu_subport_cnt <= 0)
+               goto bail;
+
+       /* Self-consistency check for ipath_compatible_subports() */
+       if (ipath_supports_subports(IPATH_USER_SWMAJOR, IPATH_USER_SWMINOR) &&
+           !ipath_compatible_subports(IPATH_USER_SWMAJOR,
+                                      IPATH_USER_SWMINOR)) {
+               dev_info(&dd->pcidev->dev,
+                        "Inconsistent ipath_compatible_subports()\n");
+               goto bail;
+       }
+
+       /* Check for subport compatibility */
+       if (!ipath_compatible_subports(uinfo->spu_userversion >> 16,
+                                      uinfo->spu_userversion & 0xffff)) {
+               dev_info(&dd->pcidev->dev,
+                        "Mismatched user version (%d.%d) and driver "
+                        "version (%d.%d) while port sharing. Ensure "
+                         "that driver and library are from the same "
+                         "release.\n",
+                        (int) (uinfo->spu_userversion >> 16),
+                         (int) (uinfo->spu_userversion & 0xffff),
+                        IPATH_USER_SWMAJOR,
+                        IPATH_USER_SWMINOR);
+               goto bail;
+       }
+       if (uinfo->spu_subport_cnt > INFINIPATH_MAX_SUBPORT) {
+               ret = -EINVAL;
+               goto bail;
+       }
+
+       num_subports = uinfo->spu_subport_cnt;
+       pd->subport_uregbase = vzalloc(PAGE_SIZE * num_subports);
+       if (!pd->subport_uregbase) {
+               ret = -ENOMEM;
+               goto bail;
+       }
+       /* Note: pd->port_rcvhdrq_size isn't initialized yet. */
+       size = ALIGN(dd->ipath_rcvhdrcnt * dd->ipath_rcvhdrentsize *
+                    sizeof(u32), PAGE_SIZE) * num_subports;
+       pd->subport_rcvhdr_base = vzalloc(size);
+       if (!pd->subport_rcvhdr_base) {
+               ret = -ENOMEM;
+               goto bail_ureg;
+       }
+
+       pd->subport_rcvegrbuf = vzalloc(pd->port_rcvegrbuf_chunks *
+                                       pd->port_rcvegrbuf_size *
+                                       num_subports);
+       if (!pd->subport_rcvegrbuf) {
+               ret = -ENOMEM;
+               goto bail_rhdr;
+       }
+
+       pd->port_subport_cnt = uinfo->spu_subport_cnt;
+       pd->port_subport_id = uinfo->spu_subport_id;
+       pd->active_slaves = 1;
+       set_bit(IPATH_PORT_MASTER_UNINIT, &pd->port_flag);
+       goto bail;
+
+bail_rhdr:
+       vfree(pd->subport_rcvhdr_base);
+bail_ureg:
+       vfree(pd->subport_uregbase);
+       pd->subport_uregbase = NULL;
+bail:
+       return ret;
+}
+
+static int try_alloc_port(struct ipath_devdata *dd, int port,
+                         struct file *fp,
+                         const struct ipath_user_info *uinfo)
+{
+       struct ipath_portdata *pd;
+       int ret;
+
+       if (!(pd = dd->ipath_pd[port])) {
+               void *ptmp;
+
+               pd = 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 (!pd || !ptmp) {
+                       ipath_dev_err(dd, "Unable to allocate portdata "
+                                     "memory, failing open\n");
+                       ret = -ENOMEM;
+                       kfree(pd);
+                       kfree(ptmp);
+                       goto bail;
+               }
+               dd->ipath_pd[port] = pd;
+               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 (!pd->port_cnt) {
+               pd->userversion = uinfo->spu_userversion;
+               init_user_egr_sizes(pd);
+               if ((ret = init_subports(dd, pd, uinfo)) != 0)
+                       goto bail;
+               ipath_cdbg(PROC, "%s[%u] opened unit:port %u:%u\n",
+                          current->comm, current->pid, dd->ipath_unit,
+                          port);
+               pd->port_cnt = 1;
+               port_fp(fp) = pd;
+               pd->port_pid = get_pid(task_pid(current));
+               strlcpy(pd->port_comm, current->comm, sizeof(pd->port_comm));
+               ipath_stats.sps_ports++;
+               ret = 0;
+       } else
+               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,
+                         const struct ipath_user_info *uinfo)
+{
+       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 = 1; i < dd->ipath_cfgports; i++) {
+               ret = try_alloc_port(dd, i, fp, uinfo);
+               if (ret != -EBUSY)
