Version:  2.6.24 2.6.25 2.6.26 2.6.27 2.6.28 2.6.29 2.6.30 2.6.31 2.6.32 2.6.33 2.6.34-rc2

Architecture:  x86 arm avr32 blackfin m68k m68knommu microblaze mips powerpc sh

   /*
    * 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/vmalloc.h>
  #include <linux/highmem.h>
  #include <linux/io.h>
  #include <linux/jiffies.h>
  #include <linux/smp_lock.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_writev(struct kiocb *, const struct iovec *,
                              unsigned long , loff_t);
  static unsigned int ipath_poll(struct file *, struct poll_table_struct *);
  static int ipath_mmap(struct file *, struct vm_area_struct *);
  
  static const struct file_operations ipath_file_ops = {
          .owner = THIS_MODULE,
          .write = ipath_write,
          .aio_write = ipath_writev,
          .open = ipath_open,
          .release = ipath_close,
          .poll = ipath_poll,
          .mmap = ipath_mmap
  };
  
  /*
   * 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_RESERVED | VM_DONTEXPAND;
         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 = vmalloc(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 = vmalloc(size);
         if (!pd->subport_rcvhdr_base) {
                 ret = -ENOMEM;
                 goto bail_ureg;
         }
 
         pd->subport_rcvegrbuf = vmalloc(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);
         memset(pd->subport_uregbase, 0, PAGE_SIZE * num_subports);
         memset(pd->subport_rcvhdr_base, 0, size);
         memset(pd->subport_rcvegrbuf, 0, pd->port_rcvegrbuf_chunks *
                                          pd->port_rcvegrbuf_size *
                                          num_subports);
         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(&current->cpus_allowed) &&
             !cpumask_full(&current->cpus_allowed)) {
                 int ncpus = num_online_cpus(), curcpu = -1, nset = 0;
                 for (i = 0; i < ncpus; i++)
                         if (cpumask_test_cpu(i, &current->cpus_allowed)) {
                                 ipath_cdbg(PROC, "%s[%u] affinity set for "
                                            "cpu %d/%d\n", current->comm,
                                            current->pid, i, ncpus);
                                 curcpu = i;
                                 nset++;
                         }
                 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(fp->f_path.dentry->d_inode) - IPATH_USER_MINOR_BASE;
         ipath_cdbg(VERBOSE, "open on dev %lx (minor %d)\n",
                    (long)fp->f_path.dentry->d_inode->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
          * explictly 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 = (struct ipath_filedata *) 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_writev(struct kiocb *iocb, const struct iovec *iov,
                             unsigned long dim, loff_t off)
 {
         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 (!dim)
                 return -EINVAL;
 
         return ipath_user_sdma_writev(pd->port_dd, pq, iov, dim);
 }
 
 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;
 }
 

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