+                       goto bail;
+       }
+       ret = -EBUSY;
+
+bail:
+       return ret;
+}
+
+static int find_best_unit(struct file *fp,
+                         const struct ipath_user_info *uinfo)
+{
+       int ret = 0, i, prefunit = -1, devmax;
+       int maxofallports, npresent, nup;
+       int ndev;
+
+       devmax = 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"
+        * InfiniPath chip 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 cpumask_empty() and cpumask_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 chips 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 (!cpumask_empty(tsk_cpus_allowed(current)) &&
+           !cpumask_full(tsk_cpus_allowed(current))) {
+               int ncpus = num_online_cpus(), curcpu = -1, nset = 0;
+               get_online_cpus();
+               for_each_online_cpu(i)
+                       if (cpumask_test_cpu(i, tsk_cpus_allowed(current))) {
+                               ipath_cdbg(PROC, "%s[%u] affinity set for "
+                                          "cpu %d/%d\n", current->comm,
+                                          current->pid, i, ncpus);
+                               curcpu = i;
+                               nset++;
+                       }
+               put_online_cpus();
+               if (curcpu != -1 && nset != ncpus) {
+                       if (npresent) {
+                               prefunit = curcpu / (ncpus / npresent);
+                               ipath_cdbg(PROC,"%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;
+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, uinfo);
+                       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 find_shared_port(struct file *fp,
+                           const struct ipath_user_info *uinfo)
+{
+       int devmax, ndev, i;
+       int ret = 0;
+
+       devmax = ipath_count_units(NULL, NULL, NULL);
+
+       for (ndev = 0; ndev < devmax; ndev++) {
+               struct ipath_devdata *dd = ipath_lookup(ndev);
+
+               if (!usable(dd))
+                       continue;
+               for (i = 1; i < dd->ipath_cfgports; i++) {
+                       struct ipath_portdata *pd = dd->ipath_pd[i];
+
+                       /* Skip ports which are not yet open */
+                       if (!pd || !pd->port_cnt)
+                               continue;
+                       /* Skip port if it doesn't match the requested one */
+                       if (pd->port_subport_id != uinfo->spu_subport_id)
+                               continue;
+                       /* Verify the sharing process matches the master */
+                       if (pd->port_subport_cnt != uinfo->spu_subport_cnt ||
+                           pd->userversion != uinfo->spu_userversion ||
+                           pd->port_cnt >= pd->port_subport_cnt) {
+                               ret = -EINVAL;
+                               goto done;
+                       }
+                       port_fp(fp) = pd;
+                       subport_fp(fp) = pd->port_cnt++;
+                       pd->port_subpid[subport_fp(fp)] =
+                               get_pid(task_pid(current));
+                       tidcursor_fp(fp) = 0;
+                       pd->active_slaves |= 1 << subport_fp(fp);
+                       ipath_cdbg(PROC,
+                                  "%s[%u] %u sharing %s[%u] unit:port %u:%u\n",
+                                  current->comm, current->pid,
+                                  subport_fp(fp),
+                                  pd->port_comm, pid_nr(pd->port_pid),
+                                  dd->ipath_unit, pd->port_port);
+                       ret = 1;
+                       goto done;
+               }
+       }
+
+done:
+       return ret;
+}
+
+static int ipath_open(struct inode *in, struct file *fp)
+{
+       /* The real work is performed later in ipath_assign_port() */
+       fp->private_data = kzalloc(sizeof(struct ipath_filedata), GFP_KERNEL);
+       return fp->private_data ? 0 : -ENOMEM;
+}
+
+/* Get port early, so can set affinity prior to memory allocation */
+static int ipath_assign_port(struct file *fp,
+                             const struct ipath_user_info *uinfo)
+{
+       int ret;
+       int i_minor;
+       unsigned swmajor, swminor;
+
+       /* Check to be sure we haven't already initialized this file */
+       if (port_fp(fp)) {
+               ret = -EINVAL;
+               goto done;
+       }
+
+       /* for now, if major version is different, bail */
+       swmajor = uinfo->spu_userversion >> 16;
+       if (swmajor != IPATH_USER_SWMAJOR) {
+               ipath_dbg("User major version %d not same as driver "
+                         "major %d\n", uinfo->spu_userversion >> 16,
+                         IPATH_USER_SWMAJOR);
+               ret = -ENODEV;
+               goto done;
+       }
+
+       swminor = uinfo->spu_userversion & 0xffff;
+       if (swminor != IPATH_USER_SWMINOR)
+               ipath_dbg("User minor version %d not same as driver "
+                         "minor %d\n", swminor, IPATH_USER_SWMINOR);
+
+       mutex_lock(&ipath_mutex);
+
+       if (ipath_compatible_subports(swmajor, swminor) &&
+           uinfo->spu_subport_cnt &&
+           (ret = find_shared_port(fp, uinfo))) {
+               if (ret > 0)
+                       ret = 0;
+               goto done_chk_sdma;
+       }
+
+       i_minor = iminor(file_inode(fp)) - IPATH_USER_MINOR_BASE;
+       ipath_cdbg(VERBOSE, "open on dev %lx (minor %d)\n",
+                  (long)file_inode(fp)->i_rdev, i_minor);
+
+       if (i_minor)
+               ret = find_free_port(i_minor - 1, fp, uinfo);
+       else
+               ret = find_best_unit(fp, uinfo);
+
+done_chk_sdma:
+       if (!ret) {
+               struct ipath_filedata *fd = fp->private_data;
+               const struct ipath_portdata *pd = fd->pd;
+               const struct ipath_devdata *dd = pd->port_dd;
+
+               fd->pq = ipath_user_sdma_queue_create(&dd->pcidev->dev,
+                                                     dd->ipath_unit,
+                                                     pd->port_port,
+                                                     fd->subport);
+
+               if (!fd->pq)
+                       ret = -ENOMEM;
+       }
+
+       mutex_unlock(&ipath_mutex);
+
+done:
+       return ret;
+}
+
+
+static int ipath_do_user_init(struct file *fp,
+                             const struct ipath_user_info *uinfo)
+{
+       int ret;
+       struct ipath_portdata *pd = port_fp(fp);
+       struct ipath_devdata *dd;
+       u32 head32;
+
+       /* Subports don't need to initialize anything since master did it. */
+       if (subport_fp(fp)) {
+               ret = wait_event_interruptible(pd->port_wait,
+                       !test_bit(IPATH_PORT_MASTER_UNINIT, &pd->port_flag));
+               goto done;
+       }
+
+       dd = pd->port_dd;
+
+       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 */
+
+       /* some ports may get extra buffers, calculate that here */
+       if (pd->port_port <= dd->ipath_ports_extrabuf)
+               pd->port_piocnt = dd->ipath_pbufsport + 1;
+       else
+               pd->port_piocnt = dd->ipath_pbufsport;
+
+       /* for right now, kernel piobufs are at end, so port 1 is at 0 */
+       if (pd->port_port <= dd->ipath_ports_extrabuf)
+               pd->port_pio_base = (dd->ipath_pbufsport + 1)
+                       * (pd->port_port - 1);
+       else
+               pd->port_pio_base = dd->ipath_ports_extrabuf +
+                       dd->ipath_pbufsport * (pd->port_port - 1);
+       pd->port_piobufs = dd->ipath_piobufbase +
+               pd->port_pio_base * dd->ipath_palign;
+       ipath_cdbg(VERBOSE, "piobuf base for port %u is 0x%x, piocnt %u,"
+               " first pio %u\n", pd->port_port, pd->port_piobufs,
+               pd->port_piocnt, pd->port_pio_base);
+       ipath_chg_pioavailkernel(dd, pd->port_pio_base, pd->port_piocnt, 0);
+
+       /*
+        * 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;
+
+       /*
+        * set the eager head register 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_rcvegrindextail, pd->port_port);
+       ipath_write_ureg(dd, ur_rcvegrindexhead, head32, pd->port_port);
+       pd->port_lastrcvhdrqtail = -1;
+       ipath_cdbg(VERBOSE, "Wrote port%d egrhead %x from tail regs\n",
+               pd->port_port, head32);
+       pd->port_tidcursor = 0; /* start at beginning after open */
+
+       /* initialize poll variables... */
+       pd->port_urgent = 0;
+       pd->port_urgent_poll = 0;
+       pd->port_hdrqfull_poll = pd->port_hdrqfull;
+
+       /*
+        * Now enable the port for receive.
+        * For chips that are set to DMA the tail register to memory
+        * when they change (and when the update bit transitions from
+        * 0 to 1.  So for those chips, we turn it off and then back on.
+        * This will (very briefly) affect any other open ports, but the
+        * duration is very short, and therefore isn't an issue.  We
+        * explicitly set the in-memory tail copy to 0 beforehand, so we
+        * don't have to wait to be sure the DMA update has happened
+        * (chip resets head/tail to 0 on transition to enable).
+        */
+       set_bit(dd->ipath_r_portenable_shift + pd->port_port,
+               &dd->ipath_rcvctrl);
+       if (!(dd->ipath_flags & IPATH_NODMA_RTAIL)) {
+               if (pd->port_rcvhdrtail_kvaddr)
+                       ipath_clear_rcvhdrtail(pd);
+               ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
+                       dd->ipath_rcvctrl &
+                       ~(1ULL << dd->ipath_r_tailupd_shift));
+       }
+       ipath_write_kreg(dd, dd->ipath_kregs->kr_rcvctrl,
+                        dd->ipath_rcvctrl);
+       /* Notify any waiting slaves */
+       if (pd->port_subport_cnt) {
+               clear_bit(IPATH_PORT_MASTER_UNINIT, &pd->port_flag);
+               wake_up(&pd->port_wait);
+       }
+done:
+       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++) {
+               struct page *ps = dd->ipath_pageshadow[i];
+
+               if (!ps)
+                       continue;
+
+               dd->ipath_pageshadow[i] = NULL;
+               pci_unmap_page(dd->pcidev, dd->ipath_physshadow[i],
+                       PAGE_SIZE, PCI_DMA_FROMDEVICE);
+               ipath_release_user_pages_on_close(&ps, 1);
+               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_filedata *fd;
+       struct ipath_portdata *pd;
+       struct ipath_devdata *dd;
+       unsigned long flags;
+       unsigned port;
+       struct pid *pid;
+
+       ipath_cdbg(VERBOSE, "close on dev %lx, private data %p\n",
+                  (long)in->i_rdev, fp->private_data);
+
+       mutex_lock(&ipath_mutex);
+
+       fd = fp->private_data;
+       fp->private_data = NULL;
+       pd = fd->pd;
+       if (!pd) {
+               mutex_unlock(&ipath_mutex);
+               goto bail;
+       }
+
+       dd = pd->port_dd;
+
+       /* drain user sdma queue */
+       ipath_user_sdma_queue_drain(dd, fd->pq);
+       ipath_user_sdma_queue_destroy(fd->pq);
+
+       if (--pd->port_cnt) {
+               /*
+                * XXX If the master closes the port before the slave(s),
+                * revoke the mmap for the eager receive queue so
+                * the slave(s) don't wait for receive data forever.
+                */
+               pd->active_slaves &= ~(1 << fd->subport);
+               put_pid(pd->port_subpid[fd->subport]);
+               pd->port_subpid[fd->subport] = NULL;
+               mutex_unlock(&ipath_mutex);
+               goto bail;
+       }
+       /* early; no interrupt users after this */
+       spin_lock_irqsave(&dd->ipath_uctxt_lock, flags);
+       port = pd->port_port;
+       dd->ipath_pd[port] = NULL;
+       pid = pd->port_pid;
+       pd->port_pid = NULL;
+       spin_unlock_irqrestore(&dd->ipath_uctxt_lock, flags);
+
+       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_cdbg(PROC, "port %u port_flag set: 0x%lx\n",
+                         pd->port_port, pd->port_flag);
+               pd->port_flag = 0;
+       }
+
+       if (dd->ipath_kregbase) {
+               /* atomically clear receive enable port and intr avail. */
+               clear_bit(dd->ipath_r_portenable_shift + port,
+                         &dd->ipath_rcvctrl);
+               clear_bit(pd->port_port + dd->ipath_r_intravail_shift,
+                         &dd->ipath_rcvctrl);
+               ipath_write_kreg( dd, dd->ipath_kregs->kr_rcvctrl,
+                       dd->ipath_rcvctrl);
+               /* and read back from chip to be sure that nothing
+                * else is in flight when we do the rest */
+               (void)ipath_read_kreg64(dd, dd->ipath_kregs->kr_scratch);
+
+               /* clean up the pkeys for this port user */
+               ipath_clean_part_key(pd, dd);
+               /*
+                * be paranoid, and never write 0's to these, just use an
+                * unused part of the port 0 tail page.  Of course,
+                * rcvhdraddr points to a large chunk of memory, so this
+                * could still trash things, but at least it won't trash
+                * page 0, and by disabling the port, it should stop "soon",
+                * even if a packet or two is in already in flight after we
+                * disabled the port.
+                */
+               ipath_write_kreg_port(dd,
+                       dd->ipath_kregs->kr_rcvhdrtailaddr, port,
+                       dd->ipath_dummy_hdrq_phys);
+               ipath_write_kreg_port(dd, dd->ipath_kregs->kr_rcvhdraddr,
+                       pd->port_port, dd->ipath_dummy_hdrq_phys);
+
+               ipath_disarm_piobufs(dd, pd->port_pio_base, pd->port_piocnt);
+               ipath_chg_pioavailkernel(dd, pd->port_pio_base,
+                       pd->port_piocnt, 1);
+
+               dd->ipath_f_clear_tids(dd, pd->port_port);
+
+               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, pid_nr(pid),
+                          dd->ipath_unit, port);
+       }
+
+       put_pid(pid);
+       mutex_unlock(&ipath_mutex);
+       ipath_free_pddata(dd, pd); /* after releasing the mutex */
+
+bail:
+       kfree(fd);
+       return ret;
+}
+
+static int ipath_port_info(struct ipath_portdata *pd, u16 subport,
+                          struct ipath_port_info __user *uinfo)
+{
+       struct ipath_port_info info;
+       int nup;
+       int ret;
+       size_t sz;
+
+       (void) ipath_count_units(NULL, &nup, NULL);
+       info.num_active = nup;
+       info.unit = pd->port_dd->ipath_unit;
+       info.port = pd->port_port;
+       info.subport = subport;
+       /* Don't return new fields if old library opened the port. */
+       if (ipath_supports_subports(pd->userversion >> 16,
+                                   pd->userversion & 0xffff)) {
+               /* Number of user ports available for this device. */
+               info.num_ports = pd->port_dd->ipath_cfgports - 1;
+               info.num_subports = pd->port_subport_cnt;
+               sz = sizeof(info);
+       } else
+               sz = sizeof(info) - 2 * sizeof(u16);
+
+       if (copy_to_user(uinfo, &info, sz)) {
+               ret = -EFAULT;
+               goto bail;
+       }
+       ret = 0;
+
+bail:
+       return ret;
+}
+
+static int ipath_get_slave_info(struct ipath_portdata *pd,
+                               void __user *slave_mask_addr)
+{
+       int ret = 0;
+
+       if (copy_to_user(slave_mask_addr, &pd->active_slaves, sizeof(u32)))
+               ret = -EFAULT;
+       return ret;
+}
+
+static int ipath_sdma_get_inflight(struct ipath_user_sdma_queue *pq,
+                                  u32 __user *inflightp)
+{
+       const u32 val = ipath_user_sdma_inflight_counter(pq);
+
+       if (put_user(val, inflightp))
+               return -EFAULT;
+
+       return 0;
+}
+
+static int ipath_sdma_get_complete(struct ipath_devdata *dd,
+                                  struct ipath_user_sdma_queue *pq,
+                                  u32 __user *completep)
+{
+       u32 val;
+       int err;
+
+       err = ipath_user_sdma_make_progress(dd, pq);
+       if (err < 0)
+               return err;
+
+       val = ipath_user_sdma_complete_counter(pq);
+       if (put_user(val, completep))
+               return -EFAULT;
+
+       return 0;
+}
+
+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_ASSIGN_PORT:
+       case __IPATH_CMD_USER_INIT:
+       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;
+       case __IPATH_CMD_SLAVE_INFO:
+               copy = sizeof(cmd.cmd.slave_mask_addr);
+               dest = &cmd.cmd.slave_mask_addr;
+               src = &ucmd->cmd.slave_mask_addr;
+               break;
+       case IPATH_CMD_PIOAVAILUPD:     // force an update of PIOAvail reg
+               copy = 0;
+               src = NULL;
+               dest = NULL;
+               break;
+       case IPATH_CMD_POLL_TYPE:
+               copy = sizeof(cmd.cmd.poll_type);
+               dest = &cmd.cmd.poll_type;
+               src = &ucmd->cmd.poll_type;
+               break;
+       case IPATH_CMD_ARMLAUNCH_CTRL:
+               copy = sizeof(cmd.cmd.armlaunch_ctrl);
+               dest = &cmd.cmd.armlaunch_ctrl;
+               src = &ucmd->cmd.armlaunch_ctrl;
+               break;
+       case IPATH_CMD_SDMA_INFLIGHT:
+               copy = sizeof(cmd.cmd.sdma_inflight);
+               dest = &cmd.cmd.sdma_inflight;
+               src = &ucmd->cmd.sdma_inflight;
+               break;
+       case IPATH_CMD_SDMA_COMPLETE:
+               copy = sizeof(cmd.cmd.sdma_complete);
+               dest = &cmd.cmd.sdma_complete;
+               src = &ucmd->cmd.sdma_complete;
+               break;
+       default:
+               ret = -EINVAL;
+               goto bail;
+       }
+
+       if (copy) {
+               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);
+       if (!pd && cmd.type != __IPATH_CMD_USER_INIT &&
+               cmd.type != IPATH_CMD_ASSIGN_PORT) {
+               ret = -EINVAL;
+               goto bail;
+       }
+
+       switch (cmd.type) {
+       case IPATH_CMD_ASSIGN_PORT:
+               ret = ipath_assign_port(fp, &cmd.cmd.user_info);
+               if (ret)
+                       goto bail;
+               break;
+       case __IPATH_CMD_USER_INIT:
+               /* backwards compatibility, get port first */
+               ret = ipath_assign_port(fp, &cmd.cmd.user_info);
+               if (ret)
+                       goto bail;
+               /* and fall through to current version. */
+       case IPATH_CMD_USER_INIT:
+               ret = ipath_do_user_init(fp, &cmd.cmd.user_info);
+               if (ret)
+                       goto bail;
+               ret = ipath_get_base_info(
+                       fp, (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, subport_fp(fp), cmd.cmd.recv_ctrl);
+               break;
+       case IPATH_CMD_PORT_INFO:
+               ret = ipath_port_info(pd, subport_fp(fp),
+                                     (struct ipath_port_info __user *)
+                                     (unsigned long) cmd.cmd.port_info);
+               break;
+       case IPATH_CMD_TID_UPDATE:
+               ret = ipath_tid_update(pd, fp, &cmd.cmd.tid_info);
+               break;
+       case IPATH_CMD_TID_FREE:
+               ret = ipath_tid_free(pd, subport_fp(fp), &cmd.cmd.tid_info);
+               break;
+       case IPATH_CMD_SET_PART_KEY:
+               ret = ipath_set_part_key(pd, cmd.cmd.part_key);
+               break;
+       case __IPATH_CMD_SLAVE_INFO:
+               ret = ipath_get_slave_info(pd,
+                                          (void __user *) (unsigned long)
+                                          cmd.cmd.slave_mask_addr);
+               break;
+       case IPATH_CMD_PIOAVAILUPD:
+               ipath_force_pio_avail_update(pd->port_dd);
+               break;
+       case IPATH_CMD_POLL_TYPE:
+               pd->poll_type = cmd.cmd.poll_type;
+               break;
+       case IPATH_CMD_ARMLAUNCH_CTRL:
+               if (cmd.cmd.armlaunch_ctrl)
+                       ipath_enable_armlaunch(pd->port_dd);
+               else
+                       ipath_disable_armlaunch(pd->port_dd);
+               break;
+       case IPATH_CMD_SDMA_INFLIGHT:
+               ret = ipath_sdma_get_inflight(user_sdma_queue_fp(fp),
+                                             (u32 __user *) (unsigned long)
+                                             cmd.cmd.sdma_inflight);
+               break;
+       case IPATH_CMD_SDMA_COMPLETE:
+               ret = ipath_sdma_get_complete(pd->port_dd,
+                                             user_sdma_queue_fp(fp),
+                                             (u32 __user *) (unsigned long)
+                                             cmd.cmd.sdma_complete);
+               break;
+       }
+
+       if (ret >= 0)
+               ret = consumed;
+
+bail:
+       return ret;
+}
+
+static ssize_t ipath_write_iter(struct kiocb *iocb, struct iov_iter *from)
+{
+       struct file *filp = iocb->ki_filp;
+       struct ipath_filedata *fp = filp->private_data;
+       struct ipath_portdata *pd = port_fp(filp);
+       struct ipath_user_sdma_queue *pq = fp->pq;
+
+       if (!iter_is_iovec(from) || !from->nr_segs)
+               return -EINVAL;
+
+       return ipath_user_sdma_writev(pd->port_dd, pq, from->iov, from->nr_segs);
+}
+
+static struct class *ipath_class;
+
+static int init_cdev(int minor, char *name, const struct file_operations *fops,
+                    struct cdev **cdevp, struct device **devp)
+{
+       const dev_t dev = MKDEV(IPATH_MAJOR, minor);
+       struct cdev *cdev = NULL;
+       struct device *device = 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;
+       }
+
+       device = device_create(ipath_class, NULL, dev, NULL, name);
+
+       if (IS_ERR(device)) {
+               ret = PTR_ERR(device);
+               printk(KERN_ERR IPATH_DRV_NAME ": Could not create "
+                      "device 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;
+               *devp = device;
+       } else {
+               *cdevp = NULL;
+               *devp = NULL;
+       }
+
+       return ret;
+}
+
+int ipath_cdev_init(int minor, char *name, const struct file_operations *fops,
+                   struct cdev **cdevp, struct device **devp)
+{
+       return init_cdev(minor, name, fops, cdevp, devp);
+}
+
+static void cleanup_cdev(struct cdev **cdevp,
+                        struct device **devp)
+{
+       struct device *dev = *devp;
+
+       if (dev) {
+               device_unregister(dev);
+               *devp = NULL;
+       }
+
+       if (*cdevp) {
+               cdev_del(*cdevp);
+               *cdevp = NULL;
+       }
+}
+
+void ipath_cdev_cleanup(struct cdev **cdevp,
+                       struct device **devp)
+{
+       cleanup_cdev(cdevp, devp);
+}
+
+static struct cdev *wildcard_cdev;
+static struct device *wildcard_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 = init_cdev(0, "ipath", &ipath_file_ops, &wildcard_cdev,
+                               &wildcard_dev);
+               if (ret < 0) {
+                       ipath_dev_err(dd, "Could not create wildcard "
+                                     "minor: error %d\n", -ret);
+                       goto bail_user;
+               }
+
+               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->user_cdev, &dd->user_dev);
+       if (ret < 0)
+               ipath_dev_err(dd, "Could not create user minor %d, %s\n",
+                             dd->ipath_unit + 1, name);
+
+       goto bail;
+
+bail_user:
+       user_cleanup();
+bail:
+       return ret;
+}
+
+void ipath_user_remove(struct ipath_devdata *dd)
+{
+       cleanup_cdev(&dd->user_cdev, &dd->user_dev);
+
+       if (atomic_dec_return(&user_count) == 0) {
+               if (atomic_read(&user_setup) == 0)
+                       goto bail;
+
+               cleanup_cdev(&wildcard_cdev, &wildcard_dev);
+               user_cleanup();
+
+               atomic_set(&user_setup, 0);
+       }
+bail:
+       return;
+